Introduction - Although recent claims implicating HTLV-1 in multiple s
clerosis (MS) have been refuted, several reports suggest that another,
hitherto uncharacterised, retrovirus may be involved. We have develop
ed and applied a novel PCR-based strategy to explore this possibility.
Methods - Degenerate oligonucleotides were used in a semi-nested form
at 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, sim
ian D-type virus and murine oncovirus. The 'pan-retrovirus' technique
identified a novel retroviral sequence, designated MSRV-cpol, in the s
erum of an MS patient and also in purified virions from MS patient-der
ived tissue cultures. Sequence comparisons suggest that in the pol gen
e MSRV is related (similar to 75% homology) to the endogenous retrovir
al element ERV9. Conclusion - These findings lend further support to t
he concept of retroviral involvement in MS.