Tumor killing effects of enterotoxins, superantigens, and related compounds

Abstract

Superantigens, including staphylococcal enterotoxins, are useful agents in the killing of tumor cells, the enhancement of antitumor immunity and in the treatment of cancer in a tumor-bearing host. In particular, the immune system of a subject with cancer is contacted with tumor cells that have been transfected with nucleic acid encoding a superantigen or biologically active polypeptide of a superantigen. Alternatively, transfected accessory cells, immunocytes or fibroblasts are used. When the superantigen is expressed in the host, T cell proliferation is induced leading to increased antitumor immunity and tumor cell killing. The nucleic acid encoding a superantigen may be administered to the tumor in vivo to transfect tumor cells wherein superantigen expression induces a similar tumoricidal immune response. Also disclosed are methods for treating a tumor wherein the transfected cells described above are incubated ex vivo with an immunocyte population, particularly T lymphocytes, to tumoricidally activate the population, followed by administering the activated population to the tumor-bearing host. Superantigens useful in these methods also include Streptococcal pyrogenic exotoxin, toxic shock syndrome toxins, mycoplasma antigens, mycobacteria antigens, minor lymphocyte stimulating antigens, heat shock proteins, stress peptides and derivatives thereof.