Developmental changes in humoral suppressor activity released from concanavalin A-stimulated human lymphocytes on B cell differentiation.
Cell-free culture supernatants (Con A-activated supernatants) were obtained by incubating peripheral blood lymphocytes (PBL) from cord blood, healthy children of various ages, and healthy adults with mitogenic doses of concanavalin A (Con A) for 48 hr. It is well known that human T lymphocytes are activated by Con A to manifest suppressor function in vitro. One mechanism whereby these suppressor cells act has been shown to be by the secretion of a soluble suppressor factor. The present study has investigated the Con A-inducible suppressor cell function in cord blood, children of various ages, and adults by comparing the ability of each Con A-activated supernatant to inhibit the generation of immunoglobulin-producing cells (Ig-PC) in pokeweed mitogen- (PWM) stimulated cultures of adult PBL. Con A-activated supernatants from adults could markedly suppress the generation of Ig-PC by allogeneic as well as autologous PBL in response to PWM. Such suppression appeared to be equally effective on the generation of IG-PC of 3 major classes, IgG, IgM, and IgA. On the contrary, Con A-activated supernatants from cord blood and newborn infants showed only a negligible suppression on PWM-induced adult B cell differentiation. But the suppressor activity found in Con A-activated supernatants gradually increased with advancing age, and reached approximately to the adult level at 4 yr of age or later. The results suggest that human T lymphocytes may be relatively deficient in their Con A-induced suppressor cell function in the early period of life.
D000328:Adult; D000375:Aging; D000917:Antibody Formation; D000921:Antibody-Producing Cells / Q000276:immunology; D001402:B-Lymphocytes / Q000166:cytology; D002454:Cell Differentiation; D002648:Child; D002675:Child, Preschool; D003208:Concanavalin A / Q000494:pharmacology*; D003602:Cytotoxicity, Immunologic; D005312:Fetal Blood / Q000276:immunology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008214:Lymphocytes / Q000276:immunology*; D011043:Pokeweed Mitogens / Q000494:pharmacology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
D011043:Pokeweed Mitogens; D003208:Concanavalin A