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Updated: Jul 28, 2026
Endothelialized Microfluidics for Studying Microvascular Interactions in Hematologic Diseases
Published on: June 22, 2012
Band 3 peptides block the adherence of sickle cells to endothelial cells in vitro
B J Thevenin1, I Crandall, S K Ballas
1Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
Abstract:
Malaria-parasitized erythrocytes have increased endothelial adherence due to exposure of previously buried intramembranous sites of band 3. Because sickle erythrocytes also show increased adhesiveness and because the membrane portion of band 3 is aggregated in both types of cells, we examined the role of band 3 in sickle cell adhesiveness. Synthetic peptides derived from the second and third exofacial, interhelical regions of band 3 completely inhibited the abnormal adherence of sickle cells to an endothelial monolayer in a static assay. This effect was observed independently of plasma factors, required micromolar levels of peptide, was sequence-specific, and was found with both L- and D-isomers. The active peptides also inhibited the increased adherence induced by low-dose calcium loading of normal red blood cells. Finally, a monoclonal antibody against an active peptide specifically immunostained a fraction of sickle cells. These findings implicate a role for band 3 in at least one type of sickle cell adhesiveness via the exposure of normally cryptic membrane sites.
Insights
Band 3 protein exposure on red blood cells increases adherence in sickle cell disease. Specific peptides targeting Band 3 sites significantly reduced this abnormal cell adhesion, suggesting a key role in the condition.
Area of Science:
- Hematology
- Cell Biology
- Biochemistry
Background:
- Malaria-parasitized erythrocytes exhibit increased endothelial adherence.
- Sickle erythrocytes also display heightened adhesiveness.
- Band 3 protein aggregation occurs in both cell types.
Purpose of the Study:
- Investigate the role of Band 3 protein in sickle cell adhesiveness.
- Determine if Band 3 is responsible for abnormal sickle cell adherence to endothelium.
Main Methods:
- Utilized synthetic peptides derived from Band 3 protein regions.
- Performed static assays with endothelial monolayers and sickle cells.
- Employed a monoclonal antibody for immunostaining sickle cells.
Main Results:
- Specific Band 3 peptides completely inhibited sickle cell adherence.
- Inhibition occurred independently of plasma factors and was sequence-specific.
- Active peptides also reduced calcium-induced adherence in normal red blood cells.
- Immunostaining confirmed Band 3 presence on a fraction of sickle cells.
Conclusions:
- Band 3 protein plays a significant role in sickle cell adhesiveness.
- Exposure of normally cryptic Band 3 membrane sites contributes to abnormal adherence.
- Targeting Band 3 may offer therapeutic potential for sickle cell disease.
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