Examination of lymphokines induced in mice following immunization with recombinant simian virus 40 large tumor antigen.

Baculovirus-derived recombinant simian virus 40 (SV40) large tumor antigen (T-Ag) was used to immunize BALB/c mice to examine the lymphokines produced following immunization. Specifically, we examined production of interleukin-2 (IL-2), IL-4, IL-5 and interferon gamma (IFN gamma) from immune lymphocytes cultured with decreasing concentrations of recombinant SV40 T-Ag. We identified elevated levels of IFN gamma and IL-2 by enzyme-linked immunosorbent assay and a murine CTLL-2 proliferation bioassay respectively. We were unable to detect either IL-4 or IL-5. These data indicate the previously reported tumor immunity induced by recombinant SV40 T-Ag immunization most likely reflects a TH1-like immune response based on the in vitro production of both IFN gamma and IL-2 by immune lymphocytes.