Separation of functional subsets of human T cells by a monoclonal antibody.

TLDR

The authors generated the monoclonal antibody OKT4, which binds 55–60 % of peripheral blood T cells but not B cells, null cells, or macrophages, and used cell‑sorting to separate OKT4⁺ and OKT4⁻ subsets that proved functionally distinct. OKT4⁻ cells contain the TH2⁺ cytotoxic/suppressor subset, while OKT4⁺ cells act as helper cells; both subsets proliferate with mitogens, but only OKT4⁺ respond to soluble antigens and only OKT4⁻ become cytotoxic after alloantigen sensitization, and both are required for optimal cytotoxic development, making OKT4 a valuable reagent for studying functional T‑cell subsets.

Abstract

A monoclonal antibody was produced to human peripheral blood T cells. This hybridoma antibody, termed OKT4, was reactive by indirect immunofluorescence with only 55-60% of the peripheral blood T cell population (OKT4+) and unreactive with normal B cells, null cells, and macrophages. The OKT4- T cell population contained the previously described TH2+ subset that has been shown to contain cytotoxic/suppressor cells. With cell-sorter separation of OKT4+ and OKT4- cells, it was shown that these T cell subsets were functionally discrete. Both gave proliferative responses with concanavalin A, alloantigens, and phytohemagglutinin although OKT4+ cells were much more responsive to the latter. OKT4+ cells alone responded to soluble antigens whereas OKT4- cells alone were cytotoxic after alloantigenic sensitization of unfractionated T cells. However, both OKT4+ and OKT4- cells were required during sensitization for optimal development of cytotoxicity. These data suggest that the OKT4+ subset represents a helper population and that the OKT4- subset contains the cytotoxic effector population. OKT4 could be a valuable reagent for determining alterations of these functional subsets in human diseases.