Compartment Dependence of T‐Lymphocyte Motility

Fresh human T lymphocytes from the blood of healthy individuals exhibited few motile forms, i.e. nonspherical shape and lamellar surface activity, when allowed to settle on a plastic surface. This poor motility of ‘normal’ blood T lymphocytes is most likely physiological, since under the same conditions more than 75% of the blood lymphocytes from T-cell chronic lymphocytic leukaemia (TCLL) cases showed motile forms. In contrast to blood T cells, a large proportion of fresh human splenic T lymphocytes from separate individuals generally showed motile behaviour within 1 h when plated on a substrate. The rate of migration of spleen T cells into a collagen matrix was higher than that of blood T cells. The poor motile behaviour therefore appeared to be a limiting factor for translocation and migration of blood T cells within a collagen matrix. Culture on a collagen matrix at ‘low’ cell density in the presence or absence of serum for 2 days augmented the percentage of motile blood T cells lo the same level as for fresh spleen T cells, whereas culture on plastic caused a relatively moderate increase in motility. This collagen-mediated potentiation probably does not reflect polyclonal T-cell activation, since it occurred in serum-free medium and appeared independent of cell interactions, and since collagen did not induce DNA synthesis. These results demonstrate two major factors regulating the ‘spontaneous’ motility of T lymphocytes, namely the location of the cell within the body and the nature of the substratum.