Germ-free mice exhibit profound immunological immaturity.Despite recent studies emphasizing the role of specific bacterium-derived metabolites in immune cell development and differentiation,the mechanisms linking micr...Germ-free mice exhibit profound immunological immaturity.Despite recent studies emphasizing the role of specific bacterium-derived metabolites in immune cell development and differentiation,the mechanisms linking microbiota absence to systemic immune deficits remain incompletely defined.Here,droplet-based single-cell RNA sequencing of bone marrow and peripheral blood from both germ-free and specific pathogen-free mice was performed,identifying 25 transcriptionally distinct cell types.Neutrophil apoptosis was elevated in germ-free mice,potentially due to the absence of niacin dehydrogenase,a metabolite primarily produced by Pseudomonas.In addition,germ-free mice exhibited increased excretion of 5’-methylthioadenosine,enhanced ERK activation driven by reactive oxygen species,and disruption of bone marrow stromal antigen 2 signaling.Monocytes and CD8^(+)T cells from germ-free mice showed diminished responses to interferon-β and interferon-γ,consistent with heightened viral susceptibility.These findings establish a microbiota-dependent regulatory pathway linking immunodeficiency to microbial absence in germ-free mice,confirmed through complementary validation techniques.展开更多
基金supported by the Science Technology and Innovation Commission of Shenzhen Municipality,China(SGCX20190919142801722)。
文摘Germ-free mice exhibit profound immunological immaturity.Despite recent studies emphasizing the role of specific bacterium-derived metabolites in immune cell development and differentiation,the mechanisms linking microbiota absence to systemic immune deficits remain incompletely defined.Here,droplet-based single-cell RNA sequencing of bone marrow and peripheral blood from both germ-free and specific pathogen-free mice was performed,identifying 25 transcriptionally distinct cell types.Neutrophil apoptosis was elevated in germ-free mice,potentially due to the absence of niacin dehydrogenase,a metabolite primarily produced by Pseudomonas.In addition,germ-free mice exhibited increased excretion of 5’-methylthioadenosine,enhanced ERK activation driven by reactive oxygen species,and disruption of bone marrow stromal antigen 2 signaling.Monocytes and CD8^(+)T cells from germ-free mice showed diminished responses to interferon-β and interferon-γ,consistent with heightened viral susceptibility.These findings establish a microbiota-dependent regulatory pathway linking immunodeficiency to microbial absence in germ-free mice,confirmed through complementary validation techniques.
