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The Journal of Immunology, Vol 155, Issue 11 5206-5212, Copyright © 1995 by American Association of Immunologists
ARTICLES |
CI Sandborg, KL Imfeld, F Zaldivar Jr, Z Wang, BA Buckingham and MA Berman
University of California, Irvine 92717, USA.
Imbalances in anti-inflammatory and proinflammatory cytokines may be responsible for initiation or progression of diverse pathologic states including autoimmune and infectious diseases. IL-4 production of proinflammatory cytokines and IL-12 promotes differentiation and activation of IFN-gamma-producing T cells, but does a counter- regulatory effect of proinflammatory cytokines on IL-4 production exist? This study evaluates the effect of proinflammatory cytokines (IL- 1 alpha, IL-1 beta, IL-6, IL-12, and TNF-alpha) on IL-4 production in primary human T cell cultures. PBMCs from healthy individuals were tested for IL-4 production in response to PHA and various cytokines. IL- 4 was measured by proliferation of the IL-4-sensitive T cell line (CT.h4S) or ELISA. IL-1 alpha and IL-1 beta inhibited IL-4 production by 20 to 80% in > 92% of healthy individuals (p = 0.0001, paired t- test). IL-12 had an inhibitory effect on PBMC IL-4 production as previously described, but neither IL-6 nor TNF-alpha inhibited IL-4 production. IL-1 had no effect on PHA-induced PBMC or purified T cell proliferation or IL-2 production. IL-4 production by purified T cells stimulated by PHA or the combination of PMA with calcium ionophore (A23187) was inhibited by IL-1, and reconstitution with peripheral blood-derived adherent macrophages had no effect. IL-12 did not inhibit IL-4 production in stimulated purified T cells. Steady state IL-4 mRNA levels were determined by semiquantitative competitive reverse transcribed PCR (RT-PCR). Marked inhibition of IL-4 mRNA levels were seen at 5 h after exposure to IL-1. This interaction between IL-1 and IL-4 may be an important physiologic regulator of the balance between proinflammatory cytokines from activated macrophages and anti- inflammatory cytokines from T cells.
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