Detection of Avian Antigen-Specific T Cells Induced by Viral Vaccines
Live attenuated viral vaccines are widely used in commercial poultry production, but the development of new effective inactivated/subunit vaccines is needed. Studies of avian antigen-specific T cells are primarily based on analyses ex vivo after activatin
- PDF / 519,498 Bytes
- 12 Pages / 504.57 x 720 pts Page_size
- 92 Downloads / 195 Views
1
Introduction
1.1 Vaccination of Chickens
Poultry is a worldwide important food resource and the production sector continues to grow. Chickens are susceptible to a range of pathogens, some of which are also transmissible to and disease causing in humans, e.g., avian influenza virus. Apart from this, a range of viral diseases is a threat to the animals and causes extensive losses in the chicken production industry. In a historic perspective, the study of the chicken immune system has contributed to our understanding of fundamental immunological principles as reviewed by [1, 2]. Thus, the chicken bursa of Fabricius provided the first evidence of two major lineages of lymphocytes and also understanding of Ig diversification by gene conversion. The chief understanding of MHC-related disease resistance is also derived from studies in chickens. Notably, the research by Louis Pasteur leading to the first attenuated vaccine comprised fowl cholera infection studies in chickens. Later, the first vaccine against a natural occurring cancer agent, Marek’s disease virus, was developed in chickens. Live attenuated viral vaccines are widely used in commercial poultry production, and evidence that intensive vaccination may lead to increased virulence has been reported for some pathogens, e.g., Marek’s disease virus. Indeed, the new viral strains from each successive wave acquired ability to overcome the immunity induced by the previously used vaccine strain [3]. This warns of the need to use more sustainable vaccination strategies that do not drive the pathogen to ever increasing virulence. Thus, it is of interest to develop new effective inactivated/subunit vaccines with capacity to induce long-lasting protecting immunity in commercial chickens.
Sunil Thomas (ed.), Vaccine Design: Methods and Protocols, Volume 2: Vaccines for Veterinary Diseases, Methods in Molecular Biology, vol. 1404, DOI 10.1007/978-1-4939-3389-1_5, © Springer Science+Business Media New York 2016
77
78
Tina Sørensen Dalgaard et al.
1.2 Tools for Assessment of Vaccine-Induced CMI
Cell-mediated immunity (CMI) induced by viral vaccines is important for disease protection. For years, the possibilities to measure the specificity and magnitude of CMI in chickens were hampered due to lack of reagents. Tools were restricted to “classical assays” such as proliferation measured by 3H-thymidine incorporation and CTL activity measured by 51Cr release. These techniques have limitations, e.g., in their suitability for studying MHC-undefined individuals and in their ability to distinguish between different reactive cell subsets. However, rational vaccine design demands establishment of robust T cell assays with the ability to assess phenotype and function of chicken T cell subsets. Few reports exist on developed chicken tetramers [4, 5] and the reagents are not yet commercially available. Thus, studies of chicken antigen-specific T cells are primarily based on analyses ex vivo after activating the cells with recall antigen. There is a particular interest in developi
Data Loading...
