Immunoprophylactic effect of synthetic polypeptide vaccine derived from Theileria sergenti merozoite

Theileria sergenti merozoite부터 합성한 polypeptide vaccine의 예방효과 연구

Eighteen holstein-calves(4~5 months old) in a divided groups including the matched control were immunized with $100{\mu}g/dose$ of 34kDa, 45kDa polypeptide and T sergenti merozoite vaccine(protein content $100{\mu}g/dose$) respectively, previously mixed with aluminium hydroxide to elicit antibodies. All groups of calves were boosted with same dose and intervals. The animals were challenged by tick infestations in the endemic pasture of theileriosis from March to September 1994. The animals were monitored for the erythrocyte count, parasitemia, hematocrit and the specific antibody reactions elicited by immunization. The immunological responses demonstrated that vaccination with 34kDa polypeptide and T sergenti merozoite derived vaccine inhibited to produce the 75kDa band immunological responds even in the vaccinated calves after being challenged by tick infestations in the pasture. However, the specific antibody reactions were detected at the 32kDa band in the nonimmunized calves and T sergenti merozoite derived vaccine by the western blot. The 34kDa polypeptide vaccine and T sergenti merozoite derived vaccine were evaluated to be able to protect inducing anemia and to decrease parasitemias level. These vaccines have the efficacy of inhibition to produce a certain antigen corresponding 75kDa band antigen of parasite in the calves as challenged with tick infestations.