Membrane tension determines the geometry of donut-shaped transcellular holes

Bacteria and leukocytes employ donut-shaped transcellular holes in plasma membrane to cross the endothelial barrier. How these fused holes are regulated in a double-bilayer system is currently poorly understood. Here we use membrane physics to present a universal relationship that determines the geometry of the donut-shaped holes. Our study reveals that hole radius is determined by plasma membrane tension via a commonly used critical length scale root kappa/lambda defined by flexural stiffness (kappa) and in-plane tension (lambda). This relationship suggests that the hole diameter increases with a reduction in membrane tension, a finding aligned with the experimental observations but in contrast with the main current model in the literature.

Automated summary

The study found that plasma membrane tension affects the geometry of donut-shaped holes through a relationship with a critical length scale, with the hole diameter increasing with a reduction in membrane tension. This finding is aligned with experimental observations, but contrasts with the main current model in the literature.