The Process of Wrapping Virus Revealed by a Force Tracing Technique and Simulations.

Viral entry into the host cell is the first step of virus infection; however, its dynamic process via endocytosis remains largely elusive. Here, the force tracing technique and single particle simulation are combined to investigate the invagination of single human enterovirus 71 (HEV71, a positive single-stranded RNA virus that is associated with hand, foot, and mouth disease) via cell membranes during its host cell entry. The experimental results reveal that the HEV71 invaginates in membrane vesicles at a force of 58 ± 16 pN, a duration time of 278 ± 68 ms. The simulation further shows that the virus can reach a partially wrapped state very fast, then the upper surface of the virus is covered by the membrane traveling over a long period of time. Combining the experiment with the simulation, the mechanism of membrane wrapping of virus is uncovered, which provides new insights into how the cell is operated to initiate the endocytosis of virus.