Streptococcal immunoglobulin-binding protein Sib35 exerts stimulatory and mitogenic effects toward mouse B lymphocytes.
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.
Okamoto
Shigefumi
S
Laboratory of Virology and Vaccinology, National Institute of Biomedical Innovation, Ibaraki-Osaka, Japan.
Terao
Yutaka
Y
Tamura
Yasuharu
Y
Hamada
Shigeyuki
S
Kawabata
Shigetada
S
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D051940:B7-2 Antigen / Q000096:biosynthesis; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology* / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D005260:Female; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis; D008213:Lymphocyte Activation; D051379:Mice; D011485:Protein Binding; D013297:Streptococcus pyogenes / Q000276:immunology*
D051940:B7-2 Antigen; D001425:Bacterial Outer Membrane Proteins; D000949:Histocompatibility Antigens Class II; C508570:Sib35 protein, Streptococcus pyogenes