Tissue alarmins and adaptive cytokine induce dynamic and distinct transcriptional responses in tissue-resident intraepithelial cytotoxic T lymphocytes.

The respective effects of tissue alarmins interleukin (IL)-15 and interferon beta (IFNß), and IL-21 produced by T cells on the reprogramming of cytotoxic T lymphocytes (CTLs) that cause tissue destruction in celiac disease is poorly understood. Transcriptomic and epigenetic profiling of primary intestinal CTLs showed massive and distinct temporal transcriptional changes in response to tissue alarmins, while the impact of IL-21 was limited. Only anti-viral pathways were induced in response to all the three stimuli, albeit with differences in dynamics and strength. Moreover, changes in gene expression were primarily independent of changes in H3K27ac, suggesting that other regulatory mechanisms drive the robust transcriptional response. Finally, we found that IL-15/IFNß/IL-21 transcriptional signatures could be linked to transcriptional alterations in risk loci for complex immune diseases. Together these results provide new insights into molecular mechanisms that fuel the activation of CTLs under conditions that emulate the inflammatory environment in patients with autoimmune diseases.

Immunochip meta-analysis in European and Argentinian populations identifies two novel genetic loci associated with celiac disease.

Celiac disease (CeD) is a common immune-mediated disease of the small intestine that is triggered by exposure to dietary gluten. While the HLA locus plays a major role in disease susceptibility, 39 non-HLA loci were also identified in a study of 24,269 individuals. We now build on this earlier study by adding 4125 additional Caucasian samples including an Argentinian cohort. In doing so, we not only confirm the previous associations, we also identify two novel independent genome-wide significant associations at loci: 12p13.31 and 22q13.1. By applying a genomics approach and differential expression analysis in CeD intestinal biopsies, we prioritize potential causal genes at these novel loci, including LTBR, CYTH4, and RAC2. Nineteen prioritized causal genes are overlapping known drug targets. Pathway enrichment analysis and expression of these genes in CeD biopsies suggest that they have roles in regulating multiple pathways such as the tumor necrosis factor (TNF) mediated signaling pathway and positive regulation of I-κB kinase/NF-κB signaling.

Functional implications of disease-specific variants in loci jointly associated with coeliac disease and rheumatoid arthritis.

Hundreds of genomic loci have been associated with a significant number of immune-mediated diseases, and a large proportion of these associated loci are shared among traits. Both the molecular mechanisms by which these loci confer disease susceptibility and the extent to which shared loci are implicated in a common pathogenesis are unknown. We therefore sought to dissect the functional components at loci shared between two autoimmune diseases: coeliac disease (CeD) and rheumatoid arthritis (RA). We used a cohort of 12 381 CeD cases and 7827 controls, and another cohort of 13 819 RA cases and 12 897 controls, all genotyped with the Immunochip platform. In the joint analysis, we replicated 19 previously identified loci shared by CeD and RA and discovered five new non-HLA loci shared by CeD and RA. Our fine-mapping results indicate that in nine of 24 shared loci the associated variants are distinct in the two diseases. Using cell-type-specific histone markers, we observed that loci which pointed to the same variants in both diseases were enriched for marks of promoters active in CD14+ and CD34+ immune cells (P < 0.001), while loci pointing to distinct variants in one of the two diseases showed enrichment for marks of more specialized cell types, like CD4+ regulatory T cells in CeD (P < 0.0001) compared with Th17 and CD15+ in RA (P = 0.0029).

In vitro susceptibility of Trypanosoma cruzi strains from Santander, Colombia, to hexadecylphosphocholine (miltefosine), nifurtimox and benznidazole

Introduction. The current chemotherapy for Chagas disease is unsatisfactory with only two drugs available for treatment. Research to discover new drugs for Chagas disease is urgent. Hexadecyl-phosphocholine (HPC, miltefosine) has been demonstrated to have in vitro activity against Trypanosoma cruzi parasites, but its activity on different Colombian T. cruzi strains is not known. Objective. To evaluate the in vitro susceptibility of T. cruzi strains isolated from humans and vectors in Santander, Colombia, to miltefosine, nifurtimox and benznidazole. Materials and methods. Eight T. cruzi Colombian strains and three reference strains (Esmeraldo, SilvioX10 and Y) were studied. Drug activities against extracellular epimastigotes and intracellular amastigotes were determined by microscopic counting. The results were expressed as the concentrations that inhibited 50% and 90% growth (IC50 and IC90). Results. For miltefosine a similar range of drug activity was observed against all the Colombian strains, all parasites being more susceptible to miltefosine than to the reference drugs. The intracellular amastigotes were more susceptible to miltefosine (IC50 0.08 to 0.63 ìM and IC90 0.21 to 2.21 ìM) than extracellular forms (IC50 <0.92 to 2.29 ìM and IC90 1.38 to 4.76 ìM). For reference drugs, parasites were more susceptible to nifurtimox than to benznidazole and some differences in activity of benznidazole between T. cruzi strains was observed. Conclusions. The results showed the significant in vitro activity of miltefosine against T. cruzi stages, and the expected results for the reference drugs. Further in vivo studies with miltefosine are planned.

Introducción. Los tratamientos actuales para la enfermedad de Chagas son insatisfactorios y sólo existen dos medicamentos disponibles. La búsqueda de alternativas terapéuticas es prioritaria. La hexadecilfosfocolina (miltefosina) ha mostrado actividad in vitro contra Trypanosoma cruzi. Sin embargo, su actividad en aislamientos de T. cruzi obtenidos en Colombia aún no ha sido reportada. Objetivo. Evaluar la susceptibilidad in vitro a miltefosina, nifurtimox y benznidazole de cepas de T. cruzi aisladas de humanos y vectores en Santander, Colombia. Materiales y métodos. Se evaluó la susceptibilidad de los tres medicamentos en ocho cepas colombianas de T. cruzi y tres cepas de referencia: Esmeraldo, Silvio X10 y Y. La actividad de los compuestos fue determinada en epimastigotes extracelulares y amastigotes intracelulares, por conteo microscópico. Los resultados se expresaron en concentraciones inhibitorias 50 y 90 (CI50 y CI90). Resultados. Para la miltefosina, se observaron rangos similares en la actividad del medicamento entre las cepas colombianas; todos los parásitos fueron más susceptibles a la miltefosina que a los medicamentos de referencia. Los amastigotes intracelulares fueron más sensibles a la miltefosina (CI50, 0,08 a 0,63 µM y CI90, 0,21 a 2,21 µM) que las formas extracelulares (CI50, <0,92 a 2,29 µM y CI90, 1,38 a 4,76 µM). En los medicamentos de referencia, los parásitos fueron más susceptibles al nifurtimox que al benznidazole. Se observaron algunas diferencias en la actividad del benznidazole en las cepas estudiadas de T. cruzi. Conclusiones. Los resultados obtenidos de la actividad in vitro de miltefosina y de los medicamentos de referencia contra aislamientos de T. cruzi son satisfactorios y serán considerados en estudios posteriores in vivo.

In vitro susceptibility of Trypanosoma cruzi strains from Santander, Colombia, to hexadecylphosphocholine (miltefosine), nifurtimox and benznidazole.

INTRODUCTION: The current chemotherapy for Chagas disease is unsatisfactory with only two drugs available for treatment. Research to discover new drugs for Chagas disease is urgent. Hexadecyl-phosphocholine (HPC, miltefosine) has been demonstrated to have in vitro activity against Trypanosoma cruzi parasites, but its activity on different Colombian T. cruzi strains is not known. OBJECTIVE: To evaluate the in vitro susceptibility of T. cruzi strains isolated from humans and vectors in Santander, Colombia. to miltefosine, nifurtimox and benznidazole. MATERIALS AND METHODS: Eight T. cruzi Colombian strains and three reference strains (Esmeraldo, SilvioX10 and Y) were studied. Drug activities against extracellular epimastigotes and intracellular amastigotes were determined by microscopic counting. The results were expressed as the concentrations that inhibited 50% and 90% growth (IC50 and IC90). RESULTS: For miltefosine a similar range of drug activity was observed against all the Colombian strains, all parasites being more susceptible to miltefosine than to the reference drugs. The intracellular amastigotes were more susceptible to miltefosine (IC50 0.08 to 0.63 microM and IC90 0.21 to 2.21 microM) than extracellular forms (IC50 <0.92 to 2.29 microM and IC90 1.38 to 4.76 microM). For reference drugs, parasites were more susceptible to nifurtimox than to benznidazole and some differences in activity of benznidazole between T. cruzi strains was observed. CONCLUSIONS: The results showed the significant in vitro activity of miltefosine against T. cruzi stages, and the expected results for the reference drugs. Further in vivo studies with miltefosine are planned.