Discovery and Differential Processing of HLA Class II-Restricted Minor Histocompatibility Antigen LB-PIP4K2A-1S and Its Allelic Variant by Asparagine Endopeptidase

Minor histocompatibility antigens are the main targets of donor-derived T-cells after allogeneic stem cell transplantation. Identification of these antigens and understanding their biology are a key requisite for more insight into how graft vs. leukemia effect and graft vs. host disease could be separated. We here identified four new HLA class II-restricted minor histocompatibility antigens using whole genome association scanning. For one of the new antigens, i.e., LB-PIP4K2A-1S, we measured strong T-cell recognition of the donor variant PIP4K2A-1N when pulsed as exogenous peptide, while the endogenously expressed variant in donor EBV-B cells was not recognized. We showed that lack of T-cell recognition was caused by intracellular cleavage by a protease named asparagine endopeptidase (AEP). Furthermore, microarray gene expression analysis showed that PIP4K2A and AEP are both ubiquitously expressed in a wide variety of healthy tissues, but that expression levels of AEP were lower in primary acute myeloid leukemia (AML). In line with that, we confirmed low activity of AEP in AML cells and demonstrated that HLA-DRB1*03:01 positive primary AML expressing LB-PIP4K2A-1S or its donor variant PIP4K2A-1N were both recognized by specific T-cells. In conclusion, LB-PIP4K2A-1S not only represents a novel minor histocompatibility antigen but also provides evidence that donor T-cells after allogeneic stem cell transplantation can target the autologous allelic variant as leukemia-associated antigen. Furthermore, it demonstrates that endopeptidases can play a role in cell type-specific intracellular processing and presentation of HLA class II-restricted antigens, which may be explored in future immunotherapy of AML

Cancer Stemness in Apc- vs. Apc/KRAS-Driven Intestinal Tumorigenesis

Constitutive activation of the Wnt pathway leads to adenoma formation, an obligatory step towards intestinal cancer. In view of the established role of Wnt in regulating stemness, we attempted the isolation of cancer stem cells (CSCs) from Apc- and Apc/KRAS-mutant intestinal tumours. Whereas CSCs are present in Apc/KRAS tumours, they appear to be very rare (®-catenin intracellular stabilization

Seladelpar treatment reduces interleukin-31 and pruritus in patients with primary biliary cholangitis

BACKGROUND AND AIMS: Pruritus is a debilitating symptom for many people living with primary biliary cholangitis (PBC). In studies with seladelpar, a selective PPAR-delta agonist, PBC patients experienced significant improvement in pruritus and reduction of serum bile acids. Interleukin-31 (IL-31) is a cytokine known to mediate pruritus and blocking IL-31 signaling provides relief in pruritic skin diseases. This study examined the connection between seladelpar's anti-pruritic effects, IL-31 and bile acid levels in PBC patients. APPROACH AND RESULTS: IL-31 levels were quantified in serum samples from the ENHANCE study of PBC patients receiving daily oral doses of placebo (n=55), seladelpar 5 mg (n=53) or 10 mg (n=53) for 3 months and for healthy volunteers (n=55). IL-31 levels were compared with pruritus using a numerical rating scale (NRS, 0-10) and with bile acid levels. Baseline IL-31 levels closely correlated with pruritus NRS (r=0.54, p<0.0001), and total (r=0.54, p<0.0001) and conjugated bile acids (up to 0.64, p<0.0001). Decreases in IL-31 were observed with seladelpar 5 mg (-30%, p=0.0003) and 10 mg (-52%, p<0.0001) versus placebo (+31%). Patients with clinically meaningful improvement in pruritus (NRS≥2 decrease) demonstrated greater dose-dependent reductions in IL-31 compared to those without pruritus improvement (NRS<2 decrease). Strong correlations were observed for the changes between levels of IL-31 and total bile acids (r=0.63, p<0.0001) in the seladelpar 10 mg group. CONCLUSIONS: Seladelpar decreased serum IL-31 and bile acids in PBC patients. The reductions of IL-31 and bile acids correlated closely with each other and pruritus improvement suggesting a mechanism to explain seladelpar's anti-pruritic effects

Gentherapie der Hämophilie: Empfehlung der Gesellschaft für Thrombose- und Hämostaseforschung (GTH).

Gene therapy has recently become a realistic treatment perspective for patients with haemophilia. Reviewing the literature and our personal experience from clinical trials, we discuss key aspects of haemophilia A and B gene therapy with vectors derived from adeno-associated virus (AAV), including predictable results, risks, adverse events, and patient-reported outcomes. Patient selection, informed consent, administration, and monitoring of gene therapy as well as data collection are explained. We also discuss the need for interdisciplinary cooperation with hepatology and other specialties. We emphasize structural and organizational requirements for treatment centres according to the hub-and-spoke model and recommend the use of electronic diaries to ensure safe and timely collection and exchange of data. Electronic diaries will play a key role as primary source of data for pharmacovigilance, post-marketing clinical studies, national and international registries, as well as health technology and benefit assessment. Reimbursement aspects and the future of gene therapy in adolescents and children are also considered. In a rapidly evolving scientific environment, these recommendations aim to support treatment providers and payers to prepare for the implementation of gene therapy following marketing authorization

Tumor-specific mutations in low-frequency genes affect their functional properties

Causal genetic changes in oligodendrogliomas (OD) with 1p/19q co-deletion include mutations in IDH1, IDH2, CIC, FUBP1, TERT promoter and NOTCH1. However, it is generally assumed that more somatic mutations are required for tumorigenesis. This study aimed to establish whether genes mutated at low frequency can be involved in OD initiation and/or progression. We performed whole-genome sequencing on three anaplastic ODs with 1p/19q co-deletion. To estimate mutation frequency, we performed targeted resequencing on an additional 39 ODs. Whole-genome sequencing identified a total of 55 coding mutations (range 8–32 mutations per tumor), including known abnormalities in IDH1, IDH2, CIC and FUBP1. We also identified mutations in genes, most of which were previously not implicated in ODs. Targeted resequencing on 39 additional ODs confirmed that these genes are mutated at low frequency. Most of the mutations identified were predicted to have a deleterious functional effect. Functional analysis on a subset of these genes (e.g. NTN4 and MAGEH1) showed that the mutation affects the subcellular localization of the protein (n = 2/12). In addition, HOG cells stably expressing mutant GDI1 or XPO7 showed altered cell proliferation compared to those expressing wildtype constructs. Similarly, HOG cells expressing mutant SASH3 or GDI1 showed altered migration. The significantly higher rate of predicted deleterious mutations, the changes in subcellular localization and the effects on proliferation and/or migration indicate that many of these genes functionally may contribute to gliomagenesis and/or progression. These low-frequency genes and their affected pathways may provide new treatment targets for this tumor type

Childhood cancer and hematological disorders negatively affect spermatogonial quantity at diagnosis : a retrospective study of a male fertility preservation cohort

Peer reviewe

Microbe sampling by mucosal dendritic cells is a discrete, MyD88-independent stepin ΔinvG S. Typhimurium colitis

Intestinal dendritic cells (DCs) are believed to sample and present commensal bacteria to the gut-associated immune system to maintain immune homeostasis. How antigen sampling pathways handle intestinal pathogens remains elusive. We present a murine colitogenic Salmonella infection model that is highly dependent on DCs. Conditional DC depletion experiments revealed that intestinal virulence of S. Typhimurium SL1344 ΔinvG mutant lacking a functional type 3 secretion system-1 (ΔinvG)critically required DCs for invasion across the epithelium. The DC-dependency was limited to the early phase of infection when bacteria colocalized with CD11c+CX3CR1+ mucosal DCs. At later stages, the bacteria became associated with other (CD11c−CX3CR1−) lamina propria cells, DC depletion no longer attenuated the pathology, and a MyD88-dependent mucosal inflammation was initiated. Using bone marrow chimeric mice, we showed that the MyD88 signaling within hematopoietic cells, which are distinct from DCs, was required and sufficient for induction of the colitis. Moreover, MyD88-deficient DCs supported transepithelial uptake of the bacteria and the induction of MyD88-dependent colitis. These results establish that pathogen sampling by DCs is a discrete, and MyD88-independent, step during the initiation of a mucosal innate immune response to bacterial infection in vivo

Differentiation of In Vitro–Modified Human Peripheral Blood Monocytes Into Hepatocyte–like and Pancreatic Islet-like Cells

BACKGROUND & AIMS: Adult stem cells provide a promising alternative for the treatment of diabetes mellitus and end-stage liver diseases. We evaluated the differentiation potential of human peripheral blood monocytes into hepatocyte-like and pancreatic islet-like cells. METHODS: Monocytes were treated with macrophage colony-stimulating factor and interleukin 3 for 6 days, followed by incubation with hepatocyte and pancreatic islet-specific differentiation media. Cells were characterized by flow cytometry, gene-expression analysis, metabolic assays, and transplantation for their state of differentiation and tissue-specific functions. RESULTS: In response to macrophage colony-stimulating factor and interleukin 3, monocytes resumed cell division in a CD115-dependent fashion, which was associated with a down-regulation of the PRDM1 and ICSBP genes. These programmable cells of monocytic origin were capable of differentiating into neohepatocytes, which closely resemble primary human hepatocytes with respect to morphology, expression of hepatocyte markers, and specific metabolic functions. After transplantation into the liver of severe combined immunodeficiency disease/nonobese diabetic mice, neohepatocytes integrated well into the liver tissue and showed a morphology and albumin expression similar to that of primary human hepatocytes transplanted under identical conditions. Programmable cells of monocytic origin-derived pancreatic neoislets expressed beta cell-specific transcription factors, secreted insulin and C peptide in a glucose-dependent manner, and normalized blood glucose levels when xenotransplanted into immunocompetent, streptozotocin-treated diabetic mice. Programmable cells of monocytic origin retained monocytic characteristics, notably CD14 expression, a monocyte-specific methylation pattern of the CD115 gene, and expression of the transcription factor PU.1. CONCLUSIONS: The ability to reprogram, expand, and differentiate peripheral blood monocytes in large quantities opens the real possibility of the clinical application of programmable cells of monocytic origin in tissue repair and organ regeneration

Pollitt syndrome patients carry mutation in TTDN1

Complete human genome sequencing was used to identify the causative mutation in a family with Pollitt syndrome (MIM #. 275550), comprising two non-consanguineous parents and their two affected children. The patient's symptoms were reminiscent of the non-photosensitive form of recessively inherited trichothiodystrophy (TTD). A mutation in the TTDN1/. C7orf11 gene, a gene that is known to be involved in non-photosensitive TTD, had been excluded by others by Sanger sequencing. Unexpectedly, we did find a homozygous single-base pair deletion in the coding region of this gene, a mutation that is known to cause non-photosensitive TTD. The deleterious variant causing a frame shift at amino acid 93 (C326delA) followed the right mode of inheritance in the family and was independently validated using conventional DNA sequencing. We expect this novel DNA sequencing technology to help redefine phenotypic and genomic variation in patients with (mono) genetic disorders in an unprecedented manner

Bio-adrenomedullin as a marker of congestion in patients with new-onset and worsening heart failure

Background Secretion of adrenomedullin (ADM) is stimulated by volume overload to maintain endothelial barrier function, and higher levels of biologically active (bio-) ADM in heart failure (HF) are a counteracting response to vascular leakage and tissue oedema. This study aimed to establish the value of plasma bio-ADM as a marker of congestion in patients with worsening HF. Methods and results The association of plasma bio-ADM with clinical markers of congestion, as well as its prognostic value was studied in 2179 patients with new-onset or worsening HF enrolled in BIOSTAT-CHF. Data were validated in a separate cohort of 1703 patients. Patients with higher plasma bio-ADM levels were older, had more severe HF and more signs and symptoms of congestion (all P <0.001). Amongst 20 biomarkers, bio-ADM was the strongest predictor of a clinical congestion score (r(2) = 0.198). In multivariable regression analysis, higher bio-ADM was associated with higher body mass index, more oedema, and higher fibroblast growth factor 23. In hierarchical cluster analysis, bio-ADM clustered with oedema, orthopnoea, rales, hepatomegaly and jugular venous pressure. Higher bio-ADM was independently associated with impaired up-titration of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers after 3 months, but not of beta-blockers. Higher bio-ADM levels were independently associated with an increased risk of all-cause mortality and HF hospitalization (hazard ratio 1.16, 95% confidence interval 1.06-1.27, P = 0.002, per log increase). Analyses in the validation cohort yielded comparable findings. Conclusions Plasma bio-ADM in patients with new-onset and worsening HF is associated with more severe HF and more oedema, orthopnoea, hepatomegaly and jugular venous pressure. We therefore postulate bio-ADM as a congestion marker, which might become useful to guide decongestive therapy