Adoptive transfer of allogeneic Epstein-Barr virus (EBV)-specific cytotoxic T cells with in vitro antitumor activity boosts LMP2-specific immune response in a patient with EBV-related nasopharyngeal carcinoma

Background: The outcome of patients with nasopharyngeal carcinoma (NPC presenting as advanced-stage disease or failing conventional radio-chemotherapy is poor. Thus, additional forms of effective, low-toxicity treatment are warranted to improve NPC prognosis. Since NPC is almost universally associated with Epstein-Barr virus (EBV), cellular immunotherapy with EBV-specific cytotoxic T lymphocytes (CTLs) may prove a successful treatment strategy. Patient and methods: A patient with relapsed NPC, refractory to conventional treatments, received salvage adoptive immunotherapy with EBV-specific CTLs reactivated ex vivo from a human leukocyte antigen-identical sibling. EBV-specific immunity, as well as T-cell repertoire in the tumor, before and after immunotherapy, was evaluated. Results: CTL transfer was well tolerated, and a temporary stabilization of disease was obtained. Moreover, notwithstanding the short in-vivo duration of allogeneic CTLs, immunotherapy induced a marked increase of endogenous tumor-infiltrating CD8+ T lymphocytes, and a long-term increase of latent membrane protein 2-specific immunity. Conclusions: Preliminary data obtained in this patient indicate that EBV-specific CTLs are safe, may exert specific killing of NPC tumor cells in vitro, and induce antitumor effect in vivo.