The expression of the transformation-associated Epstein-Barr virus (EBV)-encoded nuclear antigens (EBNAs) 1 to 6 and membrane protein LMP-1 was studied in a series of somatic cell hybrids derived from the fusion of the EBV-transformed lymphoblastoid cell line (LCL) KR-4, and the EBV-carrying Burkitt's lymphoma lines Daudi, P3HR-1 and Raji, with non-B cell lines of fibroblast, erythroid, myeloid and epithelial origin. Expression of EBNAs 2 to 6 was down-regulated in the hybrids in parallel with extinction of the B cell markers CD19, CD20, CD21, CD23, HLA class II, and surface or cytoplasmic immunoglobulin. LMP-1 was expressed independently of EBNA-2 in hybrids derived by the fusion of the LMP-1-positive KR-4 and P3HR-1 cell lines with epithelial and myeloid cells, respectively. LMP-1 was down-regulated in hybrids derived by the fusion of P3HR-1 with an erythroid cell line and in the hybrid between Raji and a mouse fibrosarcoma line. EBNA-1 was the only EBV antigen that was regularly expressed in the hybrids regardless of the dominating cellular phenotype. The autonomous expression of EBNA-1 suggests that its regulatory pathway is independent of phenotype-associated cellular or viral factors. In contrast, the expression of EBNAs 2 to 6 appears to require a B cell environment. EBNA-2 was shown to contribute to the regulation of LMP expression in B cells. We show that in LCL-carcinoma hybrids the dominating epithelial phenotype is permissive for LMP expression in the absence of EBNA-2.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error