Regulation of human basophil adhesion to endothelium under flow conditions: Different very late antigen 4 regulation on umbilical cord blood-derived and peripheral blood basophils

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Christopher Kepley, Associate Professor (Creator)
Institution
The University of North Carolina at Greensboro (UNCG )
Web Site: http://library.uncg.edu/

Abstract: Background: Although soluble mediators released by basophils in tissue sites contribute to the chronic injury that occurs in hypersensitivity diseases, only limited information is available about how circulating basophils are recruited to tissues. In particular, the interaction of basophils with endothelium under conditions that mimic physiologic flow has not been explored. Objective: We sought to identify adhesion molecules regulating the attachment of human basophils to IL-4-activated human umbilical vein endothelial cells (HUVECs) under flow conditions. Methods: A parallel-plate flow chamber and blocking mAbs were used to define the adhesion molecules involved in the interactions of peripheral blood basophils (PBBs) and cord blood-derived basophils (CBDBs) with IL-4-activated HUVECs and with Chinese hamster ovary (CHO) cell transfectants expressing specific adhesion molecules. A fluorescent ligand specific for very late antigen 4 (VLA-4) was used to directly examine the VLA-4 affinity state of basophils. Results: Flowing PBBs and CBDBs attached to activated HUVECs and to CHO cells expressing P- or E-selectin. However, only CBDBs attached to vascular cell adhesion molecule 1 (VCAM-1)-transfected CHO cells under flow conditions. The attachment of CBDBs to CHO cells was blocked by mAbs directed against E-selectin, P-selectin, and VCAM-1, whereas attachment of PBBs was blocked by E-selectin and P-selectin mAbs. Activating VLA-4 with Mn2+ on PBBs resulted in adhesion to the VCAM-1-transfected CHO cells, indicating that VLA-4 activity on PBBs can be regulated, at least in part, through affinity changes. The Mn2+-induced upregulation of basophil VLA-4 affinity was demonstrated directly by using a fluorescent ligand for VLA-4 and flow cytometry. Conclusions: The interaction of human CBDBs and PBBs with endothelium under flow conditions is mediated in part by both P- and E-selectin. VLA-4 additionally contributes to the adhesion of flowing CBDBs. However, the affinity of VLA-4 is too low to support the adhesion under flow conditions of unstimulated PBBs.

Additional Information

Publication
Journal of Allergy and Clinical Immunology 2002; 110(3):469-75.
Language: English
Date: 2002
Keywords
Mast cells, basophils, adhesion molecules, cell traficking, allergy, inflammation

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