Regulatory Cell Responses Research Articles

ScImmOmics: a manually curated resource of single-cell multi-omics immune data.

Single-cell sequencing technology has enabled the discovery and characterization of subpopulations of immune cells with unique functions, which is critical for revealing immune responses under healthy or disease conditions. Efforts have been made to collect and curate single-cell RNA sequencing (scRNA-seq) data, yet an immune-specific single-cell multi-omics atlas with harmonized metadata is still lacking. Here, we present scImmOmics (https://bio.liclab.net/scImmOmics/home), a manually curated single-cell multi-omics immune database constructed based on high-quality immune cells with known immune cell labels. Currently, scImmOmics documents >2.9 million cell-type labeled immune cells derived from seven single-cell sequencing technologies, involving 131 immune cell types, 47 tissues and 4 species. To ensure data consistency, we standardized the nomenclature of immune cell types and presented them in a hierarchical tree structure to clearly describe the lineage relationships within the immune system. scImmOmics also provides comprehensive immune regulatory information, including T-cell/B-cell receptor sequencing clonotype information, cell-specific regulatory information (e.g. gene/chromatin accessibility/protein/transcription factor states within known cell types, cell-to-cell communication and co-expression networks) and immune cell responses to cytokines. Collectively, scImmOmics is a comprehensive and valuable platform for unraveling the heterogeneity and diversity of immune cells and elucidating the specific regulatory mechanisms at the single-cell level.

Autoimmune and Neoplastic Outcomes After the mRNA Vaccination: The Role of T Regulatory Cell Responses

A plethora of autoimmune disease incidences occured after COVID-19 mRNA injections were rolled out. Aggressive cancer cases have occurred in the bodies of recipients at sites where the mRNA was injected and at distant metastatic sites. The mRNA vaccines cause thymic involution (shrinking) and dysregulation of the T regulatory (Treg) and T effector (Teff) homeostatic cell balance. Activated immune cells deliver spike protein to the thymic epithelial cells, damaging them. The Treg/Teff balance may determine the fate of autoimmunity and/or cancer and is different for patients with cancer versus those without any cancerous tissues. Repeated mRNA injections lead to empirical evidence of impaired immune functions (elevated IgG4, PD-L1), associated with increased autoimmunity and cancer risks, and decreased resistance to infections. In the with-cancer recipients, the mRNA vaccine may be associated with either autoimmunity or further progression of the cancer(s) depending on the immunotherapy treatment the patient receives. When an antigen stimulates the immune system, specific T regulatory (Treg) and T effector (Teff) subpopulations develop from naïve T cells. An imbalance between Treg and Teff cells can lead to either cancer or autoimmunity. Treg cells are beneficial in that they protect from autoimmunity. However, they suppress the immune response to tumors. In this review, we analyze Treg responses after SARS-CoV-2 mRNA vaccination and find distinct pathological responses under differing conditions. Injection with modified mRNA can lead to a delayed but highly active immune response, resulting in overactivation of the inflammasome. The mRNA “vaccine” induces a very strong IgG antibody response, while suppressing CD8+ T cell activation. Exosomes distribute the recombinant, synthetic spike protein and the mRNA encoding it throughout the organism. In cancer patients, disease progression depends on the starting point of the cancer patient at the time of injection and the type of cancer treatment underway. Migration of circulating dendritic cells and Treg cells back to the thymus, while they are carrying spike protein, damages the medullary thymic epithelial cells and accelerates thymic involution, a direct cause of inflammaging and immunosenescence. In summary, the Treg responses to mRNA injections and subsequent mRNA-encoded SARS-CoV-2 spike protein expression may disrupt immune capacities resulting in accelerated development of autoimmune disease and cancer. The processes discussed here are consistent with both epidemiological findings and case reports.

N-Glycan Branching Regulates BTLA Opposite to PD-1 to Limit T Cell Hyperactivity Induced by Branching Deficiency.

N-glycan branching is a potent and multifaceted negative regulator of proinflammatory T cell and B cell function. By promoting multivalent galectin-glycoprotein lattice formation at the cell surface, branching regulates clustering and/or endocytosis of the TCR complex (TCR+CD4/CD8), CD45, CD25, BCR, TLR2 and TLR4 to inhibit T cell and B cell activation/proliferation and proinflammatory TH1 and TH17 over TH2 and induced T regulatory cell responses. In addition, branching promotes cell surface retention of the growth inhibitory receptor CTLA-4. However, the role of N-glycan branching in regulating cell surface levels of other checkpoint receptors such as BTLA (B and T lymphocyte attenuator) and PD-1 (programmed cell death protein 1) is unknown. In this study, we report that whereas branching significantly enhances PD-1 cell surface expression by reducing loss from endocytosis, the opposite occurs with BTLA in both T cells and B cells. T cell hyperactivity induced by branching deficiency was opposed by BTLA ligation proportional to increased BTLA expression. Other members of the BTLA/HVEM (herpesvirus entry mediator) signaling axis in T cells, including HVEM, LIGHT, and CD160, are largely unaltered by branching. Thus, branching-mediated endocytosis of BTLA is opposite of branching-induced inhibition of PD-1 endocytosis. In this manner, branching deficiency-induced upregulation of BTLA appears to serve as a checkpoint to limit extreme T cell hyperactivity and proinflammatory outcomes in T cells with low branching.

Cardiac tissue-resident vesicles differentially modulate anti-fibrotic phenotype by age and sex through synergistic miRNA effects

Aging is a risk factor for cardiovascular disease, the leading cause of death worldwide. Cardiac fibrosis is a harmful result of repeated myocardial infarction that increases risk of morbidity and future injury. Interestingly, both rates and outcomes of cardiac fibrosis differ between young and aged individuals, as well as men and women. Here, for the first time, we identify and isolate matrix-bound extracellular vesicles from the left ventricles (LVs) of young or aged males and females in both human and murine models. These LV vesicles (LVVs) show differences in morphology and content between these four cohorts in both humans and mice. LVV effects on fibrosis were also investigated in vitro, and aged male LVVs were pro-fibrotic while other LVVs were anti-fibrotic. From these LVVs, we could identify therapeutic miRNAs to promote anti-fibrotic effects. Four miRNAs were identified and together, but not individually, demonstrated significant cardioprotective effects when transfected. This suggests that miRNA synergy can regulate cell response, not just individual miRNAs, and also indicates that biological agent-associated therapeutic effects may be recapitulated using non-immunologically active agents. Furthermore, that chronic changes in LVV miRNA content may be a major factor in sex- and age-dependent differences in clinical outcomes of cardiac fibrosis.

Estrogen-Related Receptor α: A Key Transcription Factor in the Regulation of Energy Metabolism at an Organismic Level and a Target of the ABA/LANCL Hormone Receptor System.

The orphan nuclear receptor ERRα is the most extensively researched member of the estrogen-related receptor family and holds a pivotal role in various functions associated with energy metabolism, especially in tissues characterized by high energy requirements, such as the heart, skeletal muscle, adipose tissue, kidney, and brain. Abscisic acid (ABA), traditionally acknowledged as a plant stress hormone, is detected and actively functions in organisms beyond the land plant kingdom, encompassing cyanobacteria, fungi, algae, protozoan parasites, lower Metazoa, and mammals. Its ancient, cross-kingdom role enables ABA and its signaling pathway to regulate cell responses to environmental stimuli in various organisms, such as marine sponges, higher plants, and humans. Recent advancements in understanding the physiological function of ABA and its mammalian receptors in governing energy metabolism and mitochondrial function in myocytes, adipocytes, and neuronal cells suggest potential therapeutic applications for ABA in pre-diabetes, diabetes, and cardio-/neuroprotection. The ABA/LANCL1-2 hormone/receptor system emerges as a novel regulator of ERRα expression levels and transcriptional activity, mediated through the AMPK/SIRT1/PGC-1α axis. There exists a reciprocal feed-forward transcriptional relationship between the LANCL proteins and transcriptional coactivators ERRα/PGC-1α, which may be leveraged using natural or synthetic LANCL agonists to enhance mitochondrial function across various clinical contexts.

Effect of the community size and spatial arrangement of cardiomyocyte network in regulating cell response to a proarrhythmic compound

Effect of the community size and spatial arrangement of cardiomyocyte network in regulating cell response to a proarrhythmic compound

Mycoparasitism related targets of Tmk1 indicate stimulating regulatory functions of this MAP kinase in Trichoderma atroviride

Mycoparasitism is a key feature of Trichoderma (Hypocreales, Ascomycota) biocontrol agents. Recent studies of intracellular signal transduction pathways of the potent mycoparasite Trichoderma atroviride revealed the involvement of Tmk1, a mitogen-activated protein kinase (MAPK), in triggering the mycoparasitic response. We previously showed that mutants missing Tmk1 exhibit reduced mycoparasitic activity against several plant pathogenic fungi. In this study, we identified the most robustly regulated targets that were governed by Tmk1 during mycoparasitism using transcriptome and proteome profiling. Tmk1 mainly exerts a stimulating function for T. atroviride during its mycoparasitic interaction with the fungal plant pathogen Rhizoctonia solani, as reflected by 89% of strongly differently responding genes in the ∆tmk1 mutant compared to the wild type. Specifically, 54% of these genes showed strong downregulation in the response with a deletion of the tmk1 gene, whereas in the wild type the same genes were strongly upregulated during the interaction with the fungal host. These included the gene encoding the mycoparasitism-related proteinase Prb1; genes involved in signal transduction pathways such as a candidate coding for a conserved 14-3-3 protein, and a gene coding for Tmk2, the T. atroviride cell-wall integrity MAP kinase; genes encoding a specific siderophore synthetase, and multiple FAD-dependent oxidoreductases and aminotransferases. Due to the phosphorylating activity of Tmk1, different (phospho-)proteomics approaches were applied and identified proteins associated with cellular metabolism, energy production, protein synthesis and fate, and cell organization. Members of FAD- and NAD/NADP-binding-domain proteins, vesicular trafficking of molecules between cellular organelles, fungal translational, as well as protein folding apparatus were among others found to be phosphorylated by Tmk1 during mycoparasitism. Outstanding downregulation in the response of the ∆tmk1 mutant to the fungal host compared to the wild type at both the transcriptome and the proteome levels was observed for nitrilase, indicating that its defense and detoxification functions might be greatly dependent on Tmk1 during T. atroviride mycoparasitism. An intersection network analysis between the identified transcripts and proteins revealed a strong involvement of Tmk1 in molecular functions with GTPase and oxidoreductase activity. These data suggest that during T. atroviride mycoparasitism this MAPK mainly governs processes regulating cell responses to extracellular signals and those involved in reactive oxygen stress.

Materials‐Mediated In Situ Physical Cues for Bone Regeneration

AbstractPhysical cues like morphology, light, electric signal, mechanic signal, magnetic signal, and heat can be used as alternative regulators for expensive but short‐acting growth factors in bone tissue engineering to promote osteogenic differentiation and bone regeneration. As physical stimulation applied directly to the tissue cannot be focused on the bone defect area to regulate the cell behaviors and fate in situ, this limits the efficiency of precise bone regeneration. Biomaterials‐mediated in situ physical cues, as an effective strategy combining the synergistic effect of materials themselves, are put forward and studied widely to promote osteogenic differentiation and bone repair efficiently and precisely. Different types of physical cues provide different choices to better satisfy the requirements for targeted bone defect repair. In this review, the recent research about different biomaterials‐mediated physical cues accelerating osteogenesis in vitro and promoting in situ bone formation in vivo is introduced. Meanwhile, the corresponding possible mechanisms of various physical cues regulating cell responses are also discussed. This review provides useful and enlightening guidance for the utilization of intrinsically physical properties of functional materials to achieve efficient bone regeneration, leading to the design and construction of smart biomaterials for practical applications, and eventually promoting clinical translation.

Functions and mechanisms of the GPCR adaptor protein Norbin.

Norbin (Neurochondrin, NCDN) is a highly conserved 79 kDa adaptor protein that was first identified more than a quarter of a century ago as a gene up-regulated in rat hippocampus upon induction of long-term potentiation. Most research has focussed on the role of Norbin in the nervous system, where the protein is highly expressed. Norbin regulates neuronal morphology and synaptic plasticity, and is essential for normal brain development and homeostasis. Dysregulation of Norbin is linked to a variety of neurological conditions. Recently, Norbin was shown to be expressed in myeloid cells as well as neurons. Myeloid-cell specific deletion revealed an important role of Norbin as a suppressor of neutrophil-derived innate immunity. Norbin limits the ability of neutrophils to clear bacterial infections by curbing the responsiveness of these cells to inflammatory and infectious stimuli. Mechanistically, Norbin regulates cell responses through binding to its interactors, in particular to a wide range of G protein-coupled receptors (GPCRs). Norbin association with GPCRs controls GPCR trafficking and signalling. Other important Norbin interactors are the Rac guanine-nucleotide exchange factor P-Rex1 and protein kinase A. Downstream signalling pathways regulated by Norbin include ERK, Ca2+ and the small GTPase Rac. Here, we review the current understanding of Norbin structure, expression and its roles in health and disease. We also explore Norbin signalling through its interactors, with a particular focus on GPCR trafficking and signalling. Finally, we discuss avenues that could be pursued in the future to increase our understanding of Norbin biology.

Plasmodium vivax infection changes the peripheral immunoregulatory network: CD4 T follicular cells and B cells.

Regulatory and effector cell responses to Plasmodium vivax, the most common human malaria parasite outside Africa, remain understudied in naturally infected populations. Here we describe peripheral CD4+ T and B cell populations during and shortly after an uncomplicated P. vivax infection in 38 continuously exposed adult Amazonians. Consistent with previous observations, we found an increased frequency in CD4+ CD45RA- CD25+ FoxP3+ T regulatory cells that express the inhibitory molecule CTLA-4 during the acute infection, with a sustained expansion of CD21- CD27- atypical memory cells within the CD19+ B-cell compartment. Both Th1- and Th2-type subsets of CXCR5+ ICOShi PD-1+ circulating T follicular helper (cTfh) cells, which are thought to contribute to antibody production, were induced during P. vivax infection, with a positive correlation between overall cTfh cell frequency and IgG antibody titers to the P. vivax blood-stage antigen MSP119 . We identified significant changes in cell populations that had not been described in human malaria, such as an increased frequency of CTLA-4+ T follicular regulatory cells that antagonize Tfh cells, and a decreased frequency of circulating CD24hi CD27+ B regulatory cells in response to acute infection. In conclusion, we disclose a complex immunoregulatory network that is critical to understand how naturally acquired immunity develops in P. vivax malaria. This article is protected by copyright. All rights reserved.

Abstract 2409: A synergistic effect of miR-21-5p inhibitor and PARP1 inhibitor to enhance the radiosensitivity of oral squamous cell carcinoma

Abstract Radiotherapy is one of the standard treatments for oral squamous cell carcinoma (OSCC). Radiotherapy damages cancer cells mainly by inducing DNA double-strand breaks, but some advanced OSCC can effectively repair DNA damages, resulting in radiotherapy resistance. TCGA data showed that miR-21-5p was highly expressed in advanced OSCC and correlated with prognosis. However, the involvement of miR-21-5p in OSCC’s response to radiotherapy and the underlying mechanism are still unclear. When treated with a miR-21-5p inhibitor, we found OSCC cell lines (SAS and CAL33) became more sensitive to X-ray radiation at 2Gy (the commonly used single-dose in conventional radiotherapy), which was supported by the evidence that more resident 53BP1-marked-foci for non-repaired DNA double strand breaks (1.61±0.54 folder more in SAS, 1.47±0.49 folder more in CAL33, n=4, p<0.05) and less colony-forming capacity (14.62±2.36% in SAS, 18.65±4.32% in CAL33, n=3, p<0.05) than untreated control cells were observed at 24hr after radiation. However, the expression of PARP1, a DNA damage sensor for recognizing DNA damage and facilitating DNA repair, was significantly increased (1.38±0.12, n=4, p<0.05) in SAS cells treated with miR-21-5p inhibitor. In order to achieve a better tumor control, we tested the combined treatments with miR-21-5p inhibitor and PARP1 inhibitor (Olaparib) on SAS cells, which resulted in a synergistic effect in inhibition of the repair of DNA double strand breaks. The residual 53BP1 foci after 2Gy X-ray irradiation was increased 1.45±0.06 folder more when inhibiting both miR-21-5p and PARP1, while the colony-forming capacity of irradiated SAS cells was decreased by 39.55±5.89% (p<0.0001) in the same conditions. This work provided novel insights on the molecular mechanism of miR-21-5p regulated cell response to radiotherapy, which may give rise to potential therapeutic strategy for treatment of advanced OSCC. Citation Format: Lin Ma, Weitao Hu, Rui Fu, Anhui Wu, Qiangyong Deng, Qi Liu. A synergistic effect of miR-21-5p inhibitor and PARP1 inhibitor to enhance the radiosensitivity of oral squamous cell carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2409.

Phenotypic plasticity promotes lymph nodes metastasis and drug resistance in lung squamous cell carcinomas

BackgroundPhenotypic plasticity (PP) is a major promoter of tumor metastasis and drug resistance. Nevertheless, the molecular features and clinical significance of phenotypic plasticity in lung squamous cell carcinomas (LSCC) remained largely unexplored. MethodsPhenotypic plasticity-related genes (PPRG) and clinical information of LSCC were downloaded from the cancer genome atlas (TCGA). The expression profiles of PPRG were compared between patients with and without lymph node metastasis. The prognostic signature was constructed, and survival analysis was performed based on phenotypic plasticity. Immunotherapy responses, chemotherapeutic drugs and targeted drug responses were investigated. In addition, the results were verified in an external cohort. ResultsPatients with and without lymph node metastasis exhibited significantly different genomic characteristics of phenotypic plasticity. Enrichment analysis showed that PP was strongly associated with cell responses and cell contraction. Survival analysis demonstrated that PPRG could serve as independent prognostic factor for overall survival. The phenotypic plasticity-related signature successfully divided patients into high- and low-PP score groups. Patients with low-PP scores were more sensitive to PD-L1, Cisplatin, Gefitinib, Obatoclax. Mesylate, Paclitaxel, Sorafenib and Vinorelbine (all p < 0.05). While, patients with low-PP scores were more sensitive to Axitinib and Camptothecin (all p < 0.05). Consistent with the results from TCGA, the external cohort validated the above findings. ConclusionsOur study revealed that phenotypic plasticity may be involved in the lymph node metastasis in LSCC through regulating cell responses and cell contraction. Evaluation of phenotypic plasticity will assist clinicians in making treatment strategies.

316 A unique population of dermal conventional dendritic cells enhances TH2 and inhibits TH17 cell polarization in healthy skin

Dendritic cells (DC) play a crucial role in informing the adaptive immune system about infectious, innocuous or self antigens. Two developmentally distinct lineages of conventional DC, termed cDC1 and cDC2, have been described in mice and humans. cDC1 predominantly interact with CD8 T cells, while cDC2 interact with CD4 T cells to promote T helper (Th) and T regulatory cell responses. cDC2 present a high degree of phenotypic and functional heterogeneity in different tissues, suggesting that they adapt to diverse peripheral environments. Using high-dimensional proteomic and transcriptomic single-cell technologies, we could show that cDC2 exhibit unique signatures in different murine tissues at the steady state. Focusing on the developmental requirements of these subsets we could show that CD11blow cDC2, a population uniquely found in skin, required STAT6- and KLF4-dependent IL-13 signaling, while subsets in other tissues were STAT6-independent. IL-13 was not only necessary for the development of CD11blow cDC2, but also sufficient to rescue CD11blow cDC2 development in IL-13 KO mice and to differentiate CD11blow cDC2 in vitro. In naïve murine skin, dermal IL-13 was mostly derived from innate lymphoid cells expressing a resting ICOS+KLRG1-ST2- phenotype. In the absence of IL-13 signaling, dermal cDC2 were stable in number and continued to take up antigen but remained CD11bhi. They furthermore showed defective activation in response to different antigens and a diminished ability to support IL-4+ GATA3+ Th2 cell development, whereas anti-fungal IL-17+ RORyt+ responses were increased. Thus, our work identified that homeostatic IL-13 in healthy skin mediates a DC-driven protective non-inflammatory environment at the steady state, but might also contribute to its pro-allergic conditioning upon dysregulation.

Detection of pan-cancer surface protein biomarkers via a network-based approach on transcriptomics data.

Cell surface proteins have been used as diagnostic and prognostic markers in cancer research and as targets for the development of anticancer agents. Many of these proteins lie at the top of signaling cascades regulating cell responses and gene expression, therefore acting as 'signaling hubs'. It has been previously demonstrated that the integrated network analysis on transcriptomic data is able to infer cell surface protein activity in breast cancer. Such an approach has been implemented in a publicly available method called 'SURFACER'. SURFACER implements a network-based analysis of transcriptomic data focusing on the overall activity of curated surface proteins, with the final aim to identify those proteins driving major phenotypic changes at a network level, named surface signaling hubs. Here, we show the ability of SURFACER to discover relevant knowledge within and across cancer datasets. We also show how different cancers can be stratified in surface-activity-specific groups. Our strategy may identify cancer-wide markers to design targeted therapies and biomarker-based diagnostic approaches.

Recent advances in engineering nanotopographic substrates for cell studies.

Cells sense their environment through the cell membrane receptors. Interaction with extracellular ligands induces receptor clustering at the nanoscale, assembly of the signaling complexes in the cytosol and activation of downstream signaling pathways, regulating cell response. Nanoclusters of receptors can be further organized hierarchically in the cell membrane at the meso- and micro-levels to exert different biological functions. To study and guide cell response, cell culture substrates have been engineered with features that can interact with the cells at different scales, eliciting controlled cell responses. In particular, nanoscale features of 1–100 nm in size allow direct interaction between the material and single cell receptors and their nanoclusters. Since the first “contact guidance” experiments on parallel microstructures, many other studies followed with increasing feature resolution and biological complexity. Here we present an overview of the advances in the field summarizing the biological scenario, substrate fabrication techniques and applications, highlighting the most recent developments.

Aspartic Acid-Modified Phospholipids Regulate Cell Response and Rescue Memory Deficits in APP/PS1 Transgenic Mice.

Misfolding and accumulation of amyloid-β (Aβ) to form senile plaques are the main neuropathological signatures of Alzheimer's disease (AD). Decreasing Aβ production, inhibiting Aβ aggregation, and clearing Aβ plaques are thus considered an important strategy for AD treatment. However, numerous drugs cannot enter the AD clinical trials due to unsatisfactory biocompatibility, poor blood-brain barrier penetration, little biomarker impact, and/or low therapeutic indicators. Here, a pair of chiral aspartic acid-modified 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine (l- and d-Asp-DPPE) are prepared to build stabilized chiral liposomes. We find that both l- and d-liposomes are able to rescue Aβ aggregation-induced apoptosis, oxidative stress, and calcium homeostasis, in which the effect of d-liposomes is more obvious than that of l-ones. Furthermore, in AD model mice (APPswe/PS1d9 double-transgenic mice), chiral liposomes not only show biosafety but also strongly improve cognitive deficits and reduce Aβ deposition in the brain. Our results suggest that chiral liposomes, particularly, d-liposomes, could be a potential therapeutic approach for AD treatment. This study opens new horizons by showing that liposomes will be used for drug development in addition to delivery and targeting functions.

Probiotic Supplementation in Very Low Birthweight Infants: Effects on Systemic Immunity and Intestinal Inflammation

ObjectivesTo investigate serum immune/inflammatory profiles in preterm very low birthweight (BW) infants enrolled in a randomized trial of daily supplementation with a multi-strain probiotic. A central hypothesis is probiotics will promote T cell homeostasis via a T regulatory cell (Treg) response and suppress inflammatory Th1/Th17 cytokine profiles to promote intestinal microbiota diversity, reduce inflammation, and support barrier function.MethodsAfter parental informed consent, preterm infants admitted to a neonatal ICU are randomized into 2 groups (+/- probiotics; 30/group by NNT) stratified by BW. The probiotic group receives daily Tri-Blend (Abbott; B. lactis [BB-12], B. infantis [BB-02], S. thermophilis [H-4]; 0.5 g, 108 CFU/g) from early feeding to 34 weeks post-menstrual age. Data include: diagnoses, interventions, medications, feedings, growth trajectories, and length of stay; intestinal integrity protein biomarkers; fecal DNA analysis for intestinal microbiomics using amplicon-based 16S rRNA gene sequencing and shotgun metagenomics; and fecal metabolomics. This presentation focuses on results from bimonthly serum cytokine, chemokine, and growth factor profiles assayed using customized multiplex magnetic bead antibody panels (Luminex).ResultsLongitudinal serum immune/immunomodulatory profiles (up to 7 samples/subject) and clinical data are available for 17 subjects (as of 02/2022). We measured 18 inflammatory/immunomodulatory small proteins; all analytes varied within recognized ranges for human serum/plasma and, consequently, are interpretable for analysis of systemic pro-/anti-inflammatory polarization and for products released by circulating T cell and macrophage subsets. Data indicate chronic heightened inflammation in these preterm infants and evolving profiles of Th1, Th2, Th17, and Treg-dependent cytokines/chemokines.ConclusionsThis is the first study that comprehensively profiles circulating immune system/inflammatory biomarkers in young infants. We demonstrate novel findings on multiple, longitudinally sampled biomarkers and characterize chronic inflammation in this population. Small subject numbers to date preclude conclusions on immunomodulatory effects of probiotics.Funding SourcesAbbott Nutrition, Tano Research Fund, Georgetown University Medical Center.

Astragaloside IV ameliorates pulmonary vascular remodeling in hypoxia-induced pulmonary hypertension by restraining the T follicular helper cell response and expanding T follicular regulatory cell response

BackgroundPulmonary hypertension (PH) is a progressive disorder lacking a validated and effective therapy which characterized by elevated pulmonary arterial pressure, vascular remodeling and eventual death. FDA approved sildenafil is being used as a first-line drug for PH, however, neither survival rates nor quality of life have been improved because of side effects and patient noncompliance. Thus, the exploration of novel therapeutic drugs is urgently needed. Astragaloside IV (ASIV) exhibits a protective effect on HPH, but its mechanisms of action is unclear. HypothesisCD4+T cell subsets, Tfh and Tfr cells, may contribute to the development of chronic hypoxia-induced PH (HPH). We hypothesized that ASIV could effectively ameliorates pulmonary vascular remodeling of HPH by restraining the Tfh cell response and expanding Tfr cell response. Methods and resultsHPH mice model was established by exposure to chronic hypoxia for 21 days. Mice were randomly assigned to six groups: NaCl group, model group, SN group (100 mg/kg of sildenafil), low-dose group (20 mg/kg of ASIV), medium-dose group (40 mg/kg of ASIV) and high-dose group (80 mg/kg of ASIV). Primary culture and identification of distal pulmonary artery smooth muscle cells (PASMCs) in mice were established. Here, we demonstrated that ASIV treatment could significantly ameliorate the increase of mean PAP, RV/ (LV+S) ratio and PAMT in HPH mice. ASIV inhibited Tfh cell differentiation and IL-21 production, but promoted Tfr cell differentiation and TGF-β, IL-10 production. Chronic hypoxia promoted germinal center B cell responses, which inhibited by ASIV. ASIV regulated Tfh and Tfr cell differentiation by inhibiting the phosphorylation of mTOR signaling pathway, and the effect of ASIV-H was better than that observed in the SN group. ASIV inhibited the proliferation, migration and adhesion of PASMCs in vitro. Moreover, ASIV significantly downregulated the protein level of RhoA and upregulated the protein level of p27 in PASMCs under hypoxic condition. ConclusionCollectively, ASIV may regulate Tfh and Tfr cell responses to subsequently repress pulmonary vascular remodeling and hypoxic pulmonary hypertension.

Dissociation Pathways of the p53 DNA Binding Domain from DNA and Critical Roles of Key Residues Elucidated by dPaCS-MD/MSM.

p53 is a transcriptional factor that regulates cell response to a variety of stresses. About a half of all human tumors contain p53 mutations, and the accumulation of mutations in the DNA binding domain of p53 (p53-DBD) can cause destabilization of p53 and its complex with DNA. To identify the key residues of the p53-DBD/DNA binding and to understand the dissociation mechanisms of the p53-DBD/DNA complex, the dissociation process of p53-DBD from a DNA duplex that contains the consensus sequence (the specific target of p53-DBD) was investigated by a combination of dissociation parallel cascade selection molecular dynamics (dPaCS-MD) and the Markov state model (MSM). This combination (dPaCS-MD/MSM) enabled us to simulate dissociation of the two large molecules based on an all-atom model with a short simulation time (11.2 ± 2.2 ns per trial) and to analyze dissociation pathways, free energy landscape (FEL), and binding free energy. Among 75 trials of dPaCS-MD, p53-DBD dissociated first from the major groove and then detached from the minor groove in 93% of the cases, while 7% of the cases unbinding from the minor groove occurred first. Minor groove binding is mainly stabilized by R248, identified as the most important residue that tightly binds deep inside the minor groove. The standard binding free energy calculated from the FEL was -10.9 ± 0.4 kcal/mol, which agrees with an experimental value of -11.1 kcal/mol. These results indicate that the dPaCS-MD/MSM combination can be a powerful tool to investigate dissociation mechanisms of two large molecules. Analysis of the p53 key residues for DNA binding indicates high correlations with cancer-related mutations, confirming that impairment of the interactions between p53-DBD and DNA can be frequently related to cancer.

Adaptive immune cell responses as therapeutic targets in antibody-mediated organ rejection.

Humoral alloimmunity of organ transplant recipient to donor can lead to antibody-mediated rejection (ABMR), causing thousands of organ transplants to fail each year worldwide. However, the mechanisms of adaptive immune cell responses at the basis of humoral alloimmunity have not been entirely understood. In this review, we discuss how recent investigations have uncovered the key contributions of T follicular helper (TFH) and B cells and their coordinated actions in driving donor-specific antibody generation and immune progression towards ABMR. We show how recognition of the role of TFH-B cell interactions may allow the elaboration of improved clinical strategies for immune monitoring and the identification of novel therapeutic targets to tackle ABMR that will ultimately improve organ transplant survival.