Opposing cell-type preferences for binding and replication shape influenza A virus infection in human airways.

A study shows influenza A virus tropism in human airways is shaped by both cell-type-specific binding preferences and replication capacity. Avian viruses preferentially bind ciliated cells because of higher apical α2,3-linked sialic acid levels, but replicate at similar levels in both cell types. Human viruses also preferentially bind ciliated cells despite comparable α2,6-linked sialic acid abundance, yet show higher viral RNA and protein levels in secretory cells owing to ANP32 protein compatibility and differences in ANP32A/B expression, resulting in similar infection levels across both cell types.