IMMUNE-RESPONSES AND PROTECTIVE EFFECT IN MICE VACCINATED ORALLY WITH SURFACE SPOROZOITE PROTEIN OF EIMERIA-FALCIFORMIS IN ISCOMS

Immunostimulating complexes (ISCOMs) were built after treatment of a purified surface protein from Eimeria falciformis sporozoites with a palmitic acid derivation, leaning to a high ratio (33-64%) of P27 incorporation in these cage-like structures. P27 kept ifs antigenicity after incorporation in ISCOMs, which induced, after iterative intubations by the oral route to groups of mice, a systemic IgG response, a local IgA response, and a local enhanced cellular response as demonstrated by lymphoproliferation of mesenteric lymph node cells upon in vitro stimulation with antigen. This immunization (120 mu g in six oral doses at a-day intervals) afforded mice a partial protection (60%) against a subsequent 400 oocyst challenge. The reduction in daily oocyst excretion was corroborated by significantly different weight losses between immunized and control mice on days 9 and 10 postinfection and the subsequent death of these control mice. These observations provide the first application of ISCOMs to parasitic intestinal diseases.