| 1. |
- Stegemann-Koniszewski, S, et al.
(författare)
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TLR7 contributes to the rapid progression but not to the overall fatal outcome of secondary pneumococcal disease following influenza A virus infection
- 2013
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Ingår i: Journal of innate immunity. - : S. Karger AG. - 1662-8128 .- 1662-811X. ; 5:1, s. 84-96
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Tidskriftsartikel (refereegranskat)abstract
- Increased risk for bacterial superinfections substantially contributes to the mortality caused by influenza A virus (IAV) epidemics. While the mechanistic basis for this lethal synergism is still insufficiently understood, immune modulation through the viral infection has been shown to be involved. Since the pattern-recognition receptor (PRR) toll-like receptor 7 (TLR7) is a major sensor for the viral genome, we studied how IAV recognition by TLR7 influences the development of secondary pneumococcal infection. In a mouse model of IAV, TLR7-deficient hosts induced a potent antiviral response and showed unchanged survival. In secondary pneumococcal infection during acute influenza, TLR7ko mice showed a fatal outcome similar to wild-type (WT) hosts, despite significantly delayed disease progression. Also, when bacterial superinfection occurred after virus clearance, WT and TLR7-deficient hosts showed similar mortality, even though we found the phagocytic activity of alveolar macrophages isolated from IAV-pre-infected hosts to be enhanced in TLR7ko over WT mice. Thus, we show that a virus-sensing PRR modulates the progression of secondary pneumococcal infection following IAV. However, the fatal overall outcome in WT as well as TLR7ko hosts suggests that processes distinct from TLR7-triggering override the contribution of this single PRR.
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| 2. |
- Kumar, S, et al.
(författare)
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In Vivo Lentiviral Gene Delivery of HLA-DR and Vaccination of Humanized Mice for Improving the Human T and B Cell Immune Reconstitution
- 2021
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Ingår i: Biomedicines. - : MDPI AG. - 2227-9059. ; 9:8
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Tidskriftsartikel (refereegranskat)abstract
- Humanized mouse models generated with human hematopoietic stem cells (HSCs) and reconstituting the human immune system (HIS-mice) are invigorating preclinical testing of vaccines and immunotherapies. We have recently shown that human engineered dendritic cells boosted bonafide human T and B cell maturation and antigen-specific responses in HIS-mice. Here, we evaluated a cell-free system based on in vivo co-delivery of lentiviral vectors (LVs) for expression of a human leukocyte antigen (HLA-DRA*01/ HLA-DRB1*0401 functional complex, “DR4”), and a LV vaccine expressing human cytokines (GM-CSF and IFN-α) and a human cytomegalovirus gB antigen (HCMV-gB). Humanized NOD/Rag1null/IL2Rγnull (NRG) mice injected by i.v. with LV-DR4/fLuc showed long-lasting (up to 20 weeks) vector distribution and expression in the spleen and liver. In vivo administration of the LV vaccine after LV-DR4/fLuc delivery boosted the cellularity of lymph nodes, promoted maturation of terminal effector CD4+ T cells, and promoted significantly higher development of IgG+ and IgA+ B cells. This modular lentigenic system opens several perspectives for basic human immunology research and preclinical utilization of LVs to deliver HLAs into HIS-mice.
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| 3. |
- Sandrock, I, et al.
(författare)
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Genetic models reveal origin, persistence and non-redundant functions of IL-17-producing γδ T cells
- 2018
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Ingår i: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 215:12, s. 3006-3018
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Tidskriftsartikel (refereegranskat)abstract
- γδ T cells are highly conserved in jawed vertebrates, suggesting an essential role in the immune system. However, γδ T cell–deficient Tcrd−/− mice display surprisingly mild phenotypes. We hypothesized that the lack of γδ T cells in constitutive Tcrd−/− mice is functionally compensated by other lymphocytes taking over genuine γδ T cell functions. To test this, we generated a knock-in model for diphtheria toxin–mediated conditional γδ T cell depletion. In contrast to IFN-γ–producing γδ T cells, IL-17–producing γδ T cells (Tγδ17 cells) recovered inefficiently after depletion, and their niches were filled by expanding Th17 cells and ILC3s. Complementary genetic fate mapping further demonstrated that Tγδ17 cells are long-lived and persisting lymphocytes. Investigating the function of γδ T cells, conditional depletion but not constitutive deficiency protected from imiquimod-induced psoriasis. Together, we clarify that fetal thymus-derived Tγδ17 cells are nonredundant local effector cells in IL-17–driven skin pathology.
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