IN-VIVO GROWTH OF EPSTEIN-BARR-VIRUS TRANSFORMED B-CELLS WITH MUTATIONS IN LATENT-MEMBRANE-PROTEIN-2 (LMP2)

Epstein-Barr virus (EBV) causes infectious mononucleosis in adolescent s and is associated with malignant B lymphocyte proliferation in AIDS patients, patients undergoing immune suppression for organ transplanta tion, and SCID mice. In vitro, EBV transformed, latently infected lymp hoblastoid B cell lines (LCLs) contain EBV episomes and express nine v irus encoded proteins. Six are nuclear proteins (EBNAs) and three are the integral membrane proteins, LMP1, LMP2A, and LMP2B. To determine i f LMP2 was essential for in vivo growth, SCID mice were injected with LCLs containing wild-type EBV (LMP2(+)) or with LCLs transformed with EBV containing mutations in either LMP2A or LMP2B (LMP2(-)). SCID mice injected with the LMP2(+) or LMP2(-) LCLs were monitored for tumor de velopment, length of time to tumor development, and phenotypic charact erization of the resulting tumors. No difference was observed in any o f the above parameters between LMP2(+) and LMP2(-) LCLs demonstrating that LMP2 is not essential for the in vivo growth of EBV transformed B lymphocytes in SCID mice.