Abstract
The effects of chicken anti-Eimeria tenella serum on the in vitro Phagocytosis of sporozoites and merozoites of E. tenella by chicken peritoneal macrophages were investigated. The phagocytic activity of macrophages was enhanced 30 to 120 min after inoculation of the parasites, when the 20% heat-inactivated immune serum was added to the medium. These effects were suppressed by the addition of papain fragments of rabbit IgG to chicken IgG into the medium. By the treatment with fresh immune serum, however, the number of the parasites ingested by macrophages did not increase during the observation period from 30 to 120 min after inoculation. The effects of various types of sera on the fate of sporozoites taken in macrophages were shown only in macrophages treated with fresh immune serum. In this group, the number of sporozoites contained in macrophages 2 hr after incubation was fewest compared with those of the other groups treated with heat-inactivated immune, heat-inactivated normal, and fresh normal sera, and the reduction rate of the parasites from 2 to 15 hr after incubation was higher than those of the other groups. The reduction rates of the parasites in the groups treated with heat-inactivated immune serum and normal serum were similar. These phenomena may be due to the effects of cytolytic action with complements and antibodies, resulting in complete or partial lysis of the parasites within a short period of time.