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Characterization of CD8‐positive macrophages infiltrating the central nervous system of rats with chronic autoimmune encephalomyelitis
Author(s) -
Hiraki Keiko,
Park IlKwon,
Kohyama Kuniko,
Matsumoto Yoh
Publication year - 2009
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.21924
Subject(s) - immunology , experimental autoimmune encephalomyelitis , cytotoxic t cell , cd8 , myelin oligodendrocyte glycoprotein , medicine , encephalomyelitis , multiple sclerosis , biology , immune system , in vitro , biochemistry
CD8 + macrophages appear in the central nervous system (CNS) under various pathological conditions such as trauma and ischemia. Furthermore, macrophages expressing CD8 were found in CNS lesions of chronic, but not acute, experimental autoimmune encephalomyelitis (EAE). To further characterize cells with this phenotype, we examined CD8 + macrophages/monocytes in the CNS and peripheral organs during the course of acute and chronic EAE that had been induced by immunization of rats with myelin basic protein and myelin oligodendrocyte glycoprotein, respectively. Counting CD8 + macrophages in CNS lesions revealed that their numbers increased reaching about 60% of total infiltrating macrophages in chronic EAE, while CD8 + macrophages remained less than 5% throughout the course of acute EAE. Unexpectedly, however, higher abundance of CD8 + monocytes/macrophages in the peripheral blood was found in both acute and chronic EAE. Real‐time polymerase chain reaction analysis revealed no significant difference in the levels of chemokines and chemokine receptors of blood CD8 + monocytes between acute and chronic EAE. mRNA expression of perforin, a cytotoxic substance, was up‐regulated in CD8 + monocytes compared with that of CD8 − monocytes in both acute and chronic EAE. These findings suggest that activated CD8 + macrophages may play a cytotoxic role in chronic EAE lesions and that cells other than CD8 + monocytes/macrophages determined the difference in CNS pathology between acute and chronic EAE. Analysis of CD8 + monocytes/macrophages may provide useful information to permit further dissect the pathomechanisms of multiple sclerosis and to develop effective immunotherapies against autoimmune diseases in the CNS. © 2008 Wiley‐Liss, Inc.