Viral Subversion of Organelle-Specific Autophagy

Being obligate intracellular parasites, viruses are known to hijack cellular pathways to promote their life cycle. One such cellular pathway that is frequently subverted by viruses is autophagy. Previously viewed as a non-selective conserved process involving the degradation of old or dysfunctional cytoplasmic contents for recycling, recent evidence suggests that under certain conditions, autophagy can mediate the selective degradation of specific organelles. Indeed, several important human viruses have been shown to exploit organelle-specific autophagy for their benefit. For example, while the human parainfluenza virus type 3 (HPIV3) induces mitophagy to block the type I IFN response, the hepatitis viruses (HCV and HBV) induce mitophagy to attenuate both apoptosis and the host antiviral innate immune response. On the other hand, dengue virus (DENV) and Zika virus (ZIKV) impede ER-phagy to promote their replication. However, the precise signaling pathway(s) that drive the induction of selective autophagy in the context of viral infections is unclear. Thus, understanding the regulation of selective autophagy could advance our knowledge of viral disease pathogenesis.

Although great progress has been made in our understanding of organelle-specific autophagy in the context of viral infections, several important questions remain. For example, how do viruses regulate selective autophagy, and which signaling pathways are involved? What are the key receptors that drive the induction of organelle-specific autophagy? Which type of selective autophagy is more important to viral pathogenesis for viruses that induce more than one type of selective autophagy? How significant is organelle-specific autophagy in viral pathogenesis? Answering these and many other questions may require the development of better tools/markers that are sensitive but specific to selective autophagy. The answers to these questions could broaden our understanding of the relationship between organelle-specific autophagy and viral pathogenesis, and aid in the design of novel therapeutic strategies against these viruses.

This issue aims to highlight the most recent findings on viral interplay with organelle-specific autophagy and will accept both Original Research papers and Reviews related to the topic. The goal is to better understand the role of organelle-specific autophagy in the pathogenesis of viral infections. The themes to be addressed include but are not limited to viral regulation of any of the well-characterized forms of organelle-specific autophagy such as:
• Mitophagy
• Lipophagy
• ER-phagy
• Less characterized forms such as ribophagy in the context of viral infections