Pharmacological Improvement of CFTR Function Rescues Airway Epithelial Homeostasis and Host Defense in Children with Cystic Fibrosis.

RATIONALE: Pharmacological improvement of CFTR function with elexacaftor/tezacaftor/ivacaftor (ETI) provides unprecedented improvements in lung function and other clinical outcomes to patients with cystic fibrosis (CF). However, ETI effects on impaired mucosal homeostasis and host defense at the molecular and cellular level in the airways of CF patients remain unknown. OBJECTIVES: To investigate effects of ETI on the transcriptiome of nasal epithelial and immune cells from children with CF at the single cell level. METHODS: Nasal swabs from 13 children with CF and at least one F508del allele aged 6 to 11 years were collected at baseline and three months after initiation of ETI, subjected to scRNA-seq and compared to swabs from 12 age-matched healthy children. MEASUREMENTS AND MAIN RESULTS: Proportions of CFTR-positive cells were decreased in epithelial basal, club and goblet cells, but not in ionocytes from children with CF at baseline and were restored on ETI therapy to near healthy levels. Single cell transcriptomics revealed an impaired interferon signalling and reduced expression of MHC I and II encoding genes in epithelial cells of CF children at baseline, which was partially restored by ETI. Additionally, ETI therapy markedly reduced the inflammatory phenotype of immune cells, particularly of neutrophils and macrophages. CONCLUSIONS: Pharmacological improvement of CFTR function improves innate mucosal immunity and reduces immune cell inflammatory responses in the upper airways of children with CF at the single cell level, highlighting the potential to restore epithelial homeostasis and host defense in CF airways by early initiation of ETI therapy. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Genome-wide DNA methylation sequencing identifies epigenetic perturbations in the upper airways under long-term exposure to moderate levels of ambient air pollution.

While the link between exposure to high levels of ambient particulate matter (PM) and increased incidences of respiratory and cardiovascular diseases is widely recognized, recent epidemiological studies have shown that low PM concentrations are equally associated with adverse health effects. As DNA methylation is one of the main mechanisms by which cells regulate and stabilize gene expression, changes in the methylome could constitute early indicators of dysregulated signaling pathways. So far, little is known about PM-associated DNA methylation changes in the upper airways, the first point of contact between airborne pollutants and the human body. Here, we focused on cells of the upper respiratory tract and assessed their genome-wide DNA methylation pattern to explore exposure-associated early regulatory changes. Using a mobile epidemiological laboratory, nasal lavage samples were collected from a cohort of 60 adults that lived in districts with records of low (Simmerath) or moderate (Stuttgart) PM10 levels in Germany. PM10 concentrations were verified by particle measurements on the days of the sample collection and genome-wide DNA methylation was determined by enzymatic methyl sequencing at single-base resolution. We identified 231 differentially methylated regions (DMRs) between moderately and lowly PM10 exposed individuals. A high proportion of DMRs overlapped with regulatory elements, and DMR target genes were involved in pathways regulating cellular redox homeostasis and immune response. In addition, we found distinct changes in DNA methylation of the HOXA gene cluster whose methylation levels have previously been linked to air pollution exposure but also to carcinogenesis in several instances. The findings of this study suggest that regulatory changes in upper airway cells occur at PM10 levels below current European thresholds, some of which may be involved in the development of air pollution-related diseases.

Reconstitution of EBV-directed T cell immunity by adoptive transfer of peptide-stimulated T cells in a patient after allogeneic stem cell transplantation for AITL.

Reconstitution of the T cell repertoire after allogeneic stem cell transplantation is a long and often incomplete process. As a result, reactivation of Epstein-Barr virus (EBV) is a frequent complication that may be treated by adoptive transfer of donor-derived EBV-specific T cells. We generated donor-derived EBV-specific T cells by stimulation with peptides representing defined epitopes covering multiple HLA restrictions. T cells were adoptively transferred to a patient who had developed persisting high titers of EBV after allogeneic stem cell transplantation for angioimmunoblastic T-cell lymphoma (AITL). T cell receptor beta (TCRß) deep sequencing showed that the T cell repertoire of the patient early after transplantation (day 60) was strongly reduced and only very low numbers of EBV-specific T cells were detectable. Manufacturing and in vitro expansion of donor-derived EBV-specific T cells resulted in enrichment of EBV epitope-specific, HLA-restricted T cells. Monitoring of T cell clonotypes at a molecular level after adoptive transfer revealed that the dominant TCR sequences from peptide-stimulated T cells persisted long-term and established an EBV-specific TCR clonotype repertoire in the host, with many of the EBV-specific TCRs present in the donor. This reconstituted repertoire was associated with immunological control of EBV and with lack of further AITL relapse.

T-cell repertoires in refractory coeliac disease.

OBJECTIVE: Refractory coeliac disease (RCD) is a potentially hazardous complication of coeliac disease (CD). In contrast to RCD type I, RCD type II is a precursor entity of enteropathy-associated T-cell lymphoma (EATL), which is associated with clonally expanding T-cells that are also found in the sequentially developing EATL. Using high-throughput sequencing (HTS), we aimed to establish the small-intestinal T-cell repertoire (TCR) in CD and RCD to unravel the role of distinct T-cell clonotypes in RCD pathogenesis. DESIGN: DNA extracted from duodenal mucosa specimens of controls (n=9), active coeliacs (n=10), coeliacs on a gluten-free diet (n=9), RCD type I (n=8), RCD type II (n=8) and unclassified Marsh I cases (n=3) collected from 2002 to 2013 was examined by TCRß-complementarity-determining regions 3 (CDR3) multiplex PCR followed by HTS of the amplicons. RESULTS: On average, 106 sequence reads per sample were generated consisting of up to 900 individual TCRß rearrangements. In RCD type II, the most frequent clonotypes (ie, sequence reads with identical CDR3) represent in average 42.6% of all TCRß rearrangements, which was significantly higher than in controls (6.8%; p<0.01) or RCD type I (6.7%; p<0.01). Repeat endoscopies in individual patients revealed stability of clonotypes for up to several years without clinical symptoms of EATL. Dominant clonotypes identified in individual patients with RCD type II were unique and not related between patients. CD-associated, gliadin-dependent CDR3 motifs were only detectable at low frequencies. CONCLUSIONS: TCRß-HTS analysis unravels the TCR in CD and allows detailed analysis of individual TCRß rearrangements. Dominant TCRß sequences identified in patients with RCD type II are unique and not homologous to known gliadin-specific TCR sequences, supporting the assumption that these clonal T-cells expand independent of gluten stimulation.

A novel approach to detect resistance mechanisms reveals FGR as a factor mediating HDAC inhibitor SAHA resistance in B-cell lymphoma.

Histone deacetylase (HDAC) inhibitors such as suberoylanilide hydroxamic acid (SAHA) are not commonly used in clinical practice for treatment of B-cell lymphomas, although a subset of patients with refractory or relapsed B-cell lymphoma achieved partial or complete remissions. Therefore, the purpose of this study was to identify molecular features that predict the response of B-cell lymphomas to SAHA treatment. We designed an integrative approach combining drug efficacy testing with exome and captured target analysis (DETECT). In this study, we tested SAHA sensitivity in 26 B-cell lymphoma cell lines and determined SAHA-interacting proteins in SAHA resistant and sensitive cell lines employing a SAHA capture compound (CC) and mass spectrometry (CCMS). In addition, we performed exome mutation analysis. Candidate validation was done by expression analysis and knock-out experiments. An integrated network analysis revealed that the Src tyrosine kinase Gardner-Rasheed feline sarcoma viral (v-fgr) oncogene homolog (FGR) is associated with SAHA resistance. FGR was specifically captured by the SAHA-CC in resistant cells. In line with this observation, we found that FGR expression was significantly higher in SAHA resistant cell lines. As functional proof, CRISPR/Cas9 mediated FGR knock-out in resistant cells increased SAHA sensitivity. In silico analysis of B-cell lymphoma samples (n = 1200) showed a wide range of FGR expression indicating that FGR expression might help to stratify patients, which clinically benefit from SAHA therapy. In conclusion, our comprehensive analysis of SAHA-interacting proteins highlights FGR as a factor involved in SAHA resistance in B-cell lymphoma.

Performance evaluation of the DNA methylation biomarker SHOX2 for the aid in diagnosis of lung cancer based on the analysis of bronchial aspirates.

In the identification of subjects with lung cancer, increased DNA methylation of the SHOX2 gene locus in bronchial aspirates has previously been proven to be a clinically valuable biomarker. This is particularly true in cases where the cytological and histological results following bronchoscopy are undetermined. This previous case control study was conducted using research assay components and a complex work flow. To facilitate the use in a diagnostic setting, a CE marked in vitro diagnostic test kit to quantify SHOX2 DNA methylation in bronchial aspirates was developed and characterized. The presented assay for measuring SHOX2 DNA methylation in bronchial aspirates is based on two major steps: generation of bisulfite converted template DNA from patient samples followed by subsequent determination of SHOX2 biomarker methylation by real-time PCR. Individual kits for DNA preparation, real-time PCR analysis and work flow control were developed. This study describes the analytical performance (reproducibility, accuracy, interfering substances, cross-reactivity) of the in vitro diagnostic (IVD) test kit 'Epi proLung BL Reflex Assay'. In addition, the intended use of the test was validated in a clinical performance evaluation (case control) study comprised of 250 patients (125 cases, 125 controls). The results describe the test as a robust and reliable diagnostic tool for identifying patients with lung cancer using Saccomanno-fixed bronchial lavage specimens (AUC [95% confidence intervals] = 0.94 [0.91-0.98], sensitivity 78% [69-86]/specificity 96% [90-99]). This test may be used as a diagnostic adjunct to existing clinical and pathological investigations in lung cancer.

SHOX2 DNA methylation is a biomarker for the diagnosis of lung cancer in plasma.

INTRODUCTION: Recently, analysis of DNA methylation of the SHOX2 locus was shown to reliably identify lung cancer in bronchial aspirates of patients with disease. As a plasma-based assay would expand the possible applications of the SHOX2 biomarker, this study aimed to develop a modified SHOX2 assay for use in a blood-based test and to analyze the performance of this optimized SHOX2 methylation assay in plasma. METHODS: Quantitative real-time polymerase chain reaction was used to analyze DNA methylation of SHOX2 in plasma samples from 411 individuals. A training study (20 stage IV patients with lung cancer and 20 controls) was performed to show the feasibility of detecting the SHOX2 biomarker in blood and to determine a methylation cutoff for patient classification. The resulting cutoff was verified in a testing study composed of 371 plasma samples from patients with lung cancer and controls. RESULTS: DNA methylation of SHOX2 could be used as a biomarker to distinguish between malignant lung disease and controls at a sensitivity of 60% (95% confidence interval: 53-67%) and a specificity of 90% (95% confidence interval: 84-94%). Cancer in patients with stages II (72%), III (55%), and IV (83%) was detected at a higher sensitivity when compared with stage I patients. Small cell lung cancer (80%) and squamous cell carcinoma (63%) were detected at the highest sensitivity when compared with adenocarcinomas. CONCLUSIONS: SHOX2 DNA methylation is a biomarker for detecting the presence of malignant lung disease in blood plasma from patients with lung cancer.

Correlation of SHOX2 gene amplification and DNA methylation in lung cancer tumors.

BACKGROUND: DNA methylation in the SHOX2 locus was previously used to reliably detect lung cancer in a group of critical controls, including 'cytologically negative' samples with no visible tumor cell content, at a high specificity based on the analysis of bronchial lavage samples. This study aimed to investigate, if the methylation correlates with SHOX2 gene expression and/or copy number alterations. An amplification of the SHOX2 gene locus together with the observed tumor-specific hypermethylation might explain the good performance of this marker in bronchial lavage samples. METHODS: SHOX2 expression, gene copy number and DNA methylation were determined in lung tumor tissues and matched morphologically normal adjacent tissues (NAT) from 55 lung cancer patients. Quantitative HeavyMethyl (HM) real-time PCR was used to detect SHOX2 DNA methylation levels. SHOX2 expression was assayed with quantitative real-time PCR, and copy numbers alterations were measured with conventional real-time PCR and array CGH. RESULTS: A hypermethylation of the SHOX2 locus in tumor tissue as compared to the matched NAT from the same patient was detected in 96% of tumors from a group of 55 lung cancer patients. This correlated highly significantly with the frequent occurrence of copy number amplification (p < 0.0001), while the expression of the SHOX2 gene showed no difference. CONCLUSIONS: Frequent gene amplification correlated with hypermethylation of the SHOX2 gene locus. This concerted effect qualifies SHOX2 DNA methylation as a biomarker for lung cancer diagnosis, especially when sensitive detection is needed, i.e. in bronchial lavage or blood samples.

SHOX2 DNA methylation is a biomarker for the diagnosis of lung cancer based on bronchial aspirates.

BACKGROUND: This study aimed to show that SHOX2 DNA methylation is a tumor marker in patients with suspected lung cancer by using bronchial fluid aspirated during bronchoscopy. Such a biomarker would be clinically valuable, especially when, following the first bronchoscopy, a final diagnosis cannot be established by histology or cytology. A test with a low false positive rate can reduce the need for further invasive and costly procedures and ensure early treatment. METHODS: Marker discovery was carried out by differential methylation hybridization (DMH) and real-time PCR. The real-time PCR based HeavyMethyl technology was used for quantitative analysis of DNA methylation of SHOX2 using bronchial aspirates from two clinical centres in a case-control study. Fresh-frozen and Saccomanno-fixed samples were used to show the tumor marker performance in different sample types of clinical relevance. RESULTS: Valid measurements were obtained from a total of 523 patient samples (242 controls, 281 cases). DNA methylation of SHOX2 allowed to distinguish between malignant and benign lung disease, i.e. abscesses, infections, obstructive lung diseases, sarcoidosis, scleroderma, stenoses, at high specificity (68% sensitivity [95% CI 62-73%], 95% specificity [95% CI 91-97%]). CONCLUSIONS: Hypermethylation of SHOX2 in bronchial aspirates appears to be a clinically useful tumor marker for identifying subjects with lung carcinoma, especially if histological and cytological findings after bronchoscopy are ambiguous.

A novel method for sensitive and specific detection of DNA methylation biomarkers based on DNA restriction during PCR cycling.

DNA methylation is an important epigenetic mechanism involved in fundamental biological processes such as development, imprinting, and carcino-genesis. For these reasons, DNA methylation represents a valuable source for cancer biomarkers. Methods for the sensitive and specific detection of methylated DNA are a prerequisite for the implementation of DNA biomarkers into clinical routine when early detection based on the analysis of body fluids is desired. Here, a novel technique is presented for the detection of DNA methylation biomarkers, based on real-time PCR of bisulfite-treated template with enzymatic digestion of background DNA during amplification using the heat-stable enzyme Tsp509I. An assay for the lung cancer methylation biomarker BARHL2 was used to show clinical and analytical performance of the method in comparison with methylation-specific PCR technology. Both technologies showed comparable performance when analyzing technical DNA mixtures and bronchial lavage samples from 75 patients suspected of having lung cancer. The results demonstrate that the approach is useful for sensitive and specific detection of a few copies of methylated DNA in samples with a high background of unmethylated DNA, such as in clinical samples from body fluids.