Quantitative analysis of the effects of vimentin intermediate filaments on the early stages of influenza A virus infection.

Influenza A virus (IAV) hijacks the endocytosis of host cells in the early stages of infection. It is known that microfilaments and microtubules play a vital role in viral infections. However, the potential involvement of intermediate filaments (IFs) and their mechanism in IAV infection are unclear. In this study, we combined quantum dot-based single-virus tracking (QSVT) with conventional biological methods to quantitatively analyze the effects of vimentin IFs on the early stages of IAV infection. The results showed that the knockdown of vimentin did not affect the internalization and motion dynamics of IAV but impacted the transport of IAV to late endosomes. Statistical analysis revealed that the knockdown of vimentin caused more than 20% IAV to remain in the early endosomes after rapid movement than in normal cells and reduced the efficiency of subsequent membrane fusion and genome release. These results suggested that vimentin facilitates IAV infection by participating in the maturation of endosomes. Our study expands the understanding of the mechanism of endocytosis of IAV and fills the gap in the knowledge on vimentin IFs. [ABSTRACT FROM AUTHOR]