COLOCALIZATION OF SECRETONEURIN IMMUNOREACTIVITY AND MACROPHAGE INFILTRATION IN THE LESIONS OF EXPERIMENTAL AUTOIMMUNE ENCEPHALOMYELITIS

Secretoneurin, a novel neuropeptide, has recently been shown to attrac t monocytes. In our present study we have tested whether the local pre sence of secretoneurin within the CNS of the rat may influence the top ographical distribution of inflammatory infiltrates in acute T-cell me diated encephalomyelitis. Experimental allergic encephalomyelitis was induced by passive transfer of myelin basic protein-reactive T-lymphoc ytes and the distribution of T-cells and macrophages was studied at da y 3, 4 and 7 after transfer. In the same sections secretoneurin immuno reactivity was visualized by immunohistochemistry. A clustering of mac rophages, but not of T-lymphocytes, was seen at sites of secretoneurin immunoreactivity in all stages of experimental autoimmune encephalomy elitis. Our data indicate for the first time that local neuropeptides may play a role in leucocyte recruitment into inflammatory lesions of the CNS.