Chicken infectious anemia virus: an example of the ultimate host-parasite relationship.
Chicken infectious anemia virus (CIAV) is a resistant and ubiquitous virus of chickens causing disease in young chickens and immunosuppression in all birds. This paper reviews the current knowledge of CIAV with a focus on new findings indicating that immunosuppressive effects have not been fully appreciated, especially as they relate to the development of antigen-specific cytotoxic T cells. A more complete understanding of the immunosuppressive effects of CIAV emphasizes the need for better vaccines, especially for the broiler industry. In addition, a new model is proposed for the control of viral replication in the reproductive tract of specific-pathogen-free chickens, which may be latently infected. This model suggests that virus transcription is controlled by viral enhancer and repressor elements, which are regulated by different hormones. As a consequence, CIAV has a well-adapted relationship with its host, avoiding immune detection, ensuring passage of virus to the next generation, and eliciting limited pathology to the host.
Miller
Myrna M
MM
Unit of Avian Health, Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853, USA.
Schat
K A
KA
D000818:Animals; D017727:Chicken anemia virus / Q000472:pathogenicity*; D002645:Chickens / Q000276:immunology / Q000821:virology*; D018173:Circoviridae Infections / Q000276:immunology / Q000662:veterinary* / Q000821:virology; D004196:Disease Outbreaks / Q000662:veterinary; D007108:Immune Tolerance; D011201:Poultry Diseases / Q000276:immunology / Q000821:virology*; D017735:Virus Latency