Small Ruminant Lentiviruses (SRLVs) Break the Species Barrier to Acquire New Host Range

Viruses

Juliano Cezar Minardi da Cruz²  Dinesh Kumar Singh¹  Ali Lamara³ 

[1] Department of Life Sciences, Winston-Salem State University, Winston Salem, NC 27110, USA;Laboratory Animal Health, Embrapa Goat and Sheep Research Center, CP 145, CEP 62010-970, Sobral, Ceará, Brazil;Veterinary Superior National School of Algiers, Route de Beaulieu-El Harrach-Alger 16200, Algeria

关键词: SRLV;    cross-species;    wild ruminants;    adaptation;    genetic diversity;    recombination;    primate lentivirus;   

DOI  :  10.3390/v5071867

来源: mdpi

【 摘 要 】

Zoonotic events of simian immunodeficiency virus (SIV) from non-human primates to humans have generated the acquired immunodeficiency syndrome (AIDS), one of the most devastating infectious disease of the last century with more than 30 million people dead and about 40.3 million people currently infected worldwide. Human immunodeficiency virus (HIV-1 and HIV-2), the two major viruses that cause AIDS in humans are retroviruses of the lentivirus genus. The genus includes arthritis-encephalitis virus (CAEV) and Maedi-Visna virus (MVV), and a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs), affecting goat and sheep. Lentivirus genome integrates into the host DNA, causing persistent infection associated with a remarkable diversity during viral replication. Direct evidence of mixed infections with these two closely related SRLVs was found in both sheep and goats. The evidence of a genetic continuum with caprine and ovine field isolates demonstrates the absence of an efficient species barrier preventing cross-species transmission. In dual-infected animals, persistent infections with both CAEV and MVV have been described, and viral chimeras have been detected. This not only complicates animal trade between countries but favors the risk that highly pathogenic variants may emerge as has already been observed in the past in Iceland and, more recently, in outbreaks with virulent strains in Spain. SRLVs affecting wildlife have already been identified, demonstrating the existence of emergent viruses adapted to new hosts. Viruses adapted to wildlife ruminants may acquire novel biopathological properties which may endanger not only the new host species but also domestic ruminants and humans. SRLVs infecting sheep and goats follow a genomic evolution similar to that observed in HIV or in other lentiviruses. Lentivirus genetic diversity and host factors leading to the establishment of naturally occurring virulent versus avirulent infections, in addition to the emergence of new strains, challenge every aspect of SRLV control measures for providing efficient tools to prevent the transmission of diseases between wild ungulates and livestock.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.