Immune Evasion Strategies of Ranaviruses and Innate Immune Responses to These Emerging Pathogens

Viruses

Leon Grayfer¹  Francisco De Jesús Andino¹  Guangchun Chen¹  Gregory V. Chinchar² 

[1] Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY 14642, USA;Department of Microbiology, University of Mississippi Medical Center, Jackson, MS 39216, USA;

关键词: Iridovirus;    ranavirus;    FV3;    frog virus 3;    innate immunity;    macrophage;    anti-viral;    immune-evasion;    cytokines;    inflammation;   

DOI  :  10.3390/v4071075

来源: mdpi

【 摘 要 】

Ranaviruses (RV, Iridoviridae) are large double-stranded DNA viruses that infect fish, amphibians and reptiles. For ecological and commercial reasons, considerable attention has been drawn to the increasing prevalence of ranaviral infections of wild populations and in aquacultural settings. Importantly, RVs appear to be capable of crossing species barriers of numerous poikilotherms, suggesting that these pathogens possess a broad host range and potent immune evasion mechanisms. Indeed, while some of the 95–100 predicted ranavirus genes encode putative evasion proteins (e.g., vIFα, vCARD), roughly two-thirds of them do not share significant sequence identity with known viral or eukaryotic genes. Accordingly, the investigation of ranaviral virulence and immune evasion strategies is promising for elucidating potential antiviral targets. In this regard, recombination-based technologies are being employed to knock out gene candidates in the best-characterized RV member, Frog Virus (FV3). Concurrently, by using animal infection models with extensively characterized immune systems, such as the African clawed frog, Xenopus laevis, it is becoming evident that components of innate immunity are at the forefront of virus-host interactions. For example, cells of the macrophage lineage represent important combatants of RV infections while themselves serving as targets for viral infection, maintenance and possibly dissemination. This review focuses on the recent advances in the understanding of the RV immune evasion strategies with emphasis on the roles of the innate immune system in ranaviral infections.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.