Project description:The mechanisms responsible for the molecular pathogenesis of the highly pathogenic avian influenza virus (HPAIV) or low pathogenic avian influenza virus (LPAIV) in avian species remain poorly understood. Thus, global immune response of chickens infected with HPAIV H5N1 (A/duck/India/02CA10/2011) and LPAIV H9N2 (A/duck/India/249800/2010) viruses was studied using microarray to identify crucial host genetic components responsive to these infection. HPAIV H5N1 induced excessive mRNA expression of cytokines (IFNA, OASL, MX1, RSAD2, IFITM5, GBP 1, IL1B, IL18, IL22, IL13, IL12B, CCL4, CCL9, CCL10, CX3CL1 etc) in lung tissues. This excessive cytokine response (cytokine storms) may cause tissue damage and high mortality in chickens. In contrast, the expression levels of most of the cytokines remained unchanged in the lungs of LPAIV H9N2 virus infected chickens. This study indicated the relationship between host cytokines response and their roles in pathogenesis in chickens infected with HPAIVs.
Project description:The mechanisms responsible for the molecular pathogenesis of the highly pathogenic avian influenza virus (HPAIV) or low pathogenic avian influenza virus (LPAIV) in avian species remain poorly understood. Thus, global immune response of chickens infected with HPAIV H5N1 (A/duck/India/02CA10/2011) and LPAIV H9N2 (A/duck/India/249800/2010) viruses was studied using microarray to identify crucial host genetic components responsive to these infection. HPAIV H5N1 induced excessive mRNA expression of cytokines (IFNA, OASL, MX1, RSAD2, IFITM5, GBP 1, IL1B, IL18, IL22, IL13, IL12B, CCL4, CCL9, CCL10, CX3CL1 etc) in lung tissues. This excessive cytokine response (cytokine storms) may cause tissue damage and high mortality in chickens. In contrast, the expression levels of most of the cytokines remained unchanged in the lungs of LPAIV H9N2 virus infected chickens. This study indicated the relationship between host cytokines response and their roles in pathogenesis in chickens infected with HPAIVs. Agilent Custom Chicken Gene Expression 8X60k (AMADID: G4102A_059389) designed by Genotypic Technology Private Limited , Labeling kit: Agilent Quick-Amp labeling Kit (p/n5190-0442)
Project description:We isolated two highly pathogenic H5N1 avian influenza viruses (AIVs) (CK10 and GS10) with similar genetic background but greatly differ in pathogencity in mice. CK10 is highly pathogenic in mice, whereas GS10 is nonpathogenic. However, the host mechanism of this differecne in pathogenicity is unclear. We used microarray analysis to evaluate the global transcriptional response in the lung of mice infected with CK10 or GS10.
Project description:Viral pathogens are an ongoing threat to public health worldwide. Dissecting their dependence on host biosynthetic pathways could lead to effective antiviral therapies. To define how entero- and flaviviruses redirect host ribosomes to synthesize viral proteins and disable host protein production, we performed proteomic analysis of lysates and isolated polysomes from human Huh7 cells infected with either polio, zika or dengue viruses. We find that infection remodels polysome composition along similar principles, without major changes to core ribosome stoichiometry. These viruses use different strategies to evictfrom polysomes a common set of translation initiation and RNA surveillance factors while recruiting host machineries specifically required for viral biogenesis. We also find that both zika and dengue utilize the collagen prolyl-hydroxylation machinery to mediate co-translational modification of conserved prolines in the viral polyprotein. Our findings show how RNA viruses co-opt polysome modularity and establish a powerful strategy to identify targets for selective antiviral interventions.
Project description:Iron withholding controls infections by limiting the pathogens’ access to iron from the host. Viruses directly utilize intracellular materials, including iron, to complete their life cycles. Emerging evidence suggests the importance of withholding iron in limiting viral infections. However, the mechanisms through which viruses disrupt host iron homeostasis and the impact of intracellular iron on the host’s antiviral defense remain unknown. Here we show that viral infections facilitate the polyubiquitination and degradation of ferroportin (FPN1, the only cellular iron exporter) by upregulating the host E3 ubiquitin ligase DTX3L, leading to an elevation in cellular iron levels. Excessive ferrous suppresses type I IFN responses and autophagy by promoting TBK1 hydroxylation and STING carbonylation in macrophages. FPN1 deficiency suppresses host antiviral defense and facilitates viral replication in vitro and in vivo, while DTX3L deficiency has the opposite effect. These results reveal that viruses hijack host FPN1 to disrupt iron withholding and achieve immune escape, and suggest that iron homeostasis maintained by FPN1 is required for the optimal activation of TBK1- and STING-dependent antiviral responses.
Project description:Certain organs are capable of containing the replication of various types of viruses. In the liver, infection of Hepatitis B virus (HBV), the etiological factor of Hepatitis B and hepatocellular carcinoma (HCC), often remains asymptomatic and leads to a chronic carrier state. Here we investigated how hepatocytes contain HBV replication and promote their own survival by orchestrating a translational defense mechanism via the stress-sensitive SUMO-2/3-specific peptidase SENP3. We found that SENP3 expression level decreased in HBV-infected hepatocytes in various models including HepG2-NTCP cell lines and a humanized mouse model. Downregulation of SENP3 reduced HBV replication and boosted host protein translation. We also discovered that IQGAP2, a Ras GTPase-activating-like protein, is a key substrate for SENP3-mediated de-SUMOylation. Downregulation of SENP3 in HBV infected cells facilitated IQGAP2 SUMOylation and degradation, which leads to suppression of HBV gene expression and restoration of global translation of host genes via modulation of AKT phosphorylation. Thus, The SENP3-IQGAP2 de-SUMOylation axis is a host defense mechanism of hepatocytes that restores host protein translation and suppresses HBV gene expression.