Identification of mouse microglial cell subpopulations by high dimensional flow cytometry analysis in LPS-induced neuroinflammation

ARROYO, DS; WANG, JM; PERALTA RAMOS, JM; BAEZ, NS; MANZONE-RODRÍGUEZ, C; RODRIGUEZ, CM; IRIBARREN, P

Congreso; Reunión Anual SAI; 2020

Introduction: Brain-resident microglia and peripheral leukocytesplay essential roles in shaping the immune response in the CNS.These cells activate and migrate during active immune responsesand may contribute to the progression of neuroinflammation.We previously found that systemic lipopolysaccharide (LPS) challengeinduced glial activation and an active recruitment of CD45hileukocytes, close to vascular endothelial cells, in circumventricularorgans. However, the phenotype of microglial cells and the recruitedleukocytes were not fully characterized.Methods: In this study, we assessed the phenotype of microglialcells and the recruited leukocytes to the brain, in response to systemicTLR4 stimulation, by applying high dimensional flow cytometryanalysis. We used machine learning algorithms to detect changes inmorphology and marker expression in microglia, due to activationby systemic administration of LPS (LPS - 1.6 mg/kg, i.p. injections,n=4). After perfusion, we obtained brain cells suspensions, stainedthe cells and eight parameters where simultaneously analyzed byconventional flow cytometry and bioinformatics algorithms implementedin R.Results: We detected three populations of microglial cells basedon CD45 expression and cell size. After LPS-induced systemic inflammationwe observed changes in the microglial cell phenotypeand size (p