CYTOKINE MODULATION OF IMMUNE DEFENSES IN CERVICAL-CANCER

Human papilloma viruses (HPV) are major factors in the etiology of cervical cancer. Natural killer (NK) lymphocytes, an important defense against viral diseases, are present in most HPV-associated lesions and cervical intraepithelial neoplasia. HPV positive cervical cancer cells and HPV-immortalized human cervical epithelial cells which possess properties similar to cervical dysplasia, however, are resistant to NK but are sensitive to lymphokine-activated killer (LAK) lymphocyte lysis. Sensitivity can be enhanced by treatment of cervical cells with leukoregulin, a cytokine secreted by lymphocytes. Combination treatment with leukoregulin and a chemotherapeutic drug, e.g. cisplatin, further enhances sensitivity of HPV-infected cells to LAK lymphocyte lysis. In contrast, gamma-interferon treatment of cervical cells can result in decreased sensitivity to LAK lysis illustrating the potential balance cytokines can exert in the immunologic control of cervical cancer.