Immunological effects of tumor vaccines: III. Influenza virus oncolysates inhibit the TPA induced activation of peripheral blood mononuclear cells.

ABSTRACT

This paper investigates the effects of tumor vaccines on T cell proliferation induced by 12-0 tetradecanoylphorbol-13-acetate (TPA). Viral oncolysate (VO) tumor vaccines containing inactivated influenza virus A significantly inhibited TPA-induced T cell proliferation. In contrast, a control tumor vaccine (CO) that contained the same cellular components as VO but lacked influenza virus did not affect the TPA-induced proliferation. These effects were also observed with peripheral blood mononuclear cells (PBMC) from ovarian cancer patients, although VO and CO each induced significant and similar levels of proliferation in these cells in the absence of TPA. Protein kinase C (PKC) is a pivotal enzyme in signal transduction pathways that control cell proliferation, and TPA is a specific activator of PKC. VO and CO showed differential effects on the inhibition of purified protein kinase C (PKC). These studies demonstrate the antagonistic effects of different tumor vaccines on T lymphocyte proliferation and suggest that influenza virus A or virus-modified cellular components may interfere with signal transduction in the immune cells of the recipient of the tumor vaccine.