SERTAD3 induces proteasomal degradation of ZIKV capsid protein and represents a therapeutic target

Interferon-stimulated gene PVRL4 broadly suppresses viral entry by inhibiting viral-cellular membrane fusion

BACKGROUND

Viral infection elicits the type I interferon (IFN-I) response in host cells and subsequently inhibits viral infection through inducing hundreds of IFN-stimulated genes (ISGs) that counteract many steps in the virus life cycle. However, most of ISGs have unclear functions and mechanisms in viral infection. Thus, more work is required to elucidate the role and mechanisms of individual ISGs against different types of viruses.

RESULTS

Herein, we demonstrate that poliovirus receptor-like protein4 (PVRL4) is an ISG strongly induced by IFN-I stimulation and various viral infections. Overexpression of PVRL4 protein broadly restricts growth of enveloped RNA and DNA viruses, including vesicular stomatitis virus (VSV), herpes simplex virus 1 (HSV-1), influenza A virus (IAV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) whereas deletion of PVRL4 in host cells increases viral infections. Mechanistically, it suppresses viral entry by blocking viral-cellular membrane fusion through inhibiting endosomal acidification. The vivo studies demonstrate that Pvrl4-deficient mice were more susceptible to the infection of VSV and IAV.

CONCLUSION

Overall, our studies not only identify PVRL4 as an intrinsic broad-spectrum antiviral ISG, but also provide a candidate host-directed target for antiviral therapy against various viruses including SARS-CoV-2 and its variants in the future.

A review on Zika vaccine development

Zika virus (ZIKV), which belongs to the Flavivirus family, is mainly transmitted via the bite of Aedes mosquitoes. In newborns, ZIKV infection can cause severe symptoms such as microcephaly, while in adults, it can lead to Guillain‒Barré syndrome (GBS). Due to the lack of specific therapeutic methods against ZIKV, the development of a safe and effective vaccine is extremely important. Several potential ZIKV vaccines, such as live attenuated, inactivated, nucleic acid, viral vector, and recombinant subunit vaccines, have demonstrated promising outcomes in clinical trials involving human participants. Therefore, in this review, the recent developmental progress, advantages and disadvantages of these five vaccine types are examined, and practical recommendations for future development are provided.

The aldehyde dehydrogenase ALDH1B1 exerts antiviral effects through the aggregation of the adaptor MAVS

Type I interferons (IFNs) are produced by almost all cell types and play a vital role in host defense against viral infection. Infection with an RNA virus activates receptors such as RIG-I, resulting in the recruitment of the adaptor protein MAVS to the RIG-I-like receptor (RLR) signalosome and the formation of prion-like functional aggregates of MAVS, which leads to IFN-β production. Here, we identified the aldehyde dehydrogenase 1B1 (ALDH1B1) as a previously uncharacterized IFN-stimulated gene (ISG) product with critical roles in the antiviral response. Knockout of ALDH1B1 increased, whereas overexpression of ALDH1B1 restricted, the replication of RNA viruses, such as vesicular stomatitis virus (VSV), Zika virus (ZIKV), dengue virus (DENV), and influenza A virus (IAV). We found that ALDH1B1 localized to mitochondria, where it interacted with the transmembrane domain of MAVS to promote MAVS aggregation. ALDH1B1 was recruited to MAVS aggregates. In addition, ALDH1B1 also enhanced the interaction between activated RIG-I and MAVS, thus increasing IFN-β production and the antiviral response. Furthermore, Aldh1b1-/- mice developed more severe symptoms than did wild-type mice upon IAV infection. Together, these data identify an aldehyde dehydrogenase in mitochondria that functionally regulates MAVS-mediated signaling and the antiviral response.