PRIMARY INVITRO ANTIBODY-RESPONSE FROM HUMAN PERIPHERAL-BLOOD LYMPHOCYTES

Abstract

A method for the induction of a primary in vitro antibody response from human peripheral blood lymphocytes (PBL) is presented. Upon cultivation with trinitrophenyl conjugated polyacrylamide beads (TNP-PAA), an anti-TNP response can be obtained as indicated by the appearance of direct plaque-forming cells from day 5 of culture, with a reproducible peak on day 8. These plaques correspond to cells actively producing antibody of the Ig[immunoglobulin]M type, as shown by their inhibition by cycloheximide and by anti-human IgM serum, but not by anti-human Fc .gamma. serum. Their specificity for the TNP hapten can be demonstrated by the effector cell blockade phenomenon, with highly substituted TNP-human IgG. Although the anti-TNP response induced by TNP-PAA in mouse spleen cell cultures appears T [thymus-derived] cell independent the same response in human PBL may involve the participation of T cells, since E-RFC [erythrocyte rosette forming cells] depletion before culture led to a markedly decreased number of plaque-forming cells. A significant response could be obtained from the PBL of all of the 30 normal individuals tested. The response was reproducible in its magnitude in the 6 individuals tested in at least 3 different experiments. The in vitro stimulation of human PBL by TNP-PAA can be proposed as a reliable test for the study of human B [bone marrow-derived] cell function in specific primary antibody response.