Bats,probably the most abundant,diverse and geographically dispersed vertebrates on earth,have recently been shown to be the reservoir hosts of a number of emerging viruses responsible for severe human and livestock d...Bats,probably the most abundant,diverse and geographically dispersed vertebrates on earth,have recently been shown to be the reservoir hosts of a number of emerging viruses responsible for severe human and livestock disease outbreaks. Flying foxes have been demonstrated to be the natural reservoir for Hendra and Nipah viruses. Evidence supporting the possibility of bats as potential reservoirs for SARS coronavirus(SARS-CoV) and Ebola virus has also been reported. The recent discovery of these viruses and other viruses occurring naturally in the bat population provides a unique insight into a diverse pool of potentially emergent and pathogenic viruses. The factors which influence the ability of zoonotic viruses to effectively cross the species barrier from bats to other animal populations are poorly understood. A brief review is provided here on the recently emerged bat viruses and on current and future strategies for research in this area.展开更多
Programmed cell death （apoptosis） is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent stud...Programmed cell death （apoptosis） is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 （IIV-6） （Iridoviridae, genus Iridovirus）, or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component（s）. Studies with a JNK inhibitor （SP600125） indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana cells. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene （193R） that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus （CpGV）. Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 lap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.展开更多
Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In...Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In this review I provide an overview of the Dicistroviridae and describe progress made toward the understanding and practical application of dicistroviruses, including (i) construction of the first infectious clone of a dicistrovirus, (ii) use of the baculovirus expression system for production of an infectious dicistrovirus, (iii) the use of Drosophila C virus for analysis of host response to virus infection, and (iv) correlation of the presence of Israeli acute paralysis virus with honey bee colony collapse disorder. The potential use of dicistroviruses for insect pest management is also discussed. The structure, mechanism and practical use of the internal ribosome entry site (IRES) elements has recently been reviewed elsewhere.展开更多
Gene silencing (RNA silencing) plays a fundamental role in antiviral defense in plants, fungi and invertebrates. Viruses encode proteins that suppress gene silencing to counter host defense. Viral suppressors of RNA s...Gene silencing (RNA silencing) plays a fundamental role in antiviral defense in plants, fungi and invertebrates. Viruses encode proteins that suppress gene silencing to counter host defense. Viral suppressors of RNA silencing (VSRs) have been identified from almost all plant virus genera and some viruses of insects and mammals. Recent studies have revealed that VSRs counter host defense and interfere with host gene regulation by interacting with RNA or important components of the RNA silencing pathway. Here, we review the current understanding of the complex mechanisms of VSRs that have been revealed by recent studies.展开更多
文摘Bats,probably the most abundant,diverse and geographically dispersed vertebrates on earth,have recently been shown to be the reservoir hosts of a number of emerging viruses responsible for severe human and livestock disease outbreaks. Flying foxes have been demonstrated to be the natural reservoir for Hendra and Nipah viruses. Evidence supporting the possibility of bats as potential reservoirs for SARS coronavirus(SARS-CoV) and Ebola virus has also been reported. The recent discovery of these viruses and other viruses occurring naturally in the bat population provides a unique insight into a diverse pool of potentially emergent and pathogenic viruses. The factors which influence the ability of zoonotic viruses to effectively cross the species barrier from bats to other animal populations are poorly understood. A brief review is provided here on the recently emerged bat viruses and on current and future strategies for research in this area.
基金SLB was supported in part by Research Enhancement FundsResearch Development Funds from the Office of the Vice-President for Research, Texas Tech University and the Texas Higher Education Coordin-ating Boardprovided by the Depar-tment of Biological Sciences at Texas Tech University
文摘Programmed cell death （apoptosis） is a key host response to virus infection. Viruses that can modulate host apoptotic responses are likely to gain important opportunities for transmission. Here we review recent studies that demonstrate that particles of Invertebrate iridescent virus 6 （IIV-6） （Iridoviridae, genus Iridovirus）, or an IIV-6 virion protein extract, are capable of inducing apoptosis in lepidopteran and coleopteran cells, at concentrations 1000-fold lower than that required to shut-off host macromolecular synthesis. Induction of apoptosis depends on endocytosis of one or more heat-sensitive virion component（s）. Studies with a JNK inhibitor （SP600125） indicated that the JNK signaling pathway is significantly involved in apoptosis in IIV-6 infections of Choristoneurafumiferana cells. The genome of IIV-6 codes for an inhibitor of apoptosis iap gene （193R） that encodes a protein of 208 aa with 15% identity and 28% similarity in its amino acid sequence to IAP-3 from Cydia pomonella ganulovirus （CpGV）. Transcription of IIV-6 iap did not require prior DNA or protein synthesis, indicating that it is an immediate-early class gene. Transient expression and gene knockdown studies have confirmed the functional nature of the IIV-6 lap gene. We present a tentative model for IIV-6 induction and inhibition of apoptosis in insect cells and discuss the potential applications of these findings in insect pest control.
基金This journal paper of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa,Project No. 6673, was supported by the Iowa State University Plant Sciences Institute, and the Consortium for Plant Biotechnology Research
文摘Dicistroviruses comprise a newly characterized and rapidly expanding family of small RNA viruses of invertebrates. Several features of this virus group have attracted considerable research interest in recent years. In this review I provide an overview of the Dicistroviridae and describe progress made toward the understanding and practical application of dicistroviruses, including (i) construction of the first infectious clone of a dicistrovirus, (ii) use of the baculovirus expression system for production of an infectious dicistrovirus, (iii) the use of Drosophila C virus for analysis of host response to virus infection, and (iv) correlation of the presence of Israeli acute paralysis virus with honey bee colony collapse disorder. The potential use of dicistroviruses for insect pest management is also discussed. The structure, mechanism and practical use of the internal ribosome entry site (IRES) elements has recently been reviewed elsewhere.
基金supported by the National Basic Research Program of China (Grant No. 2012CB114004)the National Natural Science Foundation of China (Grant Nos. 31030005 and 30910103904)
文摘Gene silencing (RNA silencing) plays a fundamental role in antiviral defense in plants, fungi and invertebrates. Viruses encode proteins that suppress gene silencing to counter host defense. Viral suppressors of RNA silencing (VSRs) have been identified from almost all plant virus genera and some viruses of insects and mammals. Recent studies have revealed that VSRs counter host defense and interfere with host gene regulation by interacting with RNA or important components of the RNA silencing pathway. Here, we review the current understanding of the complex mechanisms of VSRs that have been revealed by recent studies.
