TNK2/ACK1 Strengthen Influenza A Virus Infection by Blocking Viral Matrix 2 Protein(M2) into Lysosome to Degradation

Abstract BackgroundTNK2/ACK1, a non-receptor tyrosine kinase, plays critical roles in signalling transduces and trafficking. Our previous genome-wide CRISPR/CAS9 knockout screen revealed that mutant of TNK2 produced more restrict to influenza virus infection. In this study, we aim to illustrate the role of TNK2 for influenza A virus (IAV) replication in human cells.ResultsCRISPR/Cas9-mediated mutant of TNK2 resulted in a significant reduction in viral proteins expression and viral titres for multiple influenza strains, and furthermore, a decrease of nuclear import of IAV in the infected TNK2 mutant cells was observed in 3h post-infection. Interestingly, TNK2 mutation enhanced the colocalization of LC3 with autophagic receptor p62 and led to the attenuation of influenza virus-caused accumulation of autophagosomes in TNK2 mutant cells. Further, confocal microscopy visualization result showed that influenza viral matrix 2 (M2) was colocalized with Lamp1 in the infected TNK2 mutant cells in early infection, while almost no colocalization between M2 and Lamp1 was observed in IAV-infected wild-type cells. Moreover, TNK2 depletion also affected the trafficking of early endosome and the movement of influenza viral NP and M2.ConclusionsOur results identified TNK2 as a critical host factor for influenza viral M2 protein trafficking, suggesting that TNK2 will be an attractive target for the development of antivirals therapeutics.