Pivotal Advance: Peritoneal cavity B-1 B cells have phagocytic and microbicidal capacities and present phagocytosed antigen to CD4+ T cells

Journal of Leukocyte Biology

Yong-An Zhang²  Jun Li²  Daniel R. Barreda  and¹  Aja M. Rieger ¹  J. Oriol Sunyer²  Louise M. Randall²  David Parra²  Christopher A. Hunter² 

[1]  Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA;

关键词: mouse;    phagocytosis;    antigen presentation;    evolution;    particulate;   

DOI  :  10.1189/jlb.0711372

学科分类：生理学

来源: Federation of American Societies for Experimental Biology

【 摘 要 】

Breaking the long-held paradigm that primary B cells are not phagocytic, several studies have demonstrated recently that B cells from fish, amphibians, and reptilians have a significant phagocytic capacity. Whether such capacity has remained conserved in certain mammalian B cell subsets is presently an enigma. Here, we report a previously unrecognized ability of PerC B-1a and B-1b lymphocytes to phagocytose latex beads and bacteria. In contrast, B-2 lymphocytes had an almost negligible ability to internalize these particles. Upon phagocytosis, B-1a and B-1b cells were able to mature their phagosomes into phagolysosomes and displayed the ability to kill internalized bacteria. Importantly, B-1a and B-1b cells effectively present antigen recovered from phagocytosed particles to CD4+ T cells. However, these cells showed a much lower competence to present soluble antigen or antigen from large, noninternalized particles. B-1 B cells presented particulate and soluble antigen to CD4+ T cells more efficiently than macrophages, whereas DCs were the most potent APCs. The novel phagocytic and microbicidal abilities identified in B-1 B lymphocytes strengthen the innate nature that has long been attributed to these cells. In the context of adaptive immunity, we show that these innate immune processes are relevant, as they enable B-1 B cells to present phagocytosable particulate antigen. These capacities position these cells at the crossroads that link innate with adaptive immune processes. In a broader context, these newly identified capacities of B-1 B cells further support the previously recognized functional, developmental, and evolutionary relationships between these cells and macrophages.

【 授权许可】

Unknown