CHOLERA-TOXIN DISCRIMINATES BETWEEN T-HELPER-1 AND T-HELPER-2 CELLS IN T-CELL RECEPTOR MEDIATED ACTIVATION - ROLE OF CAMP IN T-CELL PROLIFERATION

CD4+ T helper (Th) clones can be divided into interleukin 2 (IL2)-secreting Thl and IIr4- secreting Th2 cells. We show in the present report that these two Th subsets have different activation requirements for lymphokine production and proliferation : namely, cholera toxin (CT) as well as forskolin inhibit T cell receptor (TCR)-mediated IL2 production and proliferation in Thl cells, while the same reagents fail to block 114 production and proliferation in Th2 cells. In addition, CT and forskolin differentially influence the proto-oncogene mRNA expression in Thl vs. Th2 cells after stimulation with Con A. Since both reagents lead to elevated levels ofintracellular cAMP, it is likely that Thl and Th2 cells differ in their sensitivity to an increase in CAMP. Our results indicate that the two Th subsets use different transmission signal pathways upon TCR-mediated activation. © 1990, Rockefeller University Press., All rights reserved.