Lymphocyte locomotion "in vitro": the role of growth activators and chemoattractants.

Studies of lymphocyte locomotion in vitro are reviewed. This locomotion is important (a) for recirculation and the traversing of high endothelial venules in lymphoid tissue; (b) for recruitment of lymphocytes into inflammatory sites. In the latter situation, activated lymphocytes migrate more actively than resting lymphocytes. Our studies indicate that lymphocyte activators such as PHA, anti-CD3 antibodies, or the Cowan staphylococcus confer locomotor capacity on populations of human blood lymphocytes which, in the resting state, are immotile. Locomotor capacity is acquired in the G1 phase of growth and requires protein and RNA synthesis but not DNA synthesis. Anti-CD3-driven locomotor activation is inhibited by cyclosporin A, suggesting that new gene expression is required. The mitogens do not act directly as locomotor stimulants, i.e. they are not themselves chemotactic or chemokinetic factors. Rather they activate the potential for motility of lymphocytes and also cause release of lymphokines which are the direct stimulants for locomotion. One of these lymphokines (lymphocyte chemotactic factor: LCF) has been partially characterized.