Broadening Specificity and Enhancing Cytotoxicity of Adoptive T Cells for Nasopharyngeal Carcinoma Immunotherapy

Abstract

Although promising, clinical responses to adoptive immunotherapy for nasopharyngeal carcinoma (NPC) are still limited by the restricted number of Epstein-Barr virus (EBV) antigens that can be targeted and their poor immunogenicity. Our previous work indicated that the immunogenic features of the NPCassociated viral antigen BARF1 may be exploited for immunotherapeutic purposes. Nevertheless, T-cell lines obtained with current protocols include only negligible numbers of BARF1-specific cytotoxic T lymphocytes, pointing to the need to enrich these effectors in BARF1 specificities. Considering that in B lymphocytes BARF1 is mainly a lytic EBV antigen, we tested different EBV lytic-cycle inducers (TPA/butyric acid, doxorubicin, and cisplatin) used at suboptimal concentrations for their ability to upregulate BARF1 expression in lymphoblastoid B-cell lines (LCL), the commonly used antigen-presenting cells, without compromising their survival. The LCLs treated with doxorubicin (DX-LCL) can reproducibly and efficiently generate EBV-specific effectors enriched in BARF1 specificities from both healthy donors and NPC patients. These DX-LCLs also had more pronounced immunogenic properties, including HLA class I upregulation and expression of immunogenic cell death markers, such as enhanced calreticulin exposure and HMGB1 release. In particular, doxorubicin triggers an HMGB1 autocrine/ paracrine loop with its receptor, TLR4, which is also upregulated in DX-LCLs and is responsible for NF-kB activation and a delayed apoptosis that allows a prolonged stimulation of EBV-specific T-cell precursors. This protocol may thus constitute a valid alternative to the use of engineered LCLs to generate EBV-specific T-cell lines for adoptive immunotherapy, being relatively simple, easily upgradable to Good Manufacturing Practice standards, and therefore more broadly applicable.

Role of Human Leukocyte Antigen System as A Predictive Biomarker for Checkpoint-Based Immunotherapy in Cancer Patients

“…Lastly, several chemotherapeutic agents can promote the expression of HLA class I derived peptide complex. In many types of cancer cell lines cisplatin alone or in combination with vinorelbine or 5-fluorouracil [ 249 ], doxorubicin [ 250 ], the microtubule-destabilizers epothilone B, taxol and vinblastine [ 251 ] increase the expression of HLA class I APM components. Moreover, some other chemotherapeutic agents, such as the topoisomerase-I inhibitors topotecan and etoposide, indirectly induce the up-regulation of HLA class I derived peptide complex by stimulating IFN-β autocrine/paracrine signaling of tumor cells [ 252 ].…”

Immunogenic Apoptosis as a Novel Tool for Anticancer Vaccine Development

“…Particularly, TLR4 and its adaptor, myeloid differentiation primary response gene 88 (MyD88), were found to be essential for optimal antigen processing by inhibiting the fusion between phagosomes and lysosomes, thereby preventing the degradation of tumor antigens [ 78 , 79 ]. Both TLR4, expressed on APC, and HMGB1 are required for ICD and for efficient immune stimulation as demonstrated in experiments neutralizing HMGB1 [ 80 ] and in breast cancer patients having a loss-of-function TLR4 allele exhibiting reduced binding affinity for HMGB1. These patients respond poorly to radiotherapy and anthracycline therapy [ 49 , 64 ].…”

Fighting Viral Infections and Virus-Driven Tumors with Cytotoxic CD4+ T Cells

“…Therefore, T cells specific for lytic phase antigens can limit the viral spreading and the de novo infection in healthy host and EBV-seronegative recipients of transplants from EBV-seropositive donors. In an adoptive immunotherapy setting, their efficacy can be increased with the concomitant use of lytic cycle inducers, like epigenetic and chemotherapeutic agents ( 158 ).…”