ALS-linked C9orf72 dipeptide repeats inhibit starvation-induced autophagy through modulating BCL2-BECN1 interaction.

Growing evidences indicate that dysfunction of autophagy contributes to the disease pathogenesis of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), two neurodegenerative disorders. The GGGGCC·GGCCCC repeat RNA expansion in chromosome 9 open reading frame 72 (C9orf72) is the most genetic cause of both ALS and FTD. According to the previous studies, GGGGCC·GGCCCC repeat undergoes the unconventional repeat-associated non-ATG translation, which produces dipeptide repeat (DPR) proteins. Although there is a growing understanding that C9orf72 DPRs have a strong ability to harm neurons and induce C9orf72-linked ALS/FTD, whether these DPRs can affect autophagy remains unclear. In the present study, we find that poly-GR and poly-PR, two arginine-containing DPRs which display the most cytotoxic properties according to the previous studies, strongly inhibit starvation-induced autophagy. Moreover, our data indicate that arginine-rich DPRs enhance the interaction between BCL2 and BECN1/Beclin 1 by inhibiting BCL2 phosphorylation, therefore they can impair autophagic clearance of neurodegenerative disease-associated protein aggregates under starvation condition in cells. Importantly, our study not only highlights the role of C9orf72 DPR in autophagy dysfunction, but also provides novel insight that pharmacological intervention of autophagy using SW063058, a small molecule compound that can disrupt the interaction between BECN1 and BCL2, may reduce C9orf72 DPR-induced neurotoxicity.

Mycobacterial SapM hampers host autophagy initiation for intracellular bacillary survival via dephosphorylating Raptor.

Secreted acid phosphatase (SapM) is an immunomodulator of Mycobacterium tuberculosis (Mtb) and consequently plays a crucial role in disease onset and development upon infection. Importantly, the virulence of SapM has rendered SapM an attractive target for drug development. However, the mechanism underlying the role of SapM in facilitating bacillary survival remains to be fully elucidated. In this context, the present study demonstrated that SapM hampered cellular autophagy to facilitate bacillary survival in mycobacterial-infected macrophages. Mechanically, SapM interacted with Raptor and was localized to the subcellular lysosomal organelle, causing the dephosphorylation of Raptor at the Ser792 position, resulting in mTORC1 hyperactivity and the subsequent autophagy inhibition. Consistent with this, SapM blocked the autophagy initiation and mitigated lung pathology in vivo. These findings highlighted the role of Raptor as a significant substrate of SapM for inhibiting autophagy, which is a novel clue for developing a treatment against tuberculosis.

Mycobacterial Rv1804c binds to the PEST domain of IκBα and activates macrophage-mediated proinflammatory responses.

Recognition of the components of Mycobacterium tuberculosis (Mtb) by macrophages is vital for initiating a cascade of host immune responses. However, the recognition of Mtb-secretory proteins by the receptor-independent pathways of the host remains unclear. Rv1804c is a highly conserved secretory protein in Mtb. However, its exact function and underlying mechanism in Mtb infection remain poorly understood. In the present study, we observed that Rv1804c activates macrophage-mediated proinflammatory responses in an IKKα-independent manner. Furthermore, we noted that Rv1804c inhibits mycobacterial survival. By elucidating the underlying mechanisms, we observed that Rv1804c activates IκBα by directly interacting with its PEST domain. Moreover, Rv1804c was enriched in attenuated but not in virulent mycobacteria and associated with the disease process of tuberculosis. Our findings provide an alternative pathway via which a mycobacterial secretory protein activates macrophage-mediated proinflammatory responses. Our study findings may shed light on the prevention and treatment of tuberculosis.

Genome-Wide CRISPR/Cas9 Screening Identifies That Mitochondrial Solute Carrier SLC25A23 Attenuates Type I IFN Antiviral Immunity via Interfering with MAVS Aggregation.

Activation of the mitochondrial antiviral signaling (MAVS) adaptor, also known as IPS-1, VISA, or Cardif, is crucial for antiviral immunity in retinoic acid-inducible gene I (RIG-I)-like receptor signaling. Upon interacting with RIG-I, MAVS undergoes K63-linked polyubiquitination by the E3 ligase Trim31, and subsequently aggregates to activate downstream signaling effectors. However, the molecular mechanisms that modulate MAVS activation are not yet fully understood. In this study, the mitochondrial solute carrier SLC25A23 was found to attenuate type I IFN antiviral immunity using genome-wide CRISPR/Cas9 screening. SLC25A23 interacts with Trim31, interfering with its binding of Trim31 to MAVS. Indeed, SLC25A23 downregulation was found to increase K63-linked polyubiquitination and subsequent aggregation of MAVS, which promoted type I IFN production upon RNA virus infection. Consistently, mice with SLC25A23 knockdown were more resistant to RNA virus infection in vivo. These findings establish SLC25A23 as a novel regulator of MAVS posttranslational modifications and of type I antiviral immunity.

Chlorpromazine affects autophagy in association with altered Rag GTPase-mTORC1-TFEB signaling.

Autophagy is a critical protein and organelle quality control system, which regulates cellular homeostasis and survival. Growing pieces of evidence suggest that autophagic dysfunction is strongly associated with many human diseases, including neurological diseases and cancer. Among various autophagic regulators, microphthalmia (MiT)/TFE transcription factors, including transcription factor EB (TFEB), have been shown to act as the master regulators of autophagosome and lysosome biogenesis in both physiological and pathological conditions. According to the previous studies, chlorpromazine (CPZ), an FDA-approved antipsychotic drug, affects autophagy in diverse cell lines, but the underlying mechanism remains elusive. In our present study, we find that CPZ treatment induces TFEB nuclear translocation through Rag GTPases, the upstream regulators of mechanistic target of rapamycin complex 1 (mTORC1) signaling. Meanwhile, CPZ treatment also blocks autophagosome-lysosome fusion. Notably, we find a significant accumulation of immature autophagosome vesicles in CPZ-treated cells, which may impede cellular homeostasis due to the dysfunction of the autophagy-lysosome pathway. Interestingly and importantly, our data suggest that the expression of the active form of Rag GTPase heterodimers helps in reducing the accumulation of autophagosomes in CPZ-treated cells, further suggesting a major contribution of the Rag GTPase-mTORC1-TFEB signaling axis in CPZ-induced autophagic impairment.

Human OTUD6B positively regulates type I IFN antiviral innate immune responses by deubiquitinating and stabilizing IRF3.

IMPORTANCE: Interferon (IFN) regulatory factor (IRF3) is one of the key factors for type I IFN transcription. To sophisticatedly regulate type I IFN antiviral immune response, IRF3 activity is closely controlled by a variety of post-translational modifications. However, the regulatory mechanisms are still not fully elucidated. In the present study, we found that human deubiquitinase OTUD6B positively regulates IRF3-mediated antiviral immune response. OTUD6B can stabilize the IRF3 protein level via hydrolyzing (Lys33)-linked polyubiquitin at Lys315. More importantly, mice with OTUD6B overexpression exhibited more resistance to RNA virus infection. Thus, unlike the previous report that zebrafish OTUD6B negatively regulates the antiviral response by suppressing K63-linked ubiquitination of IRF3 and IRF7, we demonstrate that human OTUD6B actually enhances type I IFN response and has the potential for antiviral therapy.

Cardiomyocyte-derived HMGB1 takes a protective role in CVB3-induced viral myocarditis via inhibiting cardiac apoptosis.

Coxsackievirus B3 (CVB3)-induced viral myocarditis (VMC) is characterized by immune cell infiltration and myocardial damage. High mobility group box 1 (HMGB1) is a highly conserved nuclear DNA-binding protein that participates in DNA replication, transcriptional regulation, repair response and inflammatory response in different disease models. To investigate the exact function of HMGB1 in CVB3-induced VMC, we crossed Hmgb1-floxed (Hmgb1f/f ) mice with mice carrying a suitable Cre recombinase transgenic strain to achieve conditional inactivation of the Hmgb1 gene in a cardiomyocyte-specific manner and to establish myocarditis. In this study, we found that cardiomyocyte-specific Hmgb1-deficient (Hmgb1f/f TgCre/+ ) mice exhibited exacerbated myocardial injury. Hmgb1-deficient cardiomyocytes may promote early apoptosis via the p53-mediated Bax mitochondrial pathway, as evidenced by the higher localization of p53 protein in the cytosol of Hmgb1-deficient cardiomyocytes upon CVB3 infection. Moreover, cardiomyocyte Hmgb1-deficient mice are more susceptible to cardiac dysfunction after infection. This study provides new insights into HMGB1 in VMC pathogenesis and a strategy for appropriate blocking of HMGB1 in the clinical treatment of VMC.

Vesicular stomatitis virus-based vaccine targeting plasmodium blood-stage antigens elicits immune response and protects against malaria with protein booster strategy.

Merozoite invasion of the erythrocytes in humans is a key step in the pathogenesis of malaria. The proteins involved in the merozoite invasion could be potential targets for the development of malaria vaccines. Novel viral-vector-based malaria vaccine regimens developed are currently under clinical trials. Vesicular stomatitis virus (VSV) is a single-stranded negative-strand RNA virus widely used as a vector for virus or cancer vaccines. Whether the VSV-based malarial vaccine is more effective than conventional vaccines based on proteins involved in parasitic invasion is still unclear. In this study, we have used the reverse genetics system to construct recombinant VSVs (rVSVs) expressing apical membrane protein 1 (AMA1), rhoptry neck protein 2 (RON2), and reticulocyte-binding protein homolog 5 (RH5), which are required for Plasmodium falciparum invasion. Our results showed that VSV-based viral vaccines significantly increased Plasmodium-specific IgG levels and lymphocyte proliferation. Also, VSV-PyAMA1 and VSV-PyRON2sp prime-boost regimens could significantly increase the levels of IL-2 and IFN-γ-producing by CD4+ and CD8+ T cells and suppress invasion in vitro. The rVSV prime-protein boost regimen significantly increase Plasmodium antigen-specific IgG levels in the serum of mice compared to the homologous rVSV prime-boost. Furthermore, the protective efficacy of rVSV prime protein boost immunization in the mice challenged with P. yoelii 17XL was better compared to traditional antigen immunization. Together, our results show that VSV vector is a novel strategy for malarial vaccine development and preventing the parasitic diseases.

The interaction between E3 ubiquitin ligase Parkin and mitophagy receptor PHB2 links inner mitochondrial membrane ubiquitination to efficient mitophagy.

The autophagic clearance of mitochondria has been defined as mitophagy, which is triggered by mitochondrial damage and serves as a major pathway for mitochondrial homeostasis and cellular quality control. PINK1 and Parkin-mediated mitophagy is the most extensively studied form of mitophagy, which has been linked to the pathogenesis of neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The current paradigm of this particular mitophagy pathway is that the ubiquitination of the outer mitochondrial membrane is the key step to enable the recognition of damaged mitochondria by the core autophagic component autophagosome. However, whether the inner mitochondrial membrane (IMM) is ubiquitinated by Parkin and its contribution to sufficient mitophagy remain unclear. Here, using molecular, cellular, and biochemical approaches, we report that prohibitin 2 (PHB2), an essential IMM receptor for mitophagy, is ubiquitinated by Parkin and thereby gains higher affinity to the autophagosome during mitophagy. Our findings suggest that Parkin directly binds to PHB2 through its RING1 domain and promotes K11- and K33-linked ubiquitination on K142/K200 sites of PHB2, thereby enhancing the interaction between PHB2 and MAP1LC3B/LC3B. Interestingly and importantly, our study allows us to propose a novel model in which IMM protein PHB2 serves as both a receptor and a ubiquitin-mediated base for autophagosome recruitment to ensure efficient mitophagy.

Mycobacterium tuberculosis Rv0790c inhibits the cellular autophagy at its early stage and facilitates mycobacterial survival.

Rv0790c is predicted to be a conserved hypothetical protein encoded by Mycobacterium tuberculosis (Mtb). However, its function in Mtb infection remains largely unknown. In this study, we found that Rv0790c promoted bacillary survival of M. smegmatis (Ms), both in vitro and in vivo. The bacillary burden of Ms exogenously expressing Rv0790c increased, whereas in Rv0790c-knockouts the bacillary burden decreased in infected macrophages. Multiple cellular processes were analyzed to explore the underlying mechanisms. We found that neither inflammatory regulation nor apoptotic induction were responsible for the promotion of bacillary survival mediated by Rv0790c. Interestingly, we found that Rv0790c facilitates mycobacterial survival through cellular autophagy at its early stage. Immunoprecipitation assay of autophagy initiation-related proteins indicated that Rv0790c interacted with mTOR and enhanced its activity, as evidenced by the increased phosphorylation level of mTOR downstream substrates, ULK-1, at Ser757 and P70S6K, at Thr389. Our study uncovers a novel autophagy suppressor encoded by mycobacterial Rv0790c, which inhibits the early stage of cellular autophagy induction upon Mtb infection and takes an important role in maintaining intracellular mycobacterial survival. It may aid in understanding the mechanism of Mtb evasion of host cellular degradation, as well as hold the potential to develop new targets for the prevention and treatment of tuberculosis.

Application of miRNA Biomarkers in Predicting Overall Survival Outcomes for Lung Adenocarcinoma.

Background: With the development of research, the importance of microRNAs (miRNAs) in the occurrence, metastasis, and prognosis of lung adenocarcinoma (LUAD) has attracted extensive attention. This study is aimed at predicting overall survival (OS) results through bioinformatics to identify novel miRNA biomarkers and hub genes. Materials and Methods: The data of LUAD-related miRNA and mRNA samples was downloaded from The Cancer Genome Atlas (TCGA) database. Upon screening and pretreatment of initial data, TCGA data were analyzed using R platform and a series of analytical tools to identify biomarkers with high specificity and sensitivity. Results: 7 miRNAs and 13 hub genes that had strong relation to the overall surviving status were identified in patients with LUAD. The expression of seven miRNAs (hsa-miR-19a-3p, hsa-miR-126-5p, hsa-miR-556-3p, hsa-miR-671-5p, hsa-miR-937-3p, hsa-miR-4664-3p, and hsa-miR-4746-5p) could apparently improve the OS rate of patient with LUAD. The 13 hub genes, namely, CCT6A, CDK5R1, CEP55, DNAJB4, EGLN3, HDGF, HOXC8, LIMD1, MKI67, PCP4L1, PPIL1, SCAI, and STK32A, showed a correlation with the OS status. Conclusion: 7 miRNAs were identified as novel biomarkers for the prognosis of patients with LUAD. This study offered a deeper comprehension of LUAD treatment and prognosis from the molecular level and helped enhance the understanding of the pathogenesis and potential molecular events of LUAD.

A cathelicidin antimicrobial peptide from Hydrophis cyanocinctus inhibits Zika virus infection by downregulating expression of a viral entry factor.

Zika virus (ZIKV) is a re-emerging flavivirus that causes conditions such as microcephaly and testis damage. The spread of ZIKV has become a major public health concern. Recent studies indicated that antimicrobial peptides are an ideal source for screening antiviral candidates with broad-spectrum antiviral activities, including against ZIKV. We herein found that Hc-CATH, a cathelicidin antimicrobial peptide identified from the sea snake Hydrophis cyanocinctus in our previous work, conferred protection against ZIKV infection in host cells and showed preventative efficacy and therapeutic efficacy in C57BL/6J mice, Ifnar1-/- mice, and pregnant mice. Intriguingly, we revealed that Hc-CATH decreased the susceptibility of host cells to ZIKV by downregulating expression of AXL, a TAM (TYRO3, AXL and MERTK) family kinase receptor that mediates ZIKV infection, and subsequently reversed the negative regulation of AXL on host's type I interferon response. Furthermore, we showed that the cyclo-oxygenase-2/prostaglandin E2/adenylyl cyclase/protein kinase A pathway was involved in Hc-CATH-mediated AXL downregulation, and Hc-CATH in addition directly inactivated ZIKV particles by disrupting viral membrane. Finally, while we found Hc-CATH did not act on the late stage of ZIKV infection, structure-function relationship studies revealed that α-helix and phenylalanine residues are key structural requirements for its protective efficacy against initial ZIKV infection. In summary, we demonstrate that Hc-CATH provides prophylactic and therapeutic efficacy against ZIKV infection via downregulation of AXL, as well as inactivating the virion. Our findings reveal a novel mechanism of cathelicidin against viral infection and highlight the potential of Hc-CATH to prevent and treat ZIKV infection.

Depression compromises antiviral innate immunity via the AVP-AHI1-Tyk2 axis.

Depression is a serious public-health issue. Recent reports have suggested higher susceptibility to viral infections in depressive patients. However, how depression affects antiviral innate immune signaling remains unknown. Here, we revealed a reduction in expression of Abelson helper integration site 1 (AHI1) in the peripheral blood mononuclear cells (PBMCs) and macrophages from the patients with major depressive disorder (MDD), which leads to attenuated antiviral immune response. We found that depression-related arginine vasopressin (AVP) induces reduction of AHI1 in macrophages. Further studies demonstrated that AHI1 is a critical stabilizer of basal type-I-interferon (IFN-I) signaling. Mechanistically, AHI1 recruits OTUD1 to deubiquitinate and stabilize Tyk2, while AHI1 reduction downregulates Tyk2 and IFN-I signaling activity in macrophages from both MDD patients and depression model mice. Interestingly, we identified a clinical analgesic meptazinol that effectively stimulates AHI1 expression, thus enhancing IFN-I antiviral defense in depression model mice. Our study promotes the understanding of the signaling mechanisms of depression-mediated antiviral immune dysfunction, and reveals meptazinol as an enhancer of antiviral innate immunity in depressive patients.

Identification of miRNA signature for predicting the prognostic biomarker of squamous cell lung carcinoma.

As explorations deepen, the role of microRNAs (miRNAs) in lung squamous cell carcinoma (LUSC), from its emergence to metastasis and prognosis, has elicited extensive concern. LUSC-related miRNA and mRNA samples were acquired from The Cancer Genome Atlas (TCGA) database. The data were initially screened and pretreated, and the R platform and series analytical tools were used to identify the specific and sensitive biomarkers. Seven miRNAs and 15 hub genes were found to be closely related to the overall survival of patients with LUSC. Determination of the expression of these miRNAs can help improve the overall survival of LUSC patients. The 15 hub genes correlated with overall survival (OS). The new miRNA markers were identified to predict the prognosis of LUSC. The findings of this study offer novel views on the evolution of precise cancer treatment approaches with high reliability.

Importin KPNA2 confers HIV-1 pre-integration complex nuclear import by interacting with the capsid protein.

For human immunodeficiency virus 1 (HIV-1) to infect non-dividing cells, pre-integration complex (PIC) must be transported into the nucleus within the replication cycle. We previously reported that the karyopherin ß1 (KPNB1)-nucleoporin Pom121 pathway, related to the downstream process of PIC nuclear import, mediates efficient HIV-1 PIC nuclear import. Further, our earlier RNA transcriptome sequencing revealed that karyopherin α2 (KPNA2) was among the differentially expressed importin family members during monocyte to macrophage differentiation. Although PIC transport into the nucleus in HIV-1 has been widely studied, much remains to be understood about it. In this study, we confirmed our previous RNA sequencing results and found that HIV-1 replication was significantly lower in 293T cells with siRNA-mediated KPNA2 knockdown and higher in KPNA2-upregulated cells. Quantitative PCR indicated that viral replication was impaired during cDNA nuclear import. The N-terminal of the capsid protein p24 interacted with KPNA2, and KPNB1 participated in KPNA2-mediated PIC nuclear import. Disruption of the capsid-KPNA2 binding by overexpression of full-length p24 or p24 N-terminal impaired the PIC nuclear import. These results indicate that KPNA2 is an important upstream adaptor of the KPNB1-Pom121 axis, thereby mediating HIV-1 PIC nuclear transportation. KPNA2 is thus a potential target for HIV-1 antiviral treatment.

Prognostic Implications of Pyroptosis-Related Gene Signatures in Lung Squamous Cell Carcinoma.

Background: Lung squamous cell carcinoma (LUSC) has been a highly malignant tumor with very poor prognosis. It is confirmed that pyroptosis refers to the deaths of cells in a programmed and inflammatory manner. Nevertheless, the correlation between expression of genes related with pyroptosis and their prognosis remains uncertain in LUSC. Methods: Utilization of The Cancer Genome Atlas (TCGA) cohort has been done for evaluating the prognostics of pyroptosis-related genes for survival and constructing a signature with multiple genes. The least absolute shrinkage and selection operator (LASSO) Cox regression was performed for establishing such pyroptosis-related gene signature. Results: Eventually, identification of 28 genes in relation to pyroptosis was made in LUSC and healthy lung tissues. Upon the basis of these differentially-expressed genes (DEGs), the patients of LUSC can be divided into two subtypes. Nine gene signatures were established using LASSO. The surviving rate for low-risk group was apparently greater in contrast with the high-risk group (p < .001). According to our finding, risk score worked as an independent predictive factor of OS among LUSC sufferers in combination with clinical characteristics. In line with Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses, the enrichment of immunity-related genes and decreasing immunity status among the high-risk group. Conclusion: Genes in relation with pyroptosis played an essential role in tumor immunity, which is capable of predicting the prognosis for LUSCs.

Endogenous cathelicidin is required for protection against ZIKV-caused testis damage via inactivating virons.

Cathelicidins have been shown to effectively inhibit flavivirus replication in vitro. However, the effects of mouse and human endogenous cathelicidins on flavivirus infection in vivo are rarely known. We herein found that mouse endogenous cathelicidin CRAMP was significantly up-regulated upon Zika virus (ZIKV) infection. CRAMP deficiency markedly exacerbated ZIKV replication in testis, and aggravated ZIKV-induced testicular damage and spermatic damage in mice, indicating that endogenous cathelicidin is required for protection against ZIKV-caused male infertility in mice. In vitro antiviral assay showed that both mouse cathelidin CRAMP and human cathelicidin LL-37 obviously reduced ZIKV-caused cytopathic effect and inhibited ZIKV replication in Vero cells. Antiviral mechanism revealed that they both directly inactivated ZIKV virons by binding to ZIKV virons and inducing the leakage of ZIKV genomic RNA, consequently inactivated ZIKV virons. In vivo antiviral assay indicated that both of them effectively inhibited ZIKV replication in C57BL/6J and IFNα/ß receptor-deficient (Ifnar1-/-) mice when CRAMP or LL-37 was intravenously injected in parallel with or at 1 h after intravenous injection of ZIKV, implying that CRAMP and LL-37 effectively inactivated ZIKV particles and exhibited therapeutic potential against ZIKV infection in vivo. Our findings reveal that endogenous cathelicidin CRAMP and LL-37 act as inactivators of ZIKV, and effectively protect against ZIKV replication and ZIKV-induced male infertility, highlighting their potential for therapy of ZIKV infection.

Targeting matrix metalloproteinase MMP3 greatly enhances oncolytic virus mediated tumor therapy.

In cancer, the extracellular matrix is extensively remodeled during chronic inflammation, thus affecting cell transcription, differentiation, migration and cell-cell interactions. Matrix metalloproteinases can degrade the extracellular matrix of tumor tissues and take important roles in disease progression. Numerous efforts to develop cancer treatments targeting matrix metalloproteinases have failed in clinical trials owing to the ineffectiveness and toxicity of the applied inhibitors. In this study, we investigated the potential of targeting matrix metalloproteinases and oncolytic virus combination in cancer therapy. We found that MMP3 expression was upregulated in various cancers and MMP3 expression in the tumor cells, but not in other tissues, was important for tumor growth and metastasis. Single treatment of colon cancer with multiple MMP3 inhibitors was not effective in mice. Nevertheless, the therapeutic effect of MMP3 was greatly improved by combination with an oncolytic virus. A potential mechanism of MMP3 in regulating tumor cell proliferation and invasion was mediated via Erk1/2 an NF-κB signaling. This study reveals that MMP3 is a promising target and the combined treatment with oncolytic virus is a potential strategy for cancer therapy.

Cyclovirobuxine D inhibits dengue virus replication by impeding the complete autophagy in a cholesterol-dependent manner.

Dengue virus (DENV) is the most common mosquito-borne flavivirus, and it affects millions of people globally every year. Currently, there are no approved drugs for the treatment of dengue infection. By screening a natural product library, we identified a novel compound, cyclovirobuxine D (Cvb D), that displays anti-DENV activity. Cvb D inhibits DENV replication in vitro in a dose-dependent manner and protects suckling mice against lethal DENV infection. Mechanistically, Cvb D regulates the expression of genes related to the cellular cholesterol pathway. As a result, Cvb D increases cellular cholesterol synthesis and accumulation, activates mTOR, and inhibits viral-dependent autophagy. Cvb D does not suppress autophagy initiation but impedes the nuclear translocation of the lysosome transcription factor TFEB. In addition, Cvb D restricts the replication of other positive-strand RNA viruses such as Zika virus and Coxsackievirus B3. We speculate that Cvb D could be a broad-spectrum antiviral drug candidate for use against positive-strand RNA viruses that require autophagy for optimal replication.