Effects of Cytokines on Proliferation Responses of Th1 Cells to Mitogen

Ha, Tai You; Lee, Me Yae; Jung, Seung Won

Abstract

Thl cloned cell line 28-4 which is an I-A + KLH - specific Th1 type clone of (C57BU6xC 3H) F1 origin was kindly provided by professor Tomio Tada. In these studies, employing these cloned cells, the author investigated both proliferation responses of Thl cells in the presence of various concentrations of cytokines, such as IL-2, IL-4 or IL-6 and proliferation of Thl cells to various concentration of mitogens such as PHA, ConA or PWM. In addition, the author also investigated the proliferation response of Th1 cells to the optimal dose of PHA, ConA or PWM in the presence or absence of above mentioned cytokines. It was found that IL-2, IL-4 or IL-6 alone their growth stimulation degree was dependent on cytokine concentration and that PHA, ConA or PWM stimulated Thl cell proliferation and optimal dose of PHA ConA and PWM was 3 g, 4 g and 2 g per ml, respectively. In addition, proliferation response of Th1 cells to ConA or PWM in the presence of IL-2 was significantly enhanced, but the proliferation response to PHA was not increased significantly. However, IL-4 did not significantly modulate mitogen-activated Thl cell proliferation response. Interestingly, IL-6 decreased PHA- or ConA-activated proliferation of Thl cells, but did not change PWM-activated proliferation. Taken together, these studies strongly suggested that IL-2, IL-4 or IL-6 itself clone stimulated the Thl cell proliferation and that PHA, ConA or PWM also stimulated Thl cell proliferation. In addition, these studies also indicated that IL-2 increased ConA- or PWM-activated Thl cell proliferation, but IL6 inhibited PHA- or ConA-activated Th1 cell proliferation and that IL-4 did not significantly change the mitogen-activated Th1 cell proliferation.