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CD66a, CD66b, CD66c, and CD66d each independently stimulate neutrophils
K M Skubitz1, K D Campbell, A P Skubitz
1Department of Medicine, University of Minnesota Medical School, Minneapolis, USA.
Journal of Leukocyte Biology
|July 1, 1996
Summary
Antibodies targeting CD66a, CD66b, CD66c, and CD66d on neutrophils increase cell adhesion. This process requires extracellular calcium and involves the CD11/CD18 molecule, suggesting a role in neutrophil activation signaling.
Area of Science:
- Immunology
- Cell Biology
Background:
- Four members of the carcinoembryonic antigen family (CD66a, CD66b, CD66c, and CD66d) are expressed on human neutrophils.
- These CD66 antigens are considered activation molecules, as their surface expression intensifies upon cell stimulation.
Purpose of the Study:
- To investigate the role of CD66 antigens in neutrophil signaling pathways.
- To determine the effect of CD66 antibody binding on neutrophil adhesion to endothelial cells.
Main Methods:
- Utilized a panel of well-characterized CD66 monoclonal antibodies (mAbs).
- Assessed the impact of these antibodies on neutrophil adhesion to human umbilical vein endothelial cells (HUVECs).
- Investigated the role of extracellular calcium and CD18/CD11 molecules in the observed adhesion changes.
Main Results:
- CD66a, CD66b, CD66c, and CD66d antibodies individually enhanced neutrophil adhesion to HUVECs.
- This enhanced adhesion was dependent on extracellular calcium and mediated by the CD11/CD18 complex, indicated by blockage with a CD18 antibody and CD11/CD18 upregulation.
- Signal transduction initiated by CD66 antibody binding is transient, calcium-dependent, and can be independently transmitted by each CD66 antigen.
Conclusions:
- CD66 antibody binding triggers a calcium-dependent signaling cascade in neutrophils.
- This signaling pathway modulates the adhesive properties of the CD11/CD18 integrin, influencing neutrophil-endothelial cell interactions.
- Each CD66 antigen (CD66a, CD66b, CD66c, CD66d) can independently initiate signaling within neutrophils.