Dynamic regulation of α- and β-chemokine expression in the central nervous system during mouse hepatitis virus-induced demyelinating disease

Infection of C57BL/6 mice with the V5A13.1 strain of mouse hepatitis virus (MHV-V5A13.1) results in an acute encephalomyelitis and chronic demyelinating disease with features similar to the human demyelinating disease multiple sclerosis, Chemokines are a family of proinflammatory cytokines associated with inflammatory pathology in various diseases, The kinetics and histologic localization of chemokine production in the central nervous system of MHV-infected mite were examined to identify chemokines that contribute to inflammation and demyelination, Transcripts for the chemokines cytokine-response gene-2 (CRG-2), regulated on activation, normal T cell expressed and secreted (RANTES), macrophage-chemoattractant protein-1 and protein-3 (MCP-1, MCP-3), macrophage-inflammatory protein-1 beta (MIP-1 beta), and MIP-2 were detected in the brains of MHV-infected mice at 3 days postinfection (p.i.), and these transcripts were increased markedly in brains and spinal cords at day 7 p.i., which coincides with the occurrence of acute viral encephalomyelitis, By day 35 p.i., RANTES, CRG-2, and MIP-1 beta were detected in brains and spinal cords of mice with chronic demyelination. CRG-2 mRNA expression colocalized with viral RNA and was associated with demyelinating lesions, Astrocytes were the predominant cell type expressing CRG-2 mRNA, These observations suggest a role for chemokines, notably CRG-2, in the initiation and maintenance of an inflammatory response following infection with MHV, which is important in contributing to demyelination.