KIR2DS1 and KIR2DL1-C245 Dominantly Repress NK Cell Degranulation Triggered by Monoclonal or Bispecific Antibodies, whereas Education by Uptuning Inhibitory Killer Ig-related Receptors Exerts No Advantage in Ab-dependent Cellular Cytotoxicity.

NK cell responsiveness to target cells is tuned by interactions between inhibitory NK cell receptors and their cognate HLA class I ligands in a process termed "NK cell education." Previous studies addressing the role for NK cell education in Ab-dependent cellular cytotoxicity (ADCC) show ambiguous results and do not encompass full educational resolution. In this study, we systematically characterized human NK cell CD16-triggered degranulation toward defined human tumor cell lines in the presence of either the mAb rituximab or a recently developed CD34xCD16 bispecific killer engager. Despite positive correlation between killer Ig-related receptor (KIR)-mediated education and CD16 expression, NK cells educated by one or even two inhibitory KIRs did not perform better in terms of ADCC than uneducated NK cells in either missing-self or KIR-ligand matched settings at saturating Ab concentrations. Instead, NKG2A+ NK cells consistently showed more potent ADCC in the missing-self context despite lower levels of CD16 expression. KIR2DS1+ NK cells demonstrated dampened ADCC in both the missing-self and KIR-ligand matched settings, even in the presence of its ligand HLA C2. The lower response by KIR2DS1+ NK cells was also observed when stimulated with a bispecific killer engager. Surprisingly, repression of ADCC was also observed by NKG2A+ NK cells coexpressing the inhibitory KIR2DL1-C245 receptor that confers weak education. In conclusion, our study suggests that NK cell education by inhibitory KIRs does not augment ADCC per se, whereas expression of KIR2DS1 and KIR2DL1-C245 dominantly represses ADCC. These insights add to the fundamental understanding of NK cells and may have implications for their therapeutic use.

The Self-reference Effect Can Modulate Language Syntactic Processing Even Without Explicit Awareness: An Electroencephalography Study.

Although it is well established that self-related information can rapidly capture our attention and bias cognitive functioning, whether this self-bias can affect language processing remains largely unknown. In addition, there is an ongoing debate as to the functional independence of language processes, notably regarding the syntactic domain. Hence, this study investigated the influence of self-related content on syntactic speech processing. Participants listened to sentences that could contain morphosyntactic anomalies while the masked face identity (self, friend, or unknown faces) was presented for 16 msec preceding the critical word. The language-related ERP components (left anterior negativity [LAN] and P600) appeared for all identity conditions. However, the largest LAN effect followed by a reduced P600 effect was observed for self-faces, whereas a larger LAN with no reduction of the P600 was found for friend faces compared with unknown faces. These data suggest that both early and late syntactic processes can be modulated by self-related content. In addition, alpha power was more suppressed over the left inferior frontal gyrus only when self-faces appeared before the critical word. This may reflect higher semantic demands concomitant to early syntactic operations (around 150-550 msec). Our data also provide further evidence of self-specific response, as reflected by the N250 component. Collectively, our results suggest that identity-related information is rapidly decoded from facial stimuli and may impact core linguistic processes, supporting an interactive view of syntactic processing. This study provides evidence that the self-reference effect can be extended to syntactic processing.

The proteomic signature of circulating extracellular vesicles following intracerebral hemorrhage: Novel insights into mechanisms underlying recovery.

Circulating extracellular vesicles (EVs) can participate in innate repair processes triggered after intracerebral hemorrhage (ICH). We aimed to describe changes in the proteomic profile of circulating EVs between the acute and subacute phases of ICH and to compare the findings depending on outcomes, as an approach to unraveling such repair mechanisms. This was a prospective observational study including patients with non-traumatic supratentorial ICH. Exclusion criteria were previous disability, signs of herniation on baseline computed tomography, or limited life expectancy. EVs were isolated from blood samples at 24 h and 7 days after symptom onset. After 6-months' follow-up, patients were dichotomized into poor and good outcomes, defining good as an improvement of >10 points or > 50 % on the National Institutes of Health Stroke Scale and a modified Rankin Scale of 0-2. The protein cargo was analyzed by quantitative mass spectrometry and compared according to outcomes. Forty-four patients completed follow-up, 16 (35.5 %) having good outcomes. We identified 1321 proteins in EVs, 37 with differential abundance. In patients with good outcomes, proteins related to stress response (DERA, VNN2, TOMM34) and angiogenesis (RHG01) had increased abundance at 7 days. EVs from patients with poor outcomes showed higher levels of acute-phase reactants (CRP, SAA2) at 7 days compared with 24 h. In conclusion, the protein content of circulating EVs in patients with ICH changes over time, the changes varying depending on the clinical outcome, with greater abundance of proteins potentially involved in the repair processes of patients with good outcomes.

Brain and immune system-derived extracellular vesicles mediate regulation of complement system, extracellular matrix remodeling, brain repair and antigen tolerance in Multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is an immune-mediated central nervous system disease whose course is unpredictable. Finding biomarkers that help to better comprehend the disease's pathogenesis is crucial for supporting clinical decision-making. Blood extracellular vesicles (EVs) are membrane-bound particles secreted by all cell types that contain information on the disease's pathological processes. PURPOSE: To identify the immune and nervous system-derived EV profile from blood that could have a specific role as biomarker in MS and assess its possible correlation with disease state. RESULTS: Higher levels of T cell-derived EVs and smaller size of neuron-derived EVs were associated with clinical relapse. The smaller size of the oligodendrocyte-derived EVs was related with motor and cognitive impairment. The proteomic analysis identified mannose-binding lectin serine protease 1 and complement factor H from immune system cell-derived EVs as autoimmune disease-associated proteins. We observed hepatocyte growth factor-like protein in EVs from T cells and inter-alpha-trypsin inhibitor heavy chain 2 from neurons as white matter injury-related proteins. In patients with MS, a specific protein profile was found in the EVs, higher levels of alpha-1-microglobulin and fibrinogen ß chain, lower levels of C1S and gelsolin in the immune system-released vesicles, and Talin-1 overexpression in oligodendrocyte EVs. These specific MS-associated proteins, as well as myelin basic protein in oligodendrocyte EVs, correlated with disease activity in the patients with MS. CONCLUSION: Neural-derived and immune-derived EVs found in blood appear to be good specific biomarkers in MS for reflecting the disease state.

Antibody Content against Epstein-Barr Virus in Blood Extracellular Vesicles Correlates with Disease Activity and Brain Volume in Patients with Relapsing-Remitting Multiple Sclerosis.

We aimed to analyze whether EVs carry antibodies against EBV antigens and the possibility that they could serve as diagnostic and disease activity blood biomarkers in RRMS. This was a prospective and observational study including patients with RRMS with active and inactive disease and healthy controls. Blood EVs were isolated by precipitation. Titers of antibodies against nuclear (anti-EBNA1) and capsid (anti-VCA) EBV antigens in EVs and in plasma, as well as content of myelin antibodies in EVs were determined by ELISA. An exploratory analysis of correlations with clinical and radiological data was performed. Patients with RRMS had higher titers of anti-VCA inside EVs and free in plasma than healthy controls. Patients with active disease showed higher levels of anti-EBNA1 in EVs, but not in plasma, than patients with inactive disease. EV anti-VCA levels correlated with disease duration and with decreased brain volume structures-total brain, white matter, gray matter, cerebellum, hippocampus, -but not with T2/FLAIR lesion volume or EDSS, SDMT, or 9HPT. In addition, EV anti-VCA correlated with EV anti-MBP. The anti-VCA and anti-EBNA1 content in EVs could represent diagnostic and disease activity blood biomarkers, respectively, in RRMS.

Altered electromyographic responses to emotional and pain information in awake bruxers: case-control study.

OBJECTIVES: This study aims to investigate how emotional information and pain-related information affect the activity of the masticatory muscles in participants with awake bruxism and controls. MATERIAL AND METHODS: Different videos and texts, with positive, negative, and neutral valence or related to pain, were presented to a sample of university students, while their electromyographic (EMG) activity around the masseter muscle and their skin conductance were recorded. Two groups were selected, with 24 subjects each: one group of subjects with definitive awake bruxism (confirmed by posterior EMG activity) who also suffered from moderate jaw discomfort, and another group of subjects without bruxism. RESULTS: The results demonstrated that the subjects with definitive awake bruxism displayed greater muscular activity when presented videos and texts with negative valence, especially when related to pain, than the non-bruxist group. CONCLUSIONS: This study supports the idea that persons with bruxism who also suffer moderate levels of jaw discomfort present greater bruxism activity when watching pain-related stimuli, and to a lesser extent when watching negative stimuli. CLINICAL RELEVANCE: The increased muscular activity induced by negative and pain-related information might contribute to pain exacerbation and perpetuation in persons with bruxism who suffer from discomfort.

Bacterial Panicle Blight and Burkholderia glumae: From Pathogen Biology to Disease Control.

Bacterial panicle blight (BPB), caused by the bacterium Burkholderia glumae, has affected rice production worldwide. Despite its importance, neither the disease nor the causal agent are well understood. Moreover, methods to manage BPB are still lacking. Nevertheless, the emerging importance of this pathogen has stimulated research to identify the mechanisms of pathogenicity, to gain insight into plant disease resistance, and to develop strategies to manage the disease. In this review, we consolidate current information regarding the virulence factors that have been identified in B. glumae and present a model of the disease and the pathogen. We also provide an update on the current research status to develop methods to control the disease especially through biological control approaches and through the development of resistant cultivars.

Potential Roles of Extracellular Vesicles as Biomarkers and a Novel Treatment Approach in Multiple Sclerosis.

Extracellular vesicles (EVs) are a heterogeneous group of bilayer membrane-wrapped molecules that play an important role in cell-to-cell communication, participating in many physiological processes and in the pathogenesis of several diseases, including multiple sclerosis (MS). In recent years, many studies have focused on EVs, with promising results indicating their potential role as biomarkers in MS and helping us better understand the pathogenesis of the disease. Recent evidence suggests that there are novel subpopulations of EVs according to cell origin, with those derived from cells belonging to the nervous and immune systems providing information regarding inflammation, demyelination, axonal damage, astrocyte and microglia reaction, blood-brain barrier permeability, leukocyte transendothelial migration, and ultimately synaptic loss and neuronal death in MS. These biomarkers can also provide insight into disease activity and progression and can differentiate patients' disease phenotype. This information can enable new pathways for therapeutic target discovery, and consequently the development of novel treatments. Recent evidence also suggests that current disease modifying treatments (DMTs) for MS modify the levels and content of circulating EVs. EVs might also serve as biomarkers to help monitor the response to DMTs, which could improve medical decisions concerning DMT initiation, choice, escalation, and withdrawal. Furthermore, EVs could act not only as biomarkers but also as treatment for brain repair and immunomodulation in MS. EVs are considered excellent delivery vehicles. Studies in progress show that EVs containing myelin antigens could play a pivotal role in inducing antigen-specific tolerance of autoreactive T cells as a novel strategy for the treatment as "EV-based vaccines" for MS. This review explores the breakthrough role of nervous and immune system cell-derived EVs as markers of pathological disease mechanisms and potential biomarkers of treatment response in MS. In addition, this review explores the novel role of EVs as vehicles for antigen delivery as a therapeutic vaccine to restore immune tolerance in MS autoimmunity.

Type 1 Diabetes Care in Mexico: An Analysis of the RENACED-DT1 National Registry.

BACKGROUND: Information regarding diagnosis, treatment, and follow-up of patients with type 1 diabetes (PWT1D) in Mexico is limited. We developed an on-line platform Registro Nacional de Pacientes con Diabetes Tipo 1 (RENACED-DT1). OBJECTIVE: The objective of the study was to describe the characteristics and healthcare of PWT1D registered in RENACED-DT1. METHODS: Analyses of 965 PWT1D from July 2014 to January 2018 in different endocrinology clinics around Mexico. RESULTS: Sixty-one percent were female with median age of 21 years, age at diagnosis 11 years, and disease duration at inclusion 8.2 years. Treatment regimen was basal-bolus in 61% and insulin-pumps in 21% (mainly in the private sector); 33.3% with self-monitoring of blood-glucose (SMBG) ≥4 times/day. Mean HbA1c at last follow-up was 8.7 ± 2.1% (72±23 mmol/mol), 18% had HbA1c < 7% (53 mmol/mol), and 35% > 9% (75 mmol/mol). SMBG ≥ 4 times/day was associated with HbA1c < 7%. Time since diagnosis > 10 years, female sex, BMI ≥ 30 kg/m2, SMBG < 4 times/day, and any hypoglycemia were associated with microvascular complications (p < 0.05). CONCLUSIONS: Percentage of patients achieving HbA1c < 7% is low; increased blood glucose monitoring is associated with better glycemic control. The achievement of optimal glycemic control must be increased to reduce the incidence of chronic complications and improve quality of life in PWT1D.

Mesenchymal Stem Cells From Adipose Tissue Do not Improve Functional Recovery After Ischemic Stroke in Hypertensive Rats.

Background and Purpose- Hypertension is the most frequent comorbidity in stroke.The purpose of this study was to evaluate whether hypertension alters the response to treatment with adipose tissue-derived mesenchymal stem cells (ADMSCs) after an ischemic stroke in rats. Methods- Ischemic stroke was induced in male normotensive or hypertensive rats. Either vehicle or 1×106 ADMSC was intravenously administered at 48 hours poststroke. Functional outcome, lesion size and volume, and markers of brain repair (GFAP [glial fibrillary acidic protein], doublecortin, CD-31, α-smooth muscle actin) were evaluated. Results- Hypertensive rats had larger lesions, higher apparent diffusion coefficients (ADC) and worse functional outcomes than normotensive rats. Hypertension increased GFAP and vascular markers (CD-31 and α-smooth muscle actin). The hypertensive rats treated with ADMSC did not show any significant improvement in functional recovery, lesion size, ADC values, or histological markers compared with those which received the vehicle. Conclusions- ADMSC did not reverse the hypertension-induced increase in lesion severity or functional impairment. Gliosis, neurogenesis, or vascular markers were not affected by ADMSC in hypertensive rats. Hypertension has a negative impact on the therapeutic effect of ADMSC after an ischemic stroke.

Etiology and Prognosis of Pneumonia in Patients with Solid Tumors: A Prospective Cohort of Hospitalized Cases.

BACKGROUND: Data on the incidence, etiology, and prognosis of non-ventilator-associated pneumonia in hospitalized patients with solid tumors are scarce. We aimed to study the characteristics of non-ventilator-associated pneumonia in hospitalized patients with solid tumors. MATERIALS AND METHODS: This was a prospective noninterventional cohort study of pneumonia in patients hospitalized in an oncology ward in a tertiary teaching hospital. Pneumonia was defined according to the American Thoracic Society criteria. Patients were followed for 1 month after diagnosis or until discharge. Survivors were compared with nonsurvivors. RESULTS: A total of 132 episodes of pneumonia were diagnosed over 1 year (9.8% of admissions to the oncology ward). They were health care-related (67.4%) or hospital-acquired pneumonia (31.8%). Lung cancer was the most common malignancy. An etiology was established in 48/132 episodes (36.4%). Knowing the etiology led to changes in antimicrobial therapy in 58.3%. Subsequent intensive care unit admission was required in 10.6% and was linked to inappropriate empirical therapy. Ten-day mortality was 24.2% and was significantly associated with hypoxia (odds ratio [OR], 2.1). Thirty-day mortality was 46.2%. The independent risk factors for 30-day mortality were hypoxia (OR, 3.3), hospital acquisition (OR, 3.1), and a performance status >1 (OR, 2.6). Only 40% of patients who died within 30 days were terminally ill. CONCLUSION: Pneumonia is a highly prevalent condition in hospitalized patients with solid tumors, even with nonterminal disease. Etiology is diverse, and poor outcome is linked to inappropriate empirical therapy. Efforts to get the empirical therapy right and reach an etiological diagnosis to subsequently de-escalate are warranted. IMPLICATIONS FOR PRACTICE: The present study shows that pneumonia is a prevalent infectious complication in patients admitted to oncology wards, with a very high mortality, even in non-terminally ill patients. Etiology is diverse, and etiological diagnosis is reached in fewer than 40% of cases in nonintubated patients. Intensive care unit admission, a marker of poor outcome, is associated with inappropriate empirical therapy. These results suggest that, to improve prognosis, a more precise and appropriate antimicrobial empirical therapy for pneumonia in patients with solid tumors is necessary, together with an effort to reach an etiological diagnosis to facilitate subsequent de-escalation.

Glycemic variability: prognostic impact on acute ischemic stroke and the impact of corrective treatment for hyperglycemia. The GLIAS-III translational study.

INTRODUCTION: Glycemic variability (GV) represents the amplitude of oscillations in glucose levels over time and is associated with higher mortality in critically ill patients. Our aim is to evaluate the impact of GV on acute ischemic stroke (IS) outcomes in humans and explore the impact of two different insulin administration routes on GV in an animal model. METHODS: This translational study consists of two studies conducted in parallel: The first study is an observational, multicenter, prospective clinical study in which 340 patients with acute IS will be subcutaneously implanted a sensor to continuously monitor blood glucose levels for 96 h. The second study is a basic experimental study using an animal model (rats) with permanent occlusion of the middle cerebral artery and induced hyperglycemia (through an intraperitoneal injection of nicotinamide and streptozotocin). The animal study will include the following 6 groups (10 animals per group): sham; hyperglycemia without IS; IS without hyperglycemia; IS and hyperglycemia without treatment; IS and hyperglycemia and intravenous insulin; and IS and hyperglycemia and subcutaneous insulin. The endpoint for the first study is mortality at 3 months, while the endpoints for the animal model study are GV, functional recovery and biomarkers. DISCUSSION: The GLIAS-III study will be the first translational approach analyzing the prognostic influence of GV, evaluated by the use of subcutaneous glucose monitors, in acute stroke. Trial registration https://www.clinicaltrials.gov (NCT04001049).

Neural Dynamics in the Processing of Personal Objects as an Index of the Brain Representation of the Self.

Across time, personal belongings incorporate semantic self-knowledge contributing to the subjective meaning of mineness and preference, whose access is prioritized. Although neuroimaging is starting to explore self-knowledge processes, more research is still necessary to better understand many aspects of these processes. One, the timing of the mechanisms involved, is the main purpose of the present study. Here, we investigate the differential patterns of event-related brain potentials and the underlying dynamic causal connectivity between neural generators to self-related objects ranging in self-relevance, as compared to non-personal-related objects. Personal objects elicited lower N2 and higher P3 components compared to non-personal objects, and those with high relevance showed the lowest N2 and the highest P3 amplitudes. Brain sources connectivity corresponding to N2-P3 ERP complex revealed an early connectivity between posterior cingulate/precuneus and parahippocampal gyrus, common for both types of objects. However, this parietal connectivity was kept in later latencies only for personal objects, also intervening the anterior cingulate as the main driver of information flow to the parietal network. Personal objects showed more extensive connectivity between parietal areas and these with anterior cingulate. These findings provide new evidence of a neural connectivity and its temporal course underlying the interplay of lower-level and higher-level cognitive processes relative to personal objects. Further, the results offer new insights on how superordinate mental representations enable distinctive processing of relevant belongings, starting relatively early in time.

Harnessing Pseudomonas protegens to Control Bacterial Panicle Blight of Rice.

Bacterial panicle blight of rice is a seedborne disease caused by the bacterium Burkholderia glumae. This disease has affected rice production worldwide and its effects are likely to become more devastating with the continuous increase in global temperatures, especially during the growing season. The bacterium can cause disease symptoms in different tissues and at different developmental stages. In reproductive stages, the bacterium interferes with grain development in the panicles and, as a result, directly affects rice yield. Currently, there are no methods to control the disease because chemical control is not effective and completely resistant cultivars are not available. Thus, a promising approach is the use of antagonistic microorganisms. In this work, we identified one strain of Pseudomonas protegens and one strain of B. cepacia with antimicrobial activity against B. glumae in vitro and in planta. We further characterized the antimicrobial activity of P. protegens and found that this activity is associated with bacterial secretions. Cell-free secretions from P. protegens inhibited the growth of B. glumae in vitro and also prevented B. glumae from causing disease in rice. Although the specific molecules associated with these activities have not been identified, these findings suggest that the secreted fractions from P. protegens could be harnessed as biopesticides to control bacterial panicle blight of rice.

Neurofunctional characterization of early prefrontal processes contributing to interpersonal guilt.

Guilt is a social emotion that plays a central role in promoting prosocial behavior. Despite its relevance, it remains poorly understood. The present study aimed to fill this gap by verifying and characterizing a frontal negative fluctuation of the event-related brain potentials (ERP) emerging in conditions of interpersonal guilt. Paired participants would earn money if both performed correctly a dot estimation task (both right); otherwise, both would lose a similar amount (self wrong, partner wrong, and both wrong conditions). The reported feeling of guilt was noticeable in the self wrong condition, which yielded a frontal negativity between 300 and 500 ms after the onset of performance feedback. The amplitude of this fluctuation, however, did not correlate with the amount of guilt reported by the participants, whereas both these values did so with standard measures of empathy. Neither anxiety (trait or state) nor arousal (skin conductance response) seemed to relate to this negativity. A neural source (LORETA) analysis established its generators in the dorsal medial prefrontal cortex (mPFC), a region linked to guilt in fMRI studies but also, importantly, to empathy. The frontal negative fluctuation thus might reflect empathic processes contributing to achieve feelings of interpersonal guilt.

Circulating Monocytes Exhibit an Endotoxin Tolerance Status after Acute Ischemic Stroke: Mitochondrial DNA as a Putative Explanation for Poststroke Infections.

Patients with acute ischemic stroke (AIS) suffer from infections associated with mortality. The relevance of the innate immune system, and monocytes in particular, has emerged as an important factor in the evolution of these infections. The study enrolled 14 patients with AIS, without previous treatment, and 10 healthy controls. In the present study, we show that monocytes from patients with AIS exhibit a refractory state or endotoxin tolerance. The patients were unable to orchestrate an inflammatory response against LPS and expressed three factors reported to control the evolution of human monocytes into a refractory state: IL-1R-associated kinase-M, NFkB2/p100, and hypoxia-inducible factor-1α. The levels of circulating mitochondrial DNA (mtDNA) in patients with AIS correlated with impaired inflammatory response of isolated monocytes. Interestingly, the patients could be classified into two groups: those who were infected and those who were not, according to circulating mtDNA levels. This finding was validated in an independent cohort of 23 patients with AIS. Additionally, monocytes from healthy controls, cultured in the presence of both sera from patients and mtDNA, reproduced a refractory state after endotoxin challenge. This effect was negated by either a TLR9 antagonist or DNase treatment. The present data further extend our understanding of endotoxin tolerance implications in AIS. A putative role of mtDNA as a new biomarker of stroke-associated infections, and thus a clinical target for preventing poststroke infection, has also been identified.

Magnetic targeting of adoptively transferred tumour-specific nanoparticle-loaded CD8+ T cells does not improve their tumour infiltration in a mouse model of cancer but promotes the retention of these cells in tumour-draining lymph nodes.

BACKGROUND: Adoptive T cell-transfer (ATC) therapy is a highly promising cancer-treatment approach. However, in vivo-administered T cells tend to disperse, with only a small proportion reaching the tumour. To remedy this, magnetic targeting of T cells has been recently explored. Magnetic nanoparticles (MNPs) functionalised with antibodies were attached to effector T cells and magnetically recruited to tumour sites under MRI guidance. In this study, we investigated whether 3-aminopropyl-triethoxysilane (APS)-coated MNPs directly attached to CD8+ T cell membranes could also magnetically target and accumulate tumour-specific CD8+ T cells in solid tumours using an external magnetic field (EMF). As it has been shown that T cells associated with APS-coated MNPs are retained in lymph nodes (LNs), and tumour-draining LNs are the most common sites of solid-tumour metastases, we further evaluated whether magnetic targeting of APS-MNP-loaded CD8+ T cells could cause them to accumulate in tumour-draining LNs. RESULTS: First, we show that antigen-specific CD8+ T cells preserve their antitumor activity in vitro when associated with APS-MNPs. Next, we demonstrate that the application of a magnetic field enhanced the retention of APS-MNP-loaded OT-I CD8+ T cells under flow conditions in vitro. Using a syngeneic mouse model, we found similar numbers of APS-MNP-loaded OT-I CD8+ T cells and OT-I CD8+ T cells infiltrating the tumour 14 days after cell transfer. However, when a magnet was placed near the tumour during the transfer of tumour-specific APS-MNP-loaded CD8+ T cells to improve tumour infiltration, a reduced percentage of tumour-specific T cells was found infiltrating the tumour 14 days after cell transfer, which was reflected in a smaller reduction in tumour size compared to tumour-specific CD8+ T cells transferred with or without MNPs in the absence of a magnetic field. Nonetheless, magnet placement near the tumour site during cell transfer induced infiltration of activated tumour-specific CD8+ T cells in tumour-draining LNs, which remained 14 days after cell transfer. CONCLUSIONS: The use of an EMF to improve targeting of tumour-specific T cells modified with APS-MNPs reduced the percentage of these cells infiltrating the tumour, but promoted the retention and the persistence of these cells in the tumour-draining LNs.

T cells loaded with magnetic nanoparticles are retained in peripheral lymph nodes by the application of a magnetic field.

BACKGROUND: T lymphocytes are highly dynamic elements of the immune system with a tightly regulated migration. T cell-based transfer therapies are promising therapeutic approaches which in vivo efficacy is often limited by the small proportion of administered cells that reaches the region of interest. Manipulating T cell localisation to improve specific targeting will increase the effectiveness of these therapies. Nanotechnology has been successfully used for localized release of drugs and biomolecules. In particular, magnetic nanoparticles (MNPs) loaded with biomolecules can be specifically targeted to a location by an external magnetic field (EMF). The present work studies whether MNP-loaded T cells could be targeted and retained in vitro and in vivo at a site of interest with an EMF. RESULTS: T cells were unable to internalize the different MNPs used in this study, which remained in close association with the cell membrane. T cells loaded with an appropriate MNP concentration were attracted to an EMF and retained in an in vitro capillary flow-system. MNP-loaded T cells were also magnetically retained in the lymph nodes after adoptive transfer in in vivo models. This enhanced in vivo retention was in part due to the EMF application and to a reduced circulating cell speed within the organ. This combined use of MNPs and EMFs did not alter T cell viability or function. CONCLUSIONS: These studies reveal a promising approach to favour cell retention that could be implemented to improve cell-based therapy.

Polyethylenimine-coated superparamagnetic iron oxide nanoparticles impair in vitro and in vivo angiogenesis.

Endothelial cells are essential to tumor vascularization and impairing their activity can potentially limit tumor growth. Since polyethylenimine (PEI)-coated superparamagnetic iron oxide nanoparticles (SPIONs) are bioactive nanosystems that modulate inflammatory macrophage responses and limit tumor cell invasion, we evaluated their effects on endothelial cell angiogenesis. PEI-SPION triggered proinflammatory gene profiles in a murine endothelial cell line and in primary human umbilical cord vein endothelial cells (HUVECs). These nanoparticles impaired endothelial cell migration and inhibited HUVEC tube formation. Magnetically tumor-targeted PEI-SPIONs reduced tumor vessel numbers and promoted intratumor macrophage infiltration in a tumor xenograft model. PEI-SPION treatment impaired M2 macrophage-promoted tube formation and affected HUVEC cytoskeleton by limiting Src and Cortactin activation. These mechanisms could contribute to PEI-SPION in vitro and in vivo antiangiogenic potential. These data confirm that PEI-SPION administration and application of a localized magnetic field could offer an affordable anti-angiogenic anti-tumoral targeted treatment that would complement other therapies.

Two Chloroplast-Localized Proteins: AtNHR2A and AtNHR2B, Contribute to Callose Deposition During Nonhost Disease Resistance in Arabidopsis.

Plants are naturally resistant to most pathogens through a broad and durable defense response called nonhost disease resistance. Nonhost disease resistance is a complex process that includes preformed physical and chemical barriers and induced responses. In spite of its importance, many components of nonhost disease resistance remain to be identified and characterized. Using virus-induced gene silencing in Nicotiana benthamiana, we discovered a novel gene that we named NbNHR2 (N. benthamiana nonhost resistance 2). NbNHR2-silenced plants were susceptible to the nonadapted pathogen Pseudomonas syringae pv. tomato T1, which does not cause disease in wild-type or nonsilenced N. benthamiana plants. We found two orthologous genes in Arabidopsis thaliana: AtNHR2A and AtNHR2B. Similar to the results obtained in N. benthamiana, Atnhr2a and Atnhr2b mutants were susceptible to the nonadapted bacterial pathogen of A. thaliana, P. syringae pv. tabaci. We further found that these mutants were also defective in callose deposition. AtNHR2A and AtNHR2B fluorescent protein fusions transiently expressed in N. benthamiana localized predominantly to chloroplasts and a few unidentified dynamic puncta. RFP-AtNHR2A and AtNHR2B-GFP displayed overlapping signals in chloroplasts, indicating that the two proteins could interact, an idea supported by coimmunoprecipitation studies. We propose that AtNHR2A and AtNHR2B are new components of a chloroplast-signaling pathway that activates callose deposition to the cell wall in response to bacterial pathogens.