MYELIN BASIC-PROTEIN SPECIFIC T-HELPER CELLS INDUCE EXPERIMENTAL ANTERIOR UVEITIS

Immunopathological changes in the eyes were examined in Lewis rats aft er active and passive induction of experimental autoimmune encephalomy elitis (EAE) with myelin basic proteins (MBP) at various stages of EAE , The onset of anterior uveitis (AU) coincided with hind limb paralysi s, but uveitis persisted after clinical signs of EAE had subsided, A m ild form of uveitis was characteristic for the majority of rats, The c hanges within the iris and ciliary body consisted of an accumulation o f inflammatory cells lining the anterior surface of iris, the trabecul ar meshwork, and, in some cases, within the ciliary body and the aqueo us humor. A similar histopathological picture was observed when rats w ere injected with the secondary encephalitogenic determinant for Lewis rats, MBP peptide 87-99, Flow cytometry analysis of T cells from the anterior segment of the inflamed eyes after immunization with MBP reve aled the presence of CD4(+) cells exclusively expressing V beta 8.2 an d OX-40 markers. Our data suggest that MBP are encephalitogenic and uv eitogenic in Lewis rats and that the V beta 8.2-positive T cells in th e eye represent encephalitogenic T cells. Many of those T cells were d istributed in the iris and the anterior chamber, These findings indica te that these MBP-specific T cells may play a critical role in EAE as well as in AU. (C) 1996 Wiley-Liss, Inc.