The role of the NS1 protein in modulating influenza A virulence and host range was assessed by adapting A/Hong Kong/1/1968 (H3N2) (HK-wt) to increased virulence in the mouse. Sequencing the NS genome segment of mouse-adapted variants revealed 11 mutations in the NS1 gene and 4 in the overlapping NEP gene. Using the HK-wt virus and reverse genetics to incorporate mutant NS gene segments, we demo...

The flavivirus NS1 protein is a highly conserved nonstructural glycoprotein that is capable of eliciting protective immunity. NS1 homodimers are secreted from virus-infected mammalian cells, but the protein is also present at the plasma membrane and in the lumen of intracellular vesicles. Based on these properties, it has been speculated that NS1 may function in virus maturation or release. To ...

BACKGROUND H7N9, emerged as an avian influenza virus outbreak in Eastern China in early 2013, and represented another major threat to global health. Roles of its NS1 protein, an essential viral factor, in regulating apoptosis remain unknown. METHODS Apoptotic effect and features of H7N9/NS1 in the human A549 alveolar basal epithelial cell line were examined by caspase 3/7 activity assay and w...

We analyzed the functions of the influenza B virus nonstructural NS1-B protein, both by utilizing a constructed mutant virus (Delta NS1-B) lacking the NS1 gene and by testing the activities of the protein when expressed in cells. The mutant virus replicated to intermediate levels in 6-day-old embryonated chicken eggs that contain an immature interferon (IFN) system, whereas older eggs did not s...

Timely and accurate dengue diagnosis is important for differential diagnosis and immediate implementation of appropriate disease control measures. In this study, we compared the usefulness and applicability of NS1 RDT (NS1 Ag Strip) and qRT-PCR tests in complementing the IgM ELISA for dengue diagnosis on single serum specimen (n = 375). The NS1 Ag Strip and qRT-PCR showed a fair concordance (κ ...

The nonstructural protein NS1 of the autonomous parvovirus minute virus of mice interferes with cell division and can cause cell death, depending on the cell transformation state. Upon infection, the synthesis of NS1 protein is massively initiated during S phase. In this article, we show that minute virus of mice-infected cells accumulate in this phase. To investigate the link between NS1 accum...

OBJECTIVES Respiratory syncytial virus (RSV) nonstructural protein NS1 (NS1) has been shown to block interferon (IFN)-inducible antiviral signaling. The suppressor of cytokine signaling (SOCS) gene family could utilize a feedback loop to block the activation of the JAK/STAT signaling pathway, further inhibiting the activation of host type I IFN. We evaluated the role of the SOCS1 and SOCS3 gene...

Viruses of the Paramyxoviridae family, such as the respiratory syncytial virus (RSV), suppress cellular innate immunity represented by type I interferon (IFN) for optimal growth in their hosts. The two unique nonstructural (NS) proteins, NS1 and NS2, of RSV suppress IFN synthesis, as well as IFN function, but their exact targets are still uncharacterized. Here, we investigate if either or both ...

The narrow sheath duplicate genes (ns1 and ns2) perform redundant functions during maize leaf development. Plants homozygous for mutations in both ns genes fail to develop wild-type leaf tissue in a lateral domain that includes the leaf margin. Previous studies indicated that the NS gene product(s) functions during recruitment of leaf founder-cells in a lateral, meristematic domain that contrib...

Influenza A virus (IAV) is a major human pathogen with the potential to become pandemic. IAV contains only eight RNA segments; thus, the virus must fully exploit the host cellular machinery to facilitate its own replication. In an effort to comprehensively characterize the host machinery taken over by IAV in mammalian cells, we generated stable A549 cell lines with over-expression of the viral ...