Cultivation and characterization of macrophages from murine embryonic skin. Are they Langerhans cells?

We have observed a population of trypsin-resistant adherent cells in long-term primary cultures of murine embryonic skin. These cells were subsequently demonstrated to share a variety of characteristics with cells of the monocyte/macrophage lineage. The trypsin-resistant adherent cells stained positively for nonspecific esterase, exhibited surface receptors for Fc-IgG, and complement components as well as strong phagocytic activity. Additionally, these cells exhibited membrane ATPase enzyme activity and a large proportion of the cells expressed la antigens as detected by cytotoxicity and membrane fluorescence. The possible relationship between these trypsin-resistant adherent cells and Langerhans cells of the skin is discussed.