The migration of activated murine T lymphocytes in vitro. II. Evidence for differential locomotion of T cell subsets.

Lymphocytes that were activated by various means (recovered from an in vivo allograft site, sensitized in mixed lymphocyte culture, or stimulated by Con A in vitro), were extremely motile in vitro when compared to unsensitized lymph node lymphocytes. Allosensitized lymphocytes generated in vitro and in vivo (harvested on days of peak cell-mediated cytotoxicity) were more motile than Con A-activated lymphocytes (harvested on the day of peak thymidine incorporation). Protein (bovine serum albumin, normal mouse serum, or alpha-casein) was chemokinetic for all of the lymphocyte preparations, especially those activated by alloantigen or Con A. When these bulk populations were used, no evidence was found to suggest these materials were chemotactic for activated lymphocytes; the various proteins promoted comparable chemokinetic effects. Treatment of allosensitized lymphocytes generated in vitro with Lyt-2 antisera and complement significantly reduced cell-mediated cytotoxicity, but had no effect on random motility. Conversely, treatment with anti-Lyt-1 antisera and complement impaired the motility of the residual cell population in response to chemokinetic normal mouse serum or alpha-casein. Within the bulk population of lymphocytes allosensitized in vitro, the cells that migrate most quickly are predominantly Thy-1.2, Lyt-1+2-, are not as cytotoxic, and do not incorporate thymidine as actively as the unseparated population. These experiments indicate that subpopulations of lymphocytes demonstrate locomotor heterogeneity. Studies designed to determine if a specific lymphocyte population can manifest directional motility (i.e., chemotaxis) will require the use of various antigen-sensitized lymphocyte clones at defined stages of the cell cycle.