Expression of perforin–granzyme pathway genes in the bursa of infectious bursal disease virus-infected chickens

• Published in: Developmental and comparative immunology 2011-05, Vol.35 (5), p.620-627
• Main Authors: Rauf, Abdul, Khatri, Mahesh, Murgia, Maria V., Saif, Yehia M.
• Format: Article
• Language: English
• Subjects: Animals; Apoptosis; Birnaviridae Infections - immunology; Birnaviridae Infections - veterinary; bursa; Bursa of Fabricius; Bursa of Fabricius - metabolism; CD8-positive T-lymphocytes; Cell activation; chickens; Chickens - genetics; Chickens - immunology; Chickens - virology; Cytotoxic T cells; Cytotoxicity; DNA Repair; gamma -Interferon; gene expression; Gene Expression Regulation; genes; Granzyme; Granzymes - genetics; Granzymes - immunology; Helper cells; IBDV; Immunohistochemistry; Infection; infectious bursal disease; Infectious bursal disease virus; interferon-gamma; Interleukin 2; Killer Cells, Natural - cytology; Killer Cells, Natural - immunology; Leukocytes, Mononuclear - cytology; Leukocytes, Mononuclear - metabolism; Lymphocytes B; Lymphocytes T; Lysins; Mobility; Molecular modelling; NAD ADP-ribosyltransferase; pathogenesis; Perforin; Perforin - genetics; Perforin - immunology; Poly(ADP-ribose) polymerase; Poultry Diseases - immunology; proteins; T-Lymphocytes - cytology; T-Lymphocytes - immunology; Virus clearance; viruses
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2011.01.007

Infectious bursal disease (IBD) is an economically important immunosuppressive disease of chickens. The IBD virus (IBDV) actively replicates in B cells and causes severe bursal damage. Generally, T cells are refractory to infection with IBDV but are known to promote virus clearance. However, the mechanisms of T cell mediated viral clearance are not well understood. In this study, we evaluated the molecular mechanisms of cytotoxic T cell responses in the pathogenesis of IBD in chickens. Infection of chickens with IBDV was accompanied by the infiltration of CD4 + and CD8 + T cells in the bursa. There was an upregulation in the gene expression of important cytolytic molecules; perforin (PFN), granzyme-A (Gzm-A), DNA repair and apoptotic proteins; high mobility proteins group (HMG) and poly (ADP-ribose) polymerase (PARP) in the bursa of Fabricius (BF) whereas expression of NK (natural killer) lysin was downregulated. Importantly, PFN producing CD4 + and CD8 + T cells were also detected in the bursa of IBDV-infected chickens by immunohistochemistry. The Th1 cytokines, IL-2 and IFN-γ expression was also strongly upregulated, suggesting the activation of T cells. The findings of this study highlight the mechanisms of IBD pathogenesis and the role of cytotoxic T cells in the clearance of virus-infected cells.