Recognition of Fresh Human Tumor by Human Peripheral Blood Lymphocytes Transduced with a Bicistronic Retroviral Vector Encoding a Murine Anti-p53 TCR

Abstract

The p53 protein is markedly up-regulated in a high proportion of human malignancies. Using an HLA-A2 transgenic mouse model, it was possible to isolate high-avidity murine CTLs that recognize class I-restricted human p53 epitopes. We isolated the α- and β-chain of a TCR from a highly avid murine CTL clone that recognized the human p53264–272 epitope. These genes were cloned into a retroviral vector that mediated high efficiency gene transfer into primary human lymphocytes. Efficiencies of >90% for gene transfer into lymphocytes were obtained without selection for transduced cells. The p53 TCR-transduced lymphocytes were able to specifically recognize with high-avidity, peptide-pulsed APCs as well as HLA-A2.1+ cells transfected with either wild-type or mutant p53 protein. p53 TCR-transduced cells demonstrated recognition and killing of a broad spectrum of human tumor cell lines as well as recognition of fresh human tumor cells. Interestingly, both CD8+ and CD4+ subsets were capable of recognizing and killing target cells, stressing the potential application of such a CD8-independent TCR molecule that can mediate both helper and cytotoxic responses. These results suggest that lymphocytes genetically engineered to express anti-p53 TCR may be of value for the adoptive immunotherapy of patients with a variety of common malignancies.

A T cell receptor associated with naturally occurring human tumor immunity

“…The use of CTL by vaccination or adoptive T cell transfer protocols is a major current strategy for treating cancer patients (1)(2)(3)26). These include the use of TCRs specific to human-derived MART-1 (27,28), NY-ESO-1 (29), and gp-100 (30) and the murine-derived MDM2 (31) and p53 (32,33). Although these antigens are not generally believed to be associated with naturally occurring robust immune responses and spontaneous tumor regressions, evaluation of their clinical utility is ongoing.…”

Cancer Regression in Patients After Transfer of Genetically Engineered Lymphocytes

“…1A) and were able to recognize HLA-A2-matched tumors, including melanoma, lung cancer, and breast cancer (table S1). Furthermore, transduction with these TCR-encoding retro-viral vectors converted normal PBLs into cells capable of specifically recognizing and destroying both fresh and cultured cells from multiple common cancers (such as sarcoma and breast, lung, esophagus, and liver cancers) in vitro (9)(10)(11)(12).…”

“…The genes encoding the TCR that are specific for a variety of TAA have now been cloned, including the TCR-recognizing MART-1 and gp100 melanoma/melanocyte differentiation antigens, the NY-ESO-1 cancer-testis antigen that is present on many common epithelial cancers, and an epitope from the p53 molecule, which is expressed on the surface of approximately 50% of cancers of common epithelial origin (7)(8)(9)(10)(11)(12). In each case, these antigens were detected by the TCR when they were presented as peptides by molecules encoded by the major histocompatibility complex protein human lymphocyte antigen (HLA)-A2.…”

Redirecting T lymphocyte specificity by T cell receptor gene transfer – A new era for immunotherapy

“…These can be of high-affinity, if the peptide used is not homologous to any murine protein. Such an xeno-specific immunization has been shown to be feasible using peptides from the human MDM2 (Stanislawski et al, 2001) and p53 (Cohen et al, 2005;Kuball et al, 2005) genes. Finally, in vitro mutagenesis can be applied to generate TCRs of different affinities including ''unnatural'' affinities in the range of antibodies (Holler et al, 2000;Holler and Kranz, 2003).…”

“…CD4 + T cells redirected with such TCRs show similar function in comparison to patient derived CD8-independent TCRs. The redirected human CD4 + cells secrete cytokines, lyse tumor cells, proliferate, and activate APCs (Cohen et al, 2005;Kuball et al, 2005). If transgenic mice expressing chimeric molecules of HLA-A2.1 and the murine H-2D b a3 domain are used for immunizations, or if HLA-A2.1-transgenic mice additionally bear the human CD8 transgene, most TCRs obtained will be of lower affinity and remain CD8-dependent.…”