Suppressor T-lymphocytes in the spinal cord of Lewis rats recovered from acute experimental allergic encephalomyelitis.

The quantity and distribution of T-lymphocyte phenotypes in the spinal cord of Lewis rats which have recovered from acute encephalomyelitis (EAE) were studied. Lymphoid cells were detected in the spinal cords of all the recovered, asymptomatic rats for periods up to 4 months after recovery. The major difference between the T-lymphocyte populations found in acute EAE compared to the asymptomatic chronic condition was the increase of OX-8 (suppressor) T cells. Thus, the cellular infiltration of the CNS in EAE in the rat appears to be persistent after clinical recovery. Furthermore, the association between OX-8 cells in the spinal cord and the symptom-free stage of the disorder suggests that these suppressor cells exert an effect at the level of the target organ.