Locomotor phenotypes of unstimulated CD45RAhigh and CD45ROhigh CD4+ and CD8+ lymphocytes in three-dimensional collagen lattices.

The spontaneous locomotion of immunomagnetically isolated resting CD4+ and CD8+ lymphocytes in three-dimensional collagen gels was recorded by time-lapse videomicroscopy. Two-dimensional projections of the paths of randomly selected individual cells were digitized, plotted and quantitatively analysed. Among five different donors 46 +/- 10% of CD4+ and CD8+ lymphocytes (n = 180) showed initial spontaneous locomotion (individual speed 5-25 microns/min; mean speed CD4+ 5.2 +/- 3.6 microns, CD8+ 3.23 +/- 2.72 microns). Active CD4+ cells were constantly migrating for more than 4 hr, whereas CD8+ lymphocytes significantly slowed down after 60-90 min in the collagen gel (P < 0.003). Quantitative analysis of the paths indicated at least three migratory phenotypes: (1) spontaneously locomoting cells exhibiting high speed and low frequency of stopping; (2) a major non-motile fraction without significant displacement; and (3) a subpopulation within CD4+ and CD8+ cells with intermediate activity of speed and stopping. Further subtype analysis of immunomagnetically isolated CD45RAhigh/ROlow or CD45RAlow/ROhigh lymphocytes showed that more than 90% of CD4+ CD45RAhigh/ROlow cells were actively locomoting. In contrast, only 20% of the CD4+ CD45ROhigh/RAlow phenotype showed spontaneous motility to a limited degree. The data indicate that resting CD4+ and CD8+ lymphocytes comprise further locomotory subpopulation related to the expression of different CD45 isoforms.