T-cell exhaustion in the tumor microenvironment

Hierarchical protein nano-crystalline hydrogel with extracellular vesicles for ectopic lymphoid structure formation

Among cancer therapies, immune checkpoint blockade (ICB) has emerged as a prominent approach, substantially enhancing anti-tumor immune responses. However, the efficacy of ICB is often limited in the absence of a pre-existing immune response within the tumor microenvironment. Here, we introduce a novel hierarchical protein hydrogel platform designed to facilitate the formation of artificial tertiary lymphoid structures (aTLS), thereby improving ICB efficacy. Through the integration of self-assembling ferritin protein nanocages, rec1-resilin protein, and CP05 peptide, our hierarchical hydrogels provide a structurally supportive and functionally adaptive scaffold capable of on-demand self-repair in response to mild thermal treatments. The effective encapsulation of extracellular vesicles (EVs) via the CP05 peptide ensures the formation of aTLS with germinal center-like structures within the hierarchical hydrogel. We demonstrate that, combined with ICB therapy, EV-loaded hierarchical hydrogels also induce the TLS within the tumor, markedly promoting immune responses against ICB-resistant tumor. This bioactive hydrogel platform offers a versatile tool for enhancing a broad range of immunotherapies, with potential applications extending beyond TLS to other frameworks that support complex tissue architectures.

Anti-PD1 prolongs the response of PI3K and farnesyl transferase inhibition in HRAS- and PIK3CA-mutant head and neck cancers

BACKGROUND

Tipifarnib, a farnesyl transferase inhibitor, has shown promising response in the treatment of HRAS-mutant HNSCC in the clinic, and in combination with a PI3K inhibitor in PIK3CA-mutant mouse models; however, the involvement of antitumor immunity in the efficacy of tipifarnib has not yet been investigated. This study aimed to evaluate the involvement of antitumor immunity in the efficacy of tipifarnib in HRAS- or PIK3CA-mutant HPV-positive and HPV-negative head and neck cancer murine models.

METHODS

To investigate the role of antitumor immunity, we compared the efficacy of tipifarnib in immune-intact C57BL/6 mice and immunodeficient NSG mice. Histopathological analyses were conducted to evaluate PD-L1 expression and the activation of key signaling pathways. Additionally, the synergistic potential of tipifarnib with the PI3Kα inhibitor alpelisib (BYL719) was assessed in vitro and in vivo. Immunohistochemical analysis was performed to examine the infiltration of CD8+T cells, and anti-PD1 treatment was tested to evaluate its potential to prolong progression-free survival.

RESULTS

In the HPV-positive HRAS-mutant HNSCC model, the antitumor efficacy of tipifarnib was primarily dependent on CD8+T cell activity, whereas in HPV-negative cancers, the contribution of antitumor immunity was less pronounced. Tipifarnib treatment upregulated PD-L1 expression, potentially inhibiting T cell antitumor activity and inducing hyperactivation of the AKT pathway, which mitigated MAPK inhibition and promoted cell proliferation. Blocking the PI3K pathway with alpelisib demonstrated synergistic antitumor effects in all models. The combination of tipifarnib and alpelisib exhibited greater efficacy in immune-intact mice than in immunodeficient mice, and was accompanied by increased CD8+T cell infiltration. Adding anti-PD1 treatment to the tipifarnib/alpelisib combination further prolonged progression-free survival in tumor-bearing mice.

CONCLUSION

These findings underscore the critical role of antitumor immunity, particularly CD8+T cell activity, in the efficacy of tipifarnib alone and in combination with alpelisib. The triple combination of tipifarnib, alpelisib, and anti-PD1 treatment showed superior antitumor activity and extended survival in preclinical models, suggesting its potential as a therapeutic strategy for HNSCC patients with HRAS- and PIK3CA-mutation.

Ruxolitinib and oHSV combination therapy increases CD4 T cell activity and germinal center B cell populations in murine sarcoma

Malignant peripheral nerve sheath tumors (MPNSTs) are a highly aggressive neoplasm of the peripheral nervous system and are resistant to most conventional cancer therapies. We previously showed that pretreatment with ruxolitinib (RUX) enhanced the efficacy of oncolytic herpes simplex virus (oHSV) virotherapy in this murine sarcoma model. A low abundance of tumor-infiltrating leukocytes and limitations in conventional flow cytometry restrict analyses to a narrow subset of immune cells, potentially introducing a confirmation bias. To address these limitations, we developed a 46-color spectral flow cytometry panel for the detailed analysis of immune cell dynamics following repeated oHSV dosing. Beyond the cytotoxic T lymphocyte (CTL) and regulatory T cell (Treg) changes reported in our earlier studies, RUX+oHSV treatment modulates myeloid and other lymphoid compartments, including germinal center B cell populations with enhanced activation. RUX+oHSV therapy also increased cytokine-expressing CD4(+) populations, predominantly granzyme B(+) cytotoxic-like, interferon (IFN)-γ(+) T helper type 1 (Th1)-like, and interleukin (IL)-21(+) T follicular helper (Tfh)-like phenotypes, within the tumor infiltrates, suggestive of potential tertiary lymphoid structure development in the treated tumors. Here, we illustrate the utility of a high-dimensional spectral flow cytometry panel that permits simultaneous evaluation of intratumoral CD4/CD8 T cell, Treg, γδ-T cell, natural killer T (NKT) cell, B cell, NK cell, monocyte, macrophage, granulocyte, myeloid-derived suppressor cell (MDSC), and dendritic cell functional changes from RUX+oHSV-treated MPNSTs.

Rejuvenation of Tumor-Specific T Cells via Ultrahigh DAR Antibody-Polymeric Imidazoquinoline Complexes: Coordinated Targeting of PDL1 and Efficient TLR7/8 Activation in Intratumoral Dendritic Cells

Intratumoral dendritic cells (DCs) are pivotal in tumor treatment due to their immature and pro-tumoral state induced by the tumor microenvironment. Clinically, these immature DCs correlate with disease progression and recurrence, adversely affecting prognosis. Activation of DCs by the TLR7/8 agonist imidazoquinoline (IMDQ) has yielded promising results, but they are limited by systemic inflammation risks, and high programmed death ligand 1 (PDL1) expression on DCs impedes CD8+ T cell activity. Thus, the study introduces an antibody-polymeric IMDQ complex (αPDL1-PLG-IMDQ) with an ultrahigh drug-to-antibody ratio, where αPDL1 is conjugated to Fc-binding peptides on polymeric IMDQ. This complex targets high PDL1-expressing intratumoral DCs with high probability, inducing PDL1-mediated endocytosis to deliver IMDQ to TLR7/8 within endosomes, effectively activating DCs (CD11c+MHC II+: 2.33% versus 1.09%, CD11c+CD86+: 2.49% versus 1.00% on tumors compared to phosphate-buffered saline treatment) and priming T cells. It also blocks PDL1/PD1 interactions, enhancing tumor-specific T-cell activation and memory. Notably, αPDL1-PLG-IMDQ achieved a 97% tumor inhibition rate, prevented tumor regrowth in rechallenge experiments, and reduced lung metastases of tumors by 83%. These findings underscore its potential for intratumoral DC-targeted immunotherapy and novel systemic IMDQ and checkpoint inhibitor combinations.

Fc-mediated immune stimulating, pro-inflammatory and antitumor effects of anti-HER2 IgE against HER2-expressing and trastuzumab-resistant tumors

BACKGROUND

Anti-human epidermal growth factor receptor 2 (HER2) IgG1-based antibody therapies significantly improve cancer prognosis, yet intrinsic or acquired resistance to fragment antigen-binding (Fab)-mediated direct effects commonly occurs. Most resistant tumors retain antigen expression and therefore remain potentially targetable with anti-HER2 therapies that promote immune-mediated responses. Tumor-antigen-specific IgE class antibodies can mediate powerful immune cell-mediated effects against different cancers and have been shown to activate IgE Fc receptor-expressing monocytes. We previously reported the engineering of a trastuzumab-equivalent anti-HER2 IgE antibody and showed early evidence of Fc-mediated cancer cell-targeting effects. In the present study, we evaluated the anti-tumoral functions of two anti-HER2 IgEs, trastuzumab and pertuzumab IgE.

METHODS

In vitro functionality of the two anti-HER2 antibodies was assessed by HER2 phosphorylation and ligand-independent viability assays, as well as basophil (RBL-SX38) degranulation, antibody-dependent cellular cytotoxicity/antibody-dependent cellular phagocytosis(ADCC/ADCP) assays and primary monocyte stimulation assays. The potential to trigger a hypersensitivity type I reaction was investigated using the basophil activation test (BAT). anti-tumoral efficacy was assessed in two humanized HER2+, trastuzumab-resistant models in vivo. Changes in the tumor microenvironment were assessed by flow cytometry or bulk RNA sequencing.

RESULTS

We demonstrate the anti-tumoral and immunostimulatory functions of two anti-HER2 IgEs derived from variable region sequences of the clinically available trastuzumab and pertuzumab IgG1 antibodies. IgE engagement of monocytes via the Fc region induced tumor cell cytotoxicity and a pro-inflammatory shift with upregulation of immune-stimulatory CD40, CD80 and CD86, and downregulation of scavenger CD163, cell surface molecules. This was accompanied by enhanced pro-inflammatory tumor necrosis factor (TNF)-α, interleukin (IL)-6, IL-1β cytokine production. The absence of basophil activation by anti-HER2 IgEs ex vivo in whole blood points to potentially safe administration in humans. In two trastuzumab-resistant HER2+ tumor xenograft models in immunodeficient mice reconstituted with human immune cells, the trastuzumab-equivalent anti-HER2 IgE restricted tumor growth. Treatment was associated with enriched classical (CD14+CD16-) monocyte and lower alternatively-activated (CD163+CD206+) macrophage infiltration, and higher densities of activated CD4+ (CD127loCD25hi) T cells and favorable effector T cell(Teff) to regulatory T cell (Treg) ratios in tumors.

CONCLUSION

Collectively, anti-HER2 IgE maintains Fab-mediated antitumor activity, induces Fc-mediated effects against HER2-expressing tumor cells, and stimulates remodeling of the immune microenvironment in tumors to promote pro-inflammatory cell phenotypes which could translate to improved outcomes for patients.

Pan-cancer characterization of m6A-mediated regulation of T cell exhaustion dynamics and clinical relevancies in human cancers

T cell exhaustion (TEX) is a major barrier to effective immunotherapy. The role of N6-methyladenosine (m6A) modification in regulating immune cell function has been recognized, but its impact on TEX dynamics across cancer types and clinical outcomes remains unclear. Here, we conducted a pan-cancer analysis integrating multi-omics data from cell lines, single-cell RNA sequencing, and pan-cancer and immunotherapy datasets to explore the dynamic interplay between m6A modification and TEX. We found that m6A modification influences key TEX-associated genes at both the cellular and single-cell levels, with distinct expression patterns across the exhaustion spectrum. Based on m6A-TEX interactions, three pan-cancer subtypes were identified, each with unique molecular profiles, immune phenotypes, and survival outcomes. The TexLm6AL subtype, characterized by low m6A activity and low TEX, correlated with high immune infiltration, increased cytolytic activity, and favorable survival, whereas the TexLm6AH and TexHm6AH subtypes with higher m6A activity were associated with poorer survival. Multivariate analysis confirmed the prognostic value of this classification independent of traditional clinical factors. Moreover, m6A-TEX crosstalk influenced responses to immune checkpoint blockade therapies. Our findings provide novel insights into the role of m6A in TEX regulation and underscore the potential of m6A regulators as biomarkers and therapeutic targets for advancing cancer immunotherapy.

The epigenetic hallmarks of immune cells in cancer

Targeting the dysregulation of epigenetic mechanisms in cancer has emerged as a promising therapeutic strategy. Although the significant rationale progress of epigenetic therapies in blocking cancer cells, how epigenetic regulation shapes tumor microenvironment (TME) and establishes antitumor immunity remains less understood. Recent study focus has been put on the epigenetic-mediated changes in the fate of immune cells, including the differentiation, expansion, recruitment, functionalization, and exhaustion of T cells, natural killer (NK) cells, tumor-associated macrophages (TAMs), dendritic cells (DCs), myeloid-derived suppressor cells (MDSCs), and B cells within the TME. Here, we review the latest molecular and clinical insights into how DNA modifications, histone modification, and epitranscriptome-related regulations shape immune cells of various cancers. We also discuss opportunities for leveraging epigenetic therapies to improve cancer immunotherapies. This review provides the epigenetic foundations of cancer immunity and proposes the future direction of combination therapies.

Characterization of Exhausted T Cell Signatures in Pan-Cancer Settings

T cells play diverse roles in cancer immunology, acting as tumor suppressors, cytotoxic effectors, enhancers of cytotoxic T lymphocyte responses and immune suppressors; providing memory and surveillance; modulating the tumor microenvironment (TME); or activating innate immune cells. However, cancer cells can disrupt T cell function, leading to T cell exhaustion and a weakened immune response against the tumor. The expression of exhausted T cell (Tex) markers plays a pivotal role in shaping the immune landscape of multiple cancers. Our aim was to systematically investigate the role of known T cell exhaustion (Tex) markers across multiple cancers while exploring their molecular interactions, mutation profiles, and potential implications for immunotherapy. The mRNA expression profile of six Tex markers, LAG-3, PDCD1, TIGIT, HAVCR2, CXCL13, and LAYN was investigated in pan-cancer. Utilizing data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), The Cancer Proteome Atlas (TCPA), and other repositories, we characterized the differential expression of the Tex markers, their association with the patients' survival outcome, and their mutation profile in multiple cancers. Additionally, we analyzed the effects on cancer-related pathways and immune infiltration within the TME, offering valuable insights into mechanisms of cancer immune evasion and progression. Finally, the correlation between their expression and sensitivity to multiple anti-cancer drugs was investigated extensively. Differential expression of all six markers was significantly associated with KIRC and poor prognosis in several cancers. They also played a potential activating role in apoptosis, EMT, and hormone ER pathways, as well as a potential inhibitory role in the DNA damage response and RTK oncogenic pathways. Infiltration of different immune cells was also found to be associated with the expression of the Tex-related genes in most cancer types. These findings underline that the reviving of exhausted T cells can be used to enhance the efficacy of immunotherapy in cancer patients.

A functional single-cell metabolic survey identifies Elovl1 as a target to enhance CD8+ T cell fitness in solid tumours

Reprogramming T cell metabolism can improve intratumoural fitness. By performing a CRISPR/Cas9 metabolic survey in CD8+ T cells, we identified 83 targets and we applied single-cell RNA sequencing to disclose transcriptome changes associated with each metabolic perturbation in the context of pancreatic cancer. This revealed elongation of very long-chain fatty acids protein 1 (Elovl1) as a metabolic target to sustain effector functions and memory phenotypes in CD8+ T cells. Accordingly, Elovl1 inactivation in adoptively transferred T cells combined with anti-PD-1 showed therapeutic efficacy in resistant pancreatic and melanoma tumours. The accumulation of saturated long-chain fatty acids in Elovl1-deficient T cells destabilized INSIG1, leading to SREBP2 activation, increased plasma membrane cholesterol and stronger T cell receptor signalling. Elovl1-deficient T cells increased mitochondrial fitness and fatty acid oxidation, thus withstanding the metabolic stress imposed by the tumour microenvironment. Finally, ELOVL1 in CD8+ T cells correlated with anti-PD-1 response in patients with melanoma. Altogether, Elovl1 targeting synergizes with anti-PD-1 to promote effective T cell responses.

Neoadjuvant chemoradiotherapy up-regulates PD-L1 in radioresistant colorectal cancer

Background

Combining radiotherapy (RT) with immune checkpoint inhibitors (ICIs) is a promising strategy that can enhance the therapeutic efficacy of ICIs. However, little is known about RT-induced changes in the expression of immune checkpoints, such as PD-L1, and their clinical implications in colorectal cancer (CRC). This study aimed to investigate the association between responsiveness to RT and changes in PD-L1 expression in human CRC tissue and cell lines.

Methods

Tissue specimens from preoperative biopsy via sigmoidoscopy and surgical resection were obtained from 24 patients with locally advanced rectal cancer (LARC) who underwent neoadjuvant chemoradiation therapy (CRT) between August 2016 and December 2017. Immunohistochemistry for PD-L1 in formalin-fixed paraffin-embedded tissue was performed from the endoscopic biopsy and surgical specimens. RNA sequencing was performed using 11 pairs of human LARC tissues before and after irradiation. After exposing human CRC cells to radiation, we investigated changes in the expression levels of PD-L1 and its regulatory signaling pathways.

Results

Patients were classified by tumor regression grade into responders (grade 2; 9 patients, 37.5 %) and non-responders (grades 3, 4, or 5; 15 patients, 62.5 %). In the non-responder group, 13 patients had low PD-L1 expression, but neoadjuvant CRT increased PD-L1 expression in 7 patients (53.9 %) (McNemar's test, p=0.034). CRT up-regulated PD-L1 in non-responder LARC tissues. Similarly, radiation increased PD-L1 in radioresistant DLD-1 cells more than in radiosensitive HCT116 cells, also affecting PD-L1-regulating genes and immune checkpoints in CRC cells. Conventional fractionated radiation treatment further increased PD-L1 in DLD-1 cells compared to HCT116 cells.

Conclusions

This study demonstrated that radiation induces an increase in PD-L1 expression, which is more pronounced in radioresistant CRC, proving the theoretical framework for a combined treatment strategy with a PD-L1 blockade for locally advanced rectal cancer.

Effect of boswellic acids on the expression of PD-1 and TIGIT immune checkpoints on activated human T cells

Boswellic acids (BAs) have been documented as anti-inflammatory agents with the potential to regulate immune responses. However, their impacts on the expression level of immune checkpoint (IC) molecules in T cells have never been reported. By using flow cytometric assays, we investigated whether BAs extracted from Boswellia sacra (B. sacra) have any potential effects on the expression of PD-1 and TIGIT immune checkpoints (ICs) on activated T cells in vitro. Interestingly β-BA at a concentration of 50 μM significantly reduced the expression of PD-1 and TIGIT on both activated CD4+ and CD8+ T cells without any cytotoxicity. Additionally, β-KBA significantly reduced the percentages of CD4+PD-1+ and CD8+TIGIT+ T cells at 50 μM concentration. Furthermore, a significant reduction in CD4+PD-1+ T cells was observed following treatment with a lower concentration (25 μM) of β-AKBA. These findings show that BA compounds have the ability to reduce the expression of PD-1 and TIGIT in stimulated human T cells, which might play critical roles in reinvigorating exhausted T cells, indicating their potentials in immunosuppressed disease settings such as cancers and infections. This study is the first to investigate the effects of these compounds on the expression of immune checkpoints in human T cells. Clearly, further investigations are required to assess the mechanism of action of these compounds on ICs, and their efficacy as therapeutic agents in different diseases.

LOX+ iCAFs in HNSCC have the potential to predict prognosis and immunotherapy responses revealed by single cell RNA sequencing analysis

Carcinoma-associated fibroblasts (CAFs) exhibit significant heterogeneity and are closely associated with progression, resistance to anticancer therapies, and poor prognosis in head and neck squamous cell carcinoma (HNSCC). However, the specific functional role of CAFs in HNSCC has been inadequately explored. In this study, we utilized a single-cell RNA sequencing dataset from HNSCC (GSE103322) to recluster CAFs via the Seurat pipeline. On the basis of the reported markers, we identified two CAF subtypes, LOX-myCAFs and LOX + iCAFs, and generated signature markers for each. Through unsupervised consensus clustering, we identified and characterized two molecular subtypes of HNSCC-TCGA, each exhibiting distinct dysregulated cancer hallmarks, immunological tumor microenvironments, and stemness characteristics. The robustness of the LOX + iCAF-related signature clustering, particularly in terms of prognosis and prediction of immunotherapeutic response, was validated in an ANOVA cohort via a GEO dataset (GSE159067) consisting of 102 HNSCC patients. A positive correlation was validated between the expression of LOX and that of CD86, a marker of M1 macrophage polarization. Further experiments involving the coculture of conditioned medium derived from LOX-silenced CAFs with CAL-27 and UM-SCC-1 cell lines revealed that LOX silencing led to decreased proliferation and migration of these cancer cells, which was mediated by epithelial-mesenchymal transition (EMT) through IL-34- induced CSF1R/Akt signaling. In summary, our single-cell and bulk RNA sequencing analyses revealed a LOX + iCAF-related signature that can predict the prognosis and response to immunotherapy in HNSCC patients. Additionally, the LOX gene was identified as a promising therapeutic target for HNSCC treatment.

Impact of Tertiary Lymphoid Structure on Prognosis and Tumor Microenvironment in Undifferentiated Pleomorphic Sarcoma

Undifferentiated pleomorphic sarcoma (UPS) has a favorable objective response rate to anti-PD-1 drugs compared with other sarcomas. Tertiary lymphoid structure (TLS) is a favorable prognostic factor and a biomarker for immune checkpoint inhibitors (ICIs). Nevertheless, there are limited data on the tumor microenvironment (TME) to support a good response to ICIs in sarcoma. Therefore, this study was conducted to investigate the impact of TLS on prognosis and TME. A total of 52 of UPS with wide resection were divided into intratumoral TLS, extratumoral TLS, and without TLS groups. Survival analysis and immunohistochemistry were performed to evaluate immune cells and immune checkpoint molecules, and multiplexed immunofluorescence was conducted to evaluate T-cell exhaustion among the three groups. TLS was detected in 34 cases (65%), including 23 intratumoral TLS (44%) and 11 extratumoral TLS (21%) cases. Patients with TLS had significantly longer overall survival than those without TLS (log rank p = 0.020). The intratumoral TLS group had a significantly higher number of immune cells and higher expression of PD-L1 and IDO-1 than the without TLS group. Progenitor-exhausted T cells were also observed in patients with UPS. In conclusion, these findings could help predict prognosis in patients with UPS. TLS was demonstrated to be a favorable prognostic factor in patients with UPS. Intratumoral TLS may be a biomarker for the response to ICIs, especially anti-PD-1 drugs.

The Emerging Role of CD8+ T Cells in Shaping Treatment Outcomes of Patients with MDS and AML

CD8+ T cells are critical players in anti-tumor immunity against solid tumors, targeted by immunotherapies. Emerging evidence suggests that CD8+ T cells also play a crucial role in anti-tumor responses and determining treatment outcomes in hematologic malignancies like myelodysplastic neoplasms (MDS) and acute myeloid leukemia (AML). In this review, we focus on the implication of CD8+ T cells in the treatment response of patients with MDS and AML. First, we review reported studies of aberrant functionality and clonality of CD8+ T cells in MDS and AML, often driven by the immunosuppressive bone marrow microenvironment, which can hinder effective antitumor immunity. Additionally, we discuss the potential use of CD8+ T cell subpopulations, including memory and senescent-like subsets, as predictive biomarkers for treatment response to a variety of treatment regimens, such as hypomethylating agents, which is the standard of care for patients with higher-risk MDS, and chemotherapy which is the main treatment of patients with AML. Understanding the multifaceted role of CD8+ T cells and their interaction with malignant cells in MDS and AML will provide useful insights into their potential as prognostic/predictive biomarkers, but also uncover alternative approaches to novel treatment strategies that could reshape the therapeutic landscape, thus improving treatment efficacy, aiding in overcoming treatment resistance and improving patient survival in these challenging myeloid neoplasms.

Spatial transcriptomics-aided localization for single-cell transcriptomics with STALocator

Single-cell RNA-sequencing (scRNA-seq) techniques can measure gene expression at single-cell resolution but lack spatial information. Spatial transcriptomics (ST) techniques simultaneously provide gene expression data and spatial information. However, the data quality of the spatial resolution or gene coverage is still much lower than the quality of the single-cell transcriptomics data. To this end, we develop a ST-Aided Locator for single-cell transcriptomics (STALocator) to localize single cells to corresponding ST data. Applications on simulated data showed that STALocator performed better than other localization methods. When applied to the human brain and squamous cell carcinoma data, STALocator could robustly reconstruct the relative spatial organization of critical cell populations. Moreover, STALocator could enhance gene expression patterns for Slide-seqV2 data and predict genome-wide gene expression data for fluorescence in situ hybridization (FISH) and Xenium data, leading to the identification of more spatially variable genes and more biologically relevant Gene Ontology (GO) terms compared with the raw data. A record of this paper's transparent peer review process is included in the supplemental information.

Scalable intracellular delivery via microfluidic vortex shedding enhances the function of chimeric antigen receptor T-cells

Adoptive chimeric antigen receptor T-cell (CAR-T) therapy is transformative and approved for hematologic malignancies. It is also being developed for the treatment of solid tumors, autoimmune disorders, heart disease, and aging. Despite unprecedented clinical outcomes, CAR-T and other engineered cell therapies face a variety of manufacturing and safety challenges. Traditional methods, such as lentivirus transduction and electroporation, result in random integration or cause significant cellular damage, which can limit the safety and efficacy of engineered cell therapies. We present hydroporation as a gentle and effective alternative for intracellular delivery. Hydroporation resulted in 1.7- to 2-fold higher CAR-T yields compared to electroporation with superior cell viability and recovery. Hydroporated cells exhibited rapid proliferation, robust target cell lysis, and increased pro-inflammatory and regulatory cytokine secretion in addition to improved CAR-T yield by day 5 post-transfection. We demonstrate that scaled-up hydroporation can process 5 × 108 cells in less than 10 s, showcasing the platform as a viable solution for high-yield CAR-T manufacturing with the potential for improved therapeutic outcomes.

First-in-human evaluation of memory-like NK cells with an IL-15 super-agonist and CTLA-4 blockade in advanced head and neck cancer

BACKGROUND

Cytokine induced memory-like natural killer (CIML NK) cells combined with an IL-15 super-agonist (N-803) are a novel modality to treat relapsed/refractory head and neck cancer.

METHODS

We report data from a phase I trial of haploidentical CIML NK cells combined with N-803 with or without ipilimumab (IPI) in relapsed/refractory head and neck cancer patients after a median of 6 prior lines of therapy. The trial adhered to a 3 + 3 dose de-escalation design, with primary endpoint being safety. High-resolution immunophenotypic and transcriptional profiling characterized the NK cells and their interacting partners in vivo.

RESULTS

The primary safety endpoint was established, with dose-limiting toxicity in 1/10 patients. A transient disease control rate correlated with donor NK cell expansion, the latter occurring irrespective of IPI. The combination of CIML NK cells with N-803 and IPI was associated with increased early NK cell proliferation, contraction of Treg: Tcon, rapid recovery of recipient CD8+ T cells, and subsequent accelerated rejection of donor NK cells.

CONCLUSIONS

CIML NK cells combined with N-803 and ipilimumab to treat head and neck cancer is safe, and associated with a more proliferative NK cell phenotype. However, the combination leads to reduced HLA mismatched NK cell persistence, resulting in an important limitation affecting NK cell combination therapies in clinical trials. These results inform evaluation of CIML NK therapy for advanced malignancies, with considerations for combination with IPI.

TRIAL REGISTRATION

NCT04290546.

One-carbon metabolism is distinct metabolic signature for proliferative intermediate exhausted T cells of ICB-resistant cancer patients

One-carbon metabolism (1CM) has been reported to promote cancer progression across various malignancies. While 1CM is critical for cell proliferation by enhancing nucleotide synthesis, its physiological roles within different cell types in the tumor immune microenvironment (TIME) still remain unclear. In this study, we analyzed bulk-RNA sequencing and single-cell RNA sequencing (scRNA-seq) data from lung adenocarcinoma (LUAD) patients to elucidate the functional roles of 1CM within the TIME. Moreover, we examined scRNA-seq data from patients treated with immunotherapy across various cancers, including LUAD, glioblastoma, renal cell carcinoma, colorectal cancer, and triple-negative breast cancer. Compared to other cell types, 1CM gene profiles are significantly enriched in a specific subset of T cells. Intriguingly, these high-1CM T cells are identified as proliferative intermediate exhausted T cells (Texint). Furthermore, these proliferative Texint received the most robust CD137 signaling. Consistently, analysis of scRNA-seq data from LUAD patients undergoing anti-PD1 immunotherapy demonstrated that proliferative Texint exhibited higher 1CM scores and increased CD137 signaling. This observation was particularly pronounced in non-responders to immunotherapy, where the Texint population was significantly expanded. We further established that 1CM is a prominent signaling pathway in proliferative Texint in patients resistant to immunotherapy across multiple cancer types. Collectively, we identify CD137 signaling as a distinctive pathway in proliferative Texint of LUAD patients who do not respond to immunotherapy. These findings propose that targeting 1CM may represent a novel therapeutic strategy to enhance the efficacy of immunotherapy by mitigating Texint proliferation in diverse cancers.

Extracellular Vesicle-Based Strategies for Tumor Immunotherapy

Immunotherapy is one of the most promising approaches for cancer management, as it utilizes the intrinsic immune response to target cancer cells. Normally, the human body uses its immune system as a defense mechanism to detect and eliminate foreign objects, including cancer cells. However, cancers develop a 'switch off' mechanism, known as immune checkpoint proteins, to evade immune surveillance and suppress immune activation. Therefore, significant efforts have been made to develop the strategies for stimulating immune responses against cancers. Among these, the use of extracellular vesicles (EVs) to enhance the anti-tumor immune response has emerged as a particularly promising approach in cancer management. EVs possess several unique properties that elevate the potency in modulating immune responses. This review article provides a comprehensive overview of recent advances in this field, focusing on the strategic usage of EVs to overcome tumor-induced immune tolerance. We discuss the biogenesis and characteristics of EVs, as well as their potential applications in medical contexts. The immune mechanisms within the tumor microenvironment and the strategies employed by cancers to evade immune detection are explored. The roles of EVs in regulating the tumor microenvironment and enhancing immune responses for immunotherapy are also highlighted. Additionally, this article addresses the challenges and future directions for the development of EV-based nanomedicine approaches, aiming to improve cancer immunotherapy outcomes with greater precision and efficacy while minimizing off-target effects.

Pretreatment nutritional indices are associated with survival and T-cell exhaustion in recurrent or metastatic oral squamous cell carcinoma patients treated with immune checkpoint inhibitors: a retrospective cohort study

Pretreatment immune dynamics and nutritional status are important predictors of survival outcomes in various malignancies. This study was performed to evaluate the relationships between survival outcomes and the pretreatment nutritional indices - Onodera's prognostic nutritional index (OPNI) and neutrophil-to-lymphocyte ratio (NLR) - in 42 patients with recurrent or metastatic oral squamous cell carcinoma (OSCC) who underwent treatment with immune checkpoint inhibitors (ICI). Additionally, the relationships between these nutritional indices and T-cell exhaustion in the peripheral blood of the patients were analysed. As a result, the Kaplan-Meier method revealed that lower OPNI was significantly associated with poorer overall survival (OS) and progression-free survival (PFS) (both P < 0.001). Likewise, the results of the multivariate analysis showed that a low OPNI was independently associated with poor 5-year OS (hazard ratio 4.36, P = 0.008) and PFS (hazard ratio 4.04, P = 0.010). Patients with a low OPNI had a significantly higher frequency of PD-1+ CD8+ T-cells than those with a high OPNI (P = 0.009). These findings demonstrate that pretreatment OPNI is a valuable independent prognostic indicator of OS and PFS in OSCC patients following treatment with ICI. The OPNI might reflect T-cell exhaustion in the peripheral blood of OSCC patients.

Harnessing extracellular vesicle-mediated crosstalk between T cells and cancer cells for therapeutic applications

Small extracellular vesicles (EVs) are a diverse group of lipid-based particles that are ≤200 nm in diameter and contain an aqueous core. EVs have been shown to mediate intercellular communications between a wide array of immune cells; the downstream effects are diverse and have potential implications for the development of novel immunotherapeutic treatments. Despite a high volume of studies addressing the role EVs play in the immune system, our understanding of the crosstalk between T cells and cancer cells remains limited. Here, we discuss how EVs derived from cancer cells modulate T cell functions and conversely, how T cell derived EVs are crucial in modulating adaptive immune functions. In the context of cancer, tumor derived EVs (TD-EVs) halt T cell-mediated immunity by interfering with effector functions and enhancing regulatory T cell (Treg) functions. In contrast, EVs derived from effector T cells can serve to stimulate anticancer immunity, curbing metastasis and tumor growth. These findings highlight important aspects of how EVs can both mediate the therapeutic effects of T cells as well as impair T cell-mediated immunity. This calls for a deeper understanding of EV-mediated effects in order to advance them as next-generation therapeutics and nanocarriers.

Comprehensive Analysis of Granzymes and Perforin Family Genes in Multiple Cancers

Background/Objectives: Cancer remains a significant global health concern, with immunotherapies emerging as promising treatments. This study explored the role of perforin-1 (PRF1) and granzymes A, B and K (GZMA, GZMB and GZMK) in cancer biology, focusing on their impact on tumor cell death and immune response modulation. Methods: Through a comprehensive genomic analysis across various cancer types, we explored the differential expression, mutation profiles and methylation patterns of these genes, providing insights into their potential as therapeutic targets. Furthermore, we investigated their association with immune cell infiltration and pathway activation within the tumor microenvironment in each tumor type. Results: Our findings revealed distinct expression patterns and prognostic implications for PRF1, GZMA, GZMB and GZMK across different cancers, highlighting their multifaceted roles in tumor immunity. We found increased immune infiltration across all tumor types and significant correlations between the genes of interest and cytotoxic T cells, as well as the most significant survival outcomes in breast cancer. We also show that granzymes and perforin-1 are significantly associated with indicators of immunosuppression and T cell dysfunction within patient cohorts. In skin melanoma, glioblastoma, kidney and bladder cancers, we found significant correlations between the genes of interest and patient survival after receiving immune-checkpoint inhibition therapy. Additionally, we identified potential associations between the mRNA expression levels of these genes and drug sensitivity. Conclusions: Overall, this study enhances our understanding of the molecular mechanisms underlying tumor immunity and provides valuable insights into the potential therapeutic implications of PRF1, GZMA, GZMB and GZMK in cancer treatment.

Brd7 loss reawakens dormant metastasis initiating cells in lung by forging an immunosuppressive niche

Metastasis in cancer is influenced by epigenetic factors. Using an in vivo screen, we demonstrate that several subunits of the polybromo-associated BAF (PBAF) chromatin remodeling complex, particularly Brd7, are required for maintaining breast cancer metastatic dormancy in the lungs of female mice. Brd7 loss induces metastatic reawakening, along with modifications in epigenomic landscapes and upregulated oncogenic signaling. Breast cancer cells harboring Brd7 inactivation also reprogram the surrounding immune microenvironment by downregulating MHC-1 expression and promoting a pro-metastatic cytokine profile. Flow cytometric and single-cell analyses reveal increased levels of pro-tumorigenic inflammatory and transitional neutrophils, CD8+ exhausted T cells, and CD4+ stress response T cells in lungs from female mice harboring Brd7-deficient metastases. Finally, attenuating this immunosuppressive milieu by neutrophil depletion, neutrophil extracellular trap (NET) inhibition, or immune checkpoint therapy abrogates metastatic outgrowth. These findings implicate Brd7 and PBAF in triggering metastatic outgrowth in cancer, pointing to targetable underlying mechanisms involving specific immune cell compartments.

The possible anti-tumor effects of regulatory T cells plasticity / IL-35 in the tumor microenvironment of the major three cancer types

T lymphocytes are among the immunological cells that make up the tumor microenvironment (TME), and they are essential in the growth of tumors and anti-tumor reactions. Regulatory T cells (Treg cells) are a subset of CD4+ T cells in the immune system that suppress the immune system. They are distinguished by their expression of the master transcription factor forkhead box protein P3 (FOXP3). Furthermore, Treg cells are essential for maintaining immunological homeostasis, inhibiting inflammation, and maintaining self-tolerance. In a variety of malignancies within the TME, Treg cells demonstrate notable flexibility and functional diversity. Highly plastic Treg cells can change into Th-like Treg cells in specific circumstances, which allow them to secrete particular pro-inflammatory cytokines. Interleukin 35 (IL-35) is a part of the immunosuppressive cytokines that belong to the IL-12 family. Treg cells release IL-35, which was elevated in the peripheral blood and TME of numerous cancer patients, implying that IL-35 in the TME may be an intriguing target for cancer therapy. In cancer, IL-35 is a two-edged sword; it promotes tumorigenicity in cancer cells while shielding them from apoptosis. Nonetheless, other investigations have mentioned its conflicting effects on cancer prevention. Herein, we provide an updated understanding of the critical mechanisms behind the anticancer immunity mediated by Treg cells plasticity, the role of IL-35, and tactics to strengthen the immune response against malignancies, outlining major clinical trials that used Treg cells/IL-35 therapies in the three main cancer types (lung, breast, and colorectal cancers).

Spatial‒temporal heterogeneities of liver cancer and the discovery of the invasive zone

Solid tumours are intricate and highly heterogeneous ecosystems, which grow in and invade normal organs. Their progression is mediated by cancer cells' interaction with different cell types, such as immune cells, stromal cells and endothelial cells, and with the extracellular matrix. Owing to its high incidence, aggressive growth and resistance to local and systemic treatments, liver cancer has particularly high mortality rates worldwide. In recent decades, spatial heterogeneity has garnered significant attention as an unfavourable biological characteristic of the tumour microenvironment, prompting extensive research into its role in liver tumour development. Advances in spatial omics have facilitated the detailed spatial analysis of cell types, states and cell‒cell interactions, allowing a thorough understanding of the spatial and temporal heterogeneities of tumour microenvironment and informing the development of novel therapeutic approaches. This review illustrates the latest discovery of the invasive zone, and systematically introduced specific macroscopic spatial heterogeneities, pathological spatial heterogeneities and tumour microenvironment heterogeneities of liver cancer.

Immunosenescence and age-related immune cells: causes of age-related diseases

Immunosenescence is a weakening of the immune system due to aging, characterized by changes in immune cells and dysregulated immune function. Age-related immune cells are increasing with aging. They are associated with chronic prolonged inflammation, causing tissue dysfunction and age-related diseases. Here, we discuss increased pro-inflammatory activity of aged macrophages, accumulation of lymphocytes with an age-associated phenotype, and specific alterations in both functions and characteristics of these immune cells. These cellular changes are associated with development of age-related diseases. Additionally, we reviewed various therapeutic strategies targeting age-related immunosenescence, providing pathways to mitigate effects of age-related diseases.

An in-depth understanding of the role and mechanisms of T cells in immune organ aging and age-related diseases

T cells play a critical and irreplaceable role in maintaining overall health. However, their functions undergo alterations as individuals age. It is of utmost importance to comprehend the specific characteristics of T-cell aging, as this knowledge is crucial for gaining deeper insights into the pathogenesis of aging-related diseases and developing effective therapeutic strategies. In this review, we have thoroughly examined the existing studies on the characteristics of immune organ aging. Furthermore, we elucidated the changes and potential mechanisms that occur in T cells during the aging process. Additionally, we have discussed the latest research advancements pertaining to T-cell aging-related diseases. These findings provide a fresh perspective for the study of T cells in the context of aging.

PD-L1-CD80 interactions are required for intracellular signaling necessary for dendritic cell migration

Programmed cell death protein 1 (PD-1) and programmed death ligand 1 (PD-L1) interactions are targets for immunotherapies aimed to reinvigorate T cell function. Recently, it was documented that PD-L1 regulates dendritic cell (DC) migration through intracellular signaling events. In this study, we find that both preclinical murine and clinically available human PD-L1 antibodies limit DC migration. We show that cis interactions between PD-L1 and CD80 are critical for promoting migration and define specific regions within these proteins necessary for migration. Furthermore, we demonstrate that αPD-L1 significantly impedes DC migration in a B16 melanoma tumor model. Last, we outline how blocking cis PD-L1:CD80 interactions or mutation of the intracellular domain of PD-L1, in an imiquimod-induced murine model of psoriasis, limits DC migration to the lymph node, decreases interleukin-17 production by CD4+ T cells in the lymph node, and reduces epidermal thickening. Therefore, PD-L1 and CD80 interactions are important regulators of DC migration to the draining lymph node.

Epithelial cell diversity and immune remodeling in bladder cancer progression: insights from single-cell transcriptomics

BACKGROUND

The progression of bladder cancer (BC) from non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive bladder cancer (MIBC) significantly increases disease severity. Although the tumor microenvironment (TME) plays a pivotal role in this process, the heterogeneity of tumor cells and TME components remains underexplored.

METHODS

We characterized the transcriptomes of single cells from 11 BC samples, including 4 NMIBC, 4 MIBC, and 3 adjacent normal tissues. Bulk RNA-seq data were used to validate the clinical features of characteristic cells, and protein levels of these cells were further confirmed through immunohistochemistry (IHC) and multiplex immunofluorescence.

RESULTS

Bladder cancer progression was associated with distinct transcriptomic features in the TME. Tumor cells in MIBC displayed enhanced glycolytic activity and downregulation of chemokines and MHC-II molecules, reducing immune cell recruitment and facilitating immune evasion. This highlights glycolysis as a potential therapeutic target for disrupting tumor progression. We identified a T cell exhaustion pathway from naive CD8 + T cells (CD8 + TCF7) to terminally exhausted CD8 + STMN1 cells, with progressively declining immune surveillance. Targeting intermediate exhaustion states may restore T cell function and improve anti-tumor immunity. Macrophages polarized toward a pro-tumorigenic phenotype, while VEGFA + mast cells promoted angiogenesis in early-stage BC, suggesting their role as potential targets for therapeutic intervention in NMIBC. Furthermore, conventional dendritic cells (DCs) transformed into LAMP3 + DCs, contributing to an immunosuppressive microenvironment and enabling immune evasion.

CONCLUSION

This study reveals dynamic changes in the TME during BC progression, including enhanced glycolysis, T cell exhaustion, and immune cell remodeling, which contribute to immune evasion and tumor progression. These findings identify critical pathways and cell populations as potential therapeutic targets, offering new strategies to improve treatment outcomes in BC patients.

Progress in personalized immunotherapy for patients with brain metastasis

Brain metastasis leads to poor outcomes and CNS injury, significantly reducing quality of life and survival rates. Advances in understanding the tumor immune microenvironment have revealed the promise of immunotherapies, which, alongside surgery, chemotherapy, and radiation, offer improved survival for some patients. However, resistance to immunotherapy remains a critical challenge. This review explores the immune landscape of brain metastases, current therapies, clinical trials, and the need for personalized, biomarker-driven approaches to optimize outcomes.

Unlocking novel T cell-based immunotherapy for hepatocellular carcinoma through neoantigen-driven T cell receptor isolation

BACKGROUND

Tumour-infiltrating T cells can mediate both antitumour immunity and promote tumour progression by creating an immunosuppressive environment. This dual role is especially relevant in hepatocellular carcinoma (HCC), characterised by a unique microenvironment and limited success with current immunotherapy.

OBJECTIVE

We evaluated T cell responses in patients with advanced HCC by analysing tumours, liver flushes and liver-draining lymph nodes, to understand whether reactive T cell populations could be identified despite the immunosuppressive environment.

DESIGN

T cells isolated from clinical samples were tested for reactivity against predicted neoantigens. Single-cell RNA sequencing was employed to evaluate the transcriptomic and proteomic profiles of antigen-experienced T cells. Neoantigen-reactive T cells expressing 4-1BB were isolated and characterised through T-cell receptor (TCR)-sequencing.

RESULTS

Bioinformatic analysis identified 542 candidate neoantigens from seven patients. Of these, 78 neoantigens, along with 11 hotspot targets from HCC driver oncogenes, were selected for ex vivo T cell stimulation. Reactivity was confirmed in co-culture assays for 14 targets, with most reactive T cells derived from liver flushes and lymph nodes. Liver flush-derived T cells exhibited central memory and effector memory CD4+ with cytotoxic effector profiles. In contrast, tissue-resident memory CD4+ and CD8+ T cells with an exhausted profile were primarily identified in the draining lymph nodes.

CONCLUSION

These findings offer valuable insights into the functional profiles of neoantigen-reactive T cells within and surrounding the HCC microenvironment. T cells isolated from liver flushes and tumour-draining lymph nodes may serve as a promising source of reactive T cells and TCRs for further use in immunotherapy for HCC.

Microenvironmental β-TrCP negates amino acid transport to trigger CD8+ T cell exhaustion in human non-small cell lung cancer

CD8+ T cell exhaustion (Tex) has been widely acknowledged in human cancer, while the underlying mechanisms remain unclear. Here, we demonstrate that reduced amino acid (aa) metabolism and mTOR inactivation are accountable for Tex in human non-small cell lung cancer (NSCLC). NSCLC cells impede the T cell-intrinsic transcription of SLC7A5 and SLC38A1, disrupting aa transport and consequently leading to mTOR inactivation. Further, the ubiquitination of YAP1 protein is the basis for NSCLC-mediated transcriptional inhibition of aa transporters. Mechanistically, NSCLC cells transfer β-TrCP-containing exosomes into T cells, inducing YAP1 ubiquitination and Tex. Consequently, inhibiting cancer-associated β-TrCP effectively restores the anti-tumor immune response of CD8+ T cells and curtails tumor growth in NSCLC patient-derived organoids. Together, our findings highlight a β-TrCP-dependent mechanism in steering intrinsic metabolic adaptation and CD8+ Tex, emphasizing microenvironmental β-TrCP as an immune checkpoint for therapeutic exploration against human NSCLC.

A review of innovative design strategies: Artificial antigen presenting cells in cancer immunotherapy

Developing nanocarriers that can carry medications directly to tumors is an exciting development in cancer nanomedicine. The efficacy of this intriguing therapeutic approach is, however, compromised by intricate and immunosuppressive circumstances that arise concurrently with the onset of cancer. The artificial antigen presenting cell (aAPC), a micro or nanoparticle based device that mimics an antigen presenting cell by providing crucial signal proteins to T lymphocytes to activate them against cancer, is one cutting-edge method for cancer immunotherapy. This review delves into the critical design considerations for aAPCs, particularly focusing on particle size, shape, and the non-uniform distribution of T cell activating proteins on their surfaces. Adequate surface contact between T cells and aAPCs is essential for activation, prompting engineers to develop nano-aAPCs with microscale contact areas through techniques such as shape modification and nanoparticle clustering. Additionally, we explore recommendations for future advancements in this field.

Investigating T Cell Immune Dynamics and IL-6's Duality in a Microfluidic Lung Tumor Model

Interleukin 6 (IL-6), produced by immune cells, is crucial in promoting T cell trafficking to infection and inflammation sites, influencing various physiological and pathological processes. Concentrations of IL-6 and other cytokines and chemokines can influence T cell differentiation and activation. Understanding the dual faces of IL-6 within the tumor microenvironment is crucial to understanding its role. A flow-based microsystem was designed to investigate CD4+ T cell activation in response to different IL-6 gradients in an under-control 3D culture. The study found that cancer cells' response to varying IL-6 concentrations was dynamic and dose-sensitive, with immune cell migration rates showing sensitivity to the IL-6 gradient. A549 cell expansion increases gradually and time-dependently with 50 ng of IL-6, while Jurkat cell migration follows a time-dependent pattern. However, when a total of 100 ng IL-6 concentration is applied, A549 cells expand rapidly, potentially influencing Jurkat cell migration. Jurkat cell mobility is lower, possibly due to increased A549 cell presence and heightened cell-cell interactions. Different IL-6 concentration gradients can modulate the expression of some CD markers like CD69 and programed cell death protein 1 in CD4+ T cells, suggesting that IL-6 concentration gradients affect immune cell phenotypes. This suggests that IL-6 plays a crucial role in activating T helper cells and may be involved in the later phases of inflammation. Also, the increased levels of IFN-γ and TNF-α highlight IL-6's impact on T cell inflammatory response. This study emphasizes the intricate effects of IL-6 on T cell activation, phenotype, cytokine production, and phenotypic heterogeneity, providing valuable insights into immune response modulation in an experimental setting.

Advances in nucleic acid-based cancer vaccines

Nucleic acid vaccines have emerged as crucial advancements in vaccine technology, particularly highlighted by the global response to the COVID-19 pandemic. The widespread administration of mRNA vaccines against COVID-19 to billions globally marks a significant milestone. Furthermore, the approval of an mRNA vaccine for Respiratory Syncytial Virus (RSV) this year underscores the versatility of this technology. In oncology, the combination of mRNA vaccine encoding neoantigens and immune checkpoint inhibitors (ICIs) has shown remarkable efficacy in eliciting protective responses against diseases like melanoma and pancreatic cancer. Although the use of a COVID-19 DNA vaccine has been limited to India, the inherent stability at room temperature and cost-effectiveness of DNA vaccines present a viable option that could benefit developing countries. These advantages may help DNA vaccines address some of the challenges associated with mRNA vaccines. Currently, several trials are exploring the use of DNA-encoded neoantigens in combination with ICIs across various cancer types. These studies highlight the promising role of nucleic acid-based vaccines as the next generation of immunotherapeutic agents in cancer treatment. This review will delve into the recent advancements and current developmental status of both mRNA and DNA-based cancer vaccines.

The tumor immune microenvironment in primary cutaneous melanoma

Melanoma is an immunogenic tumor. The melanoma tumor immune microenvironment (TIME) is made up of a heterogenous mix of both immune and non-immune cells as well as a multitude of signaling molecules. The interactions between tumor cells, immune cells and signaling molecules affect tumor progression and therapeutic responses. Understanding the composition and function of the TIME in primary cutaneous melanoma is useful for prognostication and therapeutic decisions. This review provides an overview of the components of the TIME in primary cutaneous melanoma, and their influence on clinical outcomes.

Transcriptional signature of CD56bright NK cells predicts favourable prognosis in bladder cancer

Human natural killer (NK) cells can be sub-divided into two functional subsets but the clinical significance of these CD56bright and CD56dim NK cells in anti-tumour immunity remains largely unexplored. We determined the relative abundances of gene signatures for CD56bright and CD56dim NK cells along with 3 stromal and 18 other immune cell types in the patient tumour transcriptomes from the cancer genome atlas bladder cancer dataset (TCGA-BLCA). Using this computational approach, CD56bright NK cells were predicted to be the more abundant tumour-infiltrating NK subset which was also associated with improved patient prognosis. A similar favorable survival trend was projected using gene signatures for mature myeloid dendritic cells (mDC) and CD8+ effector memory T cells (TEM) and unveiled a potential CD56bright NK-mDC-CD8+T cell crosstalk in the BLCA tumour microenvironment. Expression of transcripts encoding the activating NK cell receptors, NKG2D, NKp44, CD2, and CD160, showed positive survival trends in combination with CD56bright NK cell infiltration. Transcription factors including HOBIT, IRF3, and STAT2 were also correlated with CD56bright NK cell abundance. Additionally, a HOBIT-dependent tissue-residency program correlated with the CD56bright NK and CD8+ TEM cell signatures was found to be associated with favourable BLCA patient survival. Overall, our study highlights the significance of CD56bright NK cells in BLCA patient prognosis. Our findings facilitate a better understanding of the NK cell anti-tumour responses that may ultimately lead to the development of promising NK and T cell-based therapies for BLCA.

Prognostic immune markers in esophageal cancer patients managed with trimodal therapy

BACKGROUND

Esophageal cancer (ESC) is an aggressive disease which often presents at an advanced stage. Despite trimodal therapy, 40-50% patients can develop metastatic disease by 18 months. Identification of patients at risk for metastatic spread is challenging with need for improved prognostication. We investigated whether the immune landscape of pretreatment tissue was associated with relapse in ESC patients.

METHODS

Between April 2010 and October 2018, we identified 25 patients who had undergone trimodal therapy for ESC and had pretreatment biopsies suitable for analyses. We performed high-throughput multispectral immunofluorescence (mIF) analysis on formalin-fixed paraffin embedded biopsy samples. Analysis of 27 unique populations via immune and exhaustion mIF panels was performed and expression was normalized to total cell counts.

RESULTS

Of the 25 patients analyzed, the median follow-up time was 23.9 months, during which 12 (48%) patients suffered a relapse with a median time to progression of 13.1 months. mIF revealed higher expression of HLA-DR (p = 0.019), CD8/LAG3 (p = 0.046), and CD8/CTLA4 (p = 0.027) among patients without relapse. Time to progression (TTP) and disease-specific survival (DSS) were stratified by median expression of each significant subpopulation and formally tested by the log-rank test. Higher than median expression of HLA-DR (p = 0.027), CD8/LAG3 (p = 0.039), and CD8/CTLA4 (p = 0.039) were significantly associated with TTP. Similarly, HLA-DR (p = 0.0069) and CD8/CTLA4 (p = 0.036) were significantly associated with improved DSS, whereas no significant observations were found with CD8/LAG3 (p = 0.11) expression. Stromal, but not tumoral expression of CD163 and CD163/PDL1 were significantly associated with improved TTP and DSS.

CONCLUSIONS

High expression of HLA-DR, CD8/CTLA4, and stromal expression of CD163 and CD163/PDL1 within pretreatment biopsy ESC samples was associated with significantly reduced rates of relapse. Increased presence of these markers suggests that an improved immune landscape is associated with less aggressive disease and may provide an opportunity for risk-based treatment strategies.

Expression pattern of cancer-associated cellular senescence genes in clear cell renal cell carcinoma distinguishes tumor subclasses with clinical implications

Clear cell renal cell carcinoma (ccRCC) is a highly lethal subtype of renal cancer. Accumulating evidence suggests cellular senescence impacts tumor development and progression. This study aimed to identify ccRCC subtypes based on a cellular senescence gene signature and assess their clinical relevance. Using hierarchical clustering on the TCGA-KIRC dataset, two senescence-related subtypes were identified and validated in independent datasets. These subtypes exhibited distinct dysregulation of cancer-related pathways, including the p53 pathway. The C2 subtype was associated with poorer overall survival, higher tumor grade and stage, low hemoglobin, and elevated platelet and serum calcium levels. Patients with the C2 subtype also had lower endothelial cell infiltration, indicating reduced benefit from anti-PD-1 immunotherapy. A nomogram based on these subtypes effectively predicted 1-, 3-, and 5-year survival outcomes. These findings highlight two distinct senescence-related ccRCC subtypes that correlate with prognosis and therapy response, offering insights for personalized treatment strategies.

PVR exposure influences the activation, adhesion, and protein expression of human CD8+ T cells, including the CD96-mediated transfer of PVR

Poliovirus receptor (PVR) ligands have gained attention as immunotherapy targets, yet their regulation remains unclear. Here, we examine the impact of PVR exposure on primary human CD8+ T cells. We used flow cytometry and Western blot analysis to quantify expression of PVR and its ligands in naïve and effector T cells and used adhesion assays and enzyme-linked immunosorbent assay (ELISA) to assess the impact of PVR on T cell adhesion and cytokine production. Stimulation with phytohemagglutinin P strongly increased DNAM-1 expression and caused a less robust and more variable increase in TIGIT expression. Exposure to PVR-Fc enhanced the CD8+ T cell adhesion to ICAM-1-coated plates in a dose-dependent manner, while exposure to PVR-expressing K32 cells mildly decreased CD8+ T cell interferon γ release. However, PVR exposure strongly decreased the expression of DNAM-1, TIGIT, and CD96. The reduction of DNAM-1, TIGIT, and CD96 induced by PVR was dominant to the increase caused by T cell receptor signaling. The impact of PVR on their expression was completely abolished by the Q63R and F128R point mutations of PVR, while DNAM-1 was partially rescued by inhibitors of Src and protein kinase C. Additionally, PVR exposure along with T cell receptor signaling promoted the transfer of surface proteins including PVR from K32 cells to CD8+ T cells. This PVR transfer was mediated by the IgV domain of PVR and CD96 on CD8+ T cells and required cellular contact. Our findings collectively demonstrate that PVR engagement has a mild antagonistic effect on interferon γ production but strongly impacts CD8+ T cell adhesion and protein expression.

Inhibition of Glutamate-to-Glutathione Flux Promotes Tumor Antigen Presentation in Colorectal Cancer Cells

Colorectal cancer (CRC) cells display remarkable adaptability, orchestrating metabolic changes that confer growth advantages, pro-tumor microenvironment, and therapeutic resistance. One such metabolic change occurs in glutamine metabolism. Colorectal tumors with high glutaminase (GLS) expression exhibited reduced T cell infiltration and cytotoxicity, leading to poor clinical outcomes. However, depletion of GLS in CRC cells has minimal effect on tumor growth in immunocompromised mice. By contrast, remarkable inhibition of tumor growth is observed in immunocompetent mice when GLS is knocked down. It is found that GLS knockdown in CRC cells enhanced the cytotoxicity of tumor-specific T cells. Furthermore, the single-cell flux estimation analysis (scFEA) of glutamine metabolism revealed that glutamate-to-glutathione (Glu-GSH) flux, downstream of GLS, rather than Glu-to-2-oxoglutarate flux plays a key role in regulating the immune response of CRC cells in the tumor. Mechanistically, inhibition of the Glu-GSH flux activated reactive oxygen species (ROS)-related signaling pathways in tumor cells, thereby increasing the tumor immunogenicity by promoting the activity of the immunoproteasome. The combinatorial therapy of Glu-GSH flux inhibitor and anti-PD-1 antibody exhibited a superior tumor growth inhibitory effect compared to either monotherapy. Taken together, the study provides the first evidence pointing to Glu-GSH flux as a potential therapeutic target for CRC immunotherapy.

Tumor microenvironment in primary central nervous system lymphoma (PCNSL)

Primary central nervous system lymphoma (PCNSL) is one of the rare lymphomas limited to the central nervous system. With the availability of immunotherapy, the tumor microenvironment (TME) attracts much attention nowadays. However, the systematic studies on the TME of PCNSL are lacking. By reviewing the existing research, we found that the TME of PCNSL is infiltrated with abundant TAMs and TILs, among which cytotoxic T cells (CTLs) and M2-polarized macrophages are principal. However, the counts of immune cells infiltrated in the TME of PCNSL are significantly lower than systemic diffuse large B-cell lymphoma (DLBCL). In addition, PCNSL can attract the infiltration of immunosuppressive cells and the loss of HLA I/II expression, overexpress inhibitory immune checkpoints, and release immunosuppressive cytokines to form an immunosuppressive TME. The immunosuppressive effect of TME in PCNSL is significantly stronger than that in systemic DLBCL. These characteristics of TME highlight the immunosuppression of PCNSL.

Cancer vaccines: an update on recent achievements and prospects for cancer therapy

Decades of basic and translational research have led to a momentum shift in dissecting the relationship between immune cells and cancer. This culminated in the emergence of breakthrough immunotherapies that paved the way for oncologists to manage certain hard-to-treat cancers. The application of high-throughput techniques of genomics, transcriptomics, and proteomics was conclusive in making and expediting the manufacturing process of cancer vaccines. Using the latest research technologies has also enabled scientists to interpret complex and multiomics data of the tumour mutanome, thus identifying new tumour-specific antigens to design new generations of cancer vaccines with high specificity and long-term efficacy. Furthermore, combinatorial regimens of cancer vaccines with immune checkpoint inhibitors have offered new therapeutic approaches and demonstrated impressive efficacy in cancer patients over the last few years. In the present review, we summarize the current state of cancer vaccines, including their potential therapeutic effects and the limitations that hinder their effectiveness. We highlight the current efforts to mitigate these limitations and highlight ongoing clinical trials. Finally, a special focus will be given to the latest milestones expected to transform the landscape of cancer therapy and nurture hope among cancer patients.

Patterns of immune evasion in triple-negative breast cancer and new potential therapeutic targets: a review

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer characterized by the absence of progesterone and estrogen receptors and low (or absent) HER2 expression. TNBC accounts for 15-20% of all breast cancers. It is associated with younger age, a higher mutational burden, and an increased risk of recurrence and mortality. Standard treatment for TNBC primarily relies on cytotoxic agents, such as taxanes, anthracyclines, and platinum compounds for both early and advanced stages of the disease. Several targeted therapies, including bevacizumab and sunitinib, have failed to demonstrate significant clinical benefit in TNBC. The emergence of immune checkpoint inhibitors (ICI) has revolutionized cancer treatment. By stimulating the immune system, ICIs induce a durable anti-tumor response across various solid tumors. TNBC is a particularly promising target for treatment with ICIs due to the higher levels of tumor-infiltrating lymphocytes (TIL), increased PD-L1 expression, and higher mutational burden, which generates tumor-specific neoantigens that activate immune cells. ICIs administered as monotherapy in advanced TNBC yields only a modest response; however, response rates significantly improve when ICIs are combined with cytotoxic agents, particularly in tumors expressing PD-L1. Pembrolizumab is approved for use in both early and advanced TNBC in combination with standard chemotherapy. However, more research is needed to identify more potent biomarkers, and to better elucidate the synergism of ICIs with other targeted agents. In this review, we explore the challenges of immunotherapy in TNBC, examining the mechanisms of tumor progression mediated by immune cells within the tumor microenvironment, and the signaling pathways involved in both primary and acquired resistance. Finally, we provide a comprehensive overview of ongoing clinical trials underway to investigate novel immune-targeted therapies for TNBC.

p53: The Multifaceted Roles of Covalent Modifications in Cancer

The p53 protein has attracted huge research interest over several decades due to its role as one of the most important tumor suppressors in mammals, which orchestrates a synchronous response from normal cells in the body to various forms of stress. The diverse cellular activities of the p53 protein are regulated mainly via its post-translational modifications (PTMs). PTMs affect p53 on several levels: at the level of the assembly of tetrameric complexes on DNA to transactivate its target genes, at the level of the assembly of tetrameric complexes on DNA to transactivate its target genes; at the level of proteolysis in the absence of stress; and on the contrary, at the level of augmented protein stability in response to stress signals. Disruptions in these regulatory mechanisms can lead to deviations from normal cellular function, boosting tumor initiation and progression. Conversely, targeted interventions in these pathways could prove beneficial for the development of antitumor therapies. Advancing our understanding of p53 modifiers and the proteins involved in its regulation equips researchers with an expanded toolkit for studying cellular processes and for developing biologically active molecules that influence p53-mediated responses.

IRGQ-mediated autophagy in MHC class I quality control promotes tumor immune evasion

The autophagy-lysosome system directs the degradation of a wide variety of cargo and is also involved in tumor progression. Here, we show that the immunity-related GTPase family Q protein (IRGQ), an uncharacterized protein to date, acts in the quality control of major histocompatibility complex class I (MHC class I) molecules. IRGQ directs misfolded MHC class I toward lysosomal degradation through its binding mode to GABARAPL2 and LC3B. In the absence of IRGQ, free MHC class I heavy chains do not only accumulate in the cell but are also transported to the cell surface, thereby promoting an immune response. Mice and human patients suffering from hepatocellular carcinoma show improved survival rates with reduced IRGQ levels due to increased reactivity of CD8+ T cells toward IRGQ knockout tumor cells. Thus, we reveal IRGQ as a regulator of MHC class I quality control, mediating tumor immune evasion.

Integrating IL-12 mRNA nanotechnology with SBRT eliminates T cell exhaustion in preclinical models of pancreatic cancer

Pronounced T cell exhaustion characterizes immunosuppressive tumors, with the tumor microenvironment (TME) employing multiple mechanisms to elicit this suppression. Traditional immunotherapies, such as immune checkpoint blockade, often fail due to their focus primarily on T cells. To overcome this, we utilized a proinflammatory cytokine, interleukin (IL)-12, that re-wires the immunosuppressive TME by inducing T cell effector function while also repolarizing immunosuppressive myeloid cells. Due to toxicities observed with systemic administration of this cytokine, we utilized lipid nanoparticles encapsulating mRNA encoding IL-12 for intratumoral injection. This strategy has been proven safe and tolerable in early clinical trials for solid malignancies. We report an unprecedented loss of exhausted T cells and the emergence of an activated phenotype in murine pancreatic ductal adenocarcinoma (PDAC) treated with stereotactic body radiation therapy (SBRT) and IL-12mRNA. Our mechanistic findings reveal that each treatment modality contributes to the T cell response differently, with SBRT expanding the T cell receptor repertoire and IL-12mRNA promoting robust T cell proliferation and effector status. This distinctive T cell signature mediated marked growth reductions and long-term survival in local and metastatic PDAC models. This is the first study of its kind combining SBRT with IL-12mRNA and provides a promising new approach for treating this aggressive malignancy.

Targeting CD4+ T cell Exhaustion to Improve Future Immunotherapy Strategies

As of late, reinvigoration of exhausted T cells as a form of immunotherapy against cancer has been a promising strategy. However, inconsistent results highlight the uncertainties in the current understanding of cellular exhaustion and the need for research and better treatment design. In our previous work, we utilized mathematical modeling and analysis to recapitulate and complement the biological understanding of exhaustion in response to growing tumors. The results of this work recognized that the population size of progenitor exhausted CD8+ T cells played a larger factor in tumor control compared to cytotoxic abilities. From this notion, it was theorized that exhaustion in CD4+ T cells, which are known to help coordinate and promote the size of the CD8+ T cell response, would be a significant component of tumor control. To test this theory, this paper expands on the previous mathematical framework by incorporating CD4+ T cells and the exhaustion they face in response to tumoral settings. Analysis of this model supports our theory, indicating that targeting CD4+ T cell exhaustion would have a potentially large impact on tumor burden and should be investigated along with current immunotherapy strategies of exhausted CD8+ T cell reinvigoration. Ultimately, this work narrows the scope of future research, providing a potential target for improved therapeutic efforts.

Viscoelastic synthetic antigen-presenting cells for augmenting the potency of cancer therapies

The use of synthetic antigen-presenting cells to activate and expand engineered T cells for the treatment of cancers typically results in therapies that are suboptimal in effectiveness and durability. Here we describe a high-throughput microfluidic system for the fabrication of synthetic cells mimicking the viscoelastic and T-cell-activation properties of antigen-presenting cells. Compared with rigid or elastic microspheres, the synthetic viscoelastic T-cell-activating cells (SynVACs) led to substantial enhancements in the expansion of human CD8+ T cells and to the suppression of the formation of regulatory T cells. Notably, activating and expanding chimaeric antigen receptor (CAR) T cells with SynVACs led to a CAR-transduction efficiency of approximately 90% and to substantial increases in T memory stem cells. The engineered CAR T cells eliminated tumour cells in a mouse model of human lymphoma, suppressed tumour growth in mice with human ovarian cancer xenografts, persisted for longer periods and reduced tumour-recurrence risk. Our findings underscore the crucial roles of viscoelasticity in T-cell engineering and highlight the utility of SynVACs in cancer therapy.

Chemotherapy-induced acceleration of DNA methylation-based biological age in breast cancer

Breast cancer is the most common cancer diagnosed in women and is often treated with chemotherapy. Although previous studies have demonstrated increasing biological age in patients who receive chemotherapy, evaluation of this association with DNA methylation-based markers of biological ageing may provide novel insight into the role of chemotherapy on the ageing process. We therefore sought to investigate the association between chemotherapy and markers of biological ageing as estimated from DNA methylation in women with breast cancer. DNA methylation profiling was performed on peripheral blood collected from 18 patients before and after the first cycle of chemotherapy using the Infinium HumanMethylation450 BeadChip. Six markers of biological age acceleration were estimated from DNA methylation levels. Multiple linear regression analyses were performed to evaluate the association between each metric of biological age acceleration and chemotherapy. After adjusting for chronological age and race, intrinsic epigenetic age acceleration (p = 0.041), extrinsic epigenetic age acceleration (p = 0.050), PhenoAge acceleration (p = 0.001), GrimAge acceleration (p < 0.001), and DunedinPACE (p = 0.006) were significantly higher and telomere length (p = 0.027) was significantly lower following the first cycle of chemotherapy compared to before treatment initiation. These results demonstrate greater biological ageing as estimated from DNA methylation following chemotherapy in women with breast cancer. Our findings illustrate that cytotoxic therapies may modulate the ageing process among breast cancer patients and may also have implications for age-related health conditions in cancer survivors.