Functional studies on histiocytic and interdigitating reticulum cells from human lymphoid tissue.

Histiocytic (HRC) and interdigitating (IDC) reticulum cells were obtained from human lymphoid tissue (lymph nodes, tonsils), suspended in cell culture medium and cultured. The suspended cells, which were identified by morphological and enzyme histochemical criteria, were studied for surface binding properties for Fc-receptors using erythrocytes coated with IgG. HRC show strong surface binding, IDC, somewhat weaker, but definitely positive surface binding. Both types of reticulum cells possess Fc-receptors; on IDC, however, they are fewer in number and less dense. In connection with recently discovered Fc-receptors on Langerhans cells of the epidermis, functional relationships between blood monocytes, Langerhans cells in skin and IDC in lymphoid tissue are discussed.