Transcriptome profiling of a spontaneous EBV-positive B cell line

Recent studies highlight herpesvirus-associated risks in T cell therapies, such as chimeric antigen receptor (CAR) T cell and tumor-infiltrating T lymphocyte (TIL) treatments. Latent human herpesvirus 6 (HHV-6) reactivation has been observed in CAR-T cells in vivo, and there is a case report of Epstein-Barr virus (EBV)-positive B cell lymphoma following TIL therapy for metastatic melanoma. Tumor fragments used to obtain cell products for TIL therapy contain diverse cell populations, including TILs and B lymphocytes (B-TILs). During ex vivo TIL expansion for cell therapy, there is a risk that EBV-transformed B-TILs may proliferate concurrently, particularly in colorectal cancer, where EBV-positive lymphocyte infiltration of the tumor occurs in approximately 40 percent of cases. In this study, we used RNA-seq to explore the characteristics of a wild-type EBV-transformed B cell line, lcl_burn0214, and a rectal cancer tumor tissue specimen, tum_burn0214, from which it spontaneously arose during ex vivo primary culture.