Infection with vaccinia favors the selection of hybridomas synthesizing autoantibodies against intermediate filaments, one of them cross-reacting with the virus hemagglutinin.

Immunization of mice with lysates from infected cells and pure vaccinia virus generated hybridomas, a large fraction of which make autoantibodies binding to intermediate filaments (greater than IF) and vimentin. Antibodies that can be detected in preimmune mice as weakly binding to the cytoskeleton (greater than CS) are elevated in potency after immunization with either active or UV-inactivated pure vaccinia, suggesting that virus replication may not be obligatory for activation of greater than CS lymphocyte clones. Demonstration of a cross-reactivity of one IF monoclonal antibody with virally coded hemagglutinin, expressed at the surface, raises questions about the development of pathologic conditions associated with virus-mediated autoimmunity.