Redistribution of P-selectin glycoprotein ligand-1 (PSGL-1) in chemokine-treated neutrophils: a role of lipid microdomains.
P-selectin glycoprotein ligand-1 (PSGL-1) is a mucin-like cell adhesion molecule expressed on leukocyte plasma membranes and involved in platelet-leukocyte and endothelium-leukocyte interactions. The treatment of neutrophils with a low concentration of IL-8 induced the redistribution of PSGL-1 to one end of the cell to form a cap-like structure. We investigated the role of lipid microdomains in the redistribution of PSGL-1 and its effect on the adhesive characteristics of IL-8-treated neutrophils. The redistribution of PSGL-1 induced by IL-8 was inhibited by cholesterol-perturbing agents such as methyl-beta-cyclodextrin and filipin. Sucrose density gradient centrifugation analysis revealed that PSGL-1 was enriched in a low-density fraction together with the GM1 ganglioside after solubilization of the cell membranes with a nonionic detergent, Brij 58. However, when Triton X-100 was used for the solubilization, PSGL-1 was no longer recovered in the low-density fraction, although GM1 ganglioside remained in the low-density fraction. Furthermore, immunofluorescence microscopic observation demonstrated that the localization of PSGL-1 differed from that of GM1 ganglioside, suggesting that PSGL-1 is associated with a microdomain distinct from that containing the GM1 ganglioside. Treatment of neutrophils with IL-8 increased the formation of microaggregates composed of neutrophils and activated platelets, and this treatment also enhanced reactive oxygen species production in neutrophils induced by the cross-linking of PSGL-1 with antibodies. These results suggest that the association of PSGL-1 with lipid microdomains is essential for its redistribution induced by IL-8 stimulation and that the redistribution modulates neutrophil functions mediated by interactions with P-selectin.
Itoh
Saotomo
S
Department of Microbiology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, Tokyo 142-8501, Japan.
Susuki
Chie
C
Takeshita
Kana
K
Nagata
Kisaburo
K
Tsuji
Tsutomu
T
D001792:Blood Platelets / Q000502:physiology; D002448:Cell Adhesion; D016764:Cell Polarity; D002784:Cholesterol / Q000378:metabolism; D005372:Filipin / Q000494:pharmacology; D005677:G(M1) Ganglioside / Q000378:metabolism; D006801:Humans; D006861:Hydrogen Peroxide / Q000378:metabolism; D066298:In Vitro Techniques; D016209:Interleukin-8 / Q000494:pharmacology*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D021962:Membrane Microdomains / Q000502:physiology*; D009504:Neutrophils / Q000502:physiology*; D015539:Platelet Activation; D021381:Protein Transport; D017382:Reactive Oxygen Species / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000494:pharmacology
D016209:Interleukin-8; D008562:Membrane Glycoproteins; C084882:P-selectin ligand protein; D017382:Reactive Oxygen Species; D047392:beta-Cyclodextrins; C108732:methyl-beta-cyclodextrin; D005677:G(M1) Ganglioside; D005372:Filipin; D002784:Cholesterol; D006861:Hydrogen Peroxide