Membrane Retention of West Nile Virus NS5 Depends on NS1 or NS3 for Enzymatic Activity.

West Nile virus (WNV) nonstructural protein 5 (NS5) possesses multiple enzymatic domains essential for viral RNA replication. During infection, NS5 predominantly localizes to unique replication organelles (ROs) at the rough endoplasmic reticulum (RER), known as vesicle packets (VPs) and convoluted membranes (CMs), with a portion of NS5 accumulating in the nucleus. NS5 is a soluble protein that must be in the VP, where its enzymatic activities are required for viral RNA synthesis.

Potential Dual Role of West Nile Virus NS2B in Orchestrating NS3 Enzymatic Activity in Viral Replication.

West Nile virus (WNV) nonstructural protein 3 (NS3) harbors the viral triphosphatase and helicase for viral RNA synthesis and, together with NS2B, constitutes the protease responsible for polyprotein processing. NS3 is a soluble protein, but it is localized to specialized compartments at the rough endoplasmic reticulum (RER), where its enzymatic functions are essential for virus replication. However, the mechanistic details behind the recruitment of NS3 from the cytoplasm to the RER have not yet been fully elucidated.

Selective Reactivity of Anti-Japanese Encephalitis Virus NS4B Antibody Towards Different Flaviviruses.

Studies investigating West Nile virus (WNV) NS4B protein function are hindered by the lack of an antibody recognizing WNV NS4B protein. Few laboratories have produced WNV NS4B antibodies, and none have been shown to work consistently. In this report, we describe a NS4B antibody against Japanese encephalitis virus (JEV) NS4B protein that cross-reacts with the NS4B protein of WNV but not of dengue virus (DENV).

Functional Analysis of West Nile Virus Proteins in Human Cells.

West Nile Virus (WNV) lineage 2 strains have been responsible for large outbreaks of neuroinvasive disease in the United States and Europe between 1999 and 2012. Different strains in this lineage have previously been shown to produce either severe or mild neuroinvasive disease in mice. Phylogenetic and amino acid comparisons between highly or less virulent lineage 2 strains have demonstrated that the nonstructural (NS) gene(s) were most variable.

Induction of endoplasmic reticulum-derived replication-competent membrane structures by West Nile virus non-structural protein 4B.

Replication of flaviviruses (family Flaviviridae) occurs in specialized virus-induced membrane structures (IMS). The cellular composition of these IMS varies for different flaviviruses implying different organelle origins for IMS biogenesis. The role of flavivirus non-structural (NS) proteins for the alteration of IMS remains controversial.

Stimulation of unprimed macrophages with immune complexes triggers a low output of nitric oxide by calcium-dependent neuronal nitric-oxide synthase.

Immune complexes composed of IgG-opsonized pathogens, particles, or proteins are phagocytosed by macrophages through Fcγ receptors (FcγRs). Macrophages primed with IFNγ or other pro-inflammatory mediators respond to FcγR engagement by secreting high levels of cytokines and nitric oxide (NO). We found that unprimed macrophages produced lower levels of NO, which required efficient calcium (Ca(2+)) flux as demonstrated by using macrophages lacking selenoprotein K, which is required for FcγR-induced Ca(2+) flux.

Dengue hemorrhagic fever-associated immunomediators induced via maturation of dengue virus nonstructural 4B protein in monocytes modulate endothelial cell adhesion molecules and human microvascular endothelial cells permeability.

We previously demonstrated that dengue virus (DENV) nonstructural 4B protein (NS4B) induced dengue hemorrhagic fever (DHF)-associated immunomediators in THP-1 monocytes. Moreover, cleavage of NS4AB polyprotein by the NS2B3 protease, significantly increased immunomediator production to levels found after DENV infection. In this report using primary human microvascular endothelial cells (HMVEC) transwell permeability model and HMVEC monolayer, we demonstrate that the immunomediators secreted in the supernatants of DENV-infected monocytes increase HMVEC permeability and expression of ICAM-1, VCAM-1 and E-selectin.

Maturation of dengue virus nonstructural protein 4B in monocytes enhances production of dengue hemorrhagic fever-associated chemokines and cytokines.

High levels of viremia and chemokines and cytokines underlie the progression of severe dengue disease. Dengue virus (DENV) preferentially infects peripheral blood monocytes, which secrete elevated levels of immunomediators in patients with severe disease. Further, DENV nonstructural proteins (NS) are capable of modifying intracellular signaling, including interferon inhibition.

Serotonin receptor 2A blocker (risperidone) has no effect on human polyomavirus JC infection of primary human fetal glial cells.

A recent report demonstrated that JC virus (JCV) employs serotonin receptor 2A (5HT(2A)R) to infect the glial cells. To assess the ability of a potent 5HT(2A)R blocker, risperidone, to inhibit JCV infection, the authors treated primary human fetal glial (PHFG) cells in vitro with risperidone for 24 h and inoculated with JCV(Mad1). There was no significant difference in JCV genome copies or mRNA transcripts and protein expression in treatment-naive and risperidone-treated PHFG cells.

Traditional kava beverage consumption and liver function tests in a predominantly Tongan population in Hawaii.

Purpose: To determine the effects of traditionally prepared kava beverages on the liver function tests of regular kava beverage consumers in a population of Tongan and non-Tongan residents of Hawaii (Oahu).

Methods: The liver function tests of 31 healthy adult kava drinkers were compared against a control group of 31 healthy adult non-kava drinkers. Subjects were recruited from the general population, a kava bar, and Tongan kava drinking circles.

Determination of kavalactones in dried kava (Piper methysticum) powder using near-infrared reflectance spectroscopy and partial least-squares regression.

Kava (Piper methysticum Forst F.), or àwa in the Hawaiian language, has been used for thousands of years by the people of the South Pacific Islands, in particular Fiji, Vanuatu, Tonga, and Samoa, for social and ceremonial occasions. Kava has the unique ability to promote a state of relaxation without the loss of mental alertness.

Regulation of exopolysaccharide synthesis in Rhizobium sp. strain TAL1145 involves an alternative sigma factor gene, rpoH2.

Exopolysaccharide (EPS) produced by Rhizobium sp. strain TAL1145 has been shown to be essential for effective nodulation on Leucaena leucocephala (leucaena). This paper reports the isolation and characterization of an alternative sigma factor gene, rpoH2, involved in the regulation of EPS synthesis in TAL1145.