Detection, isolation, and functional characterization of two human T-cell subclasses bearing unique differentiation antigens.

Abstract

A heterologous antihuman T[thymus-derived]-cell serum (anti-TH1), raised against purified peripheral T cells and absorbed with an autologous Ig+ [immunoglobulin +] line, was shown to bind specifically to T- but not to B[bone marrow-derived]-lymphoid cells by a complement-dependent cytotoxic assay and by indirect immunofluorescence. Whereas 90% fetal thymocytes and thymocytes were killed by anti-TH1 and complement, a consistently restricted population (50-60%) of peripheral T cells from several normal donors were lysed, indicating that anti-TH1 is directed against 1 or more thymus-specific antigens which are lost or reduced on a subpopulation of human T cells in the periphery. Functional analysis of the unreactive (TH1-) and reactive (TH1+) T-cell subclasses demonstrated that TH1- cells mounted a good proliferative response to a battery of specific soluble antigens (mumps, PPD [purified protein derivative], tetanus toxoid) but neither responded in MLC [mixed lymphocyte culture] nor elaborated LMF [lymphocyte migration factor] in response to tetanus toxoid. In contrast, TH1+ cells proliferated in MLC and elaborated LMF but did not respond by 3H-incorporation to soluble antigens. The relevance of these findings to human T-cell functions in vivo and to previously described functional subclasses of murine T cells is discussed.