Conditional expression of a dominant-negative form of Epstein-Barr virus (EBV) nuclear antigen EBNALP inhibits EBV-positive lymphoblastoid cell growth

• Published in: Archives of Virology Vol. 165; no. 2; pp. 313 - 320
• Main Authors: Harada, Shizuko, Saijo, Masayuki
• Format: Journal Article
• Language: English
• Published: Vienna Springer Science and Business Media LLC 01.02.2020; Springer Vienna; Springer Nature B.V
• Subjects: Antigens; B-Lymphocytes; B-Lymphocytes - virology; Biomedical and Life Sciences; Biomedicine; Cell growth; Cell Line; Cell Proliferation; Cell Transformation, Viral; drug therapy; Epstein-Barr virus; Epstein-Barr Virus Nuclear Antigens; Epstein-Barr Virus Nuclear Antigens - genetics; Epstein-Barr Virus Nuclear Antigens - metabolism; Gene Expression; Herpesvirus 4, Human; Herpesvirus 4, Human - growth & development; Human gammaherpesvirus 4; Humans; Infectious Diseases; Lymphoblastoid cell lines; Lymphocytes B; Medical Microbiology; Mutant Proteins; Mutant Proteins - genetics; Mutant Proteins - metabolism; Mutants; Original Article; Protein sorting signals; transactivators; Transcription activation; transcriptional activation; viability; Viral Proteins; Viral Proteins - genetics; Viral Proteins - metabolism; Virology
• ISSN: 0304-8608; 1432-8798; 1432-8798
• DOI: 10.1007/s00705-019-04489-2

Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that transforms primary B lymphocytes, yielding lymphoblastoid cell lines (LCLs). EBV-encoded nuclear antigen 2 (EBNA2) and EBV-encoded nuclear antigen leader protein (EBNALP) are the first viral products expressed after EBV infection of primary B lymphocytes and are essential for EBV-induced B-lymphocyte growth transformation. EBNA2 functions as a transcriptional activator of viral and cellular genes, with EBNALP as a coactivator for EBNA2-mediated transcriptional activation. We previously reported that mutant EBNALP with a C-terminal 10-amino-acid truncation loses the ability to coactivate, and has a dominant-negative effect on wild-type-EBNALP-mediated coactivation. However, the functional relevance of EBNALP in maintenance of LCL cell growth has not been investigated. To address this, we have constructed LCL-derived cell clones in which this dominant-negative form of EBNALP (DNLP) is conditionally expressed by the Cre-loxP system. We used these cells to evaluate the effect of DNLP expression on EBV-induced cell proliferation. After drug treatment, the DNLP-expressing LCL clones showed reduced cell proliferation and viability. These results indicate that EBNALP is critical for maintaining LCL growth and EBV-induced cell proliferation.