Source: AUBURN UNIVERSITY submitted to NRP
DNA VACCINATION IN OVO TO PREVENT CHICKEN ANEMIA IN POULTRY
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
ANIMAL HEALTH
Reporting Frequency
Annual
Accession No.
0196741
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2002
Project End Date
Oct 1, 2004
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
AUBURN UNIVERSITY
108 M. WHITE SMITH HALL
AUBURN,AL 36849
Performing Department
PATHOBIOLOGY
Non Technical Summary
Current attenuated chicken anemia vaccines are not absolutely safe since if applied during or shortly prior to the lay onset, the virus can be transmitted vertically and cause disease in the progenies. Since plasmid DNA expression vectors have been reported to successfully immunize chickens and in ovo administration of antigens is a common practice in poultry this project will test the hypothesis that in ovo vaccination with plasmids pVP1 and pVP2 of CAV confer protection to the hatched chickens against CAV infection.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
31532991090100%
Knowledge Area
315 - Animal Welfare/Well-Being and Protection;

Subject Of Investigation
3299 - Poultry, general/other;

Field Of Science
1090 - Immunology;
Goals / Objectives
1. Determine specific antibody responses of chickens hatched from embryos which have been subjected to plasmid VP1 and VP2 dual or single immunization at different days of incubation. 2. Evaluate the specific antibody response of chickens from VP1 and VP2 plasmid vaccinated embryos and homologously boostered after hatch. 3. Evaluate protection of chickens after CAV plasmid in ovo vaccination through challenge with a virulent CAV isolate.
Project Methods
These objectives will be accomplished using specific pathogen free (SPF) embryonated chicken eggs which will be inoculated with plasmids pVP1 and pVP2 previously constructed for DNA immunization against CAV. Embryo immunization will follow different schemes. The induction of immune responses after DNA vaccination will be evaluated by specific antibody detection and challenge of the hatched chickens. Tasks 1.Determine the specific antibody response of 10 and 20 day-old chickens hatched from specific pathogen free (SPF) embryos which have been subjected to plasmid VP1 and VP2 intra-embryo immunization at days 10, 15, and 18 of incubation. 2.Determine the specific antibody response of 10 and 20 day-old SPF chickens hatched from embryos which have been subjected to plasmid VP1 and VP2 double immunization at days 10 and 18 of incubation. 3.Evaluate the specific antibody response of 10 and 20 day-old chickens hatched from VP1 and VP2 plasmid vaccinated SPF embryos at days 10, 15 and 18 of incubation and homologously boostered at day 5 of age. 4.Evaluate protection of chickens after CAV plasmid in ovo vaccination through challenge with a virulent CAV isolate.

Progress 10/01/02 to 10/01/04

Outputs
A plasmid expressing CAV mRNA, resulting in expression of VP1, VP2, and VP3 proteins in the same proportions normally expressed in chicken anemia virus (CAV) infected cells was constructed. The construct was used for immunization attempts in ovo and by the intramuscular route in chickens. Protection possibly induced by the vaccine candidate was evaluated by serology and by challenge with a low passage virulent CAV isolate. Neither hematocrits, weights, viral load as determined by real time PCR,nor histopathologic lesions of the challenged chickens showed significant differences between treated (vaccinated) and non-vaccinated chickens. Associated work performed resulted in the development of a challenge model with CAV, and in the investigation of broiler susceptibility to CAV associated with major histocompatibility complex B genotype.

Impacts
The use of modern technology such as real time PCR to assess viral load as well as the use of histomorphometry has allowed us to describe more accurately the pathological events after oral or intramuscular infection with CAV. This information has been cited in recent reviews of the disease (Miller and Shat, 2004; Avian Dis., 48).

Publications

  • Van Santen, V., F.J. Hoerr, K. Joiner, C. Murray, N. Petrenko, and H. Toro (2004). Pathogenesis of Chicken Anemia Virus: Comparison of the Oral and the Intramuscular Routes of Infection. Avian Diseases 48:494-504.
  • Joiner, K.S., S. J. Ewald, F.J. Hoerr, V.L. van Santen, and H. Toro (2005). Pathogenesis of Chicken Anemia Virus in Broiler Breeders of Different Major Histocompatibility B Complex Genotypes. Avian Pathology (submitted for publication 01/2005).
  • GenBank Registrations van Santen, V. L., Toro, H. and Hoerr, F. J. (2004) 979 bp DNA linear VRL 21-JAN-2004. Chicken anemia virus isolate 03-4876 VP2, VP3, and VP1 genes, partial cds. Accession No: AY513714
  • K. Joiner, V. van Santen, C. Murray, N. Petrenko, F.J. Hoerr, and H. Toro (2004). Chicken Anemia Virus: Oral versus Intramuscular Route of Infection. Proceedings of the 53rd Western Poultry Disease Conference, March 7-9, Sacramento, CA, pp. 39.
  • K. Joiner*, S. Ewald, V. van Santen, F.J. Hoerr, H. Toro (2004). Pathogenesis of Chicken Anemia Virus in Broiler Breeders of Different Major Histocompatibility B Complex Genotypes. North Central Avian Disease Conference, October, Ohio. *PhD student.