Antigen-induced suppression in man: non-specific suppression mediated via OKT8+ cells

We have developed a simple assay for human peripheral-blood suppressor cells induced by soluble protein antigens. Suppressor cells were obtained from 6-day cultures in the presence of tetanus toxoid or PPD and were assayed in co-cultures with fresh autologous PBLs. The proliferative response in this second culture showed significant suppression varying from 50% to 90%. The suppressor cells are OKT8-positive, resistant to X irradiation and non-specific in their function. They do not impede either the function or production of TCGF in the secondary culture but we are unable to detect a non-specific suppressor factor made by these cells.