scholarly journals Development of whole-porcine monoclonal antibodies with potent neutralization activity against classical swine fever virus (CSFV) from single B cells

2018 ◽  
Author(s):  
Haisi Dong ◽  
Dongmei Lv ◽  
Ang Su ◽  
Lerong Ma ◽  
Jianwei Dong ◽  
...  

AbstractClassical swine fever (CSF) is a highly contagious swine disease found worldwide that has caused devastating economic losses. However, there are few efficacious mAbs against the CSF virus (CSFV) that can be used for treatment because most mAbs against CSFV are derived from mouse hybridoma cells and these murine mAbs have disadvantages of inefficient effector functions elicitations and high immunogenicity in vivo. Accordingly, we characterized whole-porcine anti-CSFV neutralizing mAbs (NAbs) isolated directly from single B cells sorted from a CSFV-vaccinated pig using the fluoresceinated conserved linear neutralizing epitope of the CSFV E2 protein and fluorophore conjugated goat anti-pig IgG. Immunoglobulin (Ig) genes were isolated via nested PCR, and two porcine mAbs termed HK24 and HK44 were produced. We determined that these mAbs can bind to E2 protein and recognize sites within this major antigenic epitope. In addition, we found that mAbs HK24 and HK44 exhibit potent neutralizing activity against CSFV, and they can protect PK-15 cells from infections in vitro with potent IC50 values of 9.3 μg/ml and 0.62 μg/ml, respectively. Notably, we demonstrated that these two mAbs can be used as novel reagents for detecting virus infection. These data suggest that our results not only provide a method for efficiently obtaining mAbs against CSFV but also offer promising mAb candidates for development of antibody-based diagnostic and antiviral agents.ImportanceNeutralizing monoclonal antibodies (NAbs) can prevent and may slow the spread of virus infection. The discovery of NAbs that recognize classical swine fever virus (CSFV) necessitates new technologies because the NAbs produced by immunization and hybridoma technology could not be transferred to in vivo research. Multiple full-length human therapeutic antibodies have been produced via single-cell polymerase chain reactions but whole-porcine NAbs for CSFV have not been generated. In this study, two whole-porcine mAbs, named HK24 and HK44, were isolated from epitope-specific single B cells. We demonstrate that these two mAbs have potent neutralizing activity against CSFV and can protect cells against viral infection. Therefore, they may facilitate the development of vaccines or antiviral drugs that offer the advantages of stability and low immunogenicity.

2015 ◽  
Vol 81 (11) ◽  
pp. 3745-3752 ◽  
Author(s):  
Yi-Gang Xu ◽  
Xue-Ting Guan ◽  
Zhong-Mei Liu ◽  
Chang-Yong Tian ◽  
Li-Chun Cui

ABSTRACTClassical swine fever, caused by classical swine fever virus (CSFV), is a highly contagious disease that results in enormous economic losses in pig industries. The E2 protein is one of the main structural proteins of CSFV and is capable of inducing CSFV-neutralizing antibodies and cytotoxic T lymphocyte (CTL) activitiesin vivo. Thymosin α-1 (Tα1), an immune-modifier peptide, plays a very important role in the cellular immune response. In this study, genetically engineeredLactobacillus plantarumbacteria expressing CSFV E2 protein alone (L. plantarum/pYG-E2) and in combination with Tα1 (L. plantarum/pYG-E2-Tα1) were developed, and the immunogenicity of each as an oral vaccine to induce protective immunity against CSFV in pigs was evaluated. The results showed that recombinantL. plantarum/pYG-E2 andL. plantarum/pYG-E2-Tα1 were both able to effectively induce protective immune responses in pigs against CSFV infection by eliciting immunoglobulin A (IgA)-based mucosal, immunoglobulin G (IgG)-based humoral, and CTL-based cellular immune responses via oral vaccination. Significant differences (P< 0.05) in the levels of immune responses were observed betweenL. plantarum/pYG-E2-Tα1 andL. plantarum/pYG-E2, suggesting a better immunogenicity ofL. plantarum/pYG-E2-Tα1 as a result of the Tα1 molecular adjuvant that can enhance immune responsiveness and augment specific lymphocyte functions. Our data suggest that the recombinantLactobacillusmicroecological agent expressing CSFV E2 protein combined with Tα1 as an adjuvant provides a promising strategy for vaccine development against CSFV.


Hybridoma ◽  
2012 ◽  
Vol 31 (5) ◽  
pp. 340-346 ◽  
Author(s):  
Mariko Moniwa ◽  
Lizhong Luo ◽  
Kevin Hills ◽  
Krista Nishi ◽  
Erin MacLeod ◽  
...  

2018 ◽  
Author(s):  
Zicong Xie ◽  
Daxin Pang ◽  
Hongming Yuan ◽  
Huping Jiao ◽  
Chao Lu ◽  
...  

AbstractClassical swine fever (CSF) caused by classical swine fever virus (CSFV) is among the most detrimental diseases, and leads to significant economic losses in the swine industry. Despite efforts by many government authorities try to stamp out the disease from national pig populations, the disease remains widespread. Here, antiviral small hairpin RNAs (shRNAs) were selected and then inserted at the porcine ROSA26 (pROSA26) locus via a CRISPR/Cas9-mediated knock-in strategy. Finally, anti-CSFV transgenic (TG) pigs were produced by somatic nuclear transfer (SCNT). Importantly, in vitro and in vivo viral challenge assays demonstrated that these TG pigs could effectively limit the growth of CSFV and reduced CSFV-associated clinical signs and mortality, and the disease resistance was stably transmitted to F1-generation. The use of these TG pigs can improve the well-being of livestock and substantially reduce virus-related economic losses. Additionally, this antiviral approach may provide a reference for future antiviral research.Author summaryClassical swine fever (CSF), caused by classical swine fever virus (CSFV), and is a highly contagious, often fatal porcine disease with significant economic losses. Due to its economic importance to the pig industry, the biology and pathogenesis of CSFV have been investigated extensively. Despite efforts by many government authorities to stamp out the disease from national pig populations, the disease remains widespread in some regions and seems to be waiting for the reintroduction and the next round of disease outbreaks. These highlight the necessity and urgency of developing more effective approaches to eradicate the challenging CSFV. In this study, we successfully produced anti-CSFV transgenic pigs and confirmed that these transgenic pigs could effectively limit the growth of CSFV in vivo and in vitro and that the disease resistance traits in the TG founders can be stably transmitted to their F1-generation offspring. This study suggests that these TG pigs can improve the well-being of livestock and contribute to offer potential benefits over commercial vaccination. The use of these TG pigs can improve the well-being of livestock and substantially reduce CSFV-related economic losses.


2020 ◽  
Author(s):  
Huiling Xu ◽  
Yanli Wang ◽  
Guangwei Han ◽  
Weihuan Fang ◽  
fang he

Abstract Background: Outbreaks of Classical swine fever virus (CSFV) cause significant economic losses in the swine industry. Vaccination is the major method to prevent and control the disease. As live attenuated vaccines fail to elicit differentiable immunity between infected and vaccinated animals, subunit vaccine was considered as an alternative candidate to prevent and eradicate CSFV. Subunit vaccines present advantages in DIVA immunogenicity and safety. The technology was limited due to the low yield and the high cost with multiple and large doses. The native E2 signal peptide has not been well defined before. Here, the aim of this study is to develop a cost-effective and efficacious E2 vaccine candidate against CSFV with signal peptide and E2 sequence selection. Results: A novel CSFV E2 sequence (E2ZJ) was identified from an epidemic strain of Zhejiang for outstanding secretion in baculovirus and enhanced immunogenicity. E2 secretion induced with the selected signal peptide, SPZJ (SP23), increase at least 50% as compared to any other signal peptides tested. Besides, unique antigenic features were identified in E2ZJ. E2ZJ elicited CSFV antibodies at the earlier stage than other E2 types tested in mice. Moreover, higher level of neutralization antibodies against both genotypes 1 and 2 CSFV with E2ZJ was detected than other E2s with the same dosage. Further, in piglets, E2ZJ successfully elicited neutralizing immunity. A single dose of 5 μg of E2ZJ was sufficient to induce protective antibodies against CSFV in piglets and provided 100% protection against lethal virus challenge. Conclusions: Our studies provide evidence that E2ZJ guided by a novel E2 signal peptide (SPZJ) was efficiently secreted and presented significantly improved immunogenicity than conventional E2 vaccines. Moreover, a single dose of 5 μg E2ZJ is efficacious against CSFV in piglets. Keywords: Classical swine fever virus; novel signal peptide; SPZJ-E2ZJ; subunit vaccine; protective immunity


2006 ◽  
Vol 37 (1) ◽  
pp. 155-168 ◽  
Author(s):  
Henriette Rau ◽  
Hilde Revets ◽  
Carole Balmelli ◽  
Kenneth C. McCullough ◽  
Artur Summerfield

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