Maintenance Of Tolerance Research Articles

Uterine NK cell functions at maternal-fetal interface†.

During pregnancy, maternal decidual tissue interacts with fetal trophoblasts. They constitute the maternal-fetal interface responsible for supplying nutrition to the fetus. Uterine natural killer (uNK) cells are the most abundant immune cells at the maternal-fetal interface during early pregnancy and play critical roles throughout pregnancy. This review provides current knowledge about the functions of uNK cells. uNK cells have been shown to facilitate remodeling of the spiral artery, control the invasion of extravillous trophoblast (EVT) cells, contribute to the induction and maintenance of immune tolerance, protect against pathogen infection, and promote fetal development. Pregnancy-trained memory of uNK cells improves subsequent pregnancy outcomes. In addition, this review describes the distinct functions of three uNK cell subsets: CD27-CD11b-, CD27+, and CD27-CD11b+ uNK cells.

Organ-specific symptom patterns during oral food challenge in children with peanut and tree nut allergy.

Peanut and tree nut allergies are common in childhood and often severe in nature. The clinical picture shows a wide variety of symptoms. To analyze the distribution of clinical symptoms and severity during oral food challenges (OFC) in children. Analysis of 1.013 prospectively recorded, positive OFCs with peanut (n=607), hazelnut (n=266), walnut (n=97), and cashew (n=43). Symptoms were categorized as immediate-type skin, gastrointestinal, upper and lower respiratory, cardiovascular symptoms, and eczema exacerbation. Symptom severity and treatment were recorded. Skin symptoms presented in 78%, followed by gastrointestinal (47%), upper (42%), and lower respiratory symptoms (32%). Cardiovascular symptoms presented in 6%. In three-quarter of the reactions, more than one organ was involved. Importantly, severe reactions occurred at every dose level. Peanut- and cashew-allergic patients had a higher relative risk of gastrointestinal symptoms compared with hazelnut- and walnut-allergic patients. Patients without vomiting had a 1.7 times higher risk developing immediate-type skin and/or lower respiratory symptoms. Three-quarter of the patients ever had eczema but worsening presented in only 10.5% of the OFCs. In patients with multiple food allergies, organs involved, eliciting dose and severity differed between allergens. Although comparisons between allergen groups with different clinical history, severity, comorbidities and laboratory data are difficult and might contain bias, our data confirm the high allergenic potential of peanut and tree nuts. The rare occurrence of eczema worsening emphasizes that avoidance diets of peanuts and tree nuts to cure eczema seem to be unnecessary and may hamper tolerance maintenance.

Pregnancy and Tumour: The Parallels and Differences in Regulatory T Cells.

Immunological tolerance plays a critical role during pregnancy as semi-allogeneic fetus must be protected from immune responses during the gestational period. Regulatory T cells (Tregs), a subpopulation of CD4+ T cells that express transcription factor Foxp3, are central to the maintenance of immunological tolerance and prevention of autoimmunity. Tregs are also known to accumulate at placenta in uterus during pregnancy, and they confer immunological tolerance at maternal-fetal interface by controlling the immune responses against alloantigens. Thus, uterine Tregs help in maintaining an environment conducive for survival of the fetus during gestation, and low frequency or dysfunction of Tregs is associated with recurrent spontaneous abortions and other pregnancy-related complications such as preeclampsia. Interestingly, there are many parallels in the development of placenta and solid tumours, and the tumour microenvironment is considered to be somewhat similar to that at maternal-fetal interface. Moreover, Tregs play a largely similar role in tumour immunity as they do at placenta- they create a tolerogenic system and suppress the immune responses against the cells within tumour and at maternal-fetal interface. In this review, we discuss the role of Tregs in supporting the proper growth of the embryo during pregnancy. We also highlight the similarities and differences between Tregs at maternal-fetal interface and tumour Tregs, in an attempt to draw a comparison between their roles in these two physiologic and pathologic states.

Tolerance induction through non-avoidance to prevent persistent food allergy (TINA) in children and adults with peanut or tree nut allergy: rationale, study design and methods of a randomized controlled trial and observational cohort study

BackgroundPeanuts (PN) and tree nuts (TN) are among the most frequent elicitors of food allergy and can lead to life-threatening reactions. The current advice for allergic patients is to strictly avoid the offending food independently of their individual threshold level, whereas sensitized patients without allergic symptoms should frequently consume the food to avoid (re-)development of food allergy. The aim of this trial is to investigate (I) whether the consumption of low allergen amounts below the individual threshold may support natural tolerance development and (II) to what extent regular allergen consumption in sensitized but tolerant subjects prevents the (re-)development of PN or TN allergy.MethodsThe TINA trial consisting of (part I) a randomized, controlled, open, parallel group, single-center, superiority trial (RCT), and (part II) a prospective observational exploratory cohort study. Children and adults (age 1–67 years) with suspected or known primary PN and/or TN allergy will undergo an oral food challenge (OFC) to determine their clinical reactivity and individual threshold. In the RCT, 120 PN or TN allergic patients who tolerate ≥100 mg of food protein will be randomized (1:1 ratio) to consumption of products with low amounts of PN or TN on a regular basis or strict avoidance for 1 year. The consumption group will start with 1/100 of their individual threshold, increasing the protein amount to 1/50 and 1/10 after 4 and 8 months, respectively. The primary endpoint is the clinical tolerance to PN or TN after 1 year assessed by OFC. In the cohort study, 120 subjects sensitized to PN and/or TN but tolerant are advised to regularly consume the food and observed for 1 year. The primary endpoint is the maintenance of clinical tolerance to PN and/or TN after 1 year assessed by challenging with the former tolerated cumulative dose.DiscussionThis clinical trial will help to determine the impact of allergen consumption versus avoidance on natural tolerance development and whether the current dietary advice for PN or TN allergic patients with higher threshold levels is still valid.Trial registrationGerman Clinical Trials Register; ID: DRKS00016764 (RCT), DRKS00020467 (cohort study). Registered on 15 January 2020, http://www.drks.de.

Serial changes in two immune checkpoint receptors and ligands, Tim-3/Gal-9 and PD-1/PD-L1 in peripheral blood prior to miscarriage: Comparison with pregnancies resulting in a live birth.

Immune checkpoints Tim-3/Gal-9 and PD-1/PL-1 are involved in the maintenance of maternal-fetal immune tolerance systematically and locally. This study aimed to compare the serial changes of Tim-3/Gal-9, and PD-1/PL-1 in peripheral blood over a 4-week period after blastocyst transfer, between women who had a live birth and those who miscarried. Serial blood samples were obtained on the day of ET, and 9, 16, 23, and 30 days after ET for the measurement of Tim-3 and PD-1 expressions on various lymphocytes by flow cytometry. Concentrations of serum Gal-9 and PD-L1 were measured by ELISA. In pregnancies that resulted in a live birth, a significant and sustained increase in the proportion of Tim-3+ pNK cells was observed from the 9th to 30th days after ET, whilst the concentration of serum PD-L1 was significantly increased on the 23rd and 30th days after ET when compared to the day of ET. In pregnancies that later miscarried, none of the parameters were significantly changed across all the time points examined. When comparing the results between the two groups, the proportion of Tim-3+ CD56dim NK cells in the women who had a live birth was significantly higher than that in women who miscarried from the 9th to 30th day after ET. A significant and sustained increase in the proportion of Tim-3+ pNK cells was observed in pregnancies resulting in a live birth but not in pregnancies resulting in a miscarriage, suggesting the changes may be associated with successful pregnancy outcomes.

Changes in genotoxic stress response, ribogenesis and PAP (3'-phosphoadenosine 5'-phosphate) levels are associated with loss of desiccation tolerance in overprimed Medicago truncatula seeds.

Re‐establishment of desiccation tolerance is essential for the survival of germinated seeds facing water deficit in the soil. The molecular and ultrastructural features of desiccation tolerance maintenance and loss within the nuclear compartment are not fully resolved. In the present study, the impact of desiccation‐induced genotoxic stress on nucleolar ultrastructure and ribogenesis was explored along the rehydration−dehydration cycle applied in standard seed vigorization protocols. Primed and overprimed Medicago truncatula seeds, obtained through hydropriming followed by desiccation (dry‐back), were analysed. In contrast to desiccation‐tolerant primed seeds, overprimed seeds enter irreversible germination and do not survive dry‐back. Reactive oxygen species, DNA damage and expression profiles of antioxidant/DNA Damage Response genes were measured, as main hallmarks of the seed response to desiccation stress. Nuclear ultrastructural features were also investigated. Overprimed seeds subjected to dry‐back revealed altered rRNA accumulation profiles and up‐regulation of genes involved in ribogenesis control. The signal molecule PAP (3′‐phosphoadenosine 5′‐phosphate) accumulated during dry‐back only in primed seeds, as a distinctive feature of desiccation tolerance. The presented results show the molecular and ultrastructural landscapes of the seed desiccation response, including substantial changes in nuclear organization.

Cluster analysis of splenocyte microRNAs in the pig reveals key signal regulators of immunomodulation in the host during acute and chronic Toxoplasma gondii infection

BackgroundToxoplasma gondii is an obligate intracellular protozoan parasite that can cause a geographically widespread zoonosis. Our previous splenocyte microRNA profile analyses of pig infected with T. gondii revealed that the coordination of a large number of miRNAs regulates the host immune response during infection. However, the functions of other miRNAs involved in the immune regulation during T. gondii infection are not yet known.MethodsClustering analysis was performed by K-means, self-organizing map (SOM), and hierarchical clustering to obtain miRNA groups with the similar expression patterns. Then, the target genes of the miRNA group in each subcluster were further analyzed for functional enrichment by Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway to recognize the key signaling molecules and the regulatory signatures of the innate and adaptive immune responses of the host during T. gondii infection.ResultsA total of 252 miRNAs were successfully divided into 22 subclusters by K-means clustering (designated as K1–K22), 29 subclusters by SOM clustering (designated as SOM1–SOM29), and six subclusters by hierarchical clustering (designated as H1–H6) based on their dynamic expression levels in the different infection stages. A total of 634, 660, and 477 GO terms, 15, 26, and 14 KEGG pathways, and 16, 15, and 7 Reactome pathways were significantly enriched by K-means, SOM, and hierarchical clustering, respectively. Of note, up to 22 miRNAs mainly showing downregulated expression at 50 days post-infection (dpi) were grouped into one subcluster (namely subcluster H3-K17-SOM1) through the three algorithms. Functional analysis revealed that a large group of immunomodulatory signaling molecules were controlled by the different miRNA groups to regulate multiple immune processes, for instance, IL-1-mediated cellular response and Th1/Th2 cell differentiation partly depending on Notch signaling transduction for subclusters K1 and K2, innate immune response involved in neutrophil degranulation and TLR4 cascade signaling for subcluster K15, B cell activation for subclusters SOM17, SOM1, and SOM25, leukocyte migration, and chemokine activity for subcluster SOM9, cytokine–cytokine receptor interaction for subcluster H2, and interleukin production, chemotaxis of immune cells, chemokine signaling pathway, and C-type lectin receptor signaling pathway for subcluster H3-K17-SOM1.ConclusionsCluster analysis of splenocyte microRNAs in the pig revealed key regulatory properties of subcluster miRNA molecules and important features in the immune regulation induced by acute and chronic T. gondii infection. These results contribute new insight into the identification of physiological immune responses and maintenance of tolerance in pig spleen tissues during T. gondii infection.Graphical

Establishment of Chimerism and Organ Transplant Tolerance in Laboratory Animals: Safety and Efficacy of Adaptation to Humans.

The definition of immune tolerance to allogeneic tissue and organ transplants in laboratory animals and humans continues to be the acceptance of the donor graft, rejection of third-party grafts, and specific unresponsiveness of recipient immune cells to the donor alloantigens in the absence of immunosuppressive treatments. Actively acquired tolerance was achieved in mice more than 60 years ago by the establishment of mixed chimerism in neonatal mice. Once established, mixed chimerism was self-perpetuating and allowed for acceptance of tissue transplants in adults. Successful establishment of tolerance in humans has now been reported in several clinical trials based on the development of chimerism after combined transplantation of hematopoietic cells and an organ from the same donor. This review examines the mechanisms of organ graft acceptance after establishment of mixed chimerism (allo-tolerance) or complete chimerism (self-tolerance), and compares the development of graft versus host disease (GVHD) and graft versus tumor (GVT) activity in complete and mixed chimerism. GVHD, GVT activity, and complete chimerism are also discussed in the context of bone marrow transplantation to treat hematologic malignancies. The roles of transient versus persistent mixed chimerism in the induction and maintenance of tolerance and organ graft acceptance in animal models and clinical studies are compared. Key differences in the stability of mixed chimeras and tolerance induction in MHC matched and mismatched rodents, large laboratory animals, and humans are examined to provide insights into the safety and efficacy of translation of results of animal models to clinical trials.

Transcriptome Analysis Revealed a Positive Role of Ethephon on Chlorophyll Metabolism of Zoysia japonica under Cold Stress.

Zoysia japonica is a warm-season turfgrass with a good tolerance and minimal maintenance requirements. However, its use in Northern China is limited due to massive chlorophyll loss in early fall, which is the main factor affecting its distribution and utilization. Although ethephon treatment at specific concentrations has reportedly improved stress tolerance and extended the green period in turfgrass, the potential mechanisms underlying this effect are not clear. In this study, we evaluated and analyzed chlorophyll changes in the physiology and transcriptome of Z. japonica plants in response to cold stress (4 °C) with and without ethephon pretreatment. Based on the transcriptome and chlorophyll content analysis, ethephon pretreatment increased the leaf chlorophyll content under cold stress by affecting two processes: the stimulation of chlorophyll synthesis by upregulating ZjMgCH2 and ZjMgCH3 expression; and the suppression of chlorophyll degradation by downregulating ZjPAO, ZjRCCR, and ZjSGR expression. Furthermore, ethephon pretreatment increased the ratio of chlorophyll a to chlorophyll b in the leaves under cold stress, most likely by suppressing the conversion of chlorophyll a to chlorophyll b due to decreased chlorophyll b synthesis via downregulation of ZjCAO. Additionally, the inhibition of chlorophyll b synthesis may result in energy redistribution between photosystem II and photosystem I.

IL-10+ regulatory B cells are dysregulated in patients with seasonal and perennial allergy

B regulatory cells (Breg) have been shown to have the capacity to produce IL-10 and play a role in immune tolerance. We hypothesize that IL-35 supports the maintenance of immune tolerance by inducing IL-10+ Bregs. We further hypothesized that IL-10+ Bregs are dysregulated in individuals with seasonal and perennial allergy.

Targeting regulatory T cells in anti-PD-1/PD-L1 cancer immunotherapy.

The programmed death (PD)-1/PD-ligand (PD-L) pathway and regulatory T cells (Tregs) are essential for the maintenance of immune tolerance. Their activation in the tumour microenvironment contributes to the evasion of the transformed cells from the immune surveillance and the suppression of an antitumour immune response. Therefore, PD-1/PD-L1 and Tregs are important targets for cancer immunotherapy. Our review focuses on the current role of the PD-1/PD-L1 axis in Treg development and function in the tumour microenvironment. We also discuss combination therapy with PD-1/PD-L1 inhibitors and Treg-modulating agents affecting the adenosinergic pathway, TGF-β signalling, immune checkpoints and other approaches to downregulation of Tregs.

Synaptic transmission molecules and their role in the pathogenesis of allergic rhinitis

Immune cells and molecules, as well as synaptic transmission molecules play a regulatory role in the communication pathways of the entire body when it is necessary to engage all body resources in the fight against infections or tumor cells wherever they appear. In potential allergy, the neuroimmune network controls allergen tolerance maintenance at both local and systemic levels.The review focuses on different neurotransmitters and our understanding of a balance and imbalance between the immune system and the nervous system in allergic inflammation, including allergic rhinitis. However, the pathogenesis of the two endotypes of rhinitis (conventional allergic rhinitis and local allergic rhinitis) and the impact of the neuroimmune network on it remain unresolved.

Trophoblast-derived Lactic Acid Orchestrates Decidual Macrophage Differentiation via SRC/LDHA Signaling in Early Pregnancy.

Lactic acid (LA) metabolism in the tumor microenvironment contributes to the establishment and maintenance of immune tolerance. This pathway is characterized in tumor associated macrophages. However, the role and pathway of LA metabolism at maternal-fetal interface during early pregnancy, especially in decidual macrophage differentiation, are still unclear. Herein, for the first time, we discovered that LA can trigger either M2 or M1 macrophage polarization via oxidative phosphorylation and glycolysis regulation under normoxia or hypoxia, respectively. Also, LA metabolism played a vital role in decidual macrophages-mediated recurrent pregnancy loss (RPL), through HIF-1α/SRC/LDHA pathway. Moreover, blockade of LA intake with AZD3965 (MCT-1 inhibitor) could rescue pregnancy in an abortion-prone mouse model, suggesting a potential therapeutic target in RPL. Collectively, the present study identifies the previously unknown functions of LA metabolism in the differentiation of decidual macrophages in early normal pregnancy and RPL, and provides a potential therapeutic strategy in RPL by manipulating decidual macrophages' functions through LA metabolic pathway.

Abstract PR04: CRISPR-mediated PTPN2 deletion in CAR T cells enhances anti-tumor efficacy

Abstract Chimeric Antigen Receptor T cell (CAR T) immunotherapy has been remarkably successful in the treatment of B-Cell Acute Lymphoblastic Leukemia (B-ALL). However, beyond hematological malignancies, CAR T cells have been ineffective in treating solid tumors. Novel approaches for enhancing the ability of CAR T cells to combat solid tumors are urgently required. Protein tyrosine phosphatases (PTPs) are enzymes that regulate a wide range of physiological processes including metabolism, cellular growth, proliferation and differentiation by controlling tyrosine phosphorylation-dependent signaling. PTPs are key regulators of T cell signaling and contribute to the maintenance of immune tolerance. Studies from our group have shown that PTPN2 plays pivotal role in negatively regulating T cell receptor (TCR) signaling by dephosphorylating and inactivating the Src family protein tyrosine kinase LCK (Wiede, Shields et al. 2011). PTPN2 also attenuates cytokine signaling by dephosphorylating JAK-1, JAK-3 and their target substrates STAT-1, -3 and -5 in a cell context-dependent manner (Simoncic, Lee-Loy et al. 2002, ten Hoeve, de Jesus Ibarra-Sanchez et al. 2002, Wiede, Shields et al. 2011, Wiede, La Gruta et al. 2014). Since CARs signal via LCK, and cytokine signaling is critical for CAR T cell function, we postulated that inhibiting PTPN2 might bolster the anti-tumor activity of CAR T cells. Here we used CRISPR-Cas9-ribonucleoprotein (RNP)-mediated genome editing to delete PTPN2 in CAR T cells. Using this approach PTPN2 was efficiently deleted in CAR T cells and the deletion of PTPN2 significantly enhanced the anti-tumor efficacy of CAR T cells in vitro and in vivo. This abstract is also being presented as Poster P004. Citation Format: Xin Du, Florian Wiede, Phillip K. Darcy, Tony Tiganis. CRISPR-mediated PTPN2 deletion in CAR T cells enhances anti-tumor efficacy [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2021 Oct 5-6. Philadelphia (PA): AACR; Cancer Immunol Res 2022;10(1 Suppl):Abstract nr PR04.

ShareOn: Shared Resource Dynamic Container Migration Framework for Real-Time Support in Mobile Edge Clouds

Mobile Edge Cloud (MEC) technology is envisioned to play a key role in next generation mobile networks by supporting low-latency applications using geographically distributed local cloud clusters. However, MEC faces challenges of resource assignment and load balancing to support user mobility and latency-sensitive applications. Virtualized resource reallocation techniques including dynamic service migration are evolving to achieve load balance, fault tolerance and system maintenance objectives for resource constrained edge nodes. In this work, a compute and network-aware lightweight resource sharing framework with dynamic container migration, ShareOn, is proposed. The migration framework is validated using a set of heterogeneous edge cloud nodes distributed in San Francisco city, serving mobile taxicab users across that region. The end-to-end system is implemented using a container hypervisor called LXD (Linux Container Hypervisor) executing a real-time application to detect license number plates in automobiles. The system is evaluated based on key metrics associated with application quality-of-service (QoS) and network efficiency such as the average system response time and the migration cost for different combinations of load, compute resources, inter-edge cloud bandwidth, network and user latency. A detailed migration cost analysis enables evaluation of migration strategies to improve ShareOn’s performance in comparison to alternative migration techniques, achieving a gain of 15–22% in system response time for highly loaded edge cloud nodes.

Increased suppressor activity of transformed ex vivo regulatory T-cells in comparison with unstimulated cells of the same donor

Regulatory T-cells CD4⁺CD25⁺FoxP3⁺CD127low (Tregs) play a key role in the maintenance of tolerance to auto antigens, inhibit function of effector T and B lymphocytes, and provide a balance between effector and regulatory arms of immunity. Patients with autoimmune diseases have decreased Treg numbers and impaired suppressive activity. Transformed ex vivo autologous Tregs could restore destroyed balance of the immune system. We developed a method for Treg precursor cell cultivation. Following the method, we were able to grown up 300-400 million of Tregs cells from 50 ml of peripheral blood during a week. Transformed ex vivo Tregs are 90-95% CD4⁺CD25⁺FoxP3⁺CD127low and have increased expression of transcription genes FoxP3 and Helios. Transformed ex vivo Tregs have increased demethylation of FoxP3 promoter and activated genes of proliferation markers Cycline B1, Ki67 and LGALS 1. Transformed ex vivo Tregs have increased suppressive activity and up to 80-90% these cells secrete cytokines TNFα и IFNγ. Our data suggest transformed ex vivo autologous Tregs have genetic, immunophenotypic and functional characteristics for regulatory T-cells and further can be used for adoptive immunotherapy autoimmune diseases and inhibition of transplantation immunity.

Regulatory T cells in acute and chronic human Chikungunya infection

Chikungunya virus (CHIKV) infection generates strong immune responses that are associated with the disease pathophysiology. Regulatory T cells (Treg-cluster of differentiation (CD)-4+CD25highforkhead box P3 (FOXP3+)) are essential for the induction and maintenance of peripheral tolerance. Thus, they play key roles in determining the patient prognosis by preventing excessive immune responses via different suppression immune mechanisms. However, the regulatory mechanisms involved in human CHIKV infection are still poorly understood. Here, we characterize for the first time the Treg cell molecule-associated-mechanism during acute and chronic human Chikungunya disease. Here, we assessed the Treg cell population and molecule-associated mechanism in the peripheral blood samples of acute and chronic patients with Chikungunya. Our results indicate that CHIKV infection is associated with reduced frequency of Tregs, along with the impaired expression and production of Treg functional markers, including CD39, CD73, perforin, granzyme, programmed death 1 (PD-1), cytotoxic T lymphocyte antigen (CTLA)-4, and transforming growth factor (TGF)-β. This observation suggests that Treg cells possess the poor regulatory capacity in both acute and chronic phases of the disease. Taken together, these data provide significant evidence that the imbalanced response of Treg cells plays an essential role in establishing the pathogenesis of Chikungunya.

Membrane Transporters of the Major Facilitator Superfamily Are Essential for Long-Term Maintenance of Phenotypic Tolerance to Multiple Antibiotics in E. coli.

ABSTRACTAntibiotic tolerance is not only the key underlying the cause of recurrent and chronic bacterial infections but it is also a factor linked to exacerbation of diseases, such as tuberculosis, cystic fibrosis-associated lung infection, and candidiasis. This phenomenon was previously attributed to a switch to physiological dormancy in a bacterial subpopulation triggered by environmental signals. However, we recently showed that expression of phenotypic antibiotic tolerance during nutrient starvation is highly dependent on robust production of proteins that actively maintain the bacterial transmembrane proton motive force (PMF), even under a nutrient-deficient environment. To investigate why PMF needs to be maintained for expression of phenotypic antibiotic tolerance, we tested the relative functional role of known transporters and efflux pumps in tolerance development by assessing the effect of deletion of specific efflux pump and transporter-encoding genes on long-term maintenance of antibiotic tolerance in an Escherichia coli population under starvation. We identified eight specific efflux pumps and transporters and two known efflux pump components, namely, ChaA, EmrK, EmrY, SsuA, NhaA, GadC, YdjK, YphD, TolC, and ChaB, that play a key role in tolerance development and maintenance. In particular, deletion of each of the nhaA and chaB genes is sufficient to totally abolish the tolerance phenotypes during prolonged antimicrobial treatment. These findings therefore depict active, efflux-mediated bacterial tolerance mechanisms and facilitate design of intervention strategies to prevent and treat chronic and recurrent infections due to persistence of antibiotic-tolerant subpopulations in the human body.IMPORTANCE We recently showed that the antibiotic-tolerant subpopulation of bacteria or persisters actively maintain the transmembrane proton motive force (PMF) to survive starvation stress for a prolonged period. This work further shows that the reason why antibiotic persisters need to maintain PMF is that PMF is required to support a range of efflux or transportation functions. Intriguingly, we found that tolerance-maintaining efflux activities were mainly encoded by 10 efflux or transporter genes. Because our study showed that deletion of even one of these genes could cause a significant reduction in tolerance level, we conclude that the products of these genes play an essential role in enhancing the survival fitness of bacteria during starvation or under other adverse environmental conditions. These gene products are therefore excellent targets for future design of antimicrobial agents that eradicate antibiotic tolerant persisters and prevent occurrence of chronic and recurrent human infections.

Reliability Evaluation of Bicube-Based Multiprocessor System under the g-Good-Neighbor Restriction

Multiprocessor systems are commonly deployed for big data analysis because of evolution in technologies such as cloud computing, IoT, social network and so on. Reliability evaluation is of significant importance for maintenance and improvement of fault tolerance for multiprocessor systems, and system-level diagnosis is a primary strategy to identify the faulty processors in the systems. In this paper, we first determine the [Formula: see text]-good-neighbor connectivity of the [Formula: see text]-dimensional Bicube-based multiprocessor system [Formula: see text], a novel variant of hypercube. Besides, we establish the [Formula: see text]-good-neighbor diagnosability of the Bicube-based multiprocessor system [Formula: see text] under the PMC and MM* models.

Immunomodulation with Romiplostim in Young Adult Primary Immune Thrombocytopenia (ITP) As Second-Line Strategy (iROM-study)

Introduction: To date most treatment strategies of primary immune thrombocytopenia (ITP) are symptomatic, preventing premature platelet destruction and increasing their production. New strategies should focus on targeting the immune dysregulation, rather than the platelet count. Rituximab and dexamethasone have the potential to induce tolerogenic mechanisms, however with moderate long-term results (<30%). Thrombopoietin-receptor agonists (TPO-RAs) obviously have the potential to affect the course of the disease with up to 30% treatment-free remission. Possible mechanisms could be exposure to high-dose antigen and/or the innate immune activity of platelets, especially the release of TGF-ß, which may stimulate or restore regulatory T cells (Tregs). Tregs play a fundamental role in the maintenance of immune tolerance. Previous studies have shown lower and impaired function of Tregs in the peripheral blood of ITP patients.Methods: The iROM study is a national multi-center, open label, single arm pilot study that aims to explore possible immunomodulatory effects of romiplostim administered as second line drug in young adults with ITP. Patients who failed, did not tolerate or relapsed after first-line treatment with steroids and/or intravenous immunoglobulin (IVIG) were included, irrespective of disease duration. Romiplostim was administered subcutaneously for 22 weeks and then stopped. The dose was adjusted every week depending on platelet response, following the product information (target platelet count 50-200x10 9/l). Follow-up was performed until week 52. Immunologic investigations were done at weeks 1, 6, 12, 22 and 52. Tregs (CD4 +, CD25 +, CD127 low) were investigated by flow cytometry and reported as percentage Tregs/CD3. Because of comedication at week 1 (IVIG, steroids), week 6 was defined as the initial immunological state. Confirmatory tests were performed using a paired samples Wilcoxon test at a two-sided alpha of 5%. The p-values are adjusted using the Holm method for all secondary analyses.Results: Between 2016 and 2020, 15 patients were enrolled, including two dropouts. Of the 13 patients analyzed, 9 had newly diagnosed ITP (<3 months), median age 31 years (IQR 8), and 4 chronic ITP (>12 months), median age 31.5 years (IQR 8.75), with a median platelet count at enrollment of 26x10 9/l (IQR 41) and 49.5x10 9/l (IQR 88.5), and at week 52, 168x10 9/l (IQR 88) and 96x10 9/l (IQR 23.5), respectively. All patients were on ITP treatment at enrollment (steroids and/or IVIG). In 6 out of 9 patients with newly diagnosed ITP, discontinuation of romiplostim was successful with sustained treatment-free complete remission (TFR) at 1 year, whereas all patients with chronic ITP relapsed and restarted various treatments.Interestingly, romiplostim dose titration was lower and platelet count response higher and more stable in patients achieving TFR (Fig 1). Platelet counts in patients with relapse showed a very jagged curve over the 22 weeks of treatment. Tregs increased between weeks 6 and 22 (end of treatment), so as between weeks 6 and 52 (end of study) in the whole group of patients with a median change of 0.62 (CI95 (0.14, 1.26)) (p=0.017) at end of study. Tregs variation for patients with sustained TFR versus no remission is shown in Fig 2a, and for the 9 patients with newly diagnosed ITP in Fig 2b.Conclusion : These results support the assumption that early treatment of ITP with TPO-RAs, e.g. romiplostim, could positively influence the natural course of ITP. Induction of tolerance may be more successful in the early stage of an autoimmune disorder because of autoimmune expansion and epitope spreading. We also assume that induction of tolerance may be more successful in younger patients because of potentially reduced immunosenescence. In this small trial only 3 out of 9 patients (33%) with newly diagnosed ITP relapsed after stopping treatment according to the iROM protocol. In contrast, all 4 patients with chronic ITP relapsed after stopping treatment. Our observation of a higher increase of platelets and a more stable increase of Tregs in patients with sustained TFR in comparison to those with relapse corroborate the hypothesis that the tolerogenic stimulus may be supported by the platelet mass. Limitations of the study were the small sample size, the heterogeneity of the patient population regarding ITP duration, and preceding medications overlapping the first study weeks. [Display omitted] DisclosuresSchifferli: Sobi: Honoraria; Novartis: Honoraria, Research Funding. Rovo: Novartis: Research Funding; AG Alexion: Honoraria; BMS: Honoraria; OrPhaSwiss GmbH: Honoraria; Swedish Orphan Biovitrum AG: Honoraria; Amgen: Other: Financial support for congresses and conference travel; AstraZeneca: Other; BMS: Other; Sanofi: Other; Roche: Other; AstraZeneca: Honoraria; Novartis: Honoraria; CSL Behring: Research Funding; AG Alexion: Research Funding. Kuehne: Novartis: Research Funding; UCB: Honoraria; SOBI: Honoraria; Amgen: Research Funding.