Duodenal mucosa of untreated celiac disease patients has altered expression of the GAS6 and PROS1 and the negative regulator tyrosine kinase TAM receptors subfamily.

Celiac disease (CD) is an immune-driven disease characterized by tissue damage in the small intestine of genetically-susceptible individuals. We evaluated here a crucial immune regulatory pathway involving TYRO3, AXL, and MERTK (TAM) receptors and their ligands PROS1 and GAS6 in duodenal biopsies of controls and CD patients. We found increased GAS6 expression associated with downregulation of PROS1 and variable TAM receptors levels in duodenum tissue of CD patients. Interestingly, CD3+ lymphocytes, CD68+, CD11c+ myeloid and epithelial cells, showed differential expressions of TAM components comparing CD vs controls. Principal component analysis revealed a clear segregation of two groups of CD patients based on TAM components and IFN signaling. In vitro validation demonstrated that monocytes, T lymphocytes and epithelial cells upregulated TAM components in response to IFN stimulation. Our findings highlight a dysregulated TAM axis in CD related to IFN signaling and contribute to a deeper understanding of the pathophysiology of CD.

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition).

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.

In vitro presentation of gliadin-derived peptides by different cell lines.

BACKGROUND: Gliadin peptide presentation and T-cell activation are critical events in the pathogenesis of celiac disease. Several studies have been performed to identify the toxic gliadin peptides but the complexity of the antigenic fraction makes this analysis difficult. In this work, an in vitro model for the analysis of gliadin peptide presentation is studied. METHODS: The human cell lines U937 and THP-1 (monocytic), DUCAF and VAVY (immortalised B cells) and HT-29 and Caco-2 (intestinal epithelial cells) were incubated with biotin-labelled gliadin (bG). FITC-labelled streptavidin was used to detect biotinylated peptides at the cell surface by flow cytometry. RESULTS: All cell lines tested showed a fluorescence signal derived from bG, that was highest when cells were stimulated with IFN-gamma for 48 h. Time course experiments performed using THP-1 cells showed that after 4-h incubation, almost a maximal signal can be reached. THP-1 cells incubated at 4 degrees C or after paraformaldehyde fixation showed a substantial signal reduction, suggesting that metabolic activity was necessary for the detection of the maximal fluorescence signal at the cell surface. The presence of HLA class II-bound biotinylated peptides was observed in cell lysates of THP-1 cells incubated with bG. CONCLUSIONS: In all cell lines tested, a specific biotin-peptide-derived signal was observed. This was increased after IFN-gamma treatment and decreased after fixation or incubation at low temperature. The signal was higher in monocytic and B-cell lines than in the epithelial cell lines. The use of this procedure could be a useful tool to study the in vitro processing and presentation of naturally gliadin-derived peptides.

Desarrollo de un ELISA de alta detectabilidad y especificidad para la cuantificación de gliadinas en alimentos destinados a enfermos celíacos / Development of a quantitative ELISA to determination of gladins in food aimed to coeliac patients

La enfermedad celíaca (EC) es una enfermedad gastrointestinal crónica de muy alta incidencia en nuestro país. Se estima que puede afectar 1 de cada 300 habitantes. En individuos susceptibles, la patología es provocada por la ingestión de mínimas cantidades de prolaminas de los cereales: trigo, triticale, cebada y centeno. Su único tratamiento es una estricta dieta libre de dichas proteínas. La Organización Mundial de la Salud (OMS) establece que un alimento puede ser considerado como apto para consumo por enfermos celíacos sólo si su contenido de gluten es inferior a 1 mg/100 g de producto seco. La detección precisa de estas proteínas requiere entonces de métodos de alta detectabilidad y especificidad para discriminar entre las proteínas nocivas y las de otros vegetales frecuentemente usados como reemplazo en la formulación de los alimentos para estos pacientes. En este trabajo, se muestra el desarrollo de un ELISA con anticuerpos policlonales, para la cuantificación de gliadinas en alimentos destinados a enfermos celíacos. Se empleó un diseño de ELISA competitivo secuencial con un antisuero obtenido en conejos que detecta selectivamente las prolaminas tóxicas. Este inmunoensayo presenta un nivel de detección de 0,1 mg de gluten/100 g de producto y cumple con los niveles de detectabilidad aconsejados por la OMS. Mediante el ELISA descripto se han analizado una gran variedad de muestras comerciales, pudiendo cuantificar las prolaminas incluso en alimentos que sufrieron tratamientos térmicos durante su fabricación