RESUMEN
Crohn's disease (CD) is an inflammatory pathology of the mucosal intestine that results from uncontrolled immune response towards commensal microbes. Clonal expansions of T cells have been found in patients with CD suggesting an antigen-specific stimulation of pathogenic T cells. Here we show, using T-cell receptor repertoire analysis by real-time PCR, that oligoclonal expansions are found in both CD8+ and CD4+ T cells in the blood and intestinal mucosa of CD patients. The majority of CD4+ T-cell-expanded clones are CD4+NKG2D+ T cells. These clonal expansions were found in both inflamed and neighboring healthy tissue and were persisting during the course of the disease. The presence of these CD4+NKG2D+ T-cell clones at the macroscopically normal edge of the surgical resection might be predictive of inflammation relapse post surgery.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Enfermedad de Crohn/inmunología , Enfermedad de Crohn/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Subfamilia K de Receptores Similares a Lectina de Células NK/metabolismo , Adulto , Linfocitos T CD8-positivos/inmunología , Estudios de Casos y Controles , Enfermedad de Crohn/cirugía , Femenino , Humanos , Íleon/inmunología , Íleon/metabolismo , Íleon/patología , Masculino , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T alfa-beta/metabolismo , Recurrencia , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Adulto JovenRESUMEN
Multimeric enzymes that lose their quaternary structure often cease to be catalytically competent. In these cases, conformational stability depends on contacts between subunits, and minor mutations affecting the surface of the monomers may affect overall stability. This effect may be sensitive to pH, temperature, or solvent composition. We investigated the role of oligomeric structure in protein stability by heat and chemical denaturation of hexameric nucleoside diphosphate kinase from Dictyostelium discoideum and its P105G mutant over a wide range of pH. The wild-type enzyme has been reported to unfold without prior dissociation into monomers, whereas monomer unfolding follows dissociation for the P105G mutant (Giartosio et al. (1996) J. Biol. Chem. 271, 17845-51). We show here that these features are also preserved at alkaline pH, with the wild-type enzyme always hexameric at room temperature whereas the mutant dissociates into monomers at pH >or=10. In acidic conditions (pH Asunto(s)
Dictyostelium/enzimología
, Nucleósido-Difosfato Quinasa/química
, Sustitución de Aminoácidos/genética
, Naftalenosulfonatos de Anilina/química
, Animales
, Rastreo Diferencial de Calorimetría
, Cromatografía en Gel
, Dicroismo Circular
, Activación Enzimática
, Estabilidad de Enzimas
, Colorantes Fluorescentes/química
, Concentración de Iones de Hidrógeno
, Nucleósido-Difosfato Quinasa/metabolismo
, Unión Proteica
, Desnaturalización Proteica
, Pliegue de Proteína
, Renaturación de Proteína
, Estructura Cuaternaria de Proteína
, Proteínas Recombinantes/química
, Proteínas Recombinantes/metabolismo
, Espectrometría de Fluorescencia
, Termodinámica
, Urea/química