Open AccessStreptococcal immunoglobulin‐binding protein Sib35 exerts stimulatory and mitogenic effects toward mouse B lymphocytes
Author(s) -
Okamoto Shigefumi,
Terao Yutaka,
Tamura Yasuharu,
Hamada Shigeyuki,
Kawabata Shigetada
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01078.x
Subject(s) - antibody , microbiology and biotechnology , b cell , biology , immunoglobulin class switching , streptococcus , immunoglobulin g , binding protein , immunoglobulin fc fragments , protein g , chemistry , immunology , biochemistry , bacteria , gene , genetics
Group A Streptococcus (GAS) produces several immunopotent proteins such as the immunoglobulin‐binding protein 35 (Sib35) family, known to be an immunoglobulin G‐degrading enzyme of GAS and a CD16‐binding protein of GAS, Mac‐1‐like protein/IdeS. In this study, Sib35 activated mouse B cells and induced the proliferation of B lymphocytes, while it also bound directly to B cells, which enhanced the expression of MHC class II and B7‐2. Furthermore, Sib35 induced the differentiation of B cells to immunoglobulin‐producing plasma cells and B cell line proliferation. These results suggest that Sib35 functions as a streptococcal mitogen of mouse B cells.