Cell-mediated and humoral immunity in sheep exposed to bovine immunodeficiency-like virus

Six sheep were transfused intraperitoneally with whole blood from two sheep chronically infected with the bovine immunodeficiency-like virus (BIV). Five sheep were transfused intraperitoneally (i.p.) with normal ovine whole blood and served as controls. Five of six BIV-inoculated sheep seroconverted; four were transiently seropositive while one remained seropositive for the duration of the experiment. Tests for nonspecific lymphocyte reactivity to mitogens were performed monthly for one year. At approximately 10 months postinoculation, all sheep were immunized with chicken ovalbumin, canine red blood cells, and tuberculin. There were no significant associations between BIV exposure and deficits in antibody production to chicken ovalbumin and canine red blood cells; nonspecific lymphoproliferative responses to concanavalin-A, lipopolysaccharide, and pokeweed mitogen; specific lymphoproliferative responses to ovalbumin and tuberculin purified protein derivative; or cutaneous delayed type hypersensitivity to tuberculin purified protein derivative. Exposure to BIV did not alter the humoral or cell mediated immune responses of sheep in the first year of exposure.