Old dog, new tricks: Influenza A virus NS1 and in vitro fibrillogenesis

The influenza NS1 protein is involved in suppression of the host immune response. Recently, there is growing evidence that prion-like protein aggregation plays an important role in cellular signaling and immune responses. In this work, we obtained a recombinant, influenza A NS1 protein and showed that it is able to form amyloid-like fibrils in vitro. Using proteolysis and subsequent mass spectrometry, we showed that regions resistant to protease hydrolysis highly differ between the native NS1 form (NS1-N) and fibrillar form (NS1-F); this indicates that significant structural changes occur during fibril formation. We also found a protein fragment that is capable of inducing the process of fibrillogenesis at 37 degrees C. The discovery of the ability of NS1 to form amyloid-like fibrils may be relevant to uncovering relationships between influenza A infection and modulation of the immune response. (C) 2021 Elsevier B.V. and Societe Francaise de Biochimie et Biologie Moleculaire (SFBBM). All rights reserved.

Automated summary

The influenza NS1 protein can form amyloid-like fibrils in vitro, with significant structural changes occurring during fibril formation. A protein fragment capable of inducing fibrillogenesis was also discovered, suggesting a potential relationship between influenza A infection and modulation of the immune response.