Artificial Antigen Presenting Cells Expand NY-ESO-1 Antigen-Specific CD8+ T Cells From Patients with Melanoma

Abstract 4309

The NY-ESO-1 antigen is an attractive prototype cancer-testis (CT) antigen because it is expressed in a wide variety of tumors, including myeloma, melanoma, and synovial cell sarcoma, among others, but has restricted expression in normal tissues (testis and placenta). Based on our previous experience with 3T3-based artificial antigen presenting cells (AAPCs) in expanding influenza and CMV-specific T cells, we hypothesized that AAPCs expressing the NY-ESO-1 antigen and optimal costimulatory molecules would efficiently expand NY-ESO-1 specific T cells for potential use as adoptive immunotherapy. Accordingly, AAPCs were transduced to express the common MHC allele HLA-A*0201, beta2-microglobulin, and the full-length NY-ESO-1 protein, together with the T cell costimulatory ligands CD58, CD54, and CD80. These A2/NY-ESO-1 AAPCs expanded NY-ESO-1 specific T cells from normal donors after prolonged culture (4 weeks). In patients with melanoma who had detectable NY-ESO-1 antibodies, AAPC stimulation of PBMC expanded NY-ESO-1 antigen-specific CD8+ T cells approximately 3–4 logs in 3 weeks. These expanded T cells were functional in that they lysed peptide-pulsed targets (T2 cells) and native melanoma tumor targets (SK Mel 37). Expanded CD8+ T cells also produced interferon-gamma, MIP-1 beta, TNF-alpha and CD107a (but not IL-2) in response to antigen, indicating a polyfunctional response. We are currently performing scale-up experiments and pre-clinical validations of these AAPCs to embark on a clinical trial of adoptive cell therapy of NY-ESO1-specific T cells in patients with NY-ESO1-expressing tumors.