Cellular immune response in multiple sclerosis plaques.
Multiple sclerosis plaques were immunohistochemically stained to exhibit cells expressing immune-system antigens. Human leukocyte antigen (HLA)-DR-positive cells formed dense rings around all plaque regions. The majority were reactive microglia/macrophages. Counterstaining with oil red O revealed heavy myelin debris within these cells. They were distinct from astrocytes, which were identified with an antibody to glial fibrillary acidic protein (GFAP) and which did not contain oil red O myelin debris. Numerous leukocytes and microglia were stained with antibody to leukocyte common antigen (LCA). Lymphocytes in cuffs around vessels, along the margins of capillary walls, and, sparingly, in the tissue matrix of affected areas, were stained with antibodies to CD4 (T-helper/inducer) and CD8 (T-cytotoxic/suppressor). In experimental allergic encephalomyelitis (EAE) induced in Lewis rats, a similar proliferation of Ia-positive (OX6, OX17) cells displaying reactive microglia/macrophage morphology was observed. These Ia-positive cells also were easily distinguished from GFAP-positive astrocytes. The results suggest that macrophages/reactive microglia, and not astrocytes, express class II MHC antigens in multiple sclerosis and EAE plaques.
Kinsmen Laboratory of Neurological Research, Department of Psychiatry, University of British Columbia, Vancouver.
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Boyle
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McGeer
D000818:Animals; D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis / Q000276:immunology; D001402:B-Lymphocytes / Q000473:pathology; D015704:CD4 Antigens / Q000032:analysis / Q000276:immunology; D016827:CD8 Antigens; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis / Q000276:immunology; D006684:HLA-DR Antigens / Q000032:analysis / Q000276:immunology; D007111:Immunity, Cellular; D007124:Immunoenzyme Techniques; D009103:Multiple Sclerosis / Q000276:immunology* / Q000473:pathology; D051381:Rats; D011917:Rats, Inbred Lew; D013194:Staining and Labeling; D013601:T-Lymphocytes / Q000473:pathology
D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D015704:CD4 Antigens; D016827:CD8 Antigens; D005904:Glial Fibrillary Acidic Protein; D006684:HLA-DR Antigens