Related Experiment Video
Updated: Feb 27, 2026
12:42
Human Neutrophil Flow Chamber Adhesion Assay
Published on: July 2, 2014
17.8K
Neutrophils can adhere via alpha4beta1-integrin under flow conditions
P H Reinhardt1, J F Elliott, P Kubes
1Immunology Research Group, University of Calgary, Alberta, Canada.
Blood
|May 15, 1997
Summary
Neutrophils can recruit via an alternative alpha4beta1-integrin pathway, independent of beta2-integrin, to tumor necrosis factor alpha-stimulated endothelium. This challenges the notion that alpha4beta1 is exclusive to mononuclear leukocytes.
Area of Science:
- Immunology
- Cell Biology
- Biochemistry
Background:
- Neutrophil recruitment is crucial for inflammatory responses.
- Traditionally, beta2-integrin pathways are considered primary for neutrophil adhesion.
- The role of alpha4beta1-integrin in neutrophil function has been largely unexplored.
Purpose of the Study:
- To investigate the potential of an alternative alpha4beta1-integrin-dependent pathway for neutrophil recruitment.
- To determine if neutrophils can tether, roll, and adhere to activated endothelium via alpha4beta1.
- To assess the functional significance of alpha4beta1-integrin on human neutrophils.
Main Methods:
- Utilized a parallel plate chamber to study neutrophil-endothelium interactions under shear force.
- Induced alpha4beta1-integrin expression on neutrophils using dihydrocytochalasin B and chemotactic agents.
- Employed antibodies against alpha4 and beta1-integrin subunits and antiselectin therapy to block specific adhesion molecules.
- Investigated interactions with VCAM-1 and ICAM-1 transfected L cells, and fibronectin under static and shear conditions.
Main Results:
- Neutrophils expressing alpha4beta1-integrin demonstrated stable adhesion to TNF alpha-stimulated endothelium, independent of beta2-integrin.
- This firm adhesion was abolished by anti-alpha4 or anti-beta1 antibodies, confirming alpha4beta1 involvement.
- Rolling interactions were dependent on selectins, not alpha4beta1.
- Neutrophils tethered and adhered to VCAM-1-transfected cells via alpha4beta1 under low shear stress.
- Adhesion to fibronectin occurred only under static conditions.
Conclusions:
- Neutrophils can adhere via an alpha4beta1-integrin pathway, distinct from the beta2-integrin pathway, under specific conditions.
- The alpha4beta1-integrin is functional on human neutrophils, mediating adhesion to VCAM-1 and fibronectin.
- This finding refutes the exclusive role of alpha4beta1 in mononuclear leukocyte adhesion and expands our understanding of neutrophil recruitment mechanisms.
More Related Videos
11:22Quantitative In vitro Assay to Measure Neutrophil Adhesion to Activated Primary Human Microvascular Endothelial Cells under Static Conditions
Published on: August 23, 2013
18.0K
08:54Isolation of Human Umbilical Vein Endothelial Cells and Their Use in the Study of Neutrophil Transmigration Under Flow Conditions
Published on: August 8, 2012
17.9K
Related Concept Videos
01:24Adherens Junctions
6.9K
Strong contact points between adjacent cells anchor them to each other, forming tissues. Such anchoring junctions are of two types – adherens junctions and desmosomes. Adherens junctions are abundant in tissues such as epithelium and endothelium, forming a continuous zone of adhesion called the adhesion belt. In other tissues, such as heart muscle, they appear as clusters, linking the cells to produce coordinated heart muscle contraction.
Adherens Junctions are Dynamic
Adherens Junctions are Dynamic
6.9K
01:10Integrins
5.8K
Animal and protozoan cells do not have cell walls to help maintain shape and provide structural stability. Instead, these eukaryotic cells secrete a sticky mass of carbohydrates and proteins into the spaces between adjacent cells. This network of proteins and molecules is called an extracellular matrix or ECM.
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
Some ECM proteins assemble into a basement membrane to which the remaining components adhere. Proteoglycans typically form the bulk of the ECM while fibrous proteins, like collagen,...
5.8K
01:25Selectins
4.6K
Cell adhesion is an essential aspect of multicellularity. While stable cell interactions usually occur between cells of the same type, transient cell interactions occur between cells of different tissue types, such as between neutrophils and endothelial cells. Selectins are one class of cell adhesion molecules (CAMs) that bind carbohydrate ligands to form transient cell adhesion. They are rod-like proteins with a long extracellular part of variable length ending with the lectin domain,...
4.6K
01:17Intracellular Signaling Affects Focal Adhesions
3.7K
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
3.7K
01:15Activation of Integrins
5.3K
Integrins bind ligands and transmit information from outside the cell to inside or vice-versa through an "outside-in signaling" or "inside-out signaling."
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
In "outside-in signaling," external factors in the extracellular space bind to exposed ligand binding sites on integrins. This causes the inactive protein to undergo a conformational change to become active. Integrins are often clustered on the cell membrane. Repetitive and regularly spaced ligand binding...
5.3K