Retargeting of T cells to prostate stem cell antigen expressing tumor cells: Comparison of different antibody formats - Abstract

Medical Faculty Carl Gustav Carus, Institute of Immunology, Technical University Dresden, Dresden, Germany.


Prostate cancer (PCa) is the most common malignant disease in men. Novel treatment options are needed for patients after development of metastatic, hormone-refractory disease or for those who have failed a local treatment. The prostate stem cell antigen (PSCA) is expressed in >80% of primary PCa samples and bone metastases. Its expression is increased both in androgen-dependent and independent prostate tumors, particularly in carcinomas of high stages and Gleason scores. Therefore, PSCA is an attractive target for immunotherapy of PCa by retargeting of T cells to tumor cells.

A series of different bispecific antibody formats for retargeting of T cells to tumor cells were described but, only very limited data obtained by side by side comparison of the different antibody formats are available. We established two novel bispecific antibodies in different formats. The functionality of both constructs was analyzed by FACS and chromium release assays. In parallel, the release of pro-inflammatory cytokines was determined by ELISA.

Irrespective of the underlying antibody format, both novel bispecific antibodies cause an efficient killing of PSCA-positive tumor cells by pre- and non-pre-activated T cells. Killing and release of pro-inflammatory cytokines requires an antigen specific cross-linkage of the T cells with the target cells.

Written by:
Feldmann A, Stamova S, Bippes CC, Bartsch H, Wehner R, Schmitz M, Temme A, Cartellieri M, Bachmann M.   Are you the author?

Reference: Prostate. 2011 Jun 15;71(9):998-1011.
doi: 10.1002/pros.21315

PubMed Abstract
PMID: 21541976 Prostate Cancer Section