Evidence for two T-helper populations with distinct specificity in the humoral response to influenza A viruses.

Virus specificity of T-helper cells for the humoral antibody response to influenza A viruses was studied with a hapten-carrier secondary adoptive transfer system, using whole virus, or viral components inserted into liposomes as carrier with B cells primed to DNP human gamma globulin. Evidence was obtained for two distinct T-helper cell populations from mice primed by influenza infection: a T-helper cell cross-reactive for all type A influenza viruses and a second T-helper population specific for the variant haemagglutinin. In vivo the virus cross-reactive T helpers recognized whole virus, but did not recognize isolated surface glycoproteins or internal virus proteins.