| 1. |
- Lood, Christian, et al.
(författare)
-
IgG glycan hydrolysis by endoglycosidase S diminishes the proinflammatory properties of immune complexes from patients with systemic lupus erythematosus: A possible new treatment?
- 2012
-
Ingår i: Arthritis and Rheumatism. - : Wiley. - 1529-0131 .- 0004-3591. ; 64:8, s. 2698-2706
-
Tidskriftsartikel (refereegranskat)abstract
- Objective Systemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in several organ systems, related to the presence of circulating and tissue-deposited immune complexes (ICs) that stimulate leukocytes through Fc? receptors (Fc?R) with subsequent inflammation. Treatment with endoglycosidase S (EndoS), an IgG glycanhydrolyzing bacterial enzyme from Streptococcus pyogenes, has shown beneficial effects in several experimental animal models of chronic inflammatory disease. This study was undertaken to investigate whether EndoS affects the proinflammatory properties of ICs and has the potential to be developed as a therapy for SLE. Methods ICs purified from SLE patients or RNA-containing ICs formed in vitro were treated with EndoS and used in several assays reflecting different important features of SLE pathogenesis, such as phagocytosis by polymorphonuclear cells (PMNs) and plasmacytoid dendritic cells (PDCs), complement activation, and interferon-a (IFNa) production by PDCs. Results EndoS treatment abolished all proinflammatory properties of the ICs investigated. This included Fc?R-mediated phagocytosis by PDCs (P = 0.001) and subsequent production of IFNa (P = 0.002), IC-induced classical pathway of complement activation (P = 0.008), chemotaxis, and oxidative burst activity of PMNs (P = 0.002). EndoS treatment also had a direct effect on the molecular structure of ICs, causing decreased IC size and glycosylation. Conclusion Our findings indicate that EndoS treatment has prominent effects on several pathogenetically important IC-mediated events, and suggest that EndoS has the potential to be developed as a novel therapy for SLE.
|
|
| 2. |
- Lood, Christian, et al.
(författare)
-
IgG glycan hydrolysis by EndoS diminishes the pro-inflammatory properties of immune complexes from patients with SLE : a possible new treatment?
- 2012
-
Ingår i: Arthritis and Rheumatism. - : Wiley. - 0004-3591 .- 1529-0131. ; 64:8, s. 2698-2706
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVESystemic lupus erythematosus (SLE) is an autoimmune disease with chronic or episodic inflammation in several organ systems, related to the presence of circulating and tissue-deposited immune complexes (ICs) which stimulate leukocytes through FcγRs with subsequent inflammation. Treatment with EndoS, an IgG glycan hydrolyzing bacterial enzyme from Streptococcus pyogenes, has shown beneficial effects in several experimental animal models of chronic inflammatory disease. In the present study we asked if EndoS could affect pro-inflammatory properties of ICs and have the potential to be developed as a therapy in SLE.METHODSICs, purified from SLE patients or RNA-containing ICs formed in vitro, were treated with EndoS and used in several assays reflecting different important parts of SLE pathogenesis such as phagocytosis by polymorphonuclear neutrophils (PMNs) and plasmacytoid dendritic cells (pDCs), complement activation and IFNα production by pDCs.RESULTSOur results demonstrate that EndoS treatment could abolish all pro-inflammatory properties of ICs investigated. This includes FcγR-mediated phagocytosis by pDCs (p<0.0001) and subsequent production of IFNα (p<0.0001), IC-induced classical complement pathway activation (p<0.0001), chemotaxis and oxidative burst activity of PMNs (p=0.002). We could also demonstrate direct effects on the molecular structure of ICs after EndoS treatment with decreased size and glycosylation patterns.CONCLUSIONSProminent effects of EndoS treatment were seen in several pathogenetically important IC-mediated events and our data suggest that EndoS have the potential to be developed as a novel therapy in SLE.
|
|
| 3. |
|
|
| 4. |
- Allhorn, Maria, et al.
(författare)
-
A novel enzyme with antioxidant capacity produced by the ubiquitous skin colonizer Propionibacterium acnes
- 2016
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
-
Tidskriftsartikel (refereegranskat)abstract
- The role of the skin microbiota in human health is poorly understood. Here, we identified and characterized a novel antioxidant enzyme produced by the skin microbiota, designated RoxP for radical oxygenase of Propionibacterium acnes. RoxP is uniquely produced by the predominant skin bacterium P. acnes, with no homologs in other bacteria; it is highly expressed and strongly secreted into culture supernatants. We show that RoxP binds heme, reduces free radicals, and can protect molecules from oxidation. Strikingly, RoxP is crucial for the survival of P. acnes in oxic conditions and for skin colonization of P. acnes ex vivo. Taken together, our study strongly suggests that RoxP facilitates P. acnes' survival on human skin, and is an important beneficial factor for the host-commensal interaction. Thus, RoxP is the first described skin microbiota-derived mutualistic factor that potentially can be exploited for human skin protection.
|
|
| 5. |
- Andersson, Tilde, et al.
(författare)
-
Biogeographical variation in antimicrobial resistance in rivers is influenced by agriculture and is spread through bacteriophages
- 2022
-
Ingår i: Environmental Microbiology. - : Wiley. - 1462-2912 .- 1462-2920. ; 24:10, s. 4869-4884
-
Tidskriftsartikel (refereegranskat)abstract
- Antibiotic resistance is currently an extensive medical challenge worldwide, with global numbers increasing steadily. Recent data have highlighted wastewater treatment plants as a reservoir of resistance genes. The impact of these findings for human health can best be summarized using a One Health concept. However, the molecular mechanisms impacting resistance spread have not been carefully evaluated. Bacterial viruses, that is bacteriophages, have recently been shown to be important mediators of bacterial resistance genes in environmental milieus and are transferrable to human pathogens. Herein, we investigated the biogeographical impact on resistance spread through river-borne bacteriophages using amplicon deep sequencing of the microbiota, absolute quantification of resistance genes using ddPCR, and phage induction capacity within wastewater. Microbial biodiversity of the rivers is significantly affected by river site, surrounding milieu and time of sampling. Furthermore, areas of land associated with agriculture had a significantly higher ability to induce bacteriophages carrying antibiotic resistance genes, indicating their impact on resistance spread. It is imperative that we continue to analyse global antibiotic resistance problem from a One Health perspective to gain novel insights into mechanisms of resistance spread.
|
|
| 6. |
- Andersson, Tilde, et al.
(författare)
-
Common skin bacteria protect their host from oxidative stress through secreted antioxidant RoxP
- 2019
-
Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9
-
Tidskriftsartikel (refereegranskat)abstract
- Cutibacterium acnes is an abundant skin commensal with several proposed mutualistic functions. A protein with strong antioxidant activity was recently identified from the C. acnes secretome. This protein, termed RoxP, facilitated aerobic bacterial growth in vitro and ex vivo. As reducing events naturally occurred outside of the bacterial cell, it was further hypothesized that RoxP could also serve to modulate redox status of human skin. The biological function of RoxP was here assessed in vitro and in vivo, through oxidatively stressed cell cultures and through protein quantification from skin affected by oxidative disease (actinic keratosis and basal cell carcinoma), respectively. 16S rDNA amplicon deep sequencing and single locus sequence typing was used to correlate bacterial prevalence to cutaneous RoxP abundances. We show that RoxP positively influence the viability of monocytes and keratinocytes exposed to oxidative stress, and that a congruent concentration decline of RoxP can be observed in skin affected by oxidative disease. Basal cell carcinoma was moreover associated with microbial dysbiosis, characterized by reduced C. acnes prevalence. C. acnes's secretion of RoxP, an exogenous but naturally occurring antioxidant on human skin, is likely to positively influence the human host. Results furthermore attest to its prospective usability as a biopharmaceutical.
|
|
| 7. |
- Andersson, Tilde, et al.
(författare)
-
Development of a Molecular Imprinting-Based Surface Plasmon Resonance Biosensor for Rapid and Sensitive Detection of Staphylococcus aureus Alpha Hemolysin From Human Serum
- 2020
-
Ingår i: Frontiers in cellular and infection microbiology. - : Frontiers Media SA. - 2235-2988. ; 10
-
Tidskriftsartikel (refereegranskat)abstract
- Stapylococcus aureus is a common infectious agent in e.g. sepsis, associated with both high mortality rates and severe long-term effects. The cytolytic protein α-hemolysin has repeatedly been shown to enhance the virulence of S. aureus. Combined with an unhindered spread of multi drug-resistant strains, this has triggered research into novel anti virulence (i.e. anti α-hemolysin) drugs. Their functionality will depend on our ability to identify infections that might be alleviated by such. We therefore saw a need for detection methods that could identify individuals suffering from S. aureus infections where α-hemolysin was a major determinant. Molecular imprinted polymers were subsequently prepared on gold coated sensor chips. Used in combination with a surface plasmon resonance biosensor, α-hemolysin could therethrough be quantified from septic blood samples (n = 9), without pre-culturing of the infectious agent. The biosensor recognized α-hemolysin with high affinity (KD = 2.75 x 10-7 M) and demonstrated a statistically significant difference (p < 0.0001) between the α-hemolysin response and potential sample contaminants. The detection scheme proved equally good, or better, when compared to antibody-based detection methods. This novel detection scheme constitutes a more rapid, economical, and user-friendly alternative to many methods currently in use. Heightening both reproducibility and sensitivity, molecular imprinting in combination with surface plasmon resonance (SPR)-technology could be a versatile new tool in clinical- and research-settings alike.
|
|
| 8. |
- Andersson, Tilde, et al.
(författare)
-
Enrichment of antibiotic resistance genes within bacteriophage populations in saliva samples from individuals undergoing oral antibiotic treatments
- 2022
-
Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 13
-
Tidskriftsartikel (refereegranskat)abstract
- Spread of antibiotic resistance is a significant challenge for our modern health care system, and even more so in developing countries with higher prevalence of both infections and resistant bacteria. Faulty usage of antibiotics has been pinpointed as a driving factor in spread of resistant bacteria through selective pressure. However, horizontal gene transfer mediated through bacteriophages may also play an important role in this spread. In a cohort of Tanzanian patients suffering from bacterial infections, we demonstrate significant differences in the oral microbial diversity between infected and non-infected individuals, as well as before and after oral antibiotics treatment. Further, the resistome carried both by bacteria and bacteriophages vary significantly, with blaCTX-M1 resistance genes being mobilized and enriched within phage populations. This may impact how we consider spread of resistance in a biological context, as well in terms of treatment regimes.
|
|
| 9. |
- Baraka, Vito, et al.
(författare)
-
Unveiling Rare Pathogens and Antibiotic Resistance in Tanzanian Cholera Outbreak Waters
- 2023
-
Ingår i: Microorganisms. - 2076-2607. ; 11:10
-
Tidskriftsartikel (refereegranskat)abstract
- The emergence of antibiotic resistance is a global health concern. Therefore, understanding the mechanisms of its spread is crucial for implementing evidence-based strategies to tackle resistance in the context of the One Health approach. In developing countries where sanitation systems and access to clean and safe water are still major challenges, contamination may introduce bacteria and bacteriophages harboring antibiotic resistance genes (ARGs) into the environment. This contamination can increase the risk of exposure and community transmission of ARGs and infectious pathogens. However, there is a paucity of information on the mechanisms of bacteriophage-mediated spread of ARGs and patterns through the environment. Here, we deploy Droplet Digital PCR (ddPCR) and metagenomics approaches to analyze the abundance of ARGs and bacterial pathogens disseminated through clean and wastewater systems. We detected a relatively less-studied and rare human zoonotic pathogen, Vibrio metschnikovii, known to spread through fecal-–oral contamination, similarly to V. cholerae. Several antibiotic resistance genes were identified in both bacterial and bacteriophage fractions from water sources. Using metagenomics, we detected several resistance genes related to tetracyclines and beta-lactams in all the samples. Environmental samples from outlet wastewater had a high diversity of ARGs and contained high levels of blaOXA-48. Other identified resistance profiles included tetA, tetM, and blaCTX-M9. Specifically, we demonstrated that blaCTX-M1 is enriched in the bacteriophage fraction from wastewater. In general, however, the bacterial community has a significantly higher abundance of resistance genes compared to the bacteriophage population. In conclusion, the study highlights the need to implement environmental monitoring of clean and wastewater to inform the risk of infectious disease outbreaks and the spread of antibiotic resistance in the context of One Health.
|
|
| 10. |
- Bläckberg, Anna, et al.
(författare)
-
Lack of Opsonic Antibody Responses to Invasive Infections With Streptococcus dysgalactiae
- 2021
-
Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 12
-
Tidskriftsartikel (refereegranskat)abstract
- Introduction: Streptococcus dysgalactiae can cause severe recurrent infections. This study aimed to investigate antibody responses following S. dysgalactiae bacteraemia and possible development of protective immunity. Materials and Methods: Patients with S. dysgalactiae bacteraemia in the county of Skåne between 2017 and 2018 were prospectively included. Acute and convalescent sera were obtained. All isolates were emm typed and enzyme-linked immunosorbent assay (ELISA) was utilised to analyse specific antibody responses to bacteria and antigens. Bactericidal- and phagocytosis assays were applied to further establish antibody function. Results: Sixteen patients with S. dysgalactiae bacteraemia were included of whom one had recurrent episodes of bacteraemia. Using ELISA with S. dysgalactiae isolates and mutants, development of IgG antibodies was demonstrated in few patients. Type-specific antibodies were demonstrated in one patient when recombinant M proteins as antigens, were applied. The type-specific serum mediated a small increase in phagocytosis but did not facilitate increased killing of the S. dysgalactiae isolate, carrying that M protein, in blood or by phagocytic cells. Conclusion: S. dysgalactiae bacteraemia sometimes results in increased levels of antibodies to the infecting pathogen. We did not find evidence that these antibodies are effectively opsonising. Apparent failure to produce opsonising antibodies might partially explain why S. dysgalactiae can cause recurrent invasive infections in the same host.
|
|
