title: Immunomodulatory activities of a new pentapeptide (Bursopentin) from the chicken bursa of Fabricius.
abstract: The bursa of Fabricius (BF) is a central immune organ in birds, and some peptides from chicken BF have demonstrated important immune functions. Here, a new 626.27 Da pentapeptide, Bursopentin (BP5, Cys-Lys-Arg-Val-Tyr) was isolated and purified by reverse-phase high-performance liquid chromatography. In this study, we examined the effects of BP5 on antigen-specific immune response in BALB/c mice sensitized with inactivated avian influenza virus (AIV) [A/Duck/Jiangsu/NJ08/05 (AIV H9N2 subtype)]. The results suggested that BP5 enhanced anti-hemagglutinin antibody (IgG, the isotypes IgG1 and IgG2a) production, induced both of Th1- (IL-2 and IFN-γ) and Th2-type (IL-4 and -10) cytokines, increased proliferations of splenic lymphocyte subsets CD4+ T cells (CD3+CD4+), CD8+ T cells (CD3+CD8+) and B cells, and enhanced cytotoxic T-lymphocyte activity of the activated splenocytes against NIH3T3 cells. The effects of BP5 on the proliferation of isolated T- and/or B-cell populations of BALB/c mice were assessed, and the data suggested that BP5 promoted spleen lymphocyte proliferation by activating B cells directly and T cells indirectly. Further analysis revealed that B-lymphocyte proliferation induced by BP5 is mediated by reactive oxygen species generated from thiol auto-oxidation of BP5. Furthermore, our data indicated that protein kinase C, mitogen-activated protein kinase, and nuclear factor kappa B are involved in the signal transductions during the BP5-induced B lymphocyte proliferation. This study indicates that BP5 could be a potential immunomodulator for future immuno-pharmacological use.
authors.affiliation: Key Laboratory of Animal Disease Diagnosis and Immunology of Ministry of Agriculture of the People's Republic of China, Nanjing Agricultural University, Nanjing, 210095, People's Republic of China.
authors.forename: D Y
authors.initials: DY
authors.lastname: Li
authors.forename: Z R
authors.initials: ZR
authors.lastname: Geng
authors.forename: H F
authors.initials: HF
authors.lastname: Zhu
authors.forename: C
authors.initials: C
authors.lastname: Wang
authors.forename: D N
authors.initials: DN
authors.lastname: Miao
authors.forename: P Y
authors.initials: PY
authors.lastname: Chen
mesh_terms: D000818:Animals; D002060:Bursa of Fabricius / Q000737:chemistry* / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology; D002645:Chickens / Q000276:immunology*; D016207:Cytokines / Q000276:immunology; D005260:Female; D007155:Immunologic Factors / Q000276:immunology* / Q000302:isolation & purification / Q000627:therapeutic use; D009980:Influenza A virus / Q000276:immunology / Q000502:physiology; D005585:Influenza in Birds / Q000188:drug therapy / Q000276:immunology / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D041681:NIH 3T3 Cells; D009842:Oligopeptides / Q000276:immunology* / Q000302:isolation & purification / Q000627:therapeutic use; D011201:Poultry Diseases / Q000188:drug therapy / Q000276:immunology / Q000821:virology
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D009842:Oligopeptides