Impaired adhesion of neutrophils expressing Slc44a2/HNA-3b to VWF protects against NETosis under venous shear rates.

Abstract

Genome-wide association studies linked expression of the human neutrophil antigen 3b (HNA-3b) epitope on the Slc44a2 protein with a 30% decreased risk of venous thrombosis (VT) in humans. Slc44a2 is a ubiquitous transmembrane protein identified as a receptor for von Willebrand factor (VWF). To explain the link between Slc44a2 and VT, we wanted to determine how Slc44a2 expressing either HNA-3a or HNA-3b on neutrophils could modulate their adhesion and activation on VWF under flow. Transfected HEK293T cells or neutrophils homozygous for the HNA-3a- or HNA-3b-coding allele were purified from healthy donors and perfused in flow chambers coated with VWF at venous shear rates (100 s-1). HNA-3a expression was required for Slc44a2-mediated neutrophil adhesion to VWF at 100 s-1. This adhesion could occur independently of β2 integrin and was enhanced when neutrophils were preactivated with lipopolysaccharide. Moreover, specific shear conditions with high neutrophil concentration could act as a "second hit," inducing the formation of neutrophil extracellular traps. Neutrophil mobilization was also measured by intravital microscopy in venules from SLC44A2-knockout and wild-type mice after histamine-induced endothelial degranulation. Mice lacking Slc44a2 showed a massive reduction in neutrophil recruitment in inflamed mesenteric venules. Our results show that Slc44a2/HNA-3a is important for the adhesion and activation of neutrophils in veins under inflammation and when submitted to specific shears. The fact that neutrophils expressing Slc44a2/HNA-3b have a different response on VWF in the conditions tested could thus explain the association between HNA-3b and a reduced risk for VT in humans.

• Authors: Gaïa Zirka, Philippe Robert, Julia Tilburg, Victoria Tishkova, Chrissta X Maracle, Paulette Legendre, Bart J M van Vlijmen, Marie-Christine Alessi, Peter J Lenting, Pierre-Emmanuel Morange, Grace M Thomas
• Journal: Blood (Blood) Vol. 137 Issue 16 Pg. 2256-2266 (04 22 2021) ISSN: 1528-0020 [Electronic] United States
• PMID: 33556175 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2021 by The American Society of Hematology.

Chemical References

• HNA-3b antigen, human
• Isoantigens
• Membrane Glycoproteins
• Membrane Transport Proteins
• SLC44A2 protein, human
• von Willebrand Factor

Topics

• Animals
• Blood Circulation
• Cell Adhesion
• Cells, Cultured
• Extracellular Traps (genetics, metabolism)
• Gene Expression
• HEK293 Cells
• Humans
• Isoantigens (genetics, metabolism)
• Male
• Membrane Glycoproteins (genetics, metabolism)
• Membrane Transport Proteins (genetics, metabolism)
• Mice, Inbred C57BL
• Neutrophils (cytology, metabolism)
• Venous Thrombosis (genetics, metabolism)
• von Willebrand Factor (metabolism)
• Mice