Through gain-of-function and loss-of-function analyses, a critical determinant within the neuraminidase ectodomain was identified that contributes to VLP formation but is not sufficient to accomplish release of plasmid-derived VLPs. This sequence lies on the plasma

membrane-proximal side of the neuraminidase globular head. Most importantly, we demonstrate that the antiviral restriction factor tetherin plays a role in determining the strain-specific limitations of release competency. If tetherin is counteracted by small interfering RNA knockdown or expression of the HIV anti-tetherin factor vpu, budding and release capability is bestowed upon an otherwise budding-deficient neuraminidase. These data suggest that budding-competent neuraminidase proteins possess an as-yet-unidentified means of counteracting the antiviral restriction factor tetherin and identify Repotrectinib manufacturer a novel way in which the influenza virus neuraminidase can contribute to virus release.”
“Identification of virulence determinants of viruses is of critical importance in virology. In search of such determinants, virologists traditionally utilize

comparative genomics between a virulent and an avirulent virus strain and construct chimeras to map their locations. Subsequent comparison reveals sequence differences, and through analyses of site-directed mutants, key residues are identified. In the absence of a naturally occurring virulent strain, an avirulent strain can be functionally Glutathione peroxidase converted to a virulent variant via an experimental evolutionary

Saracatinib supplier approach. However, the concern remains whether experimentally evolved virulence determinants mimic those that have evolved naturally. To provide a direct comparison, we exploited a plant RNA virus, soybean mosaic virus (SMV), and its natural host, soybean. Through a serial in vivo passage experiment, the molecularly cloned genome of an avirulent SMV strain was converted to virulent variants on functionally immune soybean genotypes harboring resistance factor(s) from the complex Rsv1 locus. Several of the experimentally evolved virulence determinants were identical to those discovered through a comparative genomic approach with a naturally evolved virulent strain. Thus, our observations validate an experimental evolutionary approach to identify relevant virulence determinants of an RNA virus.”
“Central nervous system (CNS) infections and autoimmune inflammatory disorders are often associated with retention of antibody-secreting cells (ASC). Although beneficial or detrimental contributions of ASC to CNS diseases remain to be defined, virus-specific ASC are crucial in controlling persistent CNS infection following coronavirus-induced encephalomyelitis. This report characterizes expression kinetics of factors associated with ASC homing, differentiation, and survival in the spinal cord, the prominent site of coronavirus persistence.