bims-traimu Biomed News
on Trained immunity
Issue of 2026–07–05
fifteen papers selected by
Yantong Wan, Southern Medical University



  1. Sci Immunol. 2026 Jul 03. 11(121): eaeb7976
      Innate immune memory (trained immunity) is mediated by epigenetic and metabolic reprogramming of innate immune cells and hematopoietic progenitors, enabling altered responses to subsequent challenges. Mechanistically conserved across eukaryotes, trained immunity in mammals operates as a dynamically regulated, life-phase-specific system. The demands and constraints on innate immune memory shift across the life span: from tolerogenic programming and maternal immune transfer in fetal and neonatal life, through establishment of innate set points during early-life microbial colonization, to full integration of central and peripheral training with adaptive immunity in adulthood. Aging disrupts this integration, producing simultaneous immunosenescence and inflammaging, potentially through cumulative maladaptive training at the hematopoietic stem cell level. In this Review, we examine how the exposome continuously shapes innate immune trajectories across life and discuss implications for trained immunity-based strategies to limit maladaptive inflammation.
    DOI:  https://doi.org/10.1126/sciimmunol.aeb7976
  2. iScience. 2026 Jul 17. 29(7): 116496
      Hemodialysis patients experience persistent inflammation marked by pro-inflammatory monocytes. We hypothesized that the hyper-responsiveness of innate immune cells in these patients is facilitated by trained immunity, a form of innate immune memory. Hemodialysis patients displayed elevated monocyte counts, and isolated peripheral blood mononuclear cells showed significantly heightened cytokine responses after Toll-like receptor stimulation, both indicative of trained immunity. Importantly, plasma interferon gamma (IFN-γ) concentrations positively correlated with cytokine responses. Whole-genome RNA-sequencing revealed enrichment of interferon response pathways, particularly in patients whose monocytes exhibited the most pronounced cytokine production upon restimulation. In vitro experiments confirmed that trained immunity induction depends on IFN-γ, produced by CD4+ T cells. Our findings demonstrate that hemodialysis patients display a dysregulated immune response characterized by trained immunity and that this might be mediated by IFN-γ. These insights suggest that targeting IFN-γ could be a promising strategy to mitigate damaging immune hyperactivity in dialysis patients.
    Keywords:  cell biology; immunology; molecular medicine; nephrology; systems biology
    DOI:  https://doi.org/10.1016/j.isci.2026.116496
  3. Cell Rep. 2026 Jul 03. pii: S2211-1247(26)00726-6. [Epub ahead of print]45(7): 117648
      Obesity is associated with profound immune dysregulation, driving chronic inflammation while compromising host defense against tumors. While trained immunity can enhance innate effector functions, it has thus far required parenteral administration of microbial ligands. Here, we show that incorporating a yeast-derived β-glucan supplement in mouse diets induces trained immunity via reprogramming of hematopoietic stem and progenitor cells. This dietary intervention leads to sustained production of metabolically enhanced monocytes and macrophages that rescue anti-tumor immunity in high-fat diet-induced obese mice, and corrects immune dysfunction sustained after weight loss. Our work reveals that yeast β-glucans act as functional "immuno-nutrients," which remodel innate immunity and identifies the mucosal/bone-marrow axis as a target for dietary manipulations to restore immune resilience without impacting metabolism.
    Keywords:  CP: immunology; beta-glucan; dietary supplementation; hematopoiesis; immunometabolism; innate immunity; macrophage; monocyte; obesity; trained immunity; tumor immunity
    DOI:  https://doi.org/10.1016/j.celrep.2026.117648
  4. Acta Pharm Sin B. 2026 Jun;16(6): 3655-3679
      Epigenetic reprogramming underpins trained immunity (TRIM). However, the importance of mRNA reprogramming in TRIM remains unknown. Here, we discovered, for the first time, that the steroid hormone ouabain creates a significant training effect on peripheral innate immune cells (IICs), leading to functional enhancement of IICs against bacterial infections. However, unlike conventional training mechanisms, ouabain primarily relies on an integrated posttranscriptional RNA regulon complex (IPRRC) to establish immune memory and reprogram cytokine expression, with lncRNA-CYTOR playing a critical role in this process. Moreover, to enhance training effects while reducing lactate production, ouabain promotes a rapid degradation of the Na+,K+-ATPase receptor. Pathologically, endogenous ouabain is downregulated in sepsis-induced immunoparalysis in vivo, correlating with impaired innate immunity. Exogenous ouabain rescue significantly reverses this impairment, and its effect is superior to β-glucan, even when used at one percent of β-glucan dosage. Notably, posttranscriptional RNA regulons are also critically involved in β-glucan's training effects. Overall, mRNA reprogramming emerges as a new mechanism for TRIM; steroid hormone ouabain is a novel innate immunity regulator.
    Keywords:  CYTOR; Endotoxin tolerance; Immune training; Innate immune cells; Na+,K+-ATPase; Posttranscriptional RNA regulons; Steroid hormone ouabain; mRNA reprogramming
    DOI:  https://doi.org/10.1016/j.apsb.2025.12.041
  5. Cardiol Rev. 2026 Jul 08.
      Cardiovascular disease remains the leading global cause of death, and a major part of its residual risk is now understood to be inflammatory rather than purely lipid-driven. Immunometabolism provides the missing link between metabolic stress and immune activation: excess lipids, hyperglycemia, and tissue hypoxia reprogram immune and vascular cells toward glycolysis, altered glutamine use, mitochondrial dysfunction, and durable epigenetic memory. In atherosclerosis, this metabolic shift fuels endothelial dysfunction, macrophage foam-cell formation, cytokine release, defective efferocytosis, and plaque instability. The concept extends beyond the plaque itself through trained immunity, in which monocytes and bone marrow progenitors retain a pro-inflammatory memory that can persist after the original trigger has passed. This helps explain why myocardial infarction, diabetes, and hyperlipidemia can leave a long inflammatory imprint on the vasculature. Immunometabolism also contributes to thromboinflammation, where activated platelets, neutrophils, and extracellular traps reinforce clot formation and amplify arterial injury. In heart failure, postischemic remodeling and chronic congestion are accompanied by immune-cell and cardiomyocyte metabolic remodeling that sustains inflammation, fibrosis, and adverse ventricular remodeling. Clinical trials targeting inflammation, especially canakinumab and low-dose colchicine, have shown that suppressing inflammatory pathways can reduce cardiovascular events, supporting the translational value of this biology. A clearer understanding of immunometabolic circuits may enable better risk stratification, biomarker-guided therapy, and new treatments that simultaneously stabilize plaques, reduce thrombosis, and improve postinfarction healing.
    Keywords:  atherosclerosis; cardiovascular outcomes; heart failure; immunometabolism; thromboinflammation; trained immunity
    DOI:  https://doi.org/10.1097/CRD.0000000000001391
  6. Commun Med (Lond). 2026 Jul 02. pii: 358. [Epub ahead of print]6(1):
       BACKGROUND: Immune aging may contribute to Alzheimer's disease. Bacillus Calmette-Guérin (BCG), a vaccine known to induce trained immunity, has been linked to reduced Alzheimer's risk in prior studies. However, whether trained immunity can be observed in the human central nervous system remains unclear. We assessed whether BCG induces trained immunity-like responses in adults with and without Alzheimer's-related changes.
    METHODS: We conducted two related one-year, open-label clinical trials in adults aged 55 years or older (n = 12 without Alzheimer's-related pathology; n = 11 with Alzheimer's-related pathology) recruited at a single center. Participants received two intradermal BCG vaccinations one month apart. Protocol-defined objectives included safety, neurocognitive outcomes, and longitudinal immune and Alzheimer's biomarker changes in blood and cerebrospinal fluid. Immune responses were assessed using cytokine assays and single-cell profiling. All enrolled participants were included where data were available; longitudinal changes were analyzed using mixed-effects models.
    RESULTS: Here we show that BCG induces persistent, trained immunity-like changes in immune cells in cerebrospinal fluid, including enhanced innate responsiveness and associated transcriptional programs. These responses differ from blood, suggesting compartment-specific immune imprinting. In participants without Alzheimer's-related changes, these immune shifts are accompanied by decreased amyloid-β levels in cerebrospinal fluid and increased levels in blood. BCG was well tolerated, with no unexpected safety signals observed.
    CONCLUSIONS: These findings suggest trained immunity-like responses in the central nervous system that may influence Alzheimer's-relevant pathways. This approach may represent an early neurodegenerative intervention strategy, although larger controlled studies are needed to confirm these observations.
    TRIAL REGISTRATION: ClinicalTrials.gov NCT04507126 (June 23, 2020) and NCT05004688 (August 6, 2021).
    DOI:  https://doi.org/10.1038/s43856-026-01691-7
  7. Nat Immunol. 2026 Jul;27(7): 1336-1352
      Inflammatory memory enables cells to remember prior inflammatory signals, shaping their responses to subsequent challenges. While this phenomenon has been extensively characterized in immune cells and various tissues, recent reports suggest that both immune and nonimmune cells in the central nervous system (CNS) also exhibit inflammatory memory. In this Perspective, we synthesize emerging evidence of inflammatory memory in the CNS and discuss its underlying mechanisms. We highlight how epigenomic reprogramming through histone and DNA modifications, the recruitment of epigenetic regulators and nucleosome remodeling drive changes in gene expression kinetics central to inflammatory memory. We also examine mechanisms that maintain or reset inflammatory memory. By identifying shared principles and CNS-specific features, we propose conceptual frameworks to advance our understanding of CNS inflammatory memory and its implications for health and disease.
    DOI:  https://doi.org/10.1038/s41590-026-02541-3
  8. EBioMedicine. 2026 Jul 03. pii: S2352-3964(26)00251-3. [Epub ahead of print]130 106368
       BACKGROUND: Previous transcriptomic studies demonstrated an acute genomic storm in circulating immune cells after trauma that gradually returns to baseline. The magnitude and duration of these changes is associated with post-injury complications. We hypothesised that other immune cell features emerging in the subacute timeframe should be associated with recovery.
    METHODS: We applied DOGMA-seq on peripheral blood mononuclear cells isolated at day 3 after injury from the patients undergoing slow or fast recovery from critical illness (n = 8/group), along with age-and-sex matched healthy controls. We explored the functional responses of newly identified gene co-expression networks using in vitro cell culture (GM-CSF or M-CSF induced macrophage differentiation) followed by scRNA-seq.
    FINDINGS: We identified a subset of CD172a hi/MHCII hi, CD14+ monocytes that were distinct from baseline, and overrepresented in patients that recovered faster and associated with changes in several key gene co-expression networks. A gene co-expression pattern associated with chemotaxis and cell adhesion was overrepresented in patients with fast recovery and, specifically associated with increased accessibility of AP1 family motifs, continuously deviating from baseline, and favouring a response to M-CSF rather than GM-CSF during macrophage differentiation.
    INTERPRETATION: Our findings add a new information layer to the current paradigm by demonstrating that recovery is not simply a return to the baseline state and instead involves the emergence of new monocyte subset with new transcriptomic programs that may influence the macrophage response.
    FUNDING: National Institutes of Health R35 grant R35GM127027 (T.B.).
    Keywords:  DOGMA-seq; Macrophages; Monocytes; Trauma; scRNA-seq
    DOI:  https://doi.org/10.1016/j.ebiom.2026.106368
  9. Sci Immunol. 2026 Jul 03. 11(121): eaej2527
      Multilayered immune memory contributes to lifelong pathogen protection and health.
    DOI:  https://doi.org/10.1126/sciimmunol.aej2527
  10. bioRxiv. 2026 Jun 25. pii: 2026.06.25.734552. [Epub ahead of print]
      Clinical data link the prevalent respiratory tract anaerobe Prevotella with reduced pneumonia mortality, but the mechanisms directing Prevotella regulation of lung immune homeostasis are unclear. Here, single-cell RNA sequencing was employed to define the transcriptional immune signatures underlying improved clearance of Streptococcus pneumoniae following lung exposure to Prevotella melaninogenica . Overall, we observed a substantial shift in myeloid cell transcriptional programming from interferon-dominant to a more antibacterial profile in S. pneumoniae -infected mice after pre-exposure to P. melaninogenica , correlating with increased macrophage and neutrophil phagocytosis of S. pneumoniae and improved pathogen clearance. In neutrophils, TNF signaling through TNFR2 was essential for increased antimicrobial function. Moreover, improved defense required CCR2-dependent monocyte-derived macrophages, with selective enrichment of more a mature Cxcl3+ population which was distinct from the hallmark S. pneumoniae -associated C1qa+ population enriched in the absence of effective clearance. Together, these findings inform the myeloid cell transcriptional changes associated with natural infection resistance mediated by pulmonary microbial exposures.
    DOI:  https://doi.org/10.64898/2026.06.25.734552
  11. Cell Rep. 2026 Jun 26. pii: S2211-1247(26)00682-0. [Epub ahead of print]45(7): 117604
      Toll-like receptor (TLR) activation elicits an effective innate immune response by inducing the expression of primary and secondary response genes (PRGs and SRGs). Topoisomerase 1 (TOP1) has emerged as a critical regulator of innate immune responses; however, its mechanism of action remains largely unclear. Here, we demonstrate that the ectopic expression of TOP1 is sufficient to program TLR-response in naive macrophages, and its catalytic activity is essential for inducible gene expression. TOP1 preferentially localizes to super-enhancers, and TLR activation results in the rapid redistribution of TOP1 from resting-state super-enhancers to stimulus-gained super-enhancers, leading to a transcriptional switch. Notably, TOP1 facilitates the recruitment of BRG1 to stimulus-gained super-enhancers. The cooperation between TOP1 and BRG1 enhances the chromatin accessibility at super-enhancers to preferentially regulate the expression of SRGs. These findings establish TOP1 as a transcriptional regulator that links chromatin remodeling at active super-enhancers with inducible gene expression in response to pathogenic stimuli.
    Keywords:  BRG1; CP: immunology; CP: molecular biology; bone marrow-derived macrophages; super-enhancers; toll-like receptor; topoisomerase 1
    DOI:  https://doi.org/10.1016/j.celrep.2026.117604
  12. Nat Metab. 2026 Jul 03.
      Post-translational modifications (PTMs) dynamically regulate protein function, with metabolite-driven PTMs linking metabolism to protein regulation1,2. We have previously discovered lysine lactylation, showing that lactate can directly modify proteins and influence cancer progression3,4. Recently, pyruvate, another glycolytic metabolite, was shown to directly modify STAT1 at lysine 201, thereby suppressing type I interferon signalling5. Yet, the enzyme governing this modification, its substrate landscape and potential roles beyond innate immunity remain entirely unexplored. Here we report the systematic characterization of lysine pyruvylation (Kpy). Through biochemical and proteomic approaches, we establish the widespread existence of this modification, identifying 88 Kpy sites in mammalian cells. We investigate the dynamic regulation of Kpy upon metabolic perturbations and find that Kpy fluctuates with changes in glycolytic flux and pyruvate levels. Furthermore, we identify sirtuin 3 (SIRT3) as responsible for removing Kpy, while histone acetyltransferase 1 (HAT1) and p300 (EP300) catalyse its addition. Finally, we explore the function of Kpy in transcriptional regulation. Overall, Kpy expands the repertoire of metabolite-driven PTMs and provides insights into how pyruvate directly modulates protein function.
    DOI:  https://doi.org/10.1038/s42255-026-01556-2
  13. Shock. 2026 Jun 30.
      Body temperature generally correlates with mortality in mouse sepsis. However, single temperature measurements fail to accurately discriminate whether mice will subsequently live or die following a septic insult, limiting their usefulness as an endpoint in pre-clinical sepsis studies. Temperature trajectories using serial measurements have been demonstrated to have predictive capacity in septic patients. The purpose of this study was to determine if temperature trajectories could predict subsequent mortality in septic mice. A cohort of 511 C57Bl/6 mice from three different laboratories undergoing survival experiments had serial body temperature measured every 12 hours from baseline to 7 days following the onset of sepsis. To optimize generalizability, the cohort was intentionally heterogeneous, including 6-31 week old mice with an equal number of females and males undergoing three different models of sepsis with different comorbidities prior to sepsis, and different genetic variants. A training cohort comprised the first 80% (n=417) and a validation cohort comprised the final 20% (n=94). To quantitatively predict mortality risk following sepsis, a Bayesian joint model was developed incorporating longitudinal temperature measurements using data collected at baseline and 12 and 24 hours after the onset of sepsis to predict probability of death in the subsequent 12-72 hours. Predictive accuracy improved progressively with longer horizons with AUCs increasing from 0.864 at 12 hours (predicting 24-36 hour mortality) to 0.932 at 72 hours (predicting 24-96 hour mortality) in the training cohort. Model performance was not improved by incorporating type of sepsis model, age or sex as covariates. While specificity was >0.92 at all timepoints in the training cohort, it was only 0.796 at both 24 and 36 hours in the validation cohort. Since a specificity <1 means that some mice predicted to die would instead survive leading to errors in survival curve, an additional pre-specificed analysis was independently evaluated to identify irreversible terminal states where no mouse ended up surviving. At 24, 36 and 48 hours, temperature thresholds of 27.0 °C, 28.2 °C and 30.2 °C identified mice that would subsequently die with a specificity of 1. Temperature trajectories identifying longitudinal hypothermia therefore represent a powerful predictor of mortality in a large heterogeneous population of murine sepsis. Whereas a single temperature measurement has limitations in prediction of subsequent mortality except at extreme hypothermia, dynamic Bayesian modeling enables individualized mortality risk estimation as criteria that may be used for humane endpoint determination.
    DOI:  https://doi.org/10.1097/SHK.0000000000002901