Epstein-Barr virus ncRNA from a nasopharyngeal carcinoma induces an inflammatory response that promotes virus production.

Abstract

The Epstein-Barr virus M81 strain, isolated from a nasopharyngeal carcinoma, induces potent spontaneous virus production in infected B cells. We found that the M81 non-coding Epstein-Barr-encoded RNA EBER2, which carries polymorphisms that are mainly restricted to viruses found in endemic nasopharyngeal carcinomas, markedly stimulated this process. M81 EBER2 increased CXCL8 expression, and this chemokine enhanced spontaneous lytic replication levels in M81-infected B cells. Both events resulted from the endocytosis of extracellular vesicles containing EBER2 that were generated by neighbouring M81-infected B cells, thereby generating a paracrine loop. These effects were strictly dependent on a functional Toll-like receptor 7 (TLR7), a sensor of single-stranded RNA located in the endosome of these cells. These unique properties of M81 EBER2 could be ascribed to its unusually high expression level and to the ability of its single-stranded region to activate TLR7; both of these properties were dependent on M81-specific polymorphisms. Thus, M81 induced chronic inflammation in its target cells and this resulted in increased virus production. These observations provide a mechanistic molecular link between M81 virus replication-a central viral function and a cancer risk factor-and the production of a chemokine involved in inflammation and carcinogenesis.

• Authors: Zhe Li, Ming-Han Tsai, Anatoliy Shumilov, Francesco Baccianti, Sai Wah Tsao, Remy Poirey, Henri-Jacques Delecluse
• Journal: Nature microbiology (Nat Microbiol) Vol. 4 Issue 12 Pg. 2475-2486 (12 2019) ISSN: 2058-5276 [Electronic] England
• PMID: 31501540 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• CXCL8 protein, human
• Chemokines
• Epstein-Barr virus encoded RNA 2
• Interleukin-8
• RNA, Untranslated
• RNA, Viral
• TLR7 protein, human
• Toll-Like Receptor 7

Topics

• B-Lymphocytes (virology)
• Chemokines (metabolism)
• Epstein-Barr Virus Infections (immunology, virology)
• HEK293 Cells
• Herpesvirus 4, Human (genetics, growth & development)
• Host-Pathogen Interactions
• Humans
• Interleukin-8 (metabolism)
• Nasopharyngeal Carcinoma (genetics, metabolism, virology)
• Nasopharyngeal Neoplasms (genetics, metabolism, virology)
• Oncogenic Viruses
• RNA, Untranslated (genetics)
• RNA, Viral
• Toll-Like Receptor 7 (metabolism)
• Virus Cultivation
• Virus Replication