647: CD4 + CD25 + T cells prevent induction of demyelination in experimental allergic neuritis (EAN)

Abstract

Immune tolerance is induced and maintained by T cells, which express CD4 and CD25s the IlI-2 receptor alpha chain. We examine the role of these cells in Lewis rats that had recovered from EAN and were resistant to further disease induction. The CD4+CD25+ and CD4+CD25- T cell subsets were prepared form Lewis rats that had recovered from EAN and from normal Lewis rats and their function compared. First we transferred 5x106 CD4+CD25+ T cells on the day of immunization with bovine peripheral nerve myelin (n=12), these cells suppressed severity of disease to peak at a mean score of 1, compared to controls (n=10) peaking at 2.5 and those given 5×106 CD4+CD25– T cells which peaked at 3 (n=5).