IDENTIFICATION OF MOUSE MICROGLIAL CELL SUBPOPULATIONS BY HIGH DIMENSIONAL FLOW CYTOMETRY ANALYSIS IN LPS-INDUCED NEUROINFLAMMATION

PERALTA RAMOS JM; JI MING WANG; PERALTA RAMOS JM; JI MING WANG; CLARISA MANZONE RODRÍGUEZ; BAEZ NATALIA SOLEDAD; CLARISA MANZONE RODRÍGUEZ; BAEZ NATALIA SOLEDAD; DANIELA S. ARROYO; PABLO IRIBARREN; DANIELA S. ARROYO; PABLO IRIBARREN

Congreso; REUNION ANUAL DE SOCIEDADES DE BIOCIENCIAS SAIC SAI SAFIS 2020; 2020

Introduction:Brain-resident microglia and peripheral leukocytes play essential roles in shaping the immune response in the CNS. These cells activate and migrate during active immune responses and may contribute to the progression of neuroinflammation.We previously found that systemic lipopolysaccharide (LPS) challenge induced glial activation and an active recruitment of CD45hi leukocytes, close to vascular endothelial cells, in circumventricular organs. However, the phenotype of microglial cells and the recruited leukocytes were not fully characterized.Methods: In this study, we assessed the phenotype of microglial cells and the recruited leukocytes to the brain, in response to systemic TLR4 stimulation, by applying high dimensional flow cytometryanalysis. We used machine learning algorithms to detect changes in morphology and marker expression in microglia, due to activation by systemic administration of LPS (LPS - 1.6 mg/kg, i.p. injections, n=4). After perfusion, we obtained brain cells suspensions, stained the cells and eight parameters where simultaneously analyzed by conventional flow cytometry and bioinformatics algorithms implemented in R. Results: We detected three populations of microglial cells based on CD45 expression and cell size. After LPS-induced systemic inflammation we observed changes in the microglial cell phenotype and size (p