Tyro3 receptor tyrosine kinases in the heterogeneity of apoptotic cell uptake

Mononuclear phagocytes comprise a mobile, broadly dispersed and highly adaptable system that lies at the very epicenter of host defense against pathogens and the interplay of the innate and adaptive arms of immunity. Understanding the molecular mechanisms that control the response of mononuclear phagocytes to apoptotic cells and the anti-inflammatory consequences of that response is an important goal with implications for multiple areas of biomedical sciences. This review details current understanding of the heterogeneity of apoptotic cell uptake by different members of the mononuclear phagocyte family in humans and mice. It also recounts the unique role of the Tyro3 family of receptor tyrosine kinases, best characterized for Mertk, in the signal transduction leading both to apoptotic cell ingestion and the anti-inflammatory effects that result.