title: Novel functions of murine B1 cells: active phagocytic and microbicidal abilities.
abstract: B1 cells are evolutionarily conserved innate-like cells that share many features with macrophages. It has also been established that B1 cells have a close developmental relationship with macrophages. However, whether B1 cells are able to act as professional phagocytic cells is not clear. In this study, we report that mouse peritoneal cavity (PerC) B cells demonstrate in vivo and in vitro phagocytic activities for Staphylococcus aureus, Escherichia coli, and polystyrene fluorescent microspheres. Approximately 5% of PerC B cells, mainly B1b cells, showed phagocytic activity. Ingested microbes were killed efficiently in the phagolysosome. The antigen-specific B-cell antigen receptor promoted B-cell phagocytosis, resulting in antigen presentation to T cells after uptake of bacteria. Our results reveal for the first time that mouse B1 cells have active phagocytic capabilities and thereby act as a bridge linking innate and adaptive immunity.
authors.affiliation: Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an, PR China.
authors.forename: Jixin
authors.initials: J
authors.lastname: Gao
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Ma
authors.forename: Weijie
authors.initials: W
authors.lastname: Gu
authors.forename: Meng
authors.initials: M
authors.lastname: Fu
authors.forename: Jingang
authors.initials: J
authors.lastname: An
authors.forename: Ying
authors.initials: Y
authors.lastname: Xing
authors.forename: Tianwen
authors.initials: T
authors.lastname: Gao
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Yufeng
authors.initials: Y
authors.lastname: Liu
mesh_terms: D056704:Adaptive Immunity / Q000276:immunology*; D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D004926:Escherichia coli / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology*; D017737:Macrophages, Peritoneal / Q000276:immunology*; D051379:Mice; D010587:Phagocytosis / Q000276:immunology*; D010588:Phagosomes / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology; D013211:Staphylococcus aureus / Q000276:immunology*
chemical_list: D011947:Receptors, Antigen, B-Cell