Characterization of human T suppressor‐inducer, ‐precursor and ‐effector lymphocytes in the antigen‐specific plaque‐forming cell response

Abstract
Suppression of an antigen-specific plaque-forming cell response of human blood lymphocytes can be effected by Tμ+ cells that have been primed previously by antigen in vitro for 6 days. While lacking the capacity to suppress the plaque-forming response directly, these primed Tμ+ suppressor-inducer cells stimulate a subpopulation of unprimed Toy cells to differentiate to Tγ+ suppressor-effector cells. The Tμ+, Tγ+ and Tμγ subsets have been shown to be heterogeneous populations of cells. Therefore, the functionally defined T suppressor-inducer, -precursor and -effector cells were characterized by OKT monoclonal antibodies and by the capacity to form rosettes with autologous erythrocytes (ar+). Evidence will be presented that in vitro a T4+μ+ar cell induces a T8+μγ ar+ precursor cell to differentiate to a T8+γ+ar suppressor-effector cell. A similar T suppressor-effector cell can also be isolated directly from peripheral blood of normal donors.