title: Impact of virus load on immunocytological and histopathological parameters during clinical chicken anemia virus (CAV) infection in poultry.
abstract: Chicken anemia virus (CAV) is one the important pathogen affecting commercial poultry sector globally by causing mortality, production losses, immunosuppression, aggravating co-infections and vaccination failures. Here, we describe the effects of CAV load on hematological, histopathological and immunocytochemical alterations in 1-day old infected chicks. The effects of CAV on cytokine expression profiles and generation of virus specific antibody titer were also studied and compared with viral clearance in various tissues. The results clearly confirmed that peak viral load was achieved mainly in lymphoid tissues between 10 and 20 days post infection (dpi), being highest in the blood (log1010.63 ±0.87/ml) and thymus (log1010.29 ±0.94/g) followed by spleen, liver, bone marrow and bursa. The histopathology and immunoflowcytometric analysis indicated specific degeneration of T lymphoid cells in the thymus, spleen and blood at 15 dpi. While the transcript levels of interleukin (IL)-1, IL-2, IL-12 decreased at all dpi, interferon (IFN)-γ increased (3-15 fold) during early stages of infection and the appearance of virus specific antibodies were found to be strongly associated with virus clearance in all the tissues. Our findings support the immunosuppressive nature of CAV and provide the relation between the virus load in the various body tissues and the immunopathological changes during clinical CAV infections.
authors.affiliation: Immunology Section, Division of Veterinary Biotechnology, Indian Veterinary Research Institute (IVRI), Izatnagar, U.P, 243 122, India. Electronic address: mywani27@gmail.com.
authors.forename: Mohd Yaqoob
authors.initials: MY
authors.lastname: Wani
authors.affiliation: Avian Diseases Section, Division of Pathology, Indian Veterinary Research Institute (IVRI), Izatnagar, U.P, 243 122, India.
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Dhama
authors.affiliation: Division of Biological Standardization, Indian Veterinary Research Institute (IVRI), Izatnagar, U.P, 243 122, India.
authors.forename: Yashpal Singh
authors.initials: YS
authors.lastname: Malik
mesh_terms: D000825:Animal Structures / Q000821:virology; D000818:Animals; D000831:Animals, Newborn; D000914:Antibodies, Viral / Q000097:blood; D001769:Blood / Q000821:virology; D017727:Chicken anemia virus / Q000254:growth & development* / Q000302:isolation & purification; D002645:Chickens; D018173:Circoviridae Infections / Q000473:pathology / Q000662:veterinary* / Q000821:virology; D016207:Cytokines / Q000378:metabolism; D007108:Immune Tolerance; D011201:Poultry Diseases / Q000473:pathology* / Q000821:virology; D013997:Time Factors; D019562:Viral Load
chemical_list: D000914:Antibodies, Viral; D016207:Cytokines
keywords: Antibody titre; Chicken infectious anemia; Cytokine; Immunosuppression; Recovery; T lymphocytes; Virus load