IFITM3 restricts the morbidity and mortality associated with influenza

SARS-CoV-2: Understanding the Transcriptional Regulation of ACE2 and TMPRSS2 and the Role of Single Nucleotide Polymorphism (SNP) at Codon 72 of p53 in the Innate Immune Response against Virus Infection

Human ACE2 and the serine protease TMPRSS2 of novel SARS-CoV-2 are primary entry receptors in host cells. Expression of these genes at the transcriptional level has not been much discussed in detail. The ISRE elements of the ACE2 promoter are a binding site for the ISGF3 complex of the JAK/STAT signaling pathway. TMPRSS2, including IFNβ, STAT1, and STAT2, has the PARP1 binding site near to TSS either up or downstream promoter region. It is well documented that PARP1 regulates gene expression at the transcription level. Therefore, to curb virus infection, both promoting type I IFN signaling to boost innate immunity and prevention of virus entry by inhibiting PARP1, ACE2 or TMPRSS2 are safe options. Most importantly, our aim is to attract the attention of the global scientific community towards the codon 72 Single Nucleotide Polymorphism (SNP) of p53 and its underneath role in the innate immune response against SARS-CoV-2. Here, we discuss codon 72 SNP of human p53's role in the different innate immune response to restrict virus-mediated mortality rate only in specific parts of the world. In addition, we discuss potential targets and emerging therapies using bioengineered bacteriophage, anti-sense, or CRISPR strategies.

Explore the potential effect of natural herbals to resist Newcastle Disease Virus

In this study, we examined the dose-dependent effects of the formula on Newcastle disease virus (NDV). In in-vitro test, the formula within safety concentration scope and NDV were added into cultured chick embryo fibroblast in 3 modes, and the cellular A570 values were determined by MTT (3-(4, 5-dimethyithiazol-2-yl)-2, 5-diphenyltetrazolium bromide) method. In in-vivo test, we examined the expression of interferon-induced transmembrane protein 3 (IFITM3) and Interferons (IFNs) in NDV-infected chickens. The results showed that the highest virus inhibitory rates of the formula at optimal concentration group were the highest (15.625 mg/mL) in post-adding and simultaneous-adding drug and virus modes, whereas medium concentration (7.813 mg/mL) showed the highest virus inhibitory rates in pre-adding drug mode. In vivo, the formula significantly upregulated the expression of IFITM3 in NDV-infected chickens at 3-D post-infection. However, the levels of IFNs were significantly downregulated. On days 5 and 7 post-infection, the levels of IFNs quickly upregulated. Moreover, the formula can significantly upregulate the antibody to resist the NDV compared with model control group on days 5 and 7 post-infection. In animals treated with the formula, the survival rate was nearly 37% higher at 7 d post-infection. We also found that the formula had a significantly stronger effect than a single herb on upregulating the expression of IFITM3. It confirmed that the formula could significantly inhibit the infectivity of NDV to chick embryo fibroblast. Also, the formula could significantly upregulated IFITM3 expression and inhibited virus replication in NDV-infected chickens. During the early stage of infection, IFNs were consumed to stimulate IFITM3 to inhibit virus replication, whereas during later stages of the infection, the formula upregulated the levels of IFNs and their antibodies to maintain a high level of immunity.

Reduction of Influenza Virus Envelope's Fusogenicity by Viral Fusion Inhibitors

During cell entry of an enveloped virus, the viral membrane must be fused with the cellular membrane. The virus envelope has a unique structure consisting of viral proteins and a virus-specific lipid composition, whereas the host membrane has its own structure with host membrane proteins. Compound 136 was previously found to bind in close proximity to the viral envelope and inhibit influenza virus entry. We showed here that the 136-treated influenza virus still caused hemolysis. When liposomes were used as the target membrane for 136-treated viruses, aberrant fusion occurred; few liposomes fused per virion, and glycoproteins were not distributed evenly across fusion complexes. Additionally, large fusion aggregates did not form, and in some instances, neck-like structures were found. Based on previous results and hemolysis, fusion inhibition by 136 occurs post-scission but prior to lipid mixing.

Characterization in vitro and in vivo of a pandemic H1N1 influenza virus from a fatal case

Pandemic 2009 H1N1 (pH1N1) influenza viruses caused mild symptoms in most infected patients. However, a greater rate of severe disease was observed in healthy young adults and children without co-morbid conditions. Here we tested whether influenza strains displaying differential virulence could be present among circulating pH1N1 viruses. The biological properties and the genotype of viruses isolated from a patient showing mild disease (M) or from a fatal case (F), both without known co-morbid conditions were compared in vitro and in vivo. The F virus presented faster growth kinetics and stronger induction of cytokines than M virus in human alveolar lung epithelial cells. In the murine model in vivo, the F virus showed a stronger morbidity and mortality than M virus. Remarkably, a higher proportion of mice presenting infectious virus in the hearts, was found in F virus-infected animals. Altogether, the data indicate that strains of pH1N1 virus with enhanced pathogenicity circulated during the 2009 pandemic. In addition, examination of chemokine receptor 5 (CCR5) genotype, recently reported as involved in severe influenza virus disease, revealed that the F virus-infected patient was homozygous for the deleted form of CCR5 receptor (CCR5Δ32).