A toxicology study of Csf2ra complementation and pulmonary macrophage transplantation therapy of hereditary PAP in mice

Pulmonary macrophage transplantation (PMT) is a gene and cell transplantation approach in development as therapy for hereditary pulmonary alveolar proteinosis (hPAP), a surfactant accumulation disorder caused by mutations in CSF2RA/B (and murine homologs). We conducted a toxicology study of PMT of Csf2ra gene-corrected macrophages (mGM-Rα+Mϕs) or saline-control intervention in Csf2raKO or wild-type (WT) mice including single ascending dose and repeat ascending dose studies evaluating safety, tolerability, pharmacokinetics, and pharmacodynamics. Lentiviral-mediated Csf2ra cDNA transfer restored GM-CSF signaling in mGM-Rα+Mϕs. Following PMT, mGM-Rα+Mϕs engrafted, remained within the lungs, and did not undergo uncontrolled proliferation or result in bronchospasm, pulmonary function abnormalities, pulmonary or systemic inflammation, anti-transgene product antibodies, or pulmonary fibrosis. Aggressive male fighting caused a similarly low rate of serious adverse events in saline- and PMT-treated mice. Transient, minor pulmonary neutrophilia and exacerbation of pre-existing hPAP-related lymphocytosis were observed 14 days after PMT of the safety margin dose but not the target dose (5,000,000 or 500,000 mGM-Rα+Mϕs, respectively) and only in Csf2raKO mice but not in WT mice. PMT reduced lung disease severity in Csf2raKO mice. Results indicate PMT of mGM-Rα+Mϕs was safe, well tolerated, and therapeutically efficacious in Csf2raKO mice, and established a no adverse effect level and 10-fold safety margin.

Altered expression of GLS2 indicates a poor prognosis and correlates with clinicopathological features of oral squamous cell carcinoma

Glutamine metabolism, governed by enzymes including glutaminase (GLS1 and GLS2), has a pivotal role in cancer progression. The objective of this study was to determine whether GLS2 transcription levels are associated with oral squamous cell carcinoma (OSCC) when compared to matched adjacent normal tissues. Primary tumour and adjacent normal tissues were collected from 51 OSCC patients, and GLS2 mRNA expression analysis was conducted using real-time qPCR. Additionally, The Cancer Genome Atlas-Head and Neck Squamous Cell Carcinoma (TCGA-HNSCC) dataset was utilized to examine GLS2 expression in relation to clinicopathological features, the prognosis, and tumour immune cell infiltration. A significantly reduced expression of GLS2 mRNA was found in the OSCC tissues when compared to the matched adjacent normal tissue samples (P < 0.001), which aligned with the results from the TCGA-HNSCC dataset and immunohistochemistry. Moreover, GLS2 mRNA expression was associated with clinicopathological features including tumour stage, grade, and human papillomavirus status (all P < 0.05), predicted a poorer prognosis (P = 0.024), and was correlated with tumour immune cell infiltration (all P < 0.05) in head and neck squamous cell carcinoma. Functional pathway analysis indicated its involvement in cell proliferation and metabolic cycles. GLS2 dysregulation is linked to oral cancer, suggesting its potential as a predictive prognostic marker for OSCC. Furthermore, targeting glutaminases via GLS2 may represent a promising therapeutic strategy for OSCC treatment.

A dried blood spot test for diagnosis of autoimmune pulmonary alveolar proteinosis

Granulocyte/macrophage colony-stimulating factor autoantibodies (GMAbs) mediate the pathogenesis of autoimmune pulmonary alveolar proteinosis (autoimmune PAP) and their quantification in serum by enzyme-linked immunosorbent assay (ELISA) - the serum GMAb test - is the 'gold standard' for diagnosis of autoimmune PAP. Because GMAbs are high in autoimmune PAP and low or undetectable in healthy people, we hypothesized that the ELISA could be adapted for evaluation of blood obtained from the fingertip using a dried blood spot card (DBSC) for specimen collection. Here, we report development of such a method - the DBSC GMAb test - and evaluate its ability to measure GMAb concentration in blood and to diagnose autoimmune PAP. Fresh, heparinized whole blood was obtained from 60 autoimmune PAP patients and 19 healthy people and used to measure the GMAb concentration in blood (by the DBSC GMAb test). After optimization, the DBSC GMAb test was evaluated for accuracy, precision, reliability, sensitivity, specificity, and ruggedness. The coefficient of variation among repeated measurements was low with regard to well-to-well, plate-to-plate, day-to-day, and inter-operator variation, and results were unaffected by exposure of prepared DBSC specimens to a wide range of temperatures (from -80 °C to 65 °C), repeated freeze-thaw cycles, or storage for up to 2.5 months before testing. The limit of blank (LoB), limit of detection (LoD), and lower limit of quantification (LLoQ), were 0.01, 0.21, and 3.5 μg/ml of GMAb in the blood, respectively. Receiver operating curve characteristic analysis identified 2.7 μg/ml as the optimal GMAb concentration cutoff value to distinguish autoimmune PAP from healthy people. This cutoff value was less than the LLoQ and the ranges of GMAb results for autoimmune PAP patients and healthy people were widely separated (median (interquartile range): 22.6 (13.3-43.8) and 0.23 (0.20-0.30) μg/ml, respectively). Consequently, the LLoQ is recommended as the lower limit of the range indicating a positive test result (i.e., that autoimmune PAP is present); lower values indicate a negative test result (i.e., autoimmune PAP is not present). Among the 30 autoimmune PAP patients and 19 healthy people evaluated, the sensitivity and specificity of the DBSC GMAb test were both 100% for a diagnosis of autoimmune PAP. Results demonstrate the DBSC GMAb test reliably measures GMAbs in blood and performs well in the diagnosis of autoimmune PAP.

Genome sequencing reveals underdiagnosis of primary ciliary dyskinesia in bronchiectasis

BACKGROUND

Bronchiectasis can result from infectious, genetic, immunological and allergic causes. 60-80% of cases are idiopathic, but a well-recognised genetic cause is the motile ciliopathy, primary ciliary dyskinesia (PCD). Diagnosis of PCD has management implications including addressing comorbidities, implementing genetic and fertility counselling and future access to PCD-specific treatments. Diagnostic testing can be complex; however, PCD genetic testing is moving rapidly from research into clinical diagnostics and would confirm the cause of bronchiectasis.

METHODS

This observational study used genetic data from severe bronchiectasis patients recruited to the UK 100,000 Genomes Project and patients referred for gene panel testing within a tertiary respiratory hospital. Patients referred for genetic testing due to clinical suspicion of PCD were excluded from both analyses. Data were accessed from the British Thoracic Society audit, to investigate whether motile ciliopathies are underdiagnosed in people with bronchiectasis in the UK.

RESULTS

Pathogenic or likely pathogenic variants were identified in motile ciliopathy genes in 17 (12%) out of 142 individuals by whole-genome sequencing. Similarly, in a single centre with access to pathological diagnostic facilities, 5-10% of patients received a PCD diagnosis by gene panel, often linked to normal/inconclusive nasal nitric oxide and cilia functional test results. In 4898 audited patients with bronchiectasis, <2% were tested for PCD and <1% received genetic testing.

CONCLUSIONS

PCD is underdiagnosed as a cause of bronchiectasis. Increased uptake of genetic testing may help to identify bronchiectasis due to motile ciliopathies and ensure appropriate management.

Very long-term outcomes of patients undergoing catheter ablation of atrial fibrillation: a systematic review and meta-analysis

Background

The efficacy of catheter ablation of atrial fibrillation (AF) is reported to stabilise at 5-year, but most studies report up to 3-year-outcomes only.

Objective

To perform a systematic review and meta-analysis of outcomes at 5-years following AF ablation.

Methods

We searched PubMed and Embase for studies reporting on ≥5-year outcomes following AF ablation, including freedom from atrial arrhythmia, all-cause death, stroke, and major bleeding. All meta-analyses were performed using the “meta” package in R with pooled incidence calculated using log transformation.

Results

Among 5,764 studies screened, 58 (n=41,344 patients) were included for analysis. The pooled mean age was 60.3y, 68.7% male, 78.4% paroxysmal AF, and radiofrequency was the most common ablation energy (72.4%). Most (51.5%) patients had hypertension, but the pooled rates of other comorbidities were low (heart failure: 9.0%, coronary artery disease: 12.8%, diabetes: 11.0%, and previous stroke: 8.5%). Pooled incidence of freedom from atrial arrhythmia at 5-years was 47.6% (95% CI 43.8%-51.6%, I2=98.4%) after a single procedure and increased to 64.3% (95% CI 59.6%-69.3%, I2=98.3%) after multiple procedures (Figure 1). The incidence was higher among patients with paroxysmal compared with non paroxysmal AF (55.9% vs. 28.7% and 82.2% vs. 47.6% after single and multiple procedures respectively). Retrospective studies reported slightly higher incidence of arrhythmia freedom (single procedure: 51.2% vs. 46.7%; multiple procedures: 66.9% vs. 61.9%) than did prospective studies. Few studies reported outcomes other than atrial arrhythmia free survival at 5-years (n=14) and incidences of these outcomes could only be pooled for multiple procedures. Pooled incidences of death, stroke, and major bleeding at 5-years were 8.0% (95% CI 4.2%-15.2%, I2=95.8%), 2.3% (95% CI 1.4%-3.6%, I2=72.9%), and 1.1% (95% CI 0.6%-1.8%, I2=32.5%), respectively (Figure 2).

Conclusion

At five-years, only up to 65% of patients undergoing AF ablations remained free from atrial arrhythmia although there was significant heterogeneity among individual studies. Encouragingly, these patients had low risk of dying, experiencing a stroke or major bleeding (all incidences&lt;10%).

Funding Acknowledgement

Type of funding sources: None.

A murine model of hereditary pulmonary alveolar proteinosis caused by homozygous Csf2ra gene disruption

Hereditary pulmonary alveolar proteinosis (hPAP) is a rare disorder caused by recessive mutations in GM-CSF receptor subunit α/β genes (CSF2RA/CSF2RB, respectively) characterized by impaired GM-CSF-dependent surfactant clearance by alveolar macrophages (AMs) resulting in alveolar surfactant accumulation and hypoxemic respiratory failure. Because hPAP is caused by CSF2RA mutations in most patients, we created an animal model of hPAP caused by Csf2ra gene disruption (Csf2ra^-/- mice) and evaluated the effects on AMs and lungs. Macrophages from Csf2ra^-/- mice were unable to bind and clear GM-CSF, did not exhibit GM-CSF signaling, and had functional defects in phagocytosis, cholesterol clearance, and surfactant clearance. Csf2ra^-/- mice developed a time-dependent, progressive lung disease similar to hPAP in children caused by CSF2RA mutations with respect to the clinical, physiological, histopathological, biochemical abnormalities, biomarkers of PAP lung disease, and clinical course. In contrast, Csf2ra^+/- mice had functionally normal AMs and no lung disease. Pulmonary macrophage transplantation (PMT) without myeloablation resulted in long-term engraftment, restoration of GM-CSF responsiveness to AMs, and a safe and durable treatment effect that lasted for the duration of the experiment (6 mo). Results demonstrate that homozygous (but not heterozygous) Csf2ra gene ablation caused hPAP identical to hPAP in children with CSF2RA mutations, identified AMs as the cellular site of hPAP pathogenesis in Csf2ra^-/- mice, and have implications for preclinical studies supporting the translation of PMT as therapy of hPAP in humans.

Proton emission study as a guide to astrophysical rp process

Proton emitters play an important role in deciding the path of the astrophysical rapid proton capture (rp) process. The lifetime of these nuclei depends on several factors, like the deformation, angular momentum of the emitted proton, residual interaction between valence proton and neutron (especially in case of odd-odd nuclei) and so on. Therefore, it is worth to investigate the structure of proton emitters to understand the rp process path. However, due to lack of data in this exotic region, the theoretical models should be robust and the dependence on the free parameters should be minimal. In this direction, we have developed the first microscopic approach to study the triaxially deformed odd-odd proton emitters. The application of the developed approach to 108I, a recently observed proton emitter to investigate the end cycle of the rp process, is discussed.

Role of GM-CSF in regulating metabolism and mitochondrial functions critical to macrophage proliferation

Granulocyte-macrophage colony-stimulating factor (GM-CSF) exerts pleiotropic effects on macrophages and is required for self-renewal but the mechanisms responsible are unknown. Using mouse models with disrupted GM-CSF signaling, we show GM-CSF is critical for mitochondrial turnover, functions, and integrity. GM-CSF signaling is essential for fatty acid β-oxidation and markedly increased tricarboxylic acid cycle activity, oxidative phosphorylation, and ATP production. GM-CSF also regulated cytosolic pathways including glycolysis, pentose phosphate pathway, and amino acid synthesis. We conclude that GM-CSF regulates macrophages in part through a critical role in maintaining mitochondria, which are necessary for cellular metabolism as well as proliferation and self-renewal.

Prognostic value of pericoronary adipose tissue and coronary vascular function by cardiac 82Rb PET/CT imaging in patients with suspected coronary artery disease and normal myocardial perfusion imaging

Funding Acknowledgements

Type of funding sources: None.

Introduction

Pericoronary adipose tissue, due to its proximity to coronary arteries, has been proposed contribute to the progression of coronary atherosclerosis.

Purpose

The aim of this study was to evaluate the prognostic value of pericoronary fat thickness (PCFT), coronary artery calcium (CAC) score and myocardial perfusion reserve (MPR) by hybrid 82Rubidium (82Rb) PET/CT imaging in patients with suspected coronary artery disease (CAD) and normal myocardial perfusion imaging (MPI).

Methods

A total of 640 patients without overt CAD and with normal rest-stress 82Rb PET/CT MPI were studied. PCFT was calculated on CT images as the maximum fat thickness (mm) between heart surface and visceral epicardium surrounding the main coronary arteries. CAC score was categorized as 0, &lt;400 or ≥400. MPR was considered reduced when &lt;2. Endpoints events were cardiac death, nonfatal myocardial infarction and coronary revascularization.

Results

During a follow-up of 42 ± 13 months, 29 events occurred (cumulative event rate 5%). Patients with events were older (66 ± 13 vs. 60 ± 13 years, p &lt; 0.01), had higher PCFT (13 ± 2 vs 11 ± 2 mm, p &lt; 0.001), higher prevalence of CAC score ≥400 (48% vs. 21%, p &lt; 0.01), and lower MPR (2.1 ± 0.7 vs. 2.7 ± 0.7, p &lt; 0.001) compared to those without. A higher prevalence of MPR &lt;2 was observed in patients with events (48% vs. 18, p &lt; 0.001) compared to those without. Patients with reduced MPR had higher PCFT compared to those with normal MPR (12 ± 2 vs. 11 ± 1 mm, p &lt; 0.01). A PCFT value of 11.2 mm was the best trade-off between sensitivity and specificity to detect a reduced MPR. Event rate was higher in patients above this threshold compared to those below (8% vs. 1.5%, p &lt; 0.001). At Cox univariate analysis, age (p &lt; 0.05), PCFT &gt;11.2 mm (p &lt; 0.001), CAC score ≥400 (p &lt; 0.01), and MPR &lt;2 (p &lt; 0.001) were predictors of events. At multivariate analysis, only PCFT &gt;11.2 mm and MPR &lt;2 were independent predictors of events (both p &lt; 0.01). At incremental analysis, adding PCFT &gt;11.2 to a model including clinical data and MPR &lt;2 increased the global chi-square from 26 to 35 (p &lt; 0.01). Classification tree analysis produced 3 terminal groups. For patients with MPR &lt;2, no further split was needed (event rate 12% vs. 3%, p &lt; 0.001). On the contrary, patients with MPR ≥2 were further stratified by PCFT (event rate 7% in patients with and 0.3% in those without (p &lt; 0.001) PCFT &gt;11.2.

Conclusions

In patients with suspected CAD and normal stress MPI, coronary vascular dysfunction and high PCFT are associated with increased cardiac risk. PCFT could help in identifying patients at higher risk of events. Combined evaluation of anatomical and functional vascular abnormalities by 82Rb PET/CT might allow a better risk stratification.

Thrombin-PAR1 signaling in pancreatic cancer promotes an immunosuppressive microenvironment

Essentials Elimination of PDAC tumor cell PAR1 increased cytotoxic T cells and reduced tumor macrophages. PAR1KO PDAC cells are preferentially eliminated from growing tumors. Thrombin-PAR1 signaling in PDAC tumor cells drives an immunosuppressive gene signature. Csf2 and Ptgs2 are thrombin-PAR1 downstream immune suppressor genes in PDAC tumor cells. ABSTRACT: Background Pancreatic ductal adenocarcinoma (PDAC) is characterized by a prothrombotic state and a lack of host antitumor immune responsiveness. Linking these two key features, we previously demonstrated that tumor-derived coagulation activity promotes immune evasion. Specifically, thrombin-protease-activated receptor-1 (PAR1) signaling in mouse PDAC cells drives tumor growth by evading cytotoxic CD8a+ cells. Methods Syngeneic mixed cell tumor growth, transcriptional analyses, and functional tests of immunosuppressive response genes were used to identify cellular and molecular immune evasion mechanisms mediated by thrombin-PAR-1 signaling in mouse PDAC tumor cells. Results Elimination of tumor cell PAR1 in syngeneic graft studies increased cytotoxic T lymphocyte (CTL) infiltration and decreased tumor-associated macrophages in the tumor microenvironment. Co-injection of PAR1-expressing and PAR1-knockout (PAR-1KO ) tumor cells into immunocompetent mice resulted in preferential elimination of PAR-1KO cells from developing tumors, suggesting that PAR1-dependent immune evasion is not reliant on CTL exclusion. Transcriptomics analyses revealed no PAR1-dependent changes in the expression of immune checkpoint proteins and no difference in major histocompatibility complex-I cell surface expression. Importantly, thrombin-PAR1 signaling in PDAC cells upregulated genes linked to immunosuppression, including Csf2 and Ptgs2. Functional analyses confirmed that both Csf2 and Ptgs2 are critical for PDAC syngeneic graft tumor growth and overexpression of each factor partially restored tumor growth of PAR1KO cells in immunocompetent mice. Conclusions Our results provide novel insight into the mechanisms of a previously unrecognized pathway coupling coagulation to PDAC immune evasion by identifying PAR1-dependent changes in the tumor microenvironment, a PAR1-driven immunosuppressive gene signature, and Csf2 and Ptgs2 as critical PAR1 downstream targets.

FOXM1 nuclear transcription factor translocates into mitochondria and inhibits oxidative phosphorylation

Forkhead box M1 (FOXM1), a nuclear transcription factor that activates cell cycle regulatory genes, is highly expressed in a majority of human cancers. The function of FOXM1 independent of nuclear transcription is unknown. In the present study, we found the FOXM1 protein inside the mitochondria. Using site-directed mutagenesis, we generated FOXM1 mutant proteins that localized to distinct cellular compartments, uncoupling the nuclear and mitochondrial functions of FOXM1. Directing FOXM1 into the mitochondria decreased mitochondrial mass, membrane potential, respiration, and electron transport chain (ETC) activity. In mitochondria, the FOXM1 directly bound to and increased the pentatricopeptide repeat domain 1 (PTCD1) protein, a mitochondrial leucine-specific tRNA binding protein that inhibits leucine-rich ETC complexes. Mitochondrial FOXM1 did not change cellular proliferation. Thus, FOXM1 translocates into mitochondria and inhibits mitochondrial respiration by increasing PTCD1. We identify a new paradigm that FOXM1 regulates mitochondrial homeostasis in a process independent of nuclear transcription.

Neutrophil extracellular traps activate IL-8 and IL-1 expression in human bronchial epithelia

Neutrophil extracellular traps (NETs) provide host defense but can contribute to the pathobiology of diverse human diseases. We sought to determine the extent and mechanism by which NETs contribute to human airway cell inflammation. Primary normal human bronchial epithelial cells (HBEs) grown at air-liquid interface and wild-type (wt)CFBE41o- cells (expressing wtCFTR) were exposed to cell-free NETs from unrelated healthy volunteers for 18 h in vitro. Cytokines were measured in the apical supernatant by Luminex, and the effect on the HBE transcriptome was assessed by RNA sequencing. NETs consistently stimulated IL-8, TNF-α, and IL-1α secretion by HBEs from multiple donors, with variable effects on other cytokines (IL-6, G-CSF, and GM-CSF). Expression of HBE RNAs encoding IL-1 family cytokines, particularly IL-36 subfamily members, was increased in response to NETs. NET exposure in the presence of anakinra [recombinant human IL-1 receptor antagonist (rhIL-1RA)] dampened NET-induced changes in IL-8 and TNF-α proteins as well as IL-36α RNA. rhIL-36RA limited the increase in expression of proinflammatory cytokine RNAs in HBEs exposed to NETs. NETs selectively upregulate an IL-1 family cytokine response in HBEs, which enhances IL-8 production and is limited by rhIL-1RA. The present findings describe a unique mechanism by which NETs may contribute to inflammation in human lung disease in vivo. NET-driven IL-1 signaling may represent a novel target for modulating inflammation in diseases characterized by a substantial NET burden.

Abstract P1-14-06: Selective internal radiation therapy (SIRT) with Yttrium-90 resin microspheres and FOLFOX/5FU chemotherapy in pre-treated breast cancer patients with liver metastases: A retrospective analysis of response rates, times to progression and survival of patients treated in Manchester UK between 2010 and 2016

Background:

SIRT is a globally licensed technique of Radio-Embolization (RE) of hepatic tumors via intra-arterial infusion of β-particle emitting Yttrium-90 (Y-90) radio-labelled microspheres. It increases response rates and hepatic time to progression in metastatic colorectal cancer when used in combination with 5FU/Oxaliplatin (FOLFOX) chemotherapy with acceptable toxicity profile. FOLFOX gives a radio-sensitizing effect and also controls disease outside the liver. Breast cancer liver metastases (BCLM) patients often have extra-hepatic disease and respond to multiple lines of systemic therapy and SIRT is infrequently used.

Methods and patients

Between 2010 and 2016 we treated 25 BCLM patients with Y-90 SIRT.

Receptor status: 20 ER+ve/HER-2 -ve, 3 ER-ve/HER-2 +ve, 2 triple -ve.

Eleven patients had liver only disease with 14 also having known extra-hepatic disease. Average number of previous lines of therapy in metastatic setting: chemotherapy = 2.4; endocrine = 1. Sixty-four % patients had prior Capecitabine (n=16); 12% platinum (n=3, all Carboplatin). Twenty patients received chemotherapy with SIRT: 17 had modified FOLFOX6 (Oxaliplatin/bolus 5FU day1, infusional 5FU day 1-3 (46 hrs); 3 patients had Modified de Gramont style 5FU alone. Five patients had no chemotherapy.

Sir-spheres were inserted on day 2 of FOLFOX with the 5FU infusion pump continuing to day 3. Further 2-weekly FOLFOX chemo cycles were at clinician's discretion: average number delivered 3.8. Four patients had the liver treated in two halves, approximately 6 weeks apart. One patient received SIRT only to half the liver. Patients were imaged with PET-CT/CT before and 2-3 months after SIRT. Retrospective case note review was performed and data correlated to evaluate tumor response (RR); hepatic and extra hepatic progression free survival (HPFS and EHPFS) and overall survival (OS). Accurate toxicity data was not recorded.

Results

Hepatic CT response rates: PR 56% (n=14), SD 28% (n=7) and PD 16% (n=4). Hepatic PET response rates: CR 32% (n=8), PR 40% (n=10), SD 12% (n=3), PD 16%(n=4). (Overall PET liver disease control rate = 84%).

Eight patients (32%) had extra-hepatic PD at first assessment. Of them, 4 had PR, 2 SD and 2 PD in the liver at that assessment. Two HER-2 +ve patients had brain metastases as first sign of PD within 75 days, an area not previously screened. Of 16 pre-treated with Capecitabine, liver CT response rates: 62.5% PR, 18.75% SD (n=10,3). Post SIRT/FOLFOX, average number of therapy lines: 2 for chemo and 0.75 for endocrine, with 8 patients still alive at time of censoring.

Median OS: 766 HPFS: 210 days (CI 140-286). Median EHPFS in patients with extra-hepatic disease: 152 days (CI 96-636).

Conclusions

SIRT with FOLFOX in previously treated BCLM patients produces high response rates, excellent tumor control and time to progression in the liver with good overall survival. It does not seem to decrease the ability to give further lines of chemotherapy and can be considered as an option for breast cancer patients with liver metastases.

Citation Format: Wilson G, Mullamitha S, Bentley D, Bell J, Mullan D, Carter L, Chittalia A, Howell S, Laasch H-U, Westwood T, Jeans S, Tipping J, Ryder D, Farquharson F, Arumugam P, Sheen A, Rajashanker B, Armstrong A, Misra V, Manoharan P, Lawrance J. Selective internal radiation therapy (SIRT) with Yttrium-90 resin microspheres and FOLFOX/5FU chemotherapy in pre-treated breast cancer patients with liver metastases: A retrospective analysis of response rates, times to progression and survival of patients treated in Manchester UK between 2010 and 2016 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-14-06.

Function and Safety of Lentivirus-Mediated Gene Transfer for CSF2RA-Deficiency

Hereditary pulmonary alveolar proteinosis (hPAP) is a rare disorder of pulmonary surfactant accumulation and hypoxemic respiratory failure caused by mutations in CSF2RA (encoding the granulocyte/macrophage colony-stimulating factor [GM-CSF] receptor α-chain [CD116]), which results in reduced GM-CSF-dependent pulmonary surfactant clearance by alveolar macrophages. While no pharmacologic therapy currently exists for hPAP, it was recently demonstrated that endotracheal instillation of wild-type or gene-corrected mononuclear phagocytes (pulmonary macrophage transplantation [PMT]) results in a significant and durable therapeutic efficacy in a validated murine model of hPAP. To facilitate the translation of PMT therapy to human hPAP patients, a self-inactivating (SIN) lentiviral vector was generated expressing a codon-optimized human CSF2RA-cDNA driven from an EF1α short promoter (Lv.EFS.CSF2RA^coop), and a series of nonclinical efficacy and safety studies were performed in cultured macrophage cell lines and primary human cells. Studies in cytokine-dependent Ba/F3 cells demonstrated efficient transduction, vector-derived CD116 expression proportional to vector copy number, and GM-CSF-dependent cell survival and proliferation. Using a novel cell line constructed to express a normal GM-CSF receptor β subunit and a dysfunctional α subunit (due to a function-altering CSF2RA^G196R mutation) that reflects the macrophage disease phenotype of hPAP patients, it was demonstrated that Lv.EFS.CSF2RA^coop transduction restored GM-CSF receptor function. Further, Lv.EFS.CSF2RA^coop transduction of healthy primary CD34⁺ cells did not adversely affect cell proliferation or affect the cell differentiation program. Results demonstrate Lv.EFS.CSF2RA^coop reconstituted GM-CSF receptor α expression, restoring GM-CSF signaling in hPAP macrophages, and had no adverse effects in the intended target cells, thus supporting testing of PMT therapy of hPAP in humans.

The prevalence of secretor status and co-expression of lewis antigen in voluntary blood donors

Background: Blood group substances are present in soluble form in a majority of individuals in secretion such as saliva and body fl uids. Secretor status refers to the presence (SeSe and Sese) or absence (sese) of secretor gene which secrete ABH soluble substances. Secretor status can be used to resolve ABO discrepancies of people whose blood group cannot be identified by routine blood grouping and it can also help in identifying patients who may be a high risk group for getting certain diseases. Aims and Objectives:Our aim and objectives of the study is to fi nd out the Prevalence of Secretor Status and Co-expression of Lewis Antigens among the Voluntary Blood Donors.Materials and Methods:This study was conducted in sixty volunteers and the method used to determine the secretor status was hemagglutination inhibition method. Their blood was used to detect the type of Lewis (Le) antigen since the type of Lewis antigen correlated with the secretor status of the individual.Results:Among the sixty subjects tested, forty fi ve of them were found to be secretors and fifteen of them were Non-secretors. The number of Lewis (a+b-) individuals were twelve, Lewis (a-b+) were thirty nine and Lewis (a-b-) were nine.Conclusion:The prevalence of secretors was 75% and non-secretors were 25% respectively. We found 65 % of the volunteers were found to be Le (a-b+) positive, 20% were Le (a+b-) and the remaining 15% were Le (a-b-) which correlated with the ABH antigen secretor status.Asian Journal of Medical Sciences Vol.7(5) 2016 93-96

High Level of Perforin Expression Is Required for Effective Correction of Hemophagocytic Lymphohistiocytosis

Perforin-1 mutations result in a potentially fatal hemophagocytic lymphohistiocytosis (HLH) with heightened immune activation, hypercytokinemia, pancytopenia, and end-organ damage. At present, hematopoietic stem cell (HSC) transplantation is curative, but limited by donor availability and associated mortality, making gene therapy an attractive alternative approach for HLH. We reported that perforin expression driven by cellular promoters in lentiviral (LV) vectors resulted in significant, albeit partial, correction of the inflammatory features in a murine model of HLH. We hypothesized that the level of perforin expression achieved per cell from ectopic moderate-strength cellular promoters (phosphoglycerate kinase gene/perforin-1 gene) is inadequate and thus engineered an LV vector using a viral promoter (MND; a modified Moloney murine leukemia virus long terminal repeat with myeloproliferative sarcoma virus enhancer) containing microRNA126 target sequences to restrict perforin expression in HSCs. We show here that the MND-LV vector restored perforin expression to normal levels in a perforin-deficient human natural killer cell line and perforin gene-corrected Perforin1^-/- transplant recipients, whereas cellular promoters drove only partial correction. On lymphocytic choriomeningitis virus challenge, the clinical scores and survival improved only with the MND-LV vector, but inflammatory markers and cytotoxicity were improved with all LV vectors. Our studies suggest that although moderate levels of expression can result in partial amelioration of the HLH phenotype, high levels of perforin expression per cell are required for complete correction of HLH.

Individuals with impaired glucose tolerance demonstrate normal cardiac sympathetic innervation using I-123 mIBG scintigraphy

BACKGROUND

Impaired glucose tolerance (IGT) is associated with an increased risk of type 2 diabetes (T2DM) and cardiovascular disease. Some but not all studies have reported cardiac autonomic dysfunction in subjects with IGT and there is only one direct study of cardiac innervation in subjects with IGT. The purpose of this study was to assess global and regional cardiac sympathetic innervation and cardiac autonomic function in individuals with IGT.

METHODS AND RESULTS

We undertook (123)I-mIBG scintigraphy and cardiac autonomic function in 15 subjects with IGT and 15 age and sex-matched healthy controls. Early heart to mediastinum ratio (HMR) (1.71 ± 0.17 vs 1.67 ± 0.13, P = .49), late HMR (1.73 ± 0.18 vs 1.73 ± 0.16, P = .97) and washout rate (WR) (18.6 ± 4.2 vs 19.1 ± 7.6%, P = .84), did not differ between subjects with IGT and control subjects. More detailed regional analysis revealed reduced tracer uptake at the apex, base and inferior wall in all subjects and the anterior wall in a minority of subjects. There were no differences in total score (56.6 ± 4.0 vs 53.3 ± 8.4, P = .193), modified score (48.5 ± 3.3 vs 46.2 ± 6.0, P = .215), anterior wall score (10.2 ± 1.3 vs 10.1 ± 1.6, P = .898), inferior wall score (8.9 ± 1.9 vs 7.7 ± 2.6, P = .163), basal score (18.7 ± 1.9 vs 18.2 ± 3.3, P = .636) and tests of cardiac autonomic function between the groups.

CONCLUSION

Global and regional measures of MIBG uptake and washout as well as cardiac autonomic function did not differ between subjects with IGT and healthy controls.

Looking outside the "cardiac" box: incidental detection of a metastatic lung tumor on cardiac position emission tomography/computed tomography

Incidental extracardiac findings are not uncommon in patients undergoing cardiac positron emission tomography/computed tomography (PET/CT) and some of these findings can have significant clinical impact. We report a case of a 74-year-old man who presented with dyspnea and left sided chest pain. 82-rubidium PET/CT imaging showed normal myocardial perfusion. Review of the low dose CT scan performed for attenuation correction purposes (CTAC) incidentally revealed a 4 cm mass in the left lung, which was histologically shown to be a squamous cell carcinoma. A subsequent staging CT showed chest wall metastases and rib destruction in the upper left thorax, which were outside the image reconstruction field of view of the CTAC. This report illustrates the importance of vigilant review of all acquired images by the PET/CT reader to look for extracardiac abnormalities that may explain symptoms in the absence of coronary artery disease. It also raises the question as to whether a larger field of CT image acquisition should be routinely performed to scan the entire chest during cardiac PET/CT imaging. However, the latter needs to be weighed against the increase in patient dose, which we estimated to be an additional 15%.

Pulmonary macrophage transplantation therapy

Bone marrow transplantation is an effective cell therapy but requires myeloablation, which increases infection-risk and mortality. Recent lineage-tracing studies documenting that resident macrophage populations self-maintain independent of hematologic progenitors prompted us to consider organ-targeted, cell-specific therapy. Here, using GM-CSF receptor-β deficient (Csf2rb^−/−) mice that develop a myeloid cell disorder identical to hereditary pulmonary alveolar proteinosis (hPAP) in children with CSF2RA/CSF2RB mutations, we show that pulmonary macrophage transplantation (PMT) of either wild-type or Csf2rb-gene-corrected macrophages without myeloablation was safe, well-tolerated, and that one administration corrected the lung disease, secondary systemic manifestations, normalized disease-related biomarkers, and prevented disease-specific mortality. PMT-derived alveolar macrophages persisted for at least one year as did therapeutic effects. Results identify mechanisms regulating alveolar macrophage population size in health and disease, indicate that GM-CSF is required for phenotypic determination of alveolar macrophages, and support translation of PMT as the first specific therapy for children with hPAP.

MELAS syndrome presenting as an acute surgical abdomen

MELAS (mitochondrial cytopathy, encephalomyopathy, lactic acidosis and stroke-like episodes) is a syndrome in which signs and symptoms of gastrointestinal disease are uncommon if not rare. We describe the case of a young woman who presented as an acute surgical emergency, diagnosed as toxic megacolon necessitating an emergency total colectomy. MELAS syndrome was suspected postoperatively owing to persistent lactic acidosis and neurological symptoms. The diagnosis was later confirmed with histological and genetic studies. This case highlights the difficulties in diagnosing MELAS because of its unpredictable presentation and clinical course. We therefore recommend a high index of suspicion in cases of an acute surgical abdomen with additional neurological features or raised lactate.

RhoA GTPase controls cytokinesis and programmed necrosis of hematopoietic progenitors

The GTPase RhoA is required for the appropriate division and survival of hematopoietic progenitor cells.

Hematopoietic progenitor cells (HPCs) are central to hematopoiesis as they provide large numbers of lineage-defined blood cells necessary to sustain blood homeostasis. They are one of the most actively cycling somatic cells, and their precise control is critical for hematopoietic homeostasis. The small GTPase RhoA is an intracellular molecular switch that integrates cytokine, chemokine, and adhesion signals to coordinate multiple context-dependent cellular processes. By using a RhoA conditional knockout mouse model, we show that RhoA deficiency causes a multilineage hematopoietic failure that is associated with defective multipotent HPCs. Interestingly, RhoA^−/− hematopoietic stem cells retained long-term engraftment potential but failed to produce multipotent HPCs and lineage-defined blood cells. This multilineage hematopoietic failure was rescued by reconstituting wild-type RhoA into the RhoA^−/− Lin⁻Sca-1⁺c-Kit⁺ compartment. Mechanistically, RhoA regulates actomyosin signaling, cytokinesis, and programmed necrosis of the HPCs, and loss of RhoA results in a cytokinesis failure of HPCs manifested by an accumulation of multinucleated cells caused by failed abscission of the cleavage furrow after telophase. Concomitantly, the HPCs show a drastically increased death associated with increased TNF–RIP-mediated necrosis. These results show that RhoA is a critical and specific regulator of multipotent HPCs during cytokinesis and thus essential for multilineage hematopoiesis.

Prevalence of biofilm-producing Staphylococcus epidermidis in the healthy skin of individuals in Tamil Nadu, India

PURPOSE

Staphylococcus epidermidis is a major commensal bacteria. Various strains of S. epidermidis are capable of forming biofilms by attaching to several surfaces. Biofilm-forming ability of this organism is found to be associated with many hospital-acquired infections and can even impair wound healing. S. epidermidis strains producing polysaccharide-biofilms possess the intercellular adhesion (ica) operon while strains forming the protein adhesion-mediated biofilms possess the accumulation associated protein (aap) gene. We screened for biofilm-forming S. epidermidis in the skin of healthy individuals in Tamil Nadu in order to determine the risk of acquiring S. epidermidis infections in hospital settings.

MATERIALS AND METHODS

Skin swabs were taken from seventy two subjects residing in Chennai with healthy skin who showed no visible signs of skin lesions or allergies. S. epidermidis was isolated from 58 samples out of the 72 collected. The presence of ica operon in S. epidermidis isolates was determined by PCR and biofilm production was examined using quantitative tissue culture plate assay.

RESULTS

Majority of the samples (47/72; 65.3%) showed pure S. epidermidis growth, (14/72; 19.4%) showed pure Staphylococcus aureus growth and the remainder (11/72; 15.3%) showed mixed growth. Biofilm-forming S. epidermidis were found in the majority of samples (53/58; 91.4%) and ica operon was detected in 19 samples out of 58 (32.8%) which is a significantly higher percentage when compared to other studies conducted at different parts of the globe ( P = 0.0003).

CONCLUSION

We inferred that ica operon and biofilm-forming S. epidermidis are common in the healthy skin of individuals in Tamil Nadu. Measures have to be taken to reduce the risk of hospital-acquired S. epidermidis infections.

Antimutagenic and Antiapoptotic Effects of Aqueous Root Extract of Inula racemosa Hook. f. on 4-NQO-Induced Genetic Damage in Mice

The present study was performed as part of an attempt to authenticate the use of Inula racemosa root extract as traditional medicine in India by experimentally investigating their protective effects on 4-nitroquinoline-1-oxide (4-NQO) induced DNA damage and apoptosis in mice bone marrow cells. Aqueous root extract (ARE) of Inula racemosa (100, 200 and 400 mg/kg bw) with and without 4-NQO along with vehicle control (H2O) were administered orally for five consecutive days. 4-NQO (7.5 mg/kg bw) was injected intraperitoneally to the mice on the sixth day. After 24 h, the animals were sacrificed and extracted bone marrow cells were used for micronuclei and apoptotic analysis. Antiapoptotic effect of ARE (400 mg/kg bw) was measured by the use of Annexin V-FITC assay kit. 4-NQO generated the frequency of micronucleated polychromatic erythrocytes (MnPCEs) by about 4.7 times the control value, 14.29 MnPCEs/2500 PCEs. Pretreatment with ARE significantly reduced the MnPCEs frequency (39-72%) with respect to their doses, and increased PCEs/NCEs ratio was observed over the 4-NQO alone. 4-NQO-induced total apoptotic cells were about 12% over the control which was significantly (P < 0.05) brought down to 3.5% by pretreatment with 400 mg/kg bw of ARE. This was the first report that recorded the protective effects of I. racemosa on 4-NQO-induced DNA damage and apoptosis in mice bone marrow cells.

Genetic therapy for beta-thalassemia: from the bench to the bedside

Beta-thalassemia is a genetic disorder with mutations in the β-globin gene that reduce or abolish β-globin protein production. Patients with β-thalassemia major (Cooley's anemia) become severely anemic by 6 to 18 months of age, and are transfusion dependent for life, while those with thalassemia intermedia, a less-severe form of thalassemia, are intermittently or rarely transfused. An allogeneically matched bone marrow transplant is curative, although it is restricted to those with matched donors. Gene therapy holds the promise of "fixing" one's own bone marrow cells by transferring the normal β-globin or γ-globin gene into hematopoietic stem cells (HSCs) to permanently produce normal red blood cells. Requirements for effective gene transfer for the treatment of β-thalassemia are regulated, erythroid-specific, consistent, and high-level β-globin or γ-globin expression. Gamma retroviral vectors have had great success with immune-deficiency disorders, but due to vector-associated limitations, they have limited utility in hemoglobinopathies. Lentivirus vectors, on the other hand, have now been shown in several studies to correct mouse and animal models of thalassemia. The immediate challenges of the field as it moves toward clinical trials are to optimize gene transfer and engraftment of a high proportion of genetically modified HSCs and to minimize the adverse consequences that can result from random integration of vectors into the genome by improving current vector design or developing novel vectors. This article discusses the current state of the art in gene therapy for β-thalassemia and some of the challenges it faces in human trials.