The XMRV Virus in chronic Fatigue and prostate cancer

The XMRV retrovirus has been implicated in chronic fatigue syndrome and prostate cancer . A homology search comparing retroviral with human proteins revealed short contiguous amino acid strings (typically 5-8 amino acids) matching human proteins whose dysfunction might be expected to cause fatigue, including mitochondrial proteins related to oxidative phosphorylation, glutamate receptors and their synaptic scaffolds, muscular acetylcholine receptor scaffolds and structural proteins, components of the immune system, and phosphatidylinositol signalling inter alia. Viral proteins are also homologous to members of the oestrogen, peroxisome proliferator, and CREB activated receptor networks, all of which are implicated in prostate cancer, and to a protein, SRCAP, that controls the expression of the prostate-specific antigen. These short matches are often predicted to be antigenic, and antibodies to XMRV proteins may target their human homologues. This is supported by the presence of autoantibodies to muscarinic receptors , vimentin and LAMINB1 (all XMRV homologues) in chronic fatigue syndrome sufferers. Homologous XMRV proteins might also interfere with the protein interactomes of their human homologues. Antibodies to the virus will also target their human counterparts, an autoimmune response that will be self-sustaining even if the virus has been eliminated, thus explaining the raging controversy concerning the presence or absence of XMRV in chronic fatigue sufferers.Download .pdf