Environment-driven active transport of influenza A virus
Biological media such as airway mucus and extracellular matrix are usually viewed as transport barriers that particles cross by passive diffusion or with internal engines. We show instead that a particle can move actively by modifying the landscape it traverses, creating environmental memory and directional cues in two and three dimensions. Influenza A virus (IAV) realizes this principle through its envelope proteins hemagglutinin (HA) and neuraminidase (NA), which bind and cleave sialylated glycan receptors, respectively. Combining theory, simulations and single-virus tracking, we connect bind--cleave kinetics and HA--NA organization to macroscopic transport. Cleavage dissipates chemical free energy, biases rebinding to the edited landscape and leaves a trail that shapes future encounters. In heterogeneous receptor landscapes, multivalent binding biases motion toward higher receptor density, while receptor destruction by NA can amplify this bias by sharpening the contrast sampled by HA. Experiments on reconstituted glycan membranes show that IAV steps are biased up local receptor gradients, as predicted. The theory suggests that virion-to-virion variability can distribute transport functions across a population, providing a physical hedge against complex receptor environments. Together, these results establish environment-driven active matter as a mechanism for motorless transport powered and guided by chemical modification of the environment.