| 1. |
- Alaridah, Nader, et al.
(författare)
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Impaired CXCR1-dependent oxidative defence in active tuberculosis patients.
- 2015
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Ingår i: Tuberculosis. - : Elsevier BV. - 1873-281X .- 1472-9792. ; 95:6, s. 744-750
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Tidskriftsartikel (refereegranskat)abstract
- Much of the pronounced host inflammatory response that occurs in tuberculosis (TB) is related to failed immunity against the invading pathogen. The G-protein coupled receptors CXCR1 and CXCR2 are implicated in important signal transduction pathways in lung inflammatory responses. We investigated the expression and function of these receptors in a simple whole blood model from 24 patients with pulmonary TB and in subjects with latent TB infection (LTBI). Healthy controls were recruited from close contacts to the pulmonary index patients. We found that pulmonary TB patients had significantly increased CXCR1 expression on blood cells compared to LTBI subjects and controls (p < 0.001). In contrast, LTBI subjects had a significant increase in CXCR2 expression compared to pulmonary TB patients (p < 0.001) and controls (p < 0.01). Leukocyte function, measured as oxidative capacity, was decreased in pulmonary TB patients compared to LTBI and controls (p < 0.001) and correlated with the increased CXCR1 expression. Leukocyte recruitment, measured as the expression of microRNA-223 was increased in pulmonary TB patients compared to LTBI (p < 0.05). We found that variations in receptor expression are linked to disease progression and affect the immune response against Mycobacterium tuberculosis (Mtb).
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| 2. |
- Alaridah, Nader, et al.
(författare)
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Mycobacteria Manipulate G-Protein-Coupled Receptors to Increase Mucosal Rac1 Expression in the Lungs
- 2017
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Ingår i: Journal of Innate Immunity. - : S. Karger AG. - 1662-811X .- 1662-8128. ; 9, s. 318-329
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium bovis bacille Calmette-Guérin (BCG) is currently the only approved vaccine against tuberculosis (TB). BCG mimics M. tuberculosis (Mtb) in its persistence in the body and is used as a benchmark to compare new vaccine candidates. BCG was originally designed for mucosal vaccination, but comprehensive knowledge about its interaction with epithelium is currently lacking. We used primary airway epithelial cells (AECs) and a murine model to investigate the initial events of mucosal BCG interactions. Furthermore, we analysed the impact of the G-protein-coupled receptors (GPCRs), CXCR1 and CXCR2, in this process, as these receptors were previously shown to be important during TB infection. BCG infection of AECs induced GPCR-dependent Rac1 up-regulation, resulting in actin redistribution. The altered distribution of the actin cytoskeleton involved the MAPK signalling pathway. Blocking of the CXCR1 or CXCR2 prior to infection decreased Rac1 expression, and increased epithelial transcriptional activity and epithelial cytokine production. BCG infection did not result in epithelial cell death as measured by p53 phosphorylation and annexin. This study demonstrated that BCG infection of AECs manipulated the GPCRs to suppress epithelial signalling pathways. Future vaccine strategies could thus be improved by targeting GPCRs.
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| 3. |
- Alaridah, Nader, et al.
(författare)
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Transmission dynamics study of tuberculosis isolates with whole genome sequencing in southern Sweden
- 2019
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Epidemiological contact tracing complemented with genotyping of clinical Mycobacterium tuberculosis isolates is important for understanding disease transmission. In Sweden, tuberculosis (TB) is mostly reported in migrant and homeless where epidemiologic contact tracing could pose a problem. This study compared epidemiologic linking with genotyping in a low burden country. Mycobacterium tuberculosis isolates (n = 93) collected at Scania University Hospital in Southern Sweden were analysed with the standard genotyping method mycobacterial interspersed repetitive units-variable number tandem repeats (MIRU-VNTR) and the results were compared with whole genome sequencing (WGS). Using a maximum of twelve single nucleotide polymorphisms (SNPs) as the upper threshold of genomic relatedness noted among hosts, we identified 18 clusters with WGS comprising 52 patients with overall pairwise genetic maximum distances ranging from zero to nine SNPs. MIRU-VNTR and WGS clustered the same isolates, although the distribution differed depending on MIRU-VNTR limitations. Both genotyping techniques identified clusters where epidemiologic linking was insufficient, although WGS had higher correlation with epidemiologic data. To summarize, WGS provided better resolution of transmission than MIRU-VNTR in a setting with low TB incidence. WGS predicted epidemiologic links better which could consolidate and correct the epidemiologically linked cases, avoiding thus false clustering.
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| 4. |
- Ambite, Ines, et al.
(författare)
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Susceptibility to urinary tract infection : Benefits and hazards of the antibacterial host response
- 2016
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Ingår i: Microbiology spectrum. - Washington, DC, USA : ASM Press. - 2165-0497. ; 4:3
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Forskningsöversikt (refereegranskat)abstract
- A paradigm shift is needed to improve and personalize the diagnosis of infectious disease and to select appropriate therapies. For many years, only the most severe and complicated bacterial infections received more detailed diagnostic and therapeutic attention as the efficiency of antibiotic therapy has guaranteed efficient treatment of patients suffering from the most common infections. Indeed, treatability almost became a rationale not to analyze bacterial and host parameters in these larger patient groups. Due to the rapid spread of antibiotic resistance, common infections like respiratory tract- or urinary-tract infections (UTIs) now pose new and significant therapeutic challenges. It is fortunate and timely that infectious disease research can offer such a wealth of new molecular information that is ready to use for the identification of susceptible patients and design of new suitable therapies. Paradoxically, the threat of antibiotic resistance may become a window of opportunity, by encouraging the implementation of new diagnostic and therapeutic approaches. The frequency of antibiotic resistance is rising rapidly in uropathogenic organisms and the molecular and genetic understanding of UTI susceptibility is quite advanced. More bold translation of the new molecular diagnostic and therapeutic tools would not just be possible but of great potential benefit in this patient group. This chapter reviews the molecular basis for susceptibility to UTI, including recent advances in genetics, and discusses the consequences for diagnosis and therapy. By dissecting the increasingly well-defined molecular interactions between bacteria and host and the molecular features of excessive bacterial virulence or host-response malfunction, it is becoming possible to isolate the defensive from the damaging aspects of the host response. Distinguishing "good" from "bad" inflammation has been a long-term quest of biomedical science and in UTI, patients need the "good" aspects of the inflammatory response to resist infection while avoiding the "bad" aspects, causing chronicity and tissue damage.
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| 5. |
- Andersson, Märta, et al.
(författare)
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Mycobacterium bovis bacilli Calmette-Guerin regulates leukocyte recruitment by modulating alveolar inflammatory responses.
- 2012
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Ingår i: Innate Immunity. - : SAGE Publications. - 1753-4267 .- 1753-4259. ; 18, s. 531-540
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Tidskriftsartikel (refereegranskat)abstract
- Leukocyte migration into the epithelial compartment is an important feature in the active phase of mycobacterial infections. In this study, we used the Transwell model to investigate the mechanisms behind mycobacteria-induced leukocyte recruitment and investigated the role of TLR2 and TLR4 in this process. Infection of epithelial cells resulted in significantly increased secretion of the neutrophil chemotactic CXCL8 and IL-6, but no secretion of monocyte chemotactic CCL2 or TNF-α was observed. In contrast to epithelial response, mycobacteria-infected neutrophils and monocytes secreted all these cytokines. Corresponding with epithelial cytokine response, mycobacterial infection of the epithelial cells increased neutrophil diapedesis, but decreased monocyte recruitment. However, monocyte recruitment towards mycobacteria infected epithelial cells significantly increased following addition of neutrophil pre-conditioned medium. Mycobacterial infection also increases alveolar epithelial expression of TLR2, but not TLR4, as analyzed by flow cytometry, Western blotting and visualized by confocal microscopy. Blocking of TLR2 inhibited neutrophil recruitment and cytokine secretion, while blocking of TLR4 had a lesser effect. To summarize, we found that primary alveolar epithelial cells produced a selective TLR2-dependent cytokine secretion upon mycobacterial infection. Furthermore, we found that cooperation between cells of the innate immunity is required in mounting proper antimicrobial defence.
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| 6. |
- Broman, M, et al.
(författare)
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Phosphate-containing dialysis solution prevents hypophosphatemia during continuous renal replacement therapy.
- 2011
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Ingår i: Acta Anaesthesiologica Scandinavica. - : Wiley. - 0001-5172. ; Dec, s. 39-45
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypophosphatemia occurs in up to 80% of the patients during continuous renal replacement therapy (CRRT). Phosphate supplementation is time-consuming and the phosphate level might be dangerously low before normophosphatemia is re-established. This study evaluated the possibility to prevent hypophosphatemia during CRRT treatment by using a new commercially available phosphate-containing dialysis fluid. Methods: Forty-two heterogeneous intensive care unit patients, admitted between January 2007 and July 2008, undergoing hemodiafiltration, were treated with a new Gambro dialysis solution with 1.2 mM phosphate (Phoxilium) or with standard medical treatment (Hemosol B0). The patients were divided into three groups: group 1 (n=14) receiving standard medical treatment and intravenous phosphate supplementation as required, group 2 (n=14) receiving the phosphate solution as dialysate solution and Hemosol B0 as replacement solution and group 3 (n=14) receiving the phosphate-containing solution as both dialysate and replacement solutions. Results: Standard medical treatment resulted in hypophosphatemia in 11 of 14 of the patients (group 1) compared with five of 14 in the patients receiving phosphate solution as the dialysate solution and Hemosol B0 as the replacement solution (group 2). Patients treated with the phosphate-containing dialysis solution (group 3) experienced stable serum phosphate levels throughout the study. Potassium, ionized calcium, magnesium, pH, pCO(2) and bicarbonate remained unchanged throughout the study. Conclusion: The new phosphate-containing replacement and dialysis solution reduces the variability of serum phosphate levels during CRRT and eliminates the incidence of hypophosphatemia.
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| 7. |
- Broman, Marcus, et al.
(författare)
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Simplified citrate anticoagulation for CRRT without calcium replacement.
- 2015
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Ingår i: ASAIO Journal. - 1538-943X. ; 61:4, s. 437-442
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Tidskriftsartikel (refereegranskat)abstract
- Since 2012 citrate anticoagulation is the recommended anticoagulation strategy for CRRT. The main drawback using citrate compared with heparin as anticoagulant is the need for calcium replacement and the rigorous control of calcium levels. This study investigated the possibility to achieve anticoagulation while eliminating the need for calcium replacement. This was successfully achieved by including citrate and calcium in all CRRT solutions. Thereby the total calcium concentration was kept constant throughout the extracorporeal circuit while the ionized calcium was kept at levels low enough to avoid clotting. Being a completely new concept, only five patients with acute renal failure were included in a short, prospective, intensely supervised non-randomized pilot study.Systemic electrolyte levels and acid-base parameters were stable and remained within physiological levels. Ionized calcium levels declined slightly initially, but stabilized at 1.1 mmol/l. Plasma citrate concentrations stabilized at around 0.6 mmol/l. All post-filter ionized calcium levels were <0.5 mmol/l, i.e. an anticoagulation effect was reached. All filter pressures were normal indicating no clotting problems, and no visible clotting was observed. No calcium replacement was needed.This pilot study suggests that it is possible to perform regional citrate anticoagulation without the need for separate calcium infusion during CRRT.
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| 8. |
- Bryland, Anna, et al.
(författare)
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Citrate treatment reduces endothelial death and inflammation under hyperglycaemic conditions.
- 2012
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Ingår i: Diabetes & Vascular Disease Research. - : SAGE Publications. - 1752-8984 .- 1479-1641. ; 9:1, s. 42-51
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Tidskriftsartikel (refereegranskat)abstract
- Hyperglycaemia and glucose degradation products (GDPs) are closely associated with oxidative stress and inflammation in diabetic patients, a condition that leads to endothelial dysfunction and cardiovascular problems. We evaluated the effect of citrate and gluconate on glucose- and GDP-induced endothelial inflammation by measuring changes in viability, inflammation and function in primary human umbilical vein endothelial cells (HUVECs). The extent of apoptosis/necrosis was measured by flow cytometry and visualised with confocal microscopy by staining with annexin V or propidium iodide, respectively. Protein kinase C-βII (PKC-βII) activation was evaluated with Western blotting. Incubation with glucose (30 mM) and GDP (50 µM) significantly increased PKC-βII expression, endothelial cell death and inflammation. The addition of citrate decreased hyperglycaemia-induced apoptosis (p = 0.021), necrosis (p = 0.04) and reduced PKC-βII expression (p = 0.021) down to background levels. Citrate improved endothelial function by reducing the inflammatory markers(p = 0.01) and by decreasing neutrophil diapedesis (p = 0.012). These results suggest that citrate may have therapeutic potential by reducing hyperglycaemia-induced endothelial inflammation and abolishing endothelial dysfunction.
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| 9. |
- Bryland, Anna, et al.
(författare)
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Infusion fluids contain harmful glucose degradation products.
- 2010
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Ingår i: Intensive Care Medicine. - : Springer Science and Business Media LLC. - 0342-4642 .- 1432-1238. ; May 4, s. 1213-1220
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: Glucose degradation products (GDPs) are precursors of advanced glycation end products (AGEs) that cause cellular damage and inflammation. We examined the content of GDPs in commercially available glucose-containing infusion fluids and investigated whether GDPs are found in patients' blood. METHODS: The content of GDPs was examined in infusion fluids by high-performance liquid chromatography (HPLC) analysis. To investigate whether GDPs also are found in patients, we included 11 patients who received glucose fluids (standard group) during and after their surgery and 11 control patients receiving buffered saline (control group). Blood samples were analyzed for GDP content and carboxymethyllysine (CML), as a measure of AGE formation. The influence of heat-sterilized fluids on cell viability and cell function upon infection was investigated. RESULTS: All investigated fluids contained high concentrations of GDPs, such as 3-deoxyglucosone (3-DG). Serum concentration of 3-DG increased rapidly by a factor of eight in patients receiving standard therapy. Serum CML levels increased significantly and showed linear correlation with the amount of infused 3-DG. There was no increase in serum 3-DG or CML concentrations in the control group. The concentration of GDPs in most of the tested fluids damaged neutrophils, reducing their cytokine secretion, and inhibited microbial killing. CONCLUSIONS: These findings indicate that normal standard fluid therapy involves unwanted infusion of GDPs. Reduction of the content of GDPs in commonly used infusion fluids may improve cell function, and possibly also organ function, in intensive-care patients.
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| 10. |
- Campos Pacheco, Jesús Enrique, et al.
(författare)
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Inhalable porous particles as dual micro-nano carriers demonstrating efficient lung drug delivery for treatment of tuberculosis
- 2024
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Ingår i: Journal of Controlled Release. - : Elsevier B.V.. - 0168-3659 .- 1873-4995. ; 369, s. 231-250
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Tidskriftsartikel (refereegranskat)abstract
- Inhalation therapy treating severe infectious disease is among the more complex and emerging topics in controlled drug release. Micron-sized carriers are needed to deposit drugs into the lower airways, while nano-sized carriers are of preference for cell targeting. Here, we present a novel and versatile strategy using micron-sized spherical particles with an excellent aerodynamic profile that dissolve in the lung fluid to ultimately generate nanoparticles enabling to enhance both extra- and intra-cellular drug delivery (i.e., dual micro-nano inhalation strategy). The spherical particles are synthesised through the condensation of nano-sized amorphous silicon dioxide resulting in high surface area, disordered mesoporous silica particles (MSPs) with monodispersed size of 2.43 μm. Clofazimine (CLZ), a drug shown to be effective against multidrug-resistant tuberculosis, was encapsulated in the MSPs obtaining a dry powder formulation with high respirable fraction (F.P.F. <5 μm of 50%) without the need of additional excipients. DSC, XRPD, and Nitrogen adsorption-desorption indicate that the drug was fully amorphous when confined in the nano-sized pores (9–10 nm) of the MSPs (shelf-life of 20 months at 4 °C). Once deposited in the lung, the CLZ-MSPs exhibited a dual action. Firstly, the nanoconfinement within the MSPs enabled a drastic dissolution enhancement of CLZ in simulated lung fluid (i.e., 16-fold higher than the free drug), increasing mycobacterial killing than CLZ alone (p = 0.0262) and reaching concentrations above the minimum bactericidal concentration (MBC) against biofilms of M. tuberculosis (i.e., targeting extracellular bacteria). The released CLZ permeated but was highly retained in a Calu-3 respiratory epithelium model, suggesting a high local drug concentration within the lung tissue minimizing risk for systemic side effects. Secondly, the micron-sized drug carriers spontaneously dissolve in simulated lung fluid into nano-sized drug carriers (shown by Nano-FTIR), delivering high CLZ cargo inside macrophages and drastically decreasing the mycobacterial burden inside macrophages (i.e., targeting intracellular bacteria). Safety studies showed neither measurable toxicity on macrophages nor Calu-3 cells, nor impaired epithelial integrity. The dissolved MSPs also did not show haemolytic effect on human erythrocytes. In a nutshell, this study presents a low-cost, stable and non-invasive dried powder formulation based on a dual micro-nano carrier to efficiently deliver drug to the lungs overcoming technological and practical challenges for global healthcare.
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| 11. |
- Chaturvedi, Swasti, et al.
(författare)
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Slit2 Prevents Neutrophil Recruitment and Renal Ischemia-Reperfusion Injury : english
- 2013
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Ingår i: Journal of the American Society of Nephrology. - 1046-6673. ; 24:8, s. 1274-1287
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils recruited to the postischemic kidney contribute to the pathogenesis of ischemia-reperfusion injury (IRI), which is the most common cause of renal failure among hospitalized patients. The Slit family of secreted proteins inhibits chemotaxis of leukocytes by preventing activation of Rho-family GTPases, suggesting that members of this family might modulate the recruitment of neutrophils and the resulting IRI. Here, in static and microfluidic shear assays, Slit2 inhibited multiple steps required for the infiltration of neutrophils into tissue. Specifically, Slit2 blocked the capture and firm adhesion of human neutrophils to inflamed vascular endothelial barriers as well as their subsequent transmigration. To examine whether these observations were relevant to renal IRI, we administered Slit2 to mice before bilateral clamping of the renal pedicles. Assessed at 18 hours after reperfusion, Slit2 significantly inhibited renal tubular necrosis, neutrophil and macrophage infiltration, and rise in plasma creatinine. In vitro, Slit2 did not impair the protective functions of neutrophils, including phagocytosis and superoxide production, and did not inhibit neutrophils from killing the extracellular pathogen Staphylococcus aureus. In vivo, administration of Slit2 did not attenuate neutrophil recruitment or bacterial clearance in mice with ascending Escherichia coli urinary tract infections and did not increase the bacterial load in the livers of mice infected with the intracellular pathogen Listeria monocytogenes. Collectively, these results suggest that Slit2 may hold promise as a strategy to combat renal IRI without compromising the protective innate immune response.
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| 12. |
- Demirel, Isak, 1987-
(författare)
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Uropathogenic Esherichia coli, multidrug-resistance and induction of host defense mechanisms
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Uropathogenic Escherichia coli (UPEC) is the primary cause of urinary tract infection (UTI), which is one of the most common infections in humans. UPEC strains have acquired successful strategies to subvert the host defense and antibiotics to persist in the urinary tract. The main aim of this thesis was to investigate the host defense mechanisms during a UPEC infection in vitro.The results showed that SOCS3, a key regulator of the immune system, was increased in bladder epithelial cells in response to a UPEC infection. In addition, UPEC decreased the phosphorylation of the SOCS3 regulated transcription factor STAT3. Nitric oxide (NO), a host-derived antimicrobial factor was shown to increase the release of IL-6 from renal epithelial cells alone or in combination with UPEC. The induction of IL-6 was mediated by ERK1/2 and p38 MAPK signaling and NO was also shown to attenuate UPEC-induced IL-6 mRNA degradation. Furthermore, extended-spectrum beta-lactamase (ESBL)-producing UPEC isolates were shown to induce higher PMN migration and ROS-production, but lower cytokine secretion from renal epithelial cells than susceptible isolates. Ineffective ceftibuten treatment of ESBL isolates induced bacterial filamentation associated with an increased release of ATP and LPS, with a subsequent enhancement of the ESBL evoked host response.Taken together, the findings show that UPEC can induce SOCS3, a suppressor of host responses and that NO can regulate proinflammatory mediators. In addition, the data suggest that there are differences between ESBL- and non-ESBL-producing isolates ability to evoke a host response. Exposing resistant isolates to ineffective antibiotics was shown to alter the evoked host response.
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| 13. |
- Frendeus, Björn, et al.
(författare)
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Interleukin 8 receptor deficiency confers susceptibility to acute experimental pyelonephritis and may have a human counterpart
- 2000
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Ingår i: Journal of Experimental Medicine. - 1540-9538. ; 192:6, s. 881-890
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophils migrate to infected mucosal sites that they protect against invading pathogens. Their interaction with the epithelial barrier is controlled by CXC chemokines and by their receptors. This study examined the change in susceptibility to urinary tract infection (UTI) after deletion of the murine interleukin 8 receptor homologue (mIL-8Rh). Experimental UTIs in control mice stimulated an epithelial chemokine response and increased chemokine receptor expression. Neutrophils migrated through the tissues to the epithelial barrier that they crossed into the lumen, and the mice developed pyuria. In mIL-8Rh knockout (KO) mice, the chemokine response was intact, but the epithelial cells failed to express IL-8R, and neutrophils accumulated in the tissues. The KO mice were unable to clear bacteria from kidneys and bladders and developed bacteremia and symptoms of systemic disease, but control mice were fully resistant to infection. The experimental UTI model demonstrated that IL-8R-dependent mechanisms control the urinary tract defense, and that neutrophils are essential host effector cells. Patients prone to acute pyelonephritis also showed low CXC chemokine receptor 1 expression compared with age-matched controls, suggesting that chemokine receptor expression may also influence the susceptibility to UTIs in humans. The results provide a first molecular clue to disease susceptibility of patients prone to acute pyelonephritis.
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| 14. |
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| 15. |
- Godaly, Gabriela, et al.
(författare)
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Fimbrial lectins influence the chemokine repertoire in the urinary tract mucosa.
- 2007
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Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 71:8, s. 778-786
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Tidskriftsartikel (refereegranskat)abstract
- The defense against mucosal infections relies on chemokines that recruit inflammatory cells to the mucosa. This study examined if the chemokine response to uro-pathogenic Escherichia coli is influenced by fimbrial expression. The CXC (CXCL1, CXCL5, CXCL8, CXCL9, CXCL10) and CC chemokines (CCL2, CCL3, CCL5) were quantified after in vitro infection of uro-epithelial cells with a fimbriated E. coli pyelonephritis isolate, or with P or type 1 fimbriated transformants of an avirulent E. coli K-12 strain. The response profile was shown to vary with the fimbrial type. Type 1 fimbriated E. coli elicited mainly CXCL1 and CXCL8, whereas P fimbriated E. coli stimulated CCL2 and CCL5 and class II were more potent chemokine inducers than class III P fimbriae. Chemokines were also quantified in urine samples from 73 patients with febrile urinary tract infection, and analyzed as a function of disease severity and fimbrial expression by the strain infecting each patient. A complex CXC and CC chemokine response was detected in patient urine, with a significant influence of the fimbrial type. The results show that virulence factors like fimbriae may modify the mucosal chemokine response. This mechanism may allow the host to adjust the inflammatory cell infiltrate to fit the infecting strain.
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| 16. |
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| 17. |
- Godaly, Gabriela, et al.
(författare)
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Innate immunity and genetic determinants of urinary tract infection susceptibility.
- 2015
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Ingår i: Current Opinion in Infectious Diseases. - 1473-6527. ; 28:1, s. 88-96
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Forskningsöversikt (refereegranskat)abstract
- Urinary tract infections (UTIs) are common, dangerous and interesting. Susceptible individuals experience multiple, often clustered episodes, and in a subset of patients, infections progress to acute pyelonephritis (APN), sometimes accompanied by uro-sepsis. Others develop asymptomatic bacteriuria (ABU). Here, we review the molecular basis for these differences, with the intention to distinguish exaggerated host responses that drive disease from attenuated responses that favour protection and to highlight the genetic basis for these extremes, based on knock-out mice and clinical studies.
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| 18. |
- Godaly, Gabriela
(författare)
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Mechanisms of Escherichia coli induced transepithelial neutrophil migration
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mucosal infections trigger an inflammatory response that includes the secretion of cytokines and the recruitment of neutrophils to the infected site. This thesis describes studies examining the molecular mechanisms of neutrophil migration to sites of mucosal bacterial infection. Escherichia coli (E. coli) infection of epithelial cell layers stimulates chemokine secretion and chemokine receptor expression. Human epithelial cells produced an array of CXC chemokines (e.g., IL-8, GRO, ENA-78, IP-10, MIG) and CC chemokines (e.g., MCP-1, MIP, RANTES) in response to bacterial infection. The chemokine repertoire was shown to be influenced by the fimbrial expression of the infecting strain. Furthermore, E. coli infection increased the expression of chemokine receptors (CXCR1 and CXCR2) on epithelial cells. IL-8 was found to be the major chemoattractant involved in neutrophil migration across infected epithelial cell layers. Transuroepithelial neutrophil migration was also shown to be depending on the level of CXCR1 expression on neutrophils and epithelial cell layers. The in vitro observations were confirmed in an experimental UTI model. Recombinant P or type 1 fimbriated E. coli stimulated chemokine responses and neutrophil recruitment more efficiently than the non-fimbriated controls. The relevance of IL-8 receptor expression was confirmed in vivo using IL-8 receptor knock-out (mIL-8Rh KO) mice. E. coli infection of mIL-8Rh KO mice caused the neutrophils to leave the blood vessels but they were unable to cross the epithelium and accumulated in the tissues. Bacterial clearance was impaired and tissues were destroyed. Subsequent human studies showed a decrease in CXCR1 expression on neutrophils from patients prone to acute pyelonephritis. These results provide a first molecular clue to the host defect in patients prone to acute pyelonephritis.
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| 19. |
- Godaly, Gabriela, et al.
(författare)
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Mycobacterium bovis bacille Calmette Guerin infection of human neutrophils induces CXCL8 secretion by MyD88-dependent TLR2 and TLR4 activation
- 2005
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Ingår i: Cellular Microbiology. - : Hindawi Limited. - 1462-5814 .- 1462-5822. ; 7:4, s. 591-601
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Tidskriftsartikel (refereegranskat)abstract
- To investigate the potential role of neutrophils in initiation of immune responses to mycobacteria, we have characterized the response of human neutrophils to infection with Mycobacterium bovis bacille Calmette Guerin, the BCG vaccine. BCG induced transcription and secretion of the chemokine CXCL8, by signalling through Toll-like receptors TLR2 and TLR4, in conjunction with the adaptor protein myeloid differentiation factor 88 (MyD88). Blocking of responses with antibodies revealed a difference in the kinetics of signalling through the different TLRs. Anti-TLR2 antibody blocked the early phase of CXCL8 and MyD88 induction. Anti-TLR4 antibody blocked the late phase of induction occurring 2 h after infection. The existence of a TLR/MyD88 pathway for recognition and response to mycobacterial ligands provides neutrophils with the ability to drive the recruitment and activation of inflammatory cells during the early phase of mycobacterial infection and immunization.
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| 20. |
- Godaly, Gabriela, et al.
(författare)
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Neutrophil recruitment, chemokine receptors, and resistance to mucosal infection
- 2001
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Ingår i: Journal of Leukocyte Biology. - 1938-3673. ; 69:6, s. 899-906
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophil migration to infected mucosal sites involves a series of complex interactions with molecules in the lamina propria and at the epithelial barrier. Much attention has focussed on the vascular compartment and endothelial cells, but less is known about the molecular determinants of neutrophil behavior in the periphery. We have studied urinary tract infections (UTIs) to determine the events that initiate neutrophil recruitment and interactions of the recruited neutrophils with the mucosal barrier. Bacteria activate a chemokine response in uroepithelial cells, and the chemokine repertoire depends on the bacterial virulence factors and on the specific signaling pathways that they activate. In addition, epithelial chemokine receptor expression is enhanced. Interleukin (IL)-8 and CXCR1 direct neutrophil migration across the epithelial barrier into the lumen. Indeed, mIL-8Rh knockout mice showed impaired transepithelial neutrophil migration, with tissue accumulation of neutrophils, and these mice developed renal scarring. They had a defective antibacterial defense and developed acute pyelonephritis with bacteremia. Low CXCR1 expression was also detected in children with acute pyelonephritis. These results demonstrate that chemokines and chemokine receptors are essential to orchestrate a functional antimicrobial defense of the urinary tract mucosa. Mutational inactivation of the IL-8R caused both acute disease and chronic tissue damage.
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| 21. |
- Godaly, Gabriela
(författare)
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Pedagogisk utvecklingsplan för kurs i Patobiologi 1, termin 4, Läkarprogrammet
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Jag har analyserat grundkursen i Patobiologi på termin 4 inom Läkarprogrammet som grund för pedagogisk utvecklingsplan. Kursen ges i både Lund (LÄLA42) och Malmö (LÄMA42) och har gemensam kursplan, identiska mål och kriterier för examination. Kursens syfte är att ge studenterna goda och relevanta kunskaper samt färdigheter i patobiologi, men ger även undervisning i laboratoriemedicinsk diagnostik samt farmakologisk behandling. Undervisning har PBL-fall som grund. Denna understöds av föreläsningar, laborationer, demonstrationer, obduktioner, seminarier, skriftliga uppgifter och artikelläsning. Examinationen sker med skriftlig tentamen (21 hp) samt en godkänd kursportfölj (7,5 hp). Studenterna i Lund och Malmö har samma tentamen, men undervisningen planeras av separata kursledningar i Malmö och Lund. Dessa träffas och samordnar undervisningen så att innehållet skall vara likvärdigt. Jag har analyserat Lunda-kursen och Lena Gustavsson har undersökt Malmö-kursen. Därefter jämförde vi gemensamt kurserna med avseende på upplägg och innehåll och fann dem båda väl samordnade, men med några mindre skillnader. Vi undersökte även om det går att dela upp tentamen då detta efterfrågades av flera studenter. Då vi anser att det är viktigt att säkerställa att undervisningen har samma innehåll och kvalité i Malmö och Lund har vi skrivit en gemensam utvecklingsplan.
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| 22. |
- Godaly, Gabriela, et al.
(författare)
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Phoxilium® reduces hypophosphataemia and magnesium supplementation during continuous renal replacement therapy
- 2016
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Ingår i: Clinical Kidney Journal. - : Oxford University Press (OUP). - 2048-8505 .- 2048-8513. ; 9:2, s. 205-210
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Tidskriftsartikel (refereegranskat)abstract
- Background Although associated with severe clinical complications, phosphate remains a neglected ion. Additionally, phosphate balance during continuous renal replacement therapy (CRRT) is complex and multifunctional. The present retrospective study investigated the effects of phosphate-containing CRRT fluid on phosphate homeostasis. Methods We retrospectively analysed 112 patients treated with CRRT at Skane University Hospital, Sweden. The control group was treated with Hemosol® B0 (no phosphate; n = 36) as dialysis and replacement fluid, while the study group received Phoxilium® (phosphate; n = 76) as dialysis fluid and Hemosol® B0 as replacement fluid. Results Hypophosphataemia (
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| 23. |
- Godaly, Gabriela, et al.
(författare)
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Role of epithelial interleukin-8 (IL-8) and neutrophil IL-8 receptor A in Escherichia coli-induced transuroepithelial neutrophil migration
- 1997
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Ingår i: Infection and Immunity. - 1098-5522. ; 65:8, s. 3451-3456
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Tidskriftsartikel (refereegranskat)abstract
- Escherichia coli stimulates neutrophil migration across human uroepithelial cell layers. This study investigated the role of the neutrophil chemokine interleukin-8 (IL-8) in this process. E. coli and IL-1alpha stimulated urinary tract epithelial layers to secrete IL-8 and induced transepithelial neutrophil migration. Anti-IL-8 antibody reduced neutrophil migration across epithelial cell layers, indicating a central role for this chemokine in the migration process. Furthermore, addition of recombinant IL-8 to unstimulated cell layers was sufficient to induce migration. The IL-8 dependence of neutrophil migration was maintained after removal of soluble IL-8 by washing of the cell layers. Flow cytometry analysis with fluorescein isothiocyanate-labelled IL-8 confirmed IL-8's ability to bind to the epithelial cell surface. Indirect immunofluorescence with confocal laser scanning microscopy showed that IL-8 associated with the epithelial cell layers. Prior incubation of neutrophils with antibodies to IL-8 receptor A (IL-8RA) reduced neutrophil migration. Anti-IL-8 RB antibody had no effect on neutrophil migration. These results demonstrate that IL-8 plays a key role in E. coli- or IL-1alpha-induced transuroepithelial migration and suggest that epithelial cell-produced IL-8 interacts with IL-8RA on the neutrophil surface.
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| 24. |
- Godaly, Gabriela, et al.
(författare)
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Role of fimbriae-mediated adherence for neutrophil migration across Escherichia coli-infected epithelial cell layers
- 1998
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Ingår i: Molecular Microbiology. - : Wiley. - 1365-2958 .- 0950-382X. ; 30:4, s. 725-735
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the role of P and type 1 fimbriae for neutrophil migration across Escherichia coli-infected uroepithelial cell layers in vitro and for neutrophil recruitment to the urinary tract in vivo. Recombinant E. coli K-12 strains differing in P or type 1 fimbrial expression were used to infect confluent epithelial layers on the underside of transwell inserts. Neutrophils were added to the upper well, and their passage across the epithelial cell layers was quantified. Infection with the P- and type 1-fimbriated recombinant E. coli strains stimulated neutrophil migration to the same extent as a fully virulent clinical E. coli isolate, but the isogenic non-fimbriated vector control strains had no stimulatory effect. The enhancement of neutrophil migration was adhesion dependent; it was inhibited by soluble receptor analogues blocking the binding of P fimbriae to the globoseries of glycosphingolipids or of type 1 fimbriae to mannosylated glycoprotein receptors. P- and type 1-fimbriated E. coli triggered higher interleukin (IL) 8 secretion and expression of functional IL-8 receptors than non-fimbriated controls, and the increase in neutrophil migration across infected cell layers was inhibited by anti-IL-8 antibodies. In a mouse infection model, P- or type 1-fimbriated E. coli stimulated higher chemokine (MIP-2) and neutrophil responses than the non-fimbriated vector controls. The results demonstrated that transformation with the pap or fim DNA sequences is sufficient to convert an E. coli K-12 strain to a host response inducer, and that fimbriation enhances neutrophil recruitment in vitro and in vivo. Epithelial chemokine production provides a molecular link between the fimbriated bacteria that adhere to epithelial cells and tissue inflammation.
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| 25. |
- Godaly, Gabriela, et al.
(författare)
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Transepithelial neutrophil migration is CXCR1 dependent in vitro and is defective in IL-8 receptor knockout mice
- 2000
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Ingår i: Journal of Immunology. - 1550-6606. ; 165:9, s. 5287-5294
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Tidskriftsartikel (refereegranskat)abstract
- Neutrophil migration across infected mucosal surfaces is chemokine dependent, but the role of chemokine receptors has not been investigated. In this study, chemokine receptors were shown to be expressed by epithelial cells lining the urinary tract, and to play an essential role for neutrophil migration across the mucosal barrier. Uroepithelial CXCR1 and CXCR2 expression was detected in human urinary tract biopsies, and in vitro infection of human uroepithelial cell lines caused a dramatic increase in both receptors. As a consequence, there was higher binding of IL-8 to the cells and the IL-8-dependent neutrophil migration across the infected epithelial cell layers was enhanced. Abs to IL-8 or to the CXCR1 receptor inhibited this increase by 60% (p<0.004), but anti-CXCR2 Abs had no effect, suggesting that CXCR1 was the more essential receptor in this process. Similar observations were made in the mouse urinary tract, where experimental infection stimulated epithelial expression of the murine IL-8 receptor, followed by a rapid flux of neutrophils into the lumen. IL-8 receptor knockout mice, in contrast, failed to express the receptor, their neutrophils were unable to cross the epithelial barrier, and accumulated in massive numbers in the tissues. These results demonstrate that epithelial cells express CXC receptors and that infection increases receptor expression. Furthermore, we show that CXCR1 is required for neutrophil migration across infected epithelial cell layers in vitro, and that the murine IL-8 receptor is needed for neutrophils to cross the infected mucosa of the urinary tract in vivo.
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| 26. |
- Godaly, Gabriela, et al.
(författare)
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Urinary Tract Infection Molecular Mechanisms and Clinical Translation.
- 2016
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Ingår i: Pathogens. - : MDPI AG. - 2076-0817. ; 5:1
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Forskningsöversikt (refereegranskat)abstract
- Rapid developments in infection biology create new and exciting options for individualized diagnostics and therapy. Such new practices are needed to improve patient survival and reduce morbidity. Molecular determinants of host resistance to infection are being characterized, making it possible to identify susceptible individuals and to predict their risk for future morbidity. Immunotherapy is emerging as a new strategy to treat infections worldwide and controlled boosting of the host immune defense represents an important therapeutic alternative to antibiotics. In proof of concept studies, we have demonstrated that this approach is feasible. The long-term goal is not just to remove the pathogens but to also develop technologies that restore resistance to infection in disease-prone patients and devise personalized therapeutic interventions. Here, we discuss some approaches to reaching these goals, in patients with urinary tract infection (UTI). We describe critical host signaling pathways that define symptoms and pathology and the genetic control of innate immune responses that balance protection against tissue damage. For some of these genes, human relevance has been documented in clinical studies, identifying them as potential targets for immune-modulatory therapies, as a complement to antibiotics.
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| 27. |
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| 28. |
- Godaly, Gabriela, et al.
(författare)
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Urinary tract infections revisited.
- 2007
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Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 71:8, s. 721-723
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Tidskriftsartikel (refereegranskat)abstract
- Urinary tract infections (UTIs) remain a significant clinical problem, despite antibiotic treatment and surgical correction of reflux and malformations. Here we propose that novel molecular tools may be applied to modernize and individualize the diagnosis and therapy of UTI. Determinants of bacterial virulence and host resistance are relatively well understood at the molecular level, and technology for their detection is within reach.
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| 29. |
- Grønberg, Christina, et al.
(författare)
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Structure and ion-release mechanism of P IB-4-type ATPases
- 2022
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Ingår i: eLife. - : eLife Sciences Publications Ltd. - 2050-084X.
-
Tidskriftsartikel (refereegranskat)abstract
- Abstract Transition metals, such as zinc, are essential micronutrients in all organisms, but alsohighly toxic in excessive amounts. Heavy-metal transporting P-type (PIB) ATPases are crucial forhomeostasis, conferring cellular detoxification and redistribution through transport of these ionsacross cellular membranes. No structural information is available for the PIB-4-ATPases, the subclasswith the broadest cargo scope, and hence even their topology remains elusive. Here, we presentstructures and complementary functional analyses of an archetypal PIB-4-ATPase, sCoaT fromSulfitobacter sp. NAS14-1. The data disclose the architecture, devoid of classical so-called heavy-metal-binding domains (HMBDs), and provide fundamentally new insights into the mechanism anddiversity of heavy-metal transporters. We reveal several novel P-type ATPase features, includinga dual role in heavy-metal release and as an internal counter ion of an invariant histidine. We alsoestablish that the turnover of PIB-ATPases is potassium independent, contrasting to many otherP-type ATPases. Combined with new inhibitory compounds, our results open up for efforts in forexample drug discovery, since PIB-4-ATPases function as virulence factors in many pathogens.
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| 30. |
- Hang, Long, et al.
(författare)
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Interleukin-8 receptor knockout mice have subepithelial neutrophil entrapment and renal scarring following acute pyelonephritis
- 2000
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 182:6, s. 1738-1748
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin (IL)-8 receptor knockout (KO) mice were shown to have a dysfunctional neutrophil response to urinary tract infection and to develop renal scarring. Intravesical Escherichia coli infection stimulated epithelial chemokine secretion and IL-8 receptor expression in control mice. Neutrophils migrated through the tissues and crossed the epithelial barrier into the urinary tract lumen. In murine IL-8 receptor homologue (mIL-8Rh) KO mice, infection triggered a chemokine response, and neutrophils were recruited but failed to traverse the mucosal barrier and accumulated under the epithelium. After 7 days, control mice were healthy, and infection was cleared, but mIL-8Rh KO mice had swollen kidneys, with neutrophil abscesses and high numbers of bacteria. After 35 days, they developed kidney pathology and renal scarring. The results demonstrate that chemokine receptors drive transepithelial neutrophil migration. In their absence, the neutrophils are trapped, and the tissues are destroyed. This molecular deficiency may determine the progression from acute pyelonephritis to renal scarring.
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| 31. |
- Haraoka, Masashi, et al.
(författare)
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Neutrophil recruitment and resistance to urinary tract infection
- 1999
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Ingår i: Journal of Infectious Diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 180:4, s. 1220-1229
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Tidskriftsartikel (refereegranskat)abstract
- This study examined the role of neutrophil leukocytes for the antibacterial defense at mucosal infection sites. Urinary tract infection (UTI) was established by injection into the bladder lumen of Escherichia coli 1177, a fully virulent clinical isolate. Infection of C3H/HeN (lpsn, lpsn) mice recruited neutrophils into the urinary tract, and bacteria were cleared from kidneys and bladders. The neutrophil response was absent in C3H/HeJ (lpsd, lpsd) mice, and bacteria persisted in the tissues. Peripheral neutrophil depletion of C3H/HeN mice was subsequently achieved by pretreatment with the granulocyte-specific antibody RB6-8C5. The E. coli-induced neutrophil recruitment was inhibited, as shown by immunohistochemistry and tissue myeloperoxidase quantitation. As a consequence, bacterial clearance from kidneys and bladders was drastically impaired. Antibody treatment of C3H/HeJ mice had only a marginal effect. The results show that neutrophils are essential for bacterial clearance from the urinary tract and that the neutrophil recruitment deficiency in C3H/HeJ mice explains their susceptibility to gram-negative UTI.
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| 32. |
- Håkansson, Gisela, et al.
(författare)
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Epithelial G protein-coupled receptor kinases regulate the initial inflammatory response during mycobacterial infection.
- 2013
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Ingår i: Immunobiology. - : Elsevier BV. - 1878-3279 .- 0171-2985. ; 218:7, s. 984-994
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Tidskriftsartikel (refereegranskat)abstract
- The interaction between mycobacteria and epithelium is unexplored, but may determine the outcome of the infection. We have analyzed the role of two G protein-coupled receptors, CXCR1 and CXCR2 that are important regulators of many pulmonary diseases. We found that mycobacteria significantly increased the expression of both CXCR1 and CXCR2 on alveolar epithelial cells and both receptors were found to be important for neutrophil diapedesis across primary endothelial cells towards infected mucosa. Mycobacteria, lipoarabinomannan or 19-kDa glycolipoprotein up-regulated the inhibitory G protein-coupled receptor kinase (GRK)2, while GRK3 was less affected. Mycobacteria-induced GRK2 up-regulation decreased chemokine transcription and secretion thereby affecting the neutrophil recruitment to infected mucosa. These events were completely abolished by blocking these receptors prior to infection as the blocking increased epithelial immune responses. We have identified novel interactions occurring in the initial phase of mycobacterial infections by which mycobacterial manipulate epithelial inflammatory responses.
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| 33. |
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| 34. |
- Lutay, Nataliya, et al.
(författare)
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Mycobacteria Bypass Mucosal NF-kB Signalling to Induce an Epithelial Anti-Inflammatory IL-22 and IL-10 Response.
- 2014
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- The mechanisms by which mycobacteria subvert the inflammatory defence to establish chronic infection remain an unresolved question in the pathogenesis of tuberculosis. Using primary epithelial cells, we have analysed mycobacteria induced epithelial signalling pathways from activation of TLRs to cytokine secretion. Mycobacterium bovis bacilli Calmette-Guerin induced phosphorylation of glycogen synthase kinase (GSK)3 by PI3K-Akt in the signalling pathway downstream of TLR2 and TLR4. Mycobacteria did not supress NF-κB by activating the peroxisome proliferator-activated receptor γ. Instead the pro-inflammatory NF-κB was bypassed by mycobacteria induced GSK3 inhibition that promoted the anti-inflammatory transcription factor CREB. Mycobacterial infection did not thus induce mucosal pro-inflammatory response as measured by TNFα and IFNγ secretion, but led to an anti-inflammatory IL-10 and IL-22 production. Apart from CREB, MAP3Ks p38 and ERK1/2 activated the transcription factor AP-1 leading to IL-6 production. Interestingly, blocking of TLR4 before infection decreased epithelial IL-6 secretion, but increased the CREB-activated IL-10 production. Our data indicate that mycobacteria supress epithelial pro-inflammatory production by supressing NF-κB activation thereby shifting the infection towards an anti-inflammatory state. This balance between the host immune response and the pathogen could determine the outcome of infection.
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| 35. |
- Mohanty, Soumitra, et al.
(författare)
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A mycobacterial phosphoribosyltransferase promotes bacillary survival by inhibiting oxidative stress and autophagy pathways in macrophages and zebrafish.
- 2015
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Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 290:21, s. 13321-13343
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Tidskriftsartikel (refereegranskat)abstract
- Mycobacterium tuberculosis (Mtb) employs various strategies to modulate host immune responses to facilitate its persistence in macrophages. The Mtb cell wall contains numerous glycoproteins with unknown role in pathogenesis. Here, by using concavalinA and LC-MS analysis we identified a novel mannosylated glycoprotein phosphoribosyl- transferase, encoded by the Rv3242c, from Mtb cell walls. Homology modeling, bioinformatic analyses and assay of phosphoribosyltransferase activity measurement in Mycobacterium smegmatis expressing recombinant Rv3242c (MsmRv3242c) confirmed the mass spectrometry data. Using Mycobacterium marinum-zebrafish and the surrogate MsmRv3242c infection models, we proved that phosphoribosyltransferase is involved in mycobacterial virulence. Histological and infection assays showed that M. marinum mimG mutant, an Rv3242c orthologue in a pathogenic M. marinum strain, was strongly attenuated in adult zebrafish and also survived less in macrophages. In contrast, infection with wild-type and the complemented ∆mimG:Rv3242c M. marinum strains showed prominent pathological features such as severe emaciation, skin lesions, hemorrhaging, and more zebrafish death. Similarly, recombinant MsmRv3242c bacteria showed increased invasion in non-phagocytic epithelial cells and longer intracellular survival in macrophages as compared to wild-type and vector control M. smegmatis strains. Further mechanistic studies revealed that the Rv3242c and mimG mediated enhancement of intramacrophagic survival was due to inhibition of autophagy, reactive oxygen species and reduced activities of superoxide dismutase and catalase enzymes. Infection with MsmRv3242c also activated the MAPK pathway, NF-κB and inflammatory cytokines. In summary, we show that a novel mycobacterial mannosylated phosphoribosyltransferase acts as a virulence and immunomodulatory factors, suggesting that it may constitute a novel target for antimycobacterial drugs.
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| 36. |
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| 37. |
- Ragnarsdottir, Bryndis, et al.
(författare)
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TLR- and CXCR1-dependent innate immunity: insights into the genetics of urinary tract infections.
- 2008
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Ingår i: European Journal of Clinical Investigation. - : Wiley. - 0014-2972 .- 1365-2362. ; 38 Suppl 2, s. 12-20
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Forskningsöversikt (refereegranskat)abstract
- The susceptibility to urinary tract infection (UTI) is controlled by the innate immune response and Toll like receptors (TLRs) are the sentinels of this response. If productive, TLR4 signalling may initiate the symptomatic disease process. In the absence of TLR4 signalling the infected host instead develops an asymptomatic carrier state. The activation of mucosal TLR4 is also influenced by the properties of the infecting strain, and pathogens use their virulence factors to trigger 'pathogen-specific' TLR4 responses in the urinary tract but do not respond to the asymptomatic carrier strains in patients with asymptomatic bacteriuria (ABU). The TLR4 dependence has been demonstrated in mice and the relevance of low TLR4 function for protection for human disease was recently confirmed in children with asymptomatic bacteriuria, who expressed less TLR4 than age matched controls. Functional chemokines and functional chemokine receptors are crucial for neutrophil recruitment, and for the neutrophil dependent bacterial clearance. Interleukin (IL)-8 receptor deficient mice develop acute septic infections and chronic tissue damage, due to aberrant neutrophil function. This mechanism is relevant for human UTI as pyelonephritis prone children express low levels of the human CXCL8 (Il-8) receptor, CXC chemokine receptor 1 (CXCR1) and often have heterozygous CXCR1 polymorphisms. This review illustrates how intimately the innate response and the susceptibility to UTI are linked and sophisticated recognition mechanisms that rely on microbial virulence and on host TLR4 and CXCR1 signalling.
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| 38. |
- Rao, Komal Umashankar, et al.
(författare)
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A broad spectrum anti-bacterial peptide with an adjunct potential for tuberculosis chemotherapy
- 2021
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 11:1
-
Tidskriftsartikel (refereegranskat)abstract
- Alternative ways to prevent and treat infectious diseases are needed. Previously, we identified a fungal peptide, NZX, that was comparable to rifampicin in lowering M. tuberculosis load in a murine tuberculosis (TB) infection model. Here we assessed the potential synergy between this cationic host defence peptide (CHDP) and the current TB drugs and analysed its pharmacokinetics. We found additive effect of this peptide with isoniazid and ethambutol and confirmed these results with ethambutol in a murine TB-model. In vivo, the peptide remained stable in circulation and preserved lung structure better than ethambutol alone. Antibiotic resistance studies did not induce mutants with reduced susceptibility to the peptide. We further observed that this peptide was effective against nontuberculous mycobacteria (NTM), such as M. avium and M. abscessus, and several Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. In conclusion, the presented data supports a role for this CHDP in the treatment of drug resistant organisms.
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| 39. |
- Rao, Komal Umashankar, et al.
(författare)
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Mechanisms of a Mycobacterium tuberculosis Active Peptide
- 2023
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Ingår i: Pharmaceutics. - : MDPI AG. - 1999-4923. ; 15:2
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Tidskriftsartikel (refereegranskat)abstract
- Multidrug-resistant tuberculosis (MDR) continues to pose a threat to public health. Previously, we identified a cationic host defense peptide with activity against Mycobacterium tuberculosis in vivo and with a bactericidal effect against MDR M. tuberculosis at therapeutic concentrations. To understand the mechanisms of this peptide, we investigated its interactions with live M. tuberculosis and liposomes as a model. Peptide interactions with M. tuberculosis inner membranes induced tube-shaped membranous structures and massive vesicle formation, thus leading to bubbling cell death and ghost cell formation. Liposomal studies revealed that peptide insertion into inner membranes induced changes in the peptides’ secondary structure and that the membranes were pulled such that they aggregated without permeabilization, suggesting that the peptide has a strong inner membrane affinity. Finally, the peptide targeted essential proteins in M. tuberculosis, such as 60 kDa chaperonins and elongation factor Tu, that are involved in mycolic acid synthesis and protein folding, which had an impact on bacterial proliferation. The observed multifaceted targeting provides additional support for the therapeutic potential of this peptide.
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| 40. |
- Rosenblad, Therese, et al.
(författare)
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Genetic determinants of renal scarring in children with febrile UTI
- 2024
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Ingår i: PEDIATRIC NEPHROLOGY. - 0931-041X .- 1432-198X.
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Tidskriftsartikel (refereegranskat)abstract
- Background Febrile urinary tract infections (UTIs) are among the most severe bacterial infections in infants, in which a subset of patients develops complications. Identifying infants at risk of recurrent infections or kidney damage based on clinical signs is challenging. Previous observations suggest that genetic factors influence UTI outcomes and could serve as predictors of disease severity. In this study, we conducted a nationwide survey of infant genotypes to develop a strategy for infection management based on individual genetic risk. Our aims were to identify genetic susceptibility variants for renal scarring (RS) and genetic host factors predisposing to dilating vesicoureteral reflux (VUR) and recurrent UTIs.Methods To assess genetic susceptibility, we collected and analyzed DNA from blood using exome genotyping. Disease-associated genetic variants were identified through bioinformatics analysis, including allelic frequency tests and odds ratio calculations. Kidney involvement was defined using dimercaptosuccinic acid (DMSA) scintigraphy.Results In this investigation, a cohort comprising 1087 infants presenting with their first episode of febrile UTI was included. Among this cohort, a subset of 137 infants who underwent DMSA scanning was subjected to gene association analysis. Remarkable genetic distinctions were observed between patients with RS and those exhibiting resolved kidney involvement. Notably, the genetic signature indicative of renal scarring prominently featured mitochondrial genes.Conclusions In this nationwide study of genetic susceptibility to RS after febrile UTIs in infancy, we identified a profile dominated by mitochondrial polymorphisms. This profile can serve as a predictor of future complications, including RS and recurrent UTIs.Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information
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| 41. |
- Svanborg, Catharina, et al.
(författare)
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Adhesion, signal transduction and mucosal inflammation
- 2002
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Ingår i: Bacterial Adhesion to Host Tissues. - Cambridge : Cambridge University Press. - 9780521801072 - 0521801079 ; , s. 223-246
-
Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 42. |
- Svanborg, Catharina, et al.
(författare)
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Bacterial virulence in urinary tract infection
- 1997
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Ingår i: Infectious Disease Clinics of North America. - 0891-5520. ; 11:3, s. 513-529
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Tidskriftsartikel (refereegranskat)abstract
- Bacteriuria is associated with acute disease conditions of varying severity.48 and 62 Consequently, the definition of bacterial virulence for the urinary tract depends on the end-point chosen. Acute pyelonephritis is characterized by fever, flank pain, and general malaise. Laboratory findings include pyuria (leukocytes in the urine), elevated acute phase reactants in serum (C reactive protein [CRP], erythrocyte sedimentation rate [ESR]), elevated levels of cytokines in serum and urine, and later increased levels of antibacterial IgA antibodies in urine and serum. Cystitis is characterized by dysuria, urgency, frequency of urination, and sometimes suprapubic pain. Acute cystitis should not be accompanied by acute phase reactants or cytokines in the serum, however, there is pyuria, and IL-6 and IL-8 levels in urine may be elevated. Asymptomatic bacteriuria (ABU) is commonly detected at screening because it is not accompanied by any of the symptoms seen for acute pyelonephritis and acute cystitis. The laboratory findings vary. The patients may have low level cytokine responses and leukocytes in urine, or they may have no host response to infection.
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| 43. |
- Svanborg, Catharina, et al.
(författare)
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Cytokine responses during mucosal infections: role in disease pathogenesis and host defence
- 1999
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Ingår i: Current Opinion in Microbiology. - 1879-0364. ; 2:1, s. 99-103
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Tidskriftsartikel (refereegranskat)abstract
- Mucosal pathogens use diverse and highly specific molecular mechanisms to activate mucosal inflammation. It may even be argued that their virulence depends on the inflammatory response that they induce. Some bacteria target epithelial cells and trigger them to produce inflammatory mediators but others cross the mucosa and activate macrophages or dendritic cells. Although systemic release of inflammatory mediators causes many symptoms and signs of infection, local chemokine production leads to the recruitment of inflammatory cells and lymphocytes that participate directly in the clearance of bacteria from mucosal sites. In this way, mucosal inflammation is a two-edged sword responsible for disease associated tissue destruction and crucial for the antimicrobial defence. Understanding of these pathways should create tools to enhance the defence and interfere with disease.
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| 44. |
- Svanborg, Catharina, et al.
(författare)
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The 'innate' host response protects and damages the infected urinary tract
- 2001
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Ingår i: Annals of Medicine. - 1365-2060. ; 33:9, s. 563-570
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Tidskriftsartikel (refereegranskat)abstract
- Symptoms of infection and tissue pathology are caused by the host response; not by the microbe per se. The same response is also critical for the defence and is needed to clear infection. It is therefore essential to understand how the host response is activated and to identify the critical effector mechanisms of the defence. We have studied these issues in the urinary tract infection (UTI) model. The symptoms of UTI and the host defence both rely on the so-called 'innate' immune system, making this one of the best characterized human disease models of 'innate immunity. We discuss the critical molecular events that determine whether the host response will be activated by P-fimbriated uropathogenic Escherichia coli as well as factors determining whether the patient develops acute pyelonephritis or asymptomatic bacteriuria. We will describe the glycoconjugate receptors used by the P-fimbriated bacteria adhering to host tissues, the recruitment of TLR4 co-receptors and the signalling pathways that allow progression to symptomatic disease, and discuss how these mechanisms are altered in asymptomatic carriers, presenting the possible genetic basis for unresponsiveness. We have shown that neutrophils are the critical effectors of the host defence and that neutrophil dysfunctions lead to acute pyelonephritis and renal scarring. Here we discuss the mechanisms of neutrophil-mediated, chemokine receptor (CXCR1)-dependent clearance, and the defect in interleukin-8 receptor homolog knock-out (IL-8Rh KO) mice and describe the data linking low CXCR1 expression to recurrent pyelonephritis in man, as well as the information on the genetic basis for low CXCR1 expression in affected patients. Finally, the mechanisms of renal scarring in IL8Rh KO mice will be discussed in relation to human disease. Our studies hold the promise to provide a molecular and genetic explanation for disease susceptibility in some patients with UTI and to offer more precise tools for the diagnosis and therapy of these infections.
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| 45. |
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| 46. |
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| 47. |
- Svensson, Majlis, et al.
(författare)
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Acute pyelonephritis and renal scarring are caused by dysfunctional innate immunity in mCxcr2 heterozygous mice.
- 2011
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Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 80:10, s. 1064-1072
-
Tidskriftsartikel (refereegranskat)abstract
- The CXCR1 receptor and chemokine CXCL8 (IL-8) support neutrophil-dependent clearance of uropathogenic Escherichia coli from the urinary tract. CXCR1 is reduced in children prone to pyelonephritis, and heterozygous hCXCR1 polymorphisms are more common in this patient group than in healthy individuals, strongly suggesting a disease association. Since murine CXCR2 (mCXCR2) is functionally similar to human CXCR1, we determined effects of gene heterozygosity on the susceptibility to urinary tract infection by infecting heterozygous (mCxcr2(+/-)) mice with uropathogenic Escherichia coli. Clearance of infection and tissue damage were assessed as a function of innate immunity in comparison to that in knockout (mCxcr2(-/-)) and wild-type (mCxcr2(+/+)) mice. Acute sepsis-associated mortality was increased and bacterial clearance drastically impaired in heterozygous compared to wild-type mice. Chemokine and neutrophil responses were delayed along with evidence of neutrophil retention and unresolved kidney inflammation 1 month after infection. This was accompanied by epithelial proliferation and subepithelial fibrosis. The heterozygous phenotype was intermediate, between knockout and wild-type mice, but specific immune cell infiltrates that accompany chronic infection in knockout mice were not found. Hence, the known heterozygous CXCR1 polymorphisms may predispose patients to acute pyelonephritis and urosepsis.
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| 48. |
- Svensson, Majlis, et al.
(författare)
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Effects of epithelial and neutrophil CXCR2 on innate immunity and resistance to kidney infection.
- 2008
-
Ingår i: Kidney International. - : Elsevier BV. - 1523-1755 .- 0085-2538. ; 74, s. 81-90
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Tidskriftsartikel (refereegranskat)abstract
- The murine chemokine receptor 2 (mCXCR2) controls resistance to urinary tract infection. We have previously shown that mCXCR2 knockout mice develop severe acute pyelonephritis and renal tissue damage with sub-epithelial neutrophil entrapment. In this study we examined the relative importance of neutrophil- and epithelial-specific mCXCR2 expression for bacterial clearance in bone marrow chimeric mice infected with uropathogenic Escherichia coli. Mice expressing mCXCR2 on their neutrophils responded rapidly to experimental urinary tract infection, clearing the infection from the kidneys. Mice lacking epithelial mCXCR2, however, showed delayed exit of neutrophils from the tissues. Mice lacking neutrophil mCXCR2 and mice with no mCXCR2 had no neutrophil recruitment and bacterial clearance. Mice expressing mCXCR2 only in their epithelial cells had a transient epithelial chemokine response; however, neutrophil recruitment was inhibited and bacteria grew without constraint. Our study shows that the expression of mCXCR2 on hematopoietic cells was crucial for bacterial clearance, while its expression on non-bone marrow-derived cells influenced the neutrophil response. These results emphasize the importance of mCXCR2 for the innate defense against urinary tract infection.Kidney International advance online publication, 9 April 2008; doi:10.1038/ki.2008.105.
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| 49. |
- Tenland, Erik, et al.
(författare)
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A novel derivative of the fungal antimicrobial peptide plectasin is active against Mycobacterium tuberculosis
- 2018
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Ingår i: Tuberculosis. - : Elsevier BV. - 1472-9792 .- 1873-281X. ; 113, s. 231-238
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Tidskriftsartikel (refereegranskat)abstract
- Tuberculosis has been reaffirmed as the infectious disease causing most deaths in the world. Co-infection with HIV and the increase in multi-drug resistant Mycobacterium tuberculosis strains complicate treatment and increases mortality rates, making the development of new drugs an urgent priority. In this study we have identified a promising candidate by screening antimicrobial peptides for their capacity to inhibit mycobacterial growth. This non-toxic peptide, NZX, is capable of inhibiting both clinical strains of M. tuberculosis and an MDR strain at therapeutic concentrations. The therapeutic potential of NZX is further supported in vivo where NZX significantly lowered the bacterial load with only five days of treatment, comparable to rifampicin treatment over the same period. NZX possesses intracellular inhibitory capacity and co-localizes with intracellular bacteria in infected murine lungs. In conclusion, the data presented strongly supports the therapeutic potential of NZX in future anti-TB treatment.
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- Tenland, Erik, et al.
(författare)
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Effective delivery of the anti-mycobacterial peptide NZX in mesoporous silica nanoparticles
- 2019
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Ingår i: PLOS ONE. - : PUBLIC LIBRARY SCIENCE. - 1932-6203. ; 14:2
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Tidskriftsartikel (refereegranskat)abstract
- Background Intracellular delivery of antimicrobial agents by nanoparticles, such as mesoporous silica particles (MSPs), offers an interesting strategy to treat intracellular infections. In tuberculosis (TB), Mycobacterium tuberculosis avoids components of the immune system by residing primarily inside alveolar macrophages, which are the desired target for TB therapy. Methods and findings We have previously identified a peptide, called NZX, capable of inhibiting both clinical and multi-drug resistant strains of M. tuberculosis at therapeutic concentrations. In this study we analysed the potential of MSPs containing NZX for the treatment of tuberculosis. The MSPs released functional NZX gradually into simulated lung fluid and the peptide filled MSPs were easily taken up by primary macrophages. In an intracellular infection model, the peptide containing particles showed increased mycobacterial killing compared to free peptide. The therapeutic potential of peptide containing MSPs was investigated in a murine infection model, showing that MSPs preserved the effect to eliminate M. tuberculosis in vivo. Conclusions In this study we found that loading the antimicrobial peptide NZX into MSPs increased the inhibition of intracellular mycobacteria in primary macrophages and preserved the ability to eliminate M. tuberculosis in vivo in a murine model. Our studies provide evidence for the feasibility of using MSPs for treatment of tuberculosis.
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