The role of interleukin-2 in T colony formation by human pre-T cells (pTCFC).
Human T lymphocyte colonies may be grown in agar from pre-T peripheral blood cells. Pre-T cells giving rise to these colonies represent 0.5% of the non-adherent, E rosette and Leu 1 depleted mononuclear cell subpopulation. T colony formation is induced by PHA stimulation and only if media conditioned by PHA stimulated peripheral blood lymphocytes (PHA-LCM) is added. These media contained interleukin-2 (IL-2) and T colony promoting activity (TCPA) for pre-T cells. TCPA is co-eluted with IL-2 by gel filtration with an apparent molecular weight of 18,000 daltons. Moreover, when PHA-LCM are absorbed on IL-2-dependent cultured T cells, TCPA is removed as well as IL-2. In attempt to further demonstrate the role of IL-2 in T colony formation by the pre-T cells we used the anti-Tac monoclonal antibody directed against IL-2 receptor. We demonstrated that anti-Tac inhibits T colony formation in a dose-dependent manner in pre-T cells. We conclude that IL-2 is the essential exogenous factor contained in PHA-LCM which allows pre-T cell differentiation expression and proliferation in agar medium.
D000954:Antigens, Surface / Q000032:analysis; D002454:Cell Differentiation; D002455:Cell Division; D002999:Clone Cells / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology
D000954:Antigens, Surface; D007376:Interleukin-2; D010835:Phytohemagglutinins