title: Cell suppression in PPD-induced blast specific response of human peripheral blood lymphocytes.
abstract: Secific stimulation of T-cells by PPD was inhibited by their autologous B cells. This inhibition was obtained with B cells separated either by depletion of E-RFC or by elution, with human IgG of lymphocytes bound to Sephadex beads coated with rabbit antibodies anti-human Fab fragments. The suppression was proportional to the number of B cells added to 10(6) T cells incubated with PPD and as previously reported was more marked in the case of B or T cells from BCG-vaccinated subjects with negative skin tests. The suppressive phenomenon required viable B cells and was inhibited by cycloheximide but was not altered by pretreatment of suppressor cells with actinomycin D or colchicine. It seems that B-suppressor cells interfere with recognition of PPD by T cells rather than with the proliferative phase of the specific blast response. Using various surface markers (i.e. Ig, C3 and Fc receptors) it was shown that the suppressor cells represent a subset of Ig-bearing B cells which do not carry Fc receptors.
mesh_terms: D000941:Antigens; D001402:B-Lymphocytes / Q000276:immunology*; D002469:Cell Separation; D003513:Cycloheximide / Q000494:pharmacology; D004306:Dose-Response Relationship, Immunologic; D006801:Humans; D007141:Immunoglobulin Fc Fragments; D007165:Immunosuppression Therapy; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects; D013601:T-Lymphocytes / Q000276:immunology; D013997:Time Factors; D014373:Tuberculin
chemical_list: D000941:Antigens; D007141:Immunoglobulin Fc Fragments; D014373:Tuberculin; D003513:Cycloheximide