Anti-cancer pro-inflammatory effects of an IgE antibody targeting the melanoma-associated antigen chondroitin sulfate proteoglycan 4

Outcomes for half of patients with melanoma remain poor despite standard-of-care checkpoint inhibitor therapies. The prevalence of the melanoma-associated antigen chondroitin sulfate proteoglycan 4 (CSPG4) expression is ~70%, therefore effective immunotherapies directed at CSPG4 could benefit many patients. Since IgE exerts potent immune-activating functions in tissues, we engineer a monoclonal IgE antibody with human constant domains recognizing CSPG4 to target melanoma. CSPG4 IgE binds to human melanomas including metastases, mediates tumoricidal antibody-dependent cellular cytotoxicity and stimulates human IgE Fc-receptor-expressing monocytes towards pro-inflammatory phenotypes. IgE demonstrates anti-tumor activity in human melanoma xenograft models engrafted with human effector cells and is associated with enhanced macrophage infiltration, enriched monocyte and macrophage gene signatures and pro-inflammatory signaling pathways in the tumor microenvironment. IgE prolongs the survival of patient-derived xenograft-bearing mice reconstituted with autologous immune cells. No ex vivo activation of basophils in patient blood is measured in the presence of CSPG4 IgE. Our findings support a promising IgE-based immunotherapy for melanoma.

COVID-19 Detection Using Photoplethysmography and Neural Networks

The early identification of microvascular changes in patients with Coronavirus Disease 2019 (COVID-19) may offer an important clinical opportunity. This study aimed to define a method, based on deep learning approaches, for the identification of COVID-19 patients from the analysis of the raw PPG signal, acquired with a pulse oximeter. To develop the method, we acquired the PPG signal of 93 COVID-19 patients and 90 healthy control subjects using a finger pulse oximeter. To select the good quality portions of the signal, we developed a template-matching method that excludes samples corrupted by noise or motion artefacts. These samples were subsequently used to develop a custom convolutional neural network model. The model accepts PPG signal segments as input and performs a binary classification between COVID-19 and control samples. The proposed model showed good performance in identifying COVID-19 patients, achieving 83.86% accuracy and 84.30% sensitivity (hold-out validation) on test data. The obtained results indicate that photoplethysmography may be a useful tool for microcirculation assessment and early recognition of SARS-CoV-2-induced microvascular changes. In addition, such a noninvasive and low-cost method is well suited for the development of a user-friendly system, potentially applicable even in resource-limited healthcare settings.

Search for Gamma-Ray Spectral Lines from Dark Matter Annihilation up to 100 TeV toward the Galactic Center with MAGIC

Linelike features in TeV γ rays constitute a "smoking gun" for TeV-scale particle dark matter and new physics. Probing the Galactic Center region with ground-based Cherenkov telescopes enables the search for TeV spectral features in immediate association with a dense dark matter reservoir at a sensitivity out of reach for satellite γ-ray detectors, and direct detection and collider experiments. We report on 223 hours of observations of the Galactic Center region with the MAGIC stereoscopic telescope system reaching γ-ray energies up to 100 TeV. We improved the sensitivity to spectral lines at high energies using large-zenith-angle observations and a novel background modeling method within a maximum-likelihood analysis in the energy domain. No linelike spectral feature is found in our analysis. Therefore, we constrain the cross section for dark matter annihilation into two photons to ⟨σv⟩≲5×10^{-28}  cm^{3} s^{-1} at 1 TeV and ⟨σv⟩≲1×10^{-25}  cm^{3} s^{-1} at 100 TeV, achieving the best limits to date for a dark matter mass above 20 TeV and a cuspy dark matter profile at the Galactic Center. Finally, we use the derived limits for both cuspy and cored dark matter profiles to constrain supersymmetric wino models.

Folate receptor alpha in ovarian cancer tissue and patient serum is associated with disease burden and treatment outcomes

BACKGROUND

Survival rates for ovarian cancer remain poor, and monitoring and prediction of therapeutic response may benefit from additional markers. Ovarian cancers frequently overexpress Folate Receptor alpha (FRα) and the soluble receptor (sFRα) is measurable in blood. Here we investigated sFRα as a potential biomarker.

METHODS

We evaluated sFRα longitudinally, before and during neo-adjuvant, adjuvant and palliative therapies, and tumour FRα expression status by immunohistrochemistry. The impact of free FRα on the efficacy of anti-FRα treatments was evaluated by an antibody-dependent cellular cytotoxicity assay.

RESULTS

Membrane and/or cytoplasmic FRα staining were observed in 52.7% tumours from 316 ovarian cancer patients with diverse histotypes. Circulating sFRα levels were significantly higher in patients, compared to healthy volunteers, specifically in patients sampled prior to neoadjuvant and palliative treatments. sFRα was associated with FRα cell membrane expression in the tumour. sFRα levels decreased alongside concurrent tumour burden in patients receiving standard therapies. High concentrations of sFRα partly reduced anti-FRα antibody tumour cell killing, an effect overcome by increased antibody doses.

CONCLUSIONS

sFRα may present a non-invasive marker for tumour FRα expression, with the potential for monitoring patient response to treatment. Larger, prospective studies should evaluate FRα for assessing disease burden and response to systemic treatments.

Classifying sepsis from photoplethysmography

Sepsis is a life-threatening organ dysfunction. It is caused by a dysregulated immune response to an infection and is one of the leading causes of death in the intensive care unit (ICU). Early detection and treatment of sepsis can increase the survival rate of patients. The use of devices such as the photoplethysmograph could allow the early evaluation in addition to continuous monitoring of septic patients. The aim of this study was to verify the possibility of detecting sepsis in patients from whom the photoplethysmographic signal was acquired via a pulse oximeter. In this work, we developed a deep learning-based model for sepsis identification. The model takes a single input, the photoplethysmographic signal acquired by pulse oximeter, and performs a binary classification between septic and nonseptic samples. To develop the method, we used MIMIC-III database, which contains data from ICU patients. Specifically, the selected dataset includes 85 septic subjects and 101 control subjects. The PPG signals acquired from these patients were segmented, processed and used as input for the developed model with the aim of identifying sepsis. The proposed method achieved an accuracy of 76.37% with a sensitivity of 70.95% and a specificity of 81.04% on the test set. As regards the ROC curve, the Area Under Curve reached a value of 0.842. The results of this study indicate how the plethysmographic signal can be used as a warning sign for the early detection of sepsis with the aim of reducing the time for diagnosis and therapeutic intervention. Furthermore, the proposed method is suitable for integration in continuous patient monitoring.

Detecting sepsis from photoplethysmography: strategies for dataset preparation

Sepsis is one of the most frequent causes of death in Intensive Care Units, and its prognosis greatly depend on timeliness of diagnosis. MIMIC-III database is a frequent source of data for developing method for automatic sepsis detection. However, the heterogeneity of data jeopardize the feasibility of the task. In this work we propose a selection strategy for generating high quality data suitable for training a sepsis detection system based on the utilization of only plethysmographic data. Clinical relevance A system for detecting sepsis based only on PPG may be potentially at virtually no cost in any case clinicians suspect the possibility of developing sepsis.

Immunotherapy using IgE or CAR T cells for cancers expressing the tumor antigen SLC3A2

Background

Cancer immunotherapy with monoclonal antibodies and chimeric antigen receptor (CAR) T cell therapies can benefit from selection of new targets with high levels of tumor specificity and from early assessments of efficacy and safety to derisk potential therapies.

Methods

Employing mass spectrometry, bioinformatics, immuno-mass spectrometry and CRISPR/Cas9 we identified the target of the tumor-specific SF-25 antibody. We engineered IgE and CAR T cell immunotherapies derived from the SF-25 clone and evaluated potential for cancer therapy.

Results

We identified the target of the SF-25 clone as the tumor-associated antigen SLC3A2, a cell surface protein with key roles in cancer metabolism. We generated IgE monoclonal antibody, and CAR T cell immunotherapies each recognizing SLC3A2. In concordance with preclinical and, more recently, clinical findings with the first-in-class IgE antibody MOv18 (recognizing the tumor-associated antigen Folate Receptor alpha), SF-25 IgE potentiated Fc-mediated effector functions against cancer cells in vitro and restricted human tumor xenograft growth in mice engrafted with human effector cells. The antibody did not trigger basophil activation in cancer patient blood ex vivo, suggesting failure to induce type I hypersensitivity, and supporting safe therapeutic administration. SLC3A2-specific CAR T cells demonstrated cytotoxicity against tumor cells, stimulated interferon-γ and interleukin-2 production in vitro. In vivo SLC3A2-specific CAR T cells significantly increased overall survival and reduced growth of subcutaneous PC3-LN3-luciferase xenografts. No weight loss, manifestations of cytokine release syndrome or graft-versus-host disease, were detected.

Conclusions

These findings identify efficacious and potentially safe tumor-targeting of SLC3A2 with novel immune-activating antibody and genetically modified cell therapies.

Improvising resilience: The unfolding of resilient leadership in COVID-19 times

The spread of the COVID-19 pandemic in Italy has had disastrous effects on the national economy. The hospitality sector has experienced a significant impact from the crisis: starting from March 2020 it has literally collapsed. Experts believe it will take three years for the sector to recover. Confronted with a dramatic uncertainty, which imposed rapid action, hospitality leaders need to nurture resilience. To enrich current understanding of the way resilient leadership unfolds to respond to jolts, we draw on an exploratory qualitative research involving Italian hotel managers. Following in-depth interviews, we show that resilient leadership and improvisation are deeply interconnected. Their interdependence entails two practices, namely gardening and learning. This suggests a paradoxical tension: to exercise resilience, leaders need to be at the same time in the system, by actively learning from events, and outside the system, by zooming out as they focus on ongoing planning for the next move.

A Novel Kindred with Familial Gastrointestinal Stromal Tumors Caused by a Rare KIT Germline Mutation (N655K): Clinico-Pathological Presentation and TKI Sensitivity

Gastrointestinal stromal tumors (GISTs), the most common mesenchymal tumors of the gastrointestinal tract, are characterized by activating mutations in KIT or PDGFRA genes. The vast majority of GISTs are sporadic, but rare hereditary forms have been reported, often featuring multifocality and younger age of onset. We here report the identification of a novel kindred affected by familial GIST caused by a KIT germline mutation in exon 13 (N655K). No family affected by hereditary GIST due to this KIT variant has been reported in literature so far. We were able to track the mutation in three members of the family (proband, mother, and second-degree cousin), all affected by multiple GISTs. Due to its rarity, the N655K variant is poorly characterized. We conducted in vitro drug sensitivity assays that indicated that most tyrosine kinase inhibitors (TKIs) currently included in the therapeutic armamentarium for GISTs have a limited inhibitory activity toward this mutation. However, when compared to a classical imatinib-resistant KIT mutation (T670I), N655K was slightly more sensitive to imatinib, and encouraging responses were observed with last-generation TKIs.

IgE Activates Monocytes from Cancer Patients to Acquire a Pro-Inflammatory Phenotype

IgE contributes to host-protective functions in parasitic and bacterial infections, often by monocyte and macrophage recruitment. We previously reported that monocytes contribute to tumour antigen-specific IgE-mediated tumour growth restriction in rodent models. Here, we investigate the impact of IgE stimulation on monocyte response, cellular signalling, secretory and tumour killing functions. IgE cross-linking on human monocytes with polyclonal antibodies to mimic formation of immune complexes induced upregulation of co-stimulatory (CD40, CD80, CD86), and reduced expression of regulatory (CD163, CD206, MerTK) monocyte markers. Cross-linking and tumour antigen-specific IgE antibody-dependent cellular cytotoxicity (ADCC) of cancer cells by cancer patient-derived monocytes triggered release of pro-inflammatory mediators (TNFα, MCP-1, IL-10, CXCL-10, IL-1β, IL-6, IL-23). High intratumoural gene expression of these mediators was associated with favourable five-year overall survival in ovarian cancer. IgE cross-linking of trimeric FcεRI on monocytes stimulated the phosphorylation of intracellular protein kinases widely reported to be downstream of mast cell and basophil tetrameric FcεRI signalling. These included recently-identified FcεRI pathway kinases Fgr, STAT5, Yes and Lck, which we now associate with monocytes. Overall, anti-tumour IgE can potentiate pro-inflammatory signals, and prime tumour cell killing by human monocytes. These findings will inform the development of IgE monoclonal antibody therapies for cancer.

Bounds on Lorentz Invariance Violation from MAGIC Observation of GRB 190114C

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

Basophils from Cancer Patients Respond to Immune Stimuli and Predict Clinical Outcome

Basophils are involved in manifestations of hypersensitivity, however, the current understanding of their propensity for activation and their prognostic value in cancer patients remains unclear. As in healthy and atopic individuals, basophil populations were identified in blood from ovarian cancer patients (n = 53) with diverse tumor histologies and treatment histories. Ex vivo basophil activation was measured by CD63 expression using the basophil activation test (BAT). Irrespective of prior treatment, basophils could be activated by stimulation with IgE- (anti-FcεRI and anti-IgE) and non-IgE (fMLP) mediated triggers. Basophil activation was detected by ex vivo exposure to paclitaxel, but not to other anti-cancer therapies, in agreement with a clinical history of systemic hypersensitivity reactions to paclitaxel. Protein and gene expression analyses support the presence of basophils (CCR3, CD123, FcεRI) and activated basophils (CD63, CD203c, tryptase) in ovarian tumors. Greater numbers of circulating basophils, cells with greater capacity for ex vivo stimulation (n = 35), and gene signatures indicating the presence of activated basophils in tumors (n = 439) were each associated with improved survival in ovarian cancer. Circulating basophils in cancer patients respond to IgE- and non-IgE-mediated signals and could help identify hypersensitivity to therapeutic agents. Activated circulating and tumor-infiltrating basophils may be potential biomarkers in oncology.

The chaperone-like sodium phenylbutyrate improves factor IX intracellular trafficking and activity impaired by the frequent p.R294Q mutation

Essentials Missense mutations often impair protein folding, and thus intracellular trafficking and secretion. Cellular models of severe type I hemophilia B were challenged with chaperone-like compounds. Sodium phenylbutyrate improved intracellular trafficking and secretion of the frequent p.R294Q. The increased coagulant activity levels (∼3%) of p.R294Q would ameliorate the bleeding phenotype.

SUMMARY

Background Missense mutations often impair protein folding and intracellular processing, which can be improved by small compounds with chaperone-like activity. However, little has been done in coagulopathies, where even modest increases of functional levels could have therapeutic implications. Objectives To rescue the expression of factor IX (FIX) variants affected by missense mutations associated with type I hemophilia B (HB) through chaperone-like compounds. Methods Expression studies of recombinant (r)FIX variants and evaluation of secreted levels (ELISA), intracellular trafficking (immunofluorescence) and activity (coagulant assays) before and after treatment of cells with chaperone-like compounds. Results As a model we chose the most frequent HB mutation (p.R294Q, ~100 patients), compared with other recurrent mutations associated with severe/moderate type I HB. Immunofluorescence studies revealed retention of rFIX variants in the endoplasmic reticulum and negligible localization in the Golgi, thus indicating impaired intracellular trafficking. Consistently, and in agreement with coagulation phenotypes in patients, all missense mutations resulted in impaired secretion (< 1% wild-type rFIX). Sodium phenylbutyrate (NaPBA) quantitatively improved trafficking to the Golgi and dose dependently promoted secretion (from 0.3 ± 0.1% to 1.5 ± 0.3%) only of the rFIX-294Q variant. Noticeably, this variant displayed a specific coagulant activity that was higher (~2.0 fold) than that of wild-type rFIX in all treatment conditions. Importantly, coagulant activity was concurrently increased to levels (3.0 ± 0.9%) that, if achieved in patients, would ameliorate the bleeding phenotype. Conclusions Altogether, our data detail molecular mechanisms underlying type I HB and candidate NaPBA as affordable 'personalized' therapeutics for patients affected by the highly frequent p.R294Q mutation, and with reduced access to substitutive therapy.

Metabolic control and complications in Italian people with diabetes treated with continuous subcutaneous insulin infusion

BACKGROUND AND AIM

The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII).

METHODS AND RESULTS

Questionnaires investigating the organisation of diabetes care centres, individuals' clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA_1c) level was 60 mmol/mol (7.6%). The HbA_1c target (i.e. <58 mmol/mol for age <18 years and <53 mmol/mol for age >18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA_1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis.

CONCLUSIONS

Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 02620917 (ClinicalTrials.gov).

Evaluation of Antigen-Conjugated Fluorescent Beads to Identify Antigen-Specific B Cells

Selection of single antigen-specific B cells to identify their expressed antibodies is of considerable interest for evaluating human immune responses. Here, we present a method to identify single antibody-expressing cells using antigen-conjugated fluorescent beads. To establish this, we selected Folate Receptor alpha (FRα) as a model antigen and a mouse B cell line, expressing both the soluble and the membrane-bound forms of a human/mouse chimeric antibody (MOv18 IgG1) specific for FRα, as test antibody-expressing cells. Beads were conjugated to FRα using streptavidin/avidin-biotin bridges and used to select single cells expressing the membrane-bound form of anti-FRα. Bead-bound cells were single cell-sorted and processed for single cell RNA retrotranscription and PCR to isolate antibody heavy and light chain variable regions. Variable regions were then cloned and expressed as human IgG1/k antibodies. Like the original clone, engineered antibodies from single cells recognized native FRα. To evaluate whether antigen-coated beads could identify specific antibody-expressing cells in mixed immune cell populations, human peripheral blood mononuclear cells (PBMCs) were spiked with test antibody-expressing cells. Antigen-specific cells could comprise up to 75% of cells selected with antigen-conjugated beads when the frequency of the antigen-positive cells was 1:100 or higher. In PBMC pools, beads conjugated to recombinant antigens FRα and HER2 bound antigen-specific anti-FRα MOv18 and anti-HER2 Trastuzumab antibody-expressing cells, respectively. From melanoma patient-derived B cells selected with melanoma cell line-derived protein-coated fluorescent beads, we generated a monoclonal antibody that recognized melanoma antigen-coated beads. This approach may be further developed to facilitate analysis of B cells and their antibody profiles at the single cell level and to help unravel humoral immune repertoires.

Nociceptin/orphanin FQ antagonizes lipopolysaccharide-stimulated proliferation, migration and inflammatory signaling in human glioblastoma U87 cells

Glioblastoma is among the most aggressive brain tumors and has an exceedingly poor prognosis. Recently, the importance of the tumor microenvironment in glioblastoma cell growth and progression has been emphasized. Toll-like receptor 4 (TLR4) recognizes bacterial lipopolysaccharide (LPS) and endogenous ligands originating from dying cells or the extracellular matrix involved in host defense and in inflammation. G-protein coupled receptors (GPCRs) have gained interest in anti-tumor drug discovery due to the role that they directly or indirectly play by transactivating other receptors, causing cell migration and proliferation. A proteomic analysis showed that the nociceptin receptor (NOPr) is among the GPCRs significantly expressed in glioblastoma cells, including U87 cells. We describe a novel role of the peptide nociceptin (N/OFQ), the endogenous ligand of the NOPr that counteracts cell migration, proliferation and increase in IL-1β mRNA elicited by LPS via TLR4 in U87 glioblastoma cells. Signaling pathways through which N/OFQ inhibits LPS-mediated cell migration and elevation of [Ca2+]i require β-arrestin 2 and are sensitive to TNFR-associated factor 6, c-Src and protein kinase C (PKC). LPS-induced cell proliferation and increase in IL-1β mRNA are counteracted by N/OFQ via β-arrestin 2, PKC and extracellular signal-regulated kinase 1/2; furthermore, the contributions of the transcription factors NF-kB and AP-1 were investigated. Independent of LPS, N/OFQ induces a significant increase in cell apoptosis. Contrary to what was observed in other cell models, a prolonged exposure to this endotoxin did not promote any tolerance of the cellular effects above described, including NOPr down-regulation while N/OFQ loses its inhibitory role.

Differential functional readthrough over homozygous nonsense mutations contributes to the bleeding phenotype in coagulation factor VII deficiency

Essentials Potentially null homozygous Factor(F)7 nonsense mutations are associated to variable bleeding symptoms. Readthrough of p.Ser112X (life-threatening) and p.Cys132X (moderate) stop codons was investigated. Readthrough-mediated insertion of wild-type or tolerated residues produce functional proteins. Functional readthrough over homozygous F7 nonsense mutations contributes to the bleeding phenotype.

SUMMARY

Background Whereas the rare homozygous nonsense mutations causing factor (F)VII deficiency may predict null conditions that are almost completely incompatible with life, they are associated with appreciable differences in hemorrhagic symptoms. The misrecognition of premature stop codons (readthrough) may account for variable levels of functional full-length proteins. Objectives To experimentally evaluate the basal and drug-induced levels of FVII resulting from the homozygous p.Cys132X and p.Ser112X nonsense mutations that are associated with moderate (132X) or life-threatening (112X) symptoms, and that are predicted to undergo readthrough with (132X) or without (112X) production of wild-type FVII. Methods We transiently expressed recombinant FVII (rFVII) nonsense and missense variants in human embryonic kidney 293 cells, and evaluated secreted FVII protein and functional levels by ELISA, activated FX generation, and coagulation assays. Results The levels of functional FVII produced by p.Cys132X and p.Ser112X mutants (rFVII-132X, 1.1% ± 0.2% of wild-type rFVII; rFVII-112X, 0.5% ± 0.1% of wild-type rFVII) were compatible with the occurrence of spontaneous readthrough, which was magnified by the addition of G418 - up to 12% of the wild-type value for the rFVII-132X nonsense variant. The predicted missense variants arising from readthrough abolished (rFVII-132Trp/Arg) or reduced (rFVII-112Trp/Cys/Arg, 22-45% of wild-type levels) secretion and function. These data suggest that the appreciable rescue of p.Cys132X function was driven by reinsertion of the wild-type residue, whereas the minimal p.Ser112X function was explained by missense changes permitting FVII secretion and function. Conclusions The extent of functional readthrough might explain differences in the bleeding phenotype of patients homozygous for F7 nonsense mutations, and prevent null conditions even for the most readthrough-unfavorable mutations.

A Blocking Group Scan Using a Spherical Organometallic Complex Identifies an Unprecedented Binding Mode with Potent Activity In Vitro and In Vivo for the Opioid Peptide Dermorphin

Herein, the selective enforcement of one particular receptor-ligand interaction between specific domains of the μ-selective opioid peptide dermorphin and the μ opioid receptor is presented. For this, a blocking group scan is described which exploits the steric demand of a bis(quinolinylmethyl)amine rhenium(I) tricarbonyl complex conjugated to a number of different, strategically chosen positions of dermorphin. The prepared peptide conjugates lead to the discovery of two different binding modes: An expected N-terminal binding mode corresponds to the established view of opioid peptide binding, whereas an unexpected C-terminal binding mode is newly discovered. Surprisingly, both binding modes provide high affinity and agonistic activity at the μ opioid receptor in vitro. Furthermore, the unprecedented C-terminal binding mode shows potent dose-dependent antinociception in vivo. Finally, in silico docking studies support receptor activation by both dermorphin binding modes and suggest a biological relevance for dermorphin itself. Relevant ligand-protein interactions are similar for both binding modes, which is in line with previous protein mutation studies.

IgG subclass switching and clonal expansion in cutaneous melanoma and normal skin

B cells participate in immune surveillance in human circulation and tissues, including tumors such as melanoma. By contrast, the role of humoral responses in cutaneous immunity is underappreciated. We report circulating skin-homing CD22+CLA+B cells in healthy volunteers and melanoma patients (n = 73) and CD22+ cells in melanoma and normal skin samples (n = 189). Normal and malignant skin featured mature IgG and CD22 mRNA, alongside mRNA for the transiently-expressed enzyme Activation-induced cytidine Deaminase (AID). Gene expression analyses of publically-available data (n = 234 GEO, n = 384 TCGA) confirmed heightened humoral responses (CD20, CD22, AID) in melanoma. Analyses of 51 melanoma-associated and 29 normal skin-derived IgG sequence repertoires revealed lower IgG1/IgG_total representation compared with antibodies from circulating B cells. Consistent with AID, comparable somatic hypermutation frequencies and class-switching indicated affinity-matured antibodies in normal and malignant skin. A melanoma-associated antibody subset featured shorter complementarity-determining (CDR3) regions relative to those from circulating B cells. Clonal amplification in melanoma-associated antibodies and homology modeling indicated differential potential antigen recognition profiles between normal skin and melanoma sequences, suggesting distinct antibody repertoires. Evidence for IgG-expressing B cells, class switching and antibody maturation in normal and malignant skin and clonally-expanded antibodies in melanoma, support the involvement of mature B cells in cutaneous immunity.

Vincristine-induced bystander effect in human lymphocytes

Bystander effect is a known radiobiological effect, widely described using ionizing radiations and which, more recently, has also been related to chemical mutagens. In this study, we aimed to assess whether or not a bystander response can be induced in cultured human peripheral lymphocytes by vincristine, a chemotherapeutic mutagen acting as spindle poison, and by mitomycin-C, an alkylating agent already known to induce this response in human lymphoblastoid cells. Designing a modified ad hoc protocol for the cytokinesis blocked micronucleus (MN) assay, we detected the presence of a dose-dependent bystander response in untreated cultures receiving the conditioned medium (CM) from mitomycin-C (MMC) or vincristine (VCR) treated cultures. In the case of MMC, MN frequencies, expressed as micronucleated binucleates, were: 13.5±1.41 at 6μM, 22±2.12 at 12μM or 28.25±5.13 at 15μM vs. a control value of 4.75±1.59. MN levels for VCR, expressed as micronucleated mononucleates were: 2.75±0.88 at 0.0μM, 27.25±2.30 at 0.4μM, 46.25±1.94 at 0.8μM, 98.25±7.25 at 1.6μM. To verify that no mutagen residual was transferred to recipient cultures together with the CM, we evaluated MN levels in cultures receiving the medium immediately after three washings following the chemical treatment (unconditioned medium). We further confirmed these results using a cell-mixing approach where untreated lymphocytes were co-cultured with donor cells treated with an effect-inducing dose of MMC or VCR. A distinct production pattern of both reactive oxygen species and soluble mediator proteins by treated cells may account for the differences observed in the manifestation of the bystander effect induced by VCR. In fact, we observed an increased level of ROS, IL-32 and TGF-β in the CM from VCR treated cultures, not present in MMC treated cultures.

Knowledge sharing in knowledge-intensive manufacturing firms. An empirical study of its enablers

Purpose

– This paper aims to investigate, following previous studies on knowledge-sharing (KS) processes that consist of knowledge donating (KD) and knowledge collecting (KC), the relationship between KS processes and KS enablers to understand the effect of organizational, individual and technological factors.

Design/methodology/approach

– The study is based on a Web survey. Data were collected from a sample of 759 knowledge workers selected from 23 knowledge-intensive manufacturing companies exposed to international markets and located in Tuscany (Italy). The analysis is based on multivariate regression models considering KD and KC as dependent variables.

Findings

– The results show that individual, organizational and technological factors matter to KS. Specifically, the paper reports that individual-level enablers and supportive leadership have a positive effect on both sub-processes of knowledge sharing. Further, the organic management system has a strong and positive impact on KD, while the efficacy of information and communication technology solutions is positively related to KC.

Research limitations/implications

– Although based on a geographically bounded perimeter, the analysis allows some generalizations. In fact, the paper proposes a set of enablers that empirically link micro- and macro-organizational mechanisms to KS.

Practical implications

– The evidence described can help improve the organizational management of KS and, consequently, support managers dealing with organizational design aimed at successful KS.

Originality/value

– The paper presents original results by combining individual, organizational and technological variables in the explanation of KS. It could be a basis for further studies.

The -308 TNFα and the -174 IL-6 promoter polymorphisms associate with effective anti-TNFα treatment in seronegative spondyloarthritis

The genetic predisposition to a long-term efficacy of anti-tumor necrosis factor (TNF)α treatment in seronegative spondyloarthritis (SpA) was investigated by analysing the possible correlation between several single nucleotide gene polymorphisms and the retention rate of anti-TNFα therapies. We compared patients needing to switch the first anti-TNFα (Sw, No. 64) within at least 12 months of follow-up with patients not needing to switch (NSw, No. 123), observing at least 6 months of treatment to establish anti-TNFα failure, leading to treatment change. Response to treatment was evaluated by standardised criteria (BASDAI for axial involvement, DAS28-EULAR for peripheral involvement). The TNFα -308 A allele and the interleukin (IL)-6 -174GG homozygosis resulted as independent biomarkers predicting survival of the first anti-TNFα therapy in SpA patients (P=0.007, odds ratio (OR): 4.4, 95% confidence interval (CI)=1.5-13.1 and P=0.035, OR: 2.1, 95% CI=1.1-4.4). Also, the male gender (P=0.001, OR: 3.4, 95% CI=1.6-7.1) associated with the NSw phenotype, whereas no association was found either with the specific diagnosis or the predominant joint involvement.

Exploring different cultural configurations: how do they affect subsidiaries’ knowledge sharing behaviors?

Purpose

– The purpose of this paper is to explore the impact of different cultural typologies (i.e. innovative, competitive, bureaucratic and community) on employees’ knowledge-sharing processes within multinational corporations (MNCs) by taking a subsidiary perspective. It particularly applies the competing values framework to the study of individuals’ orientations toward sharing knowledge with others while also investigating the influence of top management support on such orientations.

Design/methodology/approach

– To test the proposed hypotheses, in this paper, survey data of 389 employees from six Italian subsidiaries are empirically analyzed by running hierarchical regressions on the two dimensions of knowledge-sharing processes, i.e. knowledge donating and knowledge collecting.

Findings

– The results show that the four types of organizational culture differently affect the knowledge-sharing sub-processes and confirm the importance of a strong top management support to facilitate interpersonal relationships.

Research limitations/implications

– Despite the cross-sectional nature of the data and the limitations arising from the subsidiaries’ position in the country, the findings suggest managers to pay great attention to the positive side of bureaucracy by emphasizing the need for order and efficiency while, at the same time, providing employees with a constant and encouraging support toward knowledge-sharing activities.

Originality/value

– The paper adds empirical evidence to the limited existing research on knowledge-sharing sub-processes of knowledge donating and collecting, extends the understanding of how different organizational cultures affect such processes, and contributes to the literature on MNCs’ knowledge-based activities by adopting a subsidiary perspective.

Diabetes outcomes within integrated healthcare management programs

AIM

The aim of this observational study was to assess mortality of patients with type 2 diabetes by type of healthcare delivery system, i.e. through specialist centers or generalist doctors, or integrated care.

METHODS

The study was conducted at the "Vicentino Ovest" Local Health District in the Veneto Region (north-eastern Italy) from January 1, 2008 to December 31, 2010. Patients with diabetes (≥ 20 years old) were identified using different public health databases. They were grouped as: patients followed up by specialists at diabetes clinics (DS); patients seen only by their own general practitioner (GP); and patients receiving integrated care (DS-GP). Cox's regression analysis was used to estimate adjusted hazard ratios for available potential predictors of death by level of care.

RESULTS

The crude mortality rate was highest in the GP group (26.1 per 1000 person-years), the difference being minimal when compared with the DS group (21.7 per 1000 person-years) and more marked when compared with the DS-GP group (8.8 per 1000 person-years). Patients followed up by their GPs had a 2.7 adjusted RR for mortality by comparison with the DS-GP group.

CONCLUSIONS

The findings of the present study could demonstrate that it is safe and cost-effective, after a first specialist assessment at a diabetes service, for low-risk diabetic patients to be managed by family physicians as part of a coordinated care approach, based on the specialist's clinical recommendations; GPs can subsequently refer patients to a specialist whenever warranted by their clinical condition.

Growth hormone is secreted by normal breast epithelium upon progesterone stimulation and increases proliferation of stem/progenitor cells

Using in vitro and in vivo experimental systems and in situ analysis, we show that growth hormone (GH) is secreted locally by normal human mammary epithelial cells upon progesterone stimulation. GH increases proliferation of a subset of cells that express growth hormone receptor (GHR) and have functional properties of stem and early progenitor cells. In 72% of ductal carcinoma in situ lesions, an expansion of the cell population that expresses GHR was observed, suggesting that GH signaling may contribute to breast cancer development.

Aldehyde dehydrogenase and estrogen receptor define a hierarchy of cellular differentiation in the normal human mammary epithelium

INTRODUCTION

Although estrogen and progesterone play a key role in normal mammary development and in breast cancer, the potential for proliferation and lineage differentiation as well as origin of cells that express the estrogen receptor (ER) in normal breast epithelium are not known. Some evidence suggests that normal human mammary stem/progenitor cells are ER-, but the identity of these cells and the cellular hierarchy of breast epithelium are still subjects of controversy. It is likely that elucidation of these aspects will bring insight into the cellular origin of breast cancer subtypes.

METHODS

We used fluorescence-activated cell sorting of primary human mammary epithelial cells along with in vitro and in vivo functional assays to examine the hierarchic relation between cells with aldehyde dehydrogenase enzymatic activity (ALDH+ cells) and ER+ cells in the normal human breast epithelium. We assessed the proliferation and lineage differentiation potential of these cells in vitro and in vivo. A gene reporter assay was used to separate live ER+ and ER- mammary epithelial cells. With shRNA-mediated knockdown, we investigated the role of ALDH isoforms in the functionality of mammary epithelial progenitor cells.

RESULTS

We describe a cellular hierarchy in the normal human mammary gland in which ER-/ALDH+ cells with functional properties of stem/progenitor cells generate ER+ progenitor cells, which in turn give rise to cells of luminal lineage. We show that the ALDH1A1 isoform, through its function in the retinoic acid metabolism, affects the proliferation and/or early differentiation of stem/progenitor cells and is important for branching morphogenesis.

CONCLUSIONS

This study presents direct evidence that ER+ cells are generated by ER-/ALDH+ stem/progenitor cells. We also show that ER+ cells are able to generate cell progeny of luminal lineage in vitro and in vivo. Loss of ALDH1A1 function impairs this process, as well as branching morphogenesis and clonogenicity in suspension culture. This latter effect is reversed by treatment with retinoic acid.

Abstract LB-189: A role of Notch2 in quiescence of mammary stem/progenitor cells

Notch signaling plays an important role in normal tissue development through its role in cell-fate determination, survival and proliferation. There are four mammalian homologues, Notch1-4. It has been suggested that in the normal human breast, Notch signaling has a role in self-renewal of mammary stem cells and/or expansion of luminal progenitor cells, however the roles of individual Notch receptors are not clear. Activation of the Notch pathway has been associated with several human cancers, including breast cancer. Transgenic animals overexpressing Notch1, 3, or 4 in the mammary gland develop tumors. Notch 2 was part of gene expression signature for cancer stem cells from breast cancer cell lines, but its role in breast development and breast cancer is poorly understood. In order to investigate the role of Notch2 in functional assays we performed shRNA knockdown in primary mammary epithelial cells and assessed the effect on mammosphere formation. We found an increase in primary, secondary and tertiary sphere formation. Similar results were seen after silencing Notch2 in breast cancer cell lines, in standard cultivation systems. We investigated the expression of Notch2 in the normal mammary stem/progenitor cell population by immunohistochemical staining of normal breast sections. We detected an overlap between high levels of Notch2 expression and the stem/progenitor cell marker ALDH1A1. Furthermore, we detected a strong correlation between ALDH1A1 positive cells and nuclear localization of Notch downstream target Hes1, indicating that Notch signaling is active in these cells. As Hes1 has been implicated in stem cell quiescence, we performed double stainings for Hes1, ALDH1A1 and markers associated with cell proliferation (MCM2, Ki67) and cell quiescence (p21, p27). We found that ALDH1A1 positive cells were predominantly resting or quiescent. We also detected co-expression of Hes1 and the cell cycle protein p27, which controls cell cycle arrest in G1. Similar results were seen in a breast tumor xenografted in immunodeficient mice where tumor cells with high Notch2 expression were negative for the proliferation marker MCM2 and positive for p27. Taken together, our data indicate that Notch2 has a role in keeping stem/progenitor cells in a quiescent state in the normal breast epithelium and possibly in a subset of breast cancers. This is in contrast to the other Notch receptors, which seem to enhance cell proliferation. These results imply that response of breast cancers to treatment with Notch inhibitors (currently in clinical trials) may be determined by the relative expression and activity of the four Notch receptors. Targeting individual Notch receptors may represent a more tailored and more efficacious intervention.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-189. doi:1538-7445.AM2012-LB-189

Abstract LB-190: Growth hormone signaling in mammary stem and progenitor cells

The role of growth hormone (GH) in development of the normal mammary gland has been convincingly demonstrated in studies that show dramatically impaired mammary development in spontaneous dwarf rats and growth hormone receptor knock-out (GHR-KO) mice. There is also evidence that GH signaling may have a role in breast cancer. Animals treated with GH develop hyperproliferative lesions in the mammary gland and have increased incidence of spontaneous mammary tumors. Conversely, animals deficient in GH signaling are resistant to carcinogen-induced cancers, including mammary carcinoma. In humans, there is an increased incidence of cancer in patients with acromegaly (syndrome caused by excess GH production by pituitary gland) and a decreased incidence in patients with Laron syndrome (GH deficiency). In this study, we show that GH may increase the risk of breast cancer by stimulating stem and progenitor cells to enter the cell cycle. Using immunohistochemistry and immunostaining coupled with flow cytometry analysis, we found that GHR is expressed in stem and progenitor cells in the normal breast epithelium. We have previously shown that cells with ALDH activity from the human mammary epithelium have functional properties of stem/progenitor cells. Two thirds of these ALDH positive cells express GHR. GHR positive mammary epithelial cells are capable to initiate mammosphere formation in suspension culture and can generate both luminal and myoepithelial cell lineages in vitro. GH treatment increased mammosphere formation in a dose dependent manner. Although the total number of progeny was increased in these conditions, cell dynamics analysis using PKH26 dye dilution showed that the ratios between stem cells, early and late progenitor cells were not changed. GH treatment reduced the number of cells in quiescent state (G0) and decreased p21 protein levels, a cell-cycle regulator previously associated with stem cells quiescence. Taken together, these results indicated that GH treatment did not change symmetry of self-renewal cell divisions but increased the number of cycling mammary stem/progenitor cells. We found that GH is present in normal human mammary epithelial cells both in vitro and in vivo. In vitro, GH is secreted by mammary epithelial cells upon progesterone stimulation. We propose a model in which GH, estrogen and progesterone establish a paracrine signaling loop that stimulates GHR positive/steroid receptor negative stem and progenitor cells to enter the cell cycle. We propose that increased levels or prolonged exposure steroid hormones and/or GH would lead eventually to an expanded undifferentiated population at higher risk for transformation through oncogenic hits. Consistent with this concept, analysis of 180 cases of clinical precursor lesions (DCIS) showed an expanded GHR+ cell population in 92% of cases, with expression in 50-100% of the cell population in more than half of cases.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-190. doi:1538-7445.AM2012-LB-190

Study on the possible role of the -174G>C IL-6 promoter polymorphism in predicting response to rituximab in rheumatoid arthritis

OBJECTIVE

Identification of genetic biomarkers of response to biologics in rheumatoid arthritis (RA) is a relevant issue. The -174G>C interleukin-6 (IL-6) promoter polymorphism was investigated in RA patients treated with rituximab (RTX), being IL-6 a key cytokine for B cell survival and proliferation, thus possibly implicated in rituximab efficacy.

METHODS

The study was conducted in a real-life retrospective cohort of 142 unselected RA patients (120F/22M) treated with RTX and referred to 7 rheumatologic centres in the north of Italy. One hundred and thirteen (79.6%) patients were rheumatoid factor (RF)-positive and 112 (78.9%) were anti-CCP antibodies positive. The response to therapy was evaluated at the end of the sixth month after the first RTX infusion, by using both the EULAR criteria (DAS28) and the ACR criteria. The IL-6 -174G>C promoter polymorphism was analyzed by RFLP following previously reported methods.

RESULTS

Lack of response to RTX at month +6 by EULAR criteria was more prevalent in RA patients with the IL-6 -174 CC genotypes (9/21, 42.8%), than in the GC/GG patients (23/121, 19.0%) (OR 3.196, 95% CI=1.204-8.485; p=0.0234). Similar results were found when evaluating the response by ACR criteria. No differences were found in RA duration, baseline DAS28, baseline HAQ, RF status, anti-CCP status according to the different IL-6 -174 genotypes.

CONCLUSION

IL-6 promoter genotyping may be useful to better plan treatment with RTX in RA. Larger replication studies are in course to confirm these preliminary results.

[Rheumatoid factor positivity rather than anti-CCP positivity, a lower disability and a lower number of anti-TNFalpha agents failed are associated with response to rituximab in rheumatoid arthritis]

OBJECTIVE

Predictors of response to biologics in rheumatoid arthritis (RA) is an important issue in the current era. Rituximab (RTX) has been demonstrated effective and safe in active RA, resistant to traditional or biologic DMARDs.

METHODS

Fifty-seven patients with active longstanding RA were treated with RTX after traditional DMARD or anti-TNF alpha therapy failure.

RESULTS

Number of anti-TNF treatment previously failed (p=0.005), HAQ (p=0.013), rheumatoid factor (RF) (p=0.0002) and anti-CCP (p=0.006) were associated with an ACR response > or =50 at the end of 6th month by univariate analysis. Multivariate analysis confirmed that the number of anti-TNF previously failed, baseline HAQ and RF, but not anti-CCP were associated with an ACR response > or =50. EULAR moderate/good response was associated with ESR value (p=0.036), HAQ (p=0.032), and RF (p=0.01) by univariate analysis, while only RF positivity was associated with EULAR moderate/good response by multivariate analysis.

CONCLUSIONS

RF positivity rather than anti-CCP positivity is a predictor of response to RTX, suggesting that RF-positive patients with low disability may obtain a clinical response when treated to RTX after the first anti-TNF agent failure or after traditional DMARD therapies. Larger studies are required to confirm these results.