Characterization of Epstein-Barr virus-infected mantle cell lymphoma lines

It has been reported that Epstein-Barr virus (EBV) resides in resting B cel ls in vivo. However, an ideal in vitro system for studying EBV latent infec tion in vivo has not yet been established. In this study, a mantle cell lym phoma line, SP53, was successfully infected with a recombinant EBV containi ng a neomycin-resistant gene. The EBV-carrying SP53 cells were obtained by selection using G418. They expressed EBER-1, EBNAs, and LMP1; this expressi on pattern of the EBV genes was similar to that in a lymphoblastoid cell li ne (LCL). However, proliferation assay showed that the EBV-carrying SP53 ce lls have a doubling time of 73 h, compared with 57 h of SP53 cells. Transpl antation of 10(8) SP53 cells to nude mice formed tumors in 4 of 10 mice ino culated, but the EBV-carring SP53 cells did not. Unexpectedly, EBV infectio n reduced the proliferation and tumorigenicity of SP53 cells. However, the EBV-carrying SP53 cells showed higher resistance to apoptosis induced by se rum starvation than did the SP53 cells. The inhibition of proliferation and the resistance to apoptosis induced in SP53 cells by EBV infection indicat e that this cell line might to some extent provide a model of in vivo EBV r eservoir cells.