Suppression of IgE Antibody Production after Exposure to Ozone in Mice

Abstract

The effect of ozone exposure on IgE antibody production with aerosolized ovalbumin (OA) administration was investigated in Balb/c mice. Mice were continuously exposed to 0.8 ppm ozone for 1, 2, or 4 weeks, respectively, and subsequently aerosolized OA was administered through the respiratory tract for 6 min with a nebulizer. The mice were then immunized intraperitoneally 1 week later with OA. IgE antibody production was suppressed in ozone-exposed mice. However, no significant difference in the primary IgE antibody production by intraperitoneal immunization alone with OA was observed between ozone-exposed mice and nonexposed mice. In order to elucidate the suppressive mechanism of IgE antibody production, hapten-carrier antigenic system was used. It is shown that the induction of helper T cell function was suppressed if the aerosolized carrier protein was administered before intraperitoneal immunization in the mice exposed to ozone. These results suggest that ozone exposure has the effect on the stage of administration of inhaled antigen and the quite insignificant effect on the IgE antibody production after intraperitoneal immunization with OA.