. Author manuscript; available in PMC: 2020 Nov 1.

Published in final edited form as: Am J Transplant. 2020 Jan 29;20(5):1225–1235. doi: 10.1111/ajt.15751

TABLE 1.

Surface phenotype, origin, and presumed function of donor and recipient macrophages and monocytes in the heart transplant

	Heart
	Donor		Recipient
	Donor CCR2⁺ macrophage	Donor CCR2⁻ macrophage	Classical recipient monocyte	Nonclassical recipient monocyte
Surface phenotype	CD11b⁺ CD64⁺ CCR2⁺ MHC-II^hi	CD11b⁺ CD64⁺ CCR2⁻ MHC-II^{hi or lo}	CD11b⁺ Ly6G⁻ CD64^int Ly6C^hi CCR2⁺	CD11b⁺ Ly6G⁻ NK1.1⁻ SiglecF⁻ CD64⁻ Ly6C^lo MHCII^lo
Origin	Blood monocytes	Extraembryonic progenitors	Blood monocytes	Blood monocytes
Function	Orchestrate recipient neutrophil and monocyte recruitment	Suppress recipient neutrophil and monocyte recruitment	Differentiate into macrophages and dendritic cells. Contribute to both rejection and tolerance	Unknown. It is thought that nonclassical recipient monocytes do not give rise to tissue macrophages