Simian Exogenous Retroviruses
Jonathan Luke Heeney and Ernst J. Verschoor
from: Retroviruses: Molecular Biology, Genomics and Pathogenesis (Edited by: Reinhard Kurth and Norbert Bannert). Caister Academic Press, U.K. (2010)
Simians include diverse species of monkeys which are globally distributed predominantly in the southern hemisphere, and ape species that are restricted to the rainforests of central Africa and Southeast Asia. Types of simian retroviruses have been detected in almost all species of non-human primates which have been studied. As early identification and classification of primate retroviruses was largely possible due to the efforts to establish cell lines from various primate species, there were limitations. Firstly, the search for simian retroviruses was frequently restricted to only a few species cell lines. Secondly, not all retroviruses were permissive to the available cell lines due to species specific restriction or cell-type specific factors. The earliest discoveries of simian retroviruses were often based on a specific observations which arose from diagnostic workups of cases of then undefined illness or unusual cancers. This chapter focuses on the four main groups of exogenous simian retroviruses; type D simian retroviruses (SRV), simian foamy viruses (SFV) commonly known as spumaviruses, the simian T-cell lymphotropic viruses (STLV), and the expanding group of simian immunodeficiency viruses (SIV). Initially viruses in these subgroups of simian retroviruses were identified based on the diseases from which they were associated with. Retroperitoneal firbrosarcomas and chronic wasting disease led to the early identification of the SRVs, found to be associated with a spectrum of diseases in different species of macaques. Other simian retroviruses are frequently asymptomatic in their natural hosts and in some cases simply cause cytopathic effect (CPE) in cell culture (SFV). In the last two decades molecular techniques have provided us with much more insight into the phylogeny of the wide variety of diverse retroviruses, knowledge which has enriched the seroprevalence evidence of widespread retroviral infections in many different primate species read more ...