poxvirus
Virus-Cell InteractionsThe Vaccinia Virus B12 Pseudokinase Represses Viral Replication via Interaction with the Cellular Kinase VRK1 and Activation of the Antiviral Effector BAFViruses from diverse families encode both positive and negative regulators of viral replication. While their functions can sometimes be enigmatic, investigation of virus-encoded, negative regulators of viral replication has revealed fascinating aspects of virology.
Virus-Cell InteractionsThe Molluscum Contagiosum Gene MC021L Partially Compensates for the Loss of Its Vaccinia Virus Homolog, F13LThe vaccinia virus extracellular virion protein F13 is required for the production and release of infectious extracellular virus, which in turn is essential for the subsequent spread and pathogenesis of orthopoxviruses. Molluscum contagiosum virus infects millions of people worldwide each year, but it is unknown whether EV are produced during infection for spread. Molluscum contagiosum virus contains a homolog of F13L termed MC021L. To...
Genetic Diversity and EvolutionInactivation of Genes by Frameshift Mutations Provides Rapid Adaptation of an Attenuated Vaccinia VirusGene inactivation is considered to be an important driver of orthopoxvirus evolution. Whereas cowpox virus contains intact orthologs of genes present in each orthopoxvirus species, numerous genes are inactivated in all other members of the genus. Inactivation of additional genes can occur upon extensive passaging of orthopoxviruses in cell culture leading to attenuation in vivo, a strategy for making vaccines. Whether...
Genetic Diversity and Evolution | SpotlightA Mutualistic Poxvirus Exhibits Convergent Evolution with Other Heritable Viruses in Parasitoid WaspsViruses are generally considered to be disease-causing agents, but several instances of beneficial viral elements have been identified in insects called parasitoid wasps. These virus-derived entities are passed on through wasp generations and enhance the success of the wasps’ parasitic life cycle. Many parasitoid-virus partnerships studied to date exhibit common features among independent cases of this phenomenon, including a mother-to-...
Virus-Cell Interactions | SpotlightVaccinia Virus Glycoproteins A33, A34, and B5 Form a Complex for Efficient Endoplasmic Reticulum to trans-Golgi Network TransportThe secondary intracellular envelopment of poxviruses at the trans-Golgi network to release infectious extracellular virus (EV) is essential for their spread and pathogenesis. Viral glycoproteins A33, A34, and B5 are critical for the efficient production of infectious EV and interactions among these proteins are important for their localization and incorporation into the outer extracellular virion membrane. We have uncovered a...
Pathogenesis and Immunity | SpotlightLoss of Resistance to Mousepox during Chronic Lymphocytic Choriomeningitis Virus Infection Is Associated with Impaired T-Cell Responses and Can Be Rescued by ImmunizationChronic viral infections may result in immunosuppression and enhanced susceptibility to infections with other pathogens. For example, we have recently shown that mice chronically infected with lymphocytic choriomeningitis virus (LCMV) clone 13 (CL13) are highly susceptible to mousepox, a disease that is caused by ectromelia virus and that is the mouse homolog of human smallpox. Here we show chronic CL13 infection severely disrupts the...
Pathogenesis and Immunity | SpotlightChronic Lymphocytic Choriomeningitis Infection Causes Susceptibility to Mousepox and Impairs Natural Killer Cell Maturation and FunctionInfection of adult mice with the clone 13 (CL13) strain of lymphocytic choriomeningitis virus (LCMV) is extensively used as a model of chronic infection. In this paper, we show that mice chronically infected with CL13 succumb to challenge with ectromelia virus (ECTV; the agent of mousepox) and that natural killer (NK) cells in CL13-infected mice are reduced in numbers and have an immature and partially activated phenotype but do respond...
Genome Replication and Regulation of Viral Gene Expression | SpotlightSpecific Anchoring and Local Translation of Poxviral ATI mRNA at Cytoplasmic Inclusion BodiesPoxvirus genome replication, transcription, translation, and virion assembly occur at sites within the cytoplasm known as factories. Some poxviruses sequester infectious virions outside of the factories in inclusion bodies comprised of numerous copies of the 150-kDa ATI protein, which can provide stability and protection in the environment. We provide evidence that ATI mRNA is anchored by nascent peptides and translated at the inclusion...
Cellular Response to InfectionLack of B Lymphocytes Enhances CD8 T Cell-Mediated Resistance against Respiratory Viral Infection but Compromises Memory Cell FormationB cells play critical role in host resistance against many respiratory viral infections. However, the role of B cells beyond antibody-producing cells is less well defined. In this study, we made a surprising observation that mice lacking B cells were more resistant to respiratory infection with vaccinia virus than wild-type mice. This enhanced resistance was mediated by CD8 T cells because when we depleted CD8 T cells in B cell-...
Genetic Diversity and Evolution | SpotlightIsolation and Characterization of Akhmeta Virus from Wild-Caught Rodents (Apodemus spp.) in GeorgiaAkhmeta virus is a unique Orthopoxvirus that was described in 2013 from the country of Georgia. This paper presents the first isolation of this virus from small mammal (Rodentia; Apodemus spp.) samples and the molecular characterization of those isolates. The identification of the virus in small mammals is an essential component to understanding the natural history of this virus and its transmission to human...