REPEATED TREATMENT WITH S. AUREUS SUPERANTIGENS EXPANDS THE SURVIVAL RATE OF EHRLICH ASCITES TUMOR BEARING MICE

Abstract

The bacterial superantigen Staphylococcal enterotoxin-A (SEA), produced by some strains of Staphylococcus aureus, causes proliferation of cytotoxic T-lymphocytes and cytokine production in vivo. SEA has been shown to be highly efficient for antibody-targeted superantegen immunotherapy for different tumor models. A candidate B-cell superantigen that has received considerable attention these days is staphylococcal protein-A (PA). It has been shown to possess multiple immunological responses. The anti-tumor property of PA is well documented in the literature in various transplantable tumors of rats and mice. In the present study, we have shown that the T-cell superantigen SEA and B-cell superantigen PA induce immunomodulatory and anti-tumor activity which is strongly protentiated by PA+SEA co-administration. Combination treatment with PA and SEA prolongs the immune response in vivo, limits the development of immunological unresponsiveness and promotes maximum anti-tumor effects to tumor carrying animals, as compared with PA or SEA alone. The immune response after combined therapy is characterized by substantially augmented IFN-γ, TNF-α, Nitric oxide and strong CTL activity. Our data demonstrate that combined PA+SEA therapy induces long-term survival of the animals, carrying the Ehrlich ascites tumor.

• Ehrlich ascites tumor
• Staphylococcal enterotoxin-A
• Protein A
• Peripheral Blood Mononuclear Cells
• Natural Killer Cells
• Combination treatment