INFLUENCE OF ENVIRONMENTAL MITE ANTIGEN ON ANTIMITE ANTIBODY-PRODUCTION IN MICE

To investigate the effects of environmental mite antigen on anti-mite antibody production in mice, a mite-free breeding system was establish ed. The amount of Dermatophagoides farinae (Df) antigen was measured u sing the ELISA inhibition method. Df antigen was detected in the wood- chip bedding used in our conventional breeding system for 1 week (2.55 +/- 0.79 mug/g sample) and 2 weeks (8.96 +/- 3.27 mug/g sample). Df a ntigen was also detected in the standard diet (0.4 mug/g sample) in th e conventional system, whereas no antigen was detected in the case of the mite-free breeding system. Neither anti-Df IgE nor IgG antibody wa s detected before immunization, either in mice raised in the mite-free breeding system or in mice raised in the conventional system. Primary and secondary antibody production after immunizations with 1 or 10 mu g Df antigen was studied in the mouse bred in the conventional and in the mite-free breeding system. Primary anti-Df IgE antibody response o f the conventional group was greater than that in the mite-free group after immunization with either dose of 1 and 10 mug Df antigen. Primar y anti-Df IgG antibody response was greater in the conventional than t he mite-free group after immunization with 1 mug Df antigen. Secondary IgE and IgG responses of the conventional group were greater than the mite-free group after immunizations with 10 mug Df antigen. These res ults suggest that anti-Df antibody production is enhanced by chronic e xposure to Df antigen in the environment.