| 1. |
- Apcher, Sebastien, et al.
(författare)
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mRNA translation from an antigen presentation perspective: A tribute to the works of Nilabh Shastri
- 2022
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 141, s. 305-308
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Forskningsöversikt (refereegranskat)abstract
- The field of mRNA translation has witnessed an impressive expansion in the last decade. The once standard model of translation initiation has undergone, and is still undergoing, a major overhaul, partly due to more recent technical advancements detailing, for example, initiation at non-AUG codons. However, some of the pioneering works in this area have come from immunology and more precisely from the field of antigen presentation to the major histocompatibility class I (MHC-I) pathway. Despite early innovative studies from the lab of Nilabh Shastri demonstrating alternative mRNA translation initiation as a source for MHC-I peptide substrates, the mRNA translation field did not include these into their models. It was not until the introduction of the ribo-sequence technique that the extent of non-canonical translation initiation became widely acknowledged. The detection of peptides on MHC-I molecules by CD8 + T cells is extremely sensitive, making this a superior model system for studying alternative mRNA translation initiation from specific mRNAs. In view of this, we give a brief history on alternative initiation from an immunology perspective and its fundamental role in allowing the immune system to distinguish self from non-self and at the same time pay tribute to the works of Nilabh Shastri.
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| 2. |
- Bahrami, F., et al.
(författare)
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Blood transcriptional profiles distinguish different clinical stages of cutaneous leishmaniasis in humans
- 2022
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890. ; 149, s. 165-173
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Tidskriftsartikel (refereegranskat)abstract
- Cutaneous leishmaniasis (CL) is a neglected tropical disease with severe morbidity and socioeconomic sequelae. A better understanding of underlying immune mechanisms that lead to different clinical outcomes of CL could inform the rational design of intervention measures. While transcriptomic analyses of CL lesions were recently reported by us and others, there is a dearth of information on the expression of immune-related genes in the blood of CL patients. Herein, we investigated immune-related gene expression in whole blood samples collected from individuals with different clinical stages of CL along with healthy volunteers in an endemic CL region where Leishmania (L.) tropica is prevalent. Study participants were categorized into asymptomatic (LST+) and healthy uninfected (LST-) groups based on their leishmanin skin test (LST). Whole blood PAXgene samples were collected from volunteers, who had healed CL lesions, and patients with active L. tropica cutaneous lesions. Quality RNA extracted from 57 blood samples were subjected to Dual-color reverse-transcription multiplex ligation-dependent probe amplification (dcRT-MLPA) assay for profiling 144 immune-related genes. Results show significant changes in the expression of genes involved in interferon signaling pathway in the blood of active CL patients, asymptomatics and healed individuals. Nonetheless, distinct profiles for several immune-related genes were identified in the healed, the asymptomatic, and the CL patients compared to the healthy controls. Among others, IFI16 and CCL11 were found as immune transcript signatures for the healed and the asymptomatic individuals, respectively. These results warrant further exploration to pinpoint novel blood biomarkers for different clinical stages of CL.
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| 3. |
- Bettoni, Serena, et al.
(författare)
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Serum complement activation by C4BP-IgM fusion protein can restore susceptibility to antibiotics in Neisseria gonorrhoeae
- 2022
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 141, s. 215-215
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Background: The sexually transmitted infection gonorrhea is a common health problem worldwide causing critical reproductive sequelae such as infertility. An effective vaccine remains elusive and antibiotics used in clinics are becoming ineffective because of the rapid spread of resistance among Neisseria gonorrhoeae, the causative organism of gonorrhea. We previously created a human fusion protein called C4BP-IgM to mark and eliminate bacteria by activating host complement. C4BP-IgM links the two N-terminal domains of C4BP, which bind to gonococci, with the Fc domain of IgM to increase complement activation on and kill bacteria. We documented that C4BP-IgM enhances bactericidal activity of serum against clinical C4BP-binding gonococcal isolates from patients, and markedly attenuated the duration and burden of gonococcal infection in a mouse vaginal colonizationmodel 1. Here, we explore the activity of C4BP-IgM as an adjuvant to several antibiotics (spectinomycin, azithromycin, cefixime, ceftriaxone and ciprofloxacin) currently or previously used to treat gonorrhea.Materials and methods: Cooperative bactericidal activity between C4BP-IgM, complement and antibiotics was evaluated by monitoring survival and membrane alterations of a laboratory isolate and two clinical azithromycin-resistant gonococcal strains, which also resisted killing by normal human serum. Effect of complement and C4BP-IgM on uptake and intracellular activity of selected antibiotics was also assessed.Results: We found that human serum, as source of complement components, reduced MIC values of antibiotics against N. gonorrhoeae. Addition of C4BP-IgM at concentrations which only partially reduced survival, induced complete killing of bacteria when both serum and antibiotics were present. Bactericidal cooperation between complement and antimicrobials was revealed to be triggered by membrane damage induced by C4BP-IgM complement activation. Formation of membrane attack complex pores on bacteria facilitated uptake of antimicrobials, which in turn enhanced their intracellular concentration and activity. Remarkably, C4BP-IgM restored susceptibility to azithromycin of two azithromycin-resistant clinical gonococcal strains that overexpressed the MtrC-MtrD-MtrE efflux pump.Conclusion: We provide proof-of-principle for the use of C4BP-IgM fusion protein as an adjuvant to antibiotics, which could be re-purposed for clinical use pending the development of effective new treatments.
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| 4. |
- Chaban, Viktoriia, et al.
(författare)
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Escherichia coli-induced inflammatory responses are temperature-dependent in human whole blood ex vivo
- 2023
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 157, s. 70-77
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Tidskriftsartikel (refereegranskat)abstract
- Systemic inflammatory conditions are often associated with hypothermia or hyperthermia. Therapeutic hypothermia is used in post-cardiac arrest and some other acute diseases. There is a need for more knowledge concerning the effect of various temperatures on the acute inflammatory response. The complement system plays a crucial role in initiating the inflammatory response. We hypothesized that temperatures above and below the physiologic 37 & DEG;C affect complement activation and cytokine production ex vivo. Lepirudin-anticoagulated human whole blood from 10 healthy donors was incubated in the presence or absence of Escherichia coli at different temperatures (4 & DEG;C, 12 & DEG;C, 20 & DEG;C, 33 & DEG;C, 37 & DEG;C, 39 & DEG;C, and 41 & DEG;C). Complement activation was assessed by the terminal C5b-9 complement complex (TCC) and the alternative convertase C3bBbP using ELISA. Cytokines were measured using a 27-plex assay. Granulocyte and monocyte activation was evaluated by CD11b surface expression using flow cytometry. A consistent increase in complement activation was observed with rising temperature, reaching a maximum at 41 & DEG;C, both in the absence (C3bBbP p < 0.05) and presence (C3bBbP p < 0.05 and TCC p < 0.05) of E. coli. Temperature alone did not affect cytokine production, whereas incubation with E. coli significantly increased cytokine levels of IL-18, IL-2, IL-6, IL-8, IFN-& gamma;, and TNF at temperatures > 20 & DEG;C. Maximum increase occurred at 39 & DEG;C. However, a consistent decrease was observed at 41 & DEG;C, significant for IL-18 (p = 0.003). Granulocyte CD11b displayed the same temperature-dependent pattern as cytokines, with a corresponding increase in endothelial cell apoptosis and necrosis. Thus, blood temperature differentially determines the degree of complement activation and cytokine release.
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| 5. |
- Fiúza Rosa, Fábio, et al.
(författare)
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Direct Reprogramming of Mouse and Human Fibroblasts into Conventional Dendritic Cells Type 1
- 2022
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Ingår i: Molecular Immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 150, s. 22-22
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Konferensbidrag (refereegranskat)abstract
- Cell fate reprogramming of adult cells towards pluripotency or unrelated somatic cell-types has been explored in the context of regenerative medicine. Dendritic cells (DCs) are professional antigen presenting cells (APCs) specialized in the recognition, processing and presentation of antigens to T-cells, inducing adaptive immunity. In particular, the mouse conventional DCs type 1 (cDC1) subset or DC1 human equivalent excel on the ability to perform antigen cross-presentation, a critical step for inducing cytotoxic responses. We hypothesized that the unique properties of cDC1s could be induced in unrelated cell-types, allowing the direct control of immune responses with cell reprogramming.Here, the requirements to induce cDC1s were investigated using combinatorial overexpression of Transcription Factors (TFs) in Clec9a-tdTomato mouse fibroblasts. In the hematopoietic system, Clec9a specifically marks the DC lineage, including all conventional dendritic cells type 1 (cDC1). We have identified PU.1, IRF8 and BATF3 (PIB) as sufficient and necessary to induce Clec9a reporter activation, establish DC morphology and activate a cDC1 transcriptional program in mouse fibroblasts. The over- expression of PIB ignites the expression of DC markers including CD103, XCR1, MHC-I, MHC-II and co-stimulatory molecules. Functionally, Induced DCs (iDCs) secrete inflammatory cytokines and engulf, process, present and cross-present antigens to CD4+ and CD8+ T cells, respectively. Additionally, we have demonstrated that combined expression of PIB factors induces DC1 reprogramming in human fibroblasts. Human iDC1s acquire DC morphology, express DC1 markers, including Clec9a, CD141 and the co-stimulatory molecules CD40, CD80 and CD86, and acquire a DC1 transcriptional signature at the single cell level. Interestingly, DC1 reprogramming efficiency can be enhanced 70-fold by supplementing culture media with inflammatory cytokines, suggesting a regulatory role of inflammation during DC1 reprogramming.Hence, we provide evidence that antigen presentation and cross-presentation can be dynamically programmed by a small combination of TFs. These findings provide insights into cDC1 specification and a platform for developing cancer immunotherapies based on cell reprogramming.
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| 6. |
- Grundström, Christine, et al.
(författare)
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The transcription factor E2A can bind to and cleave single-stranded immunoglobulin heavy chain locus DNA
- 2023
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Ingår i: Molecular Immunology. - : Elsevier. - 0161-5890 .- 1872-9142. ; 153, s. 51-59
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Tidskriftsartikel (refereegranskat)abstract
- Class switch recombination (CSR) changes the constant region of the immunoglobulin heavy chain (IgH), and somatic hypermutation (SH) introduces point mutations in the variable regions of the antibody genes. Both these processes that optimize antibody responses of B lymphocytes are initiated by the enzyme Activation Induced cytidine Deaminase (AID). Here we have searched for CSR or SH coupled activities of the transcription factor E2A, since E2A is in a complex with AID and the transcription factors PAX5, ETS1 and IRF4 on key sequences of the Igh locus in B lymphocytes activated to CSR and SH. We report that E2A in contrast to other described transcription factors binds sequence specifically also to single-stranded DNA. The binding of E2A to single-stranded DNA has a strong sequence preference for one strand of a site in the intronic enhancer of the Igh locus. Furthermore, E2A was also found to cleave single-stranded DNA. The sequence profile of substrates cleaved by E2A is coupled to the sequences of substrates and products of AID, suggesting that E2A has a role not only in targeting of AID to switch regions and SH parts of antibody genes but also in cleavage of DNA at these sites.
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| 7. |
- Houtman, Miranda, et al.
(författare)
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Five commercially-available antibodies react differentially with allelic forms of human HLA-DR beta chain
- 2022
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890 .- 1872-9142. ; 152, s. 106-110
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Tidskriftsartikel (refereegranskat)abstract
- Allelic variants of HLA-DRB1 have been associated with a variety of autoimmune and infectious diseases. Although the precise molecular mechanisms by which HLA-DRB1 alleles predispose to a particular disease are currently unclear, it has been shown that mRNA expression levels of HLA-DRB1 are dependent on the different alleles. We aimed to measure HLA-DR beta chain levels in peripheral blood mononuclear cells of individuals carrying HLA-DRB1*03:01/*04:01 and HLA-DRB1*03:01/*15:01 alleles by western blotting, using five commercially-available HLA-DRB antibodies. We observed highly heterogeneous binding of the tested antibodies to the different allelic forms of the HLA-DR beta chain. Overall, we show that current immunological research that employs available antibodies to detect HLA-DR beta chains is biased towards detection of specific variants of the protein; this may cause significant discrepancy in quantification of protein expression in a heterogeneous human population.
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| 8. |
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| 9. |
- Langwiński, Wojciech, et al.
(författare)
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Allergic inflammation in lungs and nasal epithelium of rat model is regulated by tissue-specific miRNA expression
- 2022
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Ingår i: Molecular Immunology. - : Elsevier BV. - 0161-5890. ; 147, s. 115-125
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Atopic asthma and allergic rhinitis are common chronic inflammatory diseases affecting lower airways and nasal mucosa, respectively. Several reports demonstrated frequent co-occurrence of these two diseases, however, the exact molecular mechanism has not been described. The present study aimed to investigate if small non-coding RNA might be responsible for the co-occurrence of asthma and allergic rhinitis in an animal model of allergic airway inflammation. Materials and methods: As an in vivo model of allergic airway inflammation, we used Brown Norway rats exposed intranasally to house dust mite (HDM). Histological analysis, total IgE concentration, eosinophil counts and iNOS gene expression were determined to confirm inflammatory changes. Small RNA sequencing in the lung tissue and nasal epithelium was performed with TruSeq Small RNA Library Preparation Kit and analyzed using the BaseSpace tool. Validation of sequencing results was performed using qPCR. To assess the functional role of hsa-miR-223–3p, we transfected normal human bronchial epithelial (NHBE) cells with specific LNA-inhibitor and measured phosphorylated protein level of NF-kB with ELISA. Expression analysis of NF-kB pathway-related genes was performed using qPCR with SYBR Green and analyzed in DataAssist v3.01. Statistical analysis were done with STATISTICA version 13. Results: We found 9 miRNA genes differentially expressed in the lungs of allergic rats. In nasal epithelium, only rno-miR-184 was upregulated in animals exposed to HDM. Validation with qPCR confirmed increased expression only for rno-miR-223–3p in the lungs from allergic rats. The expression of this miRNA was also increased in normal bronchial epithelial ALI cell culture stimulated with IL-13, but not in cells cultured in monolayer due to the low mRNA level of IL13RA1 and IL13RA2. Transfecting NHBE cells with hsa-miR-223–3p inhibitor increased the amount of phosphorylated NF-kB protein level and expression of MUC5AC, CCL24 and TSLP genes. Conclusions: These findings suggest that miRNAs that regulate allergic inflammation in the lungs and nasal epithelium are specific for upper and lower airways. Furthermore, our study provides new insight on the role of hsa-miR-223–3p, that via targeting NF-kB signaling pathway, regulates the expression of MUC5AC, CCL24 and TSLP. Taken together, our study suggests that miR-223–3p is a regulator of allergic inflammation and could potentially be used to develop novel and targeted therapy for asthma.
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| 10. |
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