Cell cultures and associated retroviruses in multiple sclerosis

Abstract

Retroviral particles associated with reverse transcriptase (RT) activity in cell‐cultures from MS patients have been reported by different groups. Cell‐cultures have been used for the study and characterization of the corresponding retroviral genome which we have shown is related to ERV9 in the pol region. Previously unpublished details of a study with monocyte cultures are presented together with observations on leptomeningeal and choroid‐plexus cultures. The generation of self‐transformed cultures after inhibition of interferon, followed by the loss of retroviral expression and recurrent apoptosis, is analyzed. Retroviral particles with RT‐activity are produced in monocyte cultures with an apparent correlation with MS disease activity. However, though leptomeningeal and choroid plexus cells from MS can be passaged for a limited period, their evolution in vitro is not compatible with stable retroviral expression. These culture limitations greatly hampered progress on the elucidation of the retroviral genome sequence.