The Experts below are selected from a list of 33 Experts worldwide ranked by ideXlab platform
Sarah A. Connolly - One of the best experts on this subject based on the ideXlab platform.
-
A Functional Interaction between Herpes Simplex Virus 1 Glycoprotein gH/gL Domains I and II and gD Is Defined by Using AlphaHerpesvirus gH and gL Chimeras
Journal of virology, 2015Co-Authors: Qing Fan, Richard Longnecker, Sarah A. ConnollyAbstract:ABSTRACT Whereas most viruses require only a single protein to bind to and fuse with cells, Herpesviruses use multiple glycoproteins to mediate virus entry, and thus communication among these proteins is required. For most alphaHerpesviruses, the minimal set of viral proteins required for fusion with the host cell includes glycoproteins gD, gB, and a gH/gL heterodimer. In the current model of entry, gD binds to a cellular receptor and transmits a signal to gH/gL. This signal then triggers gB, the conserved fusion protein, to insert into the target membrane and refold to merge the viral and cellular membranes. We previously demonstrated that gB homologs from two alphaHerpesviruses, herpes simplex virus 1 (HSV-1) and Saimiriine Herpesvirus 1 (SaHV-1), were interchangeable. In contrast, neither gD nor gH/gL functioned with heterotypic entry glycoproteins, indicating that gD and gH/gL exhibit an essential type-specific functional interaction. To map this homotypic interaction site on gH/gL, we generated HSV-1/SaHV-1 gH and gL chimeras. The functional interaction with HSV-1 gD mapped to the N-terminal domains I and II of the HSV-1 gH ectodomain. The core of HSV-1 gL that interacts with gH also was required for functional homotypic interaction. The N-terminal gH/gL domains I and II are the least conserved and may have evolved to support species-specific glycoprotein interactions. IMPORTANCE The first step of the Herpesvirus life cycle is entry into a host cell. A coordinated interaction among multiple viral glycoproteins is required to mediate fusion of the viral envelope with the cell membrane. The details of how these glycoproteins interact to trigger fusion are unclear. By swapping the entry glycoproteins of two alphaHerpesviruses (HSV-1 and SaHV-1), we previously demonstrated a functional homotypic interaction between gD and gH/gL. To define the gH and gL requirements for homotypic interaction, we evaluated the function of a panel of HSV-1/SaHV-1 gH and gL chimeras. We demonstrate that domains I and II of HSV-1 gH are sufficient to promote a functional, albeit reduced, interaction with HSV-1 gD. These findings contribute to our model of how the entry glycoproteins cooperate to mediate Herpesvirus entry into the cell.
-
Substitution of herpes simplex virus 1 entry glycoproteins with those of Saimiriine Herpesvirus 1 reveals a gD-gH/gL functional interaction and a region within the gD profusion domain that is critical for fusion
Journal of virology, 2014Co-Authors: Qing Fan, Richard A Longnecker, Sarah A. ConnollyAbstract:ABSTRACT To gain insight into the mechanism of Herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the Saimiriine Herpesvirus 1 (SaHV-1) genome, a primate member of the alphaHerpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaHerpesvirus entry receptors nectin-1 and CD155 but not with Herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILRα). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers from HSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interaction between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. To map the site of this homotypic interaction, we created a series of gD chimeras, focusing on the “profusion domain” (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD. IMPORTANCE The Herpesvirus entry machinery requires the concerted action of at least four glycoproteins; however, details of the interactions among these glycoproteins are not well understood. Like HSV-1, SaHV-1 belongs to the alphaHerpesvirus subfamily. Using cell-cell fusion experiments, we found that SaHV-1 uses the entry receptors nectin-1 and CD155 but not HVEM or PILRα. By swapping the entry glycoproteins between HSV-1 and SaHV-1, we revealed a functional interaction between gD and gH/gL. To examine the homotypic interaction site on gD, we evaluated the function of a panel of HSV-1/SaHV-1 gD chimeras and identified a small region in the SaHV-1 gD profusion domain that is critical for SaHV-1 fusion. This study contributes to our understanding of the molecular mechanisms of Herpesvirus entry and membrane fusion.
Qing Fan - One of the best experts on this subject based on the ideXlab platform.
-
Those of Saimiriine Herpesvirus 1 Reveals a gD-gH/gL Functional Interaction and a Region within the gD Profusion Domain That Is Critical for Fusion
2016Co-Authors: Qing Fan, Richard A Longnecker, Sarah A A. ConnollybAbstract:To gain insight into the mechanism of Herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the Saimiriine Herpesvirus 1 (SaHV-1) genome, a primate member of the alphaHerpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaHerpesvirus entry receptors nectin-1 and CD155 but not with Herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILR). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers fromHSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interac-tion between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. Tomap the site of this homotypic interac-tion, we created a series of gD chimeras, focusing on the “profusion domain ” (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD. IMPORTANC
-
A Functional Interaction between Herpes Simplex Virus 1 Glycoprotein gH/gL Domains I and II and gD Is Defined by Using AlphaHerpesvirus gH and gL Chimeras
Journal of virology, 2015Co-Authors: Qing Fan, Richard Longnecker, Sarah A. ConnollyAbstract:ABSTRACT Whereas most viruses require only a single protein to bind to and fuse with cells, Herpesviruses use multiple glycoproteins to mediate virus entry, and thus communication among these proteins is required. For most alphaHerpesviruses, the minimal set of viral proteins required for fusion with the host cell includes glycoproteins gD, gB, and a gH/gL heterodimer. In the current model of entry, gD binds to a cellular receptor and transmits a signal to gH/gL. This signal then triggers gB, the conserved fusion protein, to insert into the target membrane and refold to merge the viral and cellular membranes. We previously demonstrated that gB homologs from two alphaHerpesviruses, herpes simplex virus 1 (HSV-1) and Saimiriine Herpesvirus 1 (SaHV-1), were interchangeable. In contrast, neither gD nor gH/gL functioned with heterotypic entry glycoproteins, indicating that gD and gH/gL exhibit an essential type-specific functional interaction. To map this homotypic interaction site on gH/gL, we generated HSV-1/SaHV-1 gH and gL chimeras. The functional interaction with HSV-1 gD mapped to the N-terminal domains I and II of the HSV-1 gH ectodomain. The core of HSV-1 gL that interacts with gH also was required for functional homotypic interaction. The N-terminal gH/gL domains I and II are the least conserved and may have evolved to support species-specific glycoprotein interactions. IMPORTANCE The first step of the Herpesvirus life cycle is entry into a host cell. A coordinated interaction among multiple viral glycoproteins is required to mediate fusion of the viral envelope with the cell membrane. The details of how these glycoproteins interact to trigger fusion are unclear. By swapping the entry glycoproteins of two alphaHerpesviruses (HSV-1 and SaHV-1), we previously demonstrated a functional homotypic interaction between gD and gH/gL. To define the gH and gL requirements for homotypic interaction, we evaluated the function of a panel of HSV-1/SaHV-1 gH and gL chimeras. We demonstrate that domains I and II of HSV-1 gH are sufficient to promote a functional, albeit reduced, interaction with HSV-1 gD. These findings contribute to our model of how the entry glycoproteins cooperate to mediate Herpesvirus entry into the cell.
-
Substitution of herpes simplex virus 1 entry glycoproteins with those of Saimiriine Herpesvirus 1 reveals a gD-gH/gL functional interaction and a region within the gD profusion domain that is critical for fusion
Journal of virology, 2014Co-Authors: Qing Fan, Richard A Longnecker, Sarah A. ConnollyAbstract:ABSTRACT To gain insight into the mechanism of Herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the Saimiriine Herpesvirus 1 (SaHV-1) genome, a primate member of the alphaHerpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaHerpesvirus entry receptors nectin-1 and CD155 but not with Herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILRα). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers from HSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interaction between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. To map the site of this homotypic interaction, we created a series of gD chimeras, focusing on the “profusion domain” (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD. IMPORTANCE The Herpesvirus entry machinery requires the concerted action of at least four glycoproteins; however, details of the interactions among these glycoproteins are not well understood. Like HSV-1, SaHV-1 belongs to the alphaHerpesvirus subfamily. Using cell-cell fusion experiments, we found that SaHV-1 uses the entry receptors nectin-1 and CD155 but not HVEM or PILRα. By swapping the entry glycoproteins between HSV-1 and SaHV-1, we revealed a functional interaction between gD and gH/gL. To examine the homotypic interaction site on gD, we evaluated the function of a panel of HSV-1/SaHV-1 gD chimeras and identified a small region in the SaHV-1 gD profusion domain that is critical for SaHV-1 fusion. This study contributes to our understanding of the molecular mechanisms of Herpesvirus entry and membrane fusion.
Richard A Longnecker - One of the best experts on this subject based on the ideXlab platform.
-
Those of Saimiriine Herpesvirus 1 Reveals a gD-gH/gL Functional Interaction and a Region within the gD Profusion Domain That Is Critical for Fusion
2016Co-Authors: Qing Fan, Richard A Longnecker, Sarah A A. ConnollybAbstract:To gain insight into the mechanism of Herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the Saimiriine Herpesvirus 1 (SaHV-1) genome, a primate member of the alphaHerpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaHerpesvirus entry receptors nectin-1 and CD155 but not with Herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILR). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers fromHSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interac-tion between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. Tomap the site of this homotypic interac-tion, we created a series of gD chimeras, focusing on the “profusion domain ” (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD. IMPORTANC
-
Substitution of herpes simplex virus 1 entry glycoproteins with those of Saimiriine Herpesvirus 1 reveals a gD-gH/gL functional interaction and a region within the gD profusion domain that is critical for fusion
Journal of virology, 2014Co-Authors: Qing Fan, Richard A Longnecker, Sarah A. ConnollyAbstract:ABSTRACT To gain insight into the mechanism of Herpesvirus entry into cells, the four glycoproteins that are necessary for herpes simplex virus (HSV) fusion were cloned from the Saimiriine Herpesvirus 1 (SaHV-1) genome, a primate member of the alphaHerpesvirus family. Cell-cell fusion assays indicate that SaHV-1 entry glycoproteins function with the previously identified alphaHerpesvirus entry receptors nectin-1 and CD155 but not with Herpesvirus entry mediator (HVEM) or paired immunoglobulin-like type 2 receptor alpha (PILRα). Replacement of HSV-1 gD with the SaHV-1 gD homolog resulted in a complete loss of fusion function when coexpressed with HSV-1 gB and gH/gL. HSV-1 gD was also unable to substitute for SaHV-1 gD when coexpressed with SaHV-1 gB and gH/gL. Similarly, the gH/gL heterodimers from HSV-1 and SaHV-1 were not interchangeable. In contrast, both the HSV-1 and SaHV-1 gB homologs retained function in a heterotypic context. These results suggest that an essential interaction between homotypic gD and gH/gL occurs during both HSV-1 and SaHV-1 entry. To map the site of this homotypic interaction, we created a series of gD chimeras, focusing on the “profusion domain” (PFD) that consists of HSV-1 gD residues 261 to 305 or SaHV-1 gD residues 264 to 307. We identified a seven-amino-acid stretch (264 RTLPPPK 270) at the N terminus of the SaHV-1 gD PFD that contributes to homotypic fusion. Finally, we found that the gD receptor-binding region and PFD cannot function independently but that both can inhibit the function of wild-type gD. IMPORTANCE The Herpesvirus entry machinery requires the concerted action of at least four glycoproteins; however, details of the interactions among these glycoproteins are not well understood. Like HSV-1, SaHV-1 belongs to the alphaHerpesvirus subfamily. Using cell-cell fusion experiments, we found that SaHV-1 uses the entry receptors nectin-1 and CD155 but not HVEM or PILRα. By swapping the entry glycoproteins between HSV-1 and SaHV-1, we revealed a functional interaction between gD and gH/gL. To examine the homotypic interaction site on gD, we evaluated the function of a panel of HSV-1/SaHV-1 gD chimeras and identified a small region in the SaHV-1 gD profusion domain that is critical for SaHV-1 fusion. This study contributes to our understanding of the molecular mechanisms of Herpesvirus entry and membrane fusion.
Richard Longnecker - One of the best experts on this subject based on the ideXlab platform.
-
A Functional Interaction between Herpes Simplex Virus 1 Glycoprotein gH/gL Domains I and II and gD Is Defined by Using AlphaHerpesvirus gH and gL Chimeras
Journal of virology, 2015Co-Authors: Qing Fan, Richard Longnecker, Sarah A. ConnollyAbstract:ABSTRACT Whereas most viruses require only a single protein to bind to and fuse with cells, Herpesviruses use multiple glycoproteins to mediate virus entry, and thus communication among these proteins is required. For most alphaHerpesviruses, the minimal set of viral proteins required for fusion with the host cell includes glycoproteins gD, gB, and a gH/gL heterodimer. In the current model of entry, gD binds to a cellular receptor and transmits a signal to gH/gL. This signal then triggers gB, the conserved fusion protein, to insert into the target membrane and refold to merge the viral and cellular membranes. We previously demonstrated that gB homologs from two alphaHerpesviruses, herpes simplex virus 1 (HSV-1) and Saimiriine Herpesvirus 1 (SaHV-1), were interchangeable. In contrast, neither gD nor gH/gL functioned with heterotypic entry glycoproteins, indicating that gD and gH/gL exhibit an essential type-specific functional interaction. To map this homotypic interaction site on gH/gL, we generated HSV-1/SaHV-1 gH and gL chimeras. The functional interaction with HSV-1 gD mapped to the N-terminal domains I and II of the HSV-1 gH ectodomain. The core of HSV-1 gL that interacts with gH also was required for functional homotypic interaction. The N-terminal gH/gL domains I and II are the least conserved and may have evolved to support species-specific glycoprotein interactions. IMPORTANCE The first step of the Herpesvirus life cycle is entry into a host cell. A coordinated interaction among multiple viral glycoproteins is required to mediate fusion of the viral envelope with the cell membrane. The details of how these glycoproteins interact to trigger fusion are unclear. By swapping the entry glycoproteins of two alphaHerpesviruses (HSV-1 and SaHV-1), we previously demonstrated a functional homotypic interaction between gD and gH/gL. To define the gH and gL requirements for homotypic interaction, we evaluated the function of a panel of HSV-1/SaHV-1 gH and gL chimeras. We demonstrate that domains I and II of HSV-1 gH are sufficient to promote a functional, albeit reduced, interaction with HSV-1 gD. These findings contribute to our model of how the entry glycoproteins cooperate to mediate Herpesvirus entry into the cell.
R. Eberle - One of the best experts on this subject based on the ideXlab platform.
-
temporal progression of viral replication and gross and histological lesions in balb c mice inoculated epidermally with Saimiriine Herpesvirus 1 sahv 1
Journal of Comparative Pathology, 2005Co-Authors: Melanie A Breshears, R. Eberle, Jerry W RitcheyAbstract:Saimiriine Herpesvirus 1 (SaHV-1), an alphaHerpesvirus enzootic in squirrel monkeys, is genetically related to monkey B virus and human herpes simplex virus (HSV). To study the temporal progression of viral spread and associated lesions, Balb/c mice were inoculated epidermally by scarification with a green fluorescent protein (GFP)-expressing recombinant strain of SaHV-1 and killed sequentially. Pinpoint ulcerative lesions in the inoculated epidermis progressed over a few days to unilateral or bilateral hindlimb paresis or paralysis, urinary and faecal incontinence, abdominal distension, hunched posture and eventual depression warranting euthanasia. Viral replication was present within epidermal keratinocytes, neurons of the dorsal root ganglia and thoracolumbar spinal cord, regional autonomic ganglia, lower urinary tract epithelium and colonic myenteric plexuses, as indicated by histological lesions and GFP expression. Almost all mice inoculated with 10(5) or 10(6) plaque-forming units (PFU) of SaHV-1 developed rapidly progressive disease. Two of eight mice given 10(4)PFU developed disease, but no mice receiving less than 10(4)PFU gave evidence of infection. Mice that showed no clinical signs also failed to develop an antiviral IgG response, indicating absence of active viral infection. For SaHV-1 inoculated epidermally, the ID(50), CNSD(50) and LD(50) values were identical (10(4.38)), indicating that successful infection by this route invariably resulted in lethal CNS (central nervous system) disease. Consistently severe disease in all infected animals, with regionally extensive distribution of viral replication, constituted a marked difference from the disease produced by intramuscular inoculation.
-
Temporal progression of viral replication and gross and histological lesions in Balb/c mice inoculated epidermally with Saimiriine Herpesvirus 1 (SaHV-1).
Journal of comparative pathology, 2005Co-Authors: M. A. Breshears, R. Eberle, J. W. RitcheyAbstract:Saimiriine Herpesvirus 1 (SaHV-1), an alphaHerpesvirus enzootic in squirrel monkeys, is genetically related to monkey B virus and human herpes simplex virus (HSV). To study the temporal progression of viral spread and associated lesions, Balb/c mice were inoculated epidermally by scarification with a green fluorescent protein (GFP)-expressing recombinant strain of SaHV-1 and killed sequentially. Pinpoint ulcerative lesions in the inoculated epidermis progressed over a few days to unilateral or bilateral hindlimb paresis or paralysis, urinary and faecal incontinence, abdominal distension, hunched posture and eventual depression warranting euthanasia. Viral replication was present within epidermal keratinocytes, neurons of the dorsal root ganglia and thoracolumbar spinal cord, regional autonomic ganglia, lower urinary tract epithelium and colonic myenteric plexuses, as indicated by histological lesions and GFP expression. Almost all mice inoculated with 10(5) or 10(6) plaque-forming units (PFU) of SaHV-1 developed rapidly progressive disease. Two of eight mice given 10(4)PFU developed disease, but no mice receiving less than 10(4)PFU gave evidence of infection. Mice that showed no clinical signs also failed to develop an antiviral IgG response, indicating absence of active viral infection. For SaHV-1 inoculated epidermally, the ID(50), CNSD(50) and LD(50) values were identical (10(4.38)), indicating that successful infection by this route invariably resulted in lethal CNS (central nervous system) disease. Consistently severe disease in all infected animals, with regionally extensive distribution of viral replication, constituted a marked difference from the disease produced by intramuscular inoculation.
-
Construction and in vivo detection of an enhanced green fluorescent protein-expressing strain of Saimiriine Herpesvirus 1 (SaHV-1)
Archives of Virology, 2003Co-Authors: M. A. Breshears, D. H. Black, J. W. Ritchey, R. EberleAbstract:Saimiriine Herpesvirus 1 (SaHV-1) is an α-Herpesvirus of squirrel monkeys used in mice to study neural pathogenesis of Herpesviruses. To trace dissemination of virus from a peripheral site of inoculation to the central nervous system tissues, a recombinant strain of SaHV-1 expressing enhanced green fluorescent protein (GFP) was constructed by site-specific insertion of a GFP expression cassette into a transcriptionally null point in the SaHV-1 genome. PCR and Southern blot confirmed insertion of a single GFP expression cassette into the target site of the SaHV-1 genome. The recombinant virus was shown to produce strong fluorescence in the cytoplasm of infected cells in vitro . Growth kinetic experiments demonstrated no differences between recombinant and wild type SaHV-1 in producing infectious progeny virions. The recombinant virus was comparable to wild type SaHV-1 in development of clinical disease, microscopic lesions and induction of an antibody response in mice following intramuscular inoculation. Using confocal microscopy, GFP expression was easily observed in formalin fixed, paraffin-embedded tissues of mice infected with the recombinant SaHV-1. This simple specimen processing technique preserves tissue morphology and allows detection of viral replication within various tissues of experimentally infected animals.
