title: Immunocompetence of normal human appendiceal lymphoid cells: in vitro studies.
abstract: In order to study the activity of immunocompetent lymphocytes in normal human adult mucosal lymphoid tissues in the gut, viable mononuclear cells (MNC) from surgically removed appendices were isolated with a rapid and improved technique, and their immune reactivity determined in vitro. Nearly two-thirds of the isolated cells were B cells, composed of sIgM (30%), sIgA (19%) and sIgG (12%), less than one-third of cells being T cells, composed of OKT4+ helper/inducer T cells (18%) and OKT8+ suppressor/cytotoxic T cells (9%). Isolated B cells were responsive to SAC (Cowan type I Staphylococcus aureus) with marked augmentation of IgG production, but not to lipopolysaccharides (LPS). In the presence or absence of pokeweed mitogen (PWM) and protein A, all isotype-specific Ig production was augmented along with increasing ratios of autologous T cells to B cells, whereas in the presence of anti-HLA-DR antibodies the production of IgA and IgM was reduced to a great extent. Finally, in vitro induction of concanavalin A (Con A)-induced suppressor T (Ts) cells was less than that of helper T (Th) cells. Thus, normal adult appendiceal (Ap) lymphocyte reactivity is predominated by helper T (Th) cells; IgA isotype-specific Ig production appears to be largely regulated by the autoreactive Th subset. This responsiveness to exogenous stimuli may play an important role in the gut mucosal immune responsiveness.
mesh_terms: D000328:Adult; D000942:Antigens, Bacterial / Q000276:immunology; D001065:Appendix / Q000276:immunology*; D001402:B-Lymphocytes / Q000145:classification / Q000276:immunology*; D005260:Female; D006684:HLA-DR Antigens / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000096:biosynthesis / Q000145:classification; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D008934:Mitogens / Q000494:pharmacology; D013601:T-Lymphocytes / Q000145:classification / Q000276:immunology*
chemical_list: D000942:Antigens, Bacterial; D006684:HLA-DR Antigens; D007136:Immunoglobulins; D008934:Mitogens