Positive selection acting on Toll-like receptors (TLRs) has been recently investigated to reveal evolutionary mechanisms of host-pathogen molecular co-adaptation. Much of this research, however, has focused mainly on the identification of sites predicted to be under positive selection, bringing little insight into the functional differences and similarities among species and a limited understanding of convergent evolution in the innate immune molecules. In this study, we provide evidence of phenotypic variability in the avian TLR4 ligand-binding region (LBR), the direct interface between host and pathogen molecular structures. We show that 55 passerine species vary substantially in the distribution of electrostatic potential on the surface of the receptor, and based on these distinct patterns, we identified four species clusters. Seven of the 34 evolutionarily nonconservative and positively selected residues correspond topologically to sites previously identified as being important for lipopolysaccharide, lipid IVa or MD-2 binding. Five of these positions codetermine the identity of the charge clusters. Groups of species that host-related communities of pathogens were predicted to cluster based on their TLR4 LBR charge. Despite some evidence for convergence among taxa, there were no clear associations between the TLR4 LBR charge distribution and any of the general ecological characteristics compared (migration, latitudinal distribution and diet). Closely related species, however, mostly belonged to the same surface charge cluster indicating that phylogenetic constraints are key determinants shaping TLR4 adaptive evolution. Our results suggest that host innate immune evolution is consistent with Fahrenholz's rule on the cospeciation of hosts and their parasites.

• MeSH
• glykolipidy chemie   genetika   MeSH
• interakce hostitele a patogenu genetika   MeSH
• konformace proteinů MeSH
• ligandy MeSH
• lipid A analogy a deriváty   chemie   genetika   MeSH
• lipopolysacharidy chemie   genetika   MeSH
• lymfocytární antigen 96 chemie   genetika   MeSH
• mikrobiota genetika   MeSH
• molekulární evoluce * MeSH
• molekulární modely MeSH
• přirozená imunita genetika   MeSH
• ptáci genetika   parazitologie   MeSH
• sekvenční analýza DNA MeSH
• selekce (genetika) * genetika   MeSH
• statická elektřina MeSH
• toll-like receptor 4 chemie   genetika   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The protective effect of Enterococcus faecium EFAL41 on chicken's caecum in relation to the TLR (TLR4 and TLR21) activation and production of luminal IgA challenged with Campylobacter jejuni CCM6191 was assessed. The activation of MIF, IFN-β, MD-2 and CD14 was followed-up after bacterial infection. Day-old chicks (40) were divided into four groups (n = 10): control (C), E. faecium AL41 (EFAL41), C. jejuni (CJ) and combined E. faecium AL41+C. jejuni (EFAL41+CJ). Relative mRNA expression of TLR4, TLR21 and CD14 was upregulated in the probiotic strain and infected (combined) group on day 4 and 7 post infection (p.i.). The caecal relative MD-2 mRNA expression was upregulated on day 4 p.i. in the EFAL41+CJ and CJ groups. MIF and IFN-β reached the highest levels in the combined groups on day 7 p.i. The concentration of the sIgA in intestinal flush was upregulated in EFAL41+CJ group on day 4 p.i. The results demonstrated that E. faecium EFAL41 probiotic strain can modulate the TLRs expression and modify the activation of MIF, IFN-β, MD-2 and CD14 molecules in the chickens caecum challenged with C. jejuni CCM 6191. The counts of EFAL41 were sufficient and high, similarly the counts of enterococci in both, caecum and faeces but without reduction of Campylobacter counts.

• MeSH
• antigeny CD14 genetika   imunologie   MeSH
• Campylobacter jejuni růst a vývoj   MeSH
• cékum imunologie   mikrobiologie   MeSH
• Enterococcus faecium růst a vývoj   imunologie   MeSH
• feces mikrobiologie   MeSH
• imunoglobulin A sekreční genetika   MeSH
• interakce hostitele a patogenu MeSH
• interferon beta genetika   imunologie   MeSH
• kampylobakterové infekce dietoterapie   imunologie   mikrobiologie   veterinární   MeSH
• kur domácí MeSH
• lymfocytární antigen 96 genetika   imunologie   MeSH
• nemoci drůbeže dietoterapie   genetika   imunologie   mikrobiologie   MeSH
• novorozená zvířata MeSH
• probiotika farmakologie   MeSH
• protein - isoformy genetika   imunologie   MeSH
• receptory imunologické genetika   imunologie   MeSH
• regulace genové exprese MeSH
• signální transdukce MeSH
• toll-like receptor 4 genetika   imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: Expression of the gene encoding Der-p2 allergen-like protein in the castor bean tick Ixodes ricinus is induced by blood intake. Tick Der-p2 allergen-like protein belongs to a diverse family of ML proteins that includes major allergens of house dust mites, human MD-2 or similar proteins from Drosophila melanogaster. In ticks, genes encoding proteins belonging to the ML protein family were identified, but their protein products have not been characterized yet. METHODS: A gene encoding tick Der-p2 allergen-like protein was amplified from cDNA of engorged I. ricinus female using the gene-specific primers designed on a basis of partial sequences of related allergen-like genes. The tissue and state specific patterns of expression of the gene were analysed. The IgE binding activity of the produced recombinant protein was studied by use of ELISA. RESULTS: Analysis of the expression pattern showed that the gene encoding the tick Der-p2 allergen-like protein is strongly induced by the bloodmeal in gut and haemolymph throughout all tick developmental stages. Der-p2 allergen-like protein possesses a putative lipid-binding site, according to the comparisons with the related proteins. The ability of tick Der-p2 allergen-like protein to bind immunoglobulin E (IgE) was revealed. DISCUSSION: The presence of a putative lipid-binding domain in Der-p2 allergen-like protein and its ability to interact with IgE might indicate the involvement of the protein in the tick's immune response.

• MeSH
• alergeny chemie   genetika   imunologie   metabolismus   MeSH
• antigeny roztočů domácího prachu chemie   genetika   imunologie   metabolismus   MeSH
• Dermatophagoides pteronyssinus imunologie   MeSH
• imunoglobulin E imunologie   metabolismus   MeSH
• klíště genetika   růst a vývoj   imunologie   metabolismus   MeSH
• larva růst a vývoj   imunologie   MeSH
• lymfocytární antigen 96 chemie   imunologie   MeSH
• molekulární modely MeSH
• nymfa růst a vývoj   imunologie   MeSH
• rekombinantní proteiny chemie   genetika   imunologie   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sekvenční analýza DNA MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH