Immunology cross-reactivity between spinal cord protein and myelin basic protein.

MyelinMyelinbasic protein-induced experimental allergic encephalitis is prevented or suppressed by pretreating guinea pigs with spinal cord protein. Although myelin basic protein and spinal cord protein do not cross-react at the antibody level, significant cross-stimulation was demonstrated in an antigen-induced lymphocyte proliferation assay. The antigen-sensitive cells were characterized as T lymphocytes in that they were immunoglobulin-negative (Ig-ve) and responded to concanavalin A. However, the level of proliferation observed in the Ig-ve population was much greater than that of undepleted cells. This suggested that there existed an immunoblobulin-bearing suppressor cell population. It was unclear whether T or B lymphocytes were responsible for this suppression in that the Ig+ve cells also responded, to some extent, to concanavalin A, indicating the presence of T cells. Nonetheless, these results suggest that a possible mechanism whereby spinal cord protein protects animals against experimental allergic encephalitis is through the induction of a population of suppressor cells which are sensitized to cross-reactive determinants.