Role of Ia antigen in the induction of adoptively transferred acute and chronic relapsing demyelinating disease in mice.

Acute and chronic relapsing forms of experimental allergic encephalomyelitis (EAE) can be induced in SJL/J mice following transfer of myelin basic protein (MBP)-sensitized T cells which have been challenged in vitro with MBP. In this study, addition of specific anti I-A antibody during the culture blocked the antigen-specific proliferation of T cells and inhibited the transfer of both acute and relapsing EAE. Treatment of T cell recipients with anti I-As antibody daily for 10 days suppressed the induction of acute EAE. Further treatment of mice with anti I-As antibody reduced the number of relapses and improved their conditions. We conclude that MBP-sensitized T cells interact with Ia positive cells, both in vitro and in vivo, to induce acute and chronic relapsing EAE, respectively. The mechanism of this interaction and its role in the disease process are discussed.