BRUGIA-MALAYI INFECTION IN MICE WITH SELECTIVE SUPPRESSION OF IGE PRODUCTION

For the purpose of evaluating the roles of IgE in helminth infections in vivo, IgE-suppressed mice provide useful models. After infection wi th 50 third-stage larvae of the filarial parasite Brugia malayi, total IgE in BALB/c mice increased to five times higher than uninfected lev els. However, anti-B. malayi IgE antibody was not detected, indicating polyclonal IgE B cell activation by the infection. In BALB/c mice whi ch had received repeated injections of anti-mouse epsilon monoclonal a ntibody from birth and which were subsequently infected, total IgE lev els were less than 10 ng/ml, but anti-B. malayi IgG antibody and total IgA were produced similar to the control. Therefore, IgE-isotype-spec ific suppression was attained. Concerning the protection against B. ma layi, the numbers of fourth-stage larvae and adult worms at 2 and 5 we eks after primary infection, respectively, and fourth-stage larvae at 2 weeks after secondary infection were not significantly different bet ween control and IgE-suppressed mice.