Expression of XCR1, CX3CR1, CSF1R and ADGRE1 on subsets of bovine blood dendritic cells and monocytes

Abstract

Among dendritic cells (DC) and monocytes in blood of cattle we can distinguish conventional and plasmacytoid DC (cDC1, cDC2, pDC) and classical, intermediate and nonclassical monocytes (cM, intM, ncM), respectively. Phenotypic definitions of subsets rely on combinations of only a few markers such as CD13 and CD4 for Flt3+ dendritic cells, and CD14 and CD16 for CD172ahigh monocytes. Additional reagents for flow cytometry are urgently needed to refine these phenotypic classifications and account for heterogeneity of these cells, in particular cDC2 and intM. In the current study we have investigated expression of CX3CR1 and ADGRE1 on bovine blood DC and monocyte subsets, and have tested two newly generated bovine recombinant proteins (XCL1 and CSF1) for staining of XCR1 and CSF1R. Staining patterns obtained by multicolor flow cytometry of peripheral blood mononuclear cells from two cows were largely in line with gene expression data available from a previous study (bulk RNA-seq of sorted DC and monocyte subsets from bovine blood).