Detection of Epstein-Barr virus in T-cell prolymphocytic leukemia cells in vitro

Background: Epstein-Barr virus (EBV) is closely associated with the development of a number of tumors. During latent infection, EBV continuously expresses a number of viral genes which are essential for cell transformation and maintenance of the malignant phenotype of EBV-related tumors. There has been no previous link between EBV and T-cell prolymphocytic leukemia (T-PLL), a distinctive form of leukemia derived from T-cells at an intermediate stage of differentiation between a cortical thymocyte and a mature peripheral blood T-cell. Objective: To determine if EBV was present in the T-PLL cells collected. Study design: T-PLL cells were isolated from the peripheral blood of a patient diagnosed with T-PLL and continuously cultured for about 1 year. The existence of EBV in these cells was detected using multiple strategies including PCR, Western blotting, immunofluorescent assay and flow cytometry analysis. Results: The EBV genome was present in these T-PLL cells by PCR analysis across multiple sites in the viral genome. In addition, these T-PLL cells expressed a number of EBV latent antigens. The EBV oncoproteins LMP1, EBNA1 and EBNA3C were expressed in the majority of the infected cells. Conclusion: This report suggests a potential link between EBV infection and T-PLL and provides new information about the potential contribution of EBV in the initiation or maintenance of T-PLL.