Intratumoral CD8+ T-cell Apoptosis Is a Major Component of T-cell Dysfunction and Impedes Antitumor Immunity

Causes and consequences of T cell DNA damage

Although DNA damage is a common cellular event, T cells experience significant genotoxic stresses because of rapid antigen-stimulated expansion and their presence in various nonlymphoid microenvironments. In addition to the well-established link between genomic instability and malignancy, recent genomic studies have uncovered a substantial mutational burden in nonmalignant T cells in both normal aging and disease contexts. Furthermore, genomic damage in T cells is accelerated in autoimmune diseases and in older individuals because of both intrinsic and extrinsic factors. This review highlights the different genotoxic stressors affecting T cells and the detrimental effects of persistent DNA damage and identifies the most critical knowledge gaps.

Resistance to PD-1/PD-L1 immune checkpoint blockade in advanced non-small cell lung cancer

Lung cancer is one of the most common malignant tumors, of which non-small cell lung cancer (NSCLC) accounts for about 85 %. Although immune checkpoint inhibitors (ICIs), particularly PD-1/PD-L1 inhibitors, have significantly improved the prognosis of patients with NSCLC. There are still many patients do not benefit from ICIs. Primary resistance remains a major challenge in advanced NSCLC. The cancer-immunity cycle describes the process from antigen release to T cell recognition and killing of the tumor, which provides a framework for understanding anti-tumor immunity. The classical cycle consists of seven steps, and alterations at each stage can result in resistance. This review examines the current status of PD-1/PD-L1 blockade in the treatment of advanced NSCLC and explores potential mechanisms of resistance. We summarize the latest clinical trials of PD-1/PD-L1 inhibitors combined with other therapies and explore potential targets for overcoming primary resistance to PD-1/PD-L1 inhibitors.

Acasunlimab, an Fc-inert PD-L1×4-1BB bispecific antibody, combined with PD-1 blockade potentiates antitumor immunity via complementary immune modulatory effects

BACKGROUND

Next-generation cancer immunotherapies aim to improve patient outcomes by combining inhibitory signal blockade with targeted T-cell costimulation in tumor and lymphoid tissues. Acasunlimab (DuoBody-PD-L1×4-1BB) is an investigational, bispecific antibody designed to elicit an antitumor immune response via conditional 4-1BB activation strictly dependent on simultaneous programmed death-ligand 1 (PD-L1) binding. Since 4-1BB is coexpressed with programmed cell death protein-1 (PD-1) on CD8+ T cells, PD-1 blockade and simultaneous costimulation through 4-1BB may synergistically enhance T-cell effector functions. We hypothesized that combining acasunlimab with PD-1 blockade to fully disrupt PD-1 interactions with both PD-L1 and PD-L2 would amplify the depth and duration of antitumor immunity.

METHODS

The effect of acasunlimab and pembrolizumab combination was analyzed in vitro using functional immune cell assays, including mixed-lymphocyte reactions and antigen-specific T-cell proliferation and cytotoxicity assays. The antitumor activity of the combination was tested in vivo in (1) MC38, MB49, Pan02, and B16F10 syngeneic tumor models using acasunlimab and anti-PD-1 mouse-surrogate antibodies; and (2) triple knock-in mice expressing the human targets using an acasunlimab chimeric antibody (chi-acasunlimab) and pembrolizumab. The mechanism of action of the combination was investigated in the MC38 syngeneic model through immunohistochemistry, flow cytometry, and bulk RNA sequencing.

RESULTS

The combination reinvigorated dysfunctional T cells in vitro, while also potentiating T-cell expansion, interleukin (IL)-2 and interferon gamma secretion and cytotoxic activity. In vivo, the combination of chi-acasunlimab and pembrolizumab or mouse-surrogate antibodies potentiated antitumor activity and survival in the humanized knock-in and multiple syngeneic mouse models, leading to durable complete tumor regressions in the MC38 model consistent with therapeutic synergy. Mechanistically, the combination enhanced clonal expansion of tumor-specific CD8+ T cells in tumor-draining lymph nodes and increased the density of proliferating and cytotoxic CD8+ T cells in the tumor microenvironment. It also potentiated the IL-2 signaling pathway, increasing the proportion of granzyme B (GZMB+) stem-like CD8+ T cells thought to have superior effector function.

CONCLUSION

These preclinical results demonstrate that conditional 4-1BB stimulation combined with complete PD-1 blockade enhances antitumor immunity through complementary mechanisms. The acasunlimab and pembrolizumab combination is being evaluated in Phase 2 (NCT05117242) and pivotal Phase 3 (NCT06635824) trials in patients with metastatic non-small cell lung cancer after checkpoint inhibitor therapy failure.

Immunogenic cell death genes in single-cell and transcriptome analyses perspectives from a prognostic model of cervical cancer

Background

The role of immunogenic cell death (ICD) in cervical cancer (CESC) is not well understood. This study sought to investigate the significance of ICD in CESC and to establish an ICDRs prognostic model to improve immunotherapy efficacy for patients with cervical cancer.

Methods

ICD-associated genes were screened at the single-cell and transcriptome levels based on AddModuleScore, single-sample gene set enrichment analysis (ssGSEA) and weighted gene co-expression network (WGCNA) analysis. Immunogenic cell death-related features (ICDRs) were constructed using multiple machine algorithms, and ICDRs were evaluated in training and validation sets to provide quantitative tools for predicting prognosis in clinical practice. Predictive models were used to risk subgroups for response to immunotherapy, as well as drug sensitivity. Finally, the expression of ICD-related genes was verified by RT-qPCR.

Results

Through an integrated analysis of single-cell data, transcriptomic profiling, and computational modeling, seven ICD-related genes were identified as highly prognostic for CESC patients. Multivariate analysis demonstrated that low-risk patients had significantly better overall survival compared to high-risk patients, confirming the model as an independent prognostic tool. Assessments of the tumor microenvironment (TME), mutation characteristics, and drug sensitivity within ICDRs risk subgroups indicated a stronger immunotherapy response in the low-risk group.

Lung Cancer-Intrinsic SOX2 Expression Mediates Resistance to Checkpoint Blockade Therapy by Inducing Treg-Dependent CD8+ T-cell Exclusion

Tumor cell-intrinsic signaling pathways can drastically affect the tumor immune microenvironment, promoting tumor progression and resistance to immunotherapy by excluding immune cell populations from the tumor. Several tumor cell-intrinsic pathways have been reported to modulate myeloid-cell and T-cell infiltration, creating "cold" tumors. However, clinical evidence suggests that excluding cytotoxic T cells from the tumor core also mediates immune evasion. In this study, we find that tumor cell-intrinsic SOX2 signaling in non-small cell lung cancer induces the exclusion of cytotoxic T cells from the tumor core and promotes resistance to checkpoint blockade therapy. Mechanistically, tumor cell-intrinsic SOX2 expression upregulates CCL2 in tumor cells, resulting in increased recruitment of regulatory T cells (Treg). CD8+ T-cell exclusion depended on Treg-mediated suppression of tumor vasculature. Depleting tumor-infiltrating Tregs via glucocorticoid-induced TNF receptor-related protein restored CD8+ T-cell infiltration and, when combined with checkpoint blockade therapy, reduced tumor growth. These results show that tumor cell-intrinsic SOX2 expression in lung cancer serves as a mechanism of immunotherapy resistance and provide evidence to support future studies investigating whether patients with non-small cell lung cancer with SOX2-dependent CD8+ T-cell exclusion would benefit from the depletion of glucocorticoid-induced TNFR-related protein-positive Tregs.

Enhancing anti-CD3 mAb-mediated diabetes remission in autoimmune diabetes through regulation of dynamin-related protein 1(Drp1)-mediated mitochondrial dynamics in exhausted CD8+T-cell subpopulations

BACKGROUND

Antigen-specific immunotherapy shows potential for inducing long-term immune tolerance in type 1 diabetes (T1D), yet its clinical application is hampered by uncertainty regarding dominant epitopes. Conversely, non-antigen-specific treatments such as anti-CD3 monoclonal antibodies (mAbs) present a more straightforward approach but struggle to maintain tolerance after treatment. Addressing these issues is critical for advancing T1D therapies.

METHODS

The phenotypic and metabolic properties of two subsets of exhausted CD8+ T cells were analyzed in both humans and NOD mice. T-cell receptor (TCR) diversity and Bulk RNA sequencing provided insights into the transcriptomic profiles and TCR reactivity of these cells. Mechanistic studies were conducted using the HEK-293 T cell line and primary cells. Single-cell RNA sequencing (scRNA-seq) was applied to evaluate the characteristics of different CD8+ T cell subsets following two types of immunotherapies. In NY8.3 mice, the effect of mitochondrial fission inhibitors on immunotherapy results was evaluated. Final validation was carried out with peripheral blood mononuclear cells (PBMCs) from T1D patients.

RESULTS

Our study reveals the diversity of two distinct exhausted CD8+ T cell subsets in T1D through flow cytometry, highlighting unique clinical features, phenotypes, and functions. Notable differences in TCR reactivity and metabolic pathways between these subsets were identified through TCR sequencing and transcriptomic analyses in NOD mice. Both antigen-specific and non-antigen-specific stimuli produced unique exhausted CD8+ T cell subsets. Our research identified leucine-rich repeat kinase 2 (Lrrk2) as a key regulator of mitochondrial fission, influencing the interconversion of exhausted CD8+ T cell subsets by phosphorylating dynamin-related protein 1 (DRP1) at serine 637 (Ser637) and serine 616 (Ser616). scRNA-seq confirmed that antigen-specific immunotherapy effectively suppresses T cell signaling, induces exhaustion, and promotes the development of terminally exhausted T (TEX) cells. Mitochondrial division inhibitor 1 (Mdivi-1) enhanced the therapeutic effect of anti-CD3 mAb treatment by promoting the development of more TEX cells.

CONCLUSIONS

Our results point to a new immunotherapeutic approach that targets exhausted CD8+ T cells' energy metabolism, offering valuable insights for advancing clinical strategies in T1D therapy.

Macrophage-derived Fgl2 dampens antitumor immunity through regulation of FcγRIIB+CD8+ T cells in melanoma

Cancer immunotherapy has emerged as a promising therapeutic modality but heterogeneity in patient responsiveness remains. Thus, greater understanding of the immunologic factors that dictate response to immunotherapy is critical to improve patient outcomes. Here, we show that fibrinogen-like protein 2 (Fgl2) is elevated in the setting of melanoma in humans and mice and plays a functional role in inhibiting the CD8+ T cell response. Surprisingly, the tumor itself is not the major cellular source of Fgl2. Instead, we found that macrophage-secreted Fgl2 dampens the CD8+ T cell response through binding and apoptosis of FcγRIIB+CD8+ T cells. This regulation was CD8+ T cell autonomous and not via an antigen-presenting cell intermediary, as absence of Fcgr2b from the CD8+ T cells rendered T cells insensitive to Fgl2 regulation. Fgl2 is robustly expressed by macrophages in 10 cancer types in humans and in 6 syngeneic tumor models in mice, underscoring the clinical relevance of Fgl2 as a therapeutic target to promote T cell activity and improve patient immunotherapeutic response.

T lymphocyte-based immune response and therapy in hepatocellular carcinoma: focus on TILs and CAR-T cells

Hepatocellular carcinoma (HCC) is among the leading causes of cancer-related death worldwide. The primary therapies for HCC are liver transplantation, hepatic tumor excision, radiofrequency ablation, and molecular-targeted medicines. An unfavorable prognosis marks HCC and has limited pharmacological response in therapeutic studies. The tumor immune microenvironment (TME) imposes significant selection pressure on HCC, resulting in its evolution and recurrence after various treatments. As the principal cellular constituents of tumor-infiltrating lymphocytes (TILs), T cells have shown both anti-tumor and protumor actions in HCC. T cell-mediated immune responses are pivotal in cancer monitoring and elimination. TILs are recognized for their critical involvement in the progression, prognosis, and immunotherapeutic management of HCC. Foxp3 + , CD8 + , CD3 + , and CD4 + T cells are the extensively researched subtypes of TILs. This article examines the functions and processes of several subtypes of TILs in HCC. Emerging T cell-based therapies, including TILs and chimeric antigen receptor (CAR)-T cell therapy, have shown tumor regression in several clinical and preclinical studies. Herein, it also delves into the existing T cell-based immunotherapies in HCC, with emphasis on TILs and CAR-T cells.

EGFR-Mutant Lung Adenocarcinoma Cell-Derived Exosomal miR-651-5p Induces CD8+ T Cell Apoptosis via Downregulating BCL2 Expression

Background: The efficacy of programmed cell death 1 (PD-1) or ligand 1 (PD-L1) inhibitors in epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer (NSCLC) patients is not satisfactory. Studies have indicated that the ratio of CD8+ tumor infiltration lymphocytes (TILs) was associated with immunotherapy efficacy; however, it was significantly lower in EGFR-mutant than wild type patients. The underlying mechanisms need to be studied. Methods: Database analysis, clinical specimens, small RNA sequencing, and single-cell sequencing were used to analyze miRNA expression and immune cell infiltration. Cell co-culture and flow cytometry were conducted to detect immune cell apoptosis. The mouse model was performed to analyze the influence of miR-651-5p antagomirs on the tumor microenvironment. Results: The miR-651-5p was found to be highly expressed in EGFR-mutant lung adenocarcinoma cell-derived exosomes, which could promote CD8+ T cell apoptosis, while the miR-651-5p inhibitor decreased the ratio of PC9-secreted exosomes and induced apoptosis. Mechanistically, the EGFR signaling pathway promoted the expression of miR-651-5p by activating the transcription factor Fos proto-oncogene (FOS) in EGFR-mutant lung adenocarcinoma cell lines. B-cell lymphoma 2 (BCL2) was the target of miR-651-5p, and miR-651-5p could promote T cell apoptosis by inhibiting BCL2 expression. In addition, the miR-651-5p antagomir increased T cell infiltration and enhanced the efficacy of the PD-1 inhibitor treating the EGFR-mutant lung adenocarcinoma humanized mouse model. Conclusions: EGFR-mutant lung adenocarcinoma promotes T cell apoptosis through exosomal miR-651-5p. miR-651-5p antagonists increase immune cell infiltration and enhance the anti-tumor effect of PD-1 inhibitor, suggesting a new combination therapy to improve the efficacy of immunotherapy in EGFR-mutant NSCLC patients.

The Novel Oncolytic Herpes Simplex Virus Type-1 (HSV-1) Vaccine Strain VC2 Constitutively Expressing GM-CSF Causes Increased Intratumoral T Cell Infiltration and Inhibition of Tumor Metastasis in the 4T1/Balb/c Mouse Model of Stage Four Breast Cancer

Oncolytic virotherapy (OVT) aims to disrupt the tumor microenvironment and provide a unique therapeutic approach against solid tumors. Herpes simplex virus type-1 (HSV-1) has shown strong promise for treating various solid tumors and has been approved to treat melanoma and glioma in human patients. Previously, we reported the generation of an engineered HSV-1 vaccine strain VC2, which has shown exceptional promise as an oncolytic and immunotherapeutic virus. In the present work, we engineered VC2 to constitutively express the murine granulocyte-macrophage colony-stimulating factor (GM-CSF) gene inserted in place of HSV-1 Glycoprotein C (gC). We tested the efficacy of VC2-GMCSF for its ability to generate antitumor response in the 4T1 stage four metastatic breast cancer mouse model. GM-CSF expression enhanced VC2 viral replication and infectious virus production. Tumors formed after 7 days of engraftment in the mammary fat pad of Balb/CJ mice were treated by injecting ~5 × 104 plaque forming units (PFU) of VC2/VC2-GMCSF once. Intratumor treatment did not appreciably reduce average primary tumor sizes. However, metastatic foci were significantly reduced in mice lungs treated with VC2-GMCSF compared to VC2 or mock treatment. VC2-GMCSF intratumoral treatment induced a stronger intratumor T cell infiltration but not an increased cytotoxic activity. A significant T cell infiltration was observed in the metastatic areas in VC2-GMCSF treated animals, which was associated with reduced pro-tumor marker PDL1 and VEGF gene expression. These results show that constitutive expression of GM-CSF enhanced the overall efficacy of VC2 for OVT. VC2-GMCSF holds promise as oncolytic and immunotherapeutic virotherapy for breast and other cancers.

Alternative splicing of modulatory immune receptors in T lymphocytes: a newly identified and targetable mechanism for anticancer immunotherapy

Alternative splicing (AS) is a mechanism that generates translational diversity within a genome. Equally important is the dynamic adaptability of the splicing machinery, which can give preference to one isoform over others encoded by a single gene. These isoform preferences change in response to the cell's state and function. Particularly significant is the impact of physiological alternative splicing in T lymphocytes, where specific isoforms can enhance or reduce the cells' reactivity to stimuli. This process makes splicing isoforms defining features of cell states, exemplified by CD45 splice isoforms, which characterize the transition from naïve to memory states. Two developments have accelerated the use of AS dynamics for therapeutic interventions: advancements in long-read RNA sequencing and progress in nucleic acid chemical modifications. Improved oligonucleotide stability has enabled their use in directing splicing to specific sites or modifying sequences to enhance or silence particular splicing events. This review highlights immune regulatory splicing patterns with potential significance for enhancing anticancer immunotherapy.

The Functional Role and Prognostic Significance of TIM-3 Expression on NK Cells in the Diagnostic Bone Marrows in Acute Myeloid Leukemia

Background: Compared to other immune checkpoint molecules, T cell immunoglobulin domain and mucin domain-3 (TIM-3) is highly expressed on natural killer (NK) cells, but its functional role and prognostic significance in acute myeloid leukemia (AML) remains unclear. This study aims to evaluate the role of TIM-3 expression on the cytotoxic and killing capacity of NK cells and its prognostic significance in AML. Methods: AML public single-cell RNA sequencing (scRNAseq) data were used to analyze the correlation of transcript levels between HAVCR2 (encoding TIM-3) and cytotoxic molecules in NK cells. NK cells from the bone marrows of seven newly diagnosed AML patients and five healthy donors (HDs) were stimulated in vitro and cell-killing activity was evaluated. A total of one hundred and five newly diagnosed adult AML patients and seven HDs were tested the expression of TIM-3 and cytotoxic molecules on the bone marrow NK cells by multi-parameter flow cytometry (MFC). Results: Both scRNAseq and MFC analysis demonstrated that TIM-3 expression on NK cells was positively related to the levels of perforin (PFP) and granzyme B (GZMB) (all p < 0.05) in AML. It was PFP and GZMB but not the TIM-3 level that was related to NK-cell-killing activity against K562 cells (p = 0.027, 0.042 and 0.55). A high frequency of TIM-3+ NK cells predicted poorer relapse-free survival (RFS) and event-free survival (EFS) (p = 0.013 and 0.0074), but was not an independent prognostic factor, whereas low GZMB levels in TIM-3+ NK cells independently predicted poorer RFS (p = 0.0032). Conclusions: TIM-3 expression on NK cells is positively related to PFP and GZMB levels but has no relation to cell-killing activity in AML, and low GZMB levels in TIM-3+ NK cells in the diagnostic bone marrows predicts poor outcomes. This study lays a theoretical foundation for the clinical application of immune checkpoint inhibitor treatment.

Ferroptosis exacerbates the clonal deletion of virus-specific exhausted CD8+ T cells

During chronic infection or tumorigenesis, persistent antigen stimulation contributes to the exhaustion of CD8+ T cells. Nevertheless, exhausted CD8+ T (TEX) cells still preserve certain effector function, and maintaining a reservoir of exhausted cells is of vital importance for virus elimination and tumor eradiation. Despite considerable work interrogating the rejuvenation of TEX cells, mechanisms underpinning the clonal deletion of TEX cells remain largely unexplored over the past decade. In this study, we employed mouse models of LCMV infection to demonstrate that excessive accumulation of lipid peroxidation rendered virus-specific TEX cells to ferroptosis, which may correlate with enhanced mitochondria-derived oxidative stress and compromised activity of glutathione peroxidase 4 (GPX4). In addition, either incomplete or complete ablation of GPX4 resulted in exacerbated ferroptosis and aggravated shrunken population of virus-specific TEX cells. On the other hand, inhibiting ferroptosis via administration of a ferroptosis inhibitor or overexpression of GPX4 greatly rectified the cell loss of virus-specific TEX cells. Collectively, we disclosed ferroptosis as a crucial player in the clonal deletion of virus-specific TEX cells and stressed the intervention of ferroptosis as a promising approach to optimize the longevity of virus-specific TEX cells.

Effect of Nicotinamide Riboside Against the Exhaustion of CD8+ T Cells via Alleviating Mitochondrial Dysfunction

Background: Targeting mitochondria and protecting the mitochondrial function of CD8+ T cells are crucial for enhancing the clinical efficacy of cancer immunotherapy. Objectives: In this study, our objective was to investigate the potential of nicotinamide riboside (NR) in preserving the mitochondrial function of CD8+ T cells and mitigating their exhaustion. Methods: We established two in vitro models to induce CD8+ T cell exhaustion either by tumor cell-conditioned medium (TCM) or by continuous stimulation with OVA(257-264) peptide. CD8+ T cells were treated in the absence/presence of NR. Results: Our findings demonstrated that NR supplementation effectively inhibited CD8+ T cell exhaustion and preserved mitochondrial function in both models. Moreover, apoptosis of CD8+ T cells was reduced after NR treatment. Western blot data indicated that NR treatment upregulated Silent information regulator 1 (SirT1) expression. Further inhibition of Sirt1 activity using EX527 uncovered that the inhibitory effect of NR on CD8+ T cell exhaustion and its protective effect on mitochondria were attenuated. Conclusions: In conclusion, our results indicate that NR supplementation attenuates CD8+ T cell exhaustion, and its underlying mechanism is associated with increased mitochondrial function regulated by the SirT1 pathway. Our research provides evidence that NR may assist in enhancing the clinical efficacy of immunotherapy.

The type 2 cytokine Fc-IL-4 revitalizes exhausted CD8+ T cells against cancer

Current cancer immunotherapy predominately focuses on eliciting type 1 immune responses fighting cancer; however, long-term complete remission remains uncommon1,2. A pivotal question arises as to whether type 2 immunity can be orchestrated alongside type 1-centric immunotherapy to achieve enduring response against cancer3,4. Here we show that an interleukin-4 fusion protein (Fc-IL-4), a typical type 2 cytokine, directly acts on CD8+ T cells and enriches functional terminally exhausted CD8+ T (CD8+ TTE) cells in the tumour. Consequently, Fc-IL-4 enhances antitumour efficacy of type 1 immunity-centric adoptive T cell transfer or immune checkpoint blockade therapies and induces durable remission across several syngeneic and xenograft tumour models. Mechanistically, we discovered that Fc-IL-4 signals through both signal transducer and activator of transcription 6 (STAT6) and mammalian target of rapamycin (mTOR) pathways, augmenting the glycolytic metabolism and the nicotinamide adenine dinucleotide (NAD) concentration of CD8+ TTE cells in a lactate dehydrogenase A-dependent manner. The metabolic modulation mediated by Fc-IL-4 is indispensable for reinvigorating intratumoural CD8+ TTE cells. These findings underscore Fc-IL-4 as a potent type 2 cytokine-based immunotherapy that synergizes effectively with type 1 immunity to elicit long-lasting responses against cancer. Our study not only sheds light on the synergy between these two types of immune responses, but also unveils an innovative strategy for advancing next-generation cancer immunotherapy by integrating type 2 immune factors.

PD-L2 drives resistance to EGFR-TKIs: dynamic changes of the tumor immune environment and targeted therapy

There is a lack of effective treatments to overcome resistance to EGFR-TKIs in EGFR mutant tumors. A deeper understanding of resistance mechanisms can provide insights into reducing or eliminating resistance, and can potentially deliver targeted treatment measures to overcome resistance. Here, we identified that the dynamic changes of the tumor immune environment were important extrinsic factors driving tumor resistance to EGFR-TKIs in EGFR mutant cell lines and syngeneic tumor-bearing mice. Our results demonstrate that the acquired resistance to EGFR-TKIs is accompanied by aberrant expression of PD-L2, leading a dynamic shift from an initially favorable tumor immune environment to an immunosuppressive phenotype. PD-L2 expression significantly affected EGFR mutant cell apoptosis that depended on the proportion and function of CD8+ T cells in the tumor immune environment. Combined with single-cell sequencing and experimental results, we demonstrated that PD-L2 specifically inhibited the proliferation of CD8+ T cells and the secretion of granzyme B and perforin, leading to reduced apoptosis mediated by CD8+ T cells and enhanced immune escape of tumor cells, which drives EGFR-TKIs resistance. Importantly, we have identified a potent natural small-molecule inhibitor of PD-L2, zinc undecylenate. In vitro, it selectively and potently blocks the PD-L2/PD-1 interaction. In vivo, it abolishes the suppressive effect of the PD-L2-overexpressing tumor immune microenvironment by blocking PD-L2/PD-1 signaling. Moreover, the combination of zinc undecylenate and EGFR-TKIs can synergistically reverse tumor resistance, which is dependent on CD8+ T cells mediating apoptosis. Our study uncovers the PD-L2/PD-1 signaling pathway as a driving factor to mediate EGFR-TKIs resistance, and identifies a new naturally-derived agent to reverse EGFR-TKIs resistance.

Osr2 functions as a biomechanical checkpoint to aggravate CD8+ T cell exhaustion in tumor

Alterations in extracellular matrix (ECM) architecture and stiffness represent hallmarks of cancer. Whether the biomechanical property of ECM impacts the functionality of tumor-reactive CD8+ T cells remains largely unknown. Here, we reveal that the transcription factor (TF) Osr2 integrates biomechanical signaling and facilitates the terminal exhaustion of tumor-reactive CD8+ T cells. Osr2 expression is selectively induced in the terminally exhausted tumor-specific CD8+ T cell subset by coupled T cell receptor (TCR) signaling and biomechanical stress mediated by the Piezo1/calcium/CREB axis. Consistently, depletion of Osr2 alleviates the exhaustion of tumor-specific CD8+ T cells or CAR-T cells, whereas forced Osr2 expression aggravates their exhaustion in solid tumor models. Mechanistically, Osr2 recruits HDAC3 to rewire the epigenetic program for suppressing cytotoxic gene expression and promoting CD8+ T cell exhaustion. Thus, our results unravel Osr2 functions as a biomechanical checkpoint to exacerbate CD8+ T cell exhaustion and could be targeted to potentiate cancer immunotherapy.

Batf3+ DCs and the 4-1BB/4-1BBL axis are required at the effector phase in the tumor microenvironment for PD-1/PD-L1 blockade efficacy

The cellular source of positive signals that reinvigorate T cells within the tumor microenvironment (TME) for the therapeutic efficacy of programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) blockade has not been clearly defined. We now show that Batf3-lineage dendritic cells (DCs) are essential in this process. Flow cytometric analysis, gene-targeted mice, and blocking antibody studies revealed that 4-1BBL is a major positive co-stimulatory signal provided by these DCs within the TME that translates to CD8+ T cell functional reinvigoration and tumor regression. Immunofluorescence and spatial transcriptomics on human tumor samples revealed clustering of Batf3+ DCs and CD8+ T cells, which correlates with anti-PD-1 efficacy. In addition, proximity to Batf3+ DCs within the TME is associated with CD8+ T cell transcriptional states linked to anti-PD-1 response. Our results demonstrate that Batf3+ DCs within the TME are critical for PD-1/PD-L1 blockade efficacy and indicate a major role for the 4-1BB/4-1BB ligand (4-1BBL) axis during this process.

Apoptosis, a Metabolic "Head-to-Head" between Tumor and T Cells: Implications for Immunotherapy

Induction of apoptosis represents a promising therapeutic approach to drive tumor cells to death. However, this poses challenges due to the intricate nature of cancer biology and the mechanisms employed by cancer cells to survive and escape immune surveillance. Furthermore, molecules released from apoptotic cells and phagocytes in the tumor microenvironment (TME) can facilitate cancer progression and immune evasion. Apoptosis is also a pivotal mechanism in modulating the strength and duration of anti-tumor T-cell responses. Combined strategies including molecular targeting of apoptosis, promoting immunogenic cell death, modulating immunosuppressive cells, and affecting energy pathways can potentially overcome resistance and enhance therapeutic outcomes. Thus, an effective approach for targeting apoptosis within the TME should delicately balance the selective induction of apoptosis in tumor cells, while safeguarding survival, metabolic changes, and functionality of T cells targeting crucial molecular pathways involved in T-cell apoptosis regulation. Enhancing the persistence and effectiveness of T cells may bolster a more resilient and enduring anti-tumor immune response, ultimately advancing therapeutic outcomes in cancer treatment. This review delves into the pivotal topics of this multifaceted issue and suggests drugs and druggable targets for possible combined therapies.

Increased co-expression of 4-1BB with PD-1 on CD8+ tumor-infiltrating lymphocytes is associated with improved prognosis and immunotherapy response in cervical cancer

Background

The combination of agonistic antibodies with immune checkpoint inhibitors presents a promising avenue for cancer immunotherapy. Our objective is to explore the co-expression of 4-1BB, ICOS, CD28, with PD-1 on CD8+ T cells in the peripheral blood and tumor tissue of cervical cancer(CC) patients, with a specific focus on the association between the co-expression levels of 4-1BB with PD-1 and clinical features, prognosis as well as immunotherapy response. The goal is to offer valuable insights into cervical cancer immunotherapy.

Methods

In this study, 50 treatment-naive patients diagnosed with CC were enrolled. Flow cytometry was used to detect PD-1/4-1BB, PD-1/ICOS and PD-1/CD28 co-expression on CD8+ T cells. Subsequent analysis aimed to investigate the differential co-expression between peripheral blood and cancer tissue, and also the correlation between co-expression and clinical features in these patients. Gene Expression Omnibus (GEO) datasets, The Cancer Genome Atlas (TCGA) cohort, The IMvigor210 cohort, The BMS038cohort and Immunophenoscores were utilized to investigate the correlation between PD-1/4-1BB and the immune microenvironment, prognosis, immunotherapy, and drug sensitivity in cervical cancer.

Results

The co-expression levels of PD-1/4-1BB, PD-1/ICOS, and PD-1/CD28 on CD8+ tumor-infiltrating lymphocytes (TILs) were significantly higher in cervical cancer patients compared to those in peripheral blood. Clinical feature analysis reveals that on CD8+ TILs, the co-expression of PD-1/4-1BB is more closely correlated with clinical characteristics compared to PD-1/ICOS, PD-1/CD28, PD-1, and 4-1BB. Pseudo-time analysis and cell communication profiling reveal close associations between the subgroups harboring 4-1BB and PD-1. The prognosis, tumor mutation burden, immune landscape, and immunotherapy response exhibit statistically significant variations between the high and low co-expression groups of PD-1/4-1BB. The high co-expression group of PD-1/4-1BB is more likely to benefit from immunotherapy.

Conclusion

PD-1/4-1BB, PD-1/ICOS, and PD-1/CD28 exhibit elevated co-expression on CD8+TILs of cervical cancer, while demonstrating lower expression in circulating T cells. The co-expression patterns of PD-1/4-1BB significantly contributed to the prediction of immune cell infiltration characteristics, prognosis, and tailored immunotherapy tactics. PD-1/4-1BB exhibits potential as a target for combination immunotherapy in cervical cancer.

Development of a First-in-Class RIPK1 Degrader to Enhance Antitumor Immunity

The scaffolding function of receptor interacting protein kinase 1 (RIPK1) confers intrinsic and extrinsic resistance to immune checkpoint blockades (ICBs) and has emerged as a promising target for improving cancer immunotherapies. To address the challenge posed by a poorly defined binding pocket within the intermediate domain, we harnessed proteolysis targeting chimera (PROTAC) technology to develop a first-in-class RIPK1 degrader, LD4172. LD4172 exhibited potent and selective RIPK1 degradation both in vitro and in vivo. Degradation of RIPK1 by LD4172 triggered immunogenic cell death (ICD) and enriched tumor-infiltrating lymphocytes and substantially sensitized the tumors to anti-PD1 therapy. This work reports the first RIPK1 degrader that serves as a chemical probe for investigating the scaffolding functions of RIPK1 and as a potential therapeutic agent to enhance tumor responses to immune checkpoint blockade therapy.

Targeting Wnt signaling for improved glioma immunotherapy

Introduction

Despite aggressive standard-of-care therapy, including surgery, radiation, and chemotherapy, glioblastoma recurrence is almost inevitable and uniformly lethal. Activation of glioma-intrinsic Wnt/β-catenin signaling is associated with a poor prognosis and the proliferation of glioma stem-like cells, leading to malignant transformation and tumor progression. Impressive results in a subset of cancers have been obtained using immunotherapies including anti-CTLA4, anti-PD-1, and anti-PD-L1 or chimeric antigen receptor (CAR) T cell therapies. However, the heterogeneity of tumors, low mutational burden, single antigen targeting, and associated antigen escape contribute to non-responsiveness and potential tumor recurrence despite these therapeutic efforts. In the current study, we determined the effects of the small molecule, highly specific Wnt/CBP (CREB Binding Protein)/β-catenin antagonist ICG-001, on glioma tumor cells and the tumor microenvironment (TME)-including its effect on immune cell infiltration, blood vessel decompression, and metabolic changes.

Methods

Using multiple glioma patient-derived xenografts cell lines and murine tumors (GL261, K-Luc), we demonstrated in vitro cytostatic effects and a switch from proliferation to differentiation after treatment with ICG-001.

Results

In these glioma cell lines, we further demonstrated that ICG-001 downregulated the CBP/β-catenin target gene Survivin/BIRC5-a hallmark of Wnt/CBP/β-catenin inhibition. We found that in a syngeneic mouse model of glioma (K-luc), ICG-001 treatment enhanced tumor infiltration by CD3+ and CD8+ cells with increased expression of the vascular endothelial marker CD31 (PECAM-1). We also observed differential gene expression and induced immune cell infiltration in tumors pretreated with ICG-001 and then treated with CAR T cells as compared with single treatment groups or when ICG-001 treatment was administered after CAR T cell therapy.

Discussion

We conclude that specific Wnt/CBP/β-catenin antagonism results in pleotropic changes in the glioma TME, including glioma stem cell differentiation, modulation of the stroma, and immune cell activation and recruitment, thereby suggesting a possible role for enhancing immunotherapy in glioma patients.

Role of myeloid-derived suppressor cells in chronic brucellosis

Introduction

Human brucellosis, a Brucella infection caused most common zoonosis in the world, remains a serious public health burden in China. Brucella chronic infection always causes immunosuppressive status and results in severe organ or tissue damages. The aim of this work was to study the role of the myeloid-derived suppressor cells (MDSCs) in human chronic brucellosis.

Methods

Fifty cases of chronic brucellosis and 40 healthy individual controls were enrolled in this study. We analyzed the frequency and subsets of MDSCs in PBMC between the chronic brucellosis and healthy control groups by flow cytometry. Furthermore, we also measured the inflammatory-related cytokines in serum samples and the MDSCs inhibition ability to the proliferation of T cells in vitro.

Results

We found that the frequency of MDSCs in peripheral blood and the level of IL-6 and IL-10 Th2 cytokines and Arginase-1 were significantly increased in chronic brucellosis patients. In addition, we also found that the T cell function was suppressed in vitro by co-culturing with MDSCs from brucellosis patients.

Conclusion

Our study described an increase of immunosuppressive MDSCs in peripheral blood of chronic brucellosis patients. These results contribute to the understanding of Brucella persistent infection, which may provide an insight for effective treatment of chronic brucellosis patients in clinical practice.

CD36: The Bridge between Lipids and Tumors

It has been found that the development of some cancers can be attributed to obesity, which is associated with the excessive intake of lipids. Cancer cells undergo metabolic reprogramming, shifting from utilizing glucose to fatty acids (FAs) for energy. CD36, a lipid transporter, is highly expressed in certain kinds of cancer cells. High expressions of CD36 in tumor cells triggers FA uptake and lipid accumulation, promoting rapid tumor growth and initiating metastasis. Meanwhile, immune cells in the tumor microenvironment overexpress CD36 and undergo metabolic reprogramming. CD36-mediated FA uptake leads to lipid accumulation and has immunosuppressive effects. This paper reviews the types of FAs associated with cancer, high expressions of CD36 that promote cancer development and progression, effects of CD36 on different immune cells in the tumor microenvironment, and the current status of CD36 as a therapeutic target for the treatment of tumors with high CD36 expression.

Tespa1 deficiency reduces the antitumour immune response by decreasing CD8+T cell activity in a mouse Lewis lung cancer model

Thymocyte-expressed, positive selection-associated 1 (Tespa1) is a key molecule in T-cell development and has been linked to immune diseases. However, its role in antitumour CD8+T cell immunity remains unclear. Here, we demonstrated that Tespa1 plays an important role in antitumour CD8+T cell immunity. First, compared with wild-type (WT) mice, Lewis lung cancer cells grew faster in Tespa1 knockout (Tespa1-/-) mice, with reduced apoptosis, and decreased CD8+T cells in peripheral blood and tumor tissues. Second, the proportion of CD8+T and Th1 cells in the splenocytes of Tespa1-/- mice was lower than that in WT mice. Third, Tespa1-/- CD8+ tumor-infiltrating lymphocytes (TILs) showed weakened proliferation, invasion, cytotoxicity, and protein expression of IL-2 signalling pathway components compared to WT CD8+TILs. Furthermore, PD-1 expression in CD8+TILs was higher in Tespa1-/- than in WT mice. Lastly, CD8+TILs in WT mice improved the antitumour ability of Tespa1-/- mice. In conclusion, these findings suggest that Tespa1 plays a critical role in the tumor immune system by regulating CD8+T cells.

SLC10A3 Is a Prognostic Biomarker and Involved in Immune Infiltration and Programmed Cell Death in Lower Grade Glioma

BACKGROUND

The association between SLC10A3 (solute carrier family 10 member 3) and lower grade glioma (LGG) remains unclear.

METHODS

We used public databases and bioinformatics analysis to analyze SLC10A3. These included The Cancer Genome Atlas, Genotype-Tissue Expansion, Chinese Glioma Genome Atlas, Human Protein Atlas, GeneCards, cBioPortal, Search Tool for the Retrieval of Interacting Genes/Proteins, Gene Expression Profiling Interactive Analysis, Tumor Immune Estimation Resource, Tumor-Immune System Interaction Database, receiver operating characteristic curve analysis, Kaplan-Meier analysis, Cox analysis, nomograms, calibration plots, gene ontology/Kyoto Encyclopedia of Genes and Genomes enrichment analysis, gene set enrichment analysis, single-sample gene set enrichment analysis, and Spearman's correlation analysis.

RESULTS

SLC10A3 was upregulated in adrenocortical carcinoma, glioblastoma, and LGG and was associated with good overall survival (OS) in adrenocortical carcinoma and poor OS in LGG and glioblastoma. SLC10A3 was increased with increased World Health Organization grade, upregulated in isocitrate dehydrogenase-wild type, 1p/19q (chromosome arms 1p and 19q) non-co-deleted, and higher in astrocytoma. Patients with LGG were grouped by the occurrence of the clinical outcome endpoints (i.e., OS, disease-specific survival [DSS], and progression-free interval events). Genetic alterations in SLC10A3 were associated with poor progression-free survival in LGG. Most of clinical characteristics were associated with the SLC10A3 expression level. SLC10A3 with diagnostic and prognostic value (OS, DSS, and progression-free interval) was an independent prognostic factor in LGG. Moreover, Nomograms (WHO grade, 1p/19q codeletion, age and SLC10A3) had moderately accurate predictive for OS and DSS. Functional analysis showed that SLC10A3 might participate in the transport of multiple substances, neurogenic signaling, immune response, and programmed cell death in LGG. SLC10A3 correlated with immune infiltration in LGG and moderately correlated with the gene signature of pyroptosis, lysosome-dependent cell death, necroptosis, apoptosis, ferroptosis, alkaliptosis, and autophagy-dependent cell death.

CONCLUSIONS

SLC10A3 is a potential diagnostic and prognostic biomarker for LGG and might be associated with substance transport, neurogenic signaling, immune infiltration, and programmed cell death in LGG.

Multiplatform Analysis of Intratumoral PTEN Heterogeneity in Melanoma

Loss of protein expression of the tumor suppressor PTEN is associated with increased cancer aggressiveness, decreased tumor immune infiltration, and resistance to immune and targeted therapies in melanoma. We assessed a unique cohort of eight melanoma samples with focal loss of PTEN protein expression to understand the features and mechanisms of PTEN loss in this disease. We compared the PTEN-negative (PTEN[-]) areas to their adjacent PTEN-positive (PTEN[+]) areas using DNA sequencing, DNA methylation, RNA expression, digital spatial profiling, and immunohistochemical platforms. Variations or homozygous deletions of PTEN were identified in PTEN(-) areas that were not detected in the adjacent PTEN(+) areas in three cases (37.5%), but no clear genomic or DNA methylation basis for loss was identified in the remaining PTEN(-) samples. RNA expression data from two independent platforms identified a consistent increase in chromosome segregation gene expression in PTEN(-) versus adjacent PTEN(+) areas. Proteomic analysis showed a relative paucity of tumor-infiltrating lymphocytes in PTEN(-) versus adjacent PTEN(+) areas. The findings add to our understanding of potential molecular intratumoral heterogeneity in melanoma and the features associated with the loss of PTEN protein in this disease.

The regulation of PTEN: Novel insights into functions as cancer biomarkers and therapeutic targets

This review summarizes the implications of the primary tumor suppressor protein phosphatase and tensin homolog (PTEN) in aggressive cancer development. PTEN interacts with other cellular proteins or factors suggesting the existence of an intricate molecular network that regulates their oncogenic function. Accumulating evidence has shown that PTEN exists and plays a role in the cytoplasmic organelles and in the nucleus. PTEN blocks phosphoinositide 3-kinases (PI3K)-protein kinase B-mammalian target of rapamycin signaling pathway by dephosphorylating phosphatidylinositol (PI)-3,4,5-triphosphate to PI-4,5-bisphosphate thus counteracting PI3K function. Studies have shown that PTEN expression is tightly regulated at transcriptional, posttranscriptional, and posttranslational levels (including protein-protein interactions and posttranslational modifications). Despite recent advances in PTEN research, the regulation and function of the PTEN gene remain largely unknown. How mutation or loss of specific exons in the PTEN gene occurs and involves in cancer development is not clear. This review illustrates the regulatory mechanisms of PTEN expression and discusses how PTEN participates in tumor development and/or suppression. Future prospects for the clinical applications are also highlighted.

Salidroside suppresses the multiple oncogenic activates and immune escape of lung adenocarcinoma through the circ_0009624-mediated PD-L1 pathway

BACKGROUND

Lung adenocarcinoma (LUAD) is a fatal malignancy all over the world. Salidroside (SAL) is an active component extracted from Rhodiola rosea that has been reported to exert antitumor activity against several human cancers, containing lung adenocarcinoma (LUAD). The purpose of this study was to explore the effect and underlying mechanism of SAL in LUAD.

METHODS

Cell viability, proliferation, migration, and invasion were measured using cell counting kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), and transwell assays. Effects of LUAD cells on the cytotoxicity, percentage, and death of CD8+ cells were detected using lactate dehydrogenase (LDH) and flow cytometry assays. Programmed cell death ligand 1 (PD-L1) protein level was examined using western blot. Circ_0009624, enolase 1 (ENO1), and PD-L1 levels were determined using real-time quantitative polymerase chain reaction (RT-qPCR). The biological role of SAL on LUAD tumor growth was assessed using the xenograft tumor model in vivo.

RESULTS

SAL restrained LUAD cell proliferation, migration, invasion, and immune escape in vitro via modulating PD-L1. Circ_0009624 expression was increased in LUAD. Applying SAL repressed circ_0009624 and PD-L1 expression in LUAD cells. SAL treatment hindered suppressed various oncogenic activates and immune escape of LUAD cells by regulating the circ_0009624/PD-L1 pathway. SAL blocked LUAD xenograft growth in vivo.

CONCLUSION

Applying SAL might constrain malignant phenotypes and immune escape of LUAD cells partially through the circ_0009624-mediated PD-L1 pathway, providing a novel insight for LUAD treatment.

Lima JC, Langohr IM, Chouljenko VN, Kousoulas KG. The Oncolytic herpes simplex virus type-1 (HSV-1) vaccine strain VC2 causes intratumor infiltration of functionally active T cells and inhibition of tumor metastasis and pro-tumor genes VEGF and PDL1 expression in the 4T1/Balb/c mouse model of stage four breast cancer

Introduction: Oncolytic viruses (OVs) provide new modalities for cancer therapy either alone or in combination with synergistic immunotherapies and/or chemotherapeutics. Engineered Herpes Simplex Virus Type-1 (HSV-1) has shown strong promise for the treatment of various cancers in experimental animal models as well as in human patients, with some virus strains licensed to treat human melanoma and gliomas. In the present study we evaluated the efficacy of mutant HSV-1 (VC2) in a late stage, highly metastatic 4T1 murine syngeneic. Method: VC2 was constructed VC2 using double red recombination technology. For in-vivo efficacy we utilized a late stage 4T1 syngeneic and immunocompetent BALB/cJ mouse model breast cancer model which exhibits efficient metastasis to the lung and other organs. Results: VC2 replicated efficiently in 4T1 cells and in cell culture, achieving titers similar to those in African monkey kidney (Vero) cells. Intra-tumor treatment with VC2 did not appreciably reduce average primary tumor sizes but a significant reduction of lung metastasis was noted in mice treated intratumorally with VC2, but not with ultraviolet-inactivated VC2. This reduction of metastasis was associated with increased T cell infiltration comprised of CD4+ and CD4+CD8+ double-positive T cells. Characterization of purified tumor infiltrating T cells revealed a significant improvement in their proliferation ability compared to controls. In addition, significant T cell infiltration was observed in the metastatic nodules associated with reduction of pro-tumor PD-L1 and VEGF gene transcription. Conclusion: These results show that VC2 therapy can improve anti-tumor response associated with a better control of tumor metastasis. improve T cell responses and reduce pro-tumor biomarker gene transcription. VC2 holds promise for further development as an oncolytic and immunotherapeutic approach to treat breast and other cancers.

Novel Fas-TNFR chimeras that prevent Fas ligand-mediated kill and signal synergistically to enhance CAR T cell efficacy

The hostile tumor microenvironment limits the efficacy of adoptive cell therapies. Activation of the Fas death receptor initiates apoptosis and disrupting these receptors could be key to increasing CAR T cell efficacy. We screened a library of Fas-TNFR proteins identifying several novel chimeras that not only prevented Fas ligand-mediated kill, but also enhanced CAR T cell efficacy by signaling synergistically with the CAR. Upon binding Fas ligand, Fas-CD40 activated the NF-κB pathway, inducing greatest proliferation and IFN-γ release out of all Fas-TNFRs tested. Fas-CD40 induced profound transcriptional modifications, particularly genes relating to the cell cycle, metabolism, and chemokine signaling. Co-expression of Fas-CD40 with either 4-1BB- or CD28-containing CARs increased in vitro efficacy by augmenting CAR T cell proliferation and cancer target cytotoxicity, and enhanced tumor killing and overall mouse survival in vivo. Functional activity of the Fas-TNFRs were dependent on the co-stimulatory domain within the CAR, highlighting crosstalk between signaling pathways. Furthermore, we show that a major source for Fas-TNFR activation derives from CAR T cells themselves via activation-induced Fas ligand upregulation, highlighting a universal role of Fas-TNFRs in augmenting CAR T cell responses. We have identified Fas-CD40 as the optimal chimera for overcoming Fas ligand-mediated kill and enhancing CAR T cell efficacy.

Leveraging immune resistance archetypes in solid cancer to inform next-generation anticancer therapies

Anticancer immunotherapies, such as immune checkpoint inhibitors, bispecific antibodies, and chimeric antigen receptor T cells, have improved outcomes for patients with a variety of malignancies. However, most patients either do not initially respond or do not exhibit durable responses due to primary or adaptive/acquired immune resistance mechanisms of the tumor microenvironment. These suppressive programs are myriad, different between patients with ostensibly the same cancer type, and can harness multiple cell types to reinforce their stability. Consequently, the overall benefit of monotherapies remains limited. Cutting-edge technologies now allow for extensive tumor profiling, which can be used to define tumor cell intrinsic and extrinsic pathways of primary and/or acquired immune resistance, herein referred to as features or feature sets of immune resistance to current therapies. We propose that cancers can be characterized by immune resistance archetypes, comprised of five feature sets encompassing known immune resistance mechanisms. Archetypes of resistance may inform new therapeutic strategies that concurrently address multiple cell axes and/or suppressive mechanisms, and clinicians may consequently be able to prioritize targeted therapy combinations for individual patients to improve overall efficacy and outcomes.

A Pan-Cancer Analysis of Prognostic and Immunological Roles for Cell Death Genes

The dysregulation of cell death is closely associated with the development, progression, tumor microenvironment (TME), and prognosis of cancer. However, there is no study that comprehensively explores the prognostic and immunological role of cell death in human pan-cancer. We used published human pan-cancer RNA-sequencing and clinical data to explore the prognostic and immunological roles of programmed cell death, which included apoptosis, autophagy, ferroptosis, necroptosis, and pyroptosis. A total of 9925 patients were included for bioinformatic analysis, with 6949 and 2976 patients in the training cohort and validation cohort, respectively. Five-hundred and ninety-nine genes were defined as programmed-cell-death-related genes. In the training cohort, 75 genes were identified to define PAGscore by survival analysis. According to the median value of PAGscore, patients were divided into high- and low-risk groups, and subsequent analyses demonstrated that the high-risk group had a higher level of genomic mutation frequency, hypoxia score, immuneScore, expression of immune genes, activity of malignant signaling pathways, and cancer immunity cycle. Most anti-tumor and pro-tumor components of the TME showed greater activity in high-risk patients. Scores of malignant cell properties were also higher in high-risk patients. These findings were confirmed in the validation cohort and external cohort. Our study constructed a reliable gene signature to distinguish prognosis-favorable and prognosis-unfavorable patients and demonstrated that cell death was significantly associated with cancer prognosis and the TME.

Autoimmunity and Carcinogenesis: Their Relationship under the Umbrella of Autophagy

The immune system and autophagy share a functional relationship. Both innate and adaptive immune responses involve autophagy and, depending on the disease's origin and pathophysiology, it may have a detrimental or positive role on autoimmune disorders. As a "double-edged sword" in tumors, autophagy can either facilitate or impede tumor growth. The autophagy regulatory network that influences tumor progression and treatment resistance is dependent on cell and tissue types and tumor stages. The connection between autoimmunity and carcinogenesis has not been sufficiently explored in past studies. As a crucial mechanism between the two phenomena, autophagy may play a substantial role, though the specifics remain unclear. Several autophagy modifiers have demonstrated beneficial effects in models of autoimmune disease, emphasizing their therapeutic potential as treatments for autoimmune disorders. The function of autophagy in the tumor microenvironment and immune cells is the subject of intensive study. The objective of this review is to investigate the role of autophagy in the simultaneous genesis of autoimmunity and malignancy, shedding light on both sides of the issue. We believe our work will assist in the organization of current understanding in the field and promote additional research on this urgent and crucial topic.

TGF-β2 antisense oligonucleotide enhances T-cell mediated anti-tumor activities by IL-2 via attenuation of fibrotic reaction in a humanized mouse model of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancers, with high mortality and recurrence rate. In this study, we generated a human immune system mouse model by transplanting human peripheral blood mononuclear cells into NSG-B2m mice followed by xenografting AsPC-1 cells, after which we assessed the role of transforming growth factor-β2 (TGF-β2) in T-cell-mediated anti-tumor immunity. We observed that inhibiting the TGF-β2 production by TGF-β2 antisense oligonucleotide (TASO) combined with IL-2 delays pancreatic cancer growth. Co-treatment of TASO and IL-2 had little effect on the SMAD-dependent pathway, but significantly inhibited the Akt phosphorylation and sequentially activated GSK-3β. Activation of GSK-3β by TASO subsequently suppressed β-catenin and α-SMA expression and resulted in attenuated fibrotic reactions, facilitating the infiltration of CD8 + cytotoxic T lymphocytes (CTLs) into the tumor. TGF-β2 inhibition suppressed the Foxp3 + regulatory T-cells in peripheral blood and tumors, thereby enhancing the tumoricidal effects of CTLs associated with increased granzyme B and cleaved caspase-3. Moreover, changes in the T-cell composition in peripheral blood and at the tumor site by TASO and IL-2 induced the increase of pro-inflammatory cytokines such as IFN-γ and TNF-α and the decrease of anti-inflammatory cytokines such as TGF-βs. These results indicate that the TGF-β2 inhibition by TASO combined with IL-2 enhances the T-cell mediated anti-tumor immunity against SMAD4-mutated PDAC by modulating the tumor-associated fibrosis, suggesting that TASO in combination with IL-2 may be a promising immunotherapeutic intervention for PDAC.

Enforced expression of Runx3 improved CAR-T cell potency in solid tumor via enhancing resistance to activation-induced cell death

Limited T cell persistence restrains chimeric antigen receptor (CAR)-T cell therapy in solid tumors. To improve persistence, T cells have been engineered to secrete proinflammatory cytokines, but other possible methods have been understudied. Runx3 has been considered a master regulator of T cell development, cytotoxic T lymphocyte differentiation, and tissue-resident memory T (Trm)-cell formation. A study using a transgenic mouse model revealed that overexpression of Runx3 promoted T cell persistence in solid tumors. Here, we generated CAR-T cells overexpressing Runx3 (Run-CAR-T cells) and found that Run-CAR-T cells had long-lasting antitumor activities and achieved better tumor control than conventional CAR-T cells. We observed that more Run-CAR-T cells circulated in the peripheral blood and accumulated in tumor tissue, indicating that Runx3 coexpression improved CAR-T cell persistence in vivo. Tumor-infiltrating Run-CAR-T cells showed less cell death with enhanced proliferative and effector activities. Consistently, in vitro studies indicated that AICD was also decreased in Run-CAR-T cells via downregulation of tumor necrosis factor (TNF) secretion. Further studies revealed that Runx3 could bind to the TNF promoter and suppress its gene transcription after T cell activation. In conclusion, Runx3-armored CAR-T cells showed increased antitumor activities and could be a new modality for the treatment of solid tumors.

A dhesion analysis via a tumor vasculature-like microfluidic device identifies CD8+ T cells with enhanced tumor homing to improve cell therapy

CD8⁺ T cell recruitment to the tumor microenvironment is critical for the success of adoptive cell therapy (ACT). Unfortunately, only a small fraction of transferred cells home to solid tumors. Adhesive ligand-receptor interactions have been implicated in CD8⁺ T cell homing; however, there is a lack of understanding of how CD8⁺ T cells interact with tumor vasculature-expressed adhesive ligands under the influence of hemodynamic flow. Here, the capacity of CD8⁺ T cells to home to melanomas is modeled ex vivo using an engineered microfluidic device that recapitulates the hemodynamic microenvironment of the tumor vasculature. Adoptively transferred CD8⁺ T cells with enhanced adhesion in flow in vitro and tumor homing in vivo improve tumor control by ACT in combination with immune checkpoint blockade. These results show that engineered microfluidic devices can model the microenvironment of the tumor vasculature to identify subsets of T cells with enhanced tumor infiltrating capabilities, a key limitation in ACT.

Highly expressed CENPL is correlated with breast cancer cell proliferation and immune infiltration

Background

Centromere protein L (CENPL) is associated with a variety of human diseases. However, its function in breast cancer remains uncertain.

Methods

The Cancer Genome Atlas (TCGA) and genotype-tissue expression across cancer data were used to investigate CENPL expression. Using TCGA clinical survival data, the relationship between CENPL expression and patient prognosis was assessed. Using the cluster profiler R software tool, enrichment analysis of CENPL was carried out. Additionally, by studying the TCGA database, the relationship between CENPL expression and immune cell infiltration was assessed. To evaluate CENPL's impact on breast cancer cell proliferation, the CCK8 test and colony-formation assay were carried out. Scratch testing and the transwell assay were used to evaluate the effects of CENPL on breast cancer cell migration.

Results

Breast cancer was one of numerous tumor forms with high CENPL expression. Significant relationships between high CENPL expression and the cell cycle, nuclear division, organelle fission, and chromosome segregation were found. Further investigation revealed that minimal infiltration of CD8-positive T cells and natural killer (NK) cells and high levels of Tregs and macrophages were correlated with high levels of CENPL expression. CENPL expression was linked to more than half of the ICP genes. Breast cancer cells' ability to proliferate and migrate was decreased by CENPL knockdown.

Conclusions

Our findings suggest that CENPL may be an oncogene in breast cancer and a predictor of efficacy of immunotherapy for breast cancer.

Hypoxia drives CD39-dependent suppressor function in exhausted T cells to limit antitumor immunity

CD8+ T cells are critical for elimination of cancer cells. Factors within the tumor microenvironment (TME) can drive these cells to a hypofunctional state known as exhaustion. The most terminally exhausted T (tTex) cells are resistant to checkpoint blockade immunotherapy and might instead limit immunotherapeutic efficacy. Here we show that intratumoral CD8+ tTex cells possess transcriptional features of CD4+Foxp3+ regulatory T cells and are similarly capable of directly suppressing T cell proliferation ex vivo. tTex cell suppression requires CD39, which generates immunosuppressive adenosine. Restricted deletion of CD39 in endogenous CD8+ T cells resulted in slowed tumor progression, improved immunotherapy responsiveness and enhanced infiltration of transferred tumor-specific T cells. CD39 is induced on tTex cells by tumor hypoxia, thus mitigation of hypoxia limits tTex suppression. Together, these data suggest tTex cells are an important regulatory population in cancer and strategies to limit their generation, reprogram their immunosuppressive state or remove them from the TME might potentiate immunotherapy.

[Advances of Immunotherapy Resistance and Coping Strategies in Non-small Cell Lung Cancer]

Immunotherapy has significantly improved clinical outcomes of non-small cell lung cancer (NSCLC), however, along with the popularization of immunotherapy, immune resistance has become an unavoidable problem. Immunotherapy can induce extensive cellular and molecular alterations in the tumor microenvironment. Considering the mechanisms of immune resistance are not yet fully understood and the efficacy of standard chemotherapy regimens is limited, more effective coping strategies based on resistance mechanisms are urgently needed. In this review, we intend to summarize the known mechanisms of immune resistance and feasible strategies, so as to provide a foundation for clinicians to develop more individualized and precise regimens and finally improve patients' prognosis.
.

Pre-treatment systemic immune-inflammation index as a non-invasive biomarker for predicting clinical outcomes in patients with renal cell carcinoma: a meta-analysis of 20 studies

INTRODUCTION

To systematically assess the predictive significance of systemic immune-inflammation index (SII) in renal cell carcinoma (RCC).

METHODS

Relevant studies published before November 2022 were retrieved from public databases. Hazard ratio (HR), standardised mean difference (SMD) and relative risk (RR) were calculated to estimate associations of SII with prognosis, treatment responses and clinicopathological features.

RESULTS

Twenty studies involving 6887 patients were eligible. The meta-analysis results revealed a high SII level was associated with worse overall survival (HR: 1.45, p < 0.001), progression-free survival (HR: 1.63, p = 0.001), cancer-specific survival (HR: 1.86, p < 0.001), lower overall response rate (RR: 0.62, p = 0.003), disease control rate (RR: 0.69, p = 0.002), larger tumour size (SMD: 0.39, p = 0.001), poorer IMDC risk (RR: 7.09, p < 0.001), higher Fuhrman grade (RR: 1.54, p = 0.004), tumour stage (RR: 1.67, p = 0.045), the presence of distant metastasis (brain: RR, 2.04, p = 0.001; bone: RR, 1.33, p = 0.024) and tumour necrosis (RR: 1.57, p = 0.031). Subgroup analysis showed SII predicted OS and PFS for non-Asian, but CSS for both Asian and non-Asian populations.

CONCLUSION

Pre-treatment SII may be a promising predictor of clinical outcomes for RCC patients.

FOXP3 expression diversifies the metabolic capacity and enhances the efficacy of CD8 T cells in adoptive immunotherapy of melanoma

Regulatory T cells overwhelm conventional T cells in the tumor microenvironment (TME) thanks to a FOXP3-driven metabolic program that allows them to engage different metabolic pathways. Using a melanoma model of adoptive T cell therapy (ACT), we show that FOXP3 overexpression in mature CD8 T cells improved their antitumor efficacy, favoring their tumor recruitment, proliferation, and cytotoxicity. FOXP3-overexpressing (Foxp3UP) CD8 T cells exhibited features of tissue-resident memory-like and effector T cells, but not suppressor activity. Transcriptomic analysis of tumor-infiltrating Foxp3UP CD8 T cells showed positive enrichment in a wide variety of metabolic pathways, such as glycolysis, fatty acid (FA) metabolism, and oxidative phosphorylation (OXPHOS). Intratumoral Foxp3UP CD8 T cells exhibited an enhanced capacity for glucose and FA uptake as well as accumulation of intracellular lipids. Interestingly, Foxp3UP CD8 T cells compensated for the loss of mitochondrial respiration-driven ATP production by activating aerobic glycolysis. Moreover, in limiting nutrient conditions these cells engaged FA oxidation to drive OXPHOS for their energy demands. Importantly, their ability to couple glycolysis and OXPHOS allowed them to sustain proliferation under glucose restriction. Our findings demonstrate a hitherto unknown role for FOXP3 in the adaptation of CD8 T cells to TME that may enhance their efficacy in ACT.

Antibodies as drugs-a Keystone Symposia report

Therapeutic antibodies have broad indications across diverse disease states, such as oncology, autoimmune diseases, and infectious diseases. New research continues to identify antibodies with therapeutic potential as well as methods to improve upon endogenous antibodies and to design antibodies de novo. On April 27-30, 2022, experts in antibody research across academia and industry met for the Keystone symposium "Antibodies as Drugs" to present the state-of-the-art in antibody therapeutics, repertoires and deep learning, bispecific antibodies, and engineering.

Increased death and exhaustion of CD69high T cells and NK cells are associated with PD-1 antibody application in the in vitro co-culture system

Background

The application of PD-1 monoclonal antibody (mAb) helps to treat non-small cell lung cancer, but acquired resistance has emerged in clinical practice. We tested the hypothesis that acquired resistance of anti-PD-1 immunotherapy is linked to death and exhaustion of activated T and NK cell.

Methods

The co-culture system of HCC827 cells and peripheral mononuclear cells (PBMCs) was established to evaluate the effect of PD-1 mAb on the death rate and exhaustion of T and NK cell. The predisposing role of CD69 for death and exhaustion was validated by using PHA-activated PBMCs of CD69^low NSCLC patients. The 10-colour/three laser flow cytometer was used to test related markers for cell activation, death and exhaustion.

Results

We found that PD-1 mAb increase the death and exhaustion of T cells and NK cells in a dose-dependent way when PBMCs from NSCLC patients whose the percentages of CD69⁺ cells in peripheral blood T cells were greater than 5% (CD69^high NSCLC patients). By analyzing PBMCs from healthy volunteers and CD69^low NSCLC patients, we found that T cells and NK cells can be induced to die by PD-1 mAb after PHA activation, and had a tendency to raise the rate of cell exhaustion.

Conclusions

Our findings imply that increased death and exhaustion of CD69^high T cells and NK cells are associated with ineffective anti-PD-1 immunotherapy in lung cancer. The CD69 expression of T cells and NK cells may be developed as a potential predictor for acquired resistance of anti-PD-1 immunotherapy. These data may provide ideas to guide individualized medication of PD-1 mAb in NSCLC patients.

Exposure of Immunogenic Tumor Antigens in Surrendered Immunity and the Significance of Autologous Tumor Cell-Based Vaccination in Precision Medicine

The mechanisms by which immune systems identify and destroy tumors, known as immunosurveillance, have been discussed for decades. However, several factors that lead to tumor persistence and escape from the attack of immune cells in a normal immune system have been found. In the process known as immunoediting, tumors decrease their immunogenicity and evade immunosurveillance. Furthermore, tumors exploit factors such as regulatory T cells, myeloid-derived suppressive cells, and inhibitory cytokines that avoid cytotoxic T cell (CTL) recognition. Current immunotherapies targeting tumors and their surroundings have been proposed. One such immunotherapy is autologous cancer vaccines (ACVs), which are characterized by enriched tumor antigens that can escalate specific CTL responses. Unfortunately, ACVs usually fail to activate desirable therapeutic effects, and the low immunogenicity of ACVs still needs to be elucidated. This difficulty highlights the significance of immunogenic antigens in antitumor therapies. Previous studies have shown that defective host immunity triggers tumor development by reprogramming tumor antigenic expressions. This phenomenon sheds new light on ACVs and provides a potential cue to improve the effectiveness of ACVs. Furthermore, synergistically with the ACV treatment, combinational therapy, which can reverse the suppressive tumor microenvironments, has also been widely proposed. Thus, in this review, we focus on tumor immunogenicity sculpted by the immune systems and discuss the significance and application of restructuring tumor antigens in precision medicine.

Effect of M2-like macrophages of the injured-kidney cortex on kidney cancer progression

Chronic kidney disease (CKD) affects kidney cancer patients' mortality. However, the underlying mechanism remains unknown. M2-like macrophages have pro-tumor functions, also exist in injured kidney, and promote kidney fibrosis. Thus, it is suspected that M2-like macrophages in injured kidney induce the pro-tumor microenvironment leading to kidney cancer progression. We found that M2-like macrophages present in the injured kidney promoted kidney cancer progression and induced resistance to anti-PD1 antibody through its pro-tumor function and inhibition of CD8⁺ T cell infiltration. RNA-seq revealed Slc7a11 was upregulated in M2-like macrophages. Inhibition of Slc7a11 with sulfasalazine inhibited the pro-tumor function of M2-like macrophages and synergized with anti-PD1 antibody. Moreover, SLC7A11-positive macrophages were associated with poor prognosis among kidney cancer patients. Collectively, this study dissects the characteristic microenvironment in the injured kidney that contributed to kidney cancer progression and anti-PD1 antibody resistance. This insight offers promising combination therapy with anti-PD1 antibody and macrophage targeted therapy.

OXPHOS promotes apoptotic resistance and cellular persistence in TH17 cells in the periphery and tumor microenvironment

T cell proliferation and cytokine production are bioenergetically and biosynthetically costly. The inability to meet these metabolic demands results in altered differentiation, accompanied by impaired effector function, and attrition of the immune response. Interleukin-17-producing CD4 T cells (TH17s) are mediators of host defense, autoimmunity, and antitumor immunity in the setting of adoptive T cell therapy. TH17s are long-lived cells that require mitochondrial oxidative phosphorylation (OXPHOS) for effector function in vivo. Considering that TH17s polarized under standardized culture conditions are predominately glycolytic, little is known about how OXPHOS regulates TH17 processes, such as their ability to persist and thus contribute to protracted immune responses. Here, we modified standardized culture medium and identified a culture system that reliably induces OXPHOS dependence in TH17s. We found that TH17s cultured under OXPHOS conditions metabolically resembled their in vivo counterparts, whereas glycolytic cultures were dissimilar. OXPHOS TH17s exhibited increased mitochondrial fitness, glutamine anaplerosis, and an antiapoptotic phenotype marked by high BCL-XL and low BIM. Limited mitophagy, mediated by mitochondrial fusion regulator OPA-1, was critical to apoptotic resistance in OXPHOS TH17s. By contrast, glycolytic TH17s exhibited more mitophagy and an imbalance in BCL-XL to BIM, thereby priming them for apoptosis. In addition, through adoptive transfer experiments, we demonstrated that OXPHOS protected TH17s from apoptosis while enhancing their persistence in the periphery and tumor microenvironment in a murine model of melanoma. Together, our work demonstrates how metabolism regulates TH17 cell fate and highlights the potential for therapies that target OXPHOS in TH17-driven diseases.

CAR T-cells for colorectal cancer immunotherapy: Ready to go?

Chimeric antigen receptor (CAR) T-cells represent a new genetically engineered cell-based immunotherapy tool against cancer. The use of CAR T-cells has revolutionized the therapeutic approach for hematological malignancies. Unfortunately, there is a long way to go before this treatment can be developed for solid tumors, including colorectal cancer. CAR T-cell therapy for colorectal cancer is still in its early stages, and clinical data are scarce. Major limitations of this therapy include high toxicity, relapses, and an impermeable tumor microenvironment for CAR T-cell therapy in colorectal cancer. In this review, we summarize current knowledge, highlight challenges, and discuss perspectives regarding CAR T-cell therapy in colorectal cancer.

IL-10 in cancer: an essential thermostatic regulator between homeostatic immunity and inflammation - a comprehensive review

Cytokines are soluble proteins that mediate intercellular signaling regulating immune and inflammatory responses. Cytokine modulation represents a promising cancer immunotherapy approach for immune-mediated tumor regression. However, redundancy in cytokine signaling and cytokines' pleiotropy, narrow therapeutic window, systemic toxicity, short half-life and limited efficacy represent outstanding challenges for cytokine-based cancer immunotherapies. Recently, there has been interest in the paradoxical role of IL-10 in cancer, its controversial prognostic utility and novel strategies to enhance its therapeutic profile. Here, the authors review the literature surrounding the role of IL-10 within the tumor microenvironment, its prognostic correlates to cancer patient outcomes and its pro- and antitumor effects, and they assess the legitimacy of potential therapeutic strategies harnessing IL-10 by outlining the notable preclinical and clinical evidence to date.

Multimodality analysis confers a prognostic benefit of a T-cell infiltrated tumor microenvironment and peripheral immune status in patients with melanoma

BACKGROUND

We previously reported results from a phase 1 study testing intratumoral recombinant poliovirus, lerapolturev, in 12 melanoma patients. All 12 patients received anti-PD-1 systemic therapy before lerapolturev, and 11 of these 12 patients also received anti-PD-1 after lerapolturev. In preclinical models lerapolturev induces intratumoral innate inflammation that engages antitumor T cells. In the current study, prelerapolturev and postlerapolturev tumor biopsies and blood were evaluated for biomarkers of response.

METHODS

The following analyses were performed on tumor tissue (n=11): (1) flow cytometric assessment of immune cell density, (2) NanoString Digital Spatial profiling of protein and the transcriptome, and (3) bulk RNA sequencing. Immune cell phenotypes and responsiveness to in vitro stimulation, including in vitro lerapolturev challenge, were measured in peripheral blood (n=12).

RESULTS

Three patients who received anti-PD-1 therapy within 30 days of lerapolturev have a current median progression-free survival (PFS) of 2.3 years and had higher CD8+T cell infiltrates in prelerapolturev tumor biopsies relative to that of 7 patients with median PFS of 1.6 months and lower CD8+T cell infiltrates in prelerapolturev tumor biopsies. In peripheral blood, four patients with PFS 2.3 years (including three that received anti-PD-1 therapy within 30 days before lerapolturev and had higher pretreatment tumor CD8+T cell infiltrates) had significantly higher effector memory (CD8+, CCR7-, CD45RA-) but lower CD8+PD-1+ and CD4+PD-1+ cells compared with eight patients with median PFS 1.6 months. In addition, pretreatment blood from the four patients with median PFS 2.3 years had more potent antiviral responses to in vitro lerapolturev challenge compared with eight patients with median PFS 1.6 months.

CONCLUSION

An inflamed pretreatment tumor microenvironment, possibly induced by prior anti-PD-1 therapy and a proficient peripheral blood pretreatment innate immune response (antiviral/interferon signaling) to lerapolturev was associated with long term PFS after intratumoral lerapolturev in a small cohort of patients. These findings imply a link between intratumoral T cell inflammation and peripheral immune function.

TRIAL REGISTRATION NUMBER

NCT03712358.