Human cord blood-derived large myeloid cells: spontaneous shape change and chemotactic movement

We have demonstrated two aspects of the movement of large myeloid cells derived from cord blood mononuclear cells after culture in RPMI 1640 and 10% fetal calf serum for eight days. At this time cells assume various shapes including round, oval, veiled, elongated and dendritic. Interestingly, these shapes were not static. Time-lapse recording demonstrated that individual cells change shape quite dramatically over four hours. Some of the veils showed a great deal of activity, some elongated cells shrank into rounded forms, and rounded cells stretched out into dendritic cells or elongated forms. We have previously shown that the number of N-formyl-methionine-leucyl-phenylalanine receptors on the cell surface increase with culture time up to eight days. Furthermore, a rise in Ca2+ was observed in response to 1 mumol/L N-formyl-methionine-leucyl- phenylalanine (chemotactic peptide) at the single cell level. In this paper we show the motility of cord blood-derived myeloid cells towards a chemotactic peptide concentration gradient leaking from a micropipette.