ABSTRACT
Purpose: Early identification of new residual risk factors for coronary heart disease (CHD) is warranted. In this study, we aim to investigate the association between the serine concentration, an important amino acid in one-carbon metabolism, and CHD in Chinese hospitalized patients. Patients and Methods: This case-control study included 428 case-control pairs comprising patients with CHD with a maximum coronary artery stenosis degree of >70% and controls with stenosis of <30%. The individuals were matched by age, sex, and date of coronary angiography at Peking University First Hospital from January 1, 2016, to December 31, 2019. Conditional logistic regression was used to investigate the associations between the serine concentration and CHD. Results: Patients with CHD were aged 63.48 ± 10.38 years, and 43.73% were male. Compared with controls, patients with CHD had a slightly lower serine concentration (13.35 ± 4.20 vs 13.77 ± 4.08 µg/mL), but the difference was not significant. In the multivariable conditional logistic regression analysis, for every 1 µg/mL increase in serine concentration, the odds of CHD decreased by 6% (95% confidence interval [CI] 0.90-0.99; P = 0.010). Patients with a serine concentration of ≥13.41 µg/mL had a lower CHD risk than those with a serine concentration of <13.41 µg/mL (odds ratio [OR] 0.57, 95% CI 0.39-0.84; P = 0.004). Subgroup analyses showed that sex interacted with the relationship between serine concentration and CHD (P interaction = 0.039), which was more significant in males (OR 0.93, 95% CI 0.87-0.98; P = 0.013) than in females. Conclusion: This study observed an inverse association between the serine concentration and CHD prevalence in Chinese hospitalized patients, which revealed that serine might play a protective role in CHD.
ABSTRACT
Rice is one of the most important staple food and model species in plant biology, yet its quantitative proteomes are largely uncharacterized. Here we quantify the relative protein levels of over 15,000 genes across major rice tissues using a tandem mass tag strategy followed by intensive fractionation and mass spectrometry. We identify tissue-specific and tissue-enriched proteins that are linked to the functional specificity of individual tissues. Proteogenomic comparison of rice and Arabidopsis reveals conserved proteome expression, which differs from mammals in that there is a strong separation of species rather than tissues. Notably, profiling of N6-methyladenosine (m6A) across the rice major tissues shows that m6A at untranslated regions is negatively correlated with protein abundance and contributes to the discordance between RNA and protein levels. We also demonstrate that our data are valuable for identifying novel genes required for regulating m6A methylation. Taken together, this study provides a paradigm for further research into rice proteogenome.
ABSTRACT
We evaluated the BYSL content and underlying mechanism in melanoma (SKCM) overall survival (OS). In this study, we used a comprehensive approach combining bioinformatics tools, including miRNA estimation, quantitative real-time polymerase chain reaction (qRT-PCR) of miRNAs, E3 ligase estimation, STRING analysis, TIMER analysis, examination of associated upstream modulators, protein-protein interaction (PPI) analysis, as well as retrospective and survival analyses, alongside clinical sample validation. These methods were used to investigate the content of BYSL, its methylation status, its relation to patient outcome, and its immunologic significance in tumors. Our findings revealed that BYSL expression is negatively regulated by BYSL methylation. Analysis of 468 cases of SKCM RNA sequencing samples demonstrated that enhanced BYSL expression was associated with higher tumor grade. We identified several miRNAs, namely hsa-miR-146b-3p, hsa-miR-342-3p, hsa-miR-511-5p, hsa-miR-3690, and hsa-miR-193a-5p, which showed a strong association with BYSL levels. Furthermore, we predicted the E3 ubiquitin ligase of BYSL and identified CBL, FBXW7, FZR1, KLHL3, and MARCH1 as potential modulators of BYSL. Through our investigation, we discovered that PNO1, RIOK2, TSR1, WDR3, and NOB1 proteins were strongly associated with BYSL expression. In addition, we found a close association between BYSL levels and certain immune cells, particularly dendritic cells (DCs). Notably, we observed a significant negative correlation between miR-146b-3p and BYSL mRNA expression in SKCM sera samples. Collectively, based on the previously shown evidences, BYSL can serve as a robust bioindicator of SKCM patient prognosis, and it potentially contributes to immune cell invasion in SKCM.
ABSTRACT
This study is aimed to examine the association of plasma homocysteine (Hcy) concentrations with a 10-year risk of all-cause and cardiovascular (CV) mortality and to explore the modification effect of methylenetetrahydrofolate reductase (MTHFR) C677T genetic polymorphism. This study included 5200 participants from a community-based Chinese population. Cox proportional hazard regression models were used to analyze the associations of Hcy and MTHFR C677T genotype with all-cause and CV mortality. The possible modification effect of the MTHFR C677T genotype on the Hcy-mortality relationship was assessed. The individuals with Hcy concentrations ≥ 10 µmol/L had a significantly higher risk of all-cause mortality compared to those with Hcy < 10 µmol/L (hazard ratio [HR]: 1.72, 95% confidence interval [CI]: 1.11-2.68, p = 0.015). The risk of CV mortality increased by 2% per 1 µmol/L Hcy increment (HR: 1.02, 95% CI: 1.00-1.03, p = 0.036). Despite the MTHFR genotype alone not being correlated with the mortality, the relationship between Hcy and all-cause mortality was significant in the CC genotype compared with CT/TT genotype (p for interaction = 0.036). Elevated plasma Hcy concentrations were associated with an increased 10-year risk of all-cause and CV mortality among the Chinese population. MTHFR C677T genetic polymorphism could modify the association between Hcy and all-cause mortality.
Subject(s)
Asian People , Cardiovascular Diseases , Homocysteine , Methylenetetrahydrofolate Reductase (NADPH2) , Humans , Homocysteine/blood , Male , Female , Methylenetetrahydrofolate Reductase (NADPH2)/genetics , Cardiovascular Diseases/mortality , Cardiovascular Diseases/blood , Middle Aged , China/epidemiology , Asian People/genetics , Risk Factors , Genotype , Aged , Proportional Hazards Models , Adult , Cause of Death , Polymorphism, Single Nucleotide , Genetic Predisposition to Disease , East Asian PeopleABSTRACT
[This corrects the article DOI: 10.3389/fonc.2022.951973.].
ABSTRACT
Introduction: A hallmark of T cell dysregulation during sepsis is the downregulation of costimulatory molecules. CD28 is one of T cell costimulatory molecules significantly altered on memory T cells during sepsis. We recently showed that treatment with a αCD28 agonist in septic immunologically experienced mice led to improved survival. Therefore, here we aimed to identify the cell subset(s) necessary for the survival benefit observed in the context of CD28 agonism, and to further investigate the mechanism by which CD28 agonism improves sepsis survival in immunologically experienced mice. Methods: Mice received specific pathogen inoculation to generate memory T cell populations similar in frequency to that of adult humans. Once these infections were cleared and the T cell response had transitioned to the memory phase, animals were rendered septic via cecal ligation and puncture in the presence or absence of an agonistic anti-CD28 mAb. Results: Results demonstrated that CD8+ T cells, and not bulk CD4+ T cells or CD25+ regulatory T cells, were necessary for the survival benefit observed in CD28 agonist-treated septic immunologically experienced mice. Upon examination of these CD8+ T cells, we found that CD28 agonism in septic immunologically experienced mice was associated with an increase in Foxp3+ CD8+ T cells as compared to vehicle-treated controls. When CD8+ T cells were depleted in septic immunologically experienced mice in the setting of CD28 agonism, a significant increase in levels of inflammatory cytokines in the blood was observed. Discussion: Taken together, these results indicate that CD28 agonism in immunologically experienced mice effectively suppresses inflammation via a CD8+-dependent mechanism to decrease mortality during sepsis.
Subject(s)
CD8-Positive T-Lymphocytes , Sepsis , Animals , Humans , Mice , CD28 Antigens/agonists , CD8-Positive T-Lymphocytes/immunology , Sepsis/immunology , Sepsis/mortality , T-Lymphocytes, RegulatoryABSTRACT
Intestinal epithelial expression of the tight junction protein claudin-2, which forms paracellular cation and water channels, is precisely regulated during development and in disease. Here, we show that small intestinal epithelial claudin-2 expression is selectively upregulated in septic patients. Similar changes occurred in septic mice, where claudin-2 upregulation coincided with increased flux across the paracellular pore pathway. In order to define the significance of these changes, sepsis was induced in claudin-2 knockout (KO) and wild-type (WT) mice. Sepsis-induced increases in pore pathway permeability were prevented by claudin-2 KO. Moreover, claudin-2 deletion reduced interleukin-17 production and T cell activation and limited intestinal damage. These effects were associated with reduced numbers of neutrophils, macrophages, dendritic cells, and bacteria within the peritoneal fluid of septic claudin-2 KO mice. Most strikingly, claudin-2 deletion dramatically enhanced survival in sepsis. Finally, the microbial changes induced by sepsis were less pathogenic in claudin-2 KO mice as survival of healthy WT mice injected with cecal slurry collected from WT mice 24 h after sepsis was far worse than that of healthy WT mice injected with cecal slurry collected from claudin-2 KO mice 24 h after sepsis. Claudin-2 upregulation and increased pore pathway permeability are, therefore, key intermediates that contribute to development of dysbiosis, intestinal damage, inflammation, ineffective pathogen control, and increased mortality in sepsis. The striking impact of claudin-2 deletion on progression of the lethal cascade activated during sepsis suggests that claudin-2 may be an attractive therapeutic target in septic patients.
Subject(s)
Claudin-2 , Sepsis , Animals , Humans , Mice , Claudin-2/genetics , Claudin-2/metabolism , Dysbiosis/genetics , Dysbiosis/metabolism , Intestinal Barrier Function , Intestinal Mucosa/metabolism , Permeability , Sepsis/metabolism , Tight Junctions/metabolism , Up-RegulationABSTRACT
N6 -methyladenosine (m6 A) is the most abundant mRNA modification in eukaryotes and is an important regulator of gene expression as well as many other critical biological processes. However, the characteristics and functions of m6 A in peanut (Arachis hypogea L.) resistance to bacterial wilt (BW) remain unknown. Here, we analyzed the dynamic of m6 A during infection of resistant (H108) and susceptible (H107) peanut accessions with Ralstonia solanacearum (R. solanacearum), the causative agent of BW. Throughout the transcriptome, we identified 'URUAY' as a highly conserved motif for m6 A in peanut. The majority of differential m6 A located within the 3' untranslated region (UTR) of the transcript, with fewer in the exons. Integrative analysis of RNA-Seq and m6 A methylomes suggests the correlation between m6 A and gene expression in peanut R. solanacearum infection, and functional analysis reveals that m6 A-associated genes were related to plant-pathogen interaction. Our experimental analysis suggests that AhALKBH15 is an m6 A demethylase in peanut, leading to decreased m6 A levels and upregulation of the resistance gene AhCQ2G6Y. The upregulation of AhCQ2G6Y expression appears to promote BW resistance in the H108 accession.
Subject(s)
Arachis , Ralstonia solanacearum , Arachis/genetics , Transcriptome , Up-Regulation , RNA , Plant Diseases/genetics , Plant Diseases/microbiologyABSTRACT
Chronic alcohol use increases morbidity and mortality in the setting of sepsis. Both chronic alcohol use and sepsis are characterized by immune dysregulation, including overexpression of T cell coinhibitory molecules. We sought to characterize the role of CTLA-4 during sepsis in the setting of chronic alcohol exposure using a murine model of chronic alcohol ingestion followed by cecal ligation and puncture. Results indicated that CTLA-4 expression is increased on CD4+ T cells isolated from alcohol-drinking septic mice as compared with either alcohol-drinking sham controls or water-drinking septic mice. Moreover, checkpoint inhibition of CTLA-4 improved sepsis survival in alcohol-drinking septic mice, but not water-drinking septic mice. Interrogation of the T cell compartments in these animals following pharmacologic CTLA-4 blockade, as well as following conditional Ctla4 deletion in CD4+ T cells, revealed that CTLA-4 deficiency promoted the activation and proliferation of effector regulatory T cells and the generation of conventional effector memory CD4+ T cells. These data highlight an important role for CTLA-4 in mediating mortality during sepsis in the setting of chronic alcohol exposure and may inform future approaches to develop targeted therapies for this patient population.
Subject(s)
Ethanol , Immune Checkpoint Inhibitors , Sepsis , Animals , Mice , CD4-Positive T-Lymphocytes , CTLA-4 Antigen , Ethanol/adverse effects , Memory T Cells , Sepsis/drug therapy , Immune Checkpoint Inhibitors/therapeutic useABSTRACT
Despite the importance of Nitric Oxide (NO) as signaling molecule in both plant and animal development, the regulatory mechanisms downstream of NO remain largely unclear. Here, we show that NO is involved in Arabidopsis shoot stem cell control via modifying expression and activity of ARGONAUTE 4 (AGO4), a core component of the RNA-directed DNA Methylation (RdDM) pathway. Mutations in components of the RdDM pathway cause meristematic defects, and reduce responses of the stem cell system to NO signaling. Importantly, we find that the stem cell inducing WUSCHEL transcription factor directly interacts with AGO4 in a NO dependent manner, explaining how these two signaling systems may converge to modify DNA methylation patterns. Taken together, our results reveal that NO signaling plays an important role in controlling plant stem cell homeostasis via the regulation of de novo DNA methylation.
Subject(s)
Arabidopsis Proteins , Arabidopsis , DNA Methylation/genetics , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Nitric Oxide/metabolism , Meristem/genetics , Meristem/metabolism , Arabidopsis/metabolism , RNA/metabolism , Gene Expression Regulation, PlantABSTRACT
Alkaline aqueous zinc-ion batteries possess a wider potential window than those in mildly acidic systems; they can achieve high energy density and are expected to become the next generation of energy storage devices. In this paper, a hollow porous P-NiCo2O4@Co3O4 nanoarray is obtained by ion etching and the calcination and phosphating of ZiF-67, which is directly grown on foam nickel substrate, as a precursor. It exhibits excellent performance as a cathode material for alkaline aqueous zinc-ion batteries. A high discharge specific capacity of 225.3 mAh g-1 is obtained at 1 A g-1 current density, and it remains 81.9% when the current density is increased to 10 A g-1. After one thousand cycles of charging and discharging at 3 A g-1 current density, the capacity retention rate is 88.8%. Even at an excellent power density of 25.5 kW kg-1, it maintains a high energy density of 304.5 Wh kg-1. It is a vital, promising high-power energy storage device for large-scale applications.
Subject(s)
Body Fluids , Zinc , Porosity , CobaltABSTRACT
NEB mutation is associated with congenital nemaline myopathies. Here, we report a family with recurrent prenatal arthrogryposis. Trio whole exome sequencing (WES) disclosed three novel NEB (NM_001271208.2) variants including one paternal frameshift c.19049_19050delCA (p.Thr6350Argfs*14) and two double maternal variants in cis c. [24871G>T;24871-10C>G] (p. [Val8291Phe;?]). They are evaluated as "likely pathogenic (LP)", "variant of uncertain of significance (VUS)", and "VUS", respectively. After further prediction, the c.24871G>T, c.24871-10C>G, and c.[24871G>T;24871-10C>G] were respectively genetically engineered into the three plasmids. Compared with their wild-type counterparts, the three plasmids all produced truncated transcripts, and also a significant proportion of the full-length transcripts, which allowed us to reclassify NEB c.24871G>T and c.24871-10C>G variants as LP. As far as we know, this is the first case carrying NEB allele-specific function of partial loss. This result helped the couple make informed reproductive choices and opt for assisted reproduction for future pregnancies. This study also increased awareness to the phenotype of prenatal nemaline myopathy and expanded the variant spectrum of NEB.
ABSTRACT
The large intestine harbors microorganisms playing unique roles in host physiology. The beneficial or detrimental outcome of host-microbiome coexistence depends largely on the balance between regulators and responder intestinal CD4+ T cells. We found that ulcerative colitis-like changes in the large intestine after infection with the protist Blastocystis ST7 in a mouse model are associated with reduction of anti-inflammatory Treg cells and simultaneous expansion of pro-inflammatory Th17 responders. These alterations in CD4+ T cells depended on the tryptophan metabolite indole-3-acetaldehyde (I3AA) produced by this single-cell eukaryote. I3AA reduced the Treg subset in vivo and iTreg development in vitro by modifying their sensing of TGFß, concomitantly affecting recognition of self-flora antigens by conventional CD4+ T cells. Parasite-derived I3AA also induces over-exuberant TCR signaling, manifested by increased CD69 expression and downregulation of co-inhibitor PD-1. We have thus identified a new mechanism dictating CD4+ fate decisions. The findings thus shine a new light on the ability of the protist microbiome and tryptophan metabolites, derived from them or other sources, to modulate the adaptive immune compartment, particularly in the context of gut inflammatory disorders.
Subject(s)
Gastrointestinal Microbiome , Microbiota , Animals , Mice , Eukaryota/metabolism , Tryptophan/metabolism , T-Lymphocytes, RegulatoryABSTRACT
ABSTRACT: Alcohol use disorder is associated with increased mortality in septic patients. Murine studies demonstrate that ethanol/sepsis is associated with changes in gut integrity. This study examined intestinal permeability after ethanol/sepsis and investigated mechanisms responsible for alterations in barrier function. Mice were randomized to drink either 20% ethanol or water for 12 weeks and then were subjected to either sham laparotomy or cecal ligation and puncture (CLP). Intestinal permeability was disproportionately increased in ethanol/septic mice via the pore, leak, and unrestricted pathways. Consistent with increased permeability in the leak pathway, jejunal myosin light chain (MLC) kinase (MLCK) expression and the ratio of phospho-MLC to total MLC were both increased in ethanol/CLP. Gut permeability was altered in MLCK -/- mice in water/CLP; however, permeability was not different between WT and MLCK -/- mice in ethanol/CLP. Similarly, jejunal IL-1ß levels were decreased while systemic IL-6 levels were increased in MLCK -/- mice in water/CLP but no differences were identified in ethanol/CLP. While we have previously shown that mortality is improved in MLCK -/- mice after water/CLP, mortality was significantly worse in MLCK -/- mice after ethanol/CLP. Consistent with an increase in the pore pathway, claudin 4 levels were also selectively decreased in ethanol/CLP WT mice. Furthermore, mRNA expression of jejunal TNF and IFN-γ were both significantly increased in ethanol/CLP. The frequency of CD4 + cells expressing TNF and IL-17A and the frequency of CD8 + cells expressing IFN-γ in Peyer's Patches were also increased in ethanol/CLP. Thus, there is an ethanol-specific worsening of gut barrier function after CLP that impacts all pathways of intestinal permeability, mediated, in part, via changes to the tight junction. Differences in the host response in the setting of chronic alcohol use may play a role in future precision medicine approaches toward the treatment of sepsis.
Subject(s)
Sepsis , Tight Junctions , Animals , Mice , Ethanol , Immunity , Intestinal Mucosa/metabolism , Punctures , Sepsis/metabolism , Tight Junctions/metabolismABSTRACT
PURPOSE: The diagnosis of obstructive sleep apnea (OSA) relies on time-consuming and complicated procedures which are not always readily available and may delay diagnosis. With the widespread use of artificial intelligence, we presumed that the combination of simple clinical information and imaging recognition based on facial photos may be a useful tool to screen for OSA. METHODS: We recruited consecutive subjects suspected of OSA who had received sleep examination and photographing. Sixty-eight points from 2-dimensional facial photos were labelled by automated identification. An optimized model with facial features and basic clinical information was established and tenfold cross-validation was performed. Area under the receiver operating characteristic curve (AUC) indicated the model's performance using sleep monitoring as the reference standard. RESULTS: A total of 653 subjects (77.2% males, 55.3% OSA) were analyzed. CATBOOST was the most suitable algorithm for OSA classification with a sensitivity, specificity, accuracy, and AUC of 0.75, 0.66, 0.71, and 0.76 respectively (P < 0.05), which was better than STOP-Bang questionnaire, NoSAS scores, and Epworth scale. Witnessed apnea by sleep partner was the most powerful variable, followed by body mass index, neck circumference, facial parameters, and hypertension. The model's performance became more robust with a sensitivity of 0.94, for patients with frequent supine sleep apnea. CONCLUSION: The findings suggest that craniofacial features extracted from 2-dimensional frontal photos, especially in the mandibular segment, have the potential to become predictors of OSA in the Chinese population. Machine learning-derived automatic recognition may facilitate the self-help screening for OSA in a quick, radiation-free, and repeatable manner.
Subject(s)
Artificial Intelligence , Sleep Apnea, Obstructive , Male , Humans , Female , Automated Facial Recognition , Polysomnography/methods , Surveys and Questionnaires , Machine Learning , Mass ScreeningABSTRACT
Signal transduction induced by chimeric antigen receptors (CARs) is generally believed to rely on the activity of the SRC family kinase (SFK) LCK, as is the case with T cell receptor (TCR) signaling. Here, we show that CAR signaling occurs in the absence of LCK. This LCK-independent signaling requires the related SFK FYN and a CD28 intracellular domain within the CAR. LCK-deficient CAR-T cells are strongly signaled through CAR and have better in vivo efficacy with reduced exhaustion phenotype and enhanced induction of memory and proliferation. These distinctions can be attributed to the fact that FYN signaling tends to promote proliferation and survival, whereas LCK signaling promotes strong signaling that tends to lead to exhaustion. This non-canonical signaling of CAR-T cells provides insight into the initiation of both TCR and CAR signaling and has important clinical implications for improvement of CAR function.
Subject(s)
Receptors, Chimeric Antigen , Proto-Oncogene Proteins/metabolism , CD28 Antigens , Lymphocyte Specific Protein Tyrosine Kinase p56(lck)/metabolism , T-Lymphocytes , Receptors, Antigen, T-Cell , Proto-Oncogene Proteins c-fyn , Signal TransductionABSTRACT
ABSTRACT: Increased epithelial permeability in sepsis is mediated via disruptions in tight junctions, which are closely associated with the perijunctional actin-myosin ring. Genetic deletion of myosin light chain kinase (MLCK) reverses sepsis-induced intestinal hyperpermeability and improves survival in a murine model of intra-abdominal sepsis. In an attempt to determine the generalizability of these findings, this study measured the impact of MLCK deletion on survival and potential associated mechanisms following pneumonia-induced sepsis. MLCK -/- and wild-type mice underwent intratracheal injection of Pseudomonas aeruginosa . Unexpectedly, survival was significantly worse in MLCK -/- mice than wild-type mice. This was associated with increased permeability to Evans blue dye in bronchoalveolar lavage fluid but not in tissue homogenate, suggesting increased alveolar epithelial leak. In addition, bacterial burden was increased in bronchoalveolar lavage fluid. Cytokine array using whole-lung homogenate demonstrated increases in multiple proinflammatory and anti-inflammatory cytokines in knockout mice. These local pulmonary changes were associated with systemic inflammation with increased serum levels of IL-6 and IL-10 and a marked increase in bacteremia in MLCK -/- mice. Increased numbers of both bulk and memory CD4 + T cells were identified in the spleens of knockout mice, with increased early and late activation. These results demonstrate that genetic deletion of MLCK unexpectedly increases mortality in pulmonary sepsis, associated with worsened alveolar epithelial leak and both local and systemic inflammation. This suggests that caution is required in targeting MLCK for therapeutic gain in sepsis.
Subject(s)
Lung , Myosin-Light-Chain Kinase , Pneumonia , Sepsis , Animals , Mice , Cytokines , Inflammation , Intestinal Mucosa , Lung/metabolism , Lung/pathology , Mice, Knockout , Myosin-Light-Chain Kinase/genetics , Permeability , Pneumonia/complications , Sepsis/pathology , Tight Junctions/physiologyABSTRACT
RIPK3 (receptor-interacting protein kinase 3) activity triggers cell death via necroptosis, whereas scaffold function supports protein binding and cytokine production. To determine if RIPK3 kinase or scaffold domains mediate pathology during Pseudomonas aeruginosa infection, control mice and those with deletion or mutation of RIPK3 and associated signaling partners were subjected to Pseudomonas pneumonia and followed for survival or killed for biologic assays. Murine immune cells were studied in vitro for Pseudomonas-induced cytokine production and cell death, and RIPK3 binding interactions were blocked with the viral inhibitor M45. Human tissue effects were assayed by infecting airway epithelial cells with Pseudomonas and measuring cytokine production after siRNA inhibition of RIPK3. Deletion of RIPK3 reduced inflammation and decreased animal mortality after Pseudomonas pneumonia. RIPK3 kinase inactivation did neither. In cell culture, RIPK3 was dispensable for cell killing by Pseudomonas and instead drove cytokine production that required the RIPK3 scaffold domain but not kinase activity. Blocking the RIP homotypic interaction motif (RHIM) with M45 reduced the inflammatory response to infection in vitro. Similarly, siRNA knockdown of RIPK3 decreased infection-triggered inflammation in human airway epithelial cells. Thus, the RIPK3 scaffold drives deleterious pulmonary inflammation and mortality in a relevant clinical model of Pseudomonas pneumonia. This process is distinct from kinase-mediated necroptosis, requiring only the RIPK3 RHIM. Inhibition of RHIM signaling is a potential strategy to reduce lung inflammation during infection.
Subject(s)
Pneumonia , Pseudomonas aeruginosa , Animals , Humans , Mice , Pseudomonas aeruginosa/metabolism , Apoptosis , Inflammation/metabolism , RNA, Small Interfering , Cytokines/metabolism , Receptor-Interacting Protein Serine-Threonine Kinases/geneticsABSTRACT
T cell activation and effector functions are determined by the affinity of the interaction between T cell receptor (TCR) and its antigenic peptide MHC (pMHC) ligand. A better understanding of the quantitative aspects of TCR-pMHC affinity-dependent T cell activation is critical for the development of new immunotherapeutic strategies. However, the role of TCR-pMHC affinity in regulating the kinetics of CD8+ T cell commitment to proliferation and differentiation is unknown. Here, we show that the stronger the TCR-pMHC affinity, the shorter the time of T cell-APC co-culture required to commit CD8+ T cells to proliferation. The time threshold for T cell cytokine production is much lower than that for cell proliferation. There is a strong correlation between affinity-dependent differences in AKT phosphorylation and T cell proliferation. The cytokine IL-15 increases the poor proliferation of T cells stimulated with low affinity pMHC, suggesting that pro-inflammatory cytokines can override the affinity-dependent features of T cell proliferation.