MITOGEN-INDUCED LYMPHOCYTE-PROLIFERATION AND INTERFERON-PRODUCTION FOLLOWING COCCIDIA INFECTION

Concanavalin A-induced lymphocyte proliferation and interferon production were measured following infection with Eimeria acervulina in lines of chickens congenic at the major histocompatibility complex and in two unrelated lines. Similar proliferation responses were seen for splenic and peripheral blood lymphocytes following primary but not secondary infection. Greater differences in lymphocyte proliferation were found between the congenic lines and unrelated lines than among the congenic lines. The congenic lines had very low responses to Con A, in terms of both lymphocyte proliferation and interferon production. At some times after infection, background proliferation in all lines was higher for infected than uninfected chickens, which was probably an indication of activated lymphocytes in the circulation. Mitogen-induced lymphocyte proliferation and interferon production, although clearly affected by coccidial infection, were not reflective of severity of infection.