Rheumatoid arthritis is a systemic autoinmmune disease mediated by T cells. Productive engagement of T cell receptors by major histocompatibility complex-peptide leads to proliferation, differentiation and the definition of effector functions. Altered peptide ligands (APL) generated by amino acid substitutions in the antigenic peptide have diverse effects on T cell response. We predicted a novel T cell epitope from human heat-shock protein 60, an autoantigen involved in the pathogenesis of rheumatoid arthritis. Three APLs were designed from this epitope and it was demostrated that these peptides induce the activation of T cells through their ability to modify cell cycle phase's distribution of CD4+T cells from RA patients. Also, IL-17, TNF-α and IL-10 levels were determined in PBMC from these patients. Unlike the wild-type peptide and the other two APLs, APL2 increased the IL-10 level and suppressed IL-17 secretion in these assays. Therapeutic effect of this APL in adjuvant arthritis (AA) and collagen-induced arthritis (CIA) models was also evaluated. Clinical score, histopathology, inflammatory and regulatory cytokine concentration were monitored in the animals. APL2 efficiently inhibited the progression of AA and CIA with a significant reduction of the clinical and histopathogic score. Therapeutic effect of APL2 on CIA was similar to that obtained with MTX; the standard treatment for RA. This effect was associated with a decrease of TNF-α and IL-17 levels. These results suggest that the therapeutic effect of APL2 is mediated in part by down-regulation of inflammatory cytokines and support the potential use of APL2 as a therapeutic drug in RA patients.

The present invention is related with the field of the medicine, particularly with the use of an APL peptide or its analogues derived from the human heat shock protein of 60 kDa, for the manufacture of a pharmaceutical composition for the treatment of Crohn's disease, ulcerative colitis and diabetes mellitus type 1. This peptide is biodistributed into the gastrointestinal tract and also promotes the induction of apoptosis in activated intestinal lamina propria and peripheral blood T cells of patients with Crohn's disease. Furthermore, this peptide induces apoptosis in mononuclear cells of patients with diabetes mellitus type 1.

Tryptic digestion of biotinylated Lys-C peptides followed by affinity chromatography allows the selective isolation of lysine-free tryptic peptides delimited by arginine residues (RRnK peptides). In silico analysis revealed that RRnK peptides represent 87% of the whole proteomes and their specific isolation simplifies the complex peptide mixture (5 peptides per protein). The good recoveries and high selectivity obtained in the isolation of RRnK peptides anticipate the applicability of this method in 2DE-free quantitative proteome analyses.

La Artritis Reumatoide es una enfermedad de etiologia multifactorial, que involucra la presencia de factores geneticos, ambientales, inmunologicos y hormonales. En los ultimos anos se ha establecido una asociacion entre la predisposicion a padecer esta enfermedad y la existencia de determinados haplotipos del HLA clase II. El objetivo fundamental de este trabajo es la caracterizacion del polimorfismo de las moleculas HLA-DQB1 y HLA-DRB de un grupo de pacientes cubanos con Artritis Reumatoide, ademas analizar una posible correlacion entre los niveles de varias citocinas proinflamatorias en un grupo de estos pacientes, con los alelos HLA tipo II genotipados, el sexo y el tiempo de diagnosticada la enfermedad. El estudio se llevo a cabo en 50 pacientes cubanos con el diagnostico de Artritis Reumatoide y un grupo control, compuesto de 211 donantes sanos. Los haplotipos HLA-DQ y HLA-DRB1 fueron determinados a traves de la reaccion en cadena de la polimerasa. La cuantificacion de las citocinas se realizo empleando inmuno-ensayos comerciales. Los resultados obtenidos en este analisis indican que los alelos con un radio de la razon de probabilidades superior a 2 fueron para el caso de la molecula HLA-DQB1: HLADQB1*03 y *06, y para la molecula HLA-DRB1 los alelos: *01, *04, *09 y *10. Encontramos ademas que los niveles de la citocina interferon gamma estan significativamente aumentados en los pacientes con menos tiempo de diagnosticada la enfermedad. Este trabajo constituye el primer reporte de caracterizacion de las moleculas HLA tipo II, a traves de tecnicas moleculares, en pacientes cubanos con Artritis Reumatoide.

A method for the selective capture and analysis of peptides containing neither histidine nor arginine is evaluated. It is based on the reversible modification of alpha- and epsilon-amino groups of peptides and the relatively easy separation of charged and noncharged peptides by cation exchange chromatography. The simplicity of the method and the results obtained in silico and with standard proteins, anticipate the utility of the SCAPE approach for proteome analyses.