No evidence of murine-like gammaretroviruses in CFS patients previously identified as XMRV-infected

Wisconsin Viral Research Group, Milwaukee, WI 53226, USA.
Science (Impact Factor: 31.48). 06/2011; 333(6038):94-7. DOI: 10.1126/science.1204963
Source: PubMed

ABSTRACT Members of the gammaretroviruses--such as murine leukemia viruses (MLVs), most notably XMRV [xenotropic murine leukemia virus (X-MLV)-related virus--have been reported to be present in the blood of patients with chronic fatigue syndrome (CFS). We evaluated blood samples from 61 patients with CFS from a single clinical practice, 43 of whom had previously been identified as XMRV-positive. Our analysis included polymerase chain reaction and reverse transcription polymerase chain reaction procedures for detection of viral nucleic acids and assays for detection of infectious virus and virus-specific antibodies. We found no evidence of XMRV or other MLVs in these blood samples. In addition, we found that these gammaretroviruses were strongly (X-MLV) or partially (XMRV) susceptible to inactivation by sera from CFS patients and healthy controls, which suggested that establishment of a successful MLV infection in humans would be unlikely. Consistent with previous reports, we detected MLV sequences in commercial laboratory reagents. Our results indicate that previous evidence linking XMRV and MLVs to CFS is likely attributable to laboratory contamination.

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Available from: Allyn Knox, Aug 05, 2014
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    Sensors and Actuators B Chemical 07/2014; 197:244–253. DOI:10.1016/j.snb.2014.03.011
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    • "However, gammaretroviruses are known to induce cancer in animals, understanding XMRV or related MLV infections in human prostate cancer tissues will shed light on their potential contribution to human disease. Proposed reasons to explain the conflicting data are unknown but may be: technical differences, lack of standardized XMRV PCR assays, assay sensitivity, contamination by and cross-reactivity of XMRV PCR assays with closely related endogenous MLVs such as trace quantities of mouse genomic DNA found in reagents and samples (Hue et al., 2010; Oakes et al., 2010; Robinson et al., 2010; Sato et al., 2010; Knox, Carrigan et al., 2011; Tuke et al., 2011), differences in the geographical distribution of XMRV, sequence differences among XMRV genomes (Silverman et al., 2010; Singh et al., 2010; Knox et al., 2011) and factors related to the population genetic factors (Switzer et al., 2011). Due to public health and medical consequences of potential XMRV or related MLVs infection in humans, we considered it is important to confirm or reject their association with prostate cancer in Iranian context. "
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    ABSTRACT: Background: Multiple etiologies have been hypothesized for prostate cancer, including genetic defects and infectious agents. A recently reported gamaretrovirus, xenotropic murine leukemia virus-related virus (XMRV) has been reported to be detected in prostate cancer. However, this virus has not been detected in similar groups of patients in other studies. Herein, we sought to detect XMRV in prostate cancers and benign controls in Sanandaj, west of Iran. Materials and Methods: In a case-control study, genomic DNA was extracted from formalin fixed and paraffin embedded prostate tissues from a total of 163 Iranian patients. We developed a conventional and a nested PCR assay using primers targeting to an env specific sequence of XMRV. PCR assays were carried out on 63 prostate cancers and 100 benign prostate hyperplasias. Results: Beta-actin sequences were successfully detected in the DNA extracts from all prostate tissues, confirming DNA extraction integrity. We did not detect XMRV in samples either from prostate cancers or benign prostate hyperplasias using XMRV specific primers. Conclusions: We conclude that in our population XMRV does not play a role in genesis of prostate cancer.
    Asian Pacific journal of cancer prevention: APJCP 11/2013; 14(11):6929-33. DOI:10.7314/APJCP.2013.14.11.6929
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    • "Initially, 43 of these samples had tested positive for XMRV. The results were consistent with previous reports that detected MLV nucleic acid sequences in commercial reagents and that the previous evidence linking XMRV and MLVs to CFS was likely attributable to contamination (Knox et al., 2011). "
    04/2012; , ISBN: 980-953-307-582-7
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