B cell receptor-mediated internalization of salmonella: a novel pathway for autonomous B cell activation and antibody production.
The present paradigm is that primary B cells are nonphagocytosing cells. In this study, we demonstrate that human primary B cells are able to internalize bacteria when the bacteria are recognized by the BCR. BCR-mediated internalization of Salmonella typhimurium results in B cell differentiation and secretion of anti-Salmonella Ab by the Salmonella-specific B cells. In addition, BCR-mediated internalization leads to efficient Ag delivery to the MHC class II Ag-loading compartments, even though Salmonella remains vital intracellularly in primary B cells. Consequently, BCR-mediated bacterial uptake induces efficient CD4(+) T cell help, which boosts Salmonella-specific Ab production. BCR-mediated internalization of Salmonella by B cells is superior over extracellular Ag extraction to induce rapid and specific humoral immune responses and efficiently combat infection.
Souwer
Yuri
Y
Department of Immunopathology, Sanquin Research and Landsteiner Laboratory, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
Griekspoor
Alexander
A
Jorritsma
Tineke
T
de Wit
Jelle
J
Janssen
Hans
H
Neefjes
Jacques
J
van Ham
S Marieke
SM
D000818:Animals; D000917:Antibody Formation / Q000276:immunology*; D017951:Antigen Presentation / Q000276:immunology; D000941:Antigens / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism / Q000648:ultrastructure; D002460:Cell Line; D006801:Humans; D007075:Immunoglobulin M / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation / Q000276:immunology*; D051379:Mice; D008854:Microscopy, Electron; D010587:Phagocytosis / Q000276:immunology; D011947:Receptors, Antigen, B-Cell / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology
D000941:Antigens; D007075:Immunoglobulin M; D011947:Receptors, Antigen, B-Cell