| First Author | Fassò M | Year | 2008 |
| Journal | Proc Natl Acad Sci U S A | Volume | 105 |
| Issue | 9 | Pages | 3509-14 |
| PubMed ID | 18303116 | Mgi Jnum | J:132881 |
| Mgi Id | MGI:3777079 | Doi | 10.1073/pnas.0712269105 |
| Citation | Fasso M, et al. (2008) SPAS-1 (stimulator of prostatic adenocarcinoma-specific T cells)/SH3GLB2: A prostate tumor antigen identified by CTLA-4 blockade. Proc Natl Acad Sci U S A 105(9):3509-14 |
| abstractText | Discovery of immunologically relevant antigens in prostate cancer forms the basis for developing more potent active immunotherapy. We report here a strategy using the transgenic adenocarcinoma of mouse prostate (TRAMP) model, which allows for the functional identification of immunogenic prostate tumor antigens with relevance for human immunotherapy. Using a combination of active tumor vaccination in the presence of CTL-associated antigen 4 (CTLA-4) in vivo blockade, we elicited tumor-specific T cells used to expression clone the first T cell-defined TRAMP tumor antigen, called Spas-1 (stimulator of prostatic adenocarcinoma specific T cells-1). Spas-1 expression was increased in advanced primary TRAMP tumors. We show that the immunodominant SPAS-1 epitope SNC9-H(8) arose from a point mutation in one allele of the gene in TRAMP tumor cells, and that immunization with dendritic cells pulsed with SNC9-H(8) peptide resulted in protection against TRAMP-C2 tumor challenge. In humans, the Spas-1 ortholog SH3GLB2 has been reported to be overexpressed in prostate cancer metastases. Additionally, we identified a nonmutated HLA-A2-binding epitope in the human ortholog SH3GLB2, which primed T cells from healthy HLA-A2(+) individuals in vitro. Importantly, in vitro-primed T cells also recognized naturally processed and presented SH3GLB2. Our findings demonstrate that our in vivo CTLA-4 blockade-based T cell expression cloning can identify immunogenic cancer antigens with potential relevance for human immunotherapy. |
