Development of a pan-retrovirus detection system for multiple sclerosis studies

Abstract

Introduction - Although recent claims implicating HTLV-1 in multiple sclerosis (MS) have been refuted, several reports suggest that another, hitherto uncharacterised, retrovirus may be involved. We have developed and applied a novel PCR-based strategy to explore this possibility. Methods - Degenerate oligonucleotides were used in a semi-nested format to amplify, from reverse-transcribed RNA, a region of the pol gene which is well conserved amongst all known retroviruses. Results - The ‘pan-retrovirus’ detection system was shown to be capable of detecting diverse retroviruses including human lentivirus, human oncovirus, simian D-type virus and murine oncovirus. The ‘pan-retrovirus’ technique identified a novel retroviral sequence, designated MSRV-cpol, in the serum of an MS patient and also in purified virions from MS patient-derived tissue cultures. Sequence comparisons suggest that in the pol gene MSRV is related (˜75% homology) to the endogenous retroviral element ERV9. Conclusion - These findings lend further support to the concept of retroviral involvement in MS.