Regulation of chemokine receptor expression in human microglia and astrocytes.
It has been proposed that the positioning of mobile cells within a tissue is determined by their overall profile of chemokine receptors. This study examines the profiles of chemokine receptors expressed on resting and activated adult human microglial cells, astrocytes and a microglial cell line, CHME3. Microglia express highest levels of CXCR1, CXCR3 and CCR3. Astrocytes also have moderate levels of CXCR1 and CXCR3, and some CCR3, while both cell types also expressed CCR4, CCR5, CCR6, CXCR2, CXCR4 and CXCR5 at lower levels. Activation of the cells with the inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) and interferon-gamma (IFNgamma) increased the expression of some but not all receptors over a period of 24 h. Microglia showed moderate enhancement of receptor expression, while astrocytes responded particularly strongly to TNFalpha with enhanced CXCR3, CCR3 and CXCR1. However, the migratory and proliferative responses of the microglia and astrocytes to the same chemokine were different, with microglia migrating and astrocytes proliferating in response to CXCL10. The data indicates a mechanism by which activated microglia and astrocytes become selectively more sensitive to inflammatory chemokines during CNS disease, and the paper discusses which of the many chemokines present in CNS would have priority of action on microglia and astrocytes.
Flynn
Geraldine
G
Department of Biological Sciences, The Open University, Milton Keynes MK7 6AA, UK.
Maru
Seema
S
Loughlin
Jane
J
Romero
Ignacio A
IA
Male
David
D
D001253:Astrocytes / Q000276:immunology* / Q000378:metabolism; D001921:Brain / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D001927:Brain Diseases / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D002455:Cell Division / Q000187:drug effects / Q000276:immunology*; D002478:Cells, Cultured; D054357:Chemokine CXCL10; D019743:Chemokines, CXC / Q000494:pharmacology; D002633:Chemotaxis / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology; D017628:Microglia / Q000276:immunology* / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism; D019707:Receptors, Chemokine / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects / Q000276:immunology
D054357:Chemokine CXCL10; D019743:Chemokines, CXC; D012333:RNA, Messenger; D019707:Receptors, Chemokine; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma