title: Chicken intestine defensins activated murine peripheral blood mononuclear cells through the TLR4-NF-kappaB pathway.
abstract: Defensins serve as alarm signals in mobilizing the immune system and activating the innate and adaptive immune responses. In order to investigate whether avian defensins could activate monocytes of another species, and whether chicken defensins could modulate or amplify the adaptive immune responses of murine through the TLR-NF-kappaB pathway, the relationship between the chicken intestinal defensin AvBD13 and TLR4 in murine peripheral blood mononuclear cells (PBMCs) was explored in vitro. Monocytes were stimulated with AvBD13 (1 microg/mL). The levels of NF-kappaB p65, CD80, CD86, IL-12 and IFN-alpha were measured by immunohistochemical analysis of the cells or enzyme-linked immunosorbent assay (ELISA), and the TLR4 levels in monocytes were measured by flow-cytometry. We found that AvBD13 can activate NF-kappaB, induce the inflammatory cytokines IL-12 and IFN-alpha, and upregulate costimulatory molecules like CD80 and monocyte proliferation, which was clearly inhibited by the anti-TLR4 antibody. TLR4 expression was rapidly downregulated in the presence of AvBD13. AvBD13 could modulate monocytes directly and serve as an endogenous ligand for TLR4 and upregulate costimulatory molecules and monocyte proliferation. Thus, TLR4 is involved in AvBD13-mediated activation of adaptive immune responses.
authors.affiliation: College of Animal and Veterinary Science, Henan Agricultural University, Zhengzhou 450002, PR China. yangyu7712@sina.com
authors.forename: YuRong
authors.initials: Y
authors.lastname: Yang
authors.forename: YiBao
authors.initials: Y
authors.lastname: Jiang
authors.forename: QingQiang
authors.initials: Q
authors.lastname: Yin
authors.forename: HongDe
authors.initials: H
authors.lastname: Liang
authors.forename: RuiPing
authors.initials: R
authors.lastname: She
mesh_terms: D000818:Animals; D018122:B7-1 Antigen / Q000032:analysis / Q000276:immunology; D051940:B7-2 Antigen / Q000276:immunology; D049109:Cell Proliferation; D002645:Chickens / Q000097:blood / Q000276:immunology*; D005434:Flow Cytometry; D016898:Interferon-alpha / Q000032:analysis / Q000276:immunology; D018664:Interleukin-12 / Q000032:analysis / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000032:analysis / Q000276:immunology*; D009504:Neutrophils / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000032:analysis / Q000276:immunology*; D023083:beta-Defensins / Q000276:immunology*
chemical_list: D018122:B7-1 Antigen; D051940:B7-2 Antigen; D016898:Interferon-alpha; D016328:NF-kappa B; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; D023083:beta-Defensins; D018664:Interleukin-12