Identification and IFN gamma-regulation of differentially expressed mRNAs in murine microglial and CNS-associated macrophage subpopulations

CNS-resident macrophages (microglia and CNS-associated macrophages) are the main immunocompetent cells of the central nervous system (CNS) and respond by rapid activation to brain injury. Molecular events occurring during IFN gamma -activation and identification of potential markers of the CNS-resid ent macrophage subsets were investigated using microglial-derived clones (E OC) differing in their morphology and their antigen presenting activities f or CD4(+) and CD8(+) T-cells. By applying the subtractive process of cDNA r epresentational difference analysis (cRDA), 16 differentially expressed mRN As were isolated and sequenced, revealing 8 known and 8 novel molecules; 15 of these messages were unpreviously reported in microglia. Two markers of all activated microglial EOC cells were identified (iNOS; IRG-1) and specif ic subpopulation markers were highlighted, including molecules known to be closely expressed in perivascular spaces. Moreover, some messages could sup port the distinct morphology, adhesive characteristics, and potential funct ions of the different clones.