T-CELL REGULATION IN THE PFC RESPONSE OF HUMAN B-CELLs

Abstract

Antibody formation to SRBC activated by PWM was investigated, using human peripheral blood lymphocytes and an immature B-cell line in a system of T-B cell cooperation. Plaque forming cells (PFC) assay was by Cunningham's direct method. T-cell enriched or depleted fractions were obtained by the SRBC rosetting method. follows: 1) High (280±30 PFC) and low (40±8 PFC) responders were found in healthy adult humans. 2) T-B cell cooperation experiments between high and low responders, whose HLA antigen types were completely different, showed that high respondere T-cells (T^h) induced the maturation of low responder B-cells (B^1) to form PFC as well as high responder B-cells (B^h). Low responder T-cells (T^1) induced neither B^h nor B^1 to form PFC. 3) T^h could activate the immature B-cell line to generate PFC, but T^1 could not. We conclude that PWM-inducred antibody production against SRBC in the high and/or low responders is regulated by T-cell functions in vitro.