title: The role of T cells in immunoglobulin class switching of specific antibody production system in vitro in humans.
abstract: 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.
authors.affiliation: Laboratories for Phagacytosis Research, National Children's Hospital Medical Research Center, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Shinomiya
authors.forename: T
authors.initials: T
authors.lastname: Kuratsuji
authors.forename: J
authors.initials: J
authors.lastname: Yata
mesh_terms: 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
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007132:Immunoglobulin Isotypes; D007075:Immunoglobulin M; D008222:Lymphokines; D011135:Polysaccharides, Bacterial