EBV-SPECIFIC CYTOTOXIC T-LYMPHOCYTES FOR EBV-POSITIVE NASOPHARYNGEAL CANCER PTS

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this study we wish to generate polyclonal EBV specific cytotoxic T cells and adoptively transfer them to patients with active Nasopharyngeal Carcinoma. The lymphoblastoid cell lines, which are used to generate polyclonal CTLs, express the entire range of EBV derived gene products including LMP-1 and LMP-2. Although LMP-specific CTLs are in a minority, it is possible that even in small numbers they will have the ability to recognize and kill LMP-1 expressing cells including the NPC tumor cells. The Specific Aims of this project are: 1) To determine the feasibility of generating EBV specific cytotoxic T cell lines from patients with active Nasopharyngeal Carcinoma. 2) To determine the safety of two intravenous injections of autologous EBV specific cytotoxic T-lymphocytes (CTL) in patients with Nasopharyngeal Carcinoma. 3) To determine the survival, immunological efficacy and anti-tumor effects of EBV specific cytotoxic T-lymphocyte lines. Nasopharyngeal carcinoma, is a malignant disease with a variable range of incidence depending on age, geographical place, race and Epstein-Barr virus (EBV) exposure. It has an annual incidence of nearly 1 case per 100,000 children < 21yrs in the USA. For the majority (75-91%) of patients, the long-term prognosis is favorable with combined modality therapy. Of the 10-15% of patients who relapse after initial therapy, only 40% will enter a second remission. For the remainder who fail salvage chemotherapy or relapse for a second time, the prognosis is poor. In adults, the overall 5-year survival rates following radiotherapy are stage dependant and range from 70% to 80% for stage I, and 20-40% for stage IV. For more advanced disease, the use of combined modality therapy in adults results in an overall survival of 50%. Although overall survival rates are good in children, current treatment regimens are still far from ideal. Late medical complications after treatment for NPC include growth hormone deficiency, hypothyroidism and pulmonary fibrosis. A large restrospective study in Taiwan of a cohort of 1,549 patients was performed to assess the risk of secondary malignancies in NPC patients post radiotherapy +/- chemotherapy. The patients ranged in age from 10-80years (median 46.3years) with a maximum follow-up of 16 years. Fatal neoplastic complications included secondary leukemia related to alkylating agent chemotherapy and head and neck cancers (most likely radiation induced), and gastric cancer. It is therefore desirable to develop novel therapies that could improve disease free survival in relapsed/refractory patients and which might ultimately reduce the incidence of long term treatment related complications in all patients. The etiological factors of endemic NPC include EBV, environmental risk factors and genetic susceptibility. The etiological link between NPC and EBV was first based on serological evidence. Elevated IgG and IgA antibody titers are frequently seen. The association between EBV and NPC was subsequently confirmed by showing that EBV DNA was present in the NPC tumor cells and that EBV DNA in NPC biopsy samples is clonal, arising from a single EBV infected cell. EBV has been detected in virtually all cases of undifferentiated non-keratinizing NPC. On the other hand, squamous cell NPC appear to show a geographical variability with regard to their EBV association with higher EBV positive tumors seen in high incidence areas such as Asia. In addition, squamous cell NPC appears to represent a more heterogeneous group of tumors with other co-factors such as smoking and human papilloma virus (HPV) contributing to the pathogenic process. Nevertheless, the strong association of NPC with EBV remains. Thus NPC may represent a final common response to several pathological processes that include viral infections, occupational and environmental stimuli with, perhaps, a genetic contribution. In primary infection, the main route of entry for EBV is via the oropharyngeal epithelium. Viral replication in these cells subsequently allows infection of B lymphocytes thus resulting in a polyclonal expansion of transformed B cells. Both humoral and cell mediated immunity have important roles to play in the control of EBV. EBV-specific CD8+ CTLs are thought to be the most important defense mechanism against outgrowth of EBV-infected B cells. These cells recognize peptide fragments, derived from viral antigens, expressed on the surface of antigen presenting cells in association with MHC molecules. EBV positive NPC cells regularly express the nuclear antigen ENBA1 and a subset of tumors also appear to be latent membrane protein LMP1 positive. Transcriptional analysis has shown expression of LMP2 mRNA in the majority of tumor biopsies. In addition, transcription of the BARF0 gene has been detected in NPC cells.