Experimental ocular onchocerciasis in cynomolgus monkeys. III. Roles of IgG and IgE antibody and autoantibody and cell-mediated immunity in the chorioretinitis elicited by intravitreal Onchocerca lienalis microfilariae.

Intravitreal injection of small numbers (10-500) of microfilariae (Mf) of Onchocerca lienalis in eyes of cynomolgus monkeys induces posterior segment lesions which resemble those occurring in human onchocerciasis in some respects. In order to determine the potential roles of antibody and cell-mediated immune responses in the formation of these lesions, anti-Onchocerca and anti-retinal IgG and IgE antibody and peripheral lymphocyte blastogenic responses were followed in eight monkeys, for one week to five months after intravitreal injection of Mf. Significant ocular inflammation occurred well before any antibody or peripheral lymphocyte blastogenic responses could be detected. It may be that direct effects of Mf, e.g., by activation of complement via the alternative pathway fulfill important roles in the pathogenesis of the posterior segment lesions.