IL-2, IL-6, and IFN-γ have distinct effects on the IL-4 plus PMA-induced proliferation of thymocyte subpopulations

Abstract

We have previously reported complex effects of cytokine-containing T cell supernatants on the interleukin (IL)4 plus phorbol 12-myristate 13-acetate (PMA)-induced proliferative response of murine thymocytes. Here we show that recombinant murine IL-2, IL-6, and IFN-γ each differentially regulate the IL-4/PMA-driven growth of thymocyte subpopulations. Thymocytes fractionated into four subpopulations on the basis of CD4 and CD8 expression were stimulated to proliferate by IL-4/PMA. Interferon-γ (IFN-γ) caused almost complete inhibition of the CD4+/CD8- response but had no measurable effect on the growth of CD4-/CD8+ or CD4-/ CD8- populations. This inhibitory effect was also observed on splenic ..