Enhancing effect of passive immunization with mycobacterial antibodies on humoral and cellular immunity in BCG-infected mice.

The present paper is an attempt to get insight about the mechanisms involved in the enhancing phenomenon that occurs in bacterial infections. Mice infected with small doses of the BCG strain of M. bovis and treated with a M. tuberculosis H37Rv antiserum investigated at various intervals for their capacity to synthesize haemagglutinating antimyco-bacterial antibodies and to develop delayed hypersensitivity to PPD. As controls, BCG-infected mice were treated with the antiserum freed from its mycobacterial antibodies. It was found that the passive immunization of BCG-infected mice promotes the growth of bacilli in their spleen and induces a late formation of antimycobacterial antibodies which do not seem to be related to the development of delayed hypersensitivity.