Epstein-Barr virus (EBV)-induced long-term proliferation of CD4(+) lymphocytes leading to T lymphoblastoid cell lines carrying EBV

We have previously demonstrated that Epstein-Barr virus (EBV) strain B95.8 can infect and initiate a par tial transcriptional program in both CD4(+) a nd CD8(+) lymphocytes (Guan, M. X., R.-D. Zhang, B. Wu, and E. E. Henderson . 1996. J. Virol 70:7341-7346). Experiments were undertaken to determine wh ether EBV infection can alter the growth potential of T lymphocytes. Periph eral blood lymphocytes were separated into populations consisting of 99.8% CD4(+) and 98.6% CD8(+) T lymphocytes by FACS Infection of these population s with EBV resulted in blastogenesis in both CD4(+) and CD8(+) populations. Clones were established from the CD4(+) population in the presence of inte rleukin-2 Two of these clones expressed the T cell surface markers CD3 and CD4 and carried the EBV genome. One lymphoblastoid cell line (LCL) had a mi xture of CD4(+) and CD19(+) cells. The T-LCLs harboring the EBV genome in c ircular form and transcribed mRNA transcripts corresponding to BZLF1 BRLF1, BMLF1, and EBER-1 and -2. Immunofluorescence demonstrated EBNA in the nucl eus of T rosette-positive lymphoblasts with an absence of viral capsid anti gen expression. In situ hybridization for EBER showed nuclear and cytoplasm ic staining in B95.8 cells, whereas EBV-carrying T-LCLs only showed nuclear staining. These results demonstrate that EBV can both infect and induce gr owth transformation of T lymphocytes, supporting a direct role for EBV in A IDS-related EBV-associated T cell lymphomas. A better understanding of the EBV transcriptional program during EBV-induced T cell transformation could directly lead to adoptive T cell therapeutic strategies and/or more effecti ve antiviral chemotherapy for EBV-associated T cell lymphoma.