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Maslyar, M.

Publications and source records attributed to Maslyar, M..

2 recordsLinked to original sources

Host genetics determines the fate of the Lactobacillaceae population in the small intestine

Whereas innate pattern recognition receptors bind evolutionary conserved moieties shared by diverse groups of microbes, control over closely related microorganisms is likely based on different principles and can be sensitive to genetic variation of the host. While the influence of host genetics on intestinal microbiome composition has been growing in appreciation, understanding of polymorphic mechanisms that regulate individual bacterial lineages requires complex approaches. Using gnotobiotic mouse monocolonized with Ligilactobacillus murinus (ASF361), we found that C57BL/6J (B6) mice harbored significantly more intestinal ASF361 (or other Lactobacillaceae genera) than did BALB/cJ (BALB/c) mice. The difference in ASF361 abundance was independent of adaptive immunity and bacteriotoxic factors. In B6 mice, ASF361 occupied ileal crypts, showed greater expression of adhesion-related molecules, and enriched expression of carbohydrate-metabolism pathways, whereas in BALB/c mice, ASF361 remained largely luminal and enriched expressed genes associated with starvation and stress. These findings highlight the importance of host genetic variation in shaping microbial colonization and suggest that such variation should be considered when evaluating probiotic strains and microbiota transplantation.

microbiology↗

Neuropilin 2 functions as a co-inhibitory receptor to regulate antigen-induced inflammation and allograft rejection

Co-inhibitory receptors function as central modulators of the immune response to resolve T effector activation and/or to sustain immune homeostasis. Here, using humanized SCID mice, we found that NRP2 is inducible on late effector and exhausted subsets of human CD4+ T cells and that it is co-expressed with established co-inhibitory molecules including PD-1, CTLA4, TIGIT, LAG3 and TIM3. In murine models, we also found that NRP2 is expressed on effector memory CD4+ T cells with an exhausted phenotype and that it functions as a key co-inhibitory molecule. Knockout of NRP2 resulted in hyperactive CD4+ T cell responses, and enhanced inflammation in delayed type hypersensitivity and transplantation models. Following cardiac transplantation, allograft rejection and graft failure was accelerated in global as well as CD4+ T cell-specific knockout recipients, and enhanced alloimmunity was dependent on NRP2 expression on CD4+ T effectors, and not on CD4+Foxp3+ T regulatory cells. Also, knockout T regulatory cells were found to be as efficient as wild type cells in the suppression of effector responses in vitro and in vivo. These collective findings identify NRP2 as a novel coinhibitory receptor and demonstrate that its expression on CD4+ T effector cells is of great functional importance in immunity.

immunology↗