Functional analysis of monkey lymphocyte subsets defined by OKT4 and OKT8 Monoclonal Antibodies

Abstract

The percentages of rhesus monkey blood lymphocytes (PBL) reactive with OKT4 and OKT8 antibodies and the OKT4/OKT8 ratio showed significant correlations with the log of the immunoglobulin plaque-forming cell (PFC) response after stimulation with pokeweed mitogen (PWM). These correlations suggested that monkey OKT4+ cells function as "helper" cells and OKT8+ cells function as "suppressor" cells for the PFC response. This was confirmed by separation and study of enriched T- and B-cell subpopulations. OKT8-depleted (OKT4+) and OKT4-depleted (OKT8+) cells were obtained by treatment of purified T cells with antibody and complement. OKT4+ cells augmented the PWM-induced B-cell differentiation into PFC but OKT8+ cells did not. OKT8+ cells suppressed the PFC response by mixtures of B cells and OKT4+ cells. OKT8 antibodies also detected a suppressive cell subset in African green monkeys since the percentage of OKT8+ cells showed a negative correlation with the log PFC response. OKT4 antibodies failed to bind to African green monkey PBL.