Dynamics of Ia-expressing cells and T lymphocytes of different subsets during experimental allergic neuritis in Lewis rats.

Inflammatory cells were characterized by immunohistochemistry, utilizing monoclonal antibodies against cell surface antigens in frozen sections of sciatic nerves and nerve roots of Lewis rats, sacrificed during the course of experimental allergic neuritis. Large numbers of Ia-expressing irregular macrophage-like/dendritic cells, as well as W 3/13 reactive T lymphocytes of both W 3/25 reactive helper and ox8 reactive suppressor/cytotoxic phenotypes were seen within afflicted peripheral nervous tissue at the start of clinical symptoms and at the height of the disease. T lymphocytes of both helper and suppressor/cytotoxic phenotypes decreased concomitant with clinical recovery. During this period demyelination was still extensive and Ia-expressing macrophage-like/dendritic cells were abundant.