bims-imseme Biomed News
on Immunosenescence and T cell metabolism
Issue of 2026–05–17
thirty-one papers selected by
Pierpaolo Ginefra, Ludwig Institute for Cancer Research



  1. Immunity. 2026 May 12. pii: S1074-7613(26)00168-8. [Epub ahead of print]59(5): 1171-1173
      Tumors present metabolic challenges for T cells. In this issue of Immunity, Scaglione et al. show that CD8+ T cells adapt to nutrient stress through biosynthetic plasticity, coupling translational reprioritization to metabolic reprogramming, preserving effector function and supporting antitumor immunity.
    DOI:  https://doi.org/10.1016/j.immuni.2026.04.006
  2. Int Rev Immunol. 2026 May 13. 1-16
      Using cytotoxic CD8+ T cell-mediated cellular immunity has shown considerable efficacy in cancer treatment. However, the effectiveness of these cells against solid tumors is limited by the presence of an immunosuppressive tumor microenvironment (TME), which constitutes complex networks of regulatory pathways and resistance mechanisms. Given its critical role in TME deterioration through shedding of immunosuppressive molecules from tumor and immune cell surfaces, the upregulation of A Disintegrin and Metalloproteinase 10 (ADAM10) expression can reinforce CD8+ T cells into a state of exhaustion. This paper highlights the influence of ADAM10 and its proteolytic products on the primary pathways of CD8+ T cell exhaustion, including the expression of immune checkpoint molecules and modification across CD8+ T cell transcriptional, metabolic, and nutritional states. We remain optimistic about the critical role of ADAM10 in cytokine-induced T cell exhaustion, recruitment of immunosuppressive cells into the TME, and CD8+ T cell death/survival. Gaining significant insights into these processes may offer new strategies to advance CD8+ T cell-mediated cancer therapy.
    Keywords:  +T cell exhaustion; +T cell therapy; CD8; solid tumors; tumor microenvironment (TME); upregulation of ADAM10 expression
    DOI:  https://doi.org/10.1080/08830185.2026.2669732
  3. Cancers (Basel). 2026 May 03. pii: 1474. [Epub ahead of print]18(9):
      Amino acids are essential nutrients for both tumor growth and immune cell function. Cancer cells actively deplete intracellular and extracellular amino acid pools, and limited amino acid availability in the tumor microenvironment (TME) reinforces immunosuppression. Mitochondria are not merely adenosine triphosphate-producing organelles. Amino acid metabolism within mitochondria contributes to tumor progression and influences immune cell fate and effector function. These effects are mediated through biosynthetic precursor generation for lipid, nucleotide, and polyamine synthesis, maintenance redox homeostasis through glutathione and NAD+ metabolism, and regulation of gene expression through aryl hydrocarbon receptor signaling. In this review, we discuss four major mitochondrial amino acid metabolic pathways: glutamine-driven anaplerosis, serine/glycine-dependent one-carbon metabolism, arginine-ornithine metabolism, and tryptophan-kynurenine metabolism. We examine how these pathways are rewired in cancer cells, how they influence immune cell function through direct or mitochondria-associated mechanisms, and how such metabolic reprogramming promotes tumor progression while impairing antitumor immunity. Finally, we consider therapeutic strategies to improve cancer immunotherapy by targeting amino acid metabolism, including mitochondrial metabolic enzymes. This review may help guide the development of more effective metabolic biomarkers and mitochondria-based therapeutic strategies for cancer immunotherapy.
    Keywords:  amino acid metabolism; antitumor immunity; immunotherapy resistance; mitochondrial metabolism; tumor microenvironment
    DOI:  https://doi.org/10.3390/cancers18091474
  4. Immunity. 2026 May 14. pii: S1074-7613(26)00176-7. [Epub ahead of print]
      Changes in peripheral CD8+ T cells are a hallmark of immune aging. However, the role of aged non-infiltrating CD8+ T cells in brain aging remains to be fully defined. Here, we showed that aged circulating CD8+ T cells and their secreted factors drove hippocampal-dependent cognitive decline. Using heterochronic parabiosis and transcriptomics analysis, we observed that peripheral CD8+ T cells maintained properties intrinsic to their age. Systemic exposure of young mice to aged CD8+ T cells elicited synaptic-related hippocampal changes and impaired cognition, and inhibiting activation, but not infiltration, mitigated their pro-aging effects. Conversely, targeting aged circulating CD8+ T cells restored youthful signatures and rescued cognition. Mechanistically, we identified granzyme K (GZMK) as a secreted pro-aging CD8+ T cell-derived factor in plasma, and GZMK inhibition rescued cognition in aged animals. Together, our data identified activated aged CD8+ T cell-derived circulating factors as potential therapeutic targets to rescue cognition in old age.
    Keywords:  brain aging; cognitive decline; hippocampus; immune aging; parabiosis; peripheral immune brain cross-talk; rejuvenation
    DOI:  https://doi.org/10.1016/j.immuni.2026.04.014
  5. Cancer Res. 2026 May 12.
      T-cell exhaustion in the tumor microenvironment undermines anti-tumor immunity and limits immunotherapy efficacy. Further defining the metabolic triggers of this dysfunctional state could provide therapeutic targets for circumventing immunosuppression. Here we identified soluble uric acid (UA)-an abundant purine metabolite frequently elevated in cancer patients-as a metabolic checkpoint that drives exhaustion of CD8⁺ T cells and immune evasion in colorectal cancer (CRC). In hyperuricemic mouse models, elevated UA accelerated tumor progression in immunocompetent hosts, but not T-cell-deficient ones, by functionally exhausting tumor-infiltrating CD8⁺ T cells. Mechanistically, UA directly bound the kinase scaffold KSR1 and hyperactivated MEK-ERK signaling, leading to chronic MAPK stimulation that upregulated inhibitory receptors, including PD-1, Tim-3, on CD8⁺ T cells and blunted their cytotoxic function. Genetic disruption of this UA-KSR1-MAPK axis via Tim-3 knockout or Ksr1 knockdown restored T-cell effector activity and tumor control. Notably, pharmacological UA depletion with the clinical xanthine oxidase inhibitor febuxostat reinvigorated CD8⁺ T cells, slowing tumor growth and markedly enhancing the efficacy of both chemotherapy and adoptive T cell therapy in vivo. These findings establish soluble UA as a metabolic immune checkpoint that subverts anti-tumor T-cell immunity. Targeting UA metabolism may offer a strategy to overcome immune resistance and improve the efficacy of cancer immunotherapies.
    DOI:  https://doi.org/10.1158/0008-5472.CAN-25-3911
  6. J Cell Mol Med. 2026 May;30(9): e71164
      The Src-like adaptor 2 (SLA2) functions as a negative regulator of T cell receptor signalling. However, its involvement in the tumour microenvironment (TME) of gastric cancer (GC) remains unexplored. In this study, we found that SLA2 expression was significantly elevated in GC tissues, and a high level of SLA2 was associated with poor prognosis in GC patients. Bioinformatics analyses revealed a close association between SLA2 and TME in GC. Single-cell RNA sequencing analysis indicated that SLA2 was significantly enriched in CD8+ T cells in GC tissues. Functional validation demonstrated that SLA2 overexpression contributed to the exhaustion of CD8+ T cells by suppressing their proliferation, upregulating the expression of exhaustion markers, reducing the secretion of effector cytokines (IFN-γ and TNF-α) and impairing cytotoxic function. SLA2 knockdown in in vitro-generated exhausted CD8 T cells significantly alleviated T cell exhaustion. Mechanistically, we found that inverse promoter methylation and active histone marks (H3K27ac, H3K4me3 and H3K4me1) may regulate SLA2 expression. Our findings suggest that SLA2 may modulate the TME and promote immune evasion via CD8+ T cell exhaustion in GC.
    Keywords:  CD8+ T cells; SLA2; gastric cancer; immune evasion; tumour microenvironment
    DOI:  https://doi.org/10.1111/jcmm.71164
  7. Rinsho Ketsueki. 2026 ;67(4): 335-341
      Adoptive transfer of chimeric antigen receptor (CAR)-engineered T cells has been successfully established in B-cell malignancies and multiple myeloma. The fitness of infused CAR-T cells is closely associated with durable clinical responses. Terminal differentiation, which compromises long-term persistence, and exhaustion, which dampens effector function, are major drivers of T-cell dysfunction. Recent studies have demonstrated that genetic engineering approaches that modulate gene expression and epigenetic programs can counteract these mechanisms and enhance T-cell function. In addition, strategies to augment T-cell function through artificial cytokine signaling have been extensively investigated. This review discusses these recent advancements.
    Keywords:  Chimeric antigen receptor; Cytokine signaling; Epigenetics; T-cell fitness
    DOI:  https://doi.org/10.11406/rinketsu.67.335
  8. Nat Immunol. 2026 May 12.
      T cell exhaustion represents a critical target for immunotherapy in cancer. Nevertheless, T cells exhibit diminished responsiveness to immune checkpoint inhibitors once they transition to a terminally exhausted state. Here we used an epigenetic drug screen and identified bromodomain and extra-terminal motif inhibitors (BETis) as enhancers of effector functions in primary exhausted T cells (TEX) from malignant pleural effusions in patients with lung cancer. Transcriptomics, metabolomics and ATAC-seq analyses revealed that BETis reinvigorate TEX cells by activating the polyamine biosynthesis pathway, expanding intracellular polyamine pools and altering chromatin accessibility. Genetic and pharmacological inhibition of ornithine decarboxylase (ODC1), a key enzyme in this pathway, abolished BETi-mediated immunopotentiation. Single-cell RNA-seq demonstrated that BETis reduced terminal TEX while promoting progenitor TEX through activation of the MYC-ODC axis. BETi treatment or adoptive transfer of BETi-treated T cells suppressed malignant pleural effusion formation in a syngeneic lung cancer model. These findings highlight an epigenetic-metabolic approach to enhance TEX plasticity and offer insights for novel cancer immunotherapies.
    DOI:  https://doi.org/10.1038/s41590-026-02515-5
  9. Eur J Immunol. 2026 May;56(5): e70202
      Human CD8+ T cells undergo significant metabolic and transcriptional shifts during activation and differentiation. The orphan nuclear receptor Nur77 plays a role in modulating these processes and has been linked to T cell dysfunction. However, few studies have addressed its role in the memory potential and functionality of human CD8+ T cells. Here, we evaluated the expression of Nur77 in human CD8+ T cells, focusing on its relationship with their differentiation profile and functionality. Our findings indicate that Nur77 is associated with an early-differentiated, T cell factor 1+ (TCF-1+) memory-like phenotype in both total and virus-specific human CD8+ T cells across contexts of acute resolved or chronic viral infection and vaccination. Nur77 expression was associated with cytokine polyfunctionality and increased proliferative capacity in long-lived antigen-responsive cells. Moreover, the modulation of Nur77 activity in vitro enhanced the functionality of chronic human immunodeficiency virus (HIV) and hepatitis B virus (HBV)-specific CD8+ T cells. These results suggest that Nur77 is associated with polyfunctional properties in virus-specific CD8+ T cell responses in humans. In addition, this study provides insights into novel strategies for enhancing CD8+ T cell functionality in settings of chronic antigen stimulation.
    Keywords:  CD8+ T cells; Nur77; human; memory; polyfunctionality; proliferation; stem‐like
    DOI:  https://doi.org/10.1002/eji.70202
  10. Mol Cancer. 2026 May 11.
      As the core effector cells of the adaptive immune system, T cells play a crucial role in the body's anti-tumor immune responses. However, various toxic factors widely present in the tumor microenvironment (TME), including metabolic abnormalities, mitochondrial transfer phenomena, and diverse toxic mediators, can exert "poisoning" effects on T cells through complex and diverse mechanisms, consequently leading to T cell intoxication. In this state, their roles within the TME undergo profound transformation, with exhaustion being the most typical manifestation. This exhaustion is characterized by loss of anti-tumor function, metabolic dysfunction, and high expression of inhibitory receptors, thereby exacerbating tumor progression. However, studies have revealed that as tumor poisoning intensifies, certain specialized T cell subsets not only exhibit functional impairment but can also actively promote tumor progression through mechanisms such as cytokine secretion and recruitment of tumor-associated cells-a phenomenon defined as T cell betrayal. This review comprehensively and systematically summarizes the patterns of T cell fate transformation during tumor development and provides an in-depth analysis of the essential characteristics of T cell intoxication and betrayal, including their phenotypic features, functional alterations, and their impact on the tumor microenvironment and immunotherapy. Particular emphasis is placed on analyzing the molecular integrative mechanisms by which tumor cells and other cells in the microenvironment poison T cells and induce their intoxication or betrayal through multiple pathways. Furthermore, this review systematically examines therapeutic strategies for reversing T cell betrayal phenomena, including metabolic intervention and microenvironmental modulation, as well as optimization strategies for conventional immunotherapies. This review further explores future directions for achieving a systematic and holistic understanding of the T cell "intoxication-betrayal" framework and examines the potential application value of cutting-edge technologies in this field, aiming to provide novel insights for tumor immunotherapy.
    Keywords:  Cancer; Immune evasion; Oncogenesis; T cell dysfunction; Tumor microenvironment
    DOI:  https://doi.org/10.1186/s12943-026-02669-8
  11. Blood. 2026 May 12. pii: blood.2025030873. [Epub ahead of print]
      T cell exhaustion has been shown to be a key resistance mechanism to efficacy of T cell engagers (TCE) in multiple myeloma (MM). Mezigdomide, a potent cereblon E3 ligase modulator that targets IKZF1 and IKZF3 simultaneously for proteasomal degradation, has been shown to modulate T cell activity in MM patients. We explored the possibility that targeting IKZF1/IKZF3 could address T cell exhaustion and restore functionality. We conducted extensive transcriptomic and epigenetic profiling on ex vivo generated exhausted T cells, using their autologous activated T cells as a comparison. Our study reveals that IKZF1 and IKZF3 are critical regulators contributing to the development and maintenance of T cell exhaustion. They regulate transcription by directly binding to promoters and enhancers, both proximal and distal, thereby altering transcriptional potential. Increased IKZF1 binding to exhaustion genes after multiple T cell stimulations results in enhancement of transcription, while binding to cytokine genes results in transcription repression. Mezigdomide treatment in exhausted T cells results in decreased expression of exhaustion-related markers, increased proinflammatory cytokine expression, and enhanced target cell killing with Alnuctamab, a B-cell maturation antigen (BCMA) targeting TCE. This study provides crucial mechanistic insights into the roles of IKZF1/IKZF3 in T cell exhaustion, supporting the rationale for combining mezigdomide with TCEs to enhance therapeutic outcomes in MM.
    DOI:  https://doi.org/10.1182/blood.2025030873
  12. Int J Mol Sci. 2026 Apr 24. pii: 3795. [Epub ahead of print]27(9):
      Vitiligo is characterized by epidermal melanocyte destruction, with autoreactive CD8+ T cells playing a central pathogenic role, yet the mechanisms driving their hyperactivation remain unclear. Lactate has emerged as a key immunometabolite that functions as both a signaling molecule and an epigenetic modulator via protein lactylation. Nevertheless, the role of lactate in vitiligo pathogenesis has not been explored. Here, we report that serum lactate levels are significantly elevated in vitiligo patients and correlate positively with disease activity. In a mouse model, lactate administration accelerated vitiligo progression, accompanied by increased CD8+ T cell infiltration and melanocyte destruction in lesional skin. In vitro, lactate enhanced CD8+ T cell effector molecule expression (granzyme B, perforin, IFN-γ, CD107a) and cytotoxic function. Mechanistically, lactate increased global protein lactylation in CD8+ T cells, with marked enrichment at histone H3 lysine 9 (H3K9). H3K9 lactylation (H3K9la) was associated with enhanced chromatin accessibility and transcriptional activation of effector genes, as revealed by RNA sequencing and CUT&Tag analyses. Pharmacological inhibition of lactate production or lactylation abrogated these effects. Collectively, our findings identify lactate as a critical driver of CD8+ T cell pathogenicity in vitiligo through H3K9la-mediated epigenetic reprogramming, highlighting lactate metabolism and lactylation as potential therapeutic targets.
    Keywords:  CD8+ T cells; autoimmunity; lactylation; vitiligo
    DOI:  https://doi.org/10.3390/ijms27093795
  13. Transl Oncol. 2026 May 15. pii: S1936-5233(26)00146-4. [Epub ahead of print]69 102809
       BACKGROUND: CD8⁺ T cell exhaustion is a defining feature of the immunosuppressive TME in ccRCC.
    METHODS: We employed a multi-omics driven pipeline to nominate Nicotinamide N-methyltransferase (NNMT) as a high-confidence therapeutic target in ccRCC. This computational prediction was validated through bulk RNA-seq, single-cell RNA sequencing, and spatial transcriptomics to delineate NNMT-associated molecular and cellular programs. While the discovery phase highlighted endothelial-specific NNMT overexpression, we further validated the functional consequences of NNMT modulation using Caki-1 and A498 cell lines to model the downstream signaling cascades. Functional assays assessed impacts on proliferation, apoptosis, cytokine secretion (IL-6, IL-1β, TNF-α), and TGF-β pathway activity. Immune infiltration and T cell exhaustion signatures were evaluated across TCGA cohorts.
    RESULTS: Multi-omics profiling revealed that NNMT is specifically overexpressed in tumor-associated endothelial cells enriched for active TGF-β signaling and inflammatory cues. High NNMT expression strongly correlated with CD8⁺ T cell exhaustion, elevated apoptotic signaling, and immunosuppressive cytokine production. In functional validation, NNMT knockdown suppressed TGF-β activity, reduced pro-inflammatory cytokines, and restored CD8⁺ T cell infiltration and effector function. Mechanistically, NNMT loss shifted the BAX/Bcl-2 ratio toward apoptosis and increased cleaved caspase-3. Spatial transcriptomics confirmed that NNMT⁺ endothelial cells form an immunosuppressive niche in direct contact with exhausted T cells. We also found that I-BET-762, I-BET-151, PFI-1, and BMS-387032 can target and inhibit NNMT to reduce CD8⁺ T cell exhaustion.
    CONCLUSION: We establish NNMT as a central metabolic-immune hub that orchestrates TGF-β-mediated CD8⁺ T cell dysfunction and endothelial reprogramming in ccRCC.
    Keywords:  CD8⁺ T cell exhaustion; Clear cell renal cell carcinoma; Multi-Omics; NNMT; TGF-β signaling
    DOI:  https://doi.org/10.1016/j.tranon.2026.102809
  14. J Neuroinflammation. 2026 May 09.
      Although the lung-brain axis has emerged as a potential regulator of central nervous system (CNS) autoimmunity, the cellular and molecular mechanisms by which the lung microenvironment influences pathogenesis of multiple sclerosis (MS) remain unclear. Here, using experimental autoimmune encephalomyelitis (EAE), a murine model of MS, we found a marked expansion of effector CD4⁺ T cells in the lungs of EAE mice. The EAE lung microenvironment promoted metabolic reprogramming in CD4⁺ T cells, characterized by enhanced fatty acid uptake and upregulation of carnitine transporters. Metabolomic profiling further demonstrated enrichment of carnitine-related metabolites in the EAE lungs, with a strong correlation between metabolic profiles in the lungs and brains, suggesting coordinated metabolic remodeling along the lung-brain axis. Mechanistically, the EAE lung microenvironment significantly enhanced effector CD4⁺ T cell differentiation in vitro through a β-oxidation-dependent pathway. Importantly, pharmacological inhibition of β-oxidation in the lungs significantly attenuated EAE severity, reduced CD4⁺ T cell infiltration into the CNS, and impaired effector CD4⁺ T cell differentiation in the lungs. Collectively, these findings demonstrate that β-oxidation-mediated differentiation of effector CD4⁺ T cells in the lung exacerbates neuroinflammation, highlighting the lung-brain axis as a potential therapeutic target for MS.
    Keywords:  Effector CD4+ T cells; Experimental autoimmune encephalomyelitis; Lipid metabolism; Lung-brain axis; Multiple sclerosis
    DOI:  https://doi.org/10.1186/s12974-026-03865-5
  15. bioRxiv. 2026 Feb 27. pii: 2026.02.24.707057. [Epub ahead of print]
      Immune responses evolve across time and tissues through coordinated programs of proliferation, differentiation, and migration, yet most single-cell measurements capture only static molecular snapshots. As a result, reconstructing how immune cells transition between alternative fates remains challenging, particularly for CD8 T cells, whose differentiation is highly dynamic and shaped by rapid expansion, contraction, and tissue trafficking. Here, we introduce an optimal transport-based fate mapping framework that reconstructs continuous CD8 T cell trajectories across time and tissues. Applied to longitudinal single-cell RNA-seq data from CD8 T cells responding to acute viral infection in mice, this approach accurately recapitulates population dynamics and resolves coherent effector and memory T cell differentiation trajectories. Extending the model to multiple tissues, we identify and experimentally validate temporally distinct waves of migration into the small intestine that give rise to divergent tissue-resident memory (T rm ) fates, long-lived T cells crucial in immunosurveillance. By integrating optimal transport inference with time-resolved in vivo labeling, we demonstrate that CD52 marks recent tissue entrants and distinguishes them from T rm precursors. Finally, trajectory-guided analysis of transcription factor regulons reveals both shared and context-specific gene regulatory programs and identifies AP4 as a key regulator of circulating versus tissue-resident specification. These results establish optimal transport as a principled framework for reconstructing immune cell fate dynamics and provide a quantitative map of early events governing antiviral CD8 T cell differentiation across tissues.
    DOI:  https://doi.org/10.64898/2026.02.24.707057
  16. Small. 2026 May 13. e13605
      CD4+ T cells play a pivotal role in anti-tumor immunity by assisting CD8+ T cells in eliminating MHC I+ tumor cells and promoting immune responses against MHC-deficient tumors through myeloid-cell recruitment. Extracellular vesicles (EVs) are increasingly recognized as important mediators of intercellular immune communication; however, how CD4+ T helper (Th)-derived EVs modulate tumor immune cells, including CD8+ T cells and eosinophils, to orchestrate anti-tumor responses remains poorly understood. Here, we show that immune checkpoint molecules, including PD-1 and TIM-3, and the cytokine IL-5 are enriched on CD4+ Th cell microvilli and EVs. Activated CD4+ Th cells released both exosomes and ectosomes, which cooperatively suppressed tumor progression through two complementary mechanisms. First, CD4+ Th-derived exosomes and ectosomes displayed immune checkpoint receptors such as PD-1 and TIM-3 on their surface, thereby intercepting tumor-derived inhibitory signals, reversing T cell exhaustion, and enhancing cytotoxic T cell activity. Second, CD4+ Th-derived EVs carried IL-5 and other effector molecules that promoted JAK-STAT signaling, eosinophil recruitment to tumor sites, and eosinophil-mediated tumor cell killing through degranulation. Moreover, CD4+ Th-derived EVs remodeled the tumor microenvironment by enhancing CD8+ T cell and eosinophil infiltration and activation, suggesting their potential role in immune regulation and cancer therapy.
    Keywords:  CD4+ Th cells; cancer immunotherapy; eosinophils; extracellular vesicles
    DOI:  https://doi.org/10.1002/smll.202513605
  17. iScience. 2026 Jun 19. 29(6): 115788
      Developing strategies to precisely modulate the tumor immune microenvironment (TME) is crucial for advancing immunotherapy. Here, we reported that 980-nm pulsed photobiomodulation (PBM) inhibits early tumor growth by locally reinvigorating antitumor immunity, without direct cancer cell cytotoxicity. In syngeneic LLC and MC38 models, daily PBM delayed tumor growth and conferred durable protection upon rechallenge without systemic toxicity, while efficacy was dependent on CD8+ T cells. Single-cell RNA sequencing and flow cytometry revealed that PBM directly alleviates CD8+ T cell exhaustion and enhances their cytotoxic function in a regulatory T cell (Treg)-independent manner, with immunomodulatory effects restricted to irradiated tumor sites, whereas contralateral, untreated lesions remained unaffected, confirming a localized mode of immune modulation. PBM failed against pigmented B16 melanoma, likely due to melanin-mediated light absorption. Collectively, 980-nm pulsed PBM is a localized photo-immunomodulatory strategy that reinvigorates CD8+ T cells, holding potential as a safe adjunct to existing immunotherapies.
    Keywords:  cancer; immunology; photomedicine
    DOI:  https://doi.org/10.1016/j.isci.2026.115788
  18. Methods Mol Biol. 2026 ;2997 151-161
      T-cell exhaustion is characterized by low proliferative capacity, suppressed effector function, and the persistent expression of co-suppressive receptors such as PD-1 and TIM-3. Chronic activation of T cells, as seen in chronic viral infections or cancer, leads to T-cell exhaustion. In addition, T-cell exhaustion is a major obstacle to the clinical application of T-cell-dependent bispecific antibodies (TDBs). On the other hand, blocking the co-suppressive receptors has improved T-cell function, highlighting the importance of recovery from T-cell exhaustion to enhance therapeutic efficacy. Ongoing research focuses on recovering from exhausted T cells using genetic engineering, particularly in CAR-T cell therapy. Although mouse models infected with LCMV are widely used to generate exhausted T cells, this method raises concerns about animal welfare. We established a method using magnetic beads to induce T-cell exhaustion in vitro, simulating the immune state caused by chronic activation. Moreover, this in vitro exhaustion-induction method is applicable to the evaluation of TDB functional activity and the examination of the T-cell manipulation methods. Collectively, the current in vitro T-cell exhaustion assay system will be helpful for the development of TDBs to overcome T-cell exhaustion.
    Keywords:  Cell killing assay; Chronic activation; In vitro exhaustion induction; Magnetic beads; T-cell exhaustion; T-cell-dependent bispecific antibodies
    DOI:  https://doi.org/10.1007/978-1-0716-5037-0_11
  19. Front Immunol. 2026 ;17 1775981
      Hematologic disorders, including malignant and autoimmune conditions, present persistent clinical challenges characterized by relapse, treatment resistance, and profound immune dysregulation. While conventional immunotherapies have advanced, their efficacy is frequently limited by HLA downregulation and effector T cell exhaustion. In this context, γδ T cells offer a promising therapeutic alternative. Recognizing antigens independently of MHC restriction, γδ T cells possess intrinsic tissue-homing capabilities and exhibit dual cytotoxic and immunoregulatory functions. These properties make them highly suitable candidates for allogeneic, "off-the-shelf" cellular therapies where αβ T cells face alloreactive limitations. This review systematically synthesizes the immunobiology of γδ T cells, exploring the functional heterogeneity of specific subsets and their regulation within the tumor microenvironment (TME). We critically evaluate recent preclinical and clinical evidence supporting adoptive transfer, CAR-γδ T strategies, and combination regimens across acute leukemias, lymphomas, multiple myeloma, and immune cytopenias. Furthermore, we address critical translational barriers-including in vivo persistence, subset exhaustion, and manufacturing variability-and discuss rational engineering strategies, metabolic preconditioning, and epigenetic modulation as solutions. Ultimately, advancing γδ T cell therapies requires overcoming these hurdles to transition them effectively from the bench to mainstream clinical practice.
    Keywords:  CAR-γδ T cell therapy; cytokine plasticity; hematologic malignancies; translational barriers; γδ T cells
    DOI:  https://doi.org/10.3389/fimmu.2026.1775981
  20. bioRxiv. 2026 Feb 27. pii: 2026.02.25.708034. [Epub ahead of print]
      Many pathogenic human infections enter the host via a mucosal surface. These nonlymphoid tissues are abundantly populated by polyclonal memory CD8 T cells that persist following infections to protect the host in the event of repeat exposure. Memory T cells can be triggered via T cell receptor (TCR) interaction with their cognate antigen upon re-infection to exert effector functions, including cytotoxicity and cytokine production, and assist in pathogen elimination. Alternatively, some T cells are 'bystander activated' by cytokines without antigenic signal. This layered approach boosts efccient pathogen clearance but also poses a threat to host tissues if this response is not properly controlled. Here we investigate the regulatory mechanisms modulating the tissue memory CD8 T cell response upon recall, leveraging mouse models to distinguish antigen-driven versus cytokine-activated memory tissue CD8 T cell immunity. We cnd that regulatory T cells (Treg) play a role in restricting cytotoxic and bystander activity in mucosal T cells without compromising the antigen-driven protective memory CD8 T cell response. Critically, Treg provide extrinsic regulation of tissue CD8 T cell cytotoxicity through restriction of available IL-2 and IL-15 trans-presentation. Our cndings help to decne the extrinsic environmental and cellular cues in mucosal tissues that direct tissue memory CD8 T cell cytotoxicity.
    DOI:  https://doi.org/10.64898/2026.02.25.708034
  21. Cell Commun Signal. 2026 May 14.
      Pancreatic Ductal Adenocarcinoma (PDA) remains one of the deadliest malignancies, characterized by the paucity of effective therapies and an inferior prognosis, driven by an immunosuppressive tumour microenvironment (TME), marked by defective dendritic cells (DCs) function, exclusion or dysfunction of effector T cells, and dominance of suppressive stromal and myeloid cells. p21-activated kinases (PAKs) play crucial roles in PDA tumorigenesis. Emerging evidence highlights PAKs as pivotal regulators of PDA immune evasion by inhibiting the recruitment and function of DCs and T cells, integrating oncogenic, metabolic, and cytoskeletal signaling to shape the tumour immune microenvironment. Although immune checkpoint inhibitors (ICIs), DC cancer vaccines, and T cell-based immunotherapies have demonstrated safety and immunogenicity, the clinical efficacy remains uncertain in PDA. It has been shown in preclinical models that inhibition of PAKs reduces tumour growth, enhances DCs and T cells infiltration, restores DC and cytotoxic T cell function, and improves the efficacy of chemotherapy and ICIs. In this review, we summarized current evidence on the roles of PAKs in DC and T cell dysfunction in PDA and discussed their impact on PDA immunotherapy. The combination of PAK inhibition with immunotherapies may present promising regimens to enhance immune responsiveness and clinical outcomes of PDA patients.
    Keywords:  Dendritic cells; PAKs; Pancreatic cancer; T cells
    DOI:  https://doi.org/10.1186/s12964-026-02923-y
  22. Curr Opin HIV AIDS. 2026 May 15.
       PURPOSE OF REVIEW: HIV integration into BACH2 is significantly enriched in people living with HIV (PLWH), but not in vitro . Specifically, HIV integration sites are enriched in the same orientation and upstream of BACH2 translation. HIV drives high levels of BACH2 expression through HIV-to- BACH2 splicing. BACH2, a transcription repressor that competes with AP-1 binding, is an effector-to-memory switch that restrains effector function, drives T cell stemness, and promotes long-lived memory.
    RECENT FINDINGS: Retroviral infection mouse model containing retroviral splice sites recapitulated the orientation- and site-dependent enrichment of integration into BACH2 , revealing in-vivo selection pressure favoring BACH2 expression. Two back-to-back BACH2 studies revealed that BACH2 promotes HIV persistence. High BACH2 activity in the gut tissue resident memory CD4 + T cells (T RM ) drives long-lived persistence of HIV-infected cells in the gut, while high BACH2 activity in the gut HIV-specific CD8 + T RM restrains effector function. Higher BACH2 activity in tissues than blood drives distinct mechanisms of HIV persistence in the gut versus blood. Finally, three back-to-back BACH2 studies revealed how druggable finetuning of BACH2 promotes chimeric antigen receptor (CAR)-T cell persistence and efficacy.
    SUMMARY: BACH2 promotes the persistence of both HIV and CAR-T cells by driving T cell stemness and long-lived memory.
    Keywords:  BACH2; CAR-T cell immunotherapy; HIV cure; HIV integration site; single-cell multiomics
    DOI:  https://doi.org/10.1097/COH.0000000000001041
  23. Immunity. 2026 May 12. pii: S1074-7613(26)00169-X. [Epub ahead of print]59(5): 1168-1170
      CD8+ T cells responding to chronic infections are functionally and spatially heterogeneous. In this issue of Immunity, Shen et al. and Geng et al. demonstrate that the transcription factors KLF2 and KLF3 have integrated but opposing roles in regulating tissue residency and terminal exhaustion.
    DOI:  https://doi.org/10.1016/j.immuni.2026.04.007
  24. Immune Netw. 2026 Apr;26(2): e15
      Immunosenescence refers to the age-associated decline in immune competence, driven, in part, by the senescence-associated secretory phenotype (SASP), which maintains chronic low-grade inflammation ("inflammaging"). Aging alters both innate and adaptive immunity, marked by impaired phagocytosis, antigen presentation, and cytotoxicity in macrophages, dendritic cells, neutrophils, and NK cells, as well as dysfunctional B-cell subsets, thymic involution, reduced TCR diversity, and accumulation of senescent CD4+CD28- and CD8+CD57+KLRG1+ T cells. Within tumors, these alterations promote immune evasion through SASP-derived IL-6 and TGF-β, expand myeloid-derived suppressor cells, and favor angiogenic and immunosuppressive macrophage states. Cytotoxic lymphocyte and NK-cell dysfunction further weakens antitumor immunity and limits the responses to checkpoint inhibitors and chimeric Ag receptor T-cell therapy in older patients. In this review, we summarize the cellular and molecular mechanisms underlying immune cell aging and outline how immunosenescence programs reshape the tumor microenvironment and influence cancer immunotherapy outcomes.
    Keywords:  CAR T-cell; Cancer immunotherapy; Immunosenescence; Inflammaging; Tumor microenvironment
    DOI:  https://doi.org/10.4110/in.2026.26.e15
  25. Nat Commun. 2026 May 15.
      Microsatellite-stable/proficient mismatch repair (MSS/pMMR) colorectal cancer (CRC) is characterized by a cold tumor microenvironment, with limited CD8⁺ T cell infiltration and poor responsiveness to immune checkpoint inhibitors (ICIs). Here, using an in vivo CRISPR/Cas9 screen in a CMT93 cell-derived murine tumor model, we identify Arid3b as a key negative regulator of CD8⁺ T cell infiltration and antitumor activity. Genetic ablation of Arid3b in CD8⁺ T cells significantly enhances their intratumoral accumulation and promotes robust tumor control. Mechanistically, Arid3b deficiency upregulates Runx3, driving a tissue-resident memory-like phenotype and effector function. Notably, the benefits conferred by Arid3b deficiency are abrogated upon Runx3 deletion, indicating a RUNX3-dependent mechanism. Together, targeting ARID3B could offer a promising strategy to reshape the tumor microenvironment and sensitize MSS CRC to immunotherapy.
    DOI:  https://doi.org/10.1038/s41467-026-73241-7
  26. Front Immunol. 2026 ;17 1770102
      This scoping review highlights the critical role of microRNAs (miRNAs) in mediating the bidirectional crosstalk between CD8+ T cells and tumor cells within the immunosuppressive tumor microenvironment (TME). Specific miRNAs (e.g., miR-155, miR-340-5p) orchestrate CD8+ T cell function by fine-tuning immune checkpoints (PD-1/PD-L1), metabolic reprogramming, and epigenetic states. Conversely, CD8+ T cells influence tumor behavior via exosomal miRNA transfer (e.g., miR-765). Our analysis reveals both pan-cancer mechanisms, such as PD-1/PD-L1 regulation, and tissue-specific miRNA functions (e.g., miR-143 in melanoma). To overcome translational challenges like off-target effects, innovative delivery strategies using lipid nanoparticles and engineered exosomes are being developed. This review provides a mechanistic framework for miRNA-mediated interactions, offers clinical insights for novel combination therapies, and assesses future directions, thereby advancing the development of precision immunotherapies.
    Keywords:  CD8+T cell; cancer; cellular pathway; immunology; microRNA
    DOI:  https://doi.org/10.3389/fimmu.2026.1770102
  27. iScience. 2026 May 15. 29(5): 115744
      In multiple sclerosis (MS), T cells could contribute to disease in their attempt to control the Epstein-Barr virus (EBV). Here, we compared the presence of HLA-B7 (higher MS risk) or HLA-A2 (lower MS risk) and investigated the effector phenotype of EBV epitope-specific CD8+ T cells in MS using spectral flow cytometry. In contrast to HLA-A2, HLA-B7-restricted CD8+ T cells recognized few EBV epitopes. These HLA-B7-restricted EBV-specific CD8+ T cells expressed CNS residency markers and were most abundant in postmortem CNS compartments of an HLA-A2+B7+ MS donor. HLA-B7-restricted EBV-specific CD8+ T cells displayed a more exhausted phenotype (PD-1+CD244+CD160+KLRG1+TIGIT+). In line with these findings, anti-EBNA1 IgG levels were elevated in patients with MS carrying HLA-B7 but lacking HLA-A2. These data support a model in which the confined response against EBV generates circulating HLA-B7-restricted CD8+ T cells less able to control EBV and more prone to infiltrate the CNS.
    Keywords:  immunology
    DOI:  https://doi.org/10.1016/j.isci.2026.115744
  28. Clin Rev Allergy Immunol. 2026 May 11. pii: 43. [Epub ahead of print]69(1):
      Systemic lupus erythematosus (SLE) is a heterogeneous autoimmune disease characterized by chronic immune activation, relapsing-remitting clinical progression, and progressive multi-organ damage. In addition to the classical characteristics of autoantibodies and immune complexes, emerging evidence highlights T-cell immunosenescence as a key factor in SLE pathogenesis. In this review, we elucidate the phenotypic and molecular landscapes of immunosenescent T cells in SLE, highlighting the core cellular programs that reshape their functional identity, including cell cycle arrest, dysregulated apoptosis, oxidative stress and DNA damage, mitochondrial reprogramming, and senescence-associated secretory phenotype (SASP). By integrating these mechanistic insights, we propose an immunosenescence-inflammation vicious cycle in SLE, focusing on how an expanded pool of immunosenescent T cells emerges and how mitochondrial dysfunction sustains this loop. In parallel, we elucidate the molecular crosstalk between inflammatory signaling pathways of SLE and immunosenescence programs. Moreover, evidence linking T-cell immunosenescence to SLE complications, including cardiovascular and metabolic comorbidities, as well as other systemic manifestations, is summarized. Finally, we outline therapeutic perspectives that target T-cell immunosenescence. Specifically, we discuss senolytics (for instance, dasatinib, quercetin, and fisetin) designed to selectively eliminate senescent cells, and senomorphics (for instance, rapamycin and Janus kinase inhibitors) designed to suppress the SASP and improve mitochondrial function, while discussing practical considerations for clinical translation. These advances underscore the potential of biomarker-guided patient stratification for future precision interventions in SLE.
    Keywords:  Immunosenescence; Inflammation; SLE; Senolytics; Senomorphics; T cell
    DOI:  https://doi.org/10.1007/s12016-026-09164-4
  29. Cytokine. 2026 May 08. pii: S1043-4666(26)00060-8. [Epub ahead of print]203 157165
       BACKGROUND: Childhood neuropsychiatric systemic lupus erythematosus (cNPSLE) represents one of the most severe complications of systemic lupus erythematosus. Aberrant CD8+ T cell activation and hyperactivated IFN-I signaling contribute to cNPSLE immunopathogenesis. IFI27, a key IFN-I-stimulated gene, has not been functionally characterized in cNPSLE.
    METHODS: The scRNA-seq data from cNPSLE patients were analyzed to characterize immune cell heterogeneity and interactions using cell clustering, differential gene screening, GO enrichment, and CellChat analysis. NPSLE mouse models were established to evaluate cognitive function, disease activities, and neuropathological changes. IFN-I pathway activation, IFI27 expression, and CD8+ T cell quantity and activation were assessed using WB, qRT-PCR, and flow cytometry, respectively. The co-culture of CD8+ T cells with BV2 microglia was established to elucidate the regulatory effect of CD8+ T cell-derived IFN-I signaling on microglial function via morphological observation, ELISA, and Transwell assays.
    RESULTS: Increased proportions of IFI27+CD8+ T cells were observed in the peripheral blood of cNPSLE patients. This subset highly expressed IFI27 and was markedly enriched for the IFN-I pathway, potentially promoting neuroinflammation. Animal experiments confirmed that IFI27 silencing ameliorated cognitive impairment, reduced autoantibody levels, and suppressed IFN-I pathway activation and effector subset differentiation in CD8+ T cells in NPSLE mice. These protective effects were reversed by IFN-I agonist treatment. Mechanistically, IFI27 activated the IFN-I pathway in CD8+ T cells, promoting microglial activation, phagocytic function, and pro-inflammatory cytokine release.
    CONCLUSION: IFI27 accelerates cNPSLE progression by stimulating the IFN-I pathway in CD8+ T cells, driving their differentiation into cytotoxic phenotypes, and enhancing microglial activation and neuroinflammation.
    Keywords:  CD8(+) T cells; Childhood neuropsychiatric systemic lupus erythematosus; IFI27; IFN-I signaling pathway; Microglia
    DOI:  https://doi.org/10.1016/j.cyto.2026.157165