Apoptosis and Autophagy in Picornavirus Infection.

Di Sun,Renyong Jia,Sai Mao,Dekang Zhu,Zhiwen Xu,Xiaoyao Yang,Shaqiu Zhang,Yunya Liu,Ling Zhang,Ying Wu,Mafeng Liu,Zhengli Chen,Xinxin Zhao,Yin Wang,Xiaoyue Chen,Shun Chen,Anchun Cheng,Qiao Yang,Yanling Yu,Mingshu Wang,Xingjian Wen,Ling Zhu,Qihui Luo

doi:10.3389/fmicb.2019.02032

Abstract

Cell death is a fundamental process in maintaining cellular homeostasis, which can be either accidental or programed. Programed cell death depends on the specific signaling pathways, resulting in either lytic or non-lytic morphology. It exists in two primary forms: apoptosis and autophagic cell death. Apoptosis is a non-lytic and selective cell death program, which is executed by caspases in response to non-self or external stimuli. In contrast, autophagy is crucial for maintaining cellular homeostasis via the degradation and recycling of cellular components. These two mechanisms also function in the defense against pathogen attack. However, picornaviruses have evolved to utilize diverse strategies and target critical components to regulate the apoptotic and autophagic processes for optimal replication and the release from the host cell. Although an increasing number of investigations have shown that the apoptosis and autophagy are altered in picornavirus infection, the mechanism by which viruses take advantage of these two processes remains unknown. In this review, we discuss the mechanisms of picornavirus executes cellular apoptosis and autophagy at the molecular level and the relationship between these interactions and viral pathogenesis.

Highlights

Picornaviruses are divided into 47 genera and are known for causing a wide variety of diseases, including numerous human and animal pathogens (Zell et al, 2017)
Known as two critical processes contributing to the maintenance of cellular homeostasis, autophagy controls the turnover of organelles and proteins within cells, and apoptosis is the principal mechanism by which unwanted or abnormal cells are physiologically eliminated from organisms
Apoptosis is a non-inflammatory type of programed cell death (PCD) and requires a cascade of signaling proteins to respond to the activation of a death signal

Summary

INTRODUCTION

Picornaviruses are divided into 47 genera and are known for causing a wide variety of diseases, including numerous human and animal pathogens (Zell et al, 2017). The ORF is translated into a polyprotein, which is proteolytically processed into individual viral proteins containing VP1, VP2, VP3, VP4, leader proteinase (in the genus Aphthovirus), 2A, 2B, 3A, 3B, 3C, and 3D These mature and functional proteins participate in viral translation, transcription, replication, assembly, and release. To favor viral replication and propagation, picornaviruses selectively alter cellular pathways, such as, by inducing the shutoff of host protein translation, inhibiting the immune response and modulating cell death processes. These processes are mostly achieved by viral non-structural proteins, especially proteinase, including 2A protease and 3C protease. An increasing of investigations has demonstrated that non-enveloped picornaviruses can adopt a non-lytic transmission strategy via vesicles, which require autophagy to form double-membrane autophagosomes carrying virions to the extracellular environment (Feng et al, 2013)

Introduction to Apoptosis

References proteases

CONCLUSION