Characterisation of Ostertagia ostertagi antigens by the different bovine immunoglobulin isotypes.

ABSTRACT

Antigenic differences between the developmental stages of Ostertagia ostertagi were studied by SDS-PAGE and Western blotting. Gel electrophoresis showed a complex protein pattern different for every stage with the O ostertagi fourth stage larvae (L4) showing an intermediate protein pattern between the third stage larvae (L3) and the adult stage. Immunoblotting showed that IgG1, IgG2 and IgM immunoglobulins present in serum from uninfected calves identified several O ostertagi antigens at every stage. When using serum from O ostertagi infected calves, O ostertagi specific IgG1 was the predominant bovine immunoglobulin. Specific IgG2 and IgM responses were also observed, while specific IgA antibodies were hardly detectable. Severe IgG1 cross reactivity was demonstrated when using anti-Cooperia oncophora serum.