Antigens recognized by IgG derived from tumor-infiltrating B lymphocytes in human lung cancer.

BACKGROUND Lung cancer tissues are often infiltrated by B lymphocytes, but it is not clear whether these infiltrations represent tumor-specific immune response or a nonspecific reaction. MATERIALS AND METHODS The serological analysis of recombinant cDNA expression libraries (SEREX) were previously modified using a severe combined immunodeficient (SCID) mice model engrafted with fresh human lung cancer. Here, a panel of antigens recognized by tumor-infiltrating B lymphocytes (TIB) in human lung cancer were characterized. RESULTS The modified SEREX analysis identified 22 distinct antigens in a large cell carcinoma of the lung. Sequence analysis and real time-PCR analysis showed that 55% of isolated antigens were overexpressed in tumor tissues and 9% had mutation. CONCLUSION The results of this study indicate that the humoral immune response of TIB in lung cancer patients can be detected in the xenotransplanted SCID mouse model and our modification shows high sensitivity and specificity for identification of tumor antigens.