Two-Dimensional and Three-Dimensional Movement of Human Polymorphonuclear Leu kocytes:Two Fundamentally Different Mechanisms of Location

Patients with an inherited deficiency of the adherence glycoproteins LFA-1, Mac-i, and p150,95 are unable to mobilize polymorphonuclear leukocytes (PMNL5) to peripheral sites of inflammation. LFA-ilMac-i/pi5O,95-deficient PMNL exhibited profoundly impaired movement stimulated by chemotactic factors when the cells were required to move over two-dimensional surfaces. Less impairment of movement was demonstrated in three-dimensional movement through cellulose filters. A possible explanation for this difference in cell translational mobility is that movement in cellulose filters is less adherence dependent than movement over a two-dimensional plastic surface. Movement of PMNL in collagen gels is known to be relatively independent of adherence. No deficiency of translational mobility of PMNL from LFA-llMac-i/p150,95deficient patients was observed in collagen gels. Antibodies against the common beta subunit effectively blocked two-dimensional movement but had little effect on three-dimensional movement through cellulose filters or collagen gel matrices. HL-60 cells were employed as a model to investigate the effects of adherence on cell movement. Treatment of HL-60 cells with phorbol myristate acetate resulted in the appearance of Mac-i and p150,95 on the cell surface. Concurrently, the cells exhibited increased adherence to glass and plastic. In spite of increased adherence, HL-60 cells showed no translational movement, indicating factors other than the ability to adhere were important in cell motility. These experiments implied that PMNLs undergo two fundamentally different kinds of motion, one adherence dependent (two-dimensional movement) and the other largely adherence independent (three-dimensional movement). These findings are consistent with the view that egress of PMNLS from the vascular space is adherence dependent. Movement through extravascular tissues may be adherence independent.