EFFECT OF EXOGENOUS LEUKOTRIENE B-4 (LTB(4)) ON BALB/C MICE SPLENOCYTE PRODUCTION OF TH-1 AND TH-2 LYMPHOKINES

The effect of exogenous leukotriene B-4 (LTB(4)) on the production of cytokines typical of Th-1 (interleukin-2 and interferon-gamma) and Th-2 (interleukin-4 and interleukin-10) lymphocytes was studied. Splenocytes were stimulated with concanavalin A (ConA) with or without different concentrations of LTB(4) (3 x 10(-10) to 3 x 10(-7) M) for various times in the presence of BW 755C to inhibit the endogenous synthesis of eicosanoids. LTB(4) was not able to induce cytokine secretion by itself. However, LTB(4) augmented ConA spleen cell production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) from Th-1 cells and interleukin-4 (IL-4) and interleukin-10 (IL-10) from Th-2 cells more than the controls treated with ConA alone. The pre-exposition of splenocytes to LTB(4) for 3 h made these cells more sensitive to ConA in terms of IL-2 and IL-10 production than those treated with LTB(4) at the onset of the incubation and maintained during the whole culture period. The results suggest that LTB(4) may participate as a component of the signal transduction process for ConA-induced Th-1 and Th-2 cytokine production in a time-dependent manner.