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

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Abstract

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. Inflammatory foam cell–like macrophages and monocytes comprised higher proportions of myeloid cells in carotid plaques, whereas noninflammatory foam cell–like macrophages and LYVE1-overexpressing macrophages comprised higher proportions of myeloid cells in femoral plaque (P < 0.001 for all). A significant comparative excess of CCR2+ macrophages in carotid versus plaque was observed by flow cytometry in a separate validation cohort. B cells were more prevalent and exhibited a comparatively antiinflammatory profile in femoral plaque, whereas cytotoxic CD8+ T cells were more prevalent in carotid plaque. In conclusion, human femoral plaques exhibit distinct macrophage phenotypic and transcriptional profiles as well as diminished CD8+ T cell populations compared with human carotid plaques

Authors

Joshua Slysz, Arjun Sinha, Matthew DeBerge, Shalini Singh, Harris Avgousti, Inhyeok Lee, Kristofor Glinton, Reina Nagasaka, Prarthana Dalal, Shaina Alexandria, Ching Man Wai, Ricardo Tellez, Mariavittoria Vescovo, Ashwin Sunderraj, Xinkun Wang, Matthew Schipma, Ryan Sisk, Rishab Gulati, Jenifer Vallejo, Ryosuke Saigusa, Donald M. Lloyd-Jones, Jon Lomasney, Samuel Weinberg, Karen Ho, Klaus Ley, Chiara Giannarelli, Edward B. Thorp, Matthew J. Feinstein