The inducible amphisome isolates viral hemagglutinin and defends against influenza A virus infection

Jumpei Omi,Makoto Yamashita,Atsuo Miyazawa,Tomohiro Miyasaka,Shinichiro Hama,Katsura Igai,Yuri Nishino,Yuki Goto,Kiyotaka Nishikawa,Rieka Nakanishi,Eiko Shimizu,Miho Watanabe-Takahashi,Yasuhiro Natori,Ching-Yi Tseng,Tsuyoshi Waku

doi:10.1038/s41467-019-13974-w

Abstract

The emergence of drug-resistant influenza type A viruses (IAVs) necessitates the development of novel anti-IAV agents. Here, we target the IAV hemagglutinin (HA) protein using multivalent peptide library screens and identify PVF-tet, a peptide-based HA inhibitor. PVF-tet inhibits IAV cytopathicity and propagation in cells by binding to newly synthesized HA, rather than to the HA of the parental virus, thus inducing the accumulation of HA within a unique structure, the inducible amphisome, whose production from the autophagosome is accelerated by PVF-tet. The amphisome is also produced in response to IAV infection in the absence of PVF-tet by cells overexpressing ABC transporter subfamily A3, which plays an essential role in the maturation of multivesicular endosomes into the lamellar body, a lipid-sorting organelle. Our results show that the inducible amphisomes can function as a type of organelle-based anti-viral machinery by sequestering HA. PVF-tet efficiently rescues mice from the lethality of IAV infection.

Highlights

The emergence of drug-resistant influenza type A viruses (IAVs) necessitates the development of novel anti-Influenza A virus (IAV) agents
We screened the tetravalent peptide library for the ability to bind with high affinity to recombinant HA from IAV H1N1 strain A/Puerto Rico/8/1934 (PR8) but not to a related mutant HA with a Leu to Ala amino-acid substitution at residue 194 (HA L194A), which results in complete abolishment of the receptor-binding activity[35]
PVF-tet markedly inhibited the cytopathicity of IAV infection by sequestering newly synthesized HA into the amphisome (Fig. 8)

Summary

Introduction

The emergence of drug-resistant influenza type A viruses (IAVs) necessitates the development of novel anti-IAV agents. We developed a method to screen multivalent peptide libraries to identify tetravalent peptides that can directly bind to a target molecule that functions with a clustering effect, such as Shiga toxin (Stx), a major virulence factor of enterohemorrhagic Escherichia coli[15]. In the trans-Golgi network (TGN) compartments, HA is recruited to the cholesterol-rich membrane domain, generally referred to as a lipid raft, and transported to the apical surface of the plasma membrane via vesicular trafficking[22,23,24] Some intracellular vesicles, such as late endosomes, can fuse with autophagosomes to form the amphisome, an intermediate organelle observed in various type of cells, which subsequently fuses with the lysosome, leading to the degradation of the vesicular contents[25,26,27]

Methods

Results

Conclusion