Expression of the beta-chemokine receptors CCR2, CCR3 and CCR5 in multiplesclerosis central nervous system tissue

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the cen tral nervous system (CNS) characterised by perivascular inflammatory cell i nfiltrates and plaques of demyelination. Chemokines have been shown to play an important role in the activation and directional migration of cells to sites of CNS inflammation. The action of chemokines requires the expression of their complementary chemokine receptors by their target cells. We have examined the expression of the beta-chemokine receptors CCR2, CCR3 and CCR5 in post-mortem MS CNS tissue using single- and double-labelling immunocyto chemistry techniques. Low levels of CCR2. CCR3 and CCR5 were expressed by m icroglial cells throughout control CNS tissue. In chronic active MS lesions CCR2, CCR3 and CCR5 were associated with foamy macrophages and activated m icroglia. CCR2 and CCR5 were also present on large numbers of infiltrating lymphocytes. A smaller number of CCR3-positive lymphocytes were present, bu t we also noted CCR3 and CCR5 on astrocytes in five of the 14 cases of MS i nvestigated, particularly associated with processes around vessels and at t he glia limitans. Ligands fur CCR3 and CCR3 include MCP-1 and MCP-3 which w ere co-localised around vessels with the infiltrating leukocytes. but were also present in unaffected areas of cortex. The elevated expression of CCR2 , CCR3 and CCR5 in the CNS in MS suggests these beta-chemokine receptors an d their ligands play a role in the pathogenesis of MS. (C) 2000 Elsevier Sc ience B.V. All rights reserved.