EXTRAVASATION OF ANTITUMOR EFFECTOR-CELLS

Development of effective local immune responses depends on the ability of lymphocytes to extravasate and migrate into nonlymphoid solid tissues. Different lymphocyte subpopulations seem to vary in their abilities to extravasate. In this review, recent advances made in understanding lymphocyte extravasation, interactions between lymphocytes and vascular endothelial cells, receptors on lymphocytes which are involved in their movement through the extracellular matrix, and cytokines, which regulate lymphocyte mobility through tissue, are described. In pathologic conditions, lymphocyte extravasation may be compromised, and delivery of immune effector cells to the site of injury is an important therapeutic end point. Adoptive therapy of solid tumors with antitumor effector cells depends on their successful delivery to the tumor. Although parameters which determine this delivery are not yet defined, considerable progress has been made in studies of the mechanisms involved in lymphocyte movement through tissues.