HUMAN LYMPHOCYTES-T GROWN IN T-CELL GROWTH-FACTOR - FUNCTIONAL ATTRIBUTES IN MLC, CML, PLT AND ALLOGENEIC SUPPRESSION

Abstract

Conditions for the production of highly effective human T cell growth factor (TCGF) and its screening in a thymidine [TD] incorporation assay are described. Culture medium supplemented with optimum TCGF concentrations was used in bulk culture systems for the expansion of alloactivated and non-alloactivated T cell populations. Surface marker studies of cells grown in TCGF-dependent culture showed that the majority were T cells expressing [HLA-] DR antigens. These cells retained their proliferative responsiveness in mixed leukocyte cultures [MLC] but were unable to stimulate proliferation of normal allogeneic lymphocytes. Cultured cells which derived from mixed leukocyte cultures retained immunological specificity compared with cells not exposed to TCGF both in terms of proliferative responses caused by allogeneic cells in the absence of TCGF, and in terms of cytotoxic activity against 51Cr-labeled target cells. They were capable of suppression tritiated TD incorporation in MLC. Evidently continuous culture with TCGF can expand a variety of T cell subpopulations with retention of distinct immunological function.