Expression of CD226 is associated to but not required for NK cell education

AbstractDNAX accessory molecule-1 (DNAM-1, also known as CD226) is an activating receptor expressed on subsets of natural killer (NK) and T cells, interacts with its ligands CD155 or CD112, and has co-varied expression with inhibitory receptors. Since inhibitory receptors control NK-cell activation and are necessary for MHC-I-dependent education, we investigated whether DNAM-1 expression is also involved in NK-cell education. Here we show an MHC-I-dependent correlation between DNAM-1 expression and NK-cell education, and an association between DNAM-1 and NKG2A that occurs even in MHC class I deficient mice. DNAM-1 is expressed early during NK-cell development, precedes the expression of MHC-I-specific inhibitory receptors, and is modulated in an education-dependent fashion. Cd226−/− mice have missing self-responses and NK cells with a normal receptor repertoire. We propose a model in which NK-cell education prevents or delays downregulation of DNAM-1. This molecule endows educated NK cells with enhanced effector functions but is dispensable for education.</jats:p

Dasatinib crosses the blood-brain barrier and is an efficient therapy for central nervous system philadelphia chromosome positive leukemia

Although imatinib, a BCR-ABL tyrosine kinase inhibitor, is used to treat acute Philadelphia chromosome-positive (Ph+) leukemia, it does not prevent central nervous system (CNS) relapses resulting from poor drug penetration through the blood-brain barrier. Imatinib and dasatinib (a dual-specific SRC/BCR-ABL kinase inhibitor) were compared in a pre-clinical mouse model of intracranial Ph+ leukemia. Clinical dasatinib treatment in patients with CNS Ph+ leukemia was assessed. In preclinical studies, dasatinib increased survival, whereas imatinib failed to inhibit intracranial tumor growth. Stabilization and regression of CNS disease were achieved with continued dasatinib administration. The drug also demonstrated substantial activity in 11 adult and pediatric patients with CNS Ph+ leukemia. Eleven evaluable patients had clinically significant, long-lasting responses, which were complete in 7 patients. In 3 additional patients, isolated CNS relapse occurred during dasatinib therapy; and in 2 of them, it was caused by expansion of a BCR-ABL-mutated dasatinib-resistant clone, implying selection pressure exerted by the compound in the CNS. Dasatinib has promising therapeutic potential in managing intracranial leukemic disease and substantial clinical activity in patients who experience CNS relapse while on imatinib therapy. This study is registered at ClinicalTrials. gov as CA180006 (#NCT00108719) and CA180015 (#NCT00110097)

Identification of Genomic Regions Associated with Phenotypic Variation between Dog Breeds using Selection Mapping

Peer reviewe

Changes in energy metabolism due to acute rotenone-induced mitochondrial complex I dysfunction – An in vivo large animal model

Metabolic crisis is a clinical condition primarily affecting patients with inherent mitochondrial dysfunction in situations of augmented energy demand. To model this, ten pigs received an infusion of rotenone, a mitochondrial complex I inhibitor, or vehicle. Clinical parameters, blood gases, continuous indirect calorimetry, in vivo muscle oxygen tension, ex vivo mitochondrial respiration and metabolomics were assessed. Rotenone induced a progressive increase in blood lactate which was paralleled by an increase in oxygen tension in venous blood and skeletal muscle. There was an initial decrease in whole body oxygen utilization, and there was a trend towards inhibited mitochondrial respiration in platelets. While levels of succinate were decreased, other intermediates of glycolysis and the TCA cycle were increased. This model may be suited for evaluating pharmaceutical interventions aimed at counteracting metabolic changes due to complex I dysfunction

Cancer Risk in Collagenous Colitis

Data on malignancy in patients with collagenous colitis (CC) is scarce. We aimed to determine the incidence of cancers in patients with CC. In a two-stages, observational study, data on cancers in patients diagnosed with CC during 2000-2015, were collected from two cohorts. The risk was calculated according to the age-standardized rate for the first cohort and according to the standardized incidence ratio for the second cohort. The first cohort comprised 738 patients (394 from Scotland and 344 from Sweden; mean age 71 ± 11 and 66 ± 13 years, respectively). The incidence rates for lung cancer (RR 3.9, p = 0.001), bladder cancer (RR 9.2, p = 0.019), and non-melanoma skin cancer (NMSC) (RR 15, p = 0.001) were increased. As the majority of NMSC cases (15/16) came from Sweden, a second Swedish cohort, comprising 1141 patients (863 women, mean age 65 years, range 20-95 years) was collected. There were 93 cancer cases (besides NMSC). The risk for colon cancer was decreased (SIR 0.23, p= 0.0087). The risk for cutaneous squamous cell carcinoma was instead markedly increased (SIR 3.27, p = 0.001)

Multiple apical plasma membrane constituents are associated with susceptibility to meconium ileus in individuals with cystic fibrosis

Variants associated with meconium ileus in cystic fibrosis (CF) were identified in 3,763 patients by GWAS. Five SNPs at two loci near SLC6A14 (min P=1.28×10(−12) at rs3788766), chr Xq23-24 and SLC26A9 (min P=9.88×10(−9) at rs4077468), chr 1q32.1 accounted for ~5% of the phenotypic variability, and were replicated in an independent patient collection (n=2,372; P=0.001 and 0.0001 respectively). By incorporating that disease-causing mutations in CFTR alter electrolyte and fluid flux across epithelia into an hypothesis-driven genome-wide analysis (GWAS-HD), we identified the same SLC6A14 and SLC26A9 associated SNPs, while establishing evidence for the involvement of SNPs in a third solute carrier gene, SLC9A3. In addition, GWAS-HD provided evidence of association between meconium ileus and multiple constituents of the apical plasma membrane where CFTR resides (P=0.0002, testing 155 apical genes jointly and replicated, P=0.022). These findings suggest that modulating activities of apical membrane constituents could complement current therapeutic paradigms for cystic fibrosis