Switchable CAR T cell strategy against osteosarcoma

Immunotherapy with chimeric antigen receptor T (CAR T) cells has changed the treatment of hematological malignances, but they are still a challenge for solid tumors, including pediatric sarcomas. Here, we report a switchable CAR T cell strategy based on anti-FITC CAR T cells and a switch molecule conjugated with FITC for targeting osteosarcoma (OS) tumors. As a potential target, we analyzed the expression of B7-H3, an immune checkpoint inhibitor, in OS cell lines. In addition, we evaluate the capacity of an anti-B7-H3 monoclonal antibody conjugated with FITC (anti-B7-H3-FITC mAb) to control the antitumor activity of anti-FITC CAR T cells. The effector functions of anti-FITC CAR T cells against OS, measured in vitro by tumor cell killing activity and cytokine production, are dependent on the presence of the anti-B7-H3-FITC mAb switch. Moreover, OS cells stimulate anti-FITC CAR T cells migration. In vivo, anti-B7-H3 mAb penetrates in the tumor and binds 143B OS tumor cells. Furthermore, anti-FITC CAR T cells reach tumor region and exert antitumor effect in an OS NSG mouse model only in the presence of the switch molecule. We demonstrate that anti-B7-H3-FITC mAb redirects the cytotoxic activity of anti-FITC CAR T cells against OS tumors suggesting that switchable CAR T cell platforms might be a plausible strategy against OS.

Public Health-Led Insights on Electric Micro-mobility Adoption and Use: a Scoping Review

The advent of electric micro-mobility (EMM) has transformed the urban mobility landscape, with projections indicating a 5-10% increase in its modal share in European cities by 2030. In this scoping review, we aimed to comprehensively examine the key determinants of EMM adoption and usage from a public health perspective. Sixty-seven articles were included in the analysis, primarily covering e-bikes and e-scooters. The determinants were categorised into two broad categories: (1) contextual determinants that encompass enabling and hindering factors related to legal frameworks, transportation systems and infrastructure, and technology, and (2) individual-level determinants that pertain to intrinsic motivations and deterrents of individuals. Our findings reveal that EMM vehicles are widely perceived as a cost-effective, flexible, ad hoc, and fast mode of transportation within urban areas, augmenting accessibility and connectivity. Additionally, the lightweight, foldable, and transportable nature of these vehicles is highly appreciated by users. However, several barriers have also been identified, including inadequate infrastructure and end-of-trip facilities, limited capability to traverse diverse terrains and trip scenarios, acquisition and maintenance costs, limited carrying capacities, technical failures, and accident risks. Our results suggest that the interplay of contextual enablers and barriers and personal motivations and deterrents drive the emergence, adoption, and usage of EMM. Hence, a comprehensive understanding of both contextual and individual-level determinants is crucial for ensuring a sustainable and healthy uptake of EMM.

Personal strategies to mitigate the effects of air pollution exposure during sport and exercise: a narrative review and position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology

Air pollution is among the leading environmental threats to health around the world today, particularly in the context of sports and exercise. With the effects of air pollution, pollution episodes (eg, wildfire conflagrations) and climate change becoming increasingly apparent to the general population, so have their impacts on sport and exercise. As such, there has been growing interest in the sporting community (ie, athletes, coaches, and sports science and medicine team members) in practical personal-level actions to reduce the exposure to and risk of air pollution. Limited evidence suggests the following strategies may be employed: minimising all exposures by time and distance, monitoring air pollution conditions for locations of interest, limiting outdoor exercise, using acclimation protocols, wearing N95 face masks and using antioxidant supplementation. The overarching purpose of this position statement by the Canadian Academy of Sport and Exercise Medicine and the Canadian Society for Exercise Physiology is to detail the current state of evidence and provide recommendations on implementing these personal strategies in preventing and mitigating the adverse health and performance effects of air pollution exposure during exercise while recognising the limited evidence base.

Impacts of changes in environmental exposures and health behaviours due to the COVID-19 pandemic on cardiovascular and mental health: A comparison of Barcelona, Vienna, and Stockholm

Responses to COVID-19 altered environmental exposures and health behaviours associated with non-communicable diseases. We aimed to (1) quantify changes in nitrogen dioxide (NO₂), noise, physical activity, and greenspace visits associated with COVID-19 policies in the spring of 2020 in Barcelona (Spain), Vienna (Austria), and Stockholm (Sweden), and (2) estimated the number of additional and prevented diagnoses of myocardial infarction (MI), stroke, depression, and anxiety based on these changes. We calculated differences in NO₂, noise, physical activity, and greenspace visits between pre-pandemic (baseline) and pandemic (counterfactual) levels. With two counterfactual scenarios, we distinguished between Acute Period (March 15th - April 26th, 2020) and Deconfinement Period (May 2nd - June 30th^, 2020) assuming counterfactual scenarios were extended for 12 months. Relative risks for each exposure difference were estimated with exposure-risk functions. In the Acute Period, reductions in NO₂ (range of change from -16.9 μg/m³ to -1.1 μg/m³), noise (from -5 dB(A) to -2 dB(A)), physical activity (from -659 MET*min/wk to -183 MET*min/wk) and greenspace visits (from -20.2 h/m to 1.1 h/m) were largest in Barcelona and smallest in Stockholm. In the Deconfinement Period, NO₂ (from -13.9 μg/m³ to -3.1 μg/m³), noise (from -3 dB(A) to -1 dB(A)), and physical activity levels (from -524 MET*min/wk to -83 MET*min/wk) remained below pre-pandemic levels in all cities. Greatest impacts were caused by physical activity reductions. If physical activity levels in Barcelona remained at Acute Period levels, increases in annual diagnoses for MI (mean: 572 (95% CI: 224, 943)), stroke (585 (6, 1156)), depression (7903 (5202, 10,936)), and anxiety (16,677 (926, 27,002)) would be anticipated. To decrease cardiovascular and mental health impacts, reductions in NO₂ and noise from the first COVID-19 surge should be sustained, but without reducing physical activity. Focusing on cities' connectivity that promotes active transportation and reduces motor vehicle use assists in achieving this goal.

Minimal impact of ZAP on lentiviral vector production and transduction efficiency

The antiviral protein ZAP binds CpG dinucleotides in viral RNA to inhibit replication. This has likely led to the CpG suppression observed in many RNA viruses, including retroviruses. Sequences added to retroviral vector genomes, such as internal promoters, transgenes, or regulatory elements, substantially increase CpG abundance. Because these CpGs could allow retroviral vector RNA to be targeted by ZAP, we analyzed whether it restricts vector production, transduction efficiency, and transgene expression. Surprisingly, even though CpG-high HIV-1 was efficiently inhibited by ZAP in HEK293T cells, depleting ZAP did not substantially increase lentiviral vector titer using several packaging and genome plasmids. ZAP overexpression also did not inhibit lentiviral vector titer. In addition, decreasing CpG abundance in a lentiviral vector genome did not increase its titer, and a gammaretroviral vector derived from murine leukemia virus was not substantially restricted by ZAP. Overall, we show that the increased CpG abundance in retroviral vectors relative to the wild-type retroviruses they are derived from does not intrinsically sensitize them to ZAP. Further understanding of how ZAP specifically targets transcripts to inhibit their expression may allow the development of CpG sequence contexts that efficiently recruit or evade this antiviral system.

Housing and health: a collaborative project for evidence-based policy-making

Issue

The potential to improve health and equity through better housing is well established. However, housing policies (mainly focused on energy efficiency) have not fully integrated health.

Description

Within the Urban Environment and Health Project of the Diputació de Barcelona, their Housing and Public Health Offices and the Barcelona Institute for Global Health undertook the first phase (May-December 2020) of a collaborative project on housing and health. Focused on the physical dwelling, a map of health risk factors (linked to thermal comfort, environmental and spatial quality), a literature review of each factor, and a list of local health-promoting housing programs were elaborated. Issues addressed included: (a) most relevant home factors affecting health; (b) evidence of poor housing conditions impacting physical, mental, and social health of residents; (c) housing improvements with documented positive health benefits. The second phase (March-December 2021) uses the same methods to address two new housing dimensions: residential environment and community.

Results

Recent research on housing and health explores the potential accumulative/synergistic effects of combined exposures, as additional poor housing parameters (e.g. low indoor air quality, lack of natural light, pest problems, material damage) correlate with poorer health status and higher use of medical resources. Through this collaborative project, increased awareness among local officers has led to preliminary context-specific criteria and parameters to promote healthy homes beyond compliance with current building codes, especially aimed at increasing maintenance and renovation standards in older neighborhoods of Barcelona.

Lessons

Collaboration between stakeholders allows for rich and innovative perspectives and encourages multisectoral actions. Context-specific health costs/benefits analyses are needed to facilitate development and implementation of housing policies with health at its core.

Key messages

Housing policies should have a holistic approach of health risks, redounding in housing policies improvement. Collaborative projects between academic institutions and local governments encourage pivotal evidence-based housing policy-making.

OP0004 AUTOIMMUNE AND INFLAMMATORY MANIFESTATIONS IN COMMON VARIABLE IMMUNODEFICIENCY DISORDERS

Background:

Common variable immunodeficiency (CVID) disorders are the second most frequent immunodeficiency worldwide and autoimmune diseases (AD) are present in 20% of such patients, cytopenia being the most frequent manifestation [1]. Defects in central and peripheral tolerance, activation/proliferation of B cells, and hypogammaglobulinemia are key features of the disease, along with a reduction in CD4+T cells, abnormalities in Treg and defective secretion of regulatory cytokines, that could perpetuate autoimmune - autoinflammatory phenomena.

Objectives:

To describe immune and inflammatory disorders in our CVID cohort.

Methods:

Retrospective analysis of 33 patients who fulfill the European Society for Immunodeficiencies (ESID) Registry – Work criteria for CVID diagnosis [2] treated in the immunodeficiency unit of our tertiary university hospital. After getting an informed consent form, medical records were revised to obtain clinical, analytical and immunological data.

Results:

Of the 33 CVID patients analysed, 11 had some autoimmune/inflammatory manifestation. Seven patients presented autoimmune thrombocytopenia (AIT), and one of them also had non-severe neutropenia. Two patients also had seronegative spondyloarthropathy, one patient had cutaneous psoriasis, and two patients had alopecia. There were no cases of type 1 diabetes, vitiligo or thyroid disorders. Interestingly, four patients had lung involvement, two of them with granulomatous-lymphocytic interstitial lung disease (GLILD), one with organising pneumonia and one with usual interstitial pneumonia. Five of the eleven patients required immunosuppressive treatment, mostly with steroids. One case of AIT required concomitant treatment with azathioprine and the patient with psoriasis was treated with methotrexate. In six patients, autoimmune disorder was the first manifestation.

Conclusion:

33% of the CVID patients had autoimmune or inflammatory manifestations in our cohort; six patients had one immune/inflammatory phenomena, four had two different disorders and one patient presented with three different ones. The most frequent manifestation was AIT, as seen in previous reports. In six cases, the autoimmune-inflammatory manifestation was the first symptom attributable to CVID. In conclusion, AD are common in CVID patients, so clinicians must be aware of possible immunodeficiencies in this type of patients.

References:

[1]Amaya-Uribe L, Rojas M, Azizi G, Anaya JM, Gershwin ME. Primary immunodeficiency and autoimmunity: A comprehensive review. J Autoimmun. 2019 May;99:52-72.

[2]ESID Registry – Working Definitions for Clinical Diagnosis of PID, January 22, 2019.

Disclosure of Interests:

None declared

Prevalence, risk factors and genetic characterisation of extended-spectrum beta-lactamase and carbapenemase-producing Enterobacteriaceae (ESBL-E and CPE): a community-based cross-sectional study, the Netherlands, 2014 to 2016

Background

The epidemiology of carriage of extended-spectrum beta-lactamase-producing (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in the general population is unknown.

Aim

In this observational study, the prevalence and risk factors for intestinal ESBL-E and CPE carriage in the Dutch general population were determined. ESBL-E were characterised.

Methods

From 2014 to 2016, ca 2,000 residents were invited monthly to complete a questionnaire and provide a faecal sample, which was tested for ESBL-E. The first 1,758 samples were also tested for CPE. Risk factors for ESBL-E carriage were identified by multivariable logistic regression analysis. ESBL-E isolates underwent whole genome sequencing.

Results

Of 47,957 individuals invited, 4,177 (8.7%) completed the questionnaire and provided a faecal sample. ESBL-E were detected in 186 (4.5%) individuals, resulting in an adjusted prevalence of 5.0% (95% confidence interval (CI):3.4–6.6%). Risk factors were: born outside the Netherlands (odds ratio (OR): 1.99; 95% CI: 1.16−4.54), eating in restaurants > 20 times/year (OR: 1.70; 95% CI: 1.04−2.76), antibiotic use < 6 months ago (OR: 2.05; 95% CI: 1.05−4.03), swimming in sea/ocean < 12 months ago (OR: 1.63; 95% CI: 1.11−2.39), travelling to Africa (OR: 3.03; 95% CI: 1.23−7.46) or Asia (OR: 2.00; 95% CI: 1.02−3.90) < 12 months ago, and not changing kitchen towels daily (OR: 2.19; 95% CI: 1.24−3.87). The last had the largest population attributable risk (PAR) (47.5%). Eighty-four of 189 (44.4%) ESBL-E isolates carried bla_CTX-M-15. Escherichia coli isolates belonged to 70 different sequence types (ST)s, of which ST131 (42/178 isolates; 23.6%) was most prevalent. Associations were observed between IncFIA plasmids and ST131 and bla_CTX-M-27, and between IncI1 and ST88 and bla_CTX-M-1. No CPE were detected.

Conclusions

The prevalence of ESBL-E carriage in the Netherlands’ community-dwelling population is 5.0%. Identified risk factors were mostly travelling (particularly to Asia and Africa) and kitchen hygiene. CPE were not detected.

Characterization of human fibroblastic reticular cells as potential immunotherapeutic tools

Fibroblastic reticular cells (FRCs) are essential players during adaptive immune responses not only as a structural support for the encounter of antigen-presenting cells and naive T lymphocytes but also as a source of modulatory signals. However, little is known about this cell population in humans. To address the phenotypical and functional analysis of human FRCs here we established splenic (SP) and mesenteric lymph node (LN) CD45^-CD31^-CD90⁺podoplanin⁺ myofibroblastic cell cultures. They shared the phenotypical characteristics distinctive of FRCs, including the expression of immunomodulatory factors and peripheral tissue antigens. Nevertheless, human FRCs also showed particular features, some differing from mouse FRCs, like the lack of nitric oxide synthase (NOS2) expression after interferon (IFN)γstimulation. Interestingly, SP-FRCs expressed higher levels of interleukin (IL)-6, BMP4, CCL2, CXCL12 and Notch molecules, and strongly adapted their functional profile to lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C) and IFNγ stimulation. In contrast, we found higher expression of transforming growth factor (TGF)β and Activin A in LN-FRCs that barely responded via Toll-Like Receptor (TLR)3 and constitutively expressed retinaldehyde dehydrogenase 1 enzyme, absent in SP-FRCs. This study reveals human FRCs can be valuable models to increase our knowledge about the physiology of human secondary lymphoid organs in health and disease and to explore the therapeutic options of FRCs.

Molecular Assessment of Microcirculation Injury in Formalin-Fixed Human Cardiac Allograft Biopsies With Antibody-Mediated Rejection

Precise diagnosis of antibody-mediated rejection (AMR) in cardiac allograft endomyocardial biopsies (EMBs) remains challenging. This study assessed molecular diagnostics in human EMBs with AMR. A set of 34 endothelial, natural killer cell and inflammatory genes was quantified in 106 formalin-fixed, paraffin-embedded EMBs classified according to 2013 International Society for Heart and Lung Transplantation (ISHLT) criteria. The gene set expression was compared between ISHLT diagnoses and correlated with donor-specific antibody (DSA), endothelial injury by electron microscopy (EM) and prognosis. Findings were validated in an independent set of 57 EMBs. In the training set (n = 106), AMR cases (n = 70) showed higher gene set expression than acute cellular rejection (ACR; n = 21, p < 0.001) and controls (n = 15, p < 0.0001). Anti-HLA DSA positivity was associated with higher gene set expression (p = 0.01). Endothelial injury by electron microscopy strongly correlated with gene set expression, specifically in AMR cases (r = 0.62, p = 0.002). Receiver operating characteristic curve analysis for diagnosing AMR showed greater accuracy with gene set expression (area under the curve [AUC] = 79.88) than with DSA (AUC = 70.47) and C4d (AUC = 70.71). In AMR patients (n = 17) with sequential biopsies, increasing gene set expression was associated with inferior prognosis (p = 0.034). These findings were confirmed in the validation set. In conclusion, biopsy-based molecular assessment of antibody-mediated microcirculation injury has the potential to improve diagnosis of AMR in human cardiac transplants.

A discrete population of IFN λ-expressing BDCA3hi dendritic cells is present in human thymus

Human thymus contains two major subpopulations of dendritic cells (DCs), conventional DCs (cDCs) and plasmacytoid DCs (pDCs), which are mainly involved in central tolerance and also in protecting the thymus against infections. In blood and peripheral organs cDCs include the subpopulation of BDCA3(hi) DCs, considered as equivalents to mouse CD8α(+) DCs. In this study we describe in human thymus the presence of a discrete population of BDCA3(hi) DCs that, like their peripheral counterparts, express CD13, low-intermediate levels of CD11c, CLEC9A, high levels of XCR1, IRF8 and TLR3, and mostly lack the expression of CD11b, CD14 and TLR7. Thymic BDCA3(hi) DCs display immature features with a low expression of costimulatory molecules and HLA-DR, and a low allostimulatory capacity. Also, BDCA3(hi) DCs exhibit a strong response to TLR3 stimulation, producing high levels of interferon (IFN)-λ1 and CXCL10, which indicates that, similarly to thymic pDCs, BDCA3(hi) DCs can have an important role in thymus protection against viral infections.

Blockade of bone morphogenetic protein signaling potentiates the pro-inflammatory phenotype induced by interleukin-17 and tumor necrosis factor-α combination in rheumatoid synoviocytes

Introduction

Bone morphogenetic proteins (BMPs) are multifunctional secreted growth factors regulating a broad spectrum of functions in numerous systems. An increased expression and production of specific BMPs have been described in the rheumatoid arthritis (RA) synovium. The aim of this study was to analyze the involvement of the BMP signaling pathway in RA synoviocytes in response to interleukin-17 (IL-17) and tumor necrosis factor-alpha (TNF-α).

Methods

The expression of components of the BMP signaling pathway (BMP receptors, BMP ligands, BMP signal transducers, and BMP antagonists) was analyzed by quantitative polymerase chain reaction before and after treatment of RA synoviocytes with TNF-α or IL-17 or both. Regulation was studied in the presence of the specific BMP inhibitor DMH1 (dorsomorphin homologue 1) or an exogenous BMP ligand, BMP6. Expression and production of pro-inflammatory cytokines (IL-6 and granulocyte-macrophage colony-stimulating factor), chemokines (IL-8, CCL2, CCL5, and CXCL10), and matrix metalloproteinases (MMP-1, −2, −3, −9, and −13) were analyzed.

Results

RA synoviocytes express BMP receptors (mainly BMPRIA, ACTRIA, and BMPRII), signal transducers of the Smad family (Smad1 and 5 and co-Smad4), and different BMP antagonists. The modulation of the expression of the BMP target genes—Id (inhibitor of DNA-binding/differentiation) proteins and Runx (Runt-related transcription factor) transcription factors—after the addition of exogenous BMP shows that the BMP signaling pathway is active. RA synoviocytes also express BMP ligands (BMP2, BMP6, and BMP7) which are highly upregulated after activation with TNF-α and IL-17. Autocrine BMP signaling pathway can be blocked by treatment with the inhibitor DMH1, leading to an increase in the upregulated expression of pro-inflammatory cytokines, chemokines, and MMPs induced by the activation of RA synoviocytes with TNF-α and IL-17. Conversely, the additional stimulation of the BMP pathway with the exogenous addition of the BMP6 ligand decreases the expression of those pro-inflammatory and pro-destructive factors.

Conclusion

The results indicate that the canonical BMP pathway is functionally active in human RA synoviocytes and that the inhibition of autocrine BMP signaling exacerbates the pro-inflammatory phenotype induced in RA synoviocytes by the stimulation with IL-17 and TNF-α.

Optimal effector functions in human natural killer cells rely upon autocrine bone morphogenetic protein signaling

Natural killer (NK) cells are critical for innate tumor immunity due to their specialized ability to recognize and kill neoplastically transformed cells. However, NK cells require a specific set of cytokine-mediated signals to achieve optimal effector function. Th1-associated cytokines promote effector functions that are inhibited by the prototypic Th2 cytokine IL4 and the TGFβ superfamily members TGFβ1 and activin-A. Interestingly, the largest subgroup of the TGFβ superfamily are the bone morphogenetic proteins (BMP), but the effects of BMP signaling on NK cell effector functions have not been evaluated. Here, we demonstrate that blood-circulating NK cells express type I and II BMP receptors, BMP-2 and BMP-6 ligands, and phosphorylated isoforms of Smad-1/-5/-8, which mediate BMP family member signaling. In opposition to the inhibitory effects of TGFβ1 or activin-A, autocrine BMP signaling was supportive to NK cell function. Mechanistic investigations in cytokine and TLR-L-activated NK cells revealed that BMP signaling optimized IFNγ and global cytokine and chemokine production, phenotypic activation and proliferation, and autologous dendritic cell activation and target cytotoxicity. Collectively, our findings identify a novel auto-activatory pathway that is essential for optimal NK cell effector function, one that might be therapeutically manipulated to help eradicate tumors. Cancer Res; 74(18); 5019-31. ©2014 AACR.

Autocrine activation of canonical BMP signaling regulates PD-L1 and PD-L2 expression in human dendritic cells

Bone morphogenetic proteins (BMPs) are multifunctional growth factors regulating differentiation and proliferation in numerous systems including the immune system. Previously, we described that the BMP signaling pathway is functional in human monocyte-derived dendritic cells (MoDCs), which were found to express both the specific receptors and the Smad proteins required for signal transduction. In this study, we provide evidence that human MoDCs produce BMP-4 and that this production is increased over the maturation process as is BMP signal transduction. When DCs are matured in the presence of an inhibitor of the BMP pathway, the expression of the maturation markers PD-L1 and PD-L2 is reduced, while cytokine production is not affected. As a result, these mature DCs present an augmented ability to stimulate both T cells and NK cells. Eventually, the inhibition of BMP signaling during maturation causes a reduced expression of IRF-1, a transcription factor that positively regulates the expression of PD-L1 and PD-L2. The present study indicates that the BMP signaling pathway regulates PD-L1 and PD-L2 expression in human MoDCs during the maturation process, probably through the IRF-1 transcription factor, and also points out that the manipulation of BMP signaling might considerably improve the immunogenicity of MoDCs used in immunotherapy.

Association of the novel aminoglycoside resistance determinant RmtF with NDM carbapenemase in Enterobacteriaceae isolated in India and the UK

OBJECTIVES

16S rRNA methyltransferases are an emerging mechanism conferring high-level resistance to clinically relevant aminoglycosides and have been associated with important mechanisms such as NDM-1. We sought genes encoding these enzymes in isolates highly resistant (MIC >200 mg/L) to gentamicin and amikacin from an Indian hospital and we additionally screened for the novel RmtF enzyme in 132 UK isolates containing NDM.

METHODS

All highly aminoglycoside-resistant isolates were screened for armA and rmtA-E by PCR, with cloning experiments performed for isolates negative for these genes. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was used to determine the methylation target of the novel RmtF methyltransferase. RmtF-bearing strains were characterized further, including susceptibility testing, PFGE, electroporation, PCR-based replicon typing and multilocus sequence typing of rmtF-bearing plasmids.

RESULTS

High-level aminoglycoside resistance was detected in 140/1000 (14%) consecutive isolates of Enterobacteriaceae from India. ArmA, RmtB and RmtC were identified among 46%, 20% and 27% of these isolates, respectively. The novel rmtF gene was detected in 34 aminoglycoside-resistant isolates (overall prevalence 3.4%), most (59%) of which also possessed a bla(NDM) gene; rmtF was detected in 6 NDM producers from the UK. It was found on different plasmid backbones. Four and two isolates showed resistance to tigecycline and colistin, respectively.

CONCLUSIONS

RmtF was often found in association with NDM in members of the Enterobacteriaceae and on diverse plasmids. It is of clinical concern that the RmtF- and NDM-positive strains identified here show additional resistance to tigecycline and colistin, current drugs of last resort for the treatment of serious bacterial infections.

Molecular diagnosis of T cell-mediated rejection in human kidney transplant biopsies

Histologic diagnosis of T cell-mediated rejection is flawed by subjective assessments, nonspecific lesions and arbitrary rules. This study developed a molecular test for T cell-mediated rejection. We used microarray results from 403 kidney transplant biopsies to derive a classifier assigning T cell-mediated rejection scores to all biopsies, and compared these with histologic assessments. The score correlated with histologic lesions of T cell-mediated rejection (infiltrate, tubulitis). The accuracy of the classifier for the histology diagnoses was 89%. Very high and low molecular scores corresponded with unanimity among three pathologists on the presence or absence of T cell-mediated rejection, respectively. The molecular score had low sensitivity (50%) and positive predictive value (62%) for the histology diagnoses. However, histology showed similar disagreement between pathologists--only 45-56% sensitivity of one pathologist with diagnoses of T cell-mediated rejection by another. Discrepancies between molecular scores and histology were mostly when histology was ambiguous ("borderline") or unreliable, e.g. in cases with scarring or inflammation induced by tissue injury. Vasculitis (isolated v-lesion TCMR) was particularly discrepant, with most cases exhibiting low TCMR scores. We propose new rules to integrate molecular tests and histology into a precision diagnostic system that can reduce errors, ambiguity and interpathologist disagreement.

A new diagnostic algorithm for antibody-mediated microcirculation inflammation in kidney transplants

We studied the significance of microcirculation inflammation in kidney transplants, including 329 indication biopsies from 251 renal allograft recipients, who were mostly nonpresensitized (crossmatch negative). Glomerulitis (g) and peritubular capillaritis (ptc) were often associated with antibody-mediated rejection (65% and 75%, respectively), but were also found in other diseases in the absence of donor-specific antibody (DSA): T-cell-mediated rejection (ptc, g), glomerulonephritis (g) and acute tubular necrosis (ptc). To develop rules for reducing the nonspecificity of microcirculation inflammation and defining the best grading thresholds associated with DSA, we built and validated a decision tree to predict DSA. The decision tree revealed that g + ptc sum (addition of g-score plus ptc-score) was the best predictor of DSA, followed by time posttransplant, then C4d, which had a small role. Late biopsies with g + ptc > 0 showed higher frequency of DSA compared to early biopsies with g + ptc > 0 (79% vs. 27%). Microcirculation inflammation in early biopsies was often false positive (antibody-independent). The decision tree predicted DSA with higher sensitivity and accuracy than C4d staining. Microcirculation inflammation sum score predicted graft failure independently of time, C4d and transplant glomerulopathy. Thus any degree of microcirculation inflammation in late kidney transplant biopsies strongly indicates presence of DSA and predicts progression to graft failure.

Fitness cost and interference of Arm/Rmt aminoglycoside resistance with the RsmF housekeeping methyltransferases

Arm/Rmt methyltransferases have emerged recently in pathogenic bacteria as enzymes that confer high-level resistance to 4,6-disubstituted aminoglycosides through methylation of the G1405 residue in the 16S rRNA (like ArmA and RmtA to -E). In prokaryotes, nucleotide methylations are the most common type of rRNA modification, and they are introduced posttranscriptionally by a variety of site-specific housekeeping enzymes to optimize ribosomal function. Here we show that while the aminoglycoside resistance methyltransferase RmtC methylates G1405, it impedes methylation of the housekeeping methyltransferase RsmF at position C1407, a nucleotide that, like G1405, forms part of the aminoglycoside binding pocket of the 16S rRNA. To understand the origin and consequences of this phenomenon, we constructed a series of in-frame knockout and knock-in mutants of Escherichia coli, corresponding to the genotypes rsmF(+), ΔrsmF, rsmF(+) rmtC(+), and ΔrsmF rmtC(+). When analyzed for the antimicrobial resistance pattern, the ΔrsmF bacteria had a decreased susceptibility to aminoglycosides, including 4,6- and 4,5-deoxystreptamine aminoglycosides, showing that the housekeeping methylation at C1407 is involved in intrinsic aminoglycoside susceptibility in E. coli. Competition experiments between the isogenic E. coli strains showed that, contrary to expectation, acquisition of rmtC does not entail a fitness cost for the bacterium. Finally, matrix-assisted laser desorption ionization (MALDI) mass spectrometry allowed us to determine that RmtC methylates the G1405 residue not only in presence but also in the absence of aminoglycoside antibiotics. Thus, the coupling between housekeeping and acquired methyltransferases subverts the methylation architecture of the 16S rRNA but elicits Arm/Rmt methyltransferases to be selected and retained, posing an important threat to the usefulness of aminoglycosides worldwide.

The B-Lynch technique for the management of intraoperative uterine atony

This paper reports the experience of 150 B-Lynch suture applications for the management of uterine atony during caesarean section that did not respond to conventional therapeutical measures. Technique was considered effective if the need for hysterectomy was avoided. High-risk antenatal obstetrical conditions included: pre-eclampsia (12%), oligohydramnios (8%), polyhydramnios (4.7%). A total of 36% were primigravid, 66% had been in active labour, 4.7% received misoprostol and 26.7% used oxytocin for labour augmentation. Suture was successful in 95.3%, with only five cases requiring hysterectomy combined with uterine artery ligation and two uterine artery ligations alone to control bleeding and uterine atony ('floppiness'). Although 26.7% of cases required transfusions, no maternal deaths were reported, and overall women were discharged after a median 4-day hospital stay without further complications upon follow-up. The B-Lynch technique was an effective intraoperative measure to control uterine atony. Despite the encouraging results, long term assessment on a larger sample is needed in our clinical scenario.

Wnt5a skews dendritic cell differentiation to an unconventional phenotype with tolerogenic features

Dendritic cells (DCs) are critical regulators of immune responses that integrate signals from the innate and adaptive immune system and orchestrate T cell responses toward either immunity or tolerance. Growing evidence points to the Wnt signaling pathway as a pivotal piece in the immune balance and focuses on DCs as a direct target for their immunoregulatory role. Our results show that the increase in Wnt5a signaling during the differentiation of human DCs from monocytes alters their phenotype and compromises their subsequent capacity to mature in response to TLR-dependent stimuli. These Wnt5a-DCs produce scant amounts of IL-12p70 and TNF-α but increased levels of IL-10. Consequently, these Wnt5a-DCs have a reduced capacity to induce Th1 responses that promote IL-10 secretion by CD4 T cells. Changes in the transcriptional profile of Wnt5a-DCs correlate with their unconventional phenotype caused presumably by increased IL-6/IL-10 signaling during the process of DC differentiation. The effect of Wnt5a is not a consequence of β-catenin accumulation but is dependent on noncanonical Ca(2+)/calmodulin-dependent protein kinase II/NF-κB signaling. Our results therefore suggest that under high levels of Wnt5a, typical of the inflammatory state and sepsis, monocytes could differentiate into unconventional DCs with tolerogenic features.

Contribution of ROB-1 and PBP3 mutations to the resistance phenotype of a β-lactamase-positive amoxicillin/clavulanic acid-resistant Haemophilus influenzae carrying plasmid pB1000 in Italy

OBJECTIVES

plasmid pB1000 bearing bla(ROB-1) is responsible for high-level β-lactam resistance in Haemophilus influenzae as well as in Pasteurella multocida and Haemophilus parasuis isolates from Spain. Here, we explore the presence of ROB-1 in Italy and investigate the relative contribution of penicillin-binding protein 3 (PBP3) mutations and ROB-1 to the β-lactam resistance phenotype in H. influenzae.

METHODS

the collection of the Italian Reference Laboratory of H. influenzae was investigated for ROB-1-positive isolates between 2004 and 2009. H. influenzae Rd KW20 was used as recipient for pB1000 electroporation and for mutagenesis of the ftsI gene encoding PBP3.

RESULTS

the presence of plasmid pB1000 in a non-typeable H. influenzae isolated in Italy, BB1059, is reported in this work. This strain is not genetically related to the H. influenzae clinical isolates bearing pB1000 described in Spain. The sequence of ftsI from BB1059 revealed several mutations in the predicted amino acid sequence of PBP3. To determine the relative contribution of pB1000 and PBP3 mutations to the β-lactam resistance phenotype of BB1059, H. influenzae Rd KW20 was transformed with ftsI and/or pB1000 from BB1059. β-Lactam resistance profiles revealed the additive effect of pB1000 and PBP3 mutations conferring resistance to β-lactams, including amoxicillin/clavulanic acid and third-generation cephalosporins.

CONCLUSIONS

intra-European spread of plasmid pB1000 among H. influenzae has been shown. The coexistence of plasmid pB1000 and mutations in PBP3 produces an additive resistance phenotype in H. influenzae.

16S rRNA methyltransferase RmtC in Salmonella enterica serovar Virchow

We screened Salmonella and Escherichia coli isolates, collected 2004-2008 in the United Kingdom, for 16S rRNA methyltransferases. rmtC was identified in S. enterica serovar Virchow isolates from clinical samples and food. All isolates were clonally related and bore the rmtC gene on the bacterial chromosome. Surveillance for and research on these resistance determinants are essential.

[Management of distal ureter in laparoscopic nephroureterectomy]

INTRODUCTION

Nephroureterectomy is one of the procedures for which a laparoscopic approach is more clearly indicated. However, despite the long experience available, management of the distal ureter is still difficult.

MATERIALS AND METHODS

Thirty-two laparoscopic nephroureterectomies were performed from November 2004 to December 2008. The procedure used was endoscopic resection of distal ureter and earlier ligation of the ureter in the laparoscopic time in 13 patients, a laparoscopic bladder cuff in 13 patients, and an open bladder cuff in 3 patients.

RESULTS

Mean operating time was 221.53 min (125-315 min), and mean postoperative stay of 27 patients was 4.6 days. Conversion to open surgery and discontinuation of the procedure for local tumor progression were required in one patient each. Mean patient follow-up was 17.8 months. No local relapse or metastasis occurred in the ports.

CONCLUSION

The most common procedures continue to be endoscopic resection and the open bladder cuff depending on indication. Any laparoscopic approach to upper urothelial tumors must strictly comply with oncological principles. The reported procedure is in our experience the fastest, most simple, and most effective for this purpose. In our opinion, the therapeutic algorithm provided is adequate for management of the distal ureter in laparoscopic nephroureterectomy.

The CXCL12/CXCR4 pair in aged human thymus

CXCL12 is an important CXC chemokine involved in numerous biological processes. We had previously demonstrated the synergistic participation of CXCL12 and IL-7 in the control of both survival and proliferation of CD34(+) human thymic lymphoid progenitors. On this basis, we hypothesize a presumptive role for CXCL12 and its receptor, CXCR4, in the thymus involution. In this respect, in the current report we describe the expression of both molecules in the human thymus during aging. Our results demonstrate that, despite the profound alterations observed in the thymic epithelial microenvironment of aged thymuses, the proportions of different CD4/CD8 thymocyte subsets do not undergo significant variations. Remarkably, a strong CXCL12 expression was found in older thymuses, which appeared in the same locations as in younger thymuses: the subcapsulary and medullary areas. The proportions of CXCR4(+) cells, most of them belonging to the CD3(-) compartment, showed no important variations in the older thymuses. However, within the CD34(+) cell population, a significant reduction in the expression of CXCR4 molecules was observed.

Interplay between BMP4 and IL-7 in human intrathymic precursor cells

Bone morphogenetic proteins (BMPs) play a pivotal role during vertebrate embryogenesis and organogenesis, and have also been described to function in regulating cell fate and determination in self-renewing tissues in adults. Recent results have demonstrated that the different components of the BMP2/4 signaling pathway are expressed in the human thymus. In this study, we provide evidence that BMP4 and IL-7 interplay is important in the maintenance of the human thymic progenitor population. Intrathymic CD34(+) cells express BMP receptors (BMPRIA, BMPRIB, ActRIA, BMPRII), signal transduction molecules (Smad1, 5, 8 and 4), and produce BMP4. Neutralization of endogenous BMP4 by treatment with the antagonist Noggin reduces thymic precursor cell survival, and the addition of exogenous BMP4 decreases their proliferation. The treatment of chimeric human-mouse fetal thymus organ cultures with BMP4 inhibits cell expansion, arrests thymocyte differentiation, and leads to the accumulation of human CD34(+) precursor cells. This effect is mainly attributed to the ability of BMP4 to counteract the IL-7-induced proliferation and differentiation of CD34(+) cells. BMP4 downregulates in the precursor cell population the expression of CD127 and inhibits the IL-7-dependent STAT5 phosphorylation. In addition, BMP signaling is promoted by IL-7. Our results also demonstrate that in thymic progenitors BMPs act downstream of Sonic Hedgehog, previously described to function as a maintenance factor for human intrathymic CD34(+) precursor cells.

Transient beta-catenin stabilization modifies lineage output from human thymic CD34+CD1a- progenitors

Increasing evidence includes Wnt proteins inside the group of master-signaling pathways that govern immune and nonimmune differentiation systems, fundamental for normal development and homeostasis. Although their precise functions in bone marrow and thymus are still controversial, numerous studies have shown that Wnt signaling is able to control the proliferation of hematopoietic stem cells and thymic progenitors and might also affect their cell-fate decisions and subsequent maturation. In the present work, we analyze the effect of transient stimulation of the canonical Wnt pathway in the differentiation potential of Lin(-)CD34(+) CD1a(-) human thymic progenitors, a multipotent and heterogeneous cell population that has the capacity to develop into T cells, NK cells, monocytes, cDC, and pDC. Our results demonstrate that giving a boost to canonical Wnt signaling, triggered by transient exposure to Wnt3a or LiCl, the differentiation capacity of thymic progenitors changes, enhancing NK cell production. On the contrary, Wnt3a- or LiCl-pretreated thymic progenitors generate a significantly lower number of myeloid lineage cells, monocytes, and cDC and exhibit a reduced capacity to differentiate into pDC lineage. As a possible mechanism for this effect, we show that Wnt3a- and LiCl-pretreated progenitors change their membrane levels of receptors for cytokines pivotal for their expansion and differentiation, such as Flt3L. Moreover, canonical Wnt pathway stimulation modifies the transcription factor profile of CD34(+)CD1(-) thymocytes, increasing Hes-1 and ID3 expression levels.

The effect of malarial infection on maternal-fetal outcome in Ecuador

OBJECTIVE

To describe maternal and fetal outcome among pregnancies complicated with malarial infection.

METHODS

Charts of pregnancies complicated with malarial infection were reviewed. Parasital etiology and maternal/fetal data was analyzed.

RESULTS

During the year 2001, at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil-Ecuador, 80 pregnancies complicated with malarial infection were admitted for treatment. This rendered an incidence of 2.1 per 1,000 live births (80/37,579). Mean maternal age was 25.2 +/- 6.7 years and the 19-29 age group was the most frequently affected (50%). On admittance, fever, chills, jaundice and anemia was present in 97.5%, 78.8%, 38.8% and 60% respectively. Falciparum was the most frequently presenting species (56.3%). Patients admitted at < 20 weeks gestation (n = 17) had a 76.5% and 82.4% abortion and adverse fetal outcome rate respectively. Among those admitted at 20-36 weeks (n = 55) the rates for preterm birth, intrauterine fetal death, low birthweight (LBW) and small-for-gestational age (SGA) were 34.5%, 11%, 40.8% and 48.9% respectively. Among patients admitted > 36 weeks, 87.5% (7/8) ended in a live term delivery. Adolescents presented a higher rate of anemia and SGA neonates. The overall (n = 80) abortion, preterm delivery and intrauterine fetal demise rates were 16.3%, 25% and 8.8% respectively. Chloroquine effectively treated 98.8% of cases and there was one maternal death due to falciparum infection.

CONCLUSIONS

In this Ecuadorian population, malarial infection complicating gestation was associated to adverse maternal-fetal outcome, which was more evident among teenagers and pregnancies presenting malaria at an earlier gestational age.

The early course of kidney allograft rejection: defining the time when rejection begins

We studied the early events in mouse kidney allografts and isografts to define when allorecognition begins and when alloimmune tissue injury begins. Allografts but not isografts showed T-cell infiltration in perivascular areas from day 1, but tubulitis and arteritis did not develop until day 7. Flow cytometry confirmed the early allospecific CD3(+)CD8(+) T-cell infiltrate. At day 1, both allografts and isografts showed extensive transcriptome changes, reflecting the response to surgery, but only allografts showed expression of interferon-gamma (IFN-gamma)-inducible transcripts and T-cell-associated transcripts. Although the number of CD68(+) myeloid cell numbers did not increase in day 1 isografts or allografts, mRNA expression for myeloid markers was increased in isografts and allografts, suggesting activation of resident cells of the macrophage-dendritic cell series (MMDCs) in response to injury, followed by increased CD68(+) cell numbers from day 2. By day 3, an interstitial T-cell and MMDC infiltrate was established in allografts, corresponding with the emergence of allospecific tissue injury, as reflected by decreased parenchymal transcripts. Thus, in renal allografts, allorecognition by T cells occurs in perivascular sites by day 1, but alloimmune parenchymal damage begins at day 3, coinciding with the emergence of the interstitial T-cell-MMDC infiltrate.

CXCL12/CXCR4 signaling promotes human thymic dendritic cell survival regulating the Bcl-2/Bax ratio

CXCL12, a member of the chemokine CXC subfamily, and its physiologic receptor CXCR4 are essential for the development of various organs during embryonic development and are also involved in the control of cell survival, proliferation and migration in adult tissues. In the human thymus, CXCL12 is produced by epithelial cells located in the subcapsular and medullary regions and CXCR4 is expressed in different thymocyte subpopulations. Several results have demonstrated that CXCL12/CXCR4 signaling participates in different intrathymic processes including the control of human precursor cell survival and proliferation, and the exit of mature thymocytes to the periphery. In this study, we show that CXCL12 is also produced by human thymic dendritic cells (DCs), most of which express CXCR4 receptor. The addition of exogenous CXCL12 significantly inhibited the serum depletion-induced apoptosis in thymic DCs, and the treatment with neutralizing antibodies against CXCL12 or CXCR4 decreased their survival. The survival-promoting effect of CXCL12 was mediated by the up-regulation of Bcl-2 protein expression and the concomitant down-regulation of Bax protein expression. The higher viability of thymic DCs also enhanced their allostimulatory capacity. Taken together, the results suggest a new function of CXCL12 in the human thymus controlling the survival and functionality of thymic DCs.

Survival and function of human thymic dendritic cells are dependent on autocrine Hedgehog signaling

The Hedgehog (Hh) family of signaling molecules functions in the development of numerous tissues during embryogenesis and has also been involved in adult self-renewing tissues. Recent results have demonstrated that the different components of the Hh signaling pathway are expressed in the human thymus. In this study, we investigate whether thymic dendritic cells (DCs) are cell targets for Hh signaling. Both components of the Hh receptor, Patched and Smoothened, as well as other Hh-binding proteins with modulating functions, are expressed by human thymic DCs. The expression of Gli1, Gli2, and Gli3 transcription factors suggests that the Hh signaling pathway is active in thymic DCs, and approximately one-half of thymic DCs produces Sonic Hh (Shh). The culture of thymic DCs with Shh protects them from apoptosis [similarly to CD40 ligand (CD40L)], and these antiapoptotic effects are related to an up-regulation of Bcl-2 and Bcl-X(L) protein expression. The addition of the Hh pathway inhibitor, cyclopamine, decreases DC viability and impairs their allostimulatory function in vitro. In addition, the blockade of the Hh signaling pathway by cyclopamine treatment abrogates the up-regulation of HLA-DR, CD86, CD80, and CD83 expression induced by CD40L on thymic DCs. Finally, we also show that after activation with CD40L thymic DCs down-regulate the expression of Hh receptor components as well as Shh production. Taken together, these results suggest that the survival and function of thymic DCs are regulated by an autocrine Hh signaling.

[Orthotopic renal transplant: our experience]

Orthotopic renal transplant (ORT) is useful in cases of severe atherosclerosis, heterotopic bilateral transplant, unsuitable pelvic vessels and in aortic thrombosis, but it is not available in all the institutions and it is only realized of exceptional form.

AIM

To review the indication, surgical technique and outcome of the ORT at our hospital.

MATERIAL AND METHODS

The studied included five cases between January 1990 and December 2005. We analyzed several variables: demographic characteristics, characteristics of the donor, ischemia times, evolution of renal function and morbi-mortality associated.

RESULTS

Left ORT was performed in three men and two women. Mean patient age was 52+/-5 years, all the patients received kidneys from cadaveric donors. Mean creatinine and urea one month postoperative were 2.2+/-0.72 mg/dl and 103+/-17.2 mg/dl and at 6 months postoperative were 1.8+/-0.59 mg/dl and 78+/-14 mg/dl respectively. Immediately all patients received prophylaxis with low molecular weight heparin but it was indicated antiaggregation to two patients when they left the hospital, anticoagulation to two patients and to one of them was decided to anticoagulation nor antiagregation for history of bled digestive. A patient died for bleeding episode at level of the renal graft six months after the transplant, she was in treatment with dicumarinics, they were indicated by venous deep thrombosis in right leg. The survival a year is 80 % of the graft and the patient. Only two patients returned to hospital later, one of them for presenting an episode of diverticulitis and the other one for renal obstructive failure that needed laying of catheter pig-tail. Four patients presented stenosis of renal native vassels detected in control magnetic nuclear resonance, not symptomatic. There are two patients who take more than three years transplanted with renal stable function (creatinina 1.3 mg/dl and 1.4 mg/dl respectively).

CONCLUSION

ORT is an excellent option in patients with co-morbidity increased for atherosclerosis and that cannot be placed in the iliac fossaes.

Knowledge and practice of family planning and HIV-prevention behaviour among just delivered adolescents in Ecuador: the problem of adolescent pregnancies

BACKGROUND

Adolescents constitute a high risk population for the spreading of sexually transmitted diseases, among them HIV/AIDS. Knowledge regarding reproductive issues among them is a key point in order to establish appropriate prevention programs.

OBJECTIVE

Obtain information regarding the knowledge and practice related to family planning and HIV-prevention behaviour among adolescents of low income.

METHODS

Adolescents aged 19 or less delivering at the Enrique C. Sotomayor Obstetrics and Gynecology Hospital, Guayaquil, Ecuador were surveyed in the immediate postpartum period with a structured questionnaire designed for the purpose.

RESULTS

During the study period, 357 pregnant adolescents were surveyed. Mean age was 17.2 +/- 1.4 years, 30.8% were aged 16 or less. Demographical and obstetrical history differences were found when comparing adolescents in relation to age and educational level. A high rate of mothers had unplanned pregnancies (63.3%) or did not know what family planning was (49.6%). Despite high knowledge of what a condom or an oral contraceptive was, few had used them in the past. The most frequently known family planning methods in this series, which was age dependent, were: oral contraceptives (90.2%), condoms (84.9%), parenteral (66.7%) and intrauterine devices (63.3%). The majority knew what HIV/AIDS infection was, the most important sources of knowledge being: television, high school source, and family or relatives. A high rate of adolescents had never had an HIV test performed in the past with one prior tested adolescent resulting in a positive result. There was a high rate of knowledge regarding the most frequent HIV transmission routes: sexual intercourse, contact with infected blood and vertical transmission. In this series, although condom use was the most known way for HIV protection, only 22.2% answered having intercourse protected with this method.

CONCLUSION

In this adolescent series, older age was related to higher knowledge in family planning methods; in global despite finding a relatively high knowledge in family planning and HIV related issues, contraception use and HIV protection behaviour was low.