Adoptive transfer of delayed hypersensitivity and protective immunity to Eimeria tenella with chicken-derived...

Delayed hypersensitivity (DH) and protective immunity were transferred to nonimmune 4- and 10-week-old broiler chickens with transfer factor (TF) prepared from splenic leukocytes of chickens immunized with CocciVac D. Only chickens injected with the immune TF showed DH by wattle reaction to oocyst antigen and protective immunity to Eimeria tenella challenge infection. Chickens given a single injection of TF 5 days before challenge infection exhibited a significant (P less than .05) DH response at the time of infection. Immune TF preparations were active at concentrations of 100, 200, or 400 mg. Neither DH nor protective immunity was transferred to chickens injected with the TF-diluent control or nonimmune TF. The nonimmune TF was prepared from chickens kept free of coccidial infection. These findings indicated that TF prophylaxis produced beneficial results in nonimmune chickens by conferring some protection against challenge with E. tenella. The effects of TF on T-lymphocyte mediated protective immunity to coccidia in chickens are discussed.