|Kaiser, Peter - INS. AN. HLTH. U.K.|
Submitted to: American Association of Avian Pathologist
Publication Type: Proceedings
Publication Acceptance Date: July 16, 2002
Publication Date: N/A
Interpretive Summary: Cytokines are chemical substances produced by all types of cells in the body. The cells "talk" to each other using these substances. Probably the most important cytokines are those involved with the immune system that help an animal fight infections. The first part of this review describes some cytokines that have been identified in chickens and what we have learned about the role they play in protecting chickens from infections. The second part of the review describes how scientists have been able to make some of these cytokines in test tubes and then what happens to the chickens when they are injected into the birds. The third part of the review describes how future experiments should be planned that takes advantage of this information so that we can give cytokines to baby chicks when they hatch to protect them from all sorts of diseases. This information is important to the veterinarians that treat chickens and turkeys because the use of certain types of drugs to treat diseases in poultry is becoming more controversial.
Technical Abstract: Cytokines are soluble, low molecular weight polypeptides and glycopeptides produced by a broad range of immune and nonimmune cell types that have suppressive or enhancive effects on multiple cellular mechanisms. A complex network of cytokines controls both inflammatory responses and specific immune responses to invasive microbes, which were evolved to protect the host from pathogens. As regulators of the initiation and maintenance of host defenses, cytokines ultimately determine the type of response generated and the effector mechanisms generated to mediate resistance. As effector molecules, cytokines are produced transiently and locally to control the amplitude and duration of the response. Likewise, excessive or insufficient production of a cytokine or cytokines may contribute significantly to the pathophysiology of disease. Therefore, cytokines play pivotal, but paradoxical roles in both in the regulation of inflammation and immunity. This review will focus the use of exogenous cytokines against infectious agents in poultry medicine for: (a) their use as adjuvants for vaccines and (b) their ability to stimulate the ontogeny and activation of neonatal host defenses. New evidence is emerging which proposes an intimate interactive relationship between the innate and acquired systems that will have profound effects on vaccine development in the future. The innate immune response has bee found to be directly involved in the detection of infecting organisms. Recognition of molecular patterns unique to the invading pathogens allows the innate system, through the production of cytokines, chemokines, and co-stimulatory molecules to guide the selection of antigen by the T- and B-lymphocytes (acquired immune system) and the secretion of effector cytokines that promote an appropriate host response to the infection. Future research and development could concentrate on the identification and cloning the gene(s) of chicken cytokines produced by the innate response that regulate the acquired immune response. These cytokines could be developed for use as natural adjuvants in poultry vaccines and/or modulators of the host immune response.