RESUMEN
An acidic O-specific polysaccharide from the lipopolysaccharide of Proteus mirabilis O10 contains 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, D-galacturonic acid, and L-altruronic acid, the last-named sugar having not been found hitherto in O-antigens. Structure of a branched tetrasaccharide repeating unit of the polysaccharide was established by 1H and 13C NMR spectroscopy, including two-dimensional COSY and rotating-frame NOE spectroscopy. The lateral L-altruronic acid residue plays the immunodominant role in manifestation of the O10 specificity of Proteus, whereas a disaccharide fragment of the main chain in common with the O-specific polysaccharide of P. mirabilis O43 provides the one-way serological cross-reactivity between anti-O10 serum and O43-antigen.
Asunto(s)
Antígenos O/química , Antígenos O/inmunología , Proteus mirabilis/inmunología , Ácidos Urónicos/análisis , Anticuerpos Antibacterianos/sangre , Secuencia de Carbohidratos , Reacciones Cruzadas , Ensayo de Inmunoadsorción Enzimática , Epítopos , Glicosilación , Hemólisis , Humanos , Espectroscopía de Resonancia Magnética , Datos de Secuencia Molecular , Oxidación-Reducción , Pruebas de Precipitina , Ácidos Urónicos/inmunologíaRESUMEN
L-ficolin (also called ficolin-2, P35 or hucolin) is a soluble pattern recognition molecule of suspected importance in anti-microbial immunity. It activates the lectin pathway of complement and acts as an opsonin. l-ficolin, encoded by the FCN2 gene, recognizes microbial polysaccharides and glycoconjugates rich in GlcNAc or GalNAc. We report here data concerning four single nucleotide polymorphisms (SNPs) of the FCN2 gene and their relationship to l-ficolin serum concentrations. There are two pairs of SNPs in linkage disequilibrium: ss32469536 (located in promoter) with rs7851696 (in exon 8) and ss32469537 (promoter) with ss32469544 (exon 8). We selected groups possessing low or high serum l-ficolin concentrations (
Asunto(s)
Lectinas/sangre , Lectinas/genética , Polimorfismo de Nucleótido Simple , Infecciones del Sistema Respiratorio/genética , Adolescente , Niño , Preescolar , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Inmunidad Innata/genética , Lactante , Recurrencia , Infecciones del Sistema Respiratorio/inmunología , FicolinasRESUMEN
The involvement of mannan-binding lectin (MBL) insufficiency in the pathogenesis of chronic gastritis (CG) in children was investigated. Blood samples were collected from 78 paediatric patients suffering from CG associated with Helicobacter pylori infection (group Hp(+)) and from 41 with the disease not associated with such an infection (group Hp(-)). Control group consisted of 77 children. The frequency of mbl-2 gene mutations and serum protein concentrations did not differ significantly in both groups as compared with controls. An expression of mbl-2 gene in gastric biopsies of CG patients was demonstrated. It was found to be stronger in H. pylori-infected children. The results presented in this paper suggest that MBL deficit/dysfunction probably does not contribute to an increased risk of CG (both associated and not associated with H. pylori infection) in children. However, MBL opsonic effect and/or the lectin pathway of complement activation may be taken into account as possible host defence mechanisms in gastric patients.
Asunto(s)
Gastritis/genética , Lectina de Unión a Manosa/genética , Adolescente , Alelos , Biopsia , Niño , Enfermedad Crónica , ADN/química , ADN/genética , Gastritis/sangre , Gastritis/inmunología , Gastritis/microbiología , Expresión Génica , Genotipo , Infecciones por Helicobacter/sangre , Infecciones por Helicobacter/genética , Infecciones por Helicobacter/inmunología , Helicobacter pylori , Humanos , Lectina de Unión a Manosa/biosíntesis , Lectina de Unión a Manosa/sangre , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Regiones Promotoras Genéticas , Análisis de Secuencia de ADN , Estadísticas no ParamétricasRESUMEN
The lectin pathway of complement activation is used by a collectin, mannan-binding lectin (MBL), and two ficolins, L-ficolin and H-ficolin, to opsonize microorganisms for phagocytosis. We published evidence recently that MBL insufficiency is associated with recurrent respiratory infections in childhood. We have now measured serum L-ficolin in 313 respiratory infection patients and 74 healthy control children. L-ficolin concentrations below the lower limit of the control group were found in 6% of the patients (P <0.02) and were associated most strongly with children having co-existing atopic disorders (11%; P=0.002). We suggest that L-ficolin may have a role in protection from microorganisms complicating allergic disease.