Single-cell profiling reveals inflammatory polarization of human carotid versus femoral plaque leukocytes.

Femoral atherosclerotic plaques are less inflammatory than carotid plaques histologically, but limited cell-level data exist regarding comparative immune landscapes and polarization at these sites. We investigated intraplaque leukocyte phenotypes and transcriptional polarization in 49 patients undergoing femoral (n = 23) or carotid (n = 26) endarterectomy using single-cell RNA-Seq (scRNA-Seq; n = 13), flow cytometry (n = 24), and IHC (n = 12). Comparative scRNA-Seq of CD45+-selected leukocytes from femoral (n = 9; 35,265 cells) and carotid (n = 4; 30,655 cells) plaque revealed distinct transcriptional profiles.

Beyond Il-5: Metabolic Reprogramming and Stromal Support Are Prerequisite for Generation and Survival of Long-Lived Eosinophil.

Eosinophils play surprisingly diverse roles in health and disease. Accordingly, we have now begun to appreciate the scope of the functional and phenotypic heterogeneity and plasticity of these cells. Along with tissue-recruited subsets during inflammation, there are tissue resident eosinophil phenotypes with potentially longer life spans and less dependency on IL-5 for survival.

More than neutrophils: Lin(+)Ly6G(+)IL-5Rα(+) multipotent myeloid cells (MMCs) are dominant in normal murine bone marrow and retain capacity to differentiate into eosinophils and monocytes.

Bone marrow is a hematopoietic site harboring multiple populations of myeloid cells in different stages of differentiation. Murine bone marrow eosinophils are traditionally identified by Siglec-F(+) staining using flow cytometry, whereas neutrophils are characterized by Ly6G(+) expression. However, using flow cytometry to characterize bone marrow hematopoietic cells in wild-type mice, we found substantial gray areas in identification of these cells.