Anchorage and lymphocyte function: collagen and the maintenance of motile shape in T cells

When cultured on a collagen matrix at a density of 7 X 10(4) cells/cm2 for 48 hr, 80 +/- 10% of unfractionated and 70 +/- 14% of T-enriched human blood lymphocytes from eight healthy individuals developed a motile morphology defined as the presence of lamellar surface activity and cytoplasmic flattening. During culture on plastic for 48 hr, 32 +/- 5% of unfractionated and 38 +/- 6% of T-enriched lymphocytes from the same individuals developed a motile morphology. The motile morphology was not a rigid state but a series of oscillations in cell shape. The conversion from a spherical into a motile morphology was independent of cell density. After preculture on plastic at 'high' density (1.5 X 10(6) cells/cm2), and subsequent transfer to a plastic surface, 54 +/- 12% of the cells from separate individuals exhibited a motile morphology within 2 hr. These motile forms were, however, transient and approximately 50% disappeared within 12 hr. Collagen augmented the motile behaviour of unfractionated and T-enriched lymphocytes by two to four times when fresh from the blood compared with glass or plastic. During culture on plastic, the lymphocytes lost this prompt responsiveness to collagen contact. Thus, during culture on plastic, the ratio between percentage motile lymphocytes after subsequent transfer to collagen and plastic, respectively decreased from values between 2 and 4 immediately after purification to close to 1 within 2 days. However, when retransferred to collagen, the majority of the lymphocytes within another 2-day period acquired responsiveness to collagen measured as potentiation of motile cell shape on this substrate compared with on plastic. These data suggest that the variation in motile behaviour in the T lymphocyte reflects a labile property which is enhanced by contact with a collagen matrix.