* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Adaptive versus innate immune mechanisms in trout responding to
Infection control wikipedia , lookup
Complement system wikipedia , lookup
Anti-nuclear antibody wikipedia , lookup
Childhood immunizations in the United States wikipedia , lookup
Sociality and disease transmission wikipedia , lookup
Cancer immunotherapy wikipedia , lookup
Common cold wikipedia , lookup
Molecular mimicry wikipedia , lookup
Neonatal infection wikipedia , lookup
Polyclonal B cell response wikipedia , lookup
Vaccination policy wikipedia , lookup
Hygiene hypothesis wikipedia , lookup
Immune system wikipedia , lookup
Monoclonal antibody wikipedia , lookup
Henipavirus wikipedia , lookup
Adaptive immune system wikipedia , lookup
Human cytomegalovirus wikipedia , lookup
Psychoneuroimmunology wikipedia , lookup
DNA vaccination wikipedia , lookup
Immunosuppressive drug wikipedia , lookup
Immunocontraception wikipedia , lookup
Herd immunity wikipedia , lookup
Innate immune system wikipedia , lookup
Hepatitis B wikipedia , lookup
Adptive versus innate immune mechanisms in trout responding to rhabdovirus antigens. Niels Lorenzen, Senior Research Scientist, National Veterinary Institute, Technical University of Denmark Early studies with attenuated vaccine preparations demonstrated that it is possible to induce protective immunity to virulent rhabdoviruses such as viral haemorrhagic septicaemia virus (VHSV) and infectious haematopoietic necrosis virus (IHNV) in trout. Little was known about the nature of the protective mechanisms. Cross-protection following inoculation of fish with less pathogenic virus forms suggested that innate nonspecific antiviral activities could be involved. Other data pointed towards adaptive mechanisms. Survivors of infection were immune for several weeks and complement dependent virus neutralizing antibodies could be detected in serum, and although the reactivity of such sera in immunoblotting was inconsistent, some reactivity particularly with the viral surface glycoprotein (G-protein) could be detected. Passive immunization experiments using neutralizing monoclonal antibodies accordingly demonstrated that antibodies against the G-protein were protective and pointed towards this protein as a potential vaccine candidate. However, vaccination using recombinant G protein induced only limited protection and it was not until DNA vaccination technology was introduced that the capacity of the viral G protein to induce protective immunity was clearly demonstrated. Cross protection experiments revealed a twophase scenario concerning protective mechanisms with an early antiviral phase with interferon related innate protection followed by a later and more long lasting period of specific immunity. Temperature is known to affect immune mechanisms in fish and to delay development of adaptive immunity, but interestingly, DNA vaccination protects very well throughout a wide temperature range. Innate protective mechanisms were found to be of much longer duration at 5C compared to 15C, hereby compensating for delayed specific protection. These findings suggest that fish may depend more on innate immune mechanisms as defence against infections at low temperatures. Still, at higher temperatures, innate antiviral mechanisms are also very important as the first line defence against infection of naïve fish. However, a rapid interference with propagation of an infection by innate mechanisms might prevent development of adaptive immunity. Persistence of antigen in sufficient amounts to trigger adaptive mechanisms is therefore a critical parameter in terms of vaccination. DNA vaccination trials with very small rainbow trout fry also induced high level of protection, but the level of specificity, i.e. involvement of innate vs adaptive immune mechanisms, remains to be determined.