Effect of exposure to benzene on natural killer (NK) cell activity and interleukin-2 (IL-2) production of C57BL/6 mice.

Abstract

To investigate the effect of benzene on murine splenic natural killer (NK) cell activity and interleukin-2 (IL-2) production, we exposed C57 BL/6 mice to benzene for 28 days. Benzene exposure via drinking water at doses of 27 and 154 mg/kg/day yielded the following results. 1) A decrease of spleen cell number was detected on the 14th day of benzene exposure at 154 mg/kg/day, and on the 21st and 28th day of exposure at both 27 mg/kg/day and 154 mg/kg/day. 2) NK activity per viable spleen cell was temporarily enhanced on the 21st day of exposure at doses of 27 and 154 mg/kg/day, thereafter returned to control levels. 3) IL-2 production was inhibited after 28 days of benzene exposure at 27 and 154 mg/kg/day. After ending exposure at doses of 27 mg/kg/day for 28 days, the decreased spleen cell number began to return to control levels from the 14th day on, and reduced IL-2 production returned to control levels. These results suggest that, NK cells are resistant to benzene toxicity, while IL-2 producing cells are sensitive. Thus, an imbalance in immune system was caused by toxic benzene action.