bims-imseme 2025-04-20 papers

bims-imseme

Biomed News

on Immunosenescence and T cell metabolism

Issue of 2025–04–20
nineteen papers selected by
Pierpaolo Ginefra, Ludwig Institute for Cancer Research

Metabolic Reprogramming of Glycolysis, Lipids, and Amino Acids in Tumors: Impact on CD8+ T Cell Function and Targeted Therapeutic Strategies.
T cell-based cancer immunotherapy: opportunities and challenges.
Metabolic Profiling of Activated T Lymphocytes Using Single-Cell Energetic Metabolism by Profiling Translation Inhibition (SCENITH).
Measuring Mitochondrial Function of Naïve and Effector CD8 T Cells.
Deubiquitinase USP24 activated by IL-6/STAT3 enhances PD-1 protein stability and suppresses T cell antitumor response.
Metabolic Dialogue Shapes Immune Response in the Tumor Microenvironment.
Memory-promoting function of miR-379-5p attenuates CD8+ T cell exhaustion by targeting immune checkpoints.
Metabolic Screening of T Lymphocytes During Activation via SEAHORSE Extracellular Flux (XF) Analysis.
T-cell Senescence in the Tumor Microenvironment.
Imaging BiTE-Mediated Activation of Primary Human CD8+ T Cells.
FTO controls CD8+ T cell survival and effector response by modulating m6A methylation of Fas.
CD4+ T-cell help delivery to monocyte-derived dendritic cells promotes effector differentiation of helper and cytotoxic T cells.
Cytokine-mediated regulation of immune cell metabolic pathways in the tumor microenvironment.
Stem-like CD8+ T cells preserve HBV-specific responses in HBV/HIV co-infection.
Two chemotherapeutic agents expand stem-like CD62L+CD8+ T cells in antitumor immune responses.
Overcoming extracellular vesicle-mediated fratricide improves CAR T cell treatment against solid tumors.
ScRNA-Seq reveals T cell immunity in COVID-19 patients and implications for immunotherapy.
Using Seahorse Technology as an Efficient Way of Verifying T Cell Stimulation.
Changing landscape of hematopoietic and mesenchymal cells and their interactions during aging and in age-related skeletal pathologies.

FASEB J. 2025 Apr 30. 39(8): e70520

Metabolic Reprogramming of Glycolysis, Lipids, and Amino Acids in Tumors: Impact on CD8+ T Cell Function and Targeted Therapeutic Strategies.

Panping Liang, Zedong Li, Zhengwen Chen, Zehua Chen, Tao Jin, Fengjun He, Xiaolong Chen, Hongfeng Gou, Kun Yang.

  Tumor cells undergo metabolic reprogramming to support their rapid proliferation and to adapt to the challenges of the tumor microenvironment (TME). This involves significant changes in glycolysis, lipid, and amino acid metabolism, which not only promote tumor survival but also impact CD8+ T cells within the TME. This review examines how these metabolic alterations affect CD8+ T cell function, particularly through competition for energy resources and microenvironmental changes. For instance, aerobic glycolysis in tumor cells depletes glucose and leads to lactate accumulation, both of which suppress CD8+ T cell activity. Additionally, changes in lipid metabolism affect the composition of cell membranes and disrupt signal transduction, impairing T cell function. Amino acid reprogramming, such as increased consumption of glutamine and arginine by tumor cells, further hinders the activity and proliferation of CD8+ T cells. We also explore therapeutic strategies that target these metabolic pathways in tumor cells, such as inhibitors of glycolysis and fatty acid synthesis, which may enhance the antitumor activity of CD8+ T cells. These approaches show promise in improving both T cell function and the effectiveness of immune checkpoint blockade therapies. By investigating the link between tumor metabolism and CD8+ T cell dysfunction, this review highlights mechanisms of tumor immune evasion. This understanding can guide the development of novel immunotherapies aimed at enhancing T cell function within the TME.

Keywords:  CD8+ T cell; fatty acids; glutamine; glycolysis; metabolic reprogramming

DOI:  https://doi.org/10.1096/fj.202403019R
Sci Bull (Beijing). 2025 Mar 31. pii: S2095-9273(25)00337-8. [Epub ahead of print]

T cell-based cancer immunotherapy: opportunities and challenges.

Kaili Ma, Yingxi Xu, Hongcheng Cheng, Ke Tang, Jingwei Ma, Bo Huang.

  T cells play a central role in the cancer immunity cycle. The therapeutic outcomes of T cell-based intervention strategies are determined by multiple factors at various stages of the cycle. Here, we summarize and discuss recent advances in T cell immunotherapy and potential barriers to it within the framework of the cancer immunity cycle, including T-cell recognition of tumor antigens for activation, T cell trafficking and infiltration into tumors, and killing of target cells. Moreover, we discuss the key factors influencing T cell differentiation and functionality, including TCR stimulation, costimulatory signals, cytokines, metabolic reprogramming, and mechanistic forces. We also highlight the key transcription factors dictating T cell differentiation and discuss how metabolic circuits and specific metabolites shape the epigenetic program of tumor-infiltrating T cells. We conclude that a better understanding of T cell fate decision will help design novel strategies to overcome the barriers to effective cancer immunity.

Keywords:  CD8(+) T cell; Cancer immunotherapy; Differentiation; Epigenetic regulation; Metabolism

DOI:  https://doi.org/10.1016/j.scib.2025.03.054
Methods Mol Biol. 2025 ;2904 259-271

Metabolic Profiling of Activated T Lymphocytes Using Single-Cell Energetic Metabolism by Profiling Translation Inhibition (SCENITH).

Katrin Sinning, Sophia M Hochrein, Gabriela F Gubert, Martin Vaeth.

  Metabolic reprogramming is increasingly recognized as a fundamental aspect of T cell activation, influencing the differentiation, proliferation, and effector functions of lymphocytes. Measuring and screening the metabolic states of activated T cells provide insights into the dynamic interplay between cellular metabolism and immune function. In the following chapter, we provide a simple protocol based on the publication of Argüello et al. [1] to analyze the metabolic state of activated T cells at the single-cell level using standard flow cytometry.

Keywords:  FACS; Glycolysis; Metabolism; Oxidative phosphorylation; SCENITH; T cells

DOI:  https://doi.org/10.1007/978-1-0716-4414-0_18
J Vis Exp. 2025 Mar 28.

Measuring Mitochondrial Function of Naïve and Effector CD8 T Cells.

Jacqueline A Turner, Elizabeth Katsnelson, Raul M Torres.

Understanding how immunometabolism impacts the function, differentiation, and fate of lymphocytes has garnered significant interest and attention. Lymphocyte biology has been explored using bioenergetic analysis and has now become a critically import tool in the field. Thus, we sought to optimize a bioenergetic analysis assay that can be adapted with pretreatments and acute injection for receptor stimulations. Here, we evaluated CD8 T cell ex vivo metabolism using the Cell Mito Stress Test to assess rates of oxygen consumption and extracellular acidification in naïve and effector CD8 T cells. Antigen-specific effector CD8 T cells were derived via ex vivo stimulation, and naïve CD8 T cells harvested from splenocytes and isolated with magnetic bead column separation. Pretreatments are performed in microplates and we detail how to prepare sensor cartridges. We show how injection ports can loaded with drugs to indirectly measure metabolic capacities and with metabolic modulators, this protocol can be used to study specific enzyme activity. T-cell receptor stimulations can be studied in real time with acute injection and stimulation with anti-CD3/CD28 using the injection ports. Instrument analyzers are used for measurements and data collection and data visualization is done with software programs to interpret cellular metabolism. This strategy produces an extensive amount of data on immune cell biology and mitochondrial bioenergetics allowing researchers to customize the protocol in numerous ways to explore CD8 T cell metabolism.

DOI: https://doi.org/10.3791/65642
Sci Adv. 2025 Apr 18. 11(16): eadt4258

Deubiquitinase USP24 activated by IL-6/STAT3 enhances PD-1 protein stability and suppresses T cell antitumor response.

Hung-Chia Hsieh, Ming-Jer Young, Kuan-Yu Chen, Wu-Chou Su, Chien-Chung Lin, Yi-Ting Yen, Jan-Jong Hung, Yi-Ching Wang.

Persisting programmed cell death-1 (PD-1) signaling impairs T cell effector function, which is highly associated with T cell exhaustion and immunotherapy failure. However, the mechanism responsible for PD-1 deubiquitination and T cell dysfunction remains unclear. Here, we show that ubiquitin-specific peptidase 24 (USP24) promotes PD-1 protein stability by removing K48-linked polyubiquitin. Increased interleukin-6 level transcriptionally activates the USP24 expression, which leads to PD-1 stabilization. Furthermore, USP24 deficiency reduces PD-1 levels in CD8+ T cells and attenuates EgfrL858R-driven lung tumorigenesis in Usp24C1695A catalytic deficient mice. Targeting PD-1 stability with the USP24-specific inhibitor USP24-i-101 boosts cytotoxic T cell activity, restrains lung tumor growth, and achieves superior therapeutic effects when combined with anti-CTLA4 immunotherapy. Clinically, patients with lung cancer exhibiting high USP24 expression in tumor-infiltrating CD8+ T cells display exhausted features and show unfavorable responses to immunotherapy. Our findings dissect the mechanism for regulating enhanced PD-1 stability in tumor-infiltrating CD8+ T cells and reveal USP24 as a potential target of antitumor immunotherapy.

DOI: https://doi.org/10.1126/sciadv.adt4258
Eur J Immunol. 2025 Apr;55(4): e202451102

Metabolic Dialogue Shapes Immune Response in the Tumor Microenvironment.

Fengxia Gao, Rushil Shah, Gang Xin, Ruoning Wang.

The fate of immune cells is fundamentally linked to their metabolic program, which is also influenced by the metabolic landscape of their environment. The tumor microenvironment represents a unique system for intercellular metabolic interactions, where tumor-derived metabolites suppress effector CD8+ T cells and promote tumor-promoting macrophages, reinforcing an immune-suppressive niche. This review will discuss recent advancements in metabolism research, exploring the interplay between various metabolites and their effects on immune cells within the tumor microenvironment.

DOI: https://doi.org/10.1002/eji.202451102
J Immunother Cancer. 2025 Apr 12. pii: e010363. [Epub ahead of print]13(4):

Memory-promoting function of miR-379-5p attenuates CD8+ T cell exhaustion by targeting immune checkpoints.

You-Zhe Lin, Chia-Hsin Liu, Wan-Rong Wu, Ting-Yi Liao, Chuan-Chun Lee, Hong-Wei Li, Feng-Chi Chung, Yi-Chun Shen, Guan-Yu Zhuo, Liang-Chih Liu, Wei-Chung Cheng, Shao-Chun Wang.

   BACKGROUND: MicroRNAs (miRNAs) are epigenetic regulators of T cell maturation and exhaustion. However, the mechanisms by which miRNAs influence T cell function in tumor environments remain unclear. This study focuses on miR-379-5p, which counteracts T cell exhaustion and enhances antitumor responses.
METHODS: Native CD8+ T cells were isolated from the blood of healthy donors and subjected to chronic stimulation to induce exhaustion. RNA sequencing and miRNA sequencing were performed to identify differentially expressed miRNAs. These miRNAs underwent bioinformatics analyses, including DESeq enrichment, immune cell infiltration assessment, and patient prognostic outcomes in The Cancer Genome Atlas data sets to assess their potential involvement in T cell exhaustion and antitumor immunity. The biological functions of miRNA on T cell differentiation, cytotoxic killing, and immune checkpoint regulation were investigated using in vitro assays, OT-I B16F10-OVA models, and patient-derived tumor organoids.
RESULTS: MiR-379-5p is downregulated in exhausted T cells and negatively associated with exhausted tumor-infiltrating lymphocytes in advanced tumors. It correlates positively with better survival outcomes in breast cancer, cervical cancer and melanoma. In CD8+ T cells, miR-379-5p reduces the expression of immune checkpoint proteins T cell immunoglobulin and mucin-domain containing-3 (TIM3) and T cell immunoreceptor with Ig and ITIM domains (TIGIT) by targeting their 3' untranslated region. Overexpression of miR-379-5p in CD8+ T cell promotes differentiation into memory-like T effector cells and enhances cytotoxic killing of cancer cells. The transcription factor nuclear receptor subfamily 4 group A member 1 (NR4A1) with increased expression in exhausted T cells and negatively regulates miR-379, restoring immune checkpoint expression and suppressing cancer-killing ability. In contrast, OT-I T cells expressing ectopic miR-379-5p show increased cytotoxicity against B16F10-OVA tumors in mice. Autologous T cells isolated from patients with breast cancer transduced with miR-379-5p significantly improve killing of tumor organoids derived from the same patients.
CONCLUSIONS: MiR-379-5p acts as an epigenetic tumor suppressor by enhancing CD8+ T cell effector functions and suppressing T cell exhaustion. MiR-379-5p could represent a novel marker and strategy for cancer immunotherapy, offering promising avenues for enhancing antitumor immune responses.

Keywords:  Breast Cancer; Immunotherapy; T cell; co-inhibitory molecule

DOI:  https://doi.org/10.1136/jitc-2024-010363
Methods Mol Biol. 2025 ;2904 243-258

Metabolic Screening of T Lymphocytes During Activation via SEAHORSE Extracellular Flux (XF) Analysis.

Gabriela F Gubert, Sophia M Hochrein, Katrin Sinning, Martin Vaeth.

  Upon activation, T cells undergo a profound reconfiguration of their metabolic profile, transitioning from a quiescent to a metabolically active state characterized by an increase in both aerobic glycolysis and mitochondrial respiration. Seahorse extracellular flux (XF) analysis is a powerful method for measuring the changes in fundamental metabolic pathways in real-time, including aerobic glycolysis and mitochondrial respiration of live T cells. This method allows a precise determination of mitochondrial performance and lactate secretion, which is measured as oxygen consumption rate (OCR) and glycolytic proton efflux rate (ECAR), respectively. By dynamically monitoring these metabolic changes, Seahorse XF analysis provides comprehensive insights into the metabolic dynamics of (activated) T cells across diverse experimental conditions or treatments.

Keywords:  Bioenergetic profile; ECAR; Glycolysis; Metabolic remodeling; Metabolism; Mitochondrial respiration; OCR; Seahorse; T cell activation

DOI:  https://doi.org/10.1007/978-1-0716-4414-0_17
Cancer Immunol Res. 2025 Apr 15. OF1-OF15

T-cell Senescence in the Tumor Microenvironment.

Lihaoyun Huang, Cangang Zhang, Aimin Jiang, Anqi Lin, Lingxuan Zhu, Weiming Mou, Dongqiang Zeng, Zaoqu Liu, Bufu Tang, Jian Zhang, Quan Cheng, Kai Miao, Ting Wei, Peng Luo.

T-cell senescence occurs in the tumor microenvironment (TME) and influences cancer outcomes, as well as the effectiveness of immunotherapies. The TME triggers this T-cell senescence via multiple pathways, including persistent stimulation with tumor-associated antigens, altered metabolic pathways, and activation of chronic inflammatory responses. Senescent T cells exhibit characteristics such as genomic instability, loss of protein homeostasis, metabolic dysregulation, and epigenetic alterations. Direct cross-talk between senescent T cells and other immune cells further exacerbates the immunosuppressive TME. This immune-tumor cell interaction within the TME contributes to impaired tumor antigen recognition and surveillance by T cells. The presence of senescent T cells is often associated with poor prognosis and reduced efficacy of immunotherapies; thus, targeting the tumor-promoting mechanisms of T-cell senescence may provide novel insights into improving tumor immunotherapy and patient outcomes. This review explores the contributors to tumor-derived T-cell senescence, the link between T-cell senescence and tumor prognosis, and the potential for targeting T-cell senescence to enhance tumor immunotherapy.

DOI: https://doi.org/10.1158/2326-6066.CIR-24-0894
Methods Mol Biol. 2025 ;2904 159-177

Imaging BiTE-Mediated Activation of Primary Human CD8+ T Cells.

Kai J Winterberg, Constantin Möller, Lea I Schwarze, Sophia Cichutek, Julia Hambach, Andreas H Guse, Boris Fehse, Björn-Philipp Diercks, Kristoffer Riecken.

  CD8+ T cells are a vital branch of the adaptive immune response. They are necessary for an effective antiviral and anticancer immunity, which is mediated through their cytotoxic effector functions. CD8+ T cell activation, proliferation, and effector functions are dependent on a complex network of Ca2+ signalling pathways involving both Ca2+ release and Ca2+ entry. Dysregulation of intracellular Ca2+ signalling pathways has been linked to immunodeficiencies including severe combined immunodeficiency syndrome (SCID), highlighting the need to study both Ca2+ dynamics and cytotoxic effector function in patient-derived CD8+ T cells. The following protocol describes a workflow for the isolation of primary human CD8+ T cells and their activation using bispecific T cell engagers (BiTEs). This allows for a simultaneous assessment of both Ca2+ dynamics and cytotoxicity through a target cell line presenting an epitope recognized by the BiTE.

Keywords:  Bispecific T cell engager; CD8+ T cell; Ca2+ signaling; Live-cell imaging

DOI:  https://doi.org/10.1007/978-1-0716-4414-0_12
Cell Death Dis. 2025 Apr 15. 16(1): 301

FTO controls CD8+ T cell survival and effector response by modulating m6A methylation of Fas.

Lina Sun, Tianzhe Zhang, Yao Ge, Zhihong Yao, Yanhong Su, Qianhao Wang, Yang Chen, Boxiao He, Renyi Ding, Cangang Zhang, Linbo Lan, Ruonan Liu, Huanxin Ping, Dan Zhang, Lin Shi, Xiaobo Zhou, Xiaoxuan Jia, Chenming Sun, Lingli Liang, Lianjun Zhang, Baojun Zhang.

Functional CD8+ T cell immunity is essential for immune surveillance and host defense against infection and tumors. Epigenetic mechanisms, particularly RNA modification, in controlling CD8+ T cell immune response is not fully elucidated. Here, by T cell-specific deletion of fat mass and obesity-associated protein (FTO), a critical N6-methyladenosine (m6A) demethylase, we revealed that FTO was indispensable for adequate CD8+ T cell immune response and protective function. FTO ablation led to considerable cell death in activated CD8+ T cells, which was attributed to cell apoptosis. MeRIP-seq analysis revealed an increase in m6A methylation on Fas mRNA in FTO-deficient CD8+ T cells. The loss of FTO promoted Fas expression via enhancing the Fas mRNA stability, which depended on the m6A reader insulin-like growth factor-2 mRNA-biding proteins 3 (IGF2BP3). Mutation of the Fas m6A sites or knockdown IGF2BP3 could normalize the upregulated Fas expression and apoptosis levels caused by FTO ablation in CD8+ T cells. Our findings delineate a novel epigenetic regulatory mechanism of FTO-mediated m6A modification in supporting CD8+ T cell survival and effector responses, providing new insights into understanding the post-transcriptional regulation in CD8+ T cell immunological functions and the potential therapeutic intervention.

DOI: https://doi.org/10.1038/s41419-025-07606-z
Immunol Lett. 2025 Apr 14. pii: S0165-2478(25)00055-0. [Epub ahead of print] 107022

CD4+ T-cell help delivery to monocyte-derived dendritic cells promotes effector differentiation of helper and cytotoxic T cells.

Douwe M T Bosma, Julia Busselaar, Mo D Staal, Elselien Frijlink, Matthias Mack, Fiamma Salerno, Jannie Borst.

  Delivery of CD4+ T-cell help optimizes CD8+ T-cell effector and memory responses via CD40-mediated licensing of conventional dendritic cells (DCs). Using comparative vaccination settings that prime CD8+ T cells in presence or absence of CD4+ T-cell help, we observed that CD4+ T-cell activation promoted influx of monocytes into the vaccine-draining lymph nodes (dLNs), where they differentiated into monocyte-derived (Mo)DCs, as defined by the most recent standards. Abrogation of these responses by CCR2-targeted depletion indicated that monocyte-derived cells in the dLN promoted T-helper 1 (Th1) type effector differentiation of CD4+ T cells, as well as clonal expansion and effector differentiation of CD8+ T cells. Monocyte-derived cells in dLNs upregulated CD40, CD80 and PD-L1 as a result of CD4+ T-cell help. The response of monocyte-derived cells to CD4+ T-cell help was independent of natural killer (NK) cells and proceeded via CD40 ligand (L)-CD40 interactions and IFNγ signaling. Our data argue for a scenario wherein activated CD4+ T cells in dLNs crosstalk via CD40L and IFNγ signals to monocytes, promoting their local differentiation into MoDCs. This event enhances formation of CD4+ Th1 and CD8+ cytotoxic effector T cell pool, most likely by virtue of their improved costimulatory status and cytokine production.

Keywords:  CD4(+) T-cell help; MoDC; T-cell priming; monocyte; vaccination

DOI:  https://doi.org/10.1016/j.imlet.2025.107022
Naunyn Schmiedebergs Arch Pharmacol. 2025 Apr 12.

Cytokine-mediated regulation of immune cell metabolic pathways in the tumor microenvironment.

Alireza Soleimani Mamalo, Mohammadreza Pashaei, Mohammad Valilo, Masoud Ojarudi.

  Cancer, an important global health problem, is defined by aberrant cell proliferation and continues to be the main cause of death globally. The tumor microenvironment (TME) plays an essential role in the development of cancer, resistance to therapy, and regulation of the immune response. Some immune cells in the TME, like T cells, B cells, macrophages, dendritic cells, and natural killer cells, can either stop or help tumor growth, depending on how metabolic and cytokine changes happen. Cytokines function as essential signaling molecules that modulate immune cell metabolism, altering their functionality. This review focuses on how cytokine-mediated metabolic reprogramming affects the activity of immune cells inside the TME, which can either make the immune response stronger or weaker. New ways of treating cancer that focus on metabolic pathways and cytokine signaling, such as using IL (Interleukin) - 15, IL- 10, and IL- 4, show promise in boosting immune cell activity and making cancer treatments more effective. Finding these pathways could lead to new ways to treat cancer with immunotherapy that focus on metabolic competition and immune resistance in the TME.

Keywords:  Cytokine; Immune cells; Metabolic reprogramming; Tumor microenvironment

DOI:  https://doi.org/10.1007/s00210-025-04133-8
medRxiv. 2025 Apr 03. pii: 2025.03.30.25324898. [Epub ahead of print]

Stem-like CD8+ T cells preserve HBV-specific responses in HBV/HIV co-infection.

Jay Preechanukul, Aljawharah Alrubayyi, Bo Sun, Edward Arbe-Barnes, Jonida Kokici, Frances Gorou, Sarun Prasitdumrong, Kelly A S da Costa, Natasha Fisher-Pearson, Noshin Hussain, Stephanie Kucykowicz, Indrajit Ghosh, Fiona Burns, Sabine Kinloch, Pedro Simoes, Sanjay Bhagani, Patrick T F Kennedy, Mala K Maini, Rachael Bashford-Rogers, Upkar S Gill, Dimitra Peppa.

Objective: Chronic HBV infection disproportionately affects people living with HIV, who are often excluded from functional cure studies. This study investigates CD8 + T cell profiles in HBV mono-infection versus HBV/HIV co-infection, examining the impact of long-term therapy on virus-specific responses with the goal of informing therapeutic strategies for immune restoration.
Design: We analysed CD8 + T cell responses in 61 participants (HBV n=20, HBV/HIV n=20, HIV n=21), on suppressive antiviral therapy. We assessed transcriptomic and proteomic profiles, focusing on exhaustion markers alongside virus-specific functional capabilities.
Results: Transcriptomic analysis revealed a distinct signature in co-infection, with upregulation of genes associated with TCR signaling, inhibitory pathways and progenitor-exhausted markers ( XCL2, TCF7, PDCD1, IL7R ). This gene profile scored highly for a precursor exhausted (Tpex) CD8+ T cell signature, reflecting a "stemness" programme that maintains plasticity despite chronic antigen exposure. Proteomic analysis confirmed higher frequencies of precursor exhausted TCF-1 + CD127 + PD-1 + CD8 + T cells in co-infection, while HBV mono-infection showed predominance of terminally exhausted Tox high TCF-1 - CD127 - cells. These differences correlated with more robust, polyfunctional HBV-specific responses in co-infection against surface and core antigens. Lower HBsAg levels and longer treatment duration in co-infection associated positively with Tpex populations and functional responses and inversely with terminal exhaustion.
Conclusion: Our findings demonstrate that individuals with well-controlled HBV/HIV co-infection maintain more robust CD8 + T cell responses with preserved stem-like properties supporting ongoing antiviral function. These results underscore the benefits of early antiretroviral intervention and the need for tailored immune-modulatory therapies to restore antiviral functionality in these diverse patient populations.
WHAT IS ALREADY KNOWN ON THIS TOPIC: Chronic hepatitis B virus (HBV) infection is marked by a progressive dysfunction of CD8⁺ T cells, which are crucial for antiviral responses. Traditionally these responses were thought to be more severely impacted in people with HBV/HIV co-infection.
WHAT THIS STUDY ADDS: Our study provides new insights into the heterogeneous functional profiles of HBV-specific CD8⁺ T cells in people with HBV and HBV/HIV co-infection in the current antiretroviral therapy (ART) era.People living with HBV/HIV co-infection suppressed on antivirals have a higher prevalence of precursor exhausted CD8⁺ T cells (Tpex), alongside more effective antiviral responses when compared to those with HBV mono-infection.Our data demonstrate intrinsic differences in T cell profiles, revealing a paradoxical increase in terminally exhausted CD8⁺ T cells in people with HBV mono-infection.
HOW THIS STUDY MIGHT AFFECT RESEARCH PRACTICE OR POLICY: By providing a clearer understanding of CD8⁺ T cell dynamics in HBV mono-infection and HBV/HIV co-infection, our findings could inform the design of tailored immunotherapies aimed at revitalising antiviral responses.Furthermore, this research may influence practices regarding clinical management emphasising the need for early intervention strategies and individualised approaches tailored to T cell profiles rather than solely based on infection status.

DOI: https://doi.org/10.1101/2025.03.30.25324898
Front Immunol. 2025 ;16 1533857

Two chemotherapeutic agents expand stem-like CD62L+CD8+ T cells in antitumor immune responses.

Xiaokang Ruan, Linwei Wu, Zijian Tang, Yao Li, Jin Wang, Haolin Jiang, Li Zhang, Shengjia Wang, Zhaoqiang Chen, Chenlei Yuan, Yujian Xia, Yan Pan, Jianling Gao, Xin Zhao.

   Introduction: Recent findings reveal that the precursors of exhausted CD8+ T (CD8+ Tpex) cells possess stem-like signatures in tumor immunity, which originate from tumor draining lymph node (TdLN)-derived tumor-specific memory (CD8+ TTSM) cells. Both of these T subsets can be collectively referred to as stem-like CD8+ T cells, which demonstrate robust self-renewal ability and can proliferate and differentiate into transitory effector-like exhausted T cells (Texint). There are reports that chemotherapeutic drugs can promote the antitumor immune responses of patients by increasing the number of CD8+ T cells; however, whether chemotherapeutic drugs increase these two stem-like CD8+ T cells remain further exploration.
Methods: Tpex cell-associated subpopulations in human colorectal tumors were analyzed by using single-cell sequencing data. CT26 and B16 tumor models of wild type and Eomes conditional knockout mice were constructed, and the changes of TTSM, Tpex and Tex subsets in mice were dissected by flow cytometry after treatment with decitabine (DAC), doxorubicin (DOX) and 5-Fluorouracil (5-FU).
Results: In this study, we demonstrated that DAC and 5-FU expanded CD8+ TTSM cells in TdLNs. At the same time, we validated that DAC and 5-FU substantially promoted the expansion of CD62L+CD8+ Tpex cells and subsequently increased effector function of CX3CR1+ CD8+ Texint cells. In addition, the conditional knockout of transcription factor Eomes in CD8+ T cells partially eliminated DAC-amplified CD62L+ CD8+ Tpex cells, but had no effect on such CD8+ T subset expanded by 5-FU.
Conclusion: The present study demonstrated that both DAC and 5-FU promoted the differentiation of stem-like CD8+ TTSM cells in TdLNs and significantly enhanced the differentiation and expansion of stem-like CD62L+ CD8+ Tpex and CX3CR1+ Texint cells in tumor microenvironment. The knockout of Eomes partially influenced the role of DAC in promoting the differentiation and expansion of stem-like CD8+ T cells.

Keywords:  CD62L+ CD8+ Tpex cells; CD8+ TTSM cells; Eomes; antitumor immune responses; chemotherapeutic agents

DOI:  https://doi.org/10.3389/fimmu.2025.1533857
Nat Cancer. 2025 Apr 15.

Overcoming extracellular vesicle-mediated fratricide improves CAR T cell treatment against solid tumors.

Wenqun Zhong, Zhiyuan Qin, Ziyan Yu, Jingbo Yang, Dongdong Yan, Nils W Engel, Neil C Sheppard, Yi Fan, Ravi Radhakrishnan, Xiaowei Xu, Leyuan Ma, Serge Y Fuchs, Carl H June, Wei Guo.

The efficacy of chimeric antigen receptor (CAR) T cells against solid tumors is limited. The molecular mechanisms underlying CAR T cell resistance are yet to be elucidated and new strategies need to be developed to improve treatment outcomes. Here we report that solid tumors respond to CAR T cells by upregulating the secretion of small extracellular vesicles carrying tumor antigens, which are horizontally transferred to CAR T cells, leading to antigen recognition and CAR T cell fratricide. Engineered CAR T cells armored with Serpin B9, a major granzyme B inhibitor, show decreased fratricide and increased vitality, tumor infiltration, and antitumor activity in female mice. Moreover, Serpin B9-armored CAR T cells show higher efficacy than parental CAR T cells in treating solid tumors when combined with the anti-programmed death 1 antibody. Our study demonstrates a mechanism that limits CAR T cell function and suggests an improved strategy in tumor treatment.

DOI: https://doi.org/10.1038/s43018-025-00949-8
Int Immunopharmacol. 2025 Apr 14. pii: S1567-5769(25)00653-8. [Epub ahead of print]155 114663

ScRNA-Seq reveals T cell immunity in COVID-19 patients and implications for immunotherapy.

Zhihong Yao, Zhao Feng, Hui Zhang, Baojun Zhang.

  SARS-CoV-2, the virus causing COVID-19, poses significant health threats due to its high transmissibility and potential for severe respiratory complications. T cells, central to adaptive immunity, also interact with innate immunity, playing a pivotal role in coordinating defenses and eliminating infected cells. Single-cell RNA sequencing (scRNA-seq) has provided more subtle heterogeneity, rare subpopulations, or new subpopulations that are at the district differentiation stage or with specific function. Thus, elucidating how T cell heterogeneity impacts COVID-19 disease severity remains a critical question requiring comprehensive analysis. This review revealed the heterogeneity of the host T cells, including conventional T cells (CD8+, CD4+ T cells) and unconventional T cells, including natural killer T (NKT) cells, mucosal-associated invariant T (MAIT) and gamma-delta T (γδT) cells in COVID-19 patients with different clinical manifestations. Severe COVID-19 had marked lymphopenia, excessive activation, elevated exhaustion and reduced functional diversity of T cells. Pathogenic contributions arise from dysregulated cytotoxic T cells, Treg cells and unconventional T cells collectively driving systemic hyperinflammation and tissue injury. Current therapeutic strategies targeting T cells-such as enhancing virus-specific T cell responses, reverting T-cell exhaustion and alleviating inflammation-exhibit inconsistent efficacy, underscoring the need for combinatorial approaches. This review highlights how scRNA-seq deciphers T cell heterogeneity and dysfunction in COVID-19. By targeting T cell exhaustion, inflammation, and subset-specific deficits, these insights pave the way for therapies and vaccines.

Keywords:  COVID-19, ScRNA-seq; Immune response; Immunotherapy; SARS-CoV-2; T cells

DOI:  https://doi.org/10.1016/j.intimp.2025.114663
Methods Mol Biol. 2025 ;2904 219-242

Using Seahorse Technology as an Efficient Way of Verifying T Cell Stimulation.

Jonas Aakre Wik, Kristine Stromsnes, Bjørn Steen Skålhegg.

  Antibody-dependent stimulation is commonly used to activate, differentiate, and/or to expand T cells for downstream analysis and functions. Such stimulations are inherently connected to endogenous phosphorylation which is commonly assessed using various methods including immunoblotting. However, antibody-dependent stimulation of T cells is also inherently connected to changes in endogenous metabolic activity. We describe methods used to stimulate T cells using soluble and immobilized antibodies in conjunction with immunosuppressive cyclic AMP (cAMP). The stimulations were assessed by downstream phosphorylation using immunoblotting and metabolic changes using Seahorse technology. We use phosphorylation of ERK 1/2, extracellular acidification rate (ECAR) and oxygen consumption rate (OCR) as readouts to represent the activation state of T cells. We also describe how these methods can be used to assess inhibitory stimuli exemplified by the cAMP analogue 8-(4-Chlorophenylthio) adenosine 3',5'-cyclic monophosphate (8-CPT-cAMP), but only if 8-CPT-cAMP is added before anti-CD3. Together the methods described in this chapter provide a comprehensive guideline to isolate, stimulate, and assess T cell stimulation. Moreover, we demonstrate the Seahorse technology as a time and work-efficient way of assessing the effects of T cell stimulation in real time.

Keywords:  Cell signaling; Immunology; Metabolism; Seahorse technology; T cells; Western blot

DOI:  https://doi.org/10.1007/978-1-0716-4414-0_16
Mech Ageing Dev. 2025 Apr 10. pii: S0047-6374(25)00035-1. [Epub ahead of print] 112059

Changing landscape of hematopoietic and mesenchymal cells and their interactions during aging and in age-related skeletal pathologies.

Abhishek Chandra, Susan F Law, Robert J Pignolo.

  Aging profoundly impacts mesenchymal and hematopoietic lineage cells, including their progenitors-the skeletal stem cells (SSCs) and hematopoietic stem cells (HSCs), respectively. SSCs are crucial for skeletal development, homeostasis, and regeneration, maintaining bone integrity by differentiating into osteoblasts, adipocytes, and other lineages that contribute to the bone marrow (BM) microenvironment. Meanwhile, HSCs sustain hematopoiesis and immune function. With aging, SSCs and HSCs undergo significant functional decline, partly driven by cellular senescence-a hallmark of aging characterized by irreversible growth arrest, secretion of pro-inflammatory factors (senescence associated secretory phenotype, SASP), and impaired regenerative potential. In SSCs, senescence skews lineage commitment toward adipogenesis at the expense of osteogenesis, contributing to increased bone marrow adiposity (BMAd), reduced bone quality, and osteoporosis. Similarly, aged HSCs exhibit diminished self-renewal, biased differentiation, and heightened inflammation, compromising hematopoietic output and immune function. In this review, we examine the age-related cellular and molecular changes in SSCs and HSCs, their lineage decisions in the aging microenvironment, and the interplay between skeletal and hematopoietic compartments. We also discuss the role of senescence-driven alterations in BM homeostasis and how targeting cellular aging mechanisms may offer therapeutic strategies for mitigating age-related skeletal and hematopoietic decline.

Keywords:  Skeletal aging; bone marrow; cellular senescence; stem cells

DOI:  https://doi.org/10.1016/j.mad.2025.112059