In vitro side-view imaging technique and analysis of human T-leukemic cell adhesion to ICAM-1 in shear flow

Area of Science:

• Biophysics
• Cellular Mechanics
• Adhesion Dynamics

Background:

• Leukocyte adhesion is critical in immune responses and disease.
• Intercellular Adhesion Molecule 1 (ICAM-1) is a key ligand for leukocyte function.
• Understanding cell adhesion mechanics under flow is vital for disease research.

Purpose of the Study:

• To investigate T-leukemic Jurkat cell adhesion to ICAM-1 under shear flow using a novel side-view imaging technique.
• To quantify the dynamic changes in cell-substrate contact length and adhesion time.
• To analyze the influence of shear stress and cell deformability on adhesion mechanics.

Main Methods:

• Utilized a novel side-view imaging technique for in vitro studies.
• Applied shear flow conditions to Jurkat cells on ICAM-1 coated surfaces.
• Employed finite element methods to calculate 3-D flow fields and shear stresses.
• Analyzed cell shapes from in vitro images to determine stress distribution.

Main Results:

• Jurkat cell adhesion to ICAM-1 under flow was observed to be quasistatic.
• Cell-substrate contact length increased initially and then decreased due to membrane peeling.
• Adhesion binding time and contact length were significantly altered by shear stress, cell deformability, and ligand strength.
• Maximum shear stress on the cell body was 3-5 times greater than upstream wall shear stress, influenced by cell deformation.

Conclusions:

• The side-view imaging technique provides a practical assay for studying 3-D cell-surface adhesion mechanics.
• Cell elongation in shear flow mitigates hydrodynamic forces, impacting adhesion transients.
• Findings offer insights into the biophysical mechanisms governing leukocyte adhesion.