Recombinant Polyclonal Antibody Libraries for Breast Cancer Therapy

Abstract

Abstract : This project proposes the development of a recombinant polyclonal antibody specific for the human breast carcinoma cell line BT-20. The proposed library would target multiple epitopes on the human cell line and also provide the genes necessary for the unlimited perpetuation of the defined antibody mixture. Ultimately, such antibody libraries could be used for treatment and diagnosis of breast cancer in humans. In the present study, V region genes for construction of a polyclonal Fab phage display library were obtained from the spleen, bone marrow, and intestine of a BALB/c mouse that had been immunized with BT-20 cells. The light and heavy chain V region genes were linked by reverse transcription-polymerase chain reaction (RT-PCR) and cloned into a bidirectional phagemid vector to express an Fab-displaying phage library. This library was then selected for binding to BT-20 cells. Direct and inhibition ELISA showed that the selected Fab phage display library bound specifically to BT-20 cells, and that this binding could be inhibited by BT-20 as well as by other human breast cancer cell lines, but not by sheep red blood cells. These results demonstrate that the first phase of generating a polyclonal antibody library can be done successfully.