scholarly journals Effect of specific amino acid substitutions in the putative fusion peptide of structural glycoprotein E2 on Classical Swine Fever Virus replication

Virology ◽  
2014 ◽  
Vol 456-457 ◽  
pp. 121-130 ◽  
Author(s):  
I.J. Fernández-Sainz ◽  
E. Largo ◽  
D.P. Gladue ◽  
P. Fletcher ◽  
V. O’Donnell ◽  
...  
Keyword(s):  
Amino Acid ◽  
Virus Replication ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fusion Peptide ◽  
Fever Virus ◽  
Amino Acid Substitutions ◽  
Specific Amino Acid ◽  
Glycoprotein E2

scholarly journals Alteration of a Second Putative Fusion Peptide of Structural Glycoprotein E2 of Classical Swine Fever Virus Alters Virus Replication and Virulence in Swine

2016 ◽  
Vol 90 (22) ◽  
pp. 10299-10308 ◽  
Author(s):  
L. G. Holinka ◽  
E. Largo ◽  
D. P. Gladue ◽  
V. O'Donnell ◽  
G. R. Risatti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Structural Analysis ◽  
Cell Cultures ◽  
Classical Swine Fever Virus ◽  
Synthetic Peptides ◽  
Classical Swine Fever ◽  
Fusion Peptide ◽  
Fever Virus ◽  
Amino Acid Substitutions ◽  
Artificial Membranes

ABSTRACTE2, the major envelope glycoprotein of classical swine fever virus (CSFV), is involved in several critical virus functions, including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on a Wimley-White interfacial hydrophobicity distribution predicted the involvement of a loop (residues 864 to 881) stabilized by a disulfide bond (869CKWGGNWTCV878, named FPII) in establishing interactions with the host cell membrane. This loop further contains an872GG873dipeptide, as well as two aromatic residues (871W and875W) accessible to solvent. Reverse genetics utilizing a full-length infectious clone of the highly virulent CSFV strain Brescia (BICv) was used to evaluate how amino acid substitutions within FPII may affect replication of BICvin vitroand virus virulence in swine. Recombinant CSFVs containing mutations in different residues of FPII were constructed. A particular construct, harboring amino acid substitutions W871T, W875D, and V878T (FPII.2), demonstrated a significantly decreased ability to replicate in a swine cell line (SK6) and swine macrophage primary cell cultures. Interestingly, mutated virus FPII.2 was completely attenuated in pigs. Also, animals infected with FPII.2 virus were protected against virulent challenge with Brescia virus at 21 days postvaccination. Supporting a role for the E2 the loop from residues 864 to 881 in membrane fusion, only synthetic peptides that were based on the native E2 functional sequence were competent for insertion into model membranes and perturbation of their integrity, and this functionality was lost in synthetic peptides harboring amino acid substitutions W871T, W875D, and V878T in FPII.2.IMPORTANCEThis report describes the identification and characterization of a putative fusion peptide (FP) in the major structural protein E2 of classical swine fever virus (CSFV). The FP identification was performed by functional structural analysis of E2. We characterized the functional significance of this FP by using artificial membranes. Replacement of critical amino acid residues within the FP radically alters how it interacts with the artificial membranes. When we introduced the same mutations into the viral sequence, there was a reduction in replication in cell cultures, and when we infected domestic swine, the natural host of CSFV host, we observed that the virus was now completely attenuated in swine. In addition, the virus mutant that was attenuatedin vivoefficiently protected pigs against wild-type virus. These results provide the proof of principle to support as a strategy for vaccine development the discovery and manipulation of FPs.

scholarly journals Swine Host Protein Coiled-Coil Domain-Containing 115 (CCDC115) Interacts with Classical Swine Fever Virus Structural Glycoprotein E2 during Virus Replication

Viruses ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 388 ◽  
Author(s):  
Elizabeth A. Vuono ◽  
Elizabeth Ramirez-Medina ◽  
Keith Berggren ◽  
Ayushi Rai ◽  
Sarah Pruitt ◽  
...  
Keyword(s):  
Amino Acid ◽  
Virus Replication ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Host Protein ◽  
Yeast Two Hybrid ◽  
Host Proteins ◽  
E2 Protein ◽  
Two Hybrid

Interactions between the major structural glycoprotein E2 of classical swine fever virus (CSFV) with host proteins have been identified as important factors affecting virus replication and virulence. Previously, using the yeast two-hybrid system, we identified swine host proteins specifically interacting with CSFV E2. In this report, we use a proximity ligation assay to demonstrate that swine host protein CCDC115 interacts with E2 in CSFV-infected swine cells. Using a randomly mutated E2 library in the context of a yeast two-hybrid methodology, specific amino acid mutations in the CSFV E2 protein responsible for disrupting the interaction with CCDC115 were identified. A recombinant CSFV mutant (E2ΔCCDC115v) harboring amino acid changes disrupting the E2 protein interaction with CCDC115 was produced and used as a tool to assess the role of the E2–CCDC115 interaction in viral replication and virulence in swine. CSFV E2ΔCCDC115v showed a slightly decreased ability to replicate in the SK6 swine cell line and a greater replication defect in primary swine macrophage cultures. A decreased E2–CCDC115 interaction detected by PLA is observed in cells infected with E2ΔCCDC115v. Importantly, animals intranasally infected with 105 TCID50 of E2ΔCCDC115v experienced a significantly longer survival period when compared with those infected with the parental Brescia strain. This result would indicate that the ability of CSFV E2 to bind host CCDC115 protein during infection plays an important role in virus replication in swine macrophages and in virus virulence during the infection in domestic swine.

scholarly journals Selection of Classical Swine Fever Virus with Enhanced Pathogenicity Reveals Synergistic Virulence Determinants in E2 and NS4B

2012 ◽  
Vol 86 (16) ◽  
pp. 8602-8613 ◽  
Author(s):  
Tomokazu Tamura ◽  
Yoshihiro Sakoda ◽  
Fumi Yoshino ◽  
Takushi Nomura ◽  
Naoki Yamamoto ◽  
...  
Keyword(s):  
Amino Acid ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
Amino Acid Substitutions ◽  
Virulence Determinants ◽  
Live Attenuated Vaccine

Classical swine fever virus (CSFV) is the causative agent of classical swine fever (CSF), a highly contagious disease of pigs. There are numerous CSFV strains that differ in virulence, resulting in clinical disease with different degrees of severity. Low-virulent and moderately virulent isolates cause a mild and often chronic disease, while highly virulent isolates cause an acute and mostly lethal hemorrhagic fever. The live attenuated vaccine strain GPE−was produced by multiple passages of the virulent ALD strain in cells of swine, bovine, and guinea pig origin. With the aim of identifying the determinants responsible for the attenuation, the GPE−vaccine virus was readapted to pigs by serial passages of infected tonsil homogenates until prolonged viremia and typical signs of CSF were observed. The GPE−/P-11 virus isolated from the tonsils after the 11th passagein vivohad acquired 3 amino acid substitutions in E2 (T830A) and NS4B (V2475A and A2563V) compared with the virus before passages. Experimental infection of pigs with the mutants reconstructed by reverse genetics confirmed that these amino acid substitutions were responsible for the acquisition of pathogenicity. Studiesin vitroindicated that the substitution in E2 influenced virus spreading and that the changes in NS4B enhanced the viral RNA replication. In conclusion, the present study identified residues in E2 and NS4B of CSFV that can act synergistically to influence virus replication efficiencyin vitroand pathogenicity in pigs.

scholarly journals Novel poly-uridine insertion in the 3′UTR and E2 amino acid substitutions in a low virulent classical swine fever virus

2017 ◽  
Vol 201 ◽  
pp. 103-112 ◽  
Author(s):  
Liani Coronado ◽  
Matthias Liniger ◽  
Sara Muñoz-González ◽  
Alexander Postel ◽  
Lester Josue Pérez ◽  
...  
Keyword(s):  
Amino Acid ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Amino Acid Substitutions

scholarly journals Complex Virus–Host Interactions Involved in the Regulation of Classical Swine Fever Virus Replication: A Minireview

Viruses ◽  
2017 ◽  
Vol 9 (7) ◽  
pp. 171 ◽  
Author(s):  
Su Li ◽  
Jinghan Wang ◽  
Qian Yang ◽  
Muhammad Naveed Anwar ◽  
Shaoxiong Yu ◽  
...  
Keyword(s):  
Virus Replication ◽  
Classical Swine Fever Virus ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Host Interactions

Efficacy and stability of a subunit vaccine based on glycoprotein E2 of classical swine fever virus

1999 ◽  
Vol 66 (2) ◽  
pp. 101-114 ◽  
Author(s):  
A Bouma ◽  
A.J de Smit ◽  
E.P de Kluijver ◽  
C Terpstra ◽  
R.J.M Moormann
Keyword(s):  
Classical Swine Fever Virus ◽  
Subunit Vaccine ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
A Subunit ◽  
Glycoprotein E2

scholarly journals Optimal Conditions for the Expression of Glycoprotein E2 of Classical Swine Fever Virus using Baculovirus in Insect Cells

2014 ◽  
Vol 29 (2) ◽  
pp. 207-213
Author(s):  
Sung Min Bae ◽  
Seung Hee Lee ◽  
Won Suk Kwak ◽  
Yong Oh Ahn ◽  
Tae Young Shin ◽  
...  
Keyword(s):  
Classical Swine Fever Virus ◽  
Insect Cells ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
Optimal Conditions ◽  
Glycoprotein E2

scholarly journals P108 and T109 on E2 Glycoprotein Domain I Are Critical for the Adaptation of Classical Swine Fever Virus to Rabbits but Not for Virulence in Pigs

2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Libao Xie ◽  
Yuying Han ◽  
Yuteng Ma ◽  
Mengqi Yuan ◽  
Weike Li ◽  
...  
Keyword(s):  
Viral Entry ◽  
Classical Swine Fever Virus ◽  
Molecular Basis ◽  
Classical Swine Fever ◽  
Fever Virus ◽  
E2 Glycoprotein ◽  
Viral Adaptation ◽  
Glycoprotein E2 ◽  
Domain I ◽  
Highly Virulent

ABSTRACT The classical swine fever virus (CSFV) live attenuated vaccine C-strain is adaptive to rabbits and attenuated in pigs, in contrast with the highly virulent CSFV Shimen strain. Previously, we demonstrated that P108 and T109 on the E2 glycoprotein (E2P108-T109) in domain I (E2DomainI) rather than R132, S133, and D191 in domain II (E2DomainII) determine C-strain’s adaptation to rabbits (ATR) (Y. Li, L. Xie, L. Zhang, X. Wang, C. Li, et al., Virology 519:197–206, 2018). However, it remains elusive whether these critical amino acids affect the ATR of the Shimen strain and virulence in pigs. In this study, three chimeric viruses harboring E2P108-T109, E2DomainI, or E2DomainII of C-strain based on the non-rabbit-adaptive Shimen mutant vSM-HCLVErns carrying the Erns glycoprotein of C-strain were generated and evaluated. We found that E2P108-T109 or E2DomainI but not E2DomainII of C-strain renders vSM-HCLVErns adaptive to rabbits, suggesting that E2P108-T109 in combination with the Erns glycoprotein (E2P108-T109-Erns) confers ATR on the Shimen strain, creating new rabbit-adaptive CSFVs. Mechanistically, E2P108-T109-Erns of C-strain mediates viral entry during infection in rabbit spleen lymphocytes, which are target cells of C-strain. Notably, pig experiments showed that E2P108-T109-Erns of C-strain does not affect virulence compared with the Shimen strain. Conversely, the substitution of E2DomainII and Erns of C-strain attenuates the Shimen strain in pigs, indicating that the molecular basis of the CSFV ATR and that of virulence in pigs do not overlap. Our findings provide new insights into the mechanism of adaptation of CSFV to rabbits and the molecular basis of CSFV adaptation and attenuation. IMPORTANCE Historically, live attenuated vaccines produced by blind passage usually undergo adaptation in cell cultures or nonsusceptible hosts and attenuation in natural hosts, with a classical example being the classical swine fever virus (CSFV) lapinized vaccine C-strain, which was developed by hundreds of passages in rabbits. However, the mechanism of viral adaptation to nonsusceptible hosts and the molecular basis for viral adaptation and attenuation remain largely unknown. In this study, we demonstrated that P108 and T109 on the E2 glycoprotein together with the Erns glycoprotein of the rabbit-adaptive C-strain confer adaptation to rabbits on the highly virulent CSFV Shimen strain by affecting viral entry during infection but do not attenuate the Shimen strain in pigs. Our results provide vital information on the different molecular bases of CSFV adaptation to rabbits and attenuation in pigs.

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