Parvovirus B19 has been implicated in some cases of acute fulminant non-A, non-B, non-C, non-G liver failure. Our laboratory previously demonstrated that B19 infection of hepatocytes induces apoptosis and that the B19 viral nonstructural protein, NS1, may play a critical role. To study the involvement of NS1 in apoptosis of liver cells, we generated a fusion protein of NS1 with enhanced green f...

BACKGROUND Infection with dengue virus (DENV) may cause life-threatening disease with thrombocytopenia and vascular leakage which are related to dysfunction of platelets and endothelial cells. We previously showed that antibodies (Abs) against DENV nonstructural protein 1 (NS1) cross-react with human platelets and endothelial cells, leading to functional disturbances. Based on sequence homology...

We demonstrate the presence of nonstructural protein 1 (NS1)-specific antibodies in a significant proportion of convalescent-phase human serum samples obtained from a cohort in an area where Japanese encephalitis virus (JEV) is endemic. Sera containing antibodies to NS1 but not those with antibodies to other JEV proteins, such as envelope, brought about complement-mediated lysis of JEV-infected...

The nonstructural protein 1 (NS1) of the influenza A virus (IAV) is a multifunctional protein that counteracts host cell antiviral responses and inhibits host cell pre-mRNA processing. NS1 contains two nuclear localization signals that facilitate NS1 shuttling between cytoplasm and nucleus. In this study, we initially observed the novel mitochondria localization of NS1 in a subset of transfecte...

Background Dengue virus nonstructural protein 1 (NS1) is a highly conserved glycoprotein involved in the production of infectious virus and the pathogenesis of dengue disease [1]. Serum or plasma DENV NS1 level has been found to correlate with viremia titer and disease severity. It can be found in the peripheral blood circulation for up to 9 days from illness onset, but can persist for up to 18...

Influenza A viruses (IAVs) are common pathogens of birds that occasionally establish endemic infections in mammals. The processes and mechanisms that result in IAV mammalian adaptation are poorly understood. The viral nonstructural 1 (NS1) protein counteracts the interferon (IFN) response, a central component of the host species barrier. We characterized the NS1 proteins of equine influenza vir...

Human respiratory syncytial virus (RSV), a major cause of severe respiratory diseases, efficiently suppresses cellular innate immunity, represented by type I interferon (IFN), using its two unique nonstructural proteins, NS1 and NS2. In a search for their mechanism, NS1 was previously shown to decrease levels of TRAF3 and IKKε, whereas NS2 interacted with RIG-I and decreased TRAF3 and STAT2. He...

Persistent infection with Japanese encephalitis virus (JEV) was established in murine neuroblastoma N18 cells, and the persistency has been maintained in cell culture for over 6 months. From the persistently infected cells, a clone named C2-2 was selected and expanded to form a stable cell line. The vast majority of C2-2 cells showed viral protein staining by immunofluorescence and continuously...

Detection of nonstructural protein (NS1) is an important diagnostic marker during acute phase of dengue infection. Not only for diagnostic purpose, the protein had important role in vaccine design as well, as a candidate for studying virus assembly and maturation. Various researchers employed different expression systems and strategies for recombinant NS1 protein production. Attempts to express...

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...