Isolation of a novel IgG from a patient with lung cancer using immunoassays and cloning.

Résumé fourni par la source

e22163 Background: Cancer cells express novel antigens that are characteristic of the transformed state and may engender an immune response ( i.e., antibody production) in patients. These antibodies may identify novel immune targets for antibody-based immunotherapies and diagnostics. Furthermore, the presence of these auto-antibodies could be followed as biomarkers of therapeutic response or relapse. Previous studies of the antibody response to tumors have been hampered by inefficient methods of cloning the human antibodies in their native configurations. We collected blood samples from a group of lung cancer patients with diverse clinical and pathologic features and are characterizing the anti-tumor antibody response using a variety of whole-cell binding assays. Our approach also uses an optimized hybridoma method to clone tumor-specific IgG antibodies from primary memory B-cells. Methods: We obtained serum and peripheral blood mononuclear cell samples from 50 patients with advanced lung cancer. We characterized the immune response of these patients to tumor cell lines using fluorescence microscopy with the Operetta (Perkin Elmer) and by whole-cell ELISA. We performed a cell fusion using B-cells from one of the immunoreactive patients, screening the hybridomas for antibodies specific for binding in the whole cell ELISA. We characterized the antibody activity using flow cytometry and immunoblotting, and we identified the antigen using mass spectroscopy analysis of a gel-purified, immunoreactive band. We confirmed the identity of the antigen bound by immunoblotting to recombinant protein. Results: Human IgG antibodies immunoreactive with human cancer cell lines are prevalent in our panel of lung cancer patients. Using our hybridoma method, we isolated a human IgG that binds a tumor-specific surface antigen expressed in a variety of tumors, but only minimally expressed by normal cells. Conclusions: Novel IgG antibodies against specific tumor antigens can be isolated from lung cancer patients’ serum.Using our novel hybridoma method for cloning human antibodies, we have identified an antibody that binds a tumor-specific antigen. The study of these antibodies may lead to novel biomarkers for cancer diagnosis and therapy.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.