| 1. |
- Ali, Abukar, 1988, et al.
(författare)
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CTLA4-Ig but not anti-TNF therapy promotes staphylococcal septic arthritis in mice.
- 2015
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Ingår i: The Journal of infectious diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 212:8, s. 1308-1316
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Tidskriftsartikel (refereegranskat)abstract
- The development of biologics has greatly increased the quality of life as well as the life expectancy of many RA patients. However, a large number of these patients are at an increased risk of developing serious infections. The aim of this study was to examine differential effects of anti-TNF versus CTLA4-Ig treatment on both immunological response and host defense in a murine model of septic arthritis.
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| 2. |
- Ali, Abukar, 1988, et al.
(författare)
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IL-1 Receptor Antagonist Treatment Aggravates Staphylococcal Septic Arthritis and Sepsis in Mice.
- 2015
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 10:7
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Tidskriftsartikel (refereegranskat)abstract
- Interleukin-1 receptor antagonist (IL-1Ra) is the primary therapy against autoinflammatory syndromes with robust efficacy in reducing systemic inflammation and associated organ injury. However, patients receiving IL-1Ra might be at increased risk of acquiring serious infections.
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| 3. |
- Boldock, Emma, et al.
(författare)
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Human skin commensals augment Staphylococcus aureus pathogenesis.
- 2018
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Ingår i: Nature microbiology. - : Springer Science and Business Media LLC. - 2058-5276. ; 3:8, s. 881-90
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Tidskriftsartikel (refereegranskat)abstract
- All bacterial infections occur within a polymicrobial environment, from which a pathogen population emerges to establish disease within a host. Emphasis has been placed on prevention of pathogen dominance by competing microflora acting as probiotics1. Here we show that the virulence of the human pathogen Staphylococcus aureus is augmented by native, polymicrobial, commensal skin flora and individual species acting as 'proinfectious agents'. The outcome is pathogen proliferation, but not commensal. Pathogenesis augmentation can be mediated by particulate cell wall peptidoglycan, reducing the S. aureus infectious dose by over 1,000-fold. This phenomenon occurs using a range of S. aureus strains and infection models and is not mediated by established receptor-mediated pathways including Nod1, Nod2, Myd88 and the NLPR3 inflammasome. During mouse sepsis, augmentation depends on liver-resident macrophages (Kupffer cells) that capture and internalize both the pathogen and the proinfectious agent, leading to reduced production of reactive oxygen species, pathogen survival and subsequent multiple liver abscess formation. The augmented infection model more closely resembles the natural situation and establishes the role of resident environmental microflora in the initiation of disease by an invading pathogen. As the human microflora is ubiquitous2, its role in increasing susceptibility to infection by S. aureus highlights potential strategies for disease prevention.
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| 4. |
- Chen, Dongfeng, et al.
(författare)
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Glioma Cell Proliferation Controlled by ERK Activity-Dependent Surface Expression of PDGFRA.
- 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
- Increased PDGFRA signaling is an essential pathogenic factor in many subtypes of gliomas. In this context the cell surface expression of PDGFRA is an important determinant of ligand sensing in the glioma microenvironment. However, the regulation of spatial distribution of PDGFRA in glioma cells remains poorly characterized. Here, we report that cell surface PDGFRA expression in gliomas is negatively regulated by an ERK-dependent mechanism, resulting in reduced proliferation of glioma cells. Glioma tumor tissues and their corresponding cell lines were isolated from 14 patients and analyzed by single-cell imaging and flow cytometry. In both cell lines and their corresponding tumor samples, glioma cell proliferation correlated with the extent of surface expression of PDGFRA. High levels of surface PDGFRA also correlated to high tubulin expression in glioma tumor tissue in vivo. In glioma cell lines, surface PDGFRA declined following treatment with inhibitors of tubulin, actin and dynamin. Screening of a panel of small molecule compounds identified the MEK inhibitor U0126 as a potent inhibitor of surface PDGFRA expression. Importantly, U0126 inhibited surface expression in a reversible, dose- and time-dependent manner, without affecting general PDGFRA expression. Treatment with U0126 resulted in reduced co-localization between PDGFRA and intracellular trafficking molecules e.g. clathrin, RAB11 and early endosomal antigen-1, in parallel with enhanced co-localization between PDGFRA and the Golgi cisternae maker, Giantin, suggesting a deviation of PDGFRA from the endosomal trafficking and recycling compartment, to the Golgi network. Furthermore, U0126 treatment in glioma cells induced an initial inhibition of ERK1/2 phosphorylation, followed by up-regulated ERK1/2 phosphorylation concomitant with diminished surface expression of PDGFRA. Finally, down-regulation of surface PDGFRA expression by U0126 is concordant with reduced glioma cell proliferation. These findings suggest that manipulation of spatial expression of PDGFRA can potentially be used to combat gliomas.
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| 5. |
- Elmwall, Jonas, et al.
(författare)
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Galectin-3 Is a Target for Proteases Involved in the Virulence of Staphylococcus aureus
- 2017
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 85:7
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus is a major cause of skin and soft tissue infection. The bacterium expresses four major proteases that are emerging as virulence factors: aureolysin (Aur), V8 protease (SspA), staphopain A (ScpA), and staphopain B (SspB). We hypothesized that human galectin-3, a beta-galactoside-binding lectin involved in immune regulation and antimicrobial defense, is a target for these proteases and that proteolysis of galectin-3 is a novel immune evasion mechanism. Indeed, supernatants from laboratory strains and clinical isolates of S. aureus caused galectin-3 degradation. Similar proteolytic capacities were found in Staphylococcus epidermidis isolates but not in Staphylococcus saprophyticus. Galectin-3-induced activation of the neutrophil NADPH oxidase was abrogated by bacterium-derived proteolysis of galectin-3, and SspB was identified as the major protease responsible. The impact of galectin-3 and protease expression on S. aureus virulence was studied in a murine skin infection model. In galectin-3 (+)/(+) mice, SspB-expressing S. aureus caused larger lesions and resulted in higher bacterial loads than protease-lacking bacteria. No such difference in bacterial load or lesion size was detected in galectin-3 (+)/(+) mice, which overall showed smaller lesion sizes than the galectin-3 (+)/(+) animals. In conclusion, the staphylococcal protease SspB inactivates galectin-3, abrogating its stimulation of oxygen radical production in human neutrophils and increasing tissue damage during skin infection.
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| 6. |
- Fatima, Farah, et al.
(författare)
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Radiological features of experimental staphylococcal septic arthritis by micro computed tomography scan.
- 2017
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:2
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Tidskriftsartikel (refereegranskat)abstract
- Permanent joint dysfunction due to bone destruction occurs in up to 50% of patients with septic arthritis. Recently, imaging technologies such as micro computed tomography (μCT) scan have been widely used for preclinical models of autoimmune joint disorders. However, the radiological features of septic arthritis in mice are still largely unknown.NMRI mice were intravenously or intra-articularly inoculated with S. aureus Newman or LS-1 strain. The radiological and clinical signs of septic arthritis were followed for 10 days using μCT. We assessed the correlations between joint radiological changes and clinical signs, histological changes, and serum levels of cytokines.On days 5-7 after intravenous infection, bone destruction verified by μCT became evident in most of the infected joints. Radiological signs of bone destruction were dependent on the bacterial dose. The site most commonly affected by septic arthritis was the distal femur in knees. The bone destruction detected by μCT was positively correlated with histological changes in both local and hematogenous septic arthritis. The serum levels of IL-6 were significantly correlated with the severity of joint destruction.μCT is a sensitive method for monitoring disease progression and determining the severity of bone destruction in a mouse model of septic arthritis. IL-6 may be used as a biomarker for bone destruction in septic arthritis.
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| 7. |
- Jarneborn, Anders, et al.
(författare)
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Tofacitinib treatment aggravates Staphylococcus aureus septic arthritis, but attenuates sepsis and enterotoxin induced shock in mice
- 2020
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- Tofacitinib, a janus kinase inhibitor, is a novel immunosuppressive drug for treatment of rheumatoid arthritis (RA). Septic arthritis (SA) and sepsis caused by Staphylococcus aureus (S. aureus), for which RA patients are at risk, are infections with high mortality. The aim of this study was to investigate the effect of tofacitinib on S. aureus infections using mouse models. In vitro tofacitinib treated mouse splenocytes were stimulated with S. aureus derived stimuli. Mice pre-treated with tofacitinib were inoculated intravenously with either arthritogenic- or septic doses of S. aureus. Arthritis severity and mortality were compared between groups. Additionally, pre-treated mice were challenged with staphylococcal toxin TSST-1 to induce shock. Tofacitinib inhibited splenocyte proliferation and IFN-gamma production in response to TSST-1 and dead S. aureus. In SA, tofacitinib treatment aggravated arthritis with more severe bone erosions. However, in sepsis, treated mice displayed significantly prolonged survival compared to controls. Similarly, in staphylococcal enterotoxin-induced shock tofacitinib pre-treatment, but not late treatment dramatically reduced mortality, which was accompanied by decreased levels of TNF-alpha and IFN-gamma. Our findings show that tofacitinib treatment increase susceptibility of SA in mice, but has a positive effect on survival in S. aureus-induced sepsis and a strong protective effect in toxin-induced shock.
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| 8. |
- Kwiecinski, Jakub, 1985, et al.
(författare)
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Staphylokinase controls Staphylococcus aureus biofilm formation and detachment through host plasminogen activation.
- 2016
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Ingår i: The Journal of infectious diseases. - : Oxford University Press (OUP). - 0022-1899 .- 1537-6613. ; 213:1, s. 139-148
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus biofilms, a leading cause of persistent infections, are highly resistant to immune defenses and antimicrobial therapies. In this study, we investigated the contribution of fibrin and staphylokinase to biofilm formation. Both in clinical S. aureus isolates and in laboratory strains, high staphylokinase-producing strains formed less biofilm than strains that lacked staphylokinase, suggesting that staphylokinase prevents biofilm formation. Additionally, staphylokinase induced detachment of mature biofilms. This effect depended on plasminogen activation by staphylokinase. Host-derived fibrin, the main substrate cleaved by staphylokinase-activated plasminogen, was a major component of biofilm matrix and dissolution of this fibrin scaffold greatly increased susceptibility of biofilms to antibiotics and neutrophil phagocytosis. Staphylokinase also attenuated biofilm-associated catheter infections in mouse models. In conclusion, our results reveal a novel role for staphylokinase-induced plasminogen activation that prevents S. aureus biofilm formation and induces detachment of existing biofilms through proteolytic cleavage of biofilm matrix components.
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| 9. |
- Kwiecinski, Jakub, 1985, et al.
(författare)
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Tissue Plasminogen Activator Coating on Implant Surfaces Reduces Staphylococcus aureus Biofilm Formation
- 2016
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Ingår i: Applied and Environmental Microbiology. - : American Society for Microbiology. - 0099-2240 .- 1098-5336. ; 82:1, s. 394-401
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus aureus biofilm infections of indwelling medical devices are a major medical challenge because of their high prevalence and antibiotic resistance. As fibrin plays an important role in S. aureus biofilm formation, we hypothesize that coating of the implant surface with fibrinolytic agents can be used as a new method of antibiofilm prophylaxis. The effect of tissue plasminogen activator (tPA) coating on S. aureus biofilm formation was tested with in vitro microplate biofilm assays and an in vivo mouse model of biofilm infection. tPA coating efficiently inhibited biofilm formation by various S. aureus strains. The effect was dependent on plasminogen activation by tPA, leading to subsequent local fibrin cleavage. A tPA coating on implant surfaces prevented both early adhesion and later biomass accumulation. Furthermore, tPA coating increased the susceptibility of biofilm infections to antibiotics. In vivo, significantly fewer bacteria were detected on the surfaces of implants coated with tPA than on control implants from mice treated with cloxacillin. Fibrinolytic coatings (e.g., with tPA) reduce S. aureus biofilm formation both in vitro and in vivo, suggesting a novel way to prevent bacterial biofilm infections of indwelling medical devices.
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| 10. |
- Lin, Chen, et al.
(författare)
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Concomitant use of Ad5/35 chimeric oncolytic adenovirus with TRAIL gene and taxol produces synergistic cytotoxicity in gastric cancer cells
- 2009
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Ingår i: Cancer Letters. - : Elsevier BV. - 1872-7980 .- 0304-3835. ; 284:2, s. 141-148
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Tidskriftsartikel (refereegranskat)abstract
- Chimeric adenoviral vectors possessing fiber derived from human adenovirus subgroup B (Ad35) have been developed for their high infection efficiency in cell types which are refractory to adenovirus serotype 5 (Subgroup C) The present study constructed an E1B-deleted chimeric oncolytic adenovirus, SG235-TRAIL, which carries a human TRAIL gene expression cassette and whose fiber shaft and knob domains are from serotype AM. It was found that SG235-TRAIL preferentially replicated in gastric cancer cell lines, SGC-7901 and BGC-823 compared to in normal human fibroblast BJ cells. Also, when compared with a replication-deficient chimeric vector Ad5/35-TRAIL, SG235-TRAIL mediated a higher level of the transgene expression via viral replication in the cancer cells. Further, because of the more efficient cell-entry and infection, SG235-TRAIL induced stronger cell apoptosis than the Ad5 CRAD vector, ZD55-TRAIL In addition, SG235-TRAIL in combination with the chemotherapeutic drug, taxol, produced a synergistic cytotoxic effect in cancer cells in vitro without causing significant toxicity to normal cells. In the gastric tumor xenograft mouse model, intratumoral SG235-TRAIL injection produced a significant antitumor effect 14 days after treatment. Pathological examination demonstrated TRAIL expression and associated apoptosis in majority of SG235-TRAIL-treated tumor cells. These results suggest that SG235-TRAIL is a potential novel, efficient anti-cancer agent, and in combination with taxol, it would be even more useful with considerably low toxic side effects. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
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| 11. |
- Marco, Maugeri, 1983, et al.
(författare)
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Linkage between endosomal escape of LNP-mRNA and loading into EVs for transport to other cells
- 2019
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- RNA-based therapeutics hold great promise for treating diseases and lipid nanoparticles (LNPs) represent the most advanced platform for RNA delivery. However, the fate of the LNP-mRNA after endosome-engulfing and escape from the autophagy-lysosomal pathway remains unclear. To investigate this, mRNA (encoding human erythropoietin) was delivered to cells using LNPs, which shows, for the first time, a link between LNP-mRNA endocytosis and its packaging into extracellular vesicles (endo-EVs: secreted after the endocytosis of LNP-mRNA). Endosomal escape of LNP-mRNA is dependent on the molar ratios between ionizable lipids and mRNA nucleotides. Our results show that fractions of ionizable lipids and mRNA (1:1 molar ratio of hEPO mRNA nucleotides:ionizable lipids) of endocytosed LNPs were detected in endo-EVs. Importantly, these EVs can protect the exogenous mRNA during in vivo delivery to produce human protein in mice, detected in plasma and organs. Compared to LNPs, endo-EVs cause lower expression of inflammatory cytokines.
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| 12. |
- Mohammad, Majd, et al.
(författare)
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RAGE Deficiency Impairs Bacterial Clearance in Murine Staphylococcal Sepsis, but Has No Significant Impact on Staphylococcal Septic Arthritis.
- 2016
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 11:12
-
Tidskriftsartikel (refereegranskat)abstract
- Septic arthritis is a serious joint disease often caused by Staphylococcus aureus (S. aureus). Receptor for Advanced Glycation End products (RAGE) has an important role in several infections. We sought to investigate the role of RAGE in staphylococcal septic arthritis and sepsis in mice.Wild-type (WT) and RAGE deficient (RAGE-/-) mice were intra-articularly or intravenously inoculated with an arthritic or septic dose of S. aureus LS-1 strain. Clinical arthritis, weight development and mortality were monitored for 14 days. Serum levels of cytokines, kidney bacterial loads as well as micro-CT and histopathology of the joints were assessed.RAGE-/- mice with septic arthritis had significantly lower IL-17A and higher bone mineral density (BMD) compared to the control group. However, no significant differences between the groups were observed regarding the weight loss, the severity and frequency of arthritis, and bacterial loads in the kidneys. In mice with sepsis, the overall mortality rate was similar in RAGE-/- (39%) and in WT mice (45%). However, RAGE-/- mice with sepsis had significantly higher bacterial load in their kidneys compared to the WT controls. In line with data from hematogenous S. aureus arthritis, RAGE deficiency had no impact on arthritis severity in local joint infection.Our results indicate that lack of RAGE has no significant impact on septic arthritis. However, RAGE-/- mice had significantly higher BMD compared to WT mice, which coincided with lower IL-17A in RAGE-/- mice. In sepsis, RAGE deficiency impairs bacterial kidney clearance.
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| 13. |
- Mohammad, Majd, et al.
(författare)
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Staphylococcus aureus lipoproteins promote abscess formation in mice, shielding bacteria from immune killing.
- 2021
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Ingår i: Communications biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 4:1
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Tidskriftsartikel (refereegranskat)abstract
- Despite being a major bacterial factor in alerting the human immune system, the role of Staphylococcus aureus (S. aureus) lipoproteins (Lpp) in skin infections remains largely unknown. Here, we demonstrated that subcutaneous injection of S. aureus Lpp led to infiltration of neutrophils and monocytes/macrophages and induced skin lesions in mice. Lipid-moiety of S. aureus Lpp and host TLR2 was responsible for such effect. Lpp-deficient S. aureus strains exhibited smaller lesion size and reduced bacterial loads than their parental strains; the altered phenotype in bacterial loads was TLR2-independent. Lpp expression in skin infections contributed to imbalanced local hemostasis toward hypercoagulable state. Depletion of leukocytes or fibrinogen abrogated the effects induced by Lpp in terms of skin lesions and bacterial burden. Our data suggest that S. aureus Lpp induce skin inflammation and promote abscess formation that protects bacteria from innate immune killing. This suggests an intriguing bacterial immune evasion mechanism.
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| 14. |
- Mohammad, Majd, et al.
(författare)
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The role of Staphylococcus aureus lipoproteins in hematogenous septic arthritis.
- 2020
-
Ingår i: Scientific reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Permanent joint dysfunction is a devastating complication in patients with septic arthritis. Staphylococcus aureus (S. aureus) lipoproteins (Lpp), the predominant ligands for TLR2, are known to be arthritogenic and induce bone destruction when introduced directly into the joint. Here, we aim to investigate the importance of S. aureus Lpp and TLR2 in a hematogenous septic arthritis model, which is the most common route of infection in humans. C57BL/6 wild-type and TLR2 deficient mice were intravenously inoculated with S. aureus Newman parental strain or its lipoprotein-deficient Δlgt mutant strain. The clinical course of septic arthritis, radiological changes, and serum levels of cytokines and chemokines, were assessed. Newman strain induced more severe and frequent clinical septic polyarthritis compared to its Δlgt mutant in TLR2 deficient mice, but not in wild-type controls. Bone destruction, however, did not differ between groups. Lpp expression was associated with higher mortality, weight loss as well as impaired bacterial clearance in mouse kidneys independent of TLR2. Furthermore, Lpp expression induced increased systemic pro-inflammatory cytokine and neutrophil chemokine release. Staphylococcal Lpp are potent virulence factors in S. aureus systemic infection independent of host TLR2 signalling. However, they have a limited impact on bone erosion in hematogenous staphylococcal septic arthritis.
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| 15. |
- Mohammad, Majd, et al.
(författare)
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The YIN and YANG of lipoproteins in developing and preventing infectious arthritis by Staphylococcus aureus.
- 2019
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Ingår i: PLoS pathogens. - : Public Library of Science (PLoS). - 1553-7374. ; 15:6
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Tidskriftsartikel (refereegranskat)abstract
- Rapid bone destruction often leads to permanent joint dysfunction in patients with septic arthritis, which is mainly caused by Staphylococcus aureus (S. aureus). Staphylococcal cell wall components are known to induce joint inflammation and bone destruction. Here, we show that a single intra-articular injection of S. aureus lipoproteins (Lpps) into mouse knee joints induced chronic destructive macroscopic arthritis through TLR2. Arthritis was characterized by rapid infiltration of neutrophils and monocytes. The arthritogenic effect was mediated mainly by macrophages/monocytes and partially via TNF-α but not by neutrophils. Surprisingly, a S. aureus mutant lacking Lpp diacylglyceryl transferase (lgt) caused more severe joint inflammation, which coincided with higher bacterial loads of the lgt mutant in local joints than those of its parental strain. Coinjection of pathogenic S. aureus LS-1 with staphylococcal Lpps into mouse knee joints caused improved bacterial elimination and diminished bone erosion. The protective effect of the Lpps was mediated by their lipid moiety and was fully dependent on TLR2 and neutrophils. The blocking of CXCR2 on neutrophils resulted in total abrogation of the protective effect of the Lpps. Our data demonstrate that S. aureus Lpps elicit innate immune responses, resulting in a double-edged effect. On the one hand, staphylococcal Lpps boost septic arthritis. On the other hand, Lpps act as adjuvants and activate innate immunity, which could be useful for combating infections with multiple drug-resistant strains.
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| 16. |
- Na, Manli, et al.
(författare)
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Adenovirus assembly is impaired by BMI1-related histone deacetylase activity.
- 2014
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Ingår i: Virology. - : Elsevier BV. - 1096-0341 .- 0042-6822. ; 456:Apr 17, s. 227-237
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Tidskriftsartikel (refereegranskat)abstract
- Polycomb ring finger oncogene BMI1 (B cell-specific Moloney murine leukemia virus integration site 1) plays a critical role in development of several types of cancers. Here, we report an inverse relationship between levels of BMI1 expression and adenovirus (Ad) progeny production. Enforced BMI1 expression in A549 cells impaired Ad progeny production. In contrast, knocking-down of endogenous BMI1 expression enhanced progeny production of a conditionally replicating Ad and wild-type Ad5 and Ad11p. Ad vectors overexpressing BMI1 were not impaired in the replication of progeny genomes and in the expression of E1A and Ad structural proteins. However, 293 cells infected by Ad vector overexpressing BMI1 contained a large proportion of morphologically irregular Ad particles. This effect was reversed in 293 cells pre-treated with the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) in parallel with the production of infectious Ad particles. Our findings suggest an inhibitory role of BMI1 in Ad morphogenesis that can be implied in Ad tropism and Ad-mediated cancer therapy.
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| 17. |
- Na, Manli, et al.
(författare)
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Both anti-TNF and CTLA4 Ig treatments attenuate the disease severity of staphylococcal dermatitis in mice.
- 2017
-
Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- RA patients being treated with biologics are known to have an increased risk of infections. We recently demonstrated that both CTLA4 Ig and anti-TNF treatment aggravate systemic Staphylococcus aureus (S. aureus) infection in mice, but with distinct clinical manifestations. However, the effects of CTLA4 Ig and anti-TNF treatments on a local S. aureus infection (e.g., skin infection) might differ from their effects on a systemic infection.The aim of this study was to examine the differential effects of anti-TNF versus CTLA4 Ig treatment on S. aureus skin infections in mice.Abatacept (CTLA4 Ig), etanercept (anti-TNF treatment) or PBS was given to NMRI mice subcutaneously inoculated with S. aureus strain SH1000. The clinical signs of dermatitis, along with histopathological changes due to skin infection, were compared between the groups.Both CTLA4 Ig and anti-TNF treatment resulted in less severe skin infections and smaller post-infectious hyperpigmentation compared with controls. Consistent with the clinical signs of dermatitis, smaller lesion size, more epithelial hyperplasia and more granulation were found in skin biopsies from mice receiving anti-TNF compared with PBS controls. However, both CTLA4 Ig and anti-TNF therapy tended to prolong the healing time, although this finding was not statistically significant. Serum MCP-1 levels were elevated in the anti-TNF group relative to the CTLA4 Ig and PBS groups, whereas IL-6 levels were higher in PBS controls than in the other two groups. Both anti-TNF and CTLA4 Ig treatments tended to down-regulate the necrosis/apoptosis ratio in the locally infected skin tissue. Importantly, no tangible difference was found in the bacterial burden among groups.Both CTLA4 Ig and anti-TNF therapies attenuate disease severity but may prolong the healing time required for S. aureus skin infections. Neither treatment has an impact on bacterial clearance in skin tissues.
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| 18. |
- Na, Manli, et al.
(författare)
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Deficiency of the complement component 3 but not factor B aggravates Staphylococcus aureus septic arthritis in mice.
- 2016
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Ingår i: Infection and immunity. - 1098-5522. ; 84:4, s. 930-939
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Tidskriftsartikel (refereegranskat)abstract
- The complement system plays an essential role in the innate immune response and protection against bacterial infections. However, detailed knowledge regarding the role of complement in Staphylococcus aureus (S. aureus) septic arthritis is still largely missing. In this study, we elucidated the role of selected complement proteins in S. aureus septic arthritis. Mice lacking the complement component 3 (C3(-/-)), complement factor B (fB(-/-)), receptor for C3 derived anaphylatoxin C3a (C3aR(-/-)) and wild-type (WT) control mice were intravenously or intraarticularly inoculated with Staphylococcus aureus Newman strain. The clinical course of septic arthritis as well as histopathological and radiological changes in joints were assessed. After intravenous inoculation, arthritis severity and frequency was significantly higher in C3(-/-) mice compared to WT controls, whereas fB(-/-) mice displayed intermediate arthritis severity and frequency. This was in accordance with both histopathological and radiological findings. C3 but not fB deficiency was associated with larger weight loss, more frequent kidney abscesses, as well as higher bacterial burden in kidneys. S. aureus opsonised with C3(-/-) sera displayed decreased uptake by mouse peritoneal macrophages compared with bacteria opsonised with WT or fB(-/-) sera. C3aR deficiency had no effect on the course of hematogenous S. aureus septic arthritis. We conclude that C3 deficiency increases the susceptibility to hematogenous S. aureus septic arthritis and impairs host bacterial clearance, conceivably due to diminished opsonisation and phagocytosis of S. aureus.
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| 19. |
- Na, Manli, et al.
(författare)
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Design of Ad5F35 vectors for coordinated dual gene expression in candidate human hematopoietic stem cells.
- 2010
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Ingår i: Experimental Hematology. - : Elsevier BV. - 1873-2399 .- 0301-472X. ; Apr 8, s. 446-452
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Adenoviral vector mediated gene expression is an attractive approach to manipulate or report gene expression in human hematopoietic stem cells (HSC), when transient gene expression is preferred. Previous studies have demonstrated that fiber retargeted Ad5F35 vectors can mediate efficient gene transfer into human HSCs. In this study, we have investigated the potential of bi-directional promoter controlled Ad5F35 vector for coordinated dual gene expression in candidate HSCs. MATERIAL AND METHODS: We have engineered Ad5F35-DeltaLNGFR-BiDp encoding kinase domain deleted low-affinity NGF receptor (DeltaLNGFR) and green fluorescent protein (GFP) expression cassette controlled by a synthetic bi-directional promoter, which is composed of human phosphoglycerate kinase (PGK) promoter and minimal core promoter from human cytomegalovirus (mCMV). The expression pattern of DeltaLNGFR and GFP following Ad5F35-DeltaLNGFR-BiDp gene transfer in various cell types including candidate HSCs was compared to Ad5F35-DeltaLNGFR-IRES vector encoding PGK promoter controlled bicistronic expression cassette for DeltaLNGFR and GFP. RESULTS AND CONCLUSIONS: Using Ad5F35-DeltaLNGFR-BiDp, we demonstrated a coordinated, high-level dual gene expression in leukemic cells and cord blood CD34(+) cells. However, the ability of Ad5F35-DeltaLNGFR-BiDp-GFP for coordinated dual gene expression varied significantly between re-populating progenitor cells. In NOD/SCID mice bone marrow transplantation assay, sorted CD34(+)/DeltaLNGFR(+)/GFP(+) cells following infection with Ad5F35-DeltaLNGFR-BiDp showed predominantly myeloid lineage reconstitution with limited lymphoid lineage differentiation capacity, whereas the CD34(+)/DeltaLNGFR(+)/GFP(-) cells exhibited both myeloid and lymphoid reconstitution. This study indicates that bi-directional promoter controlled Ad5F35 vector such as Ad5F35-DeltaLNGFR-BiDp can be particularly useful for manipulation of myeloid progenitor cells and potentially also in myeloid lineage leukemic cells.
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| 20. |
- Na, Manli
(författare)
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HOST EPIGENETIC REGULATOR BMI1 AND VIRAL FIBER PROTEIN FOR EQUILIBRIUM BETWEEN ADENOVIRUS AND HOST
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Human adenoviruses (Ads) are broadly used in cancer gene therapy, vaccine development and gene delivery. The modified Ad5 or Ad2 viruses have been successfully used as oncolytic agents in pre-clinical studies. However they could not be translated into clinic utility due to a number of limitations including inefficient Ad spread among tumor cells. The cancer cell killing capacity of oncolytic Ad is dependent not only on the efficiency of Ad replication, but also on the efficiency of progeny dispersal and propagation of infection within cancer tissue. In this thesis, we believe that both viral and host cell factors regulate Ad propagation and spread process and consequently affect the co-existence interplay between Ad and host cells. Our projects aim to identify such factors from Ad as well as host cell side, and to clarify their role in regulating Ad propagation and spread. To identity viral factors, we investigated the kinetics of cell killing and Ad propagation following Ad infection at low multiplicity. Our results showed that prior to the release of Ad progenies, Ad infected cells secrete free fiber molecules in an excess, which mask Ad receptor molecules on non-infected bystander host cells, thus preventing these cells from efficient Ad infection and thereby promoting Ad and host cell co-existence. This is advantageous to Ad propagation and persistency of infection compared to the killing of all host cells with rapid kinetics. However, this is disadvantageous if Ad is used as oncolytic agents for therapeutic purposes. To identity host factors, we investigated the effect of polycomb gene BMI1 on Ad propagation. BMI1 is broadly overexpressed in various cancers. By retroviral vector mediated enforced BMI1 overexpression or siRNA mediated down-regulation of endogenous BMI1 expression, we demonstrated an inverse correlation between the Ad progeny production and the levels of BMI1 expression. This effect was not related to the cell cycle status and the receptor dependent Ad infectivity in host cells; nor to the replication of Ad genome and the production of Ad structural proteins. Instead, BMI1 overexpression impaired the morphogenesis of Ad particles, which could be reversed by TSA mediated inhibition of HDAC activity. Our findings indicate overexpression of BMI1 as a limiting factor in cancer therapy based on oncolytic Ad. So inhibition of BMI1 expression or BMI1-related HDAC activity may improve the functionality of oncolytic Ads in cancer therapy. To explore new approaches in Ad vector mediated dual gene expression in human hematopoietic stem cells (HSC), we generated an Ad vector, Ad5F35- ΔLNGFR-BiDp-GFP, encoding kinase domain deleted low-affinity NGF receptor (ΔLNGFR) and green fluorescent protein (GFP) expression cassette controlled by a synthetic bi-directional promoter. Our data showed that Ad5F35-ΔLNGFR-BiDp vector is highly active in directing dual gene expression in HSCs and most leukemic cell types tested, but the relative levels of dual gene expression by this vector is strongly cell-type dependent.
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| 21. |
- Na, Manli, et al.
(författare)
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Lack of Receptor for Advanced Glycation End products leads to less severe staphylococcal skin infection but more skin abscesses and prolonged wound healing.
- 2018
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Ingår i: The Journal of infectious diseases. - : Oxford University Press (OUP). - 1537-6613 .- 0022-1899. ; 218:5, s. 791-800
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Tidskriftsartikel (refereegranskat)abstract
- Lack of Receptor for Advanced Glycation End products (RAGE) ameliorates several infections including Staphylococcus aureus (S. aureus) pneumonia. We sought to investigate the role of RAGE in staphylococcal skin infection in mice.Wild-type (WT) and RAGE deficient (RAGE-/-) mice were subcutaneously inoculated with S. aureus SH1000 strain in abscess forming dose or necrotic dose. Clinical signs of dermatitis, along with histopathological changes, were compared between the groups.The skin lesion size was smaller in RAGE-/- mice. Infected RAGE-/- mice expressed lower pro-inflammatory cytokines in local skins compared to control mice. Low dose of bacteria caused more abscess formation in RAGE-/- mice compared to skin necrosis that was more often observed in WT mice. As a result of more abscess formation, the wound healing was prolonged in RAGE-/- mice. Importantly, RAGE-/- mice had lower bacterial loads in the skin than controls, which is correlated with higher local levels of myeloperoxidase before skin infection. In vitro, enhanced phagocytic capacity of neutrophils and macrophages obtained from RAGE-/- mice compared to control mice was observed.RAGE deficiency up-regulates phagocytic capacity of phagocytes, resulting in lower bacterial burden in local skin and milder skin lesions in mice with staphylococcal skin infection.
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| 22. |
- Na, Manli, et al.
(författare)
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The Expression of von Willebrand Factor-Binding Protein Determines Joint-Invading Capacity of Staphylococcus aureus, a Core Mechanism of Septic Arthritis.
- 2020
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Ingår i: mBio. - 2150-7511. ; 11:6
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Tidskriftsartikel (refereegranskat)abstract
- Septic arthritis, one of the most dangerous joint diseases, is predominantly caused by Staphylococcus aureus In contrast, coagulase-negative staphylococci are rarely found in septic arthritis. We hypothesize that coagulases released by S. aureus, including coagulase (Coa) and von Willebrand factor-binding protein (vWbp), play potent roles in the induction of septic arthritis. Four isogenic S. aureus strains differing in expression of coagulases (wild-type [WT] Newman, Δcoa, Δvwb, and Δcoa Δvwb) were used to induce septic arthritis in both wild-type and von Willebrand factor (vWF)-deficient mice. Septic arthritis severity was greatly reduced when wild-type mice were infected with the Δcoa Δvwb and Δvwb variants compared to WT or Δcoa strains, suggesting that vWbp rather than Coa is a major virulence factor in S. aureus septic arthritis. vWF-deficient mice were more susceptible to bone damage in septic arthritis, especially when the Δvwb strain was used. Importantly, no difference in arthritis severity between the Δvwb and WT strains was observed in vWF-deficient mice. Collectively, we conclude that vWbp production by S. aureus enhances staphylococcal septic arthritis.IMPORTANCE Septic arthritis remains one of the most dangerous joint diseases with a rapidly progressive disease character. Despite advances in the use of antibiotics, permanent reductions in joint function due to joint deformation and deleterious contractures occur in up to 50% of patients with septic arthritis. So far, it is still largely unknown how S. aureus initiates and establishes joint infection. Here, we demonstrate that von Willebrand factor-binding protein expressed by S. aureus facilitates the initiation of septic arthritis. Such effect might be mediated through its interaction with a host factor (von Willebrand factor). Our finding contributes significantly to the full understanding of septic arthritis etiology and will pave the way for new therapeutic modalities for this devastating disease.
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| 23. |
- Rebetz, Johan, et al.
(författare)
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Fiber mediated receptor masking in non-infected bystander cells restricts adenovirus cell killing effect but promotes adenovirus host co-existence.
- 2009
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 4:12
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Tidskriftsartikel (refereegranskat)abstract
- The basic concept of conditionally replicating adenoviruses (CRAD) as oncolytic agents is that progenies generated from each round of infection will disperse, infect and kill new cancer cells. However, CRAD has only inhibited, but not eradicated tumor growth in xenograft tumor therapy, and CRAD therapy has had only marginal clinical benefit to cancer patients. Here, we found that CRAD propagation and cancer cell survival co-existed for long periods of time when infection was initiated at low multiplicity of infection (MOI), and cancer cell killing was inefficient and slow compared to the assumed cell killing effect upon infection at high MOI. Excessive production of fiber molecules from initial CRAD infection of only 1 to 2% cancer cells and their release prior to the viral particle itself caused a tropism-specific receptor masking in both infected and non-infected bystander cells. Consequently, the non-infected bystander cells were inefficiently bound and infected by CRAD progenies. Further, fiber overproduction with concomitant restriction of adenovirus spread was observed in xenograft cancer therapy models. Besides the CAR-binding Ad4, Ad5, and Ad37, infection with CD46-binding Ad35 and Ad11 also caused receptor masking. Fiber overproduction and its resulting receptor masking thus play a key role in limiting CRAD functionality, but potentially promote adenovirus and host cell co-existence. These findings also give important clues for understanding mechanisms underlying the natural infection course of various adenoviruses.
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| 24. |
- Su, Changqing, et al.
(författare)
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Gene-Viral Cancer Therapy Using Dual-Regulated Oncolytic Adenovirus with Antiangiogenesis Gene for Increased Efficacy.
- 2008
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Ingår i: Molecular Cancer Research. - 1557-3125. ; 6, s. 568-575
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Tidskriftsartikel (refereegranskat)abstract
- Conditionally replicative adenovirus (CRAD) represents a promising approach for cancer therapy. Several CRADs controlled by the human telomerase reverse transcriptase promoter have been developed. However, because of their replicative capacity, the importance of cancer specificity for CRADs needs to be further emphasized. In this study, we have developed a novel dual-regulated CRAD, CNHK500-mE, which has its E1a and E1b gene controlled by the human telomerase reverse transcriptase promoter and the hypoxia response element, respectively. It also carries a mouse endostatin expression cassette controlled by the cytomegalovirus promoter. These properties allow for increased cancer cell targeting specificity and decreased adverse side effects. We showed that CNHK500-mE preferentially replicated in cancer cells. Compared with a replication-defective vector carrying the same endostatin expression cassette, CNHK500-mE-mediated transgene expression level was markedly increased via viral replication within cancer cells. In the nasopharyngeal tumor xenograft model, CNHK500-mE injection resulted in antitumor efficacy at day 7 after therapy. Three weeks later, it led to significant inhibition of xenograft tumor growth due to the combined effects of viral oncolytic therapy and antiangiogenesis gene therapy. Pathologic examination showed that most cancer cells were positive for adenoviral capsid protein and for apoptotic terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling in the CNHK500-mE-treated tumor tissues, and the microvessels in these tumor tissues were diminished in quantity and abnormal in morphology. These results suggest that, as a potential cancer therapeutic agent, the CNHK500-mE is endowed with higher specificity to cancer cells and low cytotoxicity to normal cells. (Mol Cancer Res 2008;6(4):OF1-8).
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