XMRV appears to be derived from X-MLV and/or E-MLV. - GreenMedInfo Summary
Phylogenetic and biological analysis of a laboratory-generated gammaretrovirus xenotropic murine leukemia virus-related virus (XMRV).
Virus Genes. 2012 Oct ;45(2):218-24. Epub 2012 Jun 27. PMID: 22735937
The Institute of Human Virology and Department of Biochemistry, Key Laboratory of Tropical Disease Control of Ministry of Education, Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China.
A xenotropic murine leukemia virus-related virus (XMRV) has been reported to be an emerging pathogen associated with prostate cancer (PC) and chronic fatigue syndrome (CFS). However, recent studies have demonstrated that XMRV is a laboratory-derived virus resulting from genetic recombination between two mouse viral genomes during serial xenograft tissue transplantation. This study describes a phylogenetic analysis that compared XMRV with the ecotropic murine leukemia viruses (E-MLV), xenotropic MLV (X-MLV), and other retroviruses, including HTLV-1 and HIV-1. We found that sequences corresponding to three XMRV structural proteins (Env, Gag, and Pol) exhibited high degrees of homology with X-MLV (>91 %) and E-MLV (67-96 %), but not HTLV-1 (13-16 %) or HIV-1 (10-15 %), indicating that XMRV was derived from X-MLV and/or E-MLV. We then compared the infectivity of XMRV and E-MLV for human and murine lymphocytes, respectively. Results showed that human PBMCs were not susceptible to XMRV infection, suggesting that XMRV exhibits host cell tropism similar to E-MLV that only infects murine PBMCs. These data suggest that it is unlikely that this laboratory-generated retrovirus could cause disease in humans.