EARLY MESSAGE EXPRESSION OF INTERLEUKIN-4 AND INTERFERON-GAMMA, BUT NOT OF INTERLEUKIN-2 AND INTERLEUKIN-10, REFLECTS LATER POLARIZATION OFPRIMARY CD4(-CELL CULTURES() T)

The CD4(+) T cell subpopulation identified by the Mel-14(high) phenoty pe represents naive T cells that develop into T helper 1 (Th1) cells u pon stimulation with anti-CD3 and interleukin (IL)-2; however, the add ition of IL-4 induces the development of high IL-4, IL-5 and IL-10-sec reting cells (IL-4 SC). Here, we investigate the timing of cytokine ge ne expression in purified naive, Mel-14(high) CD4(+) T cells after sti mulation under conditions that induce one of three dramatically differ ent populations following secondary stimulation: anti-CD3 + IL-2 (Th1) , anti-CD3 + IL-2 and IL-4 (IL-4 SC) and anti-CD3 + anti-interferon (I FN)-y/anti-IL4 (null population). The skewing toward IL-4 SC developme nt induced by IL-4 in the primary stimulation was clearly visible by 4 0 h. The message for IL-4 was absent at 20 h after stimulation, but wa s induced 30-100-fold by 40 h and was accompanied by a decrease in IFN -gamma message. The message for IL-5 was undetectable. The development of Mel-l4(high) T cells into a Th1 population follows kinetics simila r to those of the development of IL-4 SC in that IFN-gamma gene transc ription was undetectable at 20 h and induced 100-fold by 40 h poststim ulation. This induction was inhibited by the inclusion of anti-LFN-gam ma/anti-IL-4 during the primary stimulation. Finally, IL-10 message is present in both cultures that developed into IL-4 SC and those that d eveloped into Th1 populations, in contrast to the differentiated cultu res where there is a segregation between IL-10 and IFN-gamma expressio n. Undetectable levels of message for both IL-4 and IFN-gamma were see n in the null cultures, which expressed both IL-2 and IL-10 message. T cells identified by the Mel-14(low) phenotype develop into a populati on that secretes high levels of all cytokines tested, and this phenoty pe was revealed within 20 h after stimulation as determined by message analysis. These results demonstrate an early correlation of gene tran scription for IL-4 and IFN-gamma, with the development of IL-4 SC and Th1 cells, and a lack of a correlation at these early time points for expression of IL-2, IL-5 and IL-10.