Characterization of host responses induced by Toll-like receptor ligands in chicken cecal tonsil cells.
The innate responses of cecal tonsils against invading microorganisms are mediated by conserved pattern recognition receptors (PRRs) such as the Toll-like receptors (TLRs). TLRs expressed by mammalian and avian immune system cells have the capability to recognize pathogen-associated molecular patterns (PAMPs). Although, the role of TLR ligands in innate and adaptive responses in chickens has been characterized in spleen and bursa of Fabricius, considerably less is known about responses in cecal tonsils. The aim of the current study was to assess responses of mononuclear cells from cecal tonsils to treatment with the TLR2, TLR4 and TLR21 ligands, Pam3CSK4, lipopolysaccharide (LPS), and CpG oligodeoxynucleotide (ODN), respectively. All three ligands induced significant up-regulation of interferon (IFN)-γ, interleukin (IL)-1β, IL-6 and CxCLi2/IL-8, whereas no significant changes were observed in expression of IL-13 or the antimicrobial peptides, avian β-defensin (AvBD) 1, AvBD2 and cathelicidin 3 (CATHL-3). In general, CpG ODN elicited the highest cytokine responses by cecal tonsil mononuclear cells, inducing significantly higher expression compared to LPS and Pam3CSK4, for IFNγ, IL-1β, IL-6 and CxCLi2 at various time points. These findings suggest the potential use of TLR21 ligands as mucosal vaccine adjuvants, especially in the context of pathogens of the intestinal tract.
['Taha-Abdelaziz|Khaled|K|', 'Alkie|Tamiru Negash|TN|', 'Hodgins|Douglas C|DC|', 'Shojadoost|Bahram|B|', 'Sharif|Shayan|S|']
D000818:Animals D023181:Antimicrobial Cationic Peptides D030161:Avian Proteins D002432:Cecum D002645:Chickens D016207:Cytokines D015870:Gene Expression D006790:Host-Parasite Interactions D018928:Immunity, Mucosal D066298:In Vitro Techniques D008024:Ligands D008221:Lymphoid Tissue D009838:Oligodeoxyribonucleotides D018417:Th1 Cells D018418:Th2 Cells D051193:Toll-Like Receptors
Toll-like receptor Ligands Chicken Cecal tonsils Innate responses Cytokines