GPI-80, a beta2 integrin associated glycosylphosphatidylinositol-anchored protein, concentrates on pseudopodia without association with beta2 integrin during neutrophil migration.
Previously, we identified a glycosylphosphatidylinositol (GPI)-anchored protein, designated GPI-80, present on human neutrophils and monocytes. GPI-80 is physically associated with beta2 integrin on the surface of human neutrophils and may be a regulator of neutrophil adherence and migration. However, it is not yet known how GPI-80 regulates cell adhesion and migration. To investigate the physiological role(s) of GPI-80, we examined the topological relationship of GPI-80 and the beta2 integrin subunit (CD18) on resting and migrating human neutrophils by confocal laser microscopy. On resting neutrophils, GPI-80 was evenly distributed on the cell surface and was associated with CD18. On the other hand, during the early phase of migration (5 - 30 minutes), GPI-80 was detected on cell bodies and also on pseudopodia, but CD18 was detected only on cell bodies, where it was associated with GPI-80. In the late phase of migration (60 minutes), GPI-80 was detected only on pseudopodia and its association with CD18 was hardly observed. Furthermore, some of the GPI-80 on pseudopodia of migrating neutrophils during the late phase was associated with urokinase-type plasminogen activator receptor (uPAR), a regulator of beta2 integrin-dependent adherence and migration. The distribution of GPI-80 on cell surfaces is similar to that of uPAR. These observations suggest that GPI-80 belongs to the beta2 integrin-associated GPI-anchored protein family, which has regulatory activity in cell adherence.
Yoshitake
Hiroshi
H
Department of Immunology and Parasitology, Yamagata University School of Medicine, Yamagata, Japan.
Takeda
Yuji
Y
Nitto
Takeaki
T
Sendo
Fujiro
F
Araki
Yoshihiko
Y
D000581:Amidohydrolases; D018821:CD18 Antigens / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002462:Cell Membrane / Q000276:immunology; D002465:Cell Movement; D058851:GPI-Linked Proteins; D006801:Humans; D006867:Hydrolases; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000502:physiology; D011554:Pseudopodia / Q000276:immunology; D011956:Receptors, Cell Surface / Q000378:metabolism; D055293:Receptors, Urokinase Plasminogen Activator
D018821:CD18 Antigens; D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; C524898:PLAUR protein, human; D011956:Receptors, Cell Surface; D055293:Receptors, Urokinase Plasminogen Activator; D009240:N-Formylmethionine Leucyl-Phenylalanine; D006867:Hydrolases; D000581:Amidohydrolases; C121771:VNN2 protein, human