The role of T cells in immunoglobulin class switching of specific antibody production system in vitro in humans.
Only antibodies of the IgM class were produced in vitro by peripheral blood mononuclear cells stimulated with streptococcal carbohydrate. B cells of the peripheral blood mononuclear cells, however, synthesized both IgM and IgG class antibodies when combined with tonsillar T cells, suggesting that T cells inducing immunoglobulin class switching are present in the tonsils. Peripheral blood T cells also became capable of inducing B cells to produce IgG class antibodies when the T cells were incubated with antigen-pulsed macrophages. Surface IgM-positive, IgG-negative high-density B cells produced IgG antibodies for streptococcal carbohydrate in the presence of these T cells or tonsillar T cells. The culture supernatant solutions from these T cells or tonsillar T cells, however, failed to cause the B cells to produce IgG, indicating that class switching is not mediated by factors released from T cells. Lymphokines such as interleukin-2, human B cell growth factor, helper T cell factor, or interferon-gamma were also incapable of inducing IgG production. These results suggest that the cognate interaction between T cells and B cells is necessary for the immunoglobulin class switching.
Shinomiya
N
N
Laboratories for Phagacytosis Research, National Children's Hospital Medical Research Center, Tokyo, Japan.
Kuratsuji
T
T
Yata
J
J
D000907:Antibodies, Bacterial / Q000096:biosynthesis*; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology*; D002478:Cells, Cultured; D006801:Humans; D007074:Immunoglobulin G / Q000096:biosynthesis; D007132:Immunoglobulin Isotypes / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000096:biosynthesis; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008213:Lymphocyte Activation; D008211:Lymphocyte Cooperation; D008222:Lymphokines / Q000494:pharmacology; D008264:Macrophages / Q000276:immunology; D014066:Palatine Tonsil / Q000166:cytology; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013297:Streptococcus pyogenes / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D008222:Lymphokines; D011135:Polysaccharides, Bacterial