Clustering on the forward surfaces of migrating neutrophils of a novel GPI-anchored protein that may regulate neutrophil adherence and migration

We previously reported a novel glycosylphosphatidylinositol (GPI)-anchored glycoprotein (tentatively designated GPI-80) on human leukocytes that may be involved in the regulation of neutrophil adherence and migration. In this study, we examined by immuno- and scanning electron microscopy, the distribution of GPI-80 on neutrophil surfaces. GPI-80 was diffusely distributed on the surface of resting neutrophils and on the peripheral areas of adherent cells after stimulation with N-formyl-methionyl-leucyl-phenylalanine. After longer stimulation (60 min), GPI-80 decreased in number and was again diffusely distributed on the surfaces of round neutrophils. Few GPI-80 were detected on the ventral surfaces of adherent neutrophils. Clusters of GPI-80 were detected on the forward surfaces of neutrophils transmigrating through pores of nitrocellulose membranes. These results may give a morphological background of possible role of GPI-80 for neutrophil extravasation.