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Goo D, Gadde UD, Kim WK, Gay CG, Porta EW, Jones SW, Walker S, Lillehoj HS. Hyperimmune egg yolk antibodies developed against Clostridium perfringens antigens protect against necrotic enteritis. Poult Sci 2023; 102:102841. [PMID: 37480657 PMCID: PMC10393821 DOI: 10.1016/j.psj.2023.102841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/30/2023] [Accepted: 06/01/2023] [Indexed: 07/24/2023] Open
Abstract
Necrotic enteritis (NE) is a widespread infectious disease caused by Clostridium perfringens that inflicts major economic losses on the global poultry industry. Due to regulations on antibiotic use in poultry production, there is an urgent need for alternative strategies to mitigate the negative effects of NE. This paper presents a passive immunization technology that utilizes hyperimmune egg yolk immunoglobulin Y (IgY) specific to the major immunodominant antigens of C. perfringens. Egg yolk IgYs were generated by immunizing hens with 4 different recombinant C. perfringens antigens, and their protective effects against NE were evaluated in commercial broilers. Six different spray-dried egg powders were produced using recombinant C. perfringens antigens: α-toxin, NE B-like toxin (NetB; EB), elongation factor-Tu (ET), pyruvate:ferredoxin oxidoreductase, a mixture of 4 antigens (EM-1), and a nonimmunized control (EC). The challenged groups were either provided with different egg powders at a 1% level or no egg powders (EN). The NE challenge model based on Eimeria maxima and C. perfringens dual infection was used. In Experiments 1 and 2, the EB and ET groups exhibited increased body weight gain (BWG; P < 0.01), decreased NE lesion scores (P < 0.001), and reduced serum NetB levels (P < 0.01) compared to the EN and EC groups. IgY against NetB significantly reduced Leghorn male hepatocellular cytotoxicity in an in vitro test (P < 0.01). In Experiment 3, the protective effect of the IgYs mixture (EM-2) against C. perfringens antigens (NetB and EFTu) and Eimeria antigens (elongation factor-1-alpha: EF1α and Eimeria profilin: 3-1E) was tested. The EM-2 group showed similar body weight, BWG, and feed intake from d 7 to 22 compared to the NC group (P < 0.05). On d 20, the EM-2 group showed comparable intestinal permeability, NE lesion scores, and jejunal NetB and collagen adhesion protein levels to the NC group (P < 0.05). In conclusion, dietary mixture containing antibodies to NetB and EFTu provides protection against experimental NE in chickens through passive immunization.
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Affiliation(s)
- D Goo
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - U D Gadde
- Animal Bioscience and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, MD, USA
| | - W K Kim
- Department of Poultry Science, University of Georgia, Athens, GA, USA
| | - C G Gay
- Office of National Program-Animal Health, Agricultural Research Service, USDA, Beltsville, MD, USA
| | - E W Porta
- Arkion Life Sciences, New Castle, DE, USA
| | - S W Jones
- Arkion Life Sciences, New Castle, DE, USA
| | - S Walker
- Arkion Life Sciences, New Castle, DE, USA
| | - H S Lillehoj
- Animal Bioscience and Biotechnology Laboratory, Beltsville Agricultural Research Center, Agricultural Research Service, USDA, Beltsville, MD, USA.
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2
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Deyra MD, Gay CG, Pizon FP, Gerbaud LG. Determinants of health and cancer: investigating conceptions of children aged 6 to 11. Eur J Public Health 2019. [DOI: 10.1093/eurpub/ckz186.122] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Abstract
Context
Qualitative data on how children and adolescents view their health and its determinants are relatively few at the international level. This research is therefore part of a comprehensive and open-minded approach to better describe how elementary school children perceive the determinants of health and cancer.
Objectives
Our main objective is to map, from a multiphase qualitative protocol, the conceptions and systems of conceptions on the determinants of health and cancers perceived within a 6 to 11 age group.
The secondary objective is to analyze our ability to collect these healthy conceptions from children.
Methodology
Four different tools were used in four schools for 320 students: (1) “photo expression”, (2) “QC (Questions / Certainties)”, (3) “photo narration” and (4) “focus group”. This open and exploratory method, combining the use of photographs and focus groups, provided data on the experiences, stated practices and knowledge of each student. The mobilization of image mediation methods plays an essential ethical role by ensuring the distance between the theme and the child. The informative value of data from qualitative collection tools coupled with a mixed analysis methodology (qualitative and quantitative) allows us to collect dense and efficient data needed to understand the perception of determinants by elementary school students.
Conclusions
This study identifies promising methodological leads thanks to the complementarity of the different phases mobilized. It also provides us with elements of methodological understanding that can contribute to the development of prevention tools as part of the school health education journey.
Key messages
Map, from a multiphase qualitative protocol, the conceptions and systems of conceptions on the determinants of health and cancers perceived within a 6 to 11 age group. Analyze our ability to collect these healthy conceptions from children.
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Affiliation(s)
- M D Deyra
- Université Clermont Auvergne, Institut Pascal, Clermont-Ferrand, France
| | - C G Gay
- Université Clermont Auvergne, Institut Pascal, Clermont-Ferrand, France
| | - F P Pizon
- Université Clermont Auvergne, Institut Pascal, Clermont-Ferrand, France
| | - L G Gerbaud
- Université Clermont Auvergne, Institut Pascal, Clermont-Ferrand, France
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Robinson L, Knight-Jones TJD, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 7 - Pathogenesis and Molecular Biology. Transbound Emerg Dis 2017; 63 Suppl 1:63-71. [PMID: 27320168 DOI: 10.1111/tbed.12520] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Indexed: 11/28/2022]
Abstract
We assessed research knowledge gaps in the fields of FMDV (foot-and-mouth disease virus) pathogenesis and molecular biology by performing a literature review (2011-15) and collecting research updates (2014) from 33 institutes from across the world. Findings were used to identify priority areas for future research. There have been important advances in FMDV pathogenesis; FMDV remains in lymph nodes of many recovered animals that otherwise do not appear persistently infected, even in species previously not associated with the carrier state. Whether virus retention helps maintain host immunity and/or virus survival is not known. Studies of FMDV pathogenesis in wildlife have provided insights into disease epidemiology, in endemic and epidemic settings. Many aspects of FMDV infection and virus entry remain unknown; however, at the cellular level, we know that expression level and availability of integrins (that permit viral entry), rate of clearance of infected cells and strength of anti-viral type I IFN (interferon) response are key determinants of tissue tropism. Extending findings to improved understanding of transmission requires a standardized approach and adoption of natural routes of infection during experimental study. There has been recognition of the importance of autophagosomes for FMDV entry into the cytoplasm following cell surface receptor binding, and that distinct internal cellular membranes are exploited for viral replication and immune evasion. New roles for viral proteins in blocking type I IFN production and downstream signalling have been identified facilitating research in anti-viral therapeutics. We know more about how infection affects cell protein expression, and research into molecular determinants of capsid stability has aided the development of stable vaccines. We have an expanding knowledge of viral and host molecular determinates of virulence and infectiousness, and of how phylogenetics may be used to estimate vaccine match and strain distribution. With ongoing advances, these areas could translate into significantly improved disease control.
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Affiliation(s)
| | | | | | - L L Rodriguez
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY, USA
| | - C G Gay
- Agricultural Research Service, USDA, National Program 103-Animal Health, Beltsville, MD, USA
| | - K J Sumption
- European Commission for the Control of FMD (EuFMD), FAO, Rome, Italy
| | - W Vosloo
- Australian Animal Health Laboratory, CSIRO-Biosecurity Flagship, Geelong, Vic., Australia
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4
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Knight-Jones TJD, Robinson L, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 1 - Overview of Global Status and Research Needs. Transbound Emerg Dis 2017; 63 Suppl 1:3-13. [PMID: 27320162 DOI: 10.1111/tbed.12528] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Indexed: 11/28/2022]
Abstract
The Global Foot-and-mouth disease (FMD) Research Alliance periodically reviews the state of FMD research to assess progress and to identify new priorities. In this supplement we provide an update of global FMD research, comprising (i) this overview paper, which includes background information with key findings, and papers covering (ii) epidemiology, wildlife and economics, (iii) vaccines, (iv) diagnostics, (v) biotherapeutics and disinfectants, (vi) immunology and (vii) pathogenesis and molecular biology. FMD research publications were reviewed (2011-2015) and activity updates were obtained from 33 FMD research institutes from around the world. Although a continual threat, FMD has been effectively controlled in much of the world using existing tools. However, control remains a challenge in most developing countries, where little has been done to understand the ongoing burden of FMD. More research is needed to support control in endemically infected countries, particularly robust field studies. Traditional FMD vaccines have several limitations including short duration and spectrum of protection, cold chain requirements, and the costs and biosecurity risks associated with vaccine production. Significant progress has been made in the development of novel vaccine candidates, particularly in the use of recombinant vaccines and virus-like particles as an alternative to traditional inactivated whole virus vaccines. Continued investment is needed to turn these developments into improved vaccines produced at scale. Increased knowledge of cellular and mucosal immunity would benefit vaccine development, as would further advances in our ability to enhance vaccine capsid stability. Developments in molecular biology and phylogenetics underlie many of the recent advances in FMD research, including improved vaccines and diagnostics, and improved understanding of FMD epidemiology. Tools for genetic analyses continue to become both more powerful and more affordable enabling them to be used to address an ever-expanding range of questions. This rapidly advancing field potentiates many areas of FMD research and should be prioritized.
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Affiliation(s)
| | | | | | - L L Rodriguez
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY, USA
| | - C G Gay
- Agricultural Research Service, USDA, National Program 103-Animal Health, Beltsville, MD, USA
| | - K J Sumption
- European Commission for the Control of FMD (EuFMD), FAO, Rome, Italy
| | - W Vosloo
- Australian Animal Health Laboratory, CSIRO-Biosecurity Flagship, Geelong, Vic., Australia
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Robinson L, Knight-Jones TJD, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 3 - Vaccines. Transbound Emerg Dis 2017; 63 Suppl 1:30-41. [PMID: 27320164 DOI: 10.1111/tbed.12521] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Indexed: 11/28/2022]
Abstract
This study assessed research knowledge gaps in the field of FMDV (foot-and-mouth disease virus) vaccines. The study took the form of a literature review (2011-15) combined with research updates collected in 2014 from 33 institutes from across the world. Findings were used to identify priority areas for future FMD vaccine research. Vaccines play a vital role in FMD control, used both to limit the spread of the virus during epidemics in FMD-free countries and as the mainstay of disease management in endemic regions, particularly where sanitary controls are difficult to apply. Improvements in the performance or cost-effectiveness of FMD vaccines will allow more widespread and efficient disease control. FMD vaccines have changed little in recent decades, typically produced by inactivation of whole virus, the quantity and stability of the intact viral capsids in the final preparation being key for immunogenicity. However, these are exciting times and several promising novel FMD vaccine candidates have recently been developed. This includes the first FMD vaccine licensed for manufacture and use in the USA; this adenovirus-vectored FMD vaccine causes in vivo expression of viral capsids in vaccinated animals. Another promising vaccine candidate comprises stabilized empty FMDV capsids produced in vitro in a baculovirus expression system. Recombinant technologies are also being developed to improve otherwise conventionally produced inactivated vaccines, for example, by creating a chimeric vaccine virus to increase capsid stability and by inserting sequences into the vaccine virus for desired antigen expression. Other important areas of ongoing research include enhanced adjuvants, vaccine quality control procedures and predicting vaccine protection from immune correlates, thus reducing dependency on animal challenge studies. Globally, the degree of independent vaccine evaluation is highly variable, and this is essential for vaccine quality. Previously neglected, the importance of evaluating vaccination programme effectiveness and impact is increasingly being recognized.
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Affiliation(s)
| | | | | | - L L Rodriguez
- Plum Island Animal Disease Center, ARS, USDA, Greenport, NY, USA
| | - C G Gay
- Agricultural Research Service, USDA, National Program 103-Animal Health, Beltsville, MD, USA
| | - K J Sumption
- European Commission for the Control of FMD (EuFMD), FAO, Rome, Italy
| | - W Vosloo
- Australian Animal Health Laboratory, CSIRO-Biosecurity Flagship, Geelong, Vic., Australia
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6
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Abstract
There is a critical need in animal agriculture to develop novel antimicrobials and alternative strategies that will help to reduce the use of antibiotics and address the challenges of antimicrobial resistance. High-throughput gene expression analysis is providing new tools that are enabling the discovery of host-derived antimicrobial peptides. Examples of gene-encoded natural antibiotics that have gained attention include antimicrobial peptides such as human granulysin and its multi-species homolog, namely NK-lysin, which provide a protective response against a broad range of microbes and are a principal component of innate immunity in vertebrates. Both granulysin and NK-lysin are localised in cytolytic granules in natural killer and cytotoxic T lymphocytes. Host-derived NK-lysins that were first described in mammals are also found in avian species, and they have been shown to have antimicrobial activities that could potentially be used to control important poultry pathogens. Morphological alterations observed following chicken NK-lysin binding to Eimeria sporozoites and Escherichia coli membranes indicate damage and disruption of cell membranes, suggesting that NK-lysin kills pathogenic protozoans and bacteria by direct interaction. Genotype analysis revealed that chicken NK-lysin peptides derived from certain alleles were more effective at killing pathogens than those derived from others, which could potentially affect susceptibility to diseases. Although the host-derived antimicrobial peptides described in this paper may not, by themselves, be able to replace the antibiotics currently used in animal production, their use as specific treatments based on their known mechanisms of action is showing promising results.
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Robinson L, Knight-Jones TJD, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 6 - Immunology. Transbound Emerg Dis 2016; 63 Suppl 1:56-62. [DOI: 10.1111/tbed.12518] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/26/2016] [Indexed: 01/26/2023]
Affiliation(s)
| | | | | | - L. L. Rodriguez
- Plum Island Animal Disease Center; ARS; USDA; Greenport NY USA
| | - C. G. Gay
- Agricultural Research Service; USDA; National Program 103-Animal Health; Beltsville MD USA
| | - K. J. Sumption
- European Commission for the Control of FMD (EuFMD); FAO; Rome Italy
| | - W. Vosloo
- Australian Animal Health Laboratory; CSIRO-Biosecurity Flagship; Geelong VIC Australia
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8
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Knight-Jones TJD, Robinson L, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 4 - Diagnostics. Transbound Emerg Dis 2016; 63 Suppl 1:42-8. [DOI: 10.1111/tbed.12523] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/13/2016] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - L. L. Rodriguez
- Plum Island Animal Disease Center; ARS; USDA; Greenport NY USA
| | - C. G. Gay
- Agricultural Research Service; USDA; National Program 103-Animal Health; Beltsville MD USA
| | - K. J. Sumption
- European Commission for the Control of FMD (EuFMD); FAO; Rome Italy
| | - W. Vosloo
- Australian Animal Health Laboratory; CSIRO-Biosecurity Flagship; Geelong VIC Australia
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9
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Robinson L, Knight-Jones TJD, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 5 - Biotherapeutics and Disinfectants. Transbound Emerg Dis 2016; 63 Suppl 1:49-55. [DOI: 10.1111/tbed.12519] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - L. L. Rodriguez
- Plum Island Animal Disease Center; ARS; USDA; Greenport NY USA
| | - C. G. Gay
- National Program 103-Animal Health; Agricultural Research Service; USDA; Beltsville MD USA
| | - K. J. Sumption
- European Commission for the Control of FMD (EuFMD); FAO; Rome Italy
| | - W. Vosloo
- Australian Animal Health Laboratory; CSIRO-Biosecurity Flagship; Geelong Vic. Australia
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10
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Knight-Jones TJD, Robinson L, Charleston B, Rodriguez LL, Gay CG, Sumption KJ, Vosloo W. Global Foot-and-Mouth Disease Research Update and Gap Analysis: 2 - Epidemiology, Wildlife and Economics. Transbound Emerg Dis 2016; 63 Suppl 1:14-29. [DOI: 10.1111/tbed.12522] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Indexed: 11/29/2022]
Affiliation(s)
| | | | | | - L. L. Rodriguez
- Plum Island Animal Disease Center; ARS; USDA; Greenport New York USA
| | - C. G. Gay
- Agricultural Research Service; USDA; National Program 103-Animal Health; Beltsville MD USA
| | - K. J. Sumption
- European Commission for the Control of FMD (EuFMD); FAO; Rome Italy
| | - W. Vosloo
- Australian Animal Health Laboratory; CSIRO-Biosecurity Flagship; Geelong Vic Australia
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Abstract
This review covers the basic biology of the West Nile virus and the host-vector-pathogen interactions that result in significant disease in wild birds, horses and humans. The review describes the basic properties of the virus, cellular infection and the pathogenesis of the disease, and the ecology of virus maintenance, amplification and transmission. Disease epidemiology and risk estimation strategies that are currently in use are also examined, and host immune responses and vaccination practices described. The principles of vector control, exposure control and long-term risks caused by climatic and habitat factors are also included.
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12
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Archibald A, Audonnet JC, Babiuk L, Bishop SC, Gay CG, McKay J, Mallard B, Plastow G, Pinard van der Laan MH, Torremorell M. Animal genomics for animal health report: critical needs, problems to be solved, potential solutions, and a roadmap for moving forward. Dev Biol (Basel) 2008; 132:407-424. [PMID: 18817334 DOI: 10.1159/000317192] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
The first International Symposium on Animal Genomics for Animal Health, held at the World Organisation for Animal Health (OIE) Headquarter, 23-25 October, 2007, Paris, France, assembled more than 250 participants representing research organizations from 26 countries. The symposium included a roundtable discussion on critical needs, challenges and opportunities, and a forward look at the potential applications of animal genomics in animal health research. The aim of the roundtable discussion was to foster a dialogue between scientists working at the cutting edge of animal genomics research and animal health scientists. In an effort to broaden the perspective of the roundtable discussion, the organizers set out four priority areas to advance the use of genome-enabled technologies in animal health research. Contributions were obtained through open discussions and a questionnaire distributed at the start of the symposium. This symposium report provides detailed summaries ofthe outcome ofthe roundtable discussion for each of the four priority areas. For each priority, the problems needing to be solved, according to the views of the participants, are identified, including potential solutions, recommendations, and lastly, concrete steps that could be taken to address these problems. This report serves as a roadmap to steer research priorities in animal genomics research.
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13
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Gay CG, Zuerner R, Bannantine JP, Lillehoj HS, Zhu JJ, Green R, Pastoret PP. Genomics and vaccine development. REV SCI TECH OIE 2007; 26:49-67. [PMID: 17633293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The current explosion in new high-throughput technologies arising from microbial and animal genomics studies is enabling the analysis of the genome, transcriptome, and proteome and offers the opportunity to gain a better understanding of the molecular pathways underlying pathogen biology, the host immune system, and host-pathogen interactions. These new tools can be applied to veterinary pathogens to overcome some of the current hurdles in the discovery of highly effective vaccines for farmed livestock and poultry.
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Affiliation(s)
- C G Gay
- United States Department of Agriculture, Agricultural Research Service, National Program Staff, Animal Production and Protection, Beltsville, MD, USA
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14
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Gay CG, Salt J, Balaski C. Challenges and opportunities in developing and marketing vaccines for OIE List A and emerging animal diseases. Dev Biol (Basel) 2003; 114:243-50. [PMID: 14677694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/27/2023]
Abstract
Veterinary pharmaceutical products generated 14.5 billion U.S. Dollars (USD) in worldwide sales in 2000, with biological products contributing 16.2 percent or 2.3 billion USD. The leading biological products were foot-and-mouth disease (FMD) vaccines, with 284 million USD in sales, representing 26.4 percent of the entire livestock biological business. Despite the potential opportunities for the biologicals industry, non-vaccination policies and undefined control and eradication strategies have deterred the private sector from significant investments in the research and development of vaccines against List A diseases. The primary research focus remains vaccines for infectious diseases that have an impact on current domestic herd health management systems. Changing the vaccine paradigm, investing in new technologies, and creating the future by integrating into key alliances with producers and regulatory authorities will be paramount in protecting our poultry and livestock industries against highly infectious diseases and potential acts of bioterrorism.
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Affiliation(s)
- C G Gay
- Pfizer Inc., Animal Health Group, New York, NY, USA.
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15
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Roth HJ, Gay CG, Espeseth DA. Risk analysis for the importation of veterinary biologicals into the United States of America. REV SCI TECH OIE 1995; 14:1061-72. [PMID: 8639946 DOI: 10.20506/rst.14.4.896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
International trade in veterinary biological products has been restricted by the following factors: a) concerns that contaminated products could result in the introduction of foreign animal disease agents into the importing country b) differences between countries in the technical requirements for product registration. The provisions of the North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT: now the World Trade Organisation [WTO]) require importation decisions to be science-based and transparent. This requires regulatory agencies to implement valid, credible, and science-based risk analysis models for decision-making. The Veterinary Biologics section of the United States Department of Agriculture, Animal and Plant Health Inspection Service, currently uses a formalized risk analysis model to evaluate the safety risks associated with proposals to field test and license new and biotechnology-derived veterinary biological products. This model for evaluating field tests has been modified to evaluate proposals to import veterinary biological products into the United States of America. The authors describe this risk analysis model, which was specifically designed to evaluate the risks of importing veterinary biological products potentially contaminated with foreign animal disease agents.
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Affiliation(s)
- H J Roth
- Animal and Plant Health Inspection Service, United States Department of Agriculture, Riverdale, Maryland 20737-1237, USA
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16
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Affiliation(s)
- C G Gay
- Biotechnology Section of Veterinary Biologics, Biologics, and Environmental Protection, U.S. Department of Agriculture, Hyattsville, MD 20782
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17
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Gay CG, Roth HJ. Confirming the safety characteristics of recombinant vectors used in veterinary medicine: a regulatory perspective. Dev Biol Stand 1994; 82:93-105. [PMID: 7958487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Regulatory guidelines for experimental vaccines should encourage scientists in the biological industry to consider safety at the onset of product development. They should aid scientists to develop the necessary information to confirm conclusively the safety characteristics of the vaccine micro-organism. Moreover, these guidelines should be incorporated into a standardized regulatory process. Veterinary Biologics (VB) provides these guidelines in Summary Information Formats. These Summary Information Formats specify the relevant information to submit with a product licence application for conventional and recombinant vector vaccines. This paper compares two Summary Information Formats to demonstrate that, apart from the construction process, the information required to confirm the safety characteristics of conventional and recombinant vaccines is equivalent. A short discussion on the availability of established safety studies for experimental veterinary vaccines is included.
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Affiliation(s)
- C G Gay
- USDA/APHIS/BBEP, Hyattsville, MD
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18
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Winkles JA, Gay CG. Serum, phorbol ester, and polypeptide mitogens increase class 1 and 2 heparin-binding (acidic and basic fibroblast) growth factor gene expression in human vascular smooth muscle cells. Cell Growth Differ 1991; 2:531-40. [PMID: 1726053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Vascular smooth muscle cell proliferation is regarded as a key early event in the pathogenesis of atherosclerosis. Heparin-binding growth factor (HBGF)-1 and HBGF-2, also referred to as acidic and basic fibroblast growth factor, are potent mitogens for human vascular smooth muscle cells. These cells coexpress HBGF-1 and HBGF-2 and thus represent a vessel wall source for both polypeptides. In this report, we demonstrate that HBGF-1 and HBGF-2 expression is increased when quiescent human smooth muscle cells are treated with fetal bovine serum. The kinetics of HBGF-1 and HBGF-2 mRNA accumulation following serum treatment are distinct. In addition, HBGF-1 transcripts remain elevated for a longer time period; this may reflect the different decay rates of the HBGF-1 and HBGF-2 mRNAs. Serum-inducible HBGF-1 and HBGF-2 mRNA expression does not occur when RNA synthesis is repressed by actinomycin D but can occur in the presence of cycloheximide, an inhibitor of protein synthesis. Immunoprecipitation experiments indicate that serum treatment also increases HBGF-1 and HBGF-2 production. Smooth muscle cells treated with phorbol 12-myristate 13-acetate or certain combinations of polypeptide growth factors also express increased levels of HBGF-1 and HBGF-2 transcripts. Potential sources for these growth factors in vivo include platelets, macrophages, and T lymphocytes; thus, smooth muscle cells located at sites of vascular injury or inflammation may express elevated levels of HBGF-1 and HBGF-2.
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Affiliation(s)
- J A Winkles
- Laboratory of Molecular Biology, American Red Cross, Rockville, Maryland 20855
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Abstract
Platelet-derived growth factor (PDGF) may be an important regulator of vascular smooth muscle cell (SMC) replication and migration in vivo. Platelets, macrophages, endothelial cells, and SMC are all potential sources of PDGF in the vessel wall. In this study, we have examined the regulation of PDGF gene expression using human SMC cultured in vitro. These cells express transcripts encoding the PDGF A-chain, but not the B-chain. The addition of serum, phorbol ester, acidic fibroblast growth factor, transforming growth factor-beta, or tumor necrosis factor-alpha to serum-starved SMC increased PDGF A-chain mRNA levels. The cytokines interleukin-1 and -6 had no detectable effect. These results indicate that SMC present at sites of injury or inflammation may express elevated levels of PDGF-AA, which could act locally in an autocrine or paracrine manner.
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Affiliation(s)
- J A Winkles
- Laboratory of Molecular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland 20855
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20
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Gay CG, Winkles JA. The half-lives of platelet-derived growth factor A- and B-chain mRNAs are similar in endothelial cells and unaffected by heparin-binding growth factor-1 or cycloheximide. J Cell Physiol 1991; 147:121-7. [PMID: 1709940 DOI: 10.1002/jcp.1041470116] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Platelet-derived growth factor (PDGF) is mitogenic and chemotactic for vascular smooth muscle cells cultured in vitro, and, thus, may play a role in the smooth muscle cell proliferation and migration that occurs during atherosclerotic lesion development. Two related PDGF polypeptides, designated as the A and B chains, form functionally active PDGF-AA, AB, or BB dimers. The PDGF A- and B-chain genes are both transcribed in human umbilical vein endothelial (HUVE) cells and their expression is regulated by cytokines, growth factors, endotoxin, and phorbol ester. We reported previously that the angiogenic polypeptide heparin-binding growth factor (HBGF)-1 induces PDGF A-chain gene expression, but does not affect PDGF B-chain gene expression. In this study, we determined whether mRNA stabilization contributed to this induction by measuring the half-life of PDGF A-chain mRNA in quiescent, HBGF-1-stimulated, and proliferating HUVE cells. PDGF A-chain mRNA levels increase when quiescent HUVE cells are treated with the protein synthesis inhibitor cycloheximide; therefore, the effect of cycloheximide on PDGF A-chain mRNA decay was also investigated. The half-life of PDGF A-chain transcripts in quiescent cells was approximately 2.4 h and neither HBGF-1 nor cycloheximide significantly altered this decay rate. We also estimated the half-life of PDGF B-chain mRNA under the three different growth conditions and in the absence or presence of cycloheximide. The half-life in quiescent cells was approximately 1.8 h and was unaffected by HBGF-1 or protein synthesis inhibition. Therefore, the PDGF mRNAs have similar decay rates in HUVE cells, even though the 3' untranslated region of B-chain transcripts, but not A-chain transcripts, contains AU-rich sequence motifs postulated to confer rapid turnover in vivo.
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Affiliation(s)
- C G Gay
- Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland 20855
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21
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Abstract
The angiogenic polypeptide heparin-binding growth factor 2 (HBGF-2), or basic fibroblast growth factor, is a mitogen for vascular smooth muscle cells in vitro and in vivo. Smooth muscle cells also synthesize HBGF-2; thus, it may stimulate their proliferation in vivo by both autocrine and paracrine mechanisms. We report here that HBGF-2 gene expression in human saphenous vein smooth muscle cells is induced by interleukin (IL)-1 alpha and IL-1 beta, inflammatory cytokines produced by many cell types in response to a variety of signals. Maximal HBGF-2 mRNA levels are detected 2-4 hr after IL-1 treatment; induction may require de novo protein synthesis and does not occur if transcription is inhibited. Immunoprecipitation analysis indicates that IL-1-stimulated cells also express an increased amount of HBGF-2 protein. Interferon gamma and glucocorticoids, inhibitors of smooth muscle cell proliferation in vitro and in vivo, suppress the induction of HBGF-2 expression by IL-1. These results imply that cytokines released at sites of vascular injury or inflammation may regulate HBGF-2 production by smooth muscle cells. Increased HBGF-2 levels within the vessel wall could play a role in both the smooth muscle cell proliferation and the neovascularization associated with the development of atherosclerotic lesions.
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Affiliation(s)
- C G Gay
- Laboratory of Molecular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, MD 20855
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22
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Gay CG, Winkles JA. Heparin-binding growth factor-1 stimulation of human endothelial cells induces platelet-derived growth factor A-chain gene expression. J Biol Chem 1990; 265:3284-92. [PMID: 1689299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Heparin-binding growth factor-1 (HBGF-1), also known as acidic fibroblast growth factor, is a potent mitogen for a variety of cell types including vascular endothelial and smooth muscle cells. Studies using murine 3T3 fibroblasts have shown that HBGF-1 induces numerous cellular responses such as the tyrosine phosphorylation of specific polypeptides and the increased expression of actin mRNA. Here we report that the addition of HBGF-1 to quiescent human umbilical vein endothelial cells increases the level of platelet-derived growth factor (PDGF) A-chain mRNA but not PDGF B-chain mRNA. In contrast, factors that inhibit endothelial cell proliferation such as phorbol myristate acetate and the cytokines interleukin-1, interleukin-6, and tumor necrosis factor-alpha increase both PDGF A-chain and B-chain mRNA levels. HBGF-1 induction of PDGF A-chain mRNA expression occurs in the presence of the protein synthesis inhibitor cycloheximide and thus does not require de novo protein synthesis. HBGF-1 also increases c-fos, c-jun, and c-myc mRNA levels; in the presence of cycloheximide, PDGF A-chain and protooncogene mRNA accumulation kinetics are similar. Nuclear run-on experiments indicate that the transcription rate of the PDGF A-chain gene transiently increases after HBGF-1 addition. Immunoprecipitation analysis using PDGF A-chain-specific antibodies indicates that HBGF-1-stimulated cells synthesize and secrete an increased amount of PDGF relative to unstimulated cells. If HBGF-1 can regulate PDGF expression by vascular endothelial cells in vivo, then HBGF-1 availability would be an important component of smooth muscle cell growth control. For example, HBGF-1 within the vessel wall would promote smooth muscle cell proliferation by (a) direct interaction with smooth muscle cell HBGF-1 receptors, and (b) increasing the amount of endothelial cell-derived PDGF available for binding to smooth muscle cell PDGF receptors.
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Affiliation(s)
- C G Gay
- Laboratory of Molecular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland 20855
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Joseph PL, Espeseth DA, Shibley GP, Gay CG. Environmental considerations for field testing and licensing of live genetically-engineered veterinary biologics. REV SCI TECH OIE 1988; 7:285-300. [PMID: 32370414 DOI: 10.20506/rst.7.2.350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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