Upon activation, T cells proliferate and differentiate into diverse populations, including highly differentiated effector and memory precursor subsets. Initial diversification is influenced by signals sensed during T cell priming within lymphoid tissues. However, the rules governing how cellular heterogeneity is spatially encoded in vivo remain unclear. Here, we show that immunization establishes concentration gradients of antigens and inflammation across interconnected chains of draining lymph nodes (IC-LNs). While T cells are activated at all sites, individual IC-LNs elicit divergent responses: proximal IC-LNs favor the generation of effector cells, whereas distal IC-LNs promote formation of central memory precursor cells. Although both proximal and distal sites contribute to anamnestic responses, T cells from proximal IC-LNs preferentially provide early effector responses at inflamed tissues. Conversely, T cells from distal IC-LNs demonstrate an enhanced capacity to generate long-lasting responses to chronic antigens in cancer settings, including after checkpoint blockade therapy. Therefore, formation of spatial gradients across lymphatic chains following vaccination regulates the magnitude, heterogeneity, and longevity of T cell responses.

Latent viral infections rely on a precise coordination of the immune response to control sporadic viral reactivation. CD8+ T cells play a crucial role in controlling viral latency by generating diverse memory responses in an epitope-specific manner. Among these distinct responses, conventional and inflationary memory responses have been described during herpesvirus infections. Using a newly generated TCR transgenic mouse strain, we investigated the transcriptomic and epigenetic remodeling of distinct epitope-specific CD8+ T cells during CMV infection across tissues at both population and single-cell levels. Our findings reveal that whereas the transcriptomic and epigenetic landscapes of conventional and inflationary memory responses diverge in the spleen and liver, these molecular programs converge in the salivary gland, a site of CMV persistence. Thus, we provide evidence that the dynamics of memory CD8+ T cell responses are distinct between tissues.

In central nervous system (CNS) diseases characterized by late-onset neurodegeneration, the interplay between innate and adaptive immune responses remains poorly understood. This knowledge gap is exacerbated by the prolonged protracted disease course as it complicates the delineation of brain-resident and infiltrating cells. Here, we conducted comprehensive profiling of innate and adaptive immune cells in a murine model of spastic paraplegia 15 (SPG15), a complicated form of hereditary spastic paraplegia. Using fate-mapping of bone marrow-derived cells, we identified microgliosis accompanied by infiltration and local expansion of T cells in the CNS of Spg15-/- mice. Single-cell analysis revealed an expansion of disease-associated microglia (DAM) and effector CD8+ T cells prior to neuronal loss. Analysis of potential cell-cell communication pathways suggested bidirectional interactions between DAM and effector CD8+ T cells, potentially contributing to disease progression in Spg15-/- mice. In summary, we identified a shift in microglial phenotypes associated with the recruitment and expansion of T cells as a new characteristic of Spg15-driven neuropathology.

The abundant cell components of the adaptive immune system called T lymphocytes (T cells) play important roles in mediating immune responses to eliminate the invaders and create the memory of the germs to form a new immunity for the next encounter. Among them, cytotoxic T cells expressing cell-surface CD8 are the most critical effector cells that directly eradicate the target infected cells by recognizing antigens presented by major histocompatibility complex class I molecules to protect our body from pathological threats. In the continuous evolution of immunotherapy, various CD8+ T cell-based therapeutic strategies have been developed based on the role and molecular concept of CD8+ T cells. The emergence of such remarkable therapies provides promising hope for multiple human disease treatments such as autoimmunity, infectious disease, cancer, and other non-infectious diseases. In this review, we aim to discuss the current knowledge on the utilization of CD8+ T cell-based immunotherapy for the treatment of various diseases, the molecular basis involved, and its limitations. Additionally, we summarize the recent advances in the use of CD8+ T cell-based immunotherapy and provide a comprehensive overview of CD8+ T cells, including their structure, underlying mechanism of function, and markers associated with CD8+ T cell exhaustion. Building upon these foundations, we delineate the advancement of CD8+ T cell-based immunotherapies with fundamental operating principles followed by research studies, and challenges, as well as illustrate human diseases involved in this development.

Hepatocellular carcinoma (HCC) is a global health concern because of its rising prevalence and high fatality rates. Conventional treatments for advanced HCC (aHCC) have limited success, emphasizing the need for novel treatment options. Radiotherapy (RT) treatments, such as stereotactic body radiation and proton therapy, improve local tumor management via precision targeting. Moreover, immune checkpoint inhibitors (ICIs) that target the programmed cell death protein 1(PD-1)/PD ligand 1 (PD-L1) and cytotoxic T lymphocyte associated protein 4 (CTLA-4) pathways have promise for systemic antitumor effectiveness. The combination of RT and ICIs takes advantage of their complementary mechanisms: RT kills immunogenic cells and controls the tumor microenvironment to increase antigen presentation, whereas ICIs enhance and maintain antitumor immune responses. This combination enhances tumor regression and immune response in aHCC, improving response rate and progression-free survival with manageable safety. The present review aimed to summarize the rationale for combining RT + ICIs in patients with aHCC and clinical outcomes, as well as ways to enhance this combination technique. The combination of these models is a promising technique for improving outcomes for patients with aHCC and warrants further investigation.

Immune checkpoint blockade (ICB) therapy represents a pivotal advancement in tumor immunotherapy by restoring the cytotoxic lymphocytes' anti-tumor activity through the modulation of immune checkpoint functions. Nevertheless, many patients experience suboptimal therapeutic outcomes, likely due to the immunosuppressive tumor microenvironment, drug resistance, and other factors. Single-cell RNA sequencing has assisted to precisely investigate the immune infiltration patterns before and after ICB treatment, enabling a high-resolution depiction of previously unrecognized functional interaction among immune checkpoints. This review addresses the heterogeneity between tumor microenvironments that respond to or resist ICB therapy, highlighting critical factors underlying the variation in immunotherapy efficacy and elucidating treatment failure. Furthermore, a comprehensive examination is provided of how specific ICBs modulate immune and tumor cells to achieve anti-tumor effects and generate treatment resistance, alongside a summary of emerging immune checkpoints identified as promising targets for cancer immunotherapy through single-cell RNA sequencing applications.

Hepatitis C virus (HCV) is a primary hepatotropic pathogen responsible for acute and chronic hepatitis C, however, it can also cause "occult" infection (OCI), defined as the presence of the virus' genetic material in hepatocytes and/or peripheral blood cells, but not in plasma/serum. Assessment of the sustained virologic response (SVR) after treatment with direct-acting antivirals (DAA) is based exclusively on HCV-RNA testing in plasma/serum, which may preclude the diagnosis of post-treatment OCI. Possible clinical consequences of OCI were described previously, but its occurrence after DAA-based antiviral treatment programs and determinants of the virus persistence are not fully elucidated. The aim of this study was to assess the incidence of post-treatment OCI after successful DAA-based treatment and to identify clinical and immunological factors associated with this phenomenon. In 97 patients treated with DAA, HCV-RNA was tested by RT-PCR in peripheral blood mononuclear cells (PBMC) at baseline (i.e., before the onset of treatment) and at the time of SVR assessment. Before treatment, HCV-RNA was detectable in all patients' PBMC. All subjects responded to therapy according to the clinical criteria, but 9 (9.3%) patients revealed the HCV-RNA in PBMC at SVR. In most of these cases, post-DAA OCI was related to switch of the dominant infecting genotype. Post-treatment OCI was characterized by significantly lower pre-treatment HCV viral load and lower expression of Tim-3 (T-cell immunoglobulin and mucin domain-containing protein 3) on CD8+ T-cells. Our results imply that post-treatment OCI may be related to lower pretreatment viral load as well as distinct pre-existing immune exhaustion status.

Cancer immunotherapy is transforming the treatment landscape of both hematological and solid cancers. Although T-cell-based adoptive cell transfer (ACT) therapies have demonstrated initial success, several recurrent obstacles limit their long-term anti-tumor efficacy, including: (1) lack of antigen specificity; (2) poor long-term survival of transplanted T cells in vivo; and (3) a hostile tumor microenvironment (TME). While numerous approaches have been explored to enhance the antigen specificity of Chimeric Antigen Receptor (CAR) T-cell therapies, the field still lacks an effective strategy to optimize the long-term retention and in vivo expansion of engrafted T cells within the TME-a critical factor for the durable efficacy of T-cell-based immunotherapies for both blood and solid cancers. Here, we hypothesize that the success of CAR T-cell therapy can be enhanced by targeting donor T cells' ability to compete with cancer cells for key nutrients, thereby overcoming T-cell exhaustion and sustaining durable anti-tumor function in the TME. To explore this hypothesis, we first provide a comprehensively review of the current understanding of the metabolic interactions (e.g., glucose metabolism) between T cells and tumor cells. To address the challenges, we propose an innovative strategy: utilizing nutrient gene therapy (genetic overexpression of glucose transporter 1, GLUT1) to fortify the metabolic competency of adoptive CAR T-cells, deprive tumors of critical metabolites and ATP, and disrupt the TME. Altogether, our proposed approach combining precision medicine (adoptive CAR T-cell therapy) with tumor metabolism-targeting strategies offers a promising and cost-effective solution to enhance the efficacy and durability of ACT therapies, ultimately improving outcomes for cancer patients.

Glucose metabolism is a critical regulator of T cell function, largely thought to support their activation and effector differentiation. Here, we investigate how individual glycolytic reactions determine the pathogenicity of T helper 17 (Th17) cells using Compass, an algorithm we previously developed for inferring metabolic states from single-cell RNA sequencing. Surprisingly, Compass predicted that the metabolic shunt between 3-phosphoglycerate (3PG) and 2-phosphoglycerate (2PG) is inversely correlated with pathogenicity in Th17 cells. Indeed, perturbation of phosphoglycerate mutase (PGAM), the enzyme catalyzing 3PG to 2PG conversion, induces a pathogenic gene expression program by suppressing a gene module associated with the least pathogenic state of Th17 cells. Finally, PGAM inhibition in Th17 cells exacerbates neuroinflammation in the adoptive transfer model of experimental autoimmune encephalomyelitis, consistently with PGAM promoting the non-pathogenic phenotype of Th17 cells. Overall, our study identifies PGAM, contrary to other glycolytic enzymes, as a negative regulator of pathogenic Th17 cell differentiation.

Multiple myeloma (MM) is a clonal proliferative disorder of plasma cells with limited curative options. Hepatitis B (HBV) and hepatitis C (HCV) viruses have been implicated in the development of various hematological malignancies, but their association with MM remains unclear. This systematic review and meta-analysis aimed to investigate the risk of MM in individuals with HBV and HCV infections.

A comprehensive literature search was conducted across PubMed, Scopus, Web of Science, Embase, and additional sources for cohort and case-control studies published between January 1990 and January 2025. The relative risk (RR) of developing MM in individuals with HBV and HCV infections was pooled using a random-effects model. Subgroup analyses were performed based on age, geographic region, and diagnostic method. The Newcastle-Ottawa Scale (NOS) was used to assess study quality. Statistical heterogeneity was evaluated using the I² statistic, and publication bias was assessed using Egger's test.

Seventeen studies, comprising 1 cohort and 16 case-control studies, were included. Nine studies examined the association between HBV and MM, yielding a pooled RR of 1.25 (95% CI: 0.99-1.58) with moderate heterogeneity (I² = 56.52%). Fifteen studies evaluated the association between HCV and MM, with a pooled RR of 1.84 (95% CI: 1.27-2.67), indicating a higher risk in HCV-infected individuals. Subgroup analysis revealed a stronger association in European populations for both HBV (RR: 1.67, 95% CI: 1.05-2.66) and HCV (RR: 2.27, 95% CI: 1.21-4.25). No significant publication bias was detected for either HBV or HCV analyses.

HBV and HCV infections are associated with an increased risk of developing multiple myeloma, with HCV demonstrating a stronger association. These findings highlight the importance of screening and monitoring patients with chronic hepatitis for potential hematological malignancies, especially in high-risk regions.

EMB-02 is a symmetric bispecific antibody targeting programmed cell death protein-1 and lymphocyte-activation gene 3 simultaneously. Here, we present the first-in-human study results of EMB-02 in patients with advanced solid tumors.

Patients were treated with intravenous infusions of EMB-02 at doses of 6-900 mg. The primary objective was to evaluate the safety and tolerability and to determine the maximum tolerated dose and/or recommended phase II dose(s). Secondary objectives included characterizing the pharmacokinetic (PK) profile, assessing preliminary antitumor activity and the immunogenicity.

A total of 47 patients were enrolled. All grade and grade 3/4 treatment-emergent and treatment related adverse events occurred in 97.9%, 48.9%, 68.1% and 12.8% patients, respectively. The objective response rate (ORR) was 6.4% and clinical benefit rate at 24 weeks (CBR-24) was 25.5% in overall population. The CBR-24 was 33.3% in checkpoint inhibitor (CPI)-naïve patients, and 15% in CPI-treated. No clear relationship was observed between the efficacy and PD-L1, LAG-3, or MHC II expression level. Doses 360 mg or higher resulted in sustained saturation of PD-1 receptors on circulating CD3 + T cells.

EMB-02 demonstrated a favorable safety profile and early efficacy signals in multiple solid tumors, warranting further development. (NCT04618393).

Transplant rejection remains a major challenge, driven primarily by the activation of alloreactive T cells. While enhancement of PD-L1 checkpoint molecules has exhibited potential in inhibiting T cell activity, its efficacy is often hindered by limited specificity and inadequate efficiency. Herein, a novel dual-phase immune modulation strategy is developed in which CTLA4-Ig and PD-L1 provide distinct, non-redundant inhibitory signals during the initial activation phase and the post-activation phase of T cells. PD-L1 is stably expressed on macrophages (sPD-L1 M) through lentiviral transduction, allowing them to leverage their chemotactic and antigen-presenting functions to target and deliver PD-L1 to transplant rejection sites. Notably, sPD-L1 M exhibited adaptive targeting capabilities, increasing their migration to grafts in response to heightened rejection. In an allograft skin model, the combined intravenous administration of sPD-L1 M and subcutaneous administration of CTLA4-Ig demonstrated synergistic efficacy, significantly suppressing alloreactive T cell activation, enhancing the recruitment of regulatory T cells (Tregs), downregulating pro-inflammatory cytokines, and prolonging allograft survival compared to either treatment alone. This study presents a promising strategy to effectively suppress T cell activity and prevent allogeneic immune responses without systemic immunosuppression.

With the increase in life expectancy, age-related conditions and diseases have become a widespread and relevant social burden. Among these, immunosenescence and cancer cachexia play a significant often intertwined role. Immunosenescence is the progressive aging decline of both the innate and adaptive immune systems leading to increased infection susceptibility, poor vaccination efficacy, autoimmune disease, and malignancies. Cancer cachexia affects elderly patients with cancer causing severe weight loss, muscle wasting, inflammation, and reduced response to therapies. Whereas the connections between immunosenescence and cancer cachexia have been raising attention, the molecular mechanisms still need to be completely elucidated. This review aims at providing the current knowledge about the interplay between immunosenescence, skeletal muscle, and cancer cachexia, analyzing the molecular pathways known so far to be involved. Finally, we highlight potential therapeutic strategies suited for elderly population aimed to block immunosenescence and to preserve muscle mass in cachexia, also presenting the analysis of the current state-of-the-art of related clinical trials.

Melanoma is the most dangerous skin cancer due to its difficulty in treatment, high recurrence rate and metastatic ability. As a vector for oncolytic viruses (OVs), vesicular stomatitis virus (VSV) has been shown to be effective against malignant melanoma. However, the glycoprotein G protein of VSV has potential neurotoxicity. It has been shown that replacing glycoprotein G with E3-E2-6K-E1 of chikungunya virus (CHIKV) reduces its neurotoxicity and targets gliomas. Therefore, the aim of this study was to investigate the oncolytic effect of recombinant VSV-CHIKV on melanoma and the underlying mechanism. In this study, we found that recombinant VSV-CHIKV triggered GSDMD-mediated melanoma cell pyroptosis. Importantly, the NLRP3/Caspase-1/GSDMD axis was activated after VSV-CHIKV infection in melanoma cell lines and in a xenograft mouse model. Inhibition of GSDMD blocked cell pyroptosis, antitumor immunity and the tumor response in response to VSV-CHIKV treatment, suggesting that VSV-CHIKV act through the GSDMD pathway. VSV-CHIKV-triggered GSDMD-mediated tumor pyroptosis recruited cytotoxic T lymphocytes (CTLs) into the tumor microenvironment, which was accompanied by the release of inflammatory mediators. This remodeled the tumor microenvironment and turned immunologically "cold" tumors into "hot" tumors, thereby sensitized these tumors to checkpoint blockade. Finally, the combination therapy of VSV-CHIKV and an immune checkpoint inhibitor (anti-PD-1) prolonged the survival of mice. In conclusion, the VSV-CHIKV strategy is an attractive biologic therapy against melanoma.

An unmet clinical need in chronic lymphocytic leukemia (CLL) is emerging due to the rapidly expanding group of patients with double refractory (Bruton's tyrosine kinase- and B-cell lymphoma 2-inhibitor) disease. So far, autologous T-cell-based therapies, including chimeric antigen receptor (CAR) T cells, have limited success in CLL, which has been attributed to an acquired CLL-mediated T-cell dysfunction and subset skewing toward effector cells at the expense of memory formation. T-cell responses rely on dynamic metabolic processes, particularly mitochondrial fitness. Although mitochondrial disruptions have been observed in solid tumor-infiltrating lymphocytes, their impact on T-cell immunity in lymphoproliferative disorders is unknown. Recent findings indicate that mitochondrial mass in CAR T cells correlates with CLL clinical outcomes. This prompted our investigation into the mitochondrial fitness in CLL T cells. Integrated metabolic and functional analyses revealed impaired, depolarized mitochondria across all T-cell subsets in untreated patients with CLL, leading to further ex vivo and in vivo mouse studies on the underlying signaling alterations. Multiomics profiling of transcriptome and epigenome revealed significant alterations in mitochondrial signaling, diminished adenosine monophosphate-activated protein kinase and autophagy activity, and upregulated glycolysis coupled with hyperactivation of Akt. Inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway during CLL T-cell culture induced metabolic reprogramming, enhancing mitochondrial activity, expression of peroxisome proliferator-activated receptor-gamma coactivator 1-alpha, and memory differentiation. Underscoring clinical relevance, supplementation with the PI3Kδ inhibitor idelalisib during CAR T-cell manufacturing improved persistence and long-term leukemia-free remissions in an immunocompetent murine model. Our study suggests that modulating the abnormal CLL T-cell metabolism can enhance the efficacy of autologous T-cell therapies.

NR2F6 is an orphan nuclear receptor with dual tumorigenic activity in the immune system and tumor cells, playing an essential role in tumor differentiation and immunity. This study aimed to investigate the expression level of NR2F6 in various tumors and its effect on neuroblastoma (NB).

We evaluated the role of NR2F6 in the genesis and development of 34 different tumors through multiple databases. In addition, we investigated the effects of NR2F6 expression levels on NB risk factors and prognosis using pathology sections and clinical data from primary retroperitoneal NB in children. The effects on cell proliferation, invasion, and migration were explored by knocking down NR2F6 expression in SK-N-BE(2) and SK-N-SH cells.

The findings showed that NR2F6 was significantly correlated with the prognosis of NB and was an important indicator suggesting disease regression. In addition, NR2F6 knockdown slowed down NB cells' proliferation, invasion, and migration ability in vitro.

Our results suggest that NR2F6 plays a crucial role in tumor-promoting effects and can be used as a potential prognostic marker for NB.

Chronic kidney disease (CKD) is closely linked to chronic inflammation, which plays a key role in its progression. The study aimed to investigate the association between the aggregate index of systemic inflammation (AISI) and CKD prevalence. We analyzed data from the National Health and Nutrition Examination Survey, which was conducted between 2007 and 2018. Multivariate logistic regression analyses were used to assess the independent relationship between AISI and CKD. Nonlinear relationships between AISI and CKD were examined through smooth curve fitting and threshold effect analyses. A total of 24,386 adult participants were included. After controlling for possible confounding variables, a significant positive association between AISI and CKD was identified (OR = 1.05, [95% CI: 1.03-1.07], P < .001). Subgroup analyses and interaction tests revealed significant differences in this association across diabetes strata (P < .05). Smoothing curve analysis demonstrated a nonlinear positive correlation between AISI and CKD. Moreover, threshold analysis revealed a saturation effect with an inflection point at 720 (1000 cells/μL). Below this threshold (AISI < 720, 1000 cells/μL), AISI was significantly positively associated with CKD, while no significant association was observed above the threshold (AISI > 720, 1000 cells/μL). These findings reveal a notable positive correlation between AISI and CKD among adults in the United States, with an inflection point at 720 (1000 cells/μL). The AISI shows potential as an indicator associated with CKD, but further comprehensive prospective studies are needed to confirm its role in CKD development and its utility in clinical practice.

Neuroblastoma (NB) is the most common type of pediatric extra-cranial tumor that arises in the sympathetic nervous system. The heterogeneity of T-cell exhaustion (TEX) has been linked to the determination of distinct clinical outcomes and the effectiveness of immunotherapy in numerous adult malignancies. Therefore, studying the heterogeneous TEX landscape in NB as well as its impact on clinical outcomes is meaningful. The gene expression and clinical datasets of the Sequencing Quality Control (SEQC), E-MTAB-8248, and Therapeutically Applicable Research to Generate Effective Treatments (TARGET) cohorts were downloaded from publicly available databases. Two TEX-related clusters for neuroblastoma were identified in the SEQC cohort. Patients in TEX-C1 exhibited superior overall survival (OS) and event-free survival (EFS) rates compared with those in TEX-C2. And TEX-C1 had more immune cells infiltrating, as well as higher expression of immune checkpoint genes. A total of 1984 genes were differentially expressed between these two clusters, of which 1712 were associated with OS. A gene signature consisting of ten TEX-related genes was developed, and a risk score was computed for each patient. Based on the risk score, SEQC patients were split into high- and low-risk groups with significantly different survival rates. The risk score was an independent risk factor predicting survival and showed superior prediction power for 3, 5, and 10-year survival compared to individual clinical parameters. The signature was further confirmed in the TARGET and E-MTAB-8248 cohorts. This study has successfully constructed a risk score model for NB prognosis, utilizing TEX as its foundation. The model provides risk classification and survival evaluation, which can further guide treatment.

Melanoma and non-small cell lung cancer (NSCLC) display exceptionally high mutational burdens. Hence, immune targeting in these cancers has primarily focused on tumor antigens (TAs) predicted to derive from nonsynonymous mutations. Using comprehensive proteogenomic analyses, we identified 589 TAs in cutaneous melanoma (n = 505) and NSCLC (n = 90). Of these, only 1% were derived from mutated sequences, which was explained by a low RNA expression of most nonsynonymous mutations and their localization outside genomic regions proficient for major histocompatibility complex (MHC) class I-associated peptide generation. By contrast, 99% of TAs originated from unmutated genomic sequences specific to cancer (aberrantly expressed tumor-specific antigens (aeTSAs), n = 220), overexpressed in cancer (tumor-associated antigens (TAAs), n = 165) or specific to the cell lineage of origin (lineage-specific antigens (LSAs), n = 198). Expression of aeTSAs was epigenetically regulated, and most were encoded by noncanonical genomic sequences. aeTSAs were shared among tumor samples, were immunogenic and could contribute to the response to immune checkpoint blockade observed in previous studies, supporting their immune targeting across cancers.

T-cell receptor T-cell engagers (TCR-TCE) are soluble bispecific proteins composed of TCR and anti-CD3 antibodies, which can effectively redirect tumor-infiltrating T cells to kill tumor cells. However, TCR-TCE development and clinical application are significantly hindered by the instability of natural TCRs and immunosuppressive tumor microenvironment, underscoring the urgent need for alternative engineering strategies. Here, we describe a strategy that utilizes artificial cell membrane nanoparticle technology to generate a TCR nanovesicle antibody (TPC NV), which presents tumor-specific TCR, anti-CD3, and PD-1 antibodies on its membrane, representing a novel TCR-TCE with therapeutic efficacy against solid tumors. TPC NV binds to tumor cells through TCR, redirects tumor-infiltrating T cells via anti-CD3 antibodies, and reverses immunosuppression with anti-PD-1 antibodies, thereby inducing a broad-spectrum T cell response that effectively eliminates established tumors. Furthermore, epacadostat, an inhibitor of indoleamine 2,3-dioxygenase, can be loaded into TPC NV to suppress regulatory T cell (Treg) generation and enhance dendritic cell (DC) maturation by inhibiting tumor tryptophan metabolism. This dual action amplifies adaptive immune activation and triggers a robust systemic anti-tumor immune response.

Exhausted CD8 T cells (TEX) arising during chronic infections and cancer have reduced functional capacity and limited fate flexibility that prevents optimal disease control and response to immunotherapies. Compared to memory (TMEM) cells, TEX have a unique open chromatin landscape underlying a distinct gene expression program. How TEX transcriptional and epigenetic landscapes are regulated through histone post-translational modifications (hPTMs) remains unclear. Here, we profiled key activating (H3K27ac and H3K4me3) and repressive (H3K27me3 and H3K9me3) histone modifications in naive CD8 T cells (TN), TMEM and TEX. We identified H3K27ac-associated super-enhancers that distinguish TN, TMEM and TEX, along with key transcription factor networks predicted to regulate these different transcriptional landscapes. Promoters of some key genes were poised in TN, but activated in TMEM or TEX whereas other genes poised in TN were repressed in TMEM or TEX, indicating that both repression and activation of poised genes may enforce these distinct cell states. Moreover, narrow peaks of repressive H3K9me3 were associated with increased gene expression in TEX, suggesting an atypical role for this modification. These data indicate that beyond chromatin accessibility, hPTMs differentially regulate specific gene expression programs of TEX compared to TMEM through both activating and repressive pathways.

T cells are pivotal in combating cancer; however, they can become exhausted during tumour progression, losing their cytotoxic capacity and upregulating inhibitory receptors including PD-1 and TIGIT. While checkpoint blockade has emerged as a potent treatment option for numerous cancers, patient selection, long-term efficacy, and adverse effects still remain an issue. For these reasons, it is important to investigate other pathways that might lead to selective reactivation of the immune system. Co-stimulatory TNFRSF receptors, including 4-1BB and OX-40, have emerged as promising targets for reactivating exhausted T cells. However, their expression on exhausted peripheral and tumour-infiltrating lymphocytes (TILs) is not well characterised, particularly in cervical cancer (CC), which remains the leading cause of gynaecological cancer mortality in low- and middle-income countries. To investigate the expression of these receptors, PBMCs were collected from CC patients and healthy donors, along with TILs from tumour biopsies, and analysed using multiparametric flow cytometry. Our findings revealed an increased population of phenotypically exhausted (PD-1+TIGIT+) CD4+ and CD8+ T cells in TILs, and, to a lesser extent, in peripheral blood and from CC patients. These exhausted T cell subsets exhibited selective overexpression of 4-1BB and OX-40 compared to phenotypically non-exhausted cells (PD-1-TIGIT-). In TILs, 4-1BB was overexpressed 12.7-fold in CD8 cells with the exhausted phenotype, OX-40 was overexpressed 3.3-fold; in CD4 cells with the exhausted phenotype, the overexpression was 7.8× and 3.8× for 4-1BB and OX-40, respectively. CD8 and CD4 T cells that were PD-1 + TIGIT+ 4-1BB+ were 7.3× and 16× more likely to be found in the tumour versus peripheral blood. Additionally, subpopulations of PD-1high T cells were significantly elevated in the tumour-infiltrating T cells and TIGIT expression was positively associated with PD-1 levels in peripheral patient CD8+ and CD4+ T cells, potentially indicating an advanced state of exhaustion. These findings suggest that TNFRSF members, especially 4-1BB, may serve as potential immunotherapeutic targets for reinvigorating exhausted T cells in CC.

Acute myeloid leukemia (AML) lacks effective prognostic markers. While lymphocyte subsets are recognized as valuable predictive indicators in hematologic malignancies, their role in AML remains largely unexplored, particularly during different stages of AML. Our study analyzed the levels and changes of lymphocyte subsets in AML patients at newly diagnosed (ND) and first complete remission (CR) status, and explored the correlation between lymphocyte subsets and prognosis in different disease stages. Flow cytometry detected peripheral blood lymphocyte subsets in 145 ND AML patients, 125 CR AML patients, and 47 healthy controls (HCs). Dynamic testing was conducted on 28 AML patients at both ND and CR status. Our study found significant differences in lymphocyte subsets between ND, CR, and HCs, with notable changes in CD3+T, CD4+T, CD8+T, effector T (Teff), B, and natural killer (NK) cells between ND and CR status. Low frequencies of CD8+T below HCs thresholds and high regulatory T cell (Treg) frequency above HCs thresholds in the ND group, were independent risk factors for non-response to treatment. ROC curves evaluated the prognostic value of lymphocyte subsets and established cutoff values. Lymphocyte subsets in the ND group were not significantly associated with relapse or survival. Low absolute counts of CD3+T, B, and NK cells in the CR group were linked to AML relapse, and a low NK cell count was an independent predictor of overall survival (OS). Lymphocyte subsets can act as prognostic biomarkers, and their dynamic monitoring predicts treatment response, relapse, and survival in AML.

While CD49d (α4 integrin) is an established prognostic marker in chronic lymphocytic leukaemia (CLL) and is associated with aggressive disease, its impact on T-cell biology remains poorly understood. Compared to healthy donors, CLL patients exhibited significantly elevated CD49d expression in both CD4+ and CD8+ T cells (p < 0.001) as detected by flow cytometry, which was also confirmed by the single-cell RNA sequencing (scRNA-seq) (p < 0.001). Differentially expressed genes in CD49d+ T (both CD8+ and CD4+ T cells) versus CD49d- T cells identified in CLL patients were enriched in cellular senescence pathways, while this phenomenon is absent in healthy individuals. Functional validation demonstrated that CD49d+ T cells displayed elevated senescence-associated markers (e.g. interferon-gamma, granzyme B) and a shift towards memory phenotypes, correlating with immunosuppressive signatures. This discovery suggests that targeting CD49d-dependent senescence pathways may reverse T-cell dysfunction in CLL immunotherapy.

Immunosenescence is the dysfunction of the immune system that occurs with age, a process that is complex and characterized by several features, of which T-cell senescence is one of the key manifestations. In the tumor microenvironment, senescent T cells lead to the inability of tumor cells to be effectively eliminated, triggering immunosuppression, which in turn affects the efficacy of immunotherapy. This is a strong indication that T-cell senescence significantly weakens the immune function of the body, making individuals, especially elderly patients with cancer, more vulnerable to cancer attacks. Despite the many challenges, T-cell senescence is important as a potential therapeutic target. This review provides insights into the molecular mechanisms of T-cell senescence and its research advances in patients with cancer, especially in older adults, and systematically analyzes potential intervention strategies, including molecular mechanism-based interventions, the use of immune checkpoint inhibitors, and CAR-T cell therapy. It is hoped that this will establish a theoretical framework for T-cell senescence in the field of tumor immunology and provide a scientific and prospective reference basis for subsequent in-depth research and clinical practice on senescent T cells.

Immunotherapy has transformed the neoadjuvant treatment landscape for patients with resectable locally advanced non-small cell lung cancer (NSCLC). However, a population of patients cannot obtain major pathologic response (MPR) and thus benefit less from neoadjuvant immunotherapy, highlighting the need to uncover the underlying mechanisms driving resistance to immunotherapy.

Two published single-cell RNA sequencing (scRNA-seq) datasets were used to analyze the subsets of cancer-associated fibroblasts (CAFs) and T cells and functional alterations after neoadjuvant immunotherapy. The stromal signature predicting ICI response was identified and validated using our local cohort with stage III NSCLC receiving neoadjuvant immunotherapy and other 4 public ICI transcriptomic cohorts.

Non-MPR tumors showed higher enrichment of CAFs and increased extracellular matrix deposition than MPR tumors, as suggested by bioinformatic analysis. Further, CAF-mediated immune suppression may involve reciprocal interactions with T cells in addition to a physical barrier mechanism. In contrast, MPR tumors demonstrated therapy-induced activation of memory CD8+ T cells into an effector phenotype. Additionally, neoadjuvant immunotherapy resulted in expansion of precursor exhausted T (Texp) cells, which were remodeled into an anti-tumor phenotype. Notably, we identified metabolic heterogeneity within distinct T cell clusters during immunotherapy. Methionine recycling emerged as a predictive factor for T-cell differentiation and a favorable pathological response. The stromal signature was associated with ICI response, and this association was validated in five independent ICI transcriptomic cohorts.

These discoveries underscore the distinct tumor microenvironments in MPR and non-MPR patients and may elucidate resistance mechanisms to immunotherapy in NSCLC.

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by dysregulated immune responses, resulting in sustained inflammation and ulceration of the colonic and rectal mucosa. To elucidate the cellular subtypes and gene expression profiles implicated in the pathogenesis of UC, we utilized single-cell and spatial transcriptomic analyses.

We conducted an analysis of single-cell data to identify cell types involved in the pathogenesis of UC. Employing machine learning methodologies, we screened for key genes implicated in UC and validated these findings through spatial transcriptomics. Additionally, immunohistochemistry was performed on UC lesion samples to investigate the expression patterns of the identified key genes. In an animal model, we utilized immunofluorescence and western blotting to validate the expression of these genes in the affected intestinal segments.

Our investigation identified specific monocyte subtypes associated with UC through a comprehensive analysis involving cell communication, Least Absolute Shrinkage and Selection Operator (LASSO), and Support Vector Machine (SVM) methodologies. Notably, two genes, G protein subunit gamma 5 (GNG5) and tissue inhibitor of metalloproteinase 1 (TIMP1), were identified as key regulators of UC development. Spatial transcriptomic indicated a downregulation of GNG5 expression in UC, whereas TIMP1 expression was upregulated. Furthermore, a significant correlation was detected between TIMP1 and T cell exhaustion-related genes such as genes related to T cell exhaustion, including T cell immunoreceptor with Ig and ITIM domains (TIGIT) and cytotoxic T-lymphocyte-associated protein 4 (CTLA4). Immunohistochemical analysis of UC lesion samples revealed diminished expression levels of GNG5 and elevated expression levels of TIMP1. A dextran sulfate sodium (DSS)-induced colitis mouse model was developed, demonstrating that the protein expression levels of GNG5 in the colonic tissue of model mice were significantly decreased compared to controls w)ile the expression levels of TIMP1 were increased (p < 0.01). Furthermore, immunofluorescence staining indicated co-localization of TIMP1 with the macrophage marker F4/80 in monocytes.

Our research delineated distinct monocyte subtypes correlated with UC and identified two pivotal genes, GNG5 and TIMP1, that contribute to the disease's pathogenesis. These insights offer a significant theoretical basis for enhancing the clinical diagnosis and therapeutic strategies for patients with UC.

Ovarian cancer (OC) progression is heavily influenced by the tumor microenvironment (TME), where immune suppression plays a critical role. This study explores the role of thrombospondin-1 (THBS1) in regulating tumor-associated macrophages (TAMs), T cell exhaustion, and immune checkpoint expression, as well as its transcriptional regulation by SNF2H.

We analyzed THBS1 expression and its clinical significance using publicly available datasets (TCGA-OV, GSE14407) and tissue microarrays containing OC and adjacent normal tissues. In vitro functional studies were conducted using OC cell lines (SKOV3, A2780) and co-cultures with macrophages. Chromatin immunoprecipitation (ChIP) assays and RNA interference were employed to investigate SNF2H-mediated transcriptional regulation of THBS1. In vivo, the role of THBS1 in immune suppression was validated using mouse tumor models.

THBS1 was significantly overexpressed in OC tissues and associated with poor prognosis. High levels of THBS1 correlated with increased TAM infiltration, M2 macrophage polarization, and upregulation of immune checkpoints PD-L1 and GAL-3, which contribute to T cell exhaustion. Functional assays demonstrated that THBS1 promotes macrophage recruitment and induces M2 polarization through TGF-β1 and IL-4 signaling. Additionally, ChIP assays identified SNF2H as a transcriptional regulator of THBS1, contributing to its overexpression. In vitro targeting of THBS1 reduced TAM-mediated immune suppression and restored T cell cytotoxicity.

This study positions THBS1 as a key regulator of the OC TME, linking TAM recruitment and polarization to CD8+ T cell exhaustion via immune checkpoint modulation. By identifying SNF2H as a transcriptional regulator of THBS1, we offer new insights into its epigenetic dysregulation and suggest potential therapeutic strategies to reprogram the TME and improve the effectiveness of immunotherapy.

The increasing number of new cancer cases and cancer-related deaths worldwide highlights the urgent need to develop novel anti-tumor treatment methods to alleviate the current challenging situation. Nearly all organisms are capable of secreting extracellular vesicles (EVs), and these nano-scale EVs carrying biological molecules play an important role in intercellular communication, further affecting various physiological and pathological processes. Notably, EVs from different sources have differences in their characteristics and functions. Consequently, diverse EVs have been utilized as drug or vaccine delivery carriers for improving anti-tumor treatment due to their good safety, ease of modification and unique properties, and achieved satisfactory results. Meanwhile, the clinical trials of EV-based platform for tumor therapy are also continuously being conducted. Therefore, in this review, we summarize the recent research progress of EV-based tumor treatment methods, including the introduction of main sources and unique functions of EVs, the application of EVs in tumor treatment as well as their prospects and challenges. Additionally, considering the unique advantages of artificial EVs over natural EVs, we also highlighted their characteristics and applications in tumor treatments. We believe that this review will help researchers develop novel EV-based anti-tumor platforms through a bottom-up design and accelerate the development in this field.

Management of persistent inflammation, immunosuppression, and catabolism syndrome (PICS) after sepsis remains challenging for patients in the intensive care unit, experiencing poor quality of life and death. However, immune-cell signatures in patients with PICS after sepsis remain unclear.

We determined immune-cell signatures of PICS after sepsis at single-cell resolution. Murine cecal ligation and puncture models of PICS were applied for validation.

Immune functions of two enriched monocyte subpopulations, Mono1 and Mono4, were suppressed substantially in patients with sepsis and were partially restored in patients with PICS after sepsis and exhibited immunosuppressive and pro-apoptotic effects on B and CD8T cells. Patients with PICS and sepsis had reduced naive and memory B cells and proliferated plasma cells. Besides, naive and memory B cells in patients with PICS showed an active antigen processing and presentation gene signature compared to those with sepsis. PICS patients with better prognoses exhibited more active memory B cells and IGHA1-plasma cells. CD8TEMRA displayed signs of proliferation and immune dysfunction in the PICS-death group in contrast with the PICS-alive group. Megakaryocytes proliferation was more pronounced in patients with PICS and sepsis than in healthy controls, with notable changes in the anti-inflammatory and immunomodulatory effects observed in patients with PICS and verified in mice models.

Our study evaluated PICS after sepsis at the single-cell level, identifying the heterogeneity present within immune-cell subsets, facilitating the prediction of disease progression and the development of effective intervention.

This work was supported by the National Natural Science Foundation of China, Shanghai Municipal Health Commission "Yiyuan New Star" Youth Medical Talent Cultivating Program, and Shanghai Clinical Research Center for Anesthesiology.

Prolonged viral infections often lead to lymphocyte exhaustion, marked by heightened inhibitory receptor expression like PD-1, compromising host defense mechanisms. The unexplored potential of chemical checkpoint inhibitors in rejuvenating immune responses prompted our investigation.

We focused on CCT007093, a Wip1 inhibitor, screened for its distinctive capacity to simultaneously decrease PD-1 and FcγRIIB expression in B cells.

In this study, we harnessed a murine model of immune exhaustion induced by chronic hepatitis B virus (HBV) infection using hydrodynamic injection. Treatment with CCT007093 resulted in decreased levels of PD-1 expression, resulting in reduced percentages of PD-1+/hi CD4+ and CD8+ T cells in circulation, spleen, and liver. The expression levels of PD-1 and FcγRIIB, along with the percentages of PD-1+/hi and FcγRIIB+/hi CD19+ B cells in these tissues, were similarly diminished. Moreover, intrahepatic lymphocytes treated with CCT007093 displayed heightened responsiveness to ex vivo activation. Consequently, mice treated with CCT007093 exhibited significantly reduced serum HBsAg levels compared to vehicle-treated mice. Our detailed analyses, spanning promoter and transcriptome evaluations, uncovered p65 NF-κB as the primary activator of T cells and B cells, while Ying Yang 1 (YY1) emerged as the key regulator, orchestrating the down-regulation of PD-1 and FcγRIIB gene transcription in response to CCT007093.

Our study highlights the prowess of chemical checkpoint inhibitors, exemplified by CCT007093, in alleviating immune exhaustion in HBV-infected mice, particularly by enhancing adaptive immunity.

Although the treatment landscape for advanced hepatocellular carcinoma (HCC) has seen significant advancements in the past decade with the introduction of immune checkpoint inhibitors and antiangiogenic drugs, progress has fallen short of expectations. Recently, a novel engineered oncolytic virus (OHSV2) that secretes dual-specific T-cell engagers (DSTEs) targeting the fibroblast activation protein (FAP) was developed and combined with GPC3-targeting CAR-T cells and immunotoxins to exert a synergistic antitumor effect.

OHSV2-DSTEFAP5/CD3 was initially generated by transducing the DSTEs engaging FAP5 on fibroblasts into the backbone of our oncolytic virus OHSV2. An innovative high-order combination was devised in a xenograft mouse model to conceptually explore whether enhanced anti-tumor effects could be achieved. Additionally, the underlying mechanisms of synergistic effects and safety profiles were preliminarily investigated.

OHSV2-DSTEFAP5/CD3 effectively targeted and eliminated fibroblasts in vitro while maintaining cytotoxicity and inducing immune activation compared to parental OHSV2. In vivo, dose-adjusted combination therapy resulted in a remarkable antitumor effect compared to control treatments, leading to tumor regression in 40% of mice without significant toxicity to major organs. Mechanistically, rather than directly depleting fibroblasts, OHSV2-DSTEFAP5/CD3 played an essential role in priming T-cell proliferation, infiltration, and activation, and inhibiting the supportive interaction between cancer cells and fibroblasts.

This high-order combination represents a novel multiple-wave immunotherapeutic approach for HCC. Despite being a conceptual exploration, this strategy has demonstrated promising therapeutic efficacy and acceptable safety profiles.