Background: Cytosolic double-stranded RNA (dsRNA) is an important ‘molecular signature’ for the detection of intracellular viral infections. Although intracellular dsRNA is a known potent inducer of apoptosis, the optimal time and dose for the onset of dsRNA-mediated apoptosis have not been studied in detail. Objective: To perform an accurate temporal assessment of the cell death responses in d...

Invertebrate RNA viruses are targets of the host RNA interference (RNAi) pathway, which limits virus infection by degrading viral RNA substrates. Several insect RNA viruses encode suppressor proteins to counteract this antiviral response. We recently demonstrated that the dsDNA virus Invertebrate iridescent virus 6 (IIV-6) induces an RNAi response in Drosophila. Here, we show that RNAi is suppr...

The electrophoretic patterns of dsRNA species isolated from cucumber plants infected with cucumber necrosis virus (CNV) and from Nicotiana clevelandii plants infected with tomato bushy stunt virus (TBSV) were almost identical and differed greatly from the electrophoretic patterns of dsRNA species isolated from tobacco plants infected with tobacco necrosis virus (TNV). Hybridization with cloned ...

A population of oligonucleotides co-purified with the dsRNA genomic segments of the killer virus of Saccharomyces cerevisiae during electrophoresis through agarose gels. These smaller RNA molecules must be separated from the viral genome in order to determine the structure of the dsRNA molecules. Sequence analysis of these isolated oligonucleotides showed that the population contained tRNA-like...

Virus-derived double-stranded RNAs (dsRNAs) are sensed in the cytosol by retinoic acid-inducible gene (RIG)-I-like receptors (RLRs). These induce the expression of type I IFN and proinflammatory cytokines through signaling pathways mediated by the mitochondrial antiviral signaling (MAVS) protein. TNF receptor-associated factor (TRAF) family proteins are reported to facilitate the RLR-dependent ...

Dicer enzymes process virus-specific double-stranded RNA (dsRNA) into small interfering RNAs (siRNAs) to initiate specific antiviral defense by related RNA interference (RNAi) pathways in plants, insects, nematodes, and mammals. Antiviral RNAi in Caenorhabditis elegans requires Dicer-related helicase 1 (DRH-1), not found in plants and insects but highly homologous to mammalian retinoic acid-ind...

In plants, fungi, and invertebrates, antiviral RNAi is activated by processing viral doublestranded RNA (dsRNA) replication intermediates into virus-derived small interfering RNAs (vsiRNAs). Typically of a discrete length of ~22 nt, vsiRNAs form perfect duplexes, with 2 nt 3′ overhangs diagnostic of the Dicer-like RNase III activities that generate them across kingdoms. vsiRNAs are loaded into ...

RNA interference (RNAi) is a crucial antiviral defense mechanism in insects, including the major mosquito species that transmit important human viruses. To counteract the potent antiviral RNAi pathway, insect viruses encode RNAi suppressors. However, whether mosquito-specific viruses suppress RNAi remains unclear. We therefore set out to study RNAi suppression by Culex Y virus (CYV), a mosquito...

Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine leads to a serious disease characterized by delayed and defective adaptive immune response. It is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. In the study presented here we tested this hypothesis and identified several non-structural proteins (nsps) with innate i...

Porcine reproductive and respiratory syndrome virus (PRRSV) infection of swine leads to a serious disease characterized by a delayed and defective adaptive immune response. It is hypothesized that a suboptimal innate immune response is responsible for the disease pathogenesis. In the study presented here we tested this hypothesis and identified several nonstructural proteins (NSPs) with innate ...