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. Splenocy tes were stimulated with concanavalin A (ConA) with or without differe nt 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 o f eicosanoids. LTB(4) was not able to induce cytokine secretion by its elf. However, LTB(4) augmented ConA spleen cell production of interleu kin-2 (IL-2) and interferon-gamma (IFN-gamma) from Th-1 cells and inte rleukin-4 (IL-4) and interleukin-10 (IL-10) from Th-2 cells more than the controls treated with ConA alone. The pre-exposition of splenocyte s to LTB(4) for 3 h made these cells more sensitive to ConA in terms o f IL-2 and IL-10 production than those treated with LTB(4) at the onse t of the incubation and maintained during the whole culture period. Th e results suggest that LTB(4) may participate as a component of the si gnal transduction process for ConA-induced Th-1 and Th-2 cytokine prod uction in a time-dependent manner.