Internalization of lymphocyte membrane components.

The functions of lymphocytes, in particular their participation in immune responses, depends on the expression and properties of several molecules that are present on their membranes at different steps in their development and activation. One way to probe this complex and various set of events is to follow the movement of the membrane molecules in different lymphocytes and in different functional conditions and, more specifically, to study their internalization and subsequent fate. In this article, Benvenuto Pernis summarizes the main facts concerning internalization of lymphocyte membrane components, either spontaneous or induced by cross-linking agents, and discusses what they tell us about the physiology of lymphocytes.