Antigen-specific memory in B-1a and its relationship to natural immunity

• Published in: Proceedings of the National Academy of Sciences - PNAS 2012-04, Vol.109 (14), p.5388-5393
• Main Authors: Yang, Yang, Ghosn, Eliver Eid Bou, Cole, Leah E, Obukhanych, Tetyana V, Sadate-Ngatchou, Patricia, Vogel, Stefanie N, Herzenberg, Leonard A, Herzenberg, Leonore A
• Format: Article
• Language: English
• Subjects: Animals; Antibodies; Antibody formation; Antigens; B lymphocytes; Bacterial Vaccines - administration & dosage; Bacterial Vaccines - immunology; Biological Sciences; Blood donation; blood serum; Cells; Flow Cytometry; Francisella tularensis; Francisella tularensis - immunology; Gram-negative bacteria; Immunity, Innate; Immunization; immunoglobulin G; immunoglobulin M; Immunologic Memory; Inflammation; innate immunity; Lipids; lymphocytes; Memory; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Plasma cells; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Spleen; vaccination
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1121627109

In the companion article by Yang and colleagues [Yang Y, et al. (2012) Proc Natl Acad Sci USA, 109, 10.1073/pnas.1121631109], we have shown that priming with glycolipid (FtL) from Francisella tularensis live-vaccine strain (i) induces FtL-specific B-1a to produce robust primary responses (IgM >>IgG); (ii) establishes persistent long-term production of serum IgM and IgG anti-FtL at natural antibody levels; and (iii) elicits FtL-specific B-1a memory cells that arise in spleen but rapidly migrate to the peritoneal cavity, where they persist indefinitely but divide only rarely. Here, we show that FtL rechallenge alone induces these PerC B-1a memory cells to divide extensively and to express a unique activation signature. However, FtL rechallenge in the context of a Toll-like receptor 4 agonist-stimulated inflammatory response readily induces these memory cells to migrate to spleen and initiate production of dominant IgM anti-FtL secondary responses. Thus, studies here reveal unique mechanisms that govern B-1a memory development and expression, and introduce B-1a memory as an active participant in immune defenses. In addition, at a practical level, these studies suggest previously unexplored vaccination strategies for pathogen-associated antigens that target the B-1a repertoire.