Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock

Circulatory and maturation kinetics of human monocyte subsets in vivo.

Abstract

Monocytes originate fromthe bonemarrow (BM), are distributed in the bloodstream, and can differentiate in the tissue into skin macrophages or intestinal dendritic cells (DCs).1 They play an essential role in the defense against pathogens2 and are implicated in a range of diseases.3 Labeling experiments with 6,6-2H2-glucose4 and 3H-thymidine5,6 have suggested a monocyte residence time in blood of 2 to 4 days. Although these experiments considered monocytes as a single population, the currently held view is that at least 3 monocyte subsets exist: classical CD14++CD16– monocytes (CMs), intermediate CD14+CD16+ monocytes (IMs), and nonclassical CD14+ CD16++ monocytes (NCMs). The residence times of these subsets in blood and their interrelationship remain to be determined.