RESUMO
BACKGROUND: Designer T cells are T lymphocytes engineered toward specific antibody-type membrane antigens through chimeric immunoglobulin-T-cell receptor (IgTCR) genes that have been used for adoptive cellular immunotherapy. We have extended this approach to prostate specific membrane antigen (PSMA) as a means to attack prostate cancer. METHODS: A chimeric anti-PSMA IgTCR gene was constructed based on an anti-PSMA monoclonal antibody, 3D8. Both T-cell lines and primary cultured human T lymphocytes were transduced with the chimeric anti-PSMA IgTCR construct and were analyzed for IgTCR expression, specific activation by PSMA, cytotoxicity against PSMA-expressing tumor cells in vitro, and retardation of tumor growth in an animal model. RESULTS: The IgTCR was incorporated into the TCR-CD3 complex and formed a functional chimeric complex. The IgTCR-modified T cells were specifically activated through the chimeric receptor with PSMA as measured by IL-2 production and increased CD25 expression and specifically lysed the PSMA-expressing prostate cancer cells in vitro as well as retarded tumor growth in an animal model. CONCLUSIONS: The anti-PSMA designer T cells exhibit an antibody-type specificity that can recognize PSMA expressing tumor cells in a MHC-independent fashion, resulting in T-cell activation, target cell lysis in vitro and inhibition of tumor growth in vivo.
Assuntos
Antígenos de Superfície/imunologia , Glutamato Carboxipeptidase II/imunologia , Cadeias Pesadas de Imunoglobulinas/imunologia , Imunoterapia Adotiva/métodos , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/terapia , Receptores de Antígenos de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/genética , Anticorpos Monoclonais/imunologia , Linhagem Celular Tumoral , Clonagem Molecular , Testes Imunológicos de Citotoxicidade , Citometria de Fluxo , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Cadeias Leves de Imunoglobulina/imunologia , Ativação Linfocitária/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Testes de Precipitina , Receptores de Antígenos de Linfócitos T/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/imunologiaRESUMO
Identifying immunogenic tumor antigens plays a critical role in developing efficient diagnostic and therapeutic strategies for treatment of cancer. Using a recently developed technology, serological identification of antigens by recombinant expression cloning (SEREX), we identified a total of 8 genes whose expression elicited antibody responses in prostate cancer patients. Of the 8 genes, 5 represented known genes in the GenBank database, 2 were previously uncharacterized genes, and 1 showed sequence homology to a mouse gene. The sequence feature and the expression of one of the novel genes, prostate antigen recognized and identified by SEREX (PARIS-1), are determined in this study. The PARIS-1 cDNA is 3257 bp in length and contains a complete open reading frame of 2751 bp encoding for a primary translation product of 917 amino acids. Using Northern blot hybridization assay, we detected a single species of approximately 3.3 kb PARIS-1 mRNA that is differentially expressed in prostate normal and cancer cells. Western blot analysis confirmed the expression of the PARIS-1 protein in these cells. Structure analysis revealed that PARIS-1 protein contains a TBC domain that is conserved in the family of cell cycle-regulatory and Rab GTPase-activating proteins (Rab-GAP). Thus, the PARIS-1 protein may play a role in regulation of cell differentiation and growth or represent a new member of the Rab-GAP family.