The bursa of Fabricius (BF) is a central humoral immune organ unique to birds. Four bursal peptides (BP-I, BP-II, BP-III, and BP-IV) have been isolated and identified from the BF. In this study, the immunoadjuvant activities of BPs I to IV were examined in mice immunized with H9N2 avian influenza virus (AIV) vaccine. The results suggested that BP-I effectively enhanced cell-mediated immune responses, increased the secretion of Th1 (interferon gamma)- and Th2 (interleukin-4)-type cytokines, and induced an improved cytotoxic T-lymphocyte (CTL) response to the H9N2 virus. BP-II mainly elevated specific antibody production, especially neutralizing antibodies, and increased Th1- and Th2-type cytokine secretion. BP-III had no significant effect on antibody production or cell-mediated immune responses compared to those in the control group. A strong immune response at both the humoral and cellular levels was induced by BP-IV. Furthermore, a virus challenge experiment followed by H&E staining revealed that BP-I and BP-II promoted removal of the virus and conferred protection in mouse lungs. BP-IV significantly reduced viral titers and histopathological changes and contributed to protection against H9N2 AIV challenge in mouse lungs. This study further elucidated the immunoadjuvant activities of BPs I to IV, providing a novel insight into immunoadjuvants for use in vaccine design.
Adjuvants, Immunologic ; Animals ; Antibodies, Neutralizing ; Antibody Formation ; Birds ; Bursa of Fabricius ; Cytokines ; Immunity, Cellular ; Immunity, Humoral ; Influenza A Virus, H9N2 Subtype ; Influenza in Birds ; Lung ; Mice ; Peptides ; T-Lymphocytes, Cytotoxic

The bursa of Fabricius (BF), which is unique to birds, serves as the central humoral immune organ and plays a significant role in B lymphocyte differentiation. In this study, a new bursal peptide (BP-IV) was isolated from BF, which promoted colony-forming unit pre-B formation and regulated B cell differentiation. BP-IV also exerted immunomodulatory effects on antigen-specific immune responses via both humoral and cellular immunity in chicken and mice that had been immunized with inactivated avian influenza virus (AIV; H9N2 subtype), including enhancing AIV-specific antibody and cytokine production. The results of this study provided novel insights into the use of a potential candidate reagent for B cell development and future immuno-pharmacological use.
Animals ; Birds ; Bursa of Fabricius* ; Cell Differentiation ; Chickens* ; Immunity, Cellular ; Influenza in Birds ; Lymphocytes ; Mice ; Stem Cells

The effects of diclazuril on the bursa of Fabricius (BF) structure and secretory IgA (SIgA) expression in chickens infected with Eimeria tenella were examined. The morphology of the BF was observed by hematoxylin and eosin staining, while ultrastructural changes were monitored by transmission electron microscopy. E. tenella infection caused the BF cell volumes to decrease, irregularly arranged, as well as, enlargement of the intercellular space. Diclazuril treatment alleviated the physical signs of damages associated with E. tenella infection. The SIgA expression in BF was analyzed by immunohistochemistry technique. The SIgA expression increased significantly by 350.4% (P<0.01) after E. tenella infection compared to the normal control group. With the treatment of diclazuril, the SIgA was relatively fewer in the cortex, and the expression level was significantly decreased by 46.7% (P<0.01) compared with the infected and untreated group. In conclusion, E. tenella infection in chickens induced obvious harmful changes in BF morphological structure and stimulated the expression of SIgA in the BF. Diclazuril treatment effectively alleviated the morphological changes. This result demonstrates a method to develop an immunological strategy in coccidiosis control.
Animals ; Bursa of Fabricius/anatomy & histology/*parasitology ; Chickens ; Coccidiosis/drug therapy/metabolism/parasitology/*veterinary ; Coccidiostats/administration & dosage/*adverse effects ; Eimeria tenella/*physiology ; Female ; Immunoglobulin A, Secretory/*genetics/metabolism ; Male ; Nitriles/administration & dosage/*adverse effects ; Poultry Diseases/*drug therapy/genetics/metabolism/parasitology ; Triazines/administration & dosage/*adverse effects

The bursa of Fabricius (BF) is the acknowledged central humoral immune organ in birds. Bursal septpeptide II (BSP-II) is an immunomodulatory bioactive peptide isolated from BF. To understand the effects of BSP-II on immune induction, gene expression profiles of hybridoma cells treated with BSP-II were evaluated. Pathway analysis showed that regulated genes were involved in cytokine-cytokine receptor interactions, T cell receptor signaling pathway, and pathway in cancer. It was observed that BSP-II reduced tumor cells proliferation and stimulated p53 expression. These results indicate potential mechanisms underlying the effects of the humoral immune system on immune induction, including antitumor activities. Our study has provided a novel insight into immunotherapeutic strategies for treating human tumors.
Animals ; Antineoplastic Agents/*pharmacology ; Avian Proteins/*pharmacology ; Bursa of Fabricius/immunology ; Cell Proliferation/drug effects ; Chickens/*immunology ; Hybridomas/drug effects ; Immunologic Factors/*pharmacology ; Oligonucleotide Array Sequence Analysis/veterinary ; Signal Transduction/*drug effects ; *Transcriptome

The aim of this work was to investigate developmental changes in cell proliferation and apoptosis in normal duck bursa of Fabricius using flow cytometry and immunohistochemistry. Studies were carried out on Tianfu ducks on days 24 and 27 of embryogenesis (E24 and E27) along with days 20, 70, and 200 of postnatal development (P20, P70, and P200). Results showed that the percentage of G0/G1 bursa cells significantly increased between E24 and P200 while the percentage of cells in the S phase or G2 + M phase as well as the proliferating index obviously decreased during the same period. Proliferation cell nuclear antigen was detected in lymphocyte and interfollicular epithelium. The proliferative lymphocyte density tended to decrease from E24 to P200. Apoptotic bodies in macrophages, free apoptotic bodies, or nuclei with condensed chromatin in lymphocytes in follicles were identified by transferase-mediated dUTP nick-end labeling. Both flow cytometry and microscopic analysis reveal that the proportion of apoptotic cells and apoptotic lymphocyte density increased from E24 to P20, fell on P70, then rose again on P200. Our foundings demonstrate that cell proliferation decreases and apoptosis increases with age. These changes may account for duck bursa development and involution.
Animals ; *Apoptosis ; Bursa of Fabricius/*cytology/embryology/growth & development/*physiology ; Cell Proliferation ; Ducks/embryology/*physiology ; Embryo, Nonmammalian/cytology/embryology ; Embryonic Development ; Epithelium/physiology ; Female ; Flow Cytometry/veterinary ; Immunohistochemistry/veterinary ; Lymphocytes/physiology ; Male

To screen the interactive proteins with IBDV Gt VP2 protein from cDNA library of B Lymphoid cells of the bursa of Fabricius. The expression cDNA library plasmids was transformed to the yeast competent cells, which have the bait plasmid-Gt VP2. After testing for growth in synthetic complete medium lacking histidine and uracil and for production of beta-galactosidase (X-gal), we obtained 16 positive clones. We searched the gene sequences of positive clones in the NCBI website. The blast results showed that five positive clones were the gallus sequences. They were Gallus gallus breed mitochondrial DNA, O_G1cNAc transferase, Tumor protein p53 binding protein, Stathmin and Chondroitin sulfate Ga1NAcT-2, respectively. This study is helpful for the further identifying the receptors of IBDV in B Lymphoid cells of the bursa of Fabricius.
Animals ; B-Lymphocytes ; metabolism ; virology ; Bursa of Fabricius ; metabolism ; Chickens ; DNA, Mitochondrial ; metabolism ; Gene Library ; Infectious bursal disease virus ; Protein Binding ; Protein Interaction Mapping ; Receptors, Virus ; metabolism ; Tumor Suppressor Protein p53 ; metabolism ; Two-Hybrid System Techniques ; Viral Structural Proteins ; genetics ; metabolism

The aim of this study was to examine the efficacy of in ovo prime-boost vaccination against infectious bursal disease virus (IBDV) using a DNA vaccine to prime in ovo followed by a killed-vaccine boost post hatching. In addition, the adjuvant effects of plasmid-encoded chicken interleukin-2 and chicken interferon-gamma were tested in conjunction with the vaccine. A plasmid DNA vaccine (pcDNA-VP243) encoding the VP2, VP4, and VP3 proteins of the very virulent IBDV (vvIBDV) SH/92 strain was injected into the amniotic sac alone or in combination with a plasmid encoding chicken IL-2 (ChIL-2) or chicken IFN-gamma (ChIFN-gamma) at embryonation day 18, followed by an intramuscular injection of a commercial killed IBD vaccine at 1 week of age. The chickens were orally challenged with the vvIBDV SH/92 strain at 3 weeks of age and observed for 10 days. In ovo DNA immunization followed by a killed-vaccine boost provided significantly better immunity than the other options. No mortality was observed in this group after a challenge with the vvIBDV. The prime-boost strategy was moderately effective against bursal damage, which was measured by the bursa weight/body weight ratio, the presence of IBDV RNA, and the bursal lesion score. In ovo DNA vaccination with no boost did not provide sufficient immunity, and the addition of ChIL-2 or ChIFN-gamma did not enhance protective immunity. In the ConA-induced lymphocyte proliferation assay of peripheral blood lymphocyte collected 10 days post-challenge, there was greater proliferation responses in the DNA vaccine plus boost and DNA vaccine with ChIL-2 plus boost groups compared to the other groups. These findings suggest that priming with DNA vaccine and boosting with killed vaccine is an effective strategy for protecting chickens against vvIBDV.
Adjuvants, Immunologic/pharmacology ; Animals ; Antibodies, Viral/blood ; Birnaviridae Infections/immunology/prevention & control/*veterinary/virology ; Body Weight/immunology ; Bursa of Fabricius/immunology ; Chick Embryo ; *Chickens ; Histocytochemistry/veterinary ; Immunization/*veterinary ; Infectious bursal disease virus/genetics/*immunology ; Interferon-gamma/pharmacology ; Interleukin-2/pharmacology ; Organ Size/immunology ; Poultry Diseases/immunology/*prevention & control/virology ; RNA, Viral/chemistry/genetics ; Random Allocation ; Reverse Transcriptase Polymerase Chain Reaction/veterinary ; Specific Pathogen-Free Organisms ; Vaccines, DNA/*administration & dosage/immunology ; Vaccines, Inactivated/administration & dosage/immunology ; Viral Vaccines/*administration & dosage/immunology

Infectious bursal disease virus (IBDV) causes a highly contagious and immunosuppressive disease of chicken. Agar gel immunodiffusion using IBDV antigen extracted from bursa of Fabricius of infected chicken has been used officially for diagnosis of IBDV in Korea. In this study, in order to replace the IBDV whole virus antigen with non-infectious antigen, recombinant VP2 protein (rVP2) of IBDV was produced using recombinant baculovirus expression system. Purified baculovirus-expressed rVP2 was used as an antigen in an agar gel immunodiffusion (AGID). rVP2 antigen precipitated specifically IBDV antibodies. AGID using rVP2 antigen detected anti-IBDV antibodies from 6 dpi to 28 dpi (termination of the experiment) when specific pathogen free chickens were experimentally infected with IBDV 52/70 strain. This was consistent with result by AGID using IBDV antigen, virus neutralization test (VNT) and a commercial ELISA kit (except for one serum). The sensitivity of rVP2 was the same with that of IBDV antigen when field sera (n=324) were tested by AGID. However, AGID using rVP2 antigen detected maternal antibodies from broiler chickens (n=20) on a broiler farm up to 15 days old, although the detection rate of the AGID was relatively low compared to a commercial ELISA kit. Our results indicate that IBDV whole virus antigen from IBDV infected chickens would be replaced with recombinant VP2 protein as an antigen for AGID.
Agar ; Animals ; Antibodies ; Baculoviridae ; Bursa of Fabricius ; Chickens ; Enzyme-Linked Immunosorbent Assay ; Immunodiffusion ; Infectious bursal disease virus ; Korea ; Neutralization Tests ; Specific Pathogen-Free Organisms ; Sprains and Strains ; Staphylococcal Protein A ; Viruses

This study examined the adjuvant effects of dimethyl dioctadecyl ammonium bromide (DDA), CpG oligodeoxynucleotides (CpG-ODN), and chicken interferon-gamma (ChIFN-gamma) on a DNA vaccine (pcDNA-VP243) against the infectious bursal disease virus (IBDV). A plasmid encoding chicken IFN-atilde was constructed. Twice at 2-week intervals, twoweek-old chickens were injected intramuscularly and intraperitoneally with either a DNA vaccine alone or a DNA vaccine together with the respective adjuvants. On week 2 after the second immunization, the chickens were orally challenged with the highly virulent IBDV. The groups that received the DNA vaccines plus either DDA or CpG-ODN showed significantly lower survival rates than the group that received the DNA vaccine alone. However, the survival rates for the DNA vaccine alone and for the DNA vaccine plus ChIFN-gamma were similar. The chickens had no detectable antibodies to the IBDV before the challenge but all the surviving chickens in all groups except for the normal control group showed the induction of antibodies to the IBDV at day 10 after the challenge. As judged by the lymphocyte proliferation assays using the a WST-8 solution performed on the peripheral blood and splenic lymphocytes, the stimulation indices (SI) of the peripheral blood lymphocytes in all groups except for the normal control group were similar immediately before the challenge. At 10 days post-challenge, the SI for DNA vaccine plus either CpG-ODN or ChIFN-gamma was similar to that of the DNA vaccine control group. For splenic lymphocytes, the SI in the DNA vaccine plus CpG-ODN and DNA vaccine plus ChIFN-gamma groups were higher than for the DNA vaccine control. These results suggest that DDA actually compromises the protection against the IBDV by DNA vaccine, and CpG-ODN and IFN-gamma had no significant effect.
Adjuvants, Immunologic ; Animals ; Antibodies, Viral/blood ; Birnaviridae Infections/*immunology/*prevention & control/virology ; Bursa of Fabricius/immunology/virology ; Cell Proliferation ; Chickens ; CpG Islands/immunology ; Enzyme-Linked Immunosorbent Assay/veterinary ; Immunization/methods/*veterinary ; Infectious bursal disease virus/*immunology ; Interferon-gamma/immunology/therapeutic use ; Lymphocytes/cytology/immunology ; Oligonucleotides/immunology ; Poultry Diseases/immunology/*prevention & control/*virology ; Specific Pathogen-Free Organisms ; Vaccines, DNA/immunology/therapeutic use ; Viral Vaccines/*immunology/therapeutic use

This study describes the histochemical characteristics and ultrastructure of mast cells from tongue, proventriculus, ileum and fabricius bursa, in pheasant (Phasianus colchicus) by light and electron microscopy. We compared the stainability of 4 different methods, toluidine blue, alcian blue, congo red and alkaline Giemsa, to stain mast cell granules from fixed pheasant organs in three different fixatives, 10% neutral buffered formalin, Carnoy's solution or half-strength Karnovsky's solution. Mast cells in all experimental organs were not stained with 4 different staining methods after fixation in 10% neutral buffered formalin but well stained in fixed organs with half-strength Karnovsky's solution. The mast cells had many metachromatic granules stained with toluidine blue or alkaline Giemsa and orthochromatic granules stained with alcian blue or congo red in tissues fixed in half-strength Karnovsky's solution. In electron microscopy, pheasant mast cells were oval, triangular, spindle-like or irregular and had a few finger-like cytoplasmic processes. There were the membrane-bounded secretory granules and the well-developed organelles in mast cells. Internal large granules were oval or irregular, and had variable shape; some higher or lower electron density with homogeneous appearance; some had a particular appearance, and a few showed reticular or spongy-like structure. This indicates that 10% neutral buffered formalin or Carnoy's fixation may be inadequate for detection of mast cells in pheasant, whereas the half-strength Karnovsky's fixation provides metachromatic or orthochromatic staining of mast cell granules.
Alcian Blue ; Animals ; Bursa of Fabricius ; Congo Red ; Cytoplasm ; Fixatives ; Formaldehyde ; Ileum ; Mast Cells* ; Microscopy, Electron ; Organelles ; Proventriculus ; Secretory Vesicles ; Tolonium Chloride ; Tongue