scholarly journals Differential Effects on Cell Fusion Activity of Mutations in Herpes Simplex Virus 1 Glycoprotein B (gB) Dependent on Whether a gD Receptor or a gB Receptor Is Overexpressed

2009 ◽  
Vol 83 (15) ◽  
pp. 7384-7390 ◽  
Author(s):  
Qing Fan ◽  
Erick Lin ◽  
Takeshi Satoh ◽  
Hisashi Arase ◽  
Patricia G. Spear
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Fusion ◽  
Viral Entry ◽  
Selective Reduction ◽  
Glycoprotein B ◽  
Fusion Activity ◽  
Differential Effects ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Glycoprotein B (gB) of herpes simplex virus (HSV) is one of four glycoproteins essential for viral entry and cell fusion. Recently, paired immunoglobulin-like type 2 receptor (PILRα) was identified as a receptor for HSV type 1 (HSV-1) gB. Both PILRα and a gD receptor were shown to participate in HSV-1 entry into certain cell types. The purpose of this study was to determine whether insertional mutations in gB had differential effects on its function with PILRα and the gD receptor, nectin-1. Previously described gB mutants and additional newly characterized mutants were used in this study. We found that insertional mutations near the N terminus and C terminus of gB and especially in the central region of the ectodomain reduced cell fusion activity when PILRα was overexpressed much more than when nectin-1 was overexpressed. Most of the insertions reduced the binding of gB to PILRα, for at least some forms of gB, but this reduction did not necessarily correlate with the selective reduction in cell fusion activity with PILRα. These results suggest that the regions targeted by the relevant mutations are critical for functional activity with PILRα. They also suggest that, although both the binding of gB to a gB receptor and the binding of gD to a gD receptor may be required for HSV-induced cell fusion, the two receptor-binding activities may have unequal weights in triggering fusogenic activity, depending on the ratios of gB and gD receptors or other factors.

scholarly journals Multiple Peptides Homologous to Herpes Simplex Virus Type 1 Glycoprotein B Inhibit Viral Infection

2008 ◽  
Vol 53 (3) ◽  
pp. 987-996 ◽  
Author(s):  
Radeekorn Akkarawongsa ◽  
Nina E. Pocaro ◽  
Gary Case ◽  
Aaron W. Kolb ◽  
Curtis R. Brandt
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Viral Entry ◽  
Herpes Simplex Virus Type ◽  
Glycoprotein B ◽  
Induced Mutations ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The 773-residue ectodomain of the herpes simplex virus type 1 (HSV-1) glycoprotein B (gB) has been resistant to the use of mutagenic strategies because the majority of the induced mutations result in defective proteins. As an alternative strategy for the identification of functionally important regions and novel inhibitors of infection, we prepared a library of overlapping peptides homologous to the ectodomain of gB and screened for the ability of the peptides to block infection. Seven of 138 15-mer peptides inhibited infection by more than 50% at a concentration of 100 μM. Three peptides (gB94, gB122, and gB131) with 50% effective concentrations (EC50s) below 20 μM were selected for further studies. The gB131 peptide (residues 681 to 695 in HSV-1 gB [gB-1]) was a specific entry inhibitor (EC50, ∼12 μM). The gB122 peptide (residues 636 to 650 in gB-1) blocked viral entry (EC50, ∼18 μM), protected cells from infection (EC50, ∼72 μM), and inactivated virions in solution (EC50, ∼138 μM). We were unable to discern the step or steps inhibited by the gB94 peptide, which is homologous to residues 496 to 510 in gB-1. Substitution of a tyrosine in the gB122 peptide (Y640 in full-length gB-1) reduced the antiviral activity eightfold, suggesting that this residue is critical for inhibition. This peptide-based strategy could lead to the identification of functionally important regions of gB or other membrane proteins and identify novel inhibitors of HSV-1 entry.

scholarly journals HveA (Herpesvirus Entry Mediator A), a Coreceptor for Herpes Simplex Virus Entry, also Participates in Virus-Induced Cell Fusion

1998 ◽  
Vol 72 (7) ◽  
pp. 5802-5810 ◽  
Author(s):  
Tracy Terry-Allison ◽  
Rebecca I. Montgomery ◽  
J. Charles Whitbeck ◽  
Ruliang Xu ◽  
Gary H. Cohen ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Fusion ◽  
Viral Entry ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Simplex Virus ◽  
Herpesvirus Entry Mediator ◽  
Hsv 1 ◽  
Cell Cell

ABSTRACT The purpose of this study was to determine whether a cell surface protein that can serve as coreceptor for herpes simplex virus type 1 (HSV-1) entry, herpesvirus entry mediator (previously designated HVEM but renamed HveA), also mediates HSV-1-induced cell-cell fusion. We found that transfection of DNA from KOS-804, a previously described HSV-1 syncytial (Syn) strain whose Syn mutation was mapped to an amino acid substitution in gK, induced numerous large syncytia on HveA-expressing Chinese hamster ovary cells (CHO-HVEM12) but not on control cells (CHO-C8). Antibodies specific for gD as well as for HveA were effective inhibitors of KOS-804-induced fusion, consistent with previously described direct interactions between gD and HveA. Since mutations in gD determine the ability of HSV-1 to utilize HveA for entry, we examined whether the form of virally expressed gD also influenced the ability of HveA to mediate fusion. We produced a recombinant virus carrying the KOS-804 Syn mutation and the KOS-Rid1 gD mutation, which significantly reduces viral entry via HveA, and designated it KOS-SR1. KOS-SR1 DNA had a markedly reduced ability to induce syncytia on CHO-HVEM12 cells and a somewhat enhanced ability to induce syncytia on CHO-C8 cells. These results support previous findings concerning the relative abilities of KOS and KOS-Rid1 to infect CHO-HVEM12 and CHO-C8 cells. Thus, HveA mediates cell-cell fusion as well as viral entry and both activities of HveA are contingent upon the form of gD expressed by the virus.

scholarly journals Insertion Mutations in Herpes Simplex Virus 1 Glycoprotein H Reduce Cell Surface Expression, Slow the Rate of Cell Fusion, or Abrogate Functions in Cell Fusion and Viral Entry

2009 ◽  
Vol 84 (4) ◽  
pp. 2038-2046 ◽  
Author(s):  
Julia O. Jackson ◽  
Erick Lin ◽  
Patricia G. Spear ◽  
Richard Longnecker
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Surface ◽  
Cell Fusion ◽  
Viral Entry ◽  
Cytoplasmic Tail ◽  
Target Cells ◽  
Simplex Virus ◽  
Insertion Mutations ◽  
Hsv 1

ABSTRACT Of the four required herpes simplex virus (HSV) entry glycoproteins, the precise role of gH-gL in fusion remains the most elusive. The heterodimer gH-gL has been proposed to mediate hemifusion after the interaction of another required glycoprotein, gD, with a receptor. To identify functional domains of HSV-1 gH, we generated 22 randomized linker-insertion mutants. Analyses of 22 gH mutants revealed that gH is relatively tolerant of insertion mutations, as 15 of 22 mutants permitted normal processing and transport of gH-gL to the cell surface. gH mutants that were not expressed well at the cell surface did not function in fusion or viral entry. The screening of gH mutants for function revealed the following: (i) for wild-type gH and some gH mutants, fusion with nectin-1-expressing target cells occurred more rapidly than with herpesvirus entry mediator (HVEM)-expressing target cells; (ii) some gH mutants reduced the rate of cell fusion without abrogating fusion completely, indicating that gH may play a role in governing the kinetics of fusion and may be responsible for a rate-limiting first stage in HSV-1 fusion; and (iii) only one gH mutant, located within the short cytoplasmic tail, completely abrogated function, indicating that the gH cytoplasmic tail is crucial for cell fusion and viral infectivity.

Expression of herpes simplex virus beta and gamma genes integrated in mammalian cells and their induction by an alpha gene product

1983 ◽  
Vol 3 (11) ◽  
pp. 2028-2044
Author(s):  
R M Sandri-Goldin ◽  
A L Goldin ◽  
L E Holland ◽  
J C Glorioso ◽  
M Levine
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Binding ◽  
Gene Product ◽  
Mammalian Cells ◽  
Dna Binding Protein ◽  
Glycoprotein B ◽  
Alpha Gene ◽  
Simplex Virus ◽  
Hsv 1

The proteins of herpes simplex virus type 1 (HSV-1) form three kinetic groups termed alpha, beta, and gamma, whose synthesis is regulated in a cascade fashion. alpha products are synthesized first during infection, and they are required for synthesis of beta and gamma proteins. To examine the expression of several HSV-1 beta and gamma genes in the absence of alpha functions, we transferred into mammalian cells a plasmid containing a region of the HSV-1 genome that codes for only beta and gamma genes (0.315 to 0.421 map units). We found stable integration of at least one copy of the intact plasmid in each cell line. Four HSV-1 transcripts of the beta and gamma classes were transcribed constitutively in the cells, including the genes for glycoprotein B and DNA-binding protein. No constitutive synthesis of these two proteins could be demonstrated, however. The integrated HSV-1 genes responded to viral regulatory signals in that they could be induced by infection with HSV-1 mutants resulting in a high level of synthesis of both glycoprotein B and DNA-binding protein. The HSV-1 alpha gene product ICP4 was necessary for this induction, and it was found to be most efficient at a low multiplicity of infection. Functional expression of four genes was demonstrated in that the cell lines complemented infecting HSV-1 temperature-sensitive mutants. The same genes were not available for homologous recombination with infecting virus, however, since no recombinant wild-type virus could be detected. These data demonstrate that HSV-1 beta and gamma genes can be transcribed in the absence of alpha functions in mammalian cells, but that they still respond to HSV-1 regulatory signals such as the alpha gene product ICP4.

scholarly journals Soluble V Domain of Nectin-1/HveC Enables Entry of Herpes Simplex Virus Type 1 (HSV-1) into HSV-Resistant Cells by Binding to Viral Glycoprotein D

2006 ◽  
Vol 80 (1) ◽  
pp. 138-148 ◽  
Author(s):  
Heechung Kwon ◽  
Qing Bai ◽  
Hyun-Jung Baek ◽  
Kelly Felmet ◽  
Edward A. Burton ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Cell Surface ◽  
Viral Entry ◽  
Glycoprotein D ◽  
Viral Glycoprotein ◽  
Virus Attachment ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Interaction of herpes simplex virus (HSV) glycoprotein D (gD) with specific cellular receptors is essential for HSV infection of susceptible cells. Virus mutants that lack gD can bind to the cell surface (attachment) but do not enter, implying that interaction of gD with its receptor(s) initiates the postattachment (entry) phase of HSV infection. In this report, we have studied HSV entry in the presence of the gD-binding variable (V) domain of the common gD receptor nectin-1/HveC to determine whether cell association of the gD receptor is required for HSV infection. In the presence of increasing amounts of the soluble nectin-1 V domain (sNec1123), increasing viral entry into HSV-resistant CHO-K1 cells was observed. At a multiplicity of 3 in the presence of optimal amounts of sNec1123, approximately 90% of the cells were infected. The soluble V domain of nectin-2, a strain-specific HSV entry receptor, promoted entry of the HSV type 1 (HSV-1) Rid-1 mutant strain, but not of wild-type HSV-1. Preincubation and immunofluorescence studies indicated that free or gD-bound sNec1123 did not associate with the cell surface. sNec1123-mediated entry was highly impaired by interference with the cell-binding activities of viral glycoproteins B and C. While gD has at least two functions, virus attachment to the cell and initiation of the virus entry process, our results demonstrate that the attachment function of gD is dispensable for entry provided that other means of attachment are available, such as gB and gC binding to cell surface glycosaminoglycans.

scholarly journals Binding of Herpes Simplex Virus Glycoprotein B (gB) to Paired Immunoglobulin-Like Type 2 Receptor α Depends on Specific Sialylated O-Linked Glycans on gB

2009 ◽  
Vol 83 (24) ◽  
pp. 13042-13045 ◽  
Author(s):  
Jing Wang ◽  
Qing Fan ◽  
Takeshi Satoh ◽  
Jun Arii ◽  
Lewis L. Lanier ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Herpes Simplex Virus Type ◽  
Glycoprotein B ◽  
Inhibitory Receptor ◽  
Herpes Simplex Virus Glycoprotein ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Paired immunoglobulin-like type 2 receptor α (PILRα) is an inhibitory receptor expressed on both hematopoietic and nonhematopoietic cells. Its binding to a cellular ligand, CD99, depends on the presence of sialylated O-linked glycans on CD99. Glycoprotein B (gB) of herpes simplex virus type 1 (HSV-1) binds to PILRα, and this association is involved in HSV-1 infection. Here, we found that the presence of sialylated O-glycans on gB is required for gB to associate with PILRα. Furthermore, we identified two threonine residues on gB that are essential for the addition of the principal O-glycans acquired by gB and that are also essential for the binding of PILRα to gB.

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