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Kubo N, Park CH, Inoue S, Hatta H. Comparison of Anti-rabies Virus Nucleoprotein IgY Prepared by DNA Immunization and Protein Immunization. J Poult Sci 2023; 60:2023014. [PMID: 37334105 PMCID: PMC10270695 DOI: 10.2141/jpsa.2023014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Accepted: 04/19/2023] [Indexed: 06/20/2023] Open
Abstract
Immunization of egg-laying hens with viral antigens efficiently produces large amounts of virus-specific IgY antibodies from egg yolks. A supply of practical and economical antibodies against the rabies virus is being desired worldwide. We immunized hens with the antigen gene DNA of the rabies virus, purified specific IgY antibodies from the egg yolk, and characterized the immuno-protein chemistry for use as a diagnosis. To prepare specific IgY antibodies against rabies virus nucleoprotein (RV-N) by DNA immunization, laying hens were pre-injected with λ-carrageenan or Freund's complete adjuvant to increase local immune activity (pre-immune stimulation), and then immunized with RV-N recombinant plasmid DNA. RV-N-specific IgY antibodies were prepared from egg yolks of immunized hens. For comparison, conventional protein antigen immunization was also used to induce the production of RV-N-specific IgY antibodies. Laying hens were immunized with an RV-N protein antigen and RV-N-specific IgY was purified from egg yolks. The binding activity against RV-N antigens was examined using IgY samples prepared by DNA (with pre-immune stimulation) and protein immunization. Immunohistochemical staining showed that IgY antibodies prepared by protein immunization strongly detected viral antigens in the brain sections of dogs infected with the virus, whereas IgY antibodies prepared by DNA immunization did not. Enzyme-linked immunosorbent assay was performed using a commercially available rabies vaccine (inactivated virus) treated with 10% formalin and heating (60°C, 30 min and 90°C, 5 min). IgY prepared by DNA immunization had weaker reactivity with denatured antigens and lower antigen concentrations than IgY prepared by protein immunization. These results suggest that it is necessary to develop a DNA immunization method for inducing IgY antibodies against the rabies virus that strongly bind to native and denatured antigens to prepare specific IgYs that can be used for antigen detection in clinical tests.
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Affiliation(s)
- Nanase Kubo
- Egg & Poultry Research Center, NBL Co., Ltd., Kyoto
605-8501, Japan
- Kyoto Women’s University, Kyoto 605-8501, Japan
| | - Chun-ho Park
- Department of Veterinary Pathology, School of Veterinary
Medicine, Kitasato University, Aomori 0341-8628, Japan
| | - Satoshi Inoue
- Department of Veterinary Pathology, School of Veterinary
Medicine, Kitasato University, Aomori 0341-8628, Japan
- Laboratory of Transmission Control of Zoonosis, Department
of Veterinary Science National Institute of Infectious Diseases, Tokyo 162-8640,
Japan
| | - Hajime Hatta
- Egg & Poultry Research Center, NBL Co., Ltd., Kyoto
605-8501, Japan
- Kyoto Women’s University, Kyoto 605-8501, Japan
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Preparation of Anti-Rabies Virus N Protein IgYs by DNA Immunization of Hens Using Different Types of Adjuvants. J Poult Sci 2022; 59:191-196. [PMID: 35528385 PMCID: PMC9039140 DOI: 10.2141/jpsa.0210053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 06/17/2021] [Indexed: 11/29/2022] Open
Abstract
DNA immunization has been used to study vaccination methods and for production of specific antibodies. The present study aimed to apply DNA immunization to prepare specific IgYs, which react against rabies virus N protein (RV-N) and can be used to research and diagnose rabies virus. The DNA sequence of RV-N was ligated into a pcDNA 3.1 plasmid for constructing pcDNA-N. Eight hens were divided into four groups. Group 1 comprised the control group (non-immunized). In Groups 2, 3, and 4, hens were injected intramuscularly with pcDNA-N (400 µg/hen). Eight injections were administered every other week. From the 4th week, an adjuvant was injected in addition to pcDNA-N. Freund's complete adjuvant (FCA) and λ-carrageenan were administered to Groups 3 and 4, respectively. Eggs were collected daily, and the specific antibody activities of egg yolks were measured by ELISA. IgYs were purified from pooled egg yolks at 16–19 weeks post-administration in each group. The detection sensitivities of the RV-N were compared using purified IgY as the primary antibody for ELISA, dot blotting, and western blotting. Egg yolks from one of the two hens in Group 2 (pcDNA-N alone) and all hens in Groups 3 (pcDNA-N + FCA) and 4 (pcDNA-N + λCarra) had increased ELISA values. The combined use of λ-carrageen in DNA immunization resulted in an adjuvant effect comparable to that of FCA. Each purified specific IgY detected RV-N in the ELISA, western blotting, and dot blotting; however, the detection sensitivity differed. Higher detection sensitivity of the +λCarra IgY was observed by ELISA, whereas there was higher detection sensitivity of +FCA IgY in western blotting and dot blotting. In summary, anti-rabies virus N protein IgY was prepared through DNA immunization of hens using FCA or λ-carrageenan as adjuvants and can be used as a primary antibody to detect rabies viruses.
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Stable Recombinant-Gene Expression from a Ligilactobacillus Live Bacterial Vector via Chromosomal Integration. Appl Environ Microbiol 2021; 87:AEM.00392-21. [PMID: 33741626 DOI: 10.1128/aem.00392-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 03/08/2021] [Indexed: 01/08/2023] Open
Abstract
Disease control in animal production systems requires constant vigilance. Historically, the application of in-feed antibiotics to control bacteria and improve performance has been a much-used approach to maintain animal health and welfare. However, the widespread use of in-feed antibiotics is thought to increase the risk of antibiotic resistance developing. Alternative methods to control disease and maintain productivity need to be developed. Live vaccination is useful in preventing colonization of mucosa-dwelling pathogens by inducing a mucosal immune response. Native poultry isolate Ligilactobacillus agilis La3 (previously Lactobacillus agilis) has been identified as a candidate for use as a live vector to deliver therapeutic proteins such as bacteriocins, phage endolysins, or vaccine antigens to the gastrointestinal tract of chickens. In this study, the complete genome sequence of L. agilis La3 was determined and transcriptome analysis was undertaken to identify highly expressed genes. Predicted promoter regions and ribosomal binding sites from constitutively expressed genes were used to construct recombinant protein expression cassettes. A series of double-crossover shuttle plasmids were constructed to facilitate rapid selectable integration of expression cassettes into the L agilis La3 chromosome via homologous recombination. Inserts showed 100% stable integration over 100 generations without selection. A positive relationship was found between protein expression levels and the predicted strength of the promoters. Using this system, stable chromosomal expression of a Clostridium perfringens antigen, rNetB, was demonstrated without selection. Finally, two recombinant strains, L agilis La3::P eft -rnetB and L agilis La3::P cwah -rnetB, were constructed and characterized, and they showed potential for future application as live vaccines in chickens.IMPORTANCE Therapeutic proteins such as antigens can be used to prevent infectious diseases in poultry. However, traditional vaccine delivery by intramuscular or subcutaneous injection generally has not proven effective for mucosa-dwelling microorganisms that live within the gastrointestinal tract. Utilizing live bacteria to deliver vaccine antigens directly to the gut immune system can overcome some of the limitations of conventional vaccination. In this work, Ligilactobacillus agilis La3, an especially effective gut colonizer, has been analyzed and engineered with modular and stable expression systems to produce recombinant proteins. To demonstrate the effectiveness of the system, expression of a vaccine antigen from poultry pathogen Clostridium perfringens was monitored over 100 generations without selection and found to be completely stable. This study demonstrates the development of genetic tools and novel constitutive expression systems and further development of L. agilis La3 as a live delivery vehicle for recombinant proteins.
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Beirão BCB, Ingberman M, Mesa D, Salles GBC, Muniz EC, Caron LF. Effects of aroA deleted E. coli vaccine on intestinal microbiota and mucosal immunity. Comp Immunol Microbiol Infect Dis 2021; 75:101612. [PMID: 33477024 DOI: 10.1016/j.cimid.2021.101612] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 01/10/2021] [Accepted: 01/10/2021] [Indexed: 01/16/2023]
Abstract
E. coli infection of broilers can result in systemic diseases and productivity losses. Use of antimicrobials against this condition is common but other approaches, such as vaccination, are gaining ground. Anecdotal field reports indicate that intestinal health is improved unspecifically following E. coli live vaccination. We hypothesized that the intestine may be an important site for the functionality of the vaccine. Vaccine effects on the intestine were assessed. Spray vaccination induced marked alterations of the caecum microbiota of broilers within 3 days, and this effect gradually waned. However, T cell activation occurred in the spleen, but not in caecal tonsils, and anti-E. coli IgA was concentrated in the respiratory mucosae. Accordingly, IL-6 mRNA was produced in the lungs following immunization. Overall, these data are an initial indication that any vaccine-induced effects on the intestine are greatly associated with the microbiota. However, immunity conferred by vaccination is not primarily induced in gut-associated lymphoid tissues.
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Affiliation(s)
- Breno C B Beirão
- Imunova Análises Biológicas, Setor de Ciências Biológicas UFPR, Curitiba, PR, 81531-980, Brazil; Universidade Federal do Paraná, Setor de Ciências Biológicas UFPR, Curitiba, 81531-980, Brazil.
| | - Max Ingberman
- Imunova Análises Biológicas, Setor de Ciências Biológicas UFPR, Curitiba, PR, 81531-980, Brazil
| | - Dany Mesa
- Universidade Federal do Paraná, Setor de Ciências Biológicas UFPR, Curitiba, 81531-980, Brazil
| | - Gleidson B C Salles
- Zoetis Indústria de Produtos Veterinários Ltda, São Paulo, SP, 04709-111, Brazil
| | - Eduardo C Muniz
- Zoetis Indústria de Produtos Veterinários Ltda, São Paulo, SP, 04709-111, Brazil
| | - Luiz Felipe Caron
- Universidade Federal do Paraná, Setor de Ciências Biológicas UFPR, Curitiba, 81531-980, Brazil
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The Construction and Immunoadjuvant Activities of the Oral Interleukin-17B Expressed by Lactobacillus plantarum NC8 Strain in the Infectious Bronchitis Virus Vaccination of Chickens. Vaccines (Basel) 2020; 8:vaccines8020282. [PMID: 32517220 PMCID: PMC7350006 DOI: 10.3390/vaccines8020282] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 06/01/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
Interleukin-17B (IL-17B) is a protective cytokine of the IL-17 family and plays an essential role in the regulation of mucosal inflammation. However, little is known about the role of IL-17B in the control of viral infections. In this study, a recombinant Lactobacillus plantarum, designated as NC8-ChIL17B, was constructed to express the chicken IL-17B (ChIL-17B) gene. The recombinant ChIL17B (rChIL17B) protein was about 14 kDa and was anchored to the surface of NC8 cells. In vitro, it was found that the rChIL17B protein inhibited the proliferation of the infectious bronchitis virus (IBV) through activation of nuclear factor kappa B (NF-κB) and the JAK (Janus kinase)-STAT (signal transducers and activators of transcription) signaling. Moreover, to evaluate the immunoadjuvant activities of NC8-ChIL17B, 40 three-day-old specific pathogen-free (SPF) chickens were divided into four groups. Three groups were orally vaccinated with fresh NC8, NC8-ChIL17B, and phosphate buffered saline (PBS), along with the infectious bronchitis virus vaccine, and the other group was the PBS-negative control. The results of the IBV-specific antibody titer and the concentration of the cytokines IL-2, IL-4, IL-6, and interferon gamma (IFN-γ) in sera, as well as the concentration of secretory immunoglobulin A (sIgA) in the tracheal and small intestinal mucosa, the number of cluster of differentiation 4 positive (CD4+) and cluster of differentiation 8 positive (CD8+) T cells in the blood, and the expression of immune-related genes all indicated that NC8-ChIL17B efficiently enhanced the humoral and cellular immune responses to IBV vaccine. Moreover, the viral loads in the NC8-ChIL17B- and IBV-vaccinated group were significantly lower than in the control groups, suggesting a significant promotion of the immunoprotection of IBV vaccination against the virulent IBV strain. Therefore, ChIL-17B is a promising, effective adjuvant candidate for chicken virus vaccines.
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Abstract
Robust and sustainable development of poultry industry requires prevention of deadly infectious diseases. Vigorous vaccination of the birds is a routine practice; however, the live and inactivated vaccines that are used have inherent disadvantages. New-generation vaccines such as DNA vaccines offer several advantages over conventional vaccines. DNA vaccines, which encode an antigen of interest or multiple antigens in the target host, are stable, easy to produce and administer, do not require cold chain maintenance, and are not affected by the maternal antibodies. In addition, DNA vaccines can also be administered in ovo, and thus, mass vaccination and early induction of immune response can effectively be achieved. In this chapter, we focus on the development of DNA vaccines against important infectious viral as well as parasitic diseases of poultry.
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Affiliation(s)
- Shishir Kumar Gupta
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122, India.
| | - Sohini Dey
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122, India
| | - Madhan Mohan Chellappa
- Division of Veterinary Biotechnology, Indian Veterinary Research Institute, Izatnagar, Bareilly, 243122, India
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Prospects and challenges of using chicken cytokines in disease prevention. Vaccine 2012; 30:7165-73. [DOI: 10.1016/j.vaccine.2012.10.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/26/2012] [Accepted: 10/07/2012] [Indexed: 12/12/2022]
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Niederstadt L, Hohn O, Dorner BG, Schade R, Bannert N. Stimulation of IgY responses in gene gun immunized laying hens by combined administration of vector DNA coding for the target antigen Botulinum toxin A1 and for avian cytokine adjuvants. J Immunol Methods 2012; 382:58-67. [PMID: 22580181 DOI: 10.1016/j.jim.2012.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 04/26/2012] [Accepted: 05/01/2012] [Indexed: 01/13/2023]
Abstract
DNA immunization is a convenient and effective way of inducing a specific antibody response. In mammals, co-administration of vectors encoding immunostimulatory cytokines can enhance the humoral response resulting in elevated antibody titers. We therefore set out to investigate the effect using avian interleukin 1β (IL-1β) and avian interleukin 6 (IL-6) as genetic adjuvants when immunizing laying hens. A BoNT A1 holotoxoid DNA immunogen carrying two inactivating mutations was evaluated for its ability to induce a specific and sustained IgY antibody response. Both the holotoxoid and the cytokine sequences were codon-optimized. In vitro, the proteins were efficiently expressed in transfected HEK 293T cells and the cytokines were secreted into the culture supernatants. Whereas eggs from hens immunized via gene gun using a prime boost strategy showed no differences in their total IgY content, the specific αBoNT A1 response was slightly elevated up to 1.4× by the IL-1β adjuvant vector and increased by 3.8× by the IL-6 vector. Finally, although hens receiving the IL-1β adjuvant had laying capacities above the average, hens receiving the IL-6 adjuvant experienced laying problems.
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Affiliation(s)
- Lars Niederstadt
- FU-Berlin, Fachbereich Biologie, Chemie, Pharmazie, Berlin, Germany
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Su BS, Yin HS, Chiu HH, Hung LH, Huang JP, Shien JH, Lee LH. Immunoadjuvant activities of a recombinant chicken IL-12 in chickens vaccinated with Newcastle disease virus recombinant HN protein. Vet Microbiol 2011; 151:220-8. [DOI: 10.1016/j.vetmic.2011.02.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2010] [Revised: 02/14/2011] [Accepted: 02/17/2011] [Indexed: 11/26/2022]
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Hiszczyńska-Sawicka E, Akhtar M, Kay GW, Holec-Gąsior L, Bickerstaffe R, Kur J, Stankiewicz M. The immune responses of sheep after DNA immunization with, Toxoplasma gondii MAG1 antigen—with and without co-expression of ovine interleukin 6. Vet Immunol Immunopathol 2010; 136:324-9. [DOI: 10.1016/j.vetimm.2010.03.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Revised: 03/16/2010] [Accepted: 03/22/2010] [Indexed: 01/24/2023]
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Nikbakht Brujeni G, Jalali SAH, Koohi MK. Development of DNA-designed avian IgY antibodies for quantitative determination of bovine interferon-gamma. Appl Biochem Biotechnol 2010; 163:338-45. [PMID: 20652441 DOI: 10.1007/s12010-010-9042-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2010] [Accepted: 07/12/2010] [Indexed: 02/08/2023]
Abstract
Interferon-gamma (IFN-γ), a cytokine produced by sensitized T lymphocytes, is one of the key elements in defining T helper 1 lymphocyte immune responses. Quantitative evaluation of IFN-γ expression could provide an important analytical tool for measurement of cell-mediated immunity and investigating immune responses to infectious diseases. Method of DNA-designed avian IgY antibodies was used for production of monospecific polyclonal antibodies that allows quantification of the recombinant bovine IFN-γ protein. IFN-γ cDNA was subcloned and expressed in mammalian expression plasmid (pcDNA3.1(+)) under the control of the human cytomegalovirus promoter. Chickens were immunized by plasmid DNA, and egg yolk antibodies extracted from eggs were collected after immunization. IgY-specific antibodies were evaluated by an antigen capture enzyme-linked immunosorbent assay (ELISA) using recombinant IFN-γ. Based on the results, developed bovine IFN-γ capture ELISA could detect up to 1 ng/ml of IFN-γ by 64-fold diluted IgY. Monospecific anti-bovine IFN-γ antibodies generated in chickens are useful for quantifying different concentrations of recombinant bovine IFN-γ, which is expressed in cell culture.
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Affiliation(s)
- Gholamreza Nikbakht Brujeni
- Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran,
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DNA vaccines and their applications in veterinary practice: current perspectives. Vet Res Commun 2008; 32:341-56. [PMID: 18425596 PMCID: PMC7089108 DOI: 10.1007/s11259-008-9040-3] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 03/04/2008] [Indexed: 01/30/2023]
Abstract
Inoculation of plasmid DNA, encoding an immunogenic protein gene of an infectious agent, stands out as a novel approach for developing new generation vaccines for prevention of infectious diseases of animals. The potential of DNA vaccines to act in presence of maternal antibodies, its stability and cost effectiveness and the non-requirement of cold chain have heightened the prospects. Even though great strides have been made in nucleic acid vaccination, still there are many areas that need further research for its wholesome practical implementation. Major areas of concern are vaccine delivery, designing of suitable vectors and cytotoxic T cell responses. Also, the induction of immune responses by DNA vaccines is inconclusive due to the lack of knowledge regarding the concentration of the protein expressed in vivo. Alternative delivery systems having higher transfection efficiency and the use of cytokines, as immunomodulators, needs to be further explored. Recently, efforts are being made to modulate and prolong the active life of dendritic cells, in order to make antigen presentation a more efficacious one. For combating diseases like acquired immunodeficiency syndrome (AIDS), influenza, malaria and tuberculosis in humans; and foot and mouth disease, Aujesky’s disease, swine fever, rabies, canine distemper and brucellosis in animals, DNA vaccine clinical trials are underway. This review highlights the salient features of DNA vaccines, and measures to enhance their efficacy so as to devise an effective and novel vaccination strategy against animal diseases.
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Lévesque S, Martinez G, Fairbrother JM. Improvement of Adjuvant Systems to Obtain a Cost-Effective Production of High Levels of Specific IgY. Poult Sci 2007; 86:630-5. [PMID: 17369532 DOI: 10.1093/ps/86.4.630] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Incomplete Freund's adjuvant (IFA) is used as standard adjuvant for the production of specific antibodies. In this study, we evaluated the ability of supplementation of IFA with 1alpha,25-dihydroxyvitamin D(3) [1alpha,25(OH)(2)D(3)] or C-phosphate-guanosine-oligodeoxynucleotide (CpG-ODN) to enhance the quantity of specific IgY found in the eggs of hyperimmunized laying hens. In this comparative study, the fimbrial adhesin F4 of porcine enterotoxigenic Escherichia coli was used as prototype immunogen. Hens of 3 groups received by i.m. injection 20 microg of purified F4 adhesin emulsified with 1 of the following adjuvants: 0.5 mL of IFA alone (F4-IFA group), 0.5 mL of IFA supplemented with 285.6 ng of 1alpha,25(OH)(2)D(3) (F4-IFA-D(3) group), or 0.5 mL of IFA supplemented with 10 microg of CpG-ODN (F4-IFA-CpG group). Hens of 2 control groups received PBS or purified F4 alone. Immunization was repeated after 2 and 5 or 7 wk. Eggs were collected at 3- to 4-d intervals from preimmunization to d 79, and whole eggs were tested to measure the quantity of anti-F4 IgY by a standardized indirect ELISA. The quantity of specific anti-F4 IgY present in eggs from immunized hens of the F4-IFA group increased from d 13 to 79, corresponding to the end of the experiment. The values for this group at each time were considered as 100%. Results obtained for the other adjuvants were expressed in relation to this reference method. Supplementation of IFA with 1alpha,25(OH)(2)D(3) did not result in any enhancement of the quantity of anti-F4 IgY present in the eggs. On the other hand, supplementation of IFA with CpG-ODN resulted in an enhancement of yield up to 942% of the F4-specific antibody response. Moreover, the use of CpG-ODN is a cost-effective and ethical refinement for the production of specific antibodies, permitting a reduction in the number of immunizations needed. In conclusion, this study provides strong evidence for the use of IFA supplemented with CpG-ODN rather than IFA alone for the production of high levels of specific antibody in laying hens.
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Affiliation(s)
- S Lévesque
- Reference Laboratory for Escherichia coli, Groupe de Recherche sur les Maladies Infectieuses du Porc, Faculté de Médecine Vétérinaire, Université de Montréal, Quebec, Canada
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