Generation of Therapeutic T Cells for Prostate Cancer

University dissertation from Uppsala : Acta Universitatis Upsaliensis

Abstract: The work presented herein focuses on the activation of the adaptive immune system in order to develop T cell-based immunotherapy for viral infections and cancer. The main goal was to identify and activate viral or tumoral antigen-specific T cells by using different identification, isolation and stimulation techniques. One such approach was that we modified dendritic cells (DCs) with an adenoviral vector encoding the full length pp65 antigen from cytomegalovirus (CMV). Through strategic modification techniques we demonstrate that it is possible to obtain DCs presenting antigen-specific peptides both on major histocompatibility complex (MHC) class I and MHC class II molecules for simultaneous CD8+ and CD4+ T cell activation. We also demonstrate that it is possible to generate prostate antigen-specific CD8+ T cells from a naïve repertoire of T cells by using DCs and HLA-A2-restricted peptides derived from prostate tumor-associated antigens or by using an adenoviral vector encoding the full length prostate tumor-associated antigen STEAP. We further demonstrate that CD8+ T cells directed against several prostate-specific peptide epitopes can be found in peripheral blood and in the prostate tumor area of prostate cancer patients. Furthermore, we have characterized a number of prostate-derived cell lines in terms of HLA haplotype and tumor-association antigen expression. We concluded that our methods for generating T cells restricted to CMV antigen have the ability to be applied for adoptive T cell transfer to patients with CMV disease and that prostate antigen-specific T cells can be found within prostate cancer patients, which enables future development of immunotherapeutic strategies for prostate cancer.