Chemoattractant receptor signaling and the control of lymphocyte migration.

This review focuses on mechanisms by which chemoattractant receptors activate downstream signaling pathways in lymphocytes. An emphasis is placed on heterotrimeric G protein signaling with a discussion of the specific heterotrimeric G-proteins involved in lymphocyte chemotaxis and motility and the role of regulator of G protein signaling (RGS) proteins in controlling the activation of downstream effectors. Also considered are those direct downstream effectors known to function in lymphocyte chemotaxis and/or motility. The consequences of targeting genes suspected, known, or serendipitously found to be involved in chemokine receptor signaling pathways form much of a basis for the review. When needed for clarification, reference to studies of chemoattractant signaling in model organisms and in neutrophils will be compared and contrasted to studies in lymphocytes. Finally, the emergence of tools to image lymphocyte in vitro and in vivo will be mentioned as they are increasing helpful for the analysis of lymphocyte trafficking and amendable to the study of chemokine receptor signaling.