NOX1 loss-of-function genetic variants in patients with inflammatory bowel disease.

Genetic defects that affect intestinal epithelial barrier function can present with very early-onset inflammatory bowel disease (VEOIBD). Using whole-genome sequencing, a novel hemizygous defect in NOX1 encoding NAPDH oxidase 1 was identified in a patient with ulcerative colitis-like VEOIBD. Exome screening of 1,878 pediatric patients identified further seven male inflammatory bowel disease (IBD) patients with rare NOX1 mutations. Loss-of-function was validated in p.N122H and p.T497A, and to a lesser degree in p.Y470H, p.R287Q, p.I67M, p.Q293R as well as the previously described p.P330S, and the common NOX1 SNP p.D360N (rs34688635) variant. The missense mutation p.N122H abrogated reactive oxygen species (ROS) production in cell lines, ex vivo colonic explants, and patient-derived colonic organoid cultures. Within colonic crypts, NOX1 constitutively generates a high level of ROS in the crypt lumen. Analysis of 9,513 controls and 11,140 IBD patients of non-Jewish European ancestry did not reveal an association between p.D360N and IBD. Our data suggest that loss-of-function variants in NOX1 do not cause a Mendelian disorder of high penetrance but are a context-specific modifier. Our results implicate that variants in NOX1 change brush border ROS within colonic crypts at the interface between the epithelium and luminal microbes

Somatic mosaicism and common genetic variation contribute to the risk of very-early-onset inflammatory bowel disease

Abstract: Very-early-onset inflammatory bowel disease (VEO-IBD) is a heterogeneous phenotype associated with a spectrum of rare Mendelian disorders. Here, we perform whole-exome-sequencing and genome-wide genotyping in 145 patients (median age-at-diagnosis of 3.5 years), in whom no Mendelian disorders were clinically suspected. In five patients we detect a primary immunodeficiency or enteropathy, with clinical consequences (XIAP, CYBA, SH2D1A, PCSK1). We also present a case study of a VEO-IBD patient with a mosaic de novo, pathogenic allele in CYBB. The mutation is present in ~70% of phagocytes and sufficient to result in defective bacterial handling but not life-threatening infections. Finally, we show that VEO-IBD patients have, on average, higher IBD polygenic risk scores than population controls (99 patients and 18,780 controls; P < 4 × 10−10), and replicate this finding in an independent cohort of VEO-IBD cases and controls (117 patients and 2,603 controls; P < 5 × 10−10). This discovery indicates that a polygenic component operates in VEO-IBD pathogenesis

Radioactive isotopes in the studies on physiology and biology of parasites

The paper gives examples of employment of nuclear techniques in research on nucleic acids, protein and energy metabolism, turnover and antigenicity of surface proteins and also on development of parasitic protozoans and helmtnths

Przydatnosc metody PCR i jej modyfikacji do diagnozowania inwazji pasozytniczych u przezuwaczy

Sensitivity and specificity are the two most important criteria that define the quality of a diagnostic technique. DNA probes and PCR-based techniques may simplify the diagnosis of parasitic infections. PCR is a powerful diagnostics tool. The method enables detection of even a very small amount of DNA. An extreme sensitivity of the PCR, being a major advantage of the method is also a cause of potentially false positive results. To achieve reliable diagnostic results several modifications have been introduced to the classic PCR procedure. PCR and PCR-based techniques are currently increasingly used for detection of parasitic infections, to differentiate closely related species which are difficult to be recognised with traditional methods, for estimation of parasite burdens, and for the detection of drug resistant strains

Nowe rodzaje szczepionek przeciwpasozytniczych

The protection of humans and domestic animals against parasitic infections remains a major goal, especially in light of developing of drug resistant strains in many parasite species. "Classic" vaccines are based on attenuated infective stages of protozoan and helminth parasites. Although such vaccines are effective in confering host immunity against several Protozoan (coccidiosis, giardiosis, toxoplasmosis) diseases and one helminth (dictyocaulosis) they are very unstable and expensive. Recombinant techniques enable to obtain protective antigens quickly and in considerable quantities, cultivating of the bacteria and purification of the recombinant protein is less expensive than the maintenance of host animals and isolation of the protective antigens from harvested parasites. Moreover, the cloned protective antigens may be deprived of epitopes responsible for immunopathology. However, at present only one anti-parasite recombinant protein vaccine is commercially available (TickGARD). Such a situation may result from that many protective parasitic antigens cannot be expressed in bacteria or yeast in anative from. DNA vaccines present many advantages over protein ones. Firstly, the antigenic proteins synthesised within the host cell possess an appropriate molecular structure and undergo a posttranslational modifications specific for a native protein. The next advantage of DNA vaccines is that DNA is easier to handle and more resistant than proteins to temperature changes. DNA vaccines are likely to induce novel mechanisms of i mm une response, which may be beneficial in case of parasitic invasions. Costs of DNA vaccines are comparable, and may be even lower, in comparison to recombinant protein vaccines. The main obstacle preventing the use of DNA vaccines is still Jack of the complete knowledge conceming mechanisms of their action. Vaccines based on transgenic plants (=edible vaccines), expressing the protective parasitic antigens, present another promising approach in research on anti-parasitic vaccines. Such vaccines may be of special importance in prevention of infections with gastrointestinal parasites

Szczepionki DNA w prewencji chorob pasozytniczych: stan obecny i perspektywy

The introduction of genetic or "naked DNA" vaccines may open a new era in vaccinology. DNA vaccination is a relatively simple process: a recombinant vector containing cDNA of the potentially protective pathogen antigen, is delivered to a host organism under the control of a strong promoter. It has been demonstrated that the introduced DNA remains stable as an episome for a long time and does not integrate into a genome of vaccinated organism. The type of immune response elicited by DNA vaccination depends very much on the antigen used and on the way of the vaccine delivery. Generally, DNA vaccination induces Tol-dependent rather than Th2-dependent immune response. DNA vaccines present many advantages over "traditional" ones. Firstly, it is easier to obtain a considerable amount of DNA than similar quantities of purified protective antigen protein. Secondly, the antigenic proteins synthesised within the host cell possess an appropriate molecular structure and undergo a posttranslational modifications specific for the native protein. The posttranslational modifications, for example glycosylation, cannot be introduced during expression of the recombinant protein antigens in bacterial hosts