Nonclassical Monocytes in Health and Disease

Monocytes are innate blood cells that maintain vascular homeostasis and are early responders to pathogens in acute infections. There are three well-characterized classes of monocytes: classical (CD14 + CD16 − in humans and Ly6C hi in mice), intermediate (CD14 + CD16 + in humans and Ly6C + Treml4 + in mice), and nonclassical (CD14 − CD16 + in humans and Ly6C lo in mice). Classical monocytes are critical for the initial inflammatory response. Classical monocytes can differentiate into macrophages in tissue and can contribute to chronic disease. Nonclassical monocytes have been widely viewed as anti-inflammatory, as they maintain vascular homeostasis. They are a first line of defense in recognition and clearance…

• NI
  National Institutes of Health