Function of LMP2B in EBV-positive Burkitt''s Lymphoma: Virus and cancer (German Edition)

Epstein-Barr virus (EBV) is a human γ-herpesvirusthat persists latently in the memory B-cell pool. EBVis linked to malignancies including Burkitt’slymphoma (BL) where it expresses specific latencygenes. Among these genes, latent membrane protein(LMP)2A and LMP2B seem to be involved in theregulation of EBV latency. LMP2A blocks B-cellreceptor (BCR) signalling after its engagement, whichactivates as well lytic EBV infection. Therefore,LMP2A contributes to the persistence of EBV. Bycontrast, the function of LMP2B, a splice variant ofLMP2A, is still not resolved. The experimental setuppresented in this book revealed for the first timethat silencing of LMP2B resulted in reducedexpression of lytic EBV mRNA and proteins upon BCRcross-linking. By contrast, overexpression of LMP2Bresulted in the opposite. We could furtherdemonstrate that LMP2A and LMP2B physically interactand that LMP2B resides predominantly in intracellularcompartments. In conclusion, these observationssupport the hypothesis that LMP2B exhibits a negativeregulatory effect on the ability of LMP2A to maintainlatent EBV by preventing the switch to lytic infection.