scholarly journals Correlation of Neutralizing Antibodies (NAbs) between Sows and Piglets and Evaluation of Protectability Associated with Maternally Derived NAbs in Pigs against Circulating Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) under Field Conditions

Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 414
Author(s):  
Fu-Chun Hsueh ◽  
Sheng-Yuan Wang ◽  
Wei-Hao Lin ◽  
Chuen-Fu Lin ◽  
Chen-Yu Tsai ◽  
...  
Keyword(s):  
Viral Infection ◽  
Neutralizing Antibodies ◽  
Respiratory Symptoms ◽  
Survival Rates ◽  
Field Conditions ◽  
Respiratory Syndrome Virus ◽  
Reproductive Disorders ◽  
Nursery Pigs ◽  
Viral Loads ◽  
Natural Outbreak

Porcine reproductive and respiratory syndrome (PRRS), which is caused by a highly transmissible pathogen called porcine reproductive and respiratory syndrome virus (PRRSV), has caused severe problems, including reproductive disorders in sows and respiratory symptoms in nursery pigs worldwide, since the early 1990s. However, currently available PRRSV vaccines do not supply complete immunity to confront the viral infection. Elicitation of PRRSV-specific neutralizing antibodies (NAbs) during the preinfectious period has been deemed to be a feasible strategy to modulate this virus, especially in farms where nursery pigs are seized with PRRSVs. A total of 180 piglets in a farrow-to-finish farm that had a natural outbreak of PRRS were distributed into three groups based on the different PRRSV NAbs levels in their dams. In the present study, piglets that received superior maternal-transferred NAbs showed delayed and relatively slight viral loads in serum and, on the whole, higher survival rates against wild PRRSV infections. A positive correlation of maternal NAbs between sows and their piglets was identified; moreover, high NAbs titers in piglets can last for at least 4 weeks. These results provide updated information to develop an appropriate immune strategy for breeding and for future PRRSV control under field conditions.

scholarly journals Effects of high molecular weight poly-γ-glutamic acid on PIGS with porcine preproductive and respiratory syndrome virus (PRRSV) infection

2017 ◽  
Vol 67 (2) ◽  
pp. 153-167
Author(s):  
Byoung-Joo Seo ◽  
Jee-Hoon Lee ◽  
Ick-Jae Kang ◽  
Nadeem Shabir ◽  
Amina Khatun ◽  
...  
Keyword(s):  
Glutamic Acid ◽  
Molecular Mass ◽  
Neutralizing Antibodies ◽  
Respiratory Syndrome Virus ◽  
Control Group ◽  
Treatment Groups ◽  
Viral Loads ◽  
Challenge Study ◽  
Tnf Α ◽  
Prrsv Strain

Abstract Bacillus subtilis sups. chungkookjang produces a higher molecular mass poly-γ-glutamic acid (γ-PGA). Recently, previous studies have demonstrated immune stimulation and an antitumor effect of the high molecular mass γ-PGA using various mouse models although these effects have not been shown in other species of animals. Therefore, the current study was conducted to determine the effect of γ-PGA in pigs with and without PRRSV infection. PRRS-negative pigs were intramuscularly injected with 1, 3, or 5 ml of 20 mg/mll γ-PGA, and one group of pigs served as a non-treatment (NT) group. All groups treated with γ-PGA had significantly higher weight gains, and pigs treated with 5 ml of γ-PGA exhibited higher tumor necrosis factor (TNF)-α, interferon (IFN)-α and IFN-β expression levels compared with the NT group. According to the preliminary results, an animal challenge study was conducted with a highly virulent PRRSV strain, MN184, along with γ-PGA treatment at different time points. Pigs treated with γ-PGA had lower levels of viral loads in the sera and in lungs and gained significantly more weight (p<0.05) compared with the NT group after being challenged with MN184. Moreover, γ-PGA-treatment groups had higher levels of neutralizing antibodies and cytokines related to proinflammatory, humoral and cell-mediated responses than the control group after the PRRSV challenge. Therefore, it was concluded that γ-PGA induces higher levels of immune responses and increases resistance to PRRSV infection in pigs.

scholarly journals CD4 T-Cell-Independent Antibody Response Reduces Enterovirus 71 Lethality in Mice by Decreasing Tissue Viral Loads

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Li-Chiu Wang ◽  
Chia-Min Kao ◽  
Pin Ling ◽  
Ih-Jen Su ◽  
Tung-Miao Chang ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antibody Response ◽  
Viral Infection ◽  
Neutralizing Antibodies ◽  
Enterovirus 71 ◽  
Cd4 T Cell ◽  
Wild Type ◽  
Viral Loads ◽  
Deficient Mice

Enterovirus 71 (EV71) has induced fatal encephalitis in hundreds of thousands of infants and young children in the Asia-Pacific region since the past decade. Lymphocyte and antibody responses have been suspected to aggravate EV71-induced neurological symptoms, so anti-inflammatory agents have been used to treat patients with neurological symptoms. In the present study, we found that mice deficient in CD4+T cells were resistant to EV71 infection as wild-type mice, whereas mice deficient in B cells were highly susceptible to viral infection. Compensation of CD4 T-cell function by other immune cells was not likely, because wild-type mice depleted of CD4+T cells were also resistant to viral infection. Infected CD4 T-cell-deficient mice produced virus-specific neutralizing antibodies, IgM and IgG. Moreover, adoptive transfer of the virus-specific antibody produced by infected CD4 T-cell-deficient mice protected B-cell-deficient mice from infection by reducing tissue viral loads. Collectively, our results show that the CD4 T-cell-independent antibody response promotes the survival of EV71-infected mice and suggest great potential for the use of vaccines and neutralizing antibodies to reduce fatal symptoms in patients.

SARS-CoV-2 Biology Insights, Part IV.Antibody-Dependent Enhancement (ADE) and the tricky “Herd Immunity”: narrative review (Preprint)

2020 ◽  
Author(s):  
Laura Lafon-Hughes
Keyword(s):  
Viral Infection ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Whooping Cough ◽  
Common Knowledge ◽  
Herd Immunity ◽  
Life Quality ◽  
Host Cells ◽  
System P

BACKGROUND It is common knowledge that vaccination has improved our life quality and expectancy since it succeeded in achieving almost eradication of several diseases including chickenpox (varicella), diphtheria, hepatitis A and B, measles, meningococcal, mumps, pneumococcal, polio, rotavirus, rubella, tetanus and whooping cough (pertussis) Vaccination success is based on vaccine induction of neutralizing antibodies that help fight the infection (e.g. by a virus), preventing the disease. Conversely, Antibody-dependent enhancement (ADE) of a viral infection occurs when anti-viral antibodies facilitate viral entry into host cells and enhance viral infection in these cells. ADE has been previously studied in Dengue and HIV viruses and explains why a second infection with Dengue can be lethal. As already reviewed in Part I and Part II, SARS-Cov-2 shares with HIV not only 4 sequences in the Spike protein but also the capacity to attack the immune system. OBJECTIVE As HIV presents ADE, we wondered whether this was also the case regarding SARS-CoV-2. METHODS A literature review was done through Google. RESULTS SARS-CoV-2 presents ADE. As SARS, which does not have the 4 HIV-like inserts, has the same property, ADE would not be driven by the HIV-like spike sequences. CONCLUSIONS ADE can explain the failure of herd immunity-based strategies and will also probably hamper anti-SARS-CoV-2 vaccine development. As reviewed in Part I, there fortunately are promising therapeutic strategies for COVID-19, which should be further developed. In the meantime, complementary countermeasures to protect mainly the youth from this infection are presented to be discussed in Part V Viewpoint.

scholarly journals Persistence of Viremia and Production of Neutralizing Antibodies Differentially Regulated by Polymorphic APOBEC3 and BAFF-R Loci in Friend Virus-Infected Mice

2010 ◽  
Vol 84 (12) ◽  
pp. 6082-6095 ◽  
Author(s):  
Sachiyo Tsuji-Kawahara ◽  
Tomomi Chikaishi ◽  
Eri Takeda ◽  
Maiko Kato ◽  
Saori Kinoshita ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Early Stage ◽  
Chromosome 15 ◽  
Cell Repertoire ◽  
Viral Loads ◽  
Functional Polymorphisms ◽  
B Cell Repertoire ◽  
Retroviral Replication ◽  
Different Strains ◽  
Host Genes

ABSTRACT Several host genes control retroviral replication and pathogenesis through the regulation of immune responses to viral antigens. The Rfv3 gene influences the persistence of viremia and production of virus-neutralizing antibodies in mice infected with Friend mouse retrovirus complex (FV). This locus has been mapped within a narrow segment of mouse chromosome 15 harboring the APOBEC3 and BAFF-R loci, both of which show functional polymorphisms among different strains of mice. The exon 5-lacking product of the APOBEC3 allele expressed in FV-resistant C57BL/6 (B6) mice directly restricts viral replication, and mice lacking the B6-derived APOBEC3 exhibit exaggerated pathology and reduced production of neutralizing antibodies. However, the mechanisms by which the polymorphisms at the APOBEC3 locus affect the production of neutralizing antibodies remain unclear. Here we show that the APOBEC3 genotypes do not directly affect the B-cell repertoire, and mice lacking B6-derived APOBEC3 still produce FV-neutralizing antibodies in the presence of primed T helper cells. Instead, higher viral loads at a very early stage of FV infection caused by either a lack of the B6-derived APOBEC3 or a lack of the wild-type BAFF-R resulted in slower production of neutralizing antibodies. Indeed, B cells were hyperactivated soon after infection in the APOBEC3- or BAFF-R-deficient mice. In contrast to mice deficient in the B6-derived APOBEC3, which cleared viremia by 4 weeks after FV infection, mice lacking the functional BAFF-R allele exhibited sustained viremia, indicating that the polymorphisms at the BAFF-R locus may better explain the Rfv3-defining phenotype of persistent viremia.

scholarly journals Cure of Chronic Viral Infection and Virus-Induced Type 1 Diabetes by Neutralizing Antibodies

2006 ◽  
Vol 13 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Mette Ejrnaes ◽  
Matthias G. von Herrath ◽  
Urs Christen
Keyword(s):  
Type 1 Diabetes ◽  
Viral Infection ◽  
Inflammatory Mediators ◽  
Neutralizing Antibodies ◽  
Chronic Viral Infection ◽  
Negative Consequences ◽  
Ligand Interactions ◽  
The Right

The use of neutralizing antibodies is one of the most successful methods to interfere with receptor–ligand interactions in vivo. In particular blockade of soluble inflammatory mediators or their corresponding cellular receptors was proven an effective way to regulate inflammation and/or prevent its negative consequences. However, one problem that comes along with an effective neutralization of inflammatory mediators is the general systemic immunomodulatory effect. It is, therefore, important to design a treatment regimen in a way to strike at the right place and at the right time in order to achieve maximal effects with minimal duration of immunosuppression or hyperactivation. In this review, we reflect on two examples of how short time administration of such neutralizing antibodies can block two distinct inflammatory consequences of viral infection. First, we review recent findings that blockade of IL-10/IL-10R interaction can resolve chronic viral infection and second, we reflect on how neutralization of the chemokine CXCL10 can abrogate virus-induced type 1 diabetes.

scholarly journals A shorter equilibration period in the VitTrans in-straw bovine embryo vitrification method improves post-warming outcomes

2020 ◽  
Author(s):  
Iris Martínez-Rodero ◽  
Tania García-Martínez ◽  
Erika Alina Ordóñez-León ◽  
Meritxell Vendrell-Flotats ◽  
Carlos Olegario-Hidalgo ◽  
...  
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Survival Rates ◽  
Field Conditions ◽  
Bovine Embryo ◽  
Direct Transfer ◽  
Treatment Groups ◽  
Cell Counts ◽  
Hatching Rates

Abstract Background VitTrans is a device that enables the vitrification and warming/dilution of in vitro produced bovine embryos followed by their direct transfer to recipient females in field conditions. This study sought to improve the VitTrans method by comparing two equilibration times: short (SE: 3 min) and long (LE: 12 min). Outcome measures recorded in vitrified D7 and D8 expanded blastocysts were survival and hatching rates, differential cell counts, apoptosis rate and gene expression. Results While survival rates at 3 h and 24 h post-warming were reduced (P < 0.05) after vitrification, hatching rates of D7 embryos vitrified after SE were similar to those obtained in fresh non-vitrified blastocysts. Hatching rates of vitrified D8 blastocysts were lower (P < 0.05) than of fresh controls, regardless of treatment. Total cell counts, and inner cell mass and trophectoderm cell numbers were similar in hatched blastocysts derived from D7 blastocysts vitrified after SE and fresh blastocysts, while vitrified D8 blastocysts yielded lower values, regardless of treatment. The rate of apoptotic cells was significantly higher in both treatment groups when compared to fresh controls, although apoptosis rates were lower using the SE than LE protocol. No differences emerged in expression of the genes BAX, AQP3, CX43 and IFNτ between blastocysts vitrified after SE or LE, whereas a significantly higher abundance of BCL2L1 and SOD1 transcripts was observed in blastocysts vitrified after SE compared to LE. Conclusions The VitTrans device combined with a shorter exposure to the equilibration medium improves vitrification/warming outcomes facilitating the direct transfer of vitrified embryos under field conditions.

scholarly journals The Fc-mediated effector functions of a potent SARS-CoV-2 neutralizing antibody, SC31, isolated from an early convalescent COVID-19 patient, are essential for the optimal therapeutic efficacy of the antibody

PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0253487
Author(s):  
Conrad E. Z. Chan ◽  
Shirley G. K. Seah ◽  
De Hoe Chye ◽  
Shane Massey ◽  
Maricela Torres ◽  
...  
Keyword(s):  
Therapeutic Efficacy ◽  
Neutralizing Antibodies ◽  
Inflammatory Responses ◽  
Therapeutic Potential ◽  
Rhesus Macaques ◽  
Neutralizing Antibody ◽  
Effector Functions ◽  
Viral Loads ◽  
Therapeutic Doses ◽  
Dose Dependent

Although SARS-CoV-2-neutralizing antibodies are promising therapeutics against COVID-19, little is known about their mechanism(s) of action or effective dosing windows. We report the generation and development of SC31, a potent SARS-CoV-2 neutralizing antibody, isolated from a convalescent patient. Antibody-mediated neutralization occurs via an epitope within the receptor-binding domain of the SARS-CoV-2 Spike protein. SC31 exhibited potent anti-SARS-CoV-2 activities in multiple animal models. In SARS-CoV-2 infected K18-human ACE2 transgenic mice, treatment with SC31 greatly reduced viral loads and attenuated pro-inflammatory responses linked to the severity of COVID-19. Importantly, a comparison of the efficacies of SC31 and its Fc-null LALA variant revealed that the optimal therapeutic efficacy of SC31 requires Fc-mediated effector functions that promote IFNγ-driven anti-viral immune responses, in addition to its neutralization ability. A dose-dependent efficacy of SC31 was observed down to 5mg/kg when administered before viral-induced lung inflammatory responses. In addition, antibody-dependent enhancement was not observed even when infected mice were treated with SC31 at sub-therapeutic doses. In SARS-CoV-2-infected hamsters, SC31 treatment significantly prevented weight loss, reduced viral loads, and attenuated the histopathology of the lungs. In rhesus macaques, the therapeutic potential of SC31 was evidenced through the reduction of viral loads in both upper and lower respiratory tracts to undetectable levels. Together, the results of our preclinical studies demonstrated the therapeutic efficacy of SC31 in three different models and its potential as a COVID-19 therapeutic candidate.

scholarly journals A Multiepitope Fusion Antigen Elicits Neutralizing Antibodies against Enterotoxigenic Escherichia coli and Homologous Bovine Viral Diarrhea VirusIn Vitro

2013 ◽  
Vol 20 (7) ◽  
pp. 1076-1083 ◽  
Author(s):  
Emad A. Hashish ◽  
Chengxian Zhang ◽  
Xiaosai Ruan ◽  
David E. Knudsen ◽  
Christopher C. Chase ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Viral Infection ◽  
Neutralizing Antibodies ◽  
Cell Epitope ◽  
Enterotoxigenic Escherichia Coli ◽  
Bovine Viral Diarrhea ◽  
Content Type ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Fusion Antigen

ABSTRACTDiarrhea is one of the most important bovine diseases. EnterotoxigenicEscherichia coli(ETEC) and bovine viral diarrhea virus (BVDV) are the major causes of diarrhea in calves and cattle. ETEC expressing K99 (F5) fimbriae and heat-stable type Ia (STa) toxin are the leading bacteria causing calf diarrhea, and BVDV causes diarrhea and other clinical illnesses in cattle of all ages. It is reported that maternal immunization with K99 fimbrial antigens provides passive protection to calves against K99 fimbrial ETEC and that BVDV major structural protein E2 elicits antibodies neutralizing against BVDV viral infection. Vaccines inducing anti-K99 and anti-STa immunity would protect calves more effectively against ETEC diarrhea, and those also inducing anti-E2 neutralizing antibodies would protect calves and cattle against diarrhea caused by both ETEC and BVDV. In this study, we used the ETEC K99 major subunit FanC as a backbone, genetically embedded the STa toxoid STaP12Fand the most-antigenic B-cell epitope and T-cell epitope predicted from the BVDV E2 glycoprotein into FanC for the multivalent antigen FanC-STa-E2, and examined immunogenicity of this multivalent antigen to assess vaccine potential against bovine diarrhea. Mice intraperitoneally (i.p.) immunized with this multivalent antigen developed anti-K99, anti-STa, and anti-BVDV antibodies. Moreover, elicited antibodies showed neutralization activities, as they inhibited adherence of K99 fimbrialE. coli, neutralized STa toxin, and prevented homologous BVDV viral infectionin vitro. Results from this study suggest that this multiepitope fusion antigen can potentially be developed as a vaccine for broad protection against bovine diarrhea and that the multiepitope fusion strategy may be generally applied for multivalent vaccine development against heterogeneous pathogens.

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