Patterns of Onchocerca volvulus recombinant antigen recognition in a bovine model of onchocerciasis

The antibody responses of 8 cattle experimentally infected with Onchocerca ochengi to 18 recombinant O. volvulus antigens were measured by ELISA. In a ddition to establishing antigenic cross-reactivity between the species, the dynamics of antigen-specific responses were examined to assess how the rec ognition of the antigens compared to the known stage specificity of express ion. Six cattle responded to all of the antigens and 2 animals responded to all but 1. The dynamics of the recognition of 4 antigens (B20, MOv-2, MOv- 14 and OvNHR2 02E1) were characterized by rapid seroconversion following in fection. Antibody levels to 2 antigens (Ov7 and OvALT-1) increased graduall y over the course of infection. Antibody levels to 4 antigens OvTPX-2, OvL3 Chitinase, Ov103 and Ov9m reached maximum levels coincident with the onset of patency. The levels to 3 antigens (OvProalf C50, OvAldolase, Ov39) varie d little over the course of infection Responses to antigens with functional similarities (OVSOD1, OVSOD2 and OUSOD3 or OvGST1 and OvGST2) showed compa rable temporal profiles. This study demonstrates the high degree of immunol ogical cross-reactivity between the antigens of O. volvulus and O ochengi. The immunogenicity of antigens varied over the course of infection in an an tigen-specific manner, which not always reflected developmentally regulated expression of the corresponding gene, possibly owing to cross-reactive epi topes on distinct parasite products.