Transient expression of the Epstein-Barr virus LMP1 gene in human primary B cells induces cellular activation and DNA synthesis.
The Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) and Epstein-Barr virus nuclear antigen 2 (EBNA2) are expressed in EBV-immortalized human B cells. It has previously been shown that transfection of the LMP1 and EBNA2 genes into Burkitt's lymphoma cell lines results in the up-regulation of CD23, CD21, ICAM-1 and LFA-1 cell-surface proteins. In the present study, the effects of transient expression of the LMP1 and EBNA2 genes were studied in normal primary human B cells pretreated with UV-inactivated EBV particles. To identify and purify cells which express the transfected DNA we used a gene encoding a surface molecule, CD2, as a co-transfection marker. We show that transient expression of the LMP1 gene, from heterologous promoters, is sufficient to induce cellular enlargement and up-regulation of surface expression of the activation markers CD23, CD21, ICAM-1 and LFA-1 in primary B cells. Most importantly, we show that transient expression of the LMP1 gene is sufficient to induce DNA synthesis in human primary B cells. Transient EBNA2 expression enhanced the effect of transient LMP1 expression on CD21 and CD23 cell-surface expression but, under our experimental conditions, inhibited the induction of DNA synthesis by LMP1. We conclude that activation of primary B cells with inactivated EBV particles, followed by transient expression of only two viral genes, EBNA2 and LMP1, is sufficient to reconstitute some of the early events of B-cell immortalization by EBV.
Unit for Applied Cell and Molecular Biology, University of Umeå, Sweden.
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Peng
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Lundgren
D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000956:Antigens, Viral / Q000032:analysis / Q000235:genetics* / Q000633:toxicity; D001402:B-Lymphocytes / Q000382:microbiology*; D018801:CD2 Antigens; D004247:DNA / Q000096:biosynthesis*; D019309:Epstein-Barr Virus Nuclear Antigens; D015870:Gene Expression; D005814:Genes, Viral; D004854:Herpesvirus 4, Human / Q000235:genetics*; D006801:Humans; D008213:Lymphocyte Activation; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011971:Receptors, Immunologic / Q000032:analysis; D014158:Transcription, Genetic; D015854:Up-Regulation; D014763:Viral Matrix Proteins
D000945:Antigens, Differentiation, T-Lymphocyte; D000956:Antigens, Viral; D018801:CD2 Antigens; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D019309:Epstein-Barr Virus Nuclear Antigens; D011971:Receptors, Immunologic; D014763:Viral Matrix Proteins; D015240:Phorbol 12,13-Dibutyrate; D004247:DNA