The role of the immune response in TMEV infection and the development of late onset demyelination.

The nature of the role of the immune response to TMEV in the development of LODD after TMEV infection was examined by different means. Immunosuppression by both cyclophosphamide (postinfection) or adult thymectomy and ATS treatment (preinfection) did not inhibit clinical LODD. Adoptive transfer of spleen cells from infected donors with LODD facilitates LODD in the recipients compared with i.v. transfer of the freeze-thaw supernatants from such suspensions (although virus is present in splenocyte suspensions). The immune response to TMEV, both lymphoproliferative and antibody, reaches a peak coincidental with the development of LODD. The role of the immune response is equivocal depending on the stage of the viral infection, the timing of immunosuppressive treatment, and assessment.