Interferon-Gamma at the Crossroads of Tumor Immune Surveillance or Evasion

Sigma1 inhibitor suppression of adaptive immune resistance mechanisms mediated by cancer cell derived extracellular vesicles

Adaptive immune resistance in cancer describes the various mechanisms by which tumors adapt to evade anti-tumor immune responses. IFN-γ induction of programmed death-ligand 1 (PD-L1) was the first defined and validated adaptive immune resistance mechanism. The endoplasmic reticulum (ER) is central to adaptive immune resistance as immune modulatory secreted and integral membrane proteins are dependent on ER. Sigma1 is a unique ligand-regulated integral membrane scaffolding protein enriched in the ER of cancer cells. PD-L1 is an integral membrane glycoprotein that is translated into the ER and processed through the cellular secretory pathway. At the cell surface, PD-L1 is an immune checkpoint molecule that binds PD-1 on activated T-cells and blocks anti-tumor immunity. PD-L1 can also be incorporated into cancer cell-derived extracellular vesicles (EVs), and EV-associated PD-L1 can inactivate T-cells within the tumor microenvironment. Here, we demonstrate that a selective small molecule inhibitor of Sigma1 can block IFN-γ mediated adaptive immune resistance in part by altering the incorporation of PD-L1 into cancer cell-derived EVs. Sigma1 inhibition blocked post-translational maturation of PD-L1 downstream of IFN-γ/STAT1 signaling. Subsequently, EVs released in response to IFN-γ stimulation were significantly less potent suppressors of T-cell activation. These results suggest that by reducing tumor derived immune suppressive EVs, Sigma1 inhibition may promote antitumor immunity. Sigma1 modulation presents a novel approach to regulating the tumor immune microenvironment by altering the content and production of EVs. Altogether, these data support the notion that Sigma1 may play a role in adaptive immune resistance in the tumor microenvironment.

BRAF/MEK Inhibition Induces Cell State Transitions Boosting Immune Checkpoint Sensitivity in BRAFV600E -mutant Glioma

Resistance to BRAF plus MEK inhibition (BRAFi+MEKi) in BRAFV600E-mutant gliomas drives rebound, progression, and high mortality, yet it remains poorly understood. This study addresses the urgent need to develop treatments for BRAFi+MEKi-resistant glioma in novel mouse models and patient-derived materials. BRAFi+MEKi reveals glioma plasticity by heightening cell state transitions along glial differentiation trajectories, giving rise to astrocyte- and immunomodulatory oligodendrocyte (OL)-like states. PD-L1 upregulation in OL-like cells links cell state transitions to tumor evasion, possibly orchestrated by Galectin-3. BRAFi+MEKi induces interferon response signatures, tumor infiltration, and suppression of T cells. Combining BRAFi+MEKi with immune checkpoint inhibition enhances survival in a T cell-dependent manner, reinvigorates T cells, and outperforms individual or sequential therapies in mice. Elevated PD-L1 expression in BRAF-mutant versus BRAF-wildtype glioblastoma supports the rationale for PD-1 inhibition in patients. These findings underscore the potential of targeting glioma plasticity and highlight combination strategies to overcome therapy resistance in BRAFV600E-mutant HGG.

CD3xHER2 bsAb-Mediated Activation of Resting T-cells at HER2 Positive Tumor Clusters Is Sufficient to Trigger Bystander Eradication of Distant HER2 Negative Clusters Through IFNγ and TNFα

Bispecific antibodies (bsAbs) bridging CD3 on T-cells to tumor-associated antigens (TAA) on tumor cells can direct T-cell immunity to solid tumors. "Bystander killing", where T-cell targeting of TAA-positive tumor cells also leads to the eradication of TAA-negative cells, may overcome TAA heterogeneity. While bystander activity of activated, engineered T-cells has been shown to be robust and wide-reaching, spatiotemporal aspects of bsAb-mediated bystander activity are unresolved. Here, we developed a model where breast cancer tumoroids varying in HER2 expression were printed in to extracellular matrix (ECM) scaffolds. We generated (1) mixed tumors containing different ratios of HER2+ and HER2- tumor cells, and (2) HER2+ and HER2- tumoroids spaced at different distances within the ECM scaffold. Subsequently, tumors were exposed to peripheral blood-derived T-cells in the presence of CD3xHER2 bsAbs. We find that CD3xHER2 bsAb-mediated interaction of resting, nonactivated T-cells with HER2+ tumor cells is sufficient (1) to eliminate 50% HER2- cells in mixed tumor areas, and (2) to eradicate distant HER2- tumor areas. Such bystander killing involves paracrine IFNγ and TNFα activity but does not require T-cell accumulation in HER2- areas. These findings indicate that bystander eradication of TAA-negative cells can significantly contribute to bsAb therapy for solid tumors.

Research Hotspots of Interferon Gamma in the Treatment of Lung Cancer: A Bibliometric Analysis Based on CiteSpace

Interferon-gamma (IFN-γ) is an important cytokine associated with antitumor immunity and has been implicated in the pathogenesis and progression of lung cancer. Nevertheless, no bibliometric analyses have been published in this field to date, and thus we aim to address this gap in knowledge. A search of the Web of Science (WOS) for literature related to the treatment of lung cancer with IFN-γ was conducted from 2002 to 2024. The extracted information from the included articles was subjected to visual analysis, and network diagrams were generated using software such as CiteSpace and VOSviewer. In total, 589 articles related to the treatment of lung cancer with IFN-γ were included in WOS between 2002 and 2024. The number of articles and citation frequency generally showed an increasing trend year by year. The United States and the University of California are the countries and institutions with the largest number of articles. The researcher who made the largest contribution to this field was Xin Cai from China (6). The Journal for ImmunoTherapy of Cancer published the largest number of relevant papers in the field (16 papers, IF = 12.469). The research hotspots in the field of immune escape in recent years have been IFN-γ, mechanism, immune checkpoints, and microtumor inhibitors. The field of IFN-γ treatment of lung cancer is evolving at a rapid pace. The current research focus within this field is on elucidating the mechanism of IFN-γ treatment of lung cancer, investigating the role of immune checkpoint inhibitors, and examining the tumor microenvironment and other pertinent topics.

USP19 deficiency enhances T-cell-mediated antitumor immunity by promoting PD-L1 degradation in colorectal cancer

Colorectal cancer (CRC) is characterized by a highly immunosuppressive tumor microenvironment, which limits the effectiveness of current immunotherapies. Identifying strategies to overcome this resistance is critical for improving treatment outcomes. In this study, we discovered that USP19 plays a pivotal role in regulating T-cell-mediated antitumor immunity through a CRISPR/Cas9 sgRNA library screen and co-culture assays with activated T cells. We demonstrated that USP19 deficiency significantly enhances the susceptibility to T cell-mediated cytotoxicity in CRC cells, organoids, and mouse models. Transcriptomic sequencing (RNA-seq) revealed activation of the PD-1 pathway in tumor with USP19-deficiency cells. Mechanistic investigations revealed that USP19 directly stabilizes PD-L1 by binding to its intracellular domain and preventing its degradation via K48-linked ubiquitination and proteasomal pathways. Clinically, USP19 expression was found to be significantly elevated in CRC tissues and was positively associated with PD-L1 levels, advanced tumor grade, poor differentiation, and TP53 mutations, highlighting its potential as a biomarker for aggressive CRC. Importantly, in vivo experiments demonstrated that targeting USP19, in combination with αPD-L1 therapy, synergistically suppressed CRC progression. This combination not only reduced PD-L1 levels but also enhanced CD8+ T-cell activation and GzmB infiltration, resulting in robust antitumor effects. These findings establish USP19 as a key driver of immune evasion in CRC and suggest that targeting USP19 could enhance the efficacy of immunotherapy, providing a promising new avenue for CRC treatment.

The dynamic role of ferroptosis in cancer immunoediting: Implications for immunotherapy

Currently, cancer immunotherapy strategies are primarily formulated based on the patient's present condition, representing a "static" treatment approach. However, cancer progression is inherently "dynamic," as the immune environment is not fixed but undergoes continuous changes. This dynamism is characterized by the ongoing interactions between tumor cells and immune cells, which ultimately lead to alterations in the tumor immune microenvironment. This process can be effectively elucidated by the concept of cancer immunoediting, which divides tumor development into three phases: "elimination," "equilibrium," and "escape." Consequently, adjusting immunotherapy regimens based on these distinct phases may enhance patient survival and improve prognosis. Targeting ferroptosis is an emerging area in cancer immunotherapy, and our findings reveal that the antioxidant systems associated with ferroptosis possess dual roles, functioning differently across the three phases of cancer immunoediting. Therefore, this review delve into the dual role of the ferroptosis antioxidant system in tumor development and progression. It also propose immunotherapy strategies targeting ferroptosis at different stages, ultimately aiming to illuminate the significant implications of targeting ferroptosis at various phases for cancer immunotherapy.

Dendritic cell maturation in cancer

Dendritic cells (DCs) are specialized antigen-presenting cells that are present at low abundance in the circulation and tissues; they serve as crucial immune sentinels by continually sampling their environment, migrating to secondary lymphoid organs and shaping adaptive immune responses through antigen presentation. Owing to their ability to orchestrate tolerogenic or immunogenic responses to a specific antigen, DCs have a pivotal role in antitumour immunity and the response to immune checkpoint blockade and other immunotherapeutic approaches. The multifaceted functions of DCs are acquired through a complex, multistage process called maturation. Although the role of inflammatory triggers in driving DC maturation was established decades ago, less is known about DC maturation in non-inflammatory contexts, such as during homeostasis and in cancer. The advent of single-cell technologies has enabled an unbiased, high-dimensional characterization of various DC states, including mature DCs. This approach has clarified the molecular programmes associated with DC maturation and also revealed how cancers exploit these pathways to subvert immune surveillance. In this Review, we discuss the mechanisms by which cancer disrupts DC maturation and highlight emerging therapeutic opportunities to modulate DC states. These insights could inform the development of DC-centric immunotherapies, expanding the arsenal of strategies to enhance antitumour immunity.

A myeloid IFN gamma response gene signature correlates with cancer prognosis

BACKGROUND

The IFN-γ cytokine plays a dual role in anti-tumor immunity, enhancing immune defense against cancer cells while promoting tumor survival and progression. Its influence on prognosis and therapeutic responses across cancer types remains unclear.

OBJECTIVE

This study aimed to perform a pan-cancer analysis of IFN-γ response genes to determine their prognostic significance and evaluate their impact on clinical outcomes and anti-PD1 immunotherapy responses.

METHODS

Using multiple datasets, 46 IFN-γ response genes were identified as prognostic for disease-specific survival, and their expression was used to construct the IFN-γ Response Gene Network Signature (IFGRNS) score. The prognostic and therapeutic relevance of the IFGRNS score was assessed across cancer types, considering tumor pathology, genomic alterations, tumor mutation burden, and microenvironment. Single-cell transcriptomic analysis identified cellular contributors, and a murine pancreatic cancer (PAN02) model was used to validate findings with anti-PD1 therapy.

RESULTS

The IFGRNS score emerged as a robust prognostic indicator of survival, with higher scores correlating with worse outcomes in most cancer types. The prognostic significance of the score was influenced by factors such as cancer type, tumor pathology, and the tumor microenvironment. Single-cell analysis revealed that myeloid cells, particularly the M2 macrophage subtype, demonstrated high levels of IFGRNS expression, which was associated with tumor progression. A negative correlation was observed between the IFGRNS score and outcomes to anti-PD1 immunotherapy in urologic cancers, where patients with higher scores showed worse prognosis and lower response rates to therapy. Experimental validation in the PAN02 murine model confirmed that anti-PD1 therapy significantly reduced tumor size and IFGRNS expression in M2 macrophages, supporting the clinical findings.

CONCLUSIONS

The IFGRNS score is a novel prognostic indicator for survival and therapeutic responses in cancer. These findings underline the complexity of IFN-γ signaling and suggest potential applications for the IFGRNS score in cancer diagnosis, prognosis, and immunotherapy. Novelty & impact statements: IFN-γ response genes play a significant role in tumour biology, yet comprehensive analysis across various cancers is limited. This study identifies a novel prognostic biomarker, the IFGRNS score, which is elevated in myeloid lineage cells and correlates with survival across multiple cancers. The IFGRNS score is also associated with tumour pathology, immune microenvironment, and immunotherapy response, highlighting its diagnostic and therapeutic potential in cancer management.

KEY POINTS

IFN-γ cytokine plays a dual role in cancer, aiding immune defense but also promoting tumor progression. A novel IFGRNS score, based on 46 IFN-γ response genes, was identified as a strong prognostic marker for survival across cancer types. Higher IFGRNS scores correlate with worse prognosis and reduced response to anti-PD1 immunotherapy, particularly in urologic cancers. M2 macrophages were identified as key contributors to high IFGRNS scores, associated with tumor progression. Findings were validated in a murine cancer model, highlighting the potential of the IFGRNS score for cancer prognosis and therapy guidance.

Endothelial barrier disruptive effect of IFN-Ƴ and TNF-α: Synergism of pro-inflammatory cytokines

Crosstalk and synergy between interferon-γ (IFN-Ƴ) and tumor necrosis factor-α (TNF-α) in endothelial cells have previously been documented, however, there is an absence of articles reviewing the synergistic effect of IFN-Ƴ and TNF-α in regulating the endothelial barrier function. This review discusses the regulatory mechanisms and recent evidence of the synergism of IFN-γ and TNF-α in causing destabilization of endothelial junctions in various clinical studies and preclinical models. Articles were retrieved from electronic databases such as Web of Science, PubMed, Google Scholar, and Scopus. The search terms used were "interferon", "interferon-gamma", "tumor necrosis factor-α", "vascular inflammation", "endothelial barrier", "endothelial permeability" and "synergism". We selected articles published between 2004 and 2024. Through the Rho-associated protein kinase (ROCK) and p38 mitogen-activated protein (MAP) kinase pathways, our results showed that IFN-γ controls the remodeling of actin and the stability of junctions. In comparison to IFN-γ, the signaling cascades triggered by TNF-α involve a variety of pathways such as nuclear factor-kappa B (NF-κB), small GTPases, tyrosine kinases, integrin receptors, and barrier-stabilizing molecules such as Ras-related proteins 1A (Rap1A) and Rac family small GTPase 1 (Rac1). In the context of IFN-γ and TNF-α synergism, combined IFN-γ and TNF-α alter adherens and tight junctions. It is deduced that c-Jun N-terminal kinase (JNK), signal transducers and activators of transcription (STAT1), and caspase signaling pathways regulate endothelial barrier disruption caused by IFN-γ and TNF-α. Collectively, the mechanism underlying the synergistic action of IFN-γ and TNF-α is still lacking. Future work is needed to explore the crosstalk pathways of IFN-γ and TNF-α involved in the regulation of endothelial barrier function such as modulation of extracellular matrix (ECM) structure, involvement of tyrosine kinases and roles of small GTPases.

Friend or foe of tripartite motif-containing protein 21 in cardiovascular disease: A review

As an E3 ubiquitin ligase and an Fc receptor, tripartite motif-containing protein 21 (TRIM21) plays a crucial role in immune defense, signal transduction, and cellular regulation. TRIM21 is widely expressed in various tissues, but it is particularly abundant in cardiovascular tissues and is involved in the pathogenesis of various cardiovascular diseases (CVDs). However, although TRIM21 is involved in the regulation of several key molecular pathways in the immune system, its specific role in CVD remains unclear. In this review, we comprehensively summarize the regulatory role of TRIM21 in signaling pathways and discuss the function of TRIM21 in CVD, to provide a systematic understanding of this important protein in CVD and offer insights for further research into the pathogenesis of CVD and its potential applications.

A live attenuated SARS-CoV-2 vaccine constructed by dual inactivation of NSP16 and ORF3a

BACKGROUND

Live attenuated vaccines against SARS-CoV-2 activate all phases of host immunity resembling a natural infection and they block viral transmission more efficiently than existing vaccines in human use. In our prior work, we characterised an attenuated SARS-CoV-2 variant, designated d16, which harbours a D130A mutation in the NSP16 protein, inactivating its 2'-O-methyltransferase function. The d16 variant has demonstrated an ability to induce both mucosal and sterilising immunity in animal models. However, further investigation is required to identify any additional modifications to d16 that could mitigate concerns regarding potential virulence reversion and the suboptimal regulation of the proinflammatory response.

METHODS

Mutations were introduced into molecular clone of SARS-CoV-2 and live attenuated virus was recovered from cultured cells. Virological, biochemical and immunological assays were performed in vitro and in two animal models to access the protective efficacies of the candidate vaccine strain.

FINDINGS

Here we describe evaluation of a derivative of d16. We further modified the d16 variant by inverting the open reading frame of the ORF3a accessory protein, resulting in the d16i3a strain. This modification is anticipated to enhance safety and reduce pathogenicity. d16i3a appeared to be further attenuated in hamsters and transgenic mice compared to d16. Intranasal vaccination with d16i3a stimulated humoural, cell-mediated and mucosal immune responses, conferring sterilising protection against SARS-CoV-2 Delta and Omicron variants in animals. A version of d16i3a expressing the XBB.1.16 spike protein further expanded the vaccine's protection spectrum against circulating variants. Notably, this version has demonstrated efficacy as a booster in hamsters, providing protection against Omicron subvariants and achieving inhibition of viral transmission.

INTERPRETATION

Our work established a platform for generating safe and effective live attenuated vaccines by dual inactivation of NSP16 and ORF3a of SARS-CoV-2.

FUNDING

This work was supported by National Key Research and Development Program of China (2021YFC0866100, 2023YFC3041600, and 2023YFE0203400), Hong Kong Health and Medical Research Fund (COVID190114, CID-HKU1-9, and 23220712), Hong Kong Research Grants Council (C7142-20GF and T11-709/21-N), Hong Kong Innovation and Technology Commission grant (MHP/128/22), Guangzhou Laboratory (EKPG22-01) and Health@InnoHK (CVVT). Funding sources had no role in the writing of the manuscript or the decision to submit it for publication.

Axl Regulation of NK Cell Activity Creates an Immunosuppressive Tumor Immune Microenvironment in Head and Neck Cancer

Background: Head and neck cancer (HNC) evades immune responses by manipulating the tumor immune microenvironment (TIME). Tumor-bound Axl has been implicated in promoting an immunosuppressive TIME in HNC, though its precise role remains unclear. Understanding Axl's contribution to immune evasion in HNC could lead to the identification of new therapeutic targets; therapies directed at these targets could be combined with and thereby enhance immunotherapies. Results: Using Axl knockout (Axl KO) cell lines derived from the immunologically "cold" MOC2 mouse model, we found that Axl loss delayed tumor growth in immunocompetent mice. This was accompanied by reduced immunosuppressive cells, including MDSCs, Tregs, B cells, and neutrophils, and increased infiltration of cytotoxic CD8 T cells and NK cells. To identify the immune population(s) responsible for these changes, Axl KO tumors were implanted in immune-deficient mice. Axl KO tumor growth in athymic nude mice (which lack T cells) was unchanged, whereas tumor growth in NCG mice (which lack NK cells) was rescued, suggesting that NK cells mediate the Axl KO tumor growth delay. Further, Axl loss enhanced NK cell cytotoxicity in vitro and in vivo, and NK cell depletion reversed delayed Axl KO tumor growth. Mechanistically, Axl KO tumors showed decreased expression of CD73 and CCL2, which inhibit NK cells, and increased expression of CCL5 and CXCL10, which promote NK cell recruitment and activation. Conclusions: These novel findings suggest that tumor-bound Axl fosters an immunosuppressive TIME by inhibiting NK cell recruitment and function, thereby promoting tumor growth. Targeting Axl may enhance NK cell-mediated tumor killing and improve immunotherapy efficacy in HNC.

Immune checkpoint blockade for cancer therapy: current progress and perspectives

Dysfunction of anti-tumor immune responses is crucial for cancer progression. Immune checkpoint blockade (ICB), which can potentiate T cell responses, is an effective strategy for the normalization of host anti-tumor immunity. In recent years, immune checkpoints, expressed on both tumor cells and immune cells, have been identified; some of them have exhibited potential druggability and have been approved by the US Food and Drug Administration (FDA) for clinical treatment. However, limited responses and immune-related adverse events (irAEs) cannot be ignored. This review outlines the development and applications of ICBs, potential strategies for overcoming resistance, and future directions for ICB-based cancer immunotherapy.

Chitosan/γ-PGA nanoparticles and IFN-γ immunotherapy: A dual approach for triple-negative breast cancer treatment

Interferon-γ (IFN-γ) is a key mediator in antitumor immunity and immunotherapy responses, yet its clinical applications remain restricted to chronic granulomatous disease and malignant osteopetrosis. IFN-γ effectiveness as a standalone treatment has shown limited success in clinical trials and its potential for synergistic effects when combined with immunotherapies is under clinical exploration. A particularly compelling combination is that of IFN-γ with Toll-like receptor (TLR) agonists that holds significant promise for cancer treatment. Previously, we demonstrated chitosan (Ch)/poly(γ-glutamic acid) (γ-PGA) nanoparticles (NPs), known to activate TLRs, as adjuvants to radiotherapy by remodeling breast tumor microenvironment and systemic immunosuppression. These immunomodulatory abilities make Ch/γ-PGA NPs promising adjuvants to IFN-γ-based therapies. Here, we addressed the synergistic therapeutic potential of combining Ch/γ-PGA NPs with IFN-γ therapy in the 4T1 orthotopic breast tumor mouse model. While control animals (placebo-treated) had progressive tumor growth and lung metastases, those treated with either NPs or IFN-γ alone had a significant slower tumor growth. Remarkably, primary tumor growth was halted throughout the duration of the treatment when both treatments were combined. Although the animals did not achieve durable complete responses upon treatment withdrawal, it was notable that the NPs plus IFN-γ group presented a lower lung metastatic burden compared to other groups. Systemically, the combination therapy slightly attenuated immunosuppression and the percentage of splenic myeloid cells, while increased the percentage of T helper 1 cells and of cytotoxic T cells. Overall, this proof-of-concept study suggests that Ch/γ-PGA NPs potentiate IFN-γ effects to reduce tumor progression, presenting a novel approach for anticancer strategies.

Immunological Network Signature of Naïve Non-Oncogene-Addicted Non-Small Cell Lung Cancer Patients Treated with Anti-PD1 Therapy: A Pilot Study

Background/Objectives: Non-small cell lung cancer (NSCLC) patients without gene driver mutations receive anti-PD1 treatments either as monotherapy or in combination with chemotherapy based on PD-L1 expression in tumor tissue. Anti-PD1 antibodies target various immune system components, perturbing the balance between immune cells and soluble factors. In this study, we identified the immune signatures of NSCLC patients associated with different clinical outcomes through network analysis. Methods: Twenty-seven metastatic NSCLC patients were assessed at baseline for the levels of circulating CD137+ T cells (total, CD4+, and CD8+) via cytofluorimetry, along with 14 soluble checkpoints and 20 cytokines through Luminex analysis. Hierarchical clustering and connectivity heatmaps were executed, analyzing the response to therapy (R vs. NR), performance status (PS = 0 vs. PS > 0), and overall survival (OS < 3 months vs. OS > 3 months). Results: The clustering of immune checkpoints revealed three groups with a significant differential proportion of six checkpoints between patients with PS = 0 and PS > 0 (p < 0.0001). Furthermore, significant pairwise correlations among immune factors evaluated in R were compared to the lack of significant correlations among the same immune factors in NR patients and vice versa. These comparisons were conducted for patients with PS = 0 vs. PS > 0 and OS < 3 months vs. OS > 3 months. The results indicated that NR with PS > 0 and OS ≤ 3 months exhibited an inflammatory-specific signature compared to the contrasting clinical conditions characterized by a checkpoint molecule-based network (p < 0.05). Conclusions: Identifying various connectivity immune profiles linked to response to therapy, PS, and survival in NSCLC patients represents significant findings that can optimize therapeutic choices.

Improving IL12 immunotherapy in glioblastoma by targeting the long noncoding RNA INCR1

PURPOSE

The potent antitumor effects of interleukin 12 (IL12) gene therapy in glioblastoma (GBM) are significantly attenuated by the highly immunosuppressive microenvironment and the upregulation of the PD-1/PD-L1 immune checkpoint. However, combining IL12 gene therapy with PD-1/PD-L1 inhibitors failed to improve efficacy. This study aims to assess the effects of silencing the immunosuppressive long noncoding RNA INCR1 when combined with IL12 therapy.

METHODS

RNAscope in situ hybridization was performed to analyze INCR1 and PD-L1 expression in tumor tissues from GBM patients pre- and post-IL12 gene therapy. Quantitative PCR was used to analyze immunosuppressive gene expression in patient-derived GBM cells co-cultured with immune cells stimulated with IL12. The effects of INCR1 and PD-L1 silencing on the expression of immunosuppressive genes were evaluated by RNA sequencing. 3D-cytotoxicity assays were performed to assess the activity of immune cells against GBM tumor cells.

RESULTS

INCR1 and PD-L1 expression was upregulated in tumor tissue from GBM patients treated with IL12 gene therapy compared to the tumor tissue of the same patients before the IL12 treatment. Co-culture of patient-derived GBM cells with IL12-stimulated immune cells increased the expression of several immunosuppressive genes. Knocking down INCR1 was more effective than silencing PD-L1 in reducing the expression of multiple immunosuppressive genes. INCR1 silencing improved IL12-mediated immune cell antitumor activity compared to monoclonal antibodies targeting the PD-1/PD-L1 immune checkpoint signaling.

CONCLUSION

INCR1 silencing affects more immune evasive pathways than PD-L1. Targeting INCR1 may represent a valid approach to improve the efficacy of IL12 therapy in GBM.

Reduced Serum PD-L1 and Markers of Inflammation in Response to Alternate Day Fasting With a Low-Carbohydrate Intervention: A Secondary Analysis of a Single-Arm Trial

This secondary analysis aimed to examine the effect of a single-arm alternate day fasting intervention with a 30% low-carbohydrate diet on biomarkers of inflammation and immune activation in adults with obesity. A 12-week weight-loss period was followed by a 12-week weight maintenance period. Anthropometrics and blood samples were collected at baseline and weeks 12 and 24. Multiplex assay was used to measure serum biomarkers including programmed death ligand 1 (PD-L1), interleukin 8 (IL-8), IL-1 receptor antagonist (IL-1ra), chemokine ligand (CCL)2, CCL4, interferon gamma (IFnγ), IFNγ-induced protein 10 (IP-10), and cluster of differentiation 40 ligand (CD40-L). In 28 participants, body weight and fat mass decreased during the weight-loss period but stabilized during the weight maintenance period. Serum PD-L1 decreased from baseline to week 12 (P = 0.005) but not at week 24. Moreover, IL-1ra and CCL4 concentrations decreased from baseline to week 24 (P < 0.001 and P < 0.008, respectively). Changes were not significant for in CCL2, IL-8, CD40-L, IFNγ, or IP-10. In conclusion, alternate day fasting-low carbohydrate modulates circulating immune biomarkers, which may be relevant to diabetes, cancer, and autoimmunity. This trial was registered at clinicaltrials.gov as NCT03528317 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6934424/).

Exploring the impact of interferon-gamma single nucleotide polymorphisms on HTLV-1 infection: Unraveling genetic influences in viral pathogenesis

Human T-lymphotropic virus-1 (HTLV-1) induces neoplastic adult T-cell leukemia/lymphoma (ATLL) and neurological HTLV-1 associated myelopathy (HAM) in approximately 3 %-5 % of infected individuals. The precise factors that facilitate disease manifestation are still unknown; interaction between the virus and the host's immune response is key. Cytokines regulates physiological activities and their dysregulation may initiate the pathogenesis of various malignant and infectious diseases. Genetic variations, particularly polymorphisms in gene regulatory regions, lead to varying cytokine production patterns. Interferon-gamma (IFN-γ), a key cytokine in HTLV-1 infection, is a signature cytokine for T-helper 1 (Th1) cells that interferes with viral replication and enhances innate and adaptive immune responses during viral infections. The IFNG gene possesses several single nucleotide polymorphisms (SNPs), among which the + 874 A/T SNP has been widely studied for its functional role in HTLV-1 infection. The purpose of this review was to provide insight into the impact of IFNG SNPs on HTLV-1 Infection.

T cell related osteoimmunology in fracture healing: Potential targets for augmenting bone regeneration

Last decade has witnessed increasing evidence which highlights the roles of immune cells in bone regeneration. Numerous immune cell types, including macrophages, T cells, and neutrophils are involved in fracture healing by orchestrating a series of events that modulate bone formation and remodeling. In this review, the role of T cell immunity in fracture healing has been summarized, and the modulatory effects of T cell immunity in inflammation, bone formation and remodeling have been highlighted. The review also summarizes the specific roles of different T cell subsets, including CD4+ T cells, CD8+ T cells, regulatory T cells, T helper 17 cells, and γδ T cells in modulating fracture healing. The current therapeutics targeting T cell immunity to enhance fracture healing have also been reviewed, aiming to provide insights from a translational standpoint. Overall, this work discusses recent advances and challenges in the interdisciplinary research field of T cell related osteoimmunology and its implications in fracture healing.

The translational potential of this article

Delayed unions or non-unions of bone fractures remain a challenge in clinical practice. Developing a deep understanding of the roles of immune cells, including T cells, in fracture healing will facilitate the advancement of novel therapeutics of fracture nonunion. This review summarizes the current understanding of different T cell subsets involved in various phases of fracture healing, providing insights for targeting T cells as an alternative strategy to enhance bone regeneration.

Viral influencers: deciphering the role of endogenous retroviral LTR12 repeats in cellular gene expression

The human genome is like a museum of ancient retroviral infections. It contains a large number of endogenous retroviruses (ERVs) that bear witness to past integration events. About 5,000 of them are so-called long terminal repeat 12 (LTR12) elements. Compared with 20,000 human genes, this is a remarkable number. Although LTR12 elements can act as promoters or enhancers of cellular genes, the function of most of these retroviral elements has remained unclear. In our mini-review, we show that different LTR12 elements share many similarities, including common transcription factor binding sites. Furthermore, we summarize novel insights into the epigenetic mechanisms governing their silencing and activation. Specific examples of genes and pathways that are regulated by LTR12 loci are used to illustrate the regulatory network built by these repetitive elements. A particular focus is on their role in the regulation of antiviral immune responses, tumor cell proliferation, and senescence. Finally, we describe how a targeted activation of this fascinating ERV family could be used for diagnostic or therapeutic purposes.

Identification of three subtypes of thyroid cancer based on IFN-γ-related genes to reveal their prognostic characteristics

BACKGROUND

Thyroid cancer is one of the deadliest malignancies. Increasing evidence suggests that interferon-γ (IFN-γ) plays an important role in anti-tumor immunity and its treatment. However, the effectiveness of classifying, predicting prognosis, and immunotherapy for thyroid cancer based on IFN-γ-related genes has not been discovered.

METHODS

We used the Gene Set Enrichment Analysis (GSEA) database to obtain IFN-γ-related genes and classified thyroid cancer patients from The Cancer Genome Atlas (TCGA). We systematically explored the differences among various thyroid cancer subtypes from multiple perspectives, such as Kaplan-Meier survival analysis, tumor mutation analysis, immune analysis, enrichment analysis, and drug sensitivity analysis. Finally, we screened some potential drugs suitable for each population.

RESULTS

Through clustering analysis, we obtained three thyroid cancer subtypes with different IFN-γ-related gene expression levels. The survival analysis results showed significant survival differences among these three subtypes. In addition, gene mutation analysis in different subtypes found that BRAF, TTN, and TG were the top three genes with the highest mutation frequency in the three subtypes, which may be related to their prognosis. Cluster 1 and cluster 2 were the two subtypes with the greatest difference in immune cell infiltration levels, and the differentially expressed genes were mainly enriched in immune-related biological processes or signaling pathways such as leukocyte-mediated immunity, regulation of T cell activation, and chemokine signaling pathway. Eighteen compounds such as Cyclopamine, Erlotinib, FH535, Imatinib, and A-770,041 were selected as potential therapeutic drugs in this study, and their sensitivity to different subtypes varied.

CONCLUSION

Based on bioinformatics analysis, we discovered a new classification method based on IFN-γ genes, which could divide thyroid cancer patients into three populations with significant characteristics. Different populations had different mutation patterns, immune infiltration levels, and candidate therapeutic drugs.

Anti-hepatoma effect of homologous delivery of doxorubicin by HepG2 cells

Compared to conventional polymer-based and biomaterial carriers, cells as vehicles for delivering bioactive molecules in the treatment of tumor diseases offer characteristics such as non-toxicity, biocompatibility, low immunogenicity, and prolonged in vivo circulation. However, the focus of current cell drug delivery systems predominantly lies on live cells, such as red blood cells, white blood cells and others. Here, a drug delivery strategy targeting liver cancer utilizing cryo-shocked liver cancer cells (HepG2) as carriers was presented, and non-proliferative HepG2 cells particles loaded with DOX (HepG2-DOX) was effectively prepared, which has good homologous targeting. Subsequent in vitro and in vivo experiments demonstrated the non-proliferative and non-pathogenic nature of this drug delivery system. The outcomes of in vitro experiments revealed that the inhibitory effect of HepG2-DOX on HepG2 was approximately five times higher than that of free DOX, with the IC50 value of HepG2-DOX being 0.0739 µg/mL and free DOX being 0.3606 µg/mL. Furthermore, in comparison to the positive DOX group, the HepG2-DOX group has a very significant advantage in tumor inhibition rate (91.34 % vs. 64.20 %). Cell uptake experiments indicated significant HepG2-DOX uptake by HepG2 cells compared to 4T1, LO2, and Raw cell groups, highlighting the excellent cell specificity of HepG2-DOX. Fluorescence imaging conducted in mice following the administration of HepG2-DOX demonstrated prompt drug localization within the tumor region, highlighting exceptional in vivo targeting precision. To sum up, this study introduced a novel strategy utilizing cryo-shocked liver cancer cells as a drug delivery system, effectively treating liver tumor by enhancing tumor targeting specificity.

Alternative Splicing as a Modulator of the Interferon-Gamma Pathway

Interferon-gamma (IFN-γ) is a critical cytokine that plays a pivotal role in immune system regulation. It is a key mediator of both cellular defense mechanisms and antitumor immunity. As the sole member of the type II interferon family, IFN-γ modulates immune responses by activating macrophages, enhancing natural killer cell function, and regulating gene expression across multiple cellular processes. Alternative splicing is a post-transcriptional gene expression regulatory mechanism that generates multiple mature messenger RNAs from a single gene, dramatically increasing proteome diversity without the need of a proportional genome expansion. This process occurs in 90-95% of human genes, with alternative splicing events allowing for the production of diverse protein isoforms that can have distinct-or even opposing-functional properties. Alternative splicing plays a crucial role in cancer immunology, potentially generating tumor neoepitopes and modulating immune responses. However, how alternative splicing affects IFN-γ's activity is still poorly understood. This review explores how alternative splicing regulates the expression and function of both upstream regulators and downstream effectors of IFN-γ, revealing complex mechanisms of gene expression and immune response modulation. Key transcription factors and signaling molecules of the IFN-γ pathway are alternatively spliced, and alternative splicing can dramatically alter IFN-γ signaling, immune cell function, and response to environmental cues. Specific splice variants can enhance or inhibit IFN-γ-mediated immune responses, potentially influencing cancer immunotherapy, autoimmune conditions, and infectious disease outcomes. The emerging understanding of these splicing events offers promising therapeutic strategies for manipulating immune responses through targeted molecular interventions.

H3.3-G34R Mutation-Mediated Epigenetic Reprogramming Leads to Enhanced Efficacy of Immune Stimulatory Gene Therapy in Diffuse Hemispheric Gliomas

Diffuse hemispheric glioma (DHG), H3 G34-mutant, representing 9-15% of cases, are aggressive Central Nervous System (CNS) tumors with poor prognosis. This study examines the role of epigenetic reprogramming of the immune microenvironment and the response to immune-mediated therapies in G34-mutant DHG. To this end, we utilized human G34-mutant DHG biopsies, primary G34-mutant DHG cultures, and genetically engineered G34-mutant mouse models (GEMMs). Our findings show that the G34 mutation alters histone marks' deposition at promoter and enhancer regions, leading to the activation of the JAK/STAT pathway, which in turn results in an immune-permissive tumor microenvironment. The implementation of Ad-TK/Ad-Flt3L immunostimulatory gene therapy significantly improved median survival, and lead to over 50% long term survivors. Upon tumor rechallenge in the contralateral hemisphere without any additional treatment, the long-term survivors exhibited robust anti-tumor immunity and immunological memory. These results indicate that immune-mediated therapies hold significant potential for clinical translation in treating patients harboring H3.3-G34 mutant DHGs, offering a promising strategy for improving outcomes in this challenging cancer subtype affecting adolescents and young adults (AYA).

STATEMENT OF SIGNIFICANCE

This study uncovers the role of the H3.3-G34 mutation in reprogramming the tumor immune microenvironment in diffuse hemispheric gliomas. Our findings support the implementation of precision medicine informed immunotherapies, aiming at improving enhanced therapeutic outcomes in adolescents and young adults harboring H3.3-G34 mutant DHGs.

Turning cold into hot: emerging strategies to fire up the tumor microenvironment

The tumor microenvironment (TME) is a complex, highly structured, and dynamic ecosystem that plays a pivotal role in the progression of both primary and metastatic tumors. Precise assessment of the dynamic spatiotemporal features of the TME is crucial for understanding cancer evolution and designing effective therapeutic strategies. Cancer is increasingly recognized as a systemic disease, influenced not only by the TME, but also by a multitude of systemic factors, including whole-body metabolism, gut microbiome, endocrine signaling, and circadian rhythm. In this review, we summarize the intrinsic, extrinsic, and systemic factors contributing to the formation of 'cold' tumors within the framework of the cancer-immunity cycle. Correspondingly, we discuss potential strategies for converting 'cold' tumors into 'hot' ones to enhance therapeutic efficacy.

Innovations in cancer immunotherapy: A comprehensive overview of recent breakthroughs and future directions

A major advance in cancer treatment has been the development and refinement of cancer immunotherapy. The discovery of immunotherapies for a wide range of cancers has revolutionized cancer treatment paradigms. Despite relapse or refractory disease, immunotherapy approaches can prolong the life expectancy of metastatic cancer patients. Multiple therapeutic approaches and agents are currently being developed to manipulate various aspects of the immune system. Oncolytic viruses, cancer vaccines, adoptive cell therapies, monoclonal antibodies, cytokine therapies, and inhibitors of immune checkpoints have all proven successful in clinical trials. There are several types of immunotherapeutic approaches available for treating cancer, and others are being tested in preclinical and clinical settings. Immunotherapy has proven successful, and many agents and strategies have been developed to improve its effectiveness. The purpose of this article is to present a comprehensive overview of current immunotherapy approaches used to treat cancer. Cancer immunotherapy advancements, emerging patterns, constraints, and potential future breakthroughs are also discussed.

Interferon therapy in alpha and Delta variants of SARS-CoV-2: The dichotomy between laboratory success and clinical realities

The COVID-19 pandemic has caused significant morbidity and mortality worldwide. The emergence of the Alpha and Delta variants of SARS-CoV-2 has led to a renewed interest in using interferon therapy as a potential treatment option. Interferons are a group of signaling proteins produced by host cells in response to viral infections. They play a critical role in the innate immune response to viral infections by inducing an antiviral state in infected and neighboring cells. Interferon therapy has shown promise as a potential treatment option for COVID-19. In this review paper, we review the current knowledge regarding interferon therapy in the context of the Alpha and Delta variants of SARS-CoV-2 and discuss the challenges that must be overcome to translate laboratory findings into effective clinical treatments.

INHBA promotes tumor growth and induces resistance to PD-L1 blockade by suppressing IFN-γ signaling

Inhibin beta A (INHBA) and its homodimer activin A have pleiotropic effects on modulation of immune responses and tumor progression, but it remains uncertain whether tumors may release activin A to regulate anti-tumor immunity. In this study we investigated the effects and mechanisms of tumor intrinsic INHBA on carcinogenesis, tumor immunity and PD-L1 blockade. Bioinformatic analysis on the TCGA database revealed that INHBA expression levels were elevated in 33 cancer types, including breast cancer (BRCA) and colon adenocarcinoma (COAD). In addition, survival analysis also corroborated that INHBA expression was negatively correlated with the prognosis of many types of cancer patients. We demonstrated that gain or loss function of Inhba did not alter in vitro growth of colorectal cancer CT26 cells, but had striking impact on mouse tumor models including CT26, MC38, B16 and 4T1 models. By using the TIMER 2.0 tool, we figured out that in most cancer types, Inhba expression in tumors was inversely associated with the infiltration of CD4+ T and CD8+ T cells. In CT26 tumor-bearing mice, overexpression of tumor INHBA eliminated the anti-tumor effect of the PD-L1 antibody atezolizumab, whereas INHBA deficiency enhanced the efficacy of atezolizumab. We revealed that tumor INHBA significantly downregulated the interferon-γ (IFN-γ) signaling pathway. Tumor INHBA overexpression led to lower expression of PD-L1 induced by IFN-γ, resulting in poor responsiveness to anti-PD-L1 treatment. On the other hand, decreased secretion of IFN-γ-stimulated chemokines, including C-X-C motif chemokine 9 (CXCL9) and 10 (CXCL10), impaired the infiltration of effector T cells into the tumor microenvironment (TME). Furthermore, the activin A-specific antibody garetosmab improved anti-tumor immunity and its combination with the anti-PD-L1 antibody atezolizumab showed a superior therapeutic effect to monotherapy with garetosmab or atezolizumab. We demonstrate that INHBA and activin A are involved in anti-tumor immunity by inhibiting the IFN-γ signaling pathway, which can be considered as potential targets to improve the responsive rate of PD-1/PD-L1 blockade.

Composite score of PD-1 + CD8 + tumor-infiltrating lymphocytes and CD57 + CD8 + tumor ascites lymphocytes is associated with prognosis and tumor immune microenvironment of patients with advanced high-grade serous ovarian cancer

Objective

The expression of programmed death 1 (PD-1) on CD8+ T cells is associated with their activation and exhaustion, while CD57 serves as a senescence marker. The impact of PD-1+ and CD57+CD8+ T cells on the prognosis of patients with advanced high-grade serous ovarian cancer (HGSOC) remain unclear.

Methods

We assessed the percentages of PD-1+ and CD57+CD8+ T cells in tumor-infiltrating lymphocytes (TILs, n=85) and tumor ascites lymphocytes (TALs, n=87) using flow cytometry. The optimal cutoffs for these markers in TILs and TALs were determined through the log-rank maximization method. Gene expression analysis elucidated the tumor immune microenvironment (TIME, n=36).

Results

Patients with higher PD-1+CD8+ TILs (>87.8%) exhibited longer platinum-free interval (PFI) and overall survival (OS). In contrast, those with elevated CD57+CD8+ TALs (>28.69%) were more likely to experience chemotherapy and had lower complete remission rates, shorter PFI and OS. PD-1+CD8+ TILs are primarily displayed an effector memory state with strong proliferative and secretory capabilities. Approximately 50% of CD57+CD8+ TALs were terminally differentiated, exhibiting significantly impaired proliferation. Based on the proportions of PD-1+CD8+ TILs and CD57+CD8+ TALs, patients were categorized into good, median and poor prognosis groups, with median PFI of 47.78, 27.29 and 11.96 months, respectively (P<0.0001). Median OS for these groups was not reach, 49.23 and 30.92 months, respectively (P<0.0001). Patients with poor prognosis exhibit significantly reduced CD8+ T cell proportion and increased M2 macrophage in the TIME, alongside downregulation of multiple T cell activation-related pathways.

Conclusions

Lower levels of PD-1+CD8+ TILs and higher CD57+CD8+ TALs, assessed prior to treatment, correlated with poor prognosis and suppressive TIME in advanced HGSOC.

Combined PARP14 inhibition and PD-1 blockade promotes cytotoxic T cell quiescence and modulates macrophage polarization in relapsed melanoma

BACKGROUND

Programmed cell death 1 (PD-1) signaling blockade by immune checkpoint inhibitors (ICI) effectively restores immune surveillance to treat melanoma. However, chronic interferon-gamma (IFNγ)-induced immune homeostatic responses in melanoma cells contribute to immune evasion and acquired resistance to ICI. Poly ADP ribosyl polymerase 14 (PARP14), an IFNγ-responsive gene product, partially mediates IFNγ-driven resistance. PARP14 inhibition prolongs PD-1 blockade responses in preclinical models, but fails to achieve full tumor clearance, suggesting the involvement of additional resistance mechanisms.

METHODS

We identified a robust PARP14 catalytic inhibitor gene signature and evaluated its association with patient survival. Using preclinical models and single-cell RNA sequencing, we investigated immune and tumor cell adaptations to PARP14 inhibition combined with PD-1 blockade.

RESULTS

Combining PARP14 inhibition and PD-1 blockade suppressed tumor-associated macrophages while increasing proinflammatory memory macrophages. Moreover, this combination mitigated the terminal exhaustion of cytotoxic T cells by inducing a quiescent state, thereby preserving functionality. Despite the enhanced immune responses, tumor cells developed adaptive resistance by engaging alternative immune evasion pathways.

CONCLUSIONS

Although adaptive resistance mechanisms re-emerge, PARP14 inhibition combined with PD-1 blockade offers a promising strategy to enhance treatment outcomes and overcome ICI resistance in melanoma, as immune cells are primed for further therapeutic interventions that leverage the quiescent state.

Macrophages orchestrate elimination of Shigella from the intestinal epithelial cell niche via TLR-induced IL-12 and IFN-γ

Bacteria of the genus Shigella replicate in intestinal epithelial cells and cause shigellosis, a severe diarrheal disease that resolves spontaneously in most healthy individuals. During shigellosis, neutrophils are abundantly recruited to the gut, and have long been thought to be central to Shigella control and pathogenesis. However, how shigellosis resolves remains poorly understood due to the longstanding lack of a tractable and physiological animal model. Here, using our newly developed Nlrc4 -/- Casp11 -/- mouse model of shigellosis, we unexpectedly find no major role for neutrophils in limiting Shigella or in disease pathogenesis. Instead, we uncover an essential role for macrophages in the host control of Shigella . Macrophages respond to Shigella via TLRs to produce IL-12, which then induces IFN-γ, a cytokine that is essential to control Shigella replication in intestinal epithelial cells. Collectively, our findings reshape our understanding of the innate immune response to Shigella .

The underlying mechanism and therapeutic potential of IFNs in viral-associated cancers

Interferons (IFNs) are a diverse family of cytokines secreted by various cells, including immune cells, fibroblasts, and certain viral-parasitic cells. They are classified into three types and encompass 21 subtypes based on their sources and properties. The regulatory functions of IFNs closely involve cell surface receptors and several signal transduction pathways. Initially investigated for their antiviral properties, IFNs have shown promise in combating cancer-associated viruses, making them a potent therapeutic approach. Most IFNs have been identified for their role in inhibiting cancer; however, they have also demonstrated cancer-promoting effects under specific conditions. These mechanisms primarily rely on immune regulation and cytotoxic effects, significantly impacting cancer progression. Despite widespread use of IFN-based therapies in viral-related cancers, ongoing research aims to develop more effective treatments. This review synthesizes the signal transduction pathways and regulatory capabilities of IFNs, highlighting their connections with viruses, cancers, and emerging clinical treatments.

Cellular and humoral immune responses in cats vaccinated with feline herpesvirus 1 modified live virus vaccine

Feline herpesvirus 1 (FHV-1) is an important pathogen causing infectious rhinotracheitis in felids, mainly infecting the upper respiratory tract and conjunctiva. Multiple vaccines are available to prevent FHV-1 infection, and the antibody levels are always used to evaluate their effectiveness. However, the cellular immunity response following immunization in cats remains unclear. This study investigated the immune responses (humoral and cellular) in cats immunized with the FHV-1 modified live virus vaccine. The results indicated that vaccination significantly reduced clinical signs, and antibody levels, including virus-neutralizing (VN) antibodies and immunoglobulin G (IgG), in the vaccine group were higher than those in the control groups. Additionally, the vaccine significantly increased cytokine secretion, indicating Th1-type cellular immune responses in cats. Moreover, cellular immune-related indicators, such as CD8+ T cells, CD4+ T cells, and interferon-gamma levels, were inversely correlated with clinical signs post-challenge by FHV-1 in vaccinated cats, highlighting its crucial role in protecting cats against FHV-1 infection. In summary, this study demonstrated the importance of cellular immune responses in protecting cats from FHV-1 infection after vaccination.

Resistance mechanisms to immune checkpoint inhibitors: updated insights

The last decade has witnessed unprecedented succusses with the use of immune checkpoint inhibitors in treating cancer. Nevertheless, the proportion of patients who respond favorably to the treatment remained rather modest, partially due to treatment resistance. This has fueled a wave of research into potential mechanisms of resistance to immune checkpoint inhibitors which can be classified into primary resistance or acquired resistance after an initial response. In the current review, we summarize what is known so far about the mechanisms of resistance in terms of being tumor-intrinsic or tumor-extrinsic taking into account the multimodal crosstalk between the tumor, immune system compartment and other host-related factors.

AXL: shapers of tumor progression and immunosuppressive microenvironments

As research progresses, our understanding of the tumor microenvironment (TME) has undergone profound changes. The TME evolves with the developmental stages of cancer and the implementation of therapeutic interventions, transitioning from an immune-promoting to an immunosuppressive microenvironment. Consequently, we focus intently on the significant role of the TME in tumor proliferation, metastasis, and the development of drug resistance. AXL is highly associated with tumor progression; however, previous studies on AXL have been limited to its impact on the biological behavior of cancer cells. An increasing body of research now demonstrates that AXL can influence the function and differentiation of immune cells, mediating immune suppression and thereby fostering tumor growth. A comprehensive analysis to identify and overcome the causes of immunosuppressive microenvironments represents a novel approach to conquering cancer. In this review, we focus on elucidating the role of AXL within the immunosuppressive microenvironments, discussing and analyzing the effects of AXL on tumor cells, T cells, macrophages, natural killer (NK) cells, fibroblasts, and other immune-stromal cells. We aim to clarify the contributions of AXL to the progression and drug resistance of cancer from its functional role in the immune microenvironment.

Uncovering the Heterogeneity of Signaling Pathways in Skin Cutaneous Melanoma: Insights into Prognostic Values and Immune Interactions

Background

Signaling pathways play crucial roles in tumor cells. However, functional heterogeneity of signaling pathways in skin cutaneous melanoma (SKCM) has not been established.

Methods

Based on a recent computational pipeline, pathway activities between SKCM and normal samples were identified.

Results

The results showed that high activities in 12 pathways were associated with poor prognoses, while high activities in 17 pathways were associated with favorable prognoses. Interestingly, elevated metabolic pathway activity was unfavorable, whereas elevated immune activity was favorable for SKCM. Unfavorably elevated metabolic pathways strongly correlated with Wnt/beta-catenin signaling. Conversely, favorable pathways, such as glycosaminoglycan biosynthesis and keratan sulfate, were strongly correlated with anti-tumor pathways. Moreover, the activities of favorable pathways were strongly positively correlated with infiltrating CD8+ T cells, macrophages M1, immune score, and stromal score, all of which were favorable for SKCM.

Conclusion

Taken together, our study provides insights into the characteristics of several pathways in SKCM.

An artificial transcription factor that activates potent interferon-γ expression in human Jurkat T Cells

Interferon (IFN)-γ is a central regulator of cell-mediated immunity in human health and disease, but reduced expression of the target receptors impairs signaling activity and leads to immunotherapy resistance. Although intracellular expression of IFN-γ restores the signaling and downstream functions, we lack the tools to activate the IFNG gene instead of cell surface receptors. This paper introduces the design and characterization of an artificial transcription factor (ATF) protein that recognizes the IFNG gene with six zinc finger domains, which are dovetailed to a VP64 signaling domain that promotes gene transcription and translation. Biological studies with human Jurkat T cells reveal that the ATF amplifies IFNG gene transcription and translation, and also stimulates gene transcription for multiple class I and II HLA alleles and interferon-stimulated genes (ISGs). Biophysical characterization showed the recombinant ATF protein recognizes the human IFNG gene with nanomolar affinity (KD = 5.27 ± 0.3 nM), adopts a protein secondary structure associated with the ββα-fold of zinc finger domains, and is resistant to thermal denaturation. These studies demonstrate that transcriptional targeting of cytokine genes, rather than surface receptors, activates cytokine expression and shows significant potential for directing immune function.

Chemoresistance in Pancreatic Cancer: The Role of Adipose-Derived Mesenchymal Stem Cells and Key Resistance Genes

Drug resistance is a significant challenge in pancreatic ductal adenocarcinoma (PDAC), where stromal elements such as adipose-derived mesenchymal stem cells (ASCs) contribute to a chemoresistant tumor microenvironment (TME). This study explored the effects of oxaliplatin (OXP) and 5-fluorouracil (5-FU) on PDAC cells (Capan-1) and ASCs to investigate the mechanisms of chemoresistance. While OXP and 5-FU reduced Capan-1 viability in a dose- and time-dependent manner, ASCs demonstrated high resistance, maintaining > 90% viability even at cytotoxic doses. Transcriptomic analyses revealed OXP-induced transcriptional reprogramming in ASCs, with over 7000 differentially expressed genes, highlighting the pathways related to DNA damage response, cell cycle regulation, and stress-related signaling. In contrast, 5-FU elicited limited transcriptional changes, affecting only 192 genes. Cytokine proteome profiling revealed that OXP-treated ASCs significantly influenced the tumor microenvironment by promoting immune evasion (via IL-4, GM-CSF, IP-10, and GROα) and driving extracellular matrix remodeling (through EMMPRIN and DPPIV). In contrast, 5-FU induced comparatively weaker effects, primarily limited to hypoxia-related pathways. Although OXP reduced angiogenic factors, it paradoxically activated pro-survival pathways, thereby enhancing ASC-mediated tumor support. These findings underscore ASCs as modulators of chemoresistance via secretome alterations and stress adaptation. Therefore, future strategies should prioritize the precise targeting of tumor cells while also focusing on the development of personalized treatments to achieve durable therapeutic responses in PDAC.

Remodelling of the immune landscape by IFNγ counteracts IFNγ-dependent tumour escape in mouse tumour models

Loss of IFNγ-sensitivity by tumours is thought to be a mechanism enabling evasion, but recent studies suggest that IFNγ-resistant tumours can be sensitised for immunotherapy, yet the underlying mechanism remains unclear. Here, we show that IFNγ receptor-deficient B16-F10 mouse melanoma tumours are controlled as efficiently as WT tumours despite their lower MHC class I expression. Mechanistically, IFNγ receptor deletion in B16-F10 tumours increases IFNγ availability, triggering a remodelling of the immune landscape characterised by inflammatory monocyte infiltration and the generation of 'mono-macs'. This altered myeloid compartment synergises with an increase in antigen-specific CD8+ T cells to promote anti-tumour immunity against IFNγ receptor-deficient tumours, with such an immune crosstalk observed around blood vessels. Importantly, analysis of transcriptomic datasets suggests that similar immune remodelling occurs in human tumours carrying mutations in the IFNγ pathway. Our work thus serves mechanistic insight for the crosstalk between tumour IFNγ resistance and anti-tumour immunity, and implicates this regulation for future cancer therapy.

The anti-tumor effect of the IFNγ/Fas chimera expressed on CT26 tumor cells

Interferon gamma (IFNγ) is well-known for its ability to stimulate immune cells in response to pathogen infections and cancer. To develop an effective cancer therapeutic vaccine, CT26 colon carcinoma cells were genetically modified to express IFNγ either as a secreted form (sIFNγ) or as a membrane-bound form. For the membrane-bound expression, IFNγ was fused with Fas (mbIFNγ/Fas), incorporating the extracellular cysteine-rich domains, transmembrane, and cytoplasmic domains of Fas. The tumor cells expressing sIFNγ and mbIFNγ/Fas showed slower growth rates compared to the mock-transfected cells. Furthermore, the tumorigenicity of the CT26 cells expressing mbIFNγ/Fas was significantly lower than that of cells expressing sIFNγ or the mock control. Remarkably, about 85% of the mice injected with the mbIFNγ/Fas-expressing tumors remained tumor-free for over two months. Mice that rejected mbIFNγ/Fas-expressing tumors developed systemic anti-tumor immunity against CT26 cells, which was characterized by enhanced levels of CD4+ and CD8+ T cells, as well as natural killer (NK) cells. Interestingly, splenocytes activated with the mbIFNγ/Fas-expressing tumors exhibited higher cytotoxicity than those activated with tumor cells expressing sIFNγ. These findings suggest that expressing the mbIFNγ/Fas chimera in tumor cells could be a promising strategy for developing whole tumor cell vaccines or gene therapies for cancer immunotherapy.

Elevated Serum IL-6 as a Negative Prognostic Biomarker in Glioblastoma: Integrating Bioinformatics and Clinical Validation

Background: Glioblastoma multiforme (GBM) is the most lethal type of primary brain tumor, necessitating the discovery of reliable serum prognostic biomarkers. This study aimed to investigate the prognostic value of serum Interleukin-6 (IL-6) in GBM patients. Methods: Bioinformatics analysis via gene set enrichment analysis was conducted on The Cancer Genome Atlas RNA-seq data to explore the pathways enriched in samples with high IL-6 expression. The Tumor IMmune Estimation Resource database was used to analyze the association between IL-6 expression and immune cell infiltration. To validate the role of IL-6 in a clinical setting, a retrospective cohort study was conducted on newly diagnosed GBM patients. Serum IL-6 levels were repeatedly measured at key milestone time points, and their correlation with survival data was analyzed. Results: Bioinformatics analysis revealed that high IL-6 expression is associated with the activation of procancer pathways, that there is a positive correlation between IL-6 expression and immune cell infiltration in GBM. Between March 2021 and September 2023, 36 GBM patients and their serum IL-6 measurements at various time points were included in the clinical data analyses. Elevated serum IL-6 levels at baseline, with a cutoff of 7pg/mL, were identified in 11 patients (30.6%). In the multivariate analyses for overall survival (OS), elevated IL-6 was a significant risk factor (p = 0.048), along with unfavorable surgical resection (p = 0.039) and O6-methylguanine-DNA methyltransferase promotor unmethylation (p = 0.027). The median actuarial OS of the high initial IL-6 group was significantly shorter than that of the low initial IL-6 group (6.4 vs. 19.7 months, p < 0.001). However, IL-6 levels at other time points were not related to patient prognosis. Conclusion: Elevated IL-6 mRNA expression is correlated with the activation of procancer pathways, increased immune cell infiltration, and poor prognosis in GBM patients. In addition, elevated serum IL-6 at baseline is a negative prognostic factor confirmed in a clinical study. Serum IL-6 may be a potential prognostic biomarker enhancing the management of GBM.

Prognostic Features and Potential for Immune Therapy in Metastatic Mismatch Repair-Deficient Colorectal Cancer: A Retrospective Analysis of a Large Consecutive Population-Based Patient Series

BACKGROUND

Immune checkpoint inhibition therapies have provided remarkable results in numerous metastatic cancers, including mismatch repair-deficient (dMMR) colorectal cancer (CRC). To evaluate the potential for PD-1 blockade therapy in a large population-based cohort, we analyzed the tumor microenvironment and reviewed the clinical data and actualized treatment of all dMMR CRCs in Central Finland province between 2000 and 2015.

MATERIAL AND METHODS

Of 1343 CRC patients, 171 dMMR tumors were identified through immunohistochemical screening. Histological tumor parameters were evaluated from hematoxylin- and eosin-stained whole-slide samples. CD3 and CD8 immunohistochemistry were analyzed to calculate T-cell densities in the tumor center and invasive margin, and G-cross function values to estimate cancer cell-T-cell co-localization. Multiplex immunohistochemistry was used to identify CD68+PD-L1+ and CD3+PD-1+ immune cells and PD-L1 expression on tumor cells.

RESULTS

A total of 35 (20%) patients with dMMR tumors were diagnosed as having a metastatic disease. Twelve patients (34%) were fit enough to be offered oncological treatments at the onset of non-curable metastatic disease. High proportions of necrosis and stroma were common in metastatic tumors and were associated with worse survival. Crohn's-like reaction, T-cell proximity score, and CD68+/PD-L1+ on the tumor center and invasive margin were independent prognostic immune factors.

CONCLUSION

As dMMR CRC patients are generally older, with often significant comorbidities, only a limited portion of patients with metastatic dMMR tumors ended up in oncological treatments. Many of the metastatic tumors presented features that may impair response to PD-1 blockade therapy.

SLC2A3 is a Potential Factor for Head and Neck Squamous Cancer Development through Tumor Microenvironment Alteration

INTRODUCTION

Tumor immunity has garnered increasing attention in cancer treatment and progression. However, there is still a challenge in understanding the mechanisms of specific molecules affecting the clinical prognosis and tumor microenvironment (TME).

METHODS

Here, we applied the ESTIMATE algorithm to calculate the immune and stromal scores in 504 HNSC cases from TCGA. Patients were grouped according to the median value of the immune and stromal. Clinicopathological characteristics and differentially expressed genes (DEG) were analyzed. Subsequently, LASSO, COX regression, survival analysis, and clinicopathological characteristics were conducted. Subsequently, SLC2A3 was determined as a predictive factor that high expression of SLC2A3 at the mRNA and protein levels predicted a worse clinical prognosis. GSEA25099 was utilized for external validation of immune infiltration, while tissue PCR, IHC, and Western Blot were used to confirm the expression levels of SLC2A3.

RESULTS

A series of immune-infiltration analyses showed that SLC2A3 expression was negatively correlated with CD8+ T cells, significantly affecting the survival prognosis of HNSC. In the GSEA analysis, the high expression of SLC2A3 was mainly enriched for immune-related biological processes. Meanwhile, high expression of SLC2A3 possessed higher TIDE scores and was also strongly positively correlated with a series of immune checkpoints affecting survival prognosis, thus causing greater susceptibility to immune escape.

CONCLUSION

Conclusively, SLC2A3 is a potential oncogene and factor of HNSC development, notably by an altered state of the immune microenvironment, immune-suppressive regulation, and immune escape.

The crosstalk between senescence, tumor, and immunity: molecular mechanism and therapeutic opportunities

Cellular senescence is characterized by a stable cell cycle arrest and a hypersecretory, proinflammatory phenotype in response to various stress stimuli. Traditionally, this state has been viewed as a tumor-suppressing mechanism that prevents the proliferation of damaged cells while activating the immune response for their clearance. However, senescence is increasingly recognized as a contributing factor to tumor progression. This dual role necessitates a careful evaluation of the beneficial and detrimental aspects of senescence within the tumor microenvironment (TME). Specifically, senescent cells display a unique senescence-associated secretory phenotype that releases a diverse array of soluble factors affecting the TME. Furthermore, the impact of senescence on tumor-immune interaction is complex and often underappreciated. Senescent immune cells create an immunosuppressive TME favoring tumor progression. In contrast, senescent tumor cells could promote a transition from immune evasion to clearance. Given these intricate dynamics, therapies targeting senescence hold promise for advancing antitumor strategies. This review aims to summarize the dual effects of senescence on tumor progression, explore its influence on tumor-immune interactions, and discuss potential therapeutic strategies, alongside challenges and future directions. Understanding how senescence regulates antitumor immunity, along with new therapeutic interventions, is essential for managing tumor cell senescence and remodeling the immune microenvironment.

Interleukin-2-mediated NF-κB-dependent mRNA splicing modulates interferon gamma protein production

Interferon-gamma (IFNγ) is a pleiotropic cytokine produced by natural killer (NK) cells during the early infection response. IFNγ expression is tightly regulated to mount sterilizing immunity while preventing tissue pathology. Several post-transcriptional effectors dampen IFNγ expression through IFNG mRNA degradation. In this study, we identify mRNA splicing as a positive regulator of IFNγ production. While treatment with the combination of IL-12 and IL-2 causes synergistic induction of IFNG mRNA and protein, defying transcription-translation kinetics, we observe that NK cells treated with IL-12 alone transcribe IFNG with introns intact. When NK cells are treated with both IL-2 and IL-12, IFNG transcript is spliced to form mature mRNA with a concomitant increase in IFNγ protein. We find that IL-2-mediated intron splicing occurs independently of nascent transcription but relies upon NF-κB signaling. We propose that while IL-12 transcriptionally induces IFNG mRNA, IL-2 signaling stabilizes IFNG mRNA by splicing detained introns, allowing for rapid IFNγ protein production. This study uncovers a novel role for cytokine-induced splicing in regulating IFNγ through a mechanism potentially applicable to other inflammatory mediators.

Differentiation status determines the effects of IFNγ on the expression of PD-L1 and immunomodulatory genes in melanoma

BACKGROUND

Melanoma cells frequently dedifferentiate in response to inflammation which can increase responses to certain cytokines. Interferon-γ (IFNγ) is an integral part of the anti-tumor immune response and can directly induce both differentiational changes and expression of immunosuppressive proteins in melanoma cells. How the differentiation status of melanoma cells affects IFNγ responses remains unclear.

METHODS

Dedifferentiation of melanoma cells was induced via either siRNA or shRNA mediated MITF knockdown and the cells were subsequently treated with IFNγ. Effects of MITF knockdown and IFNγ treatment on gene expression were evaluated via qPCR and RNA sequencing. A Luminex assay was used to analyze the effects of dedifferentiation and IFNγ treatment on cytokine secretion. Effects on PD-L1 protein expression were analyzed via flow cytometry and western blotting. Inhibition of the JAK kinases, NF-κB and STAT3 with small molecule inhibitors, and siRNA mediated knockdown of STAT1 and IRF1 was applied to investigate the molecular mechanism behind IFNγ induced PD-L1 expression in dedifferentiated melanoma cells. The effects of inhibitor treatments and siRNA mediated knockdowns were evaluated via qPCR and western blotting. Bioinformatic analysis of publicly available RNA sequencing data, consisting of 45 patient derived melanoma cell lines, with or without IFNγ treatment, was conducted to assess the generalizability of the in vitro results.

RESULTS

Dedifferentiation renders 624Mel melanoma cells hypersensitive to IFNγ stimulation in a context-dependent manner, resulting in non-additive upregulation of IFNγ-induced genes, increased PD-L1 protein expression and amplified secretion of CCL2, CXCL10 and IL-10. Furthermore, the intensified PD-L1 protein expression occurs through the JAK-STAT1-IRF1 axis. Lastly, dedifferentiated patient derived melanoma cell lines showed enhanced inflammatory signaling in response to IFNγ compared to differentiated cells, and tended to have higher PD-L1 expression, associated with increased IRF1 expression and activity.

CONCLUSIONS

Together, these findings indicate the existence of a molecular context linking dedifferentiation and IFNγ signaling in melanoma which may lead to immune evasion. Additionally, the variability in PD-L1 expression among MITFlow and MITFhigh cells suggests that high IFNγ-induced PD-L1 expression associates with enhanced inflammatory gene expression. These results imply that modulating melanoma differentiation may help shape IFNγ responsiveness.

A double-edged sword role of IFN-γ-producing iNKT cells in sepsis: Persistent suppression of Treg cell formation in an Nr4a1-dependent manner

Sepsis, a leading cause of mortality in intensive care units worldwide, lacks effective treatments for advanced-stage sepsis. Therefore, understanding the underlying mechanisms of this disease is crucial. This study reveals that invariant natural killer T (iNKT) cells have an opposing role in the progression of sepsis by suppressing regulatory T (Treg) cell differentiation and function. The activation of iNKT cells by α-Galcer enhances interferon (IFN)-γ production. Blocking antibodies or transferring IFN-γ-deficient iNKT cells demonstrates that iNKT cells inhibit Treg differentiation through IFN-γ production. Additionally, iNKT cell-mediated Treg inhibition prevents secondary infection caused by Listeria monocytogenes during the post-septic phase. The transcriptomic analysis of Treg cells further reveals that the suppressive function of Tregs is impaired by iNKT cells. Finally, we demonstrate that iNKT cells inhibit Treg differentiation in an Nr4a1-dependent manner. Our data uncover the dual function of iNKT cells in sepsis progression and provide a potential treatment target for this adverse long-term outcome induced by sepsis.

Role of the TME in immune checkpoint blockade resistance of non-small cell lung cancer

Primary and secondary resistance to immune checkpoint blockade (ICB) reduces its efficacy. The mechanisms underlying immunotherapy resistance are highly complex. In non-small cell lung cancer (NSCLC), these mechanisms are primarily associated with the loss of programmed cell death-ligand 1 (PD-L1) expression, genetic mutations, circular RNA axis and transcription factor regulation, antigen presentation disorders, and dysregulation of signaling pathways. Additionally, alterations in the tumor microenvironment (TME) play a pivotal role in driving immunotherapy resistance. Primary resistance is mainly attributed to TME alterations, including mutations and co-mutations, modulation of T cell infiltration, enrichment of M2 tumor-associated macrophages (M2-TAMs) and mucosal-associated invariant T (MAIT) cells, vascular endothelial growth factor (VEGF), and pulmonary fibrosis. Acquired resistance mainly stems from changes in cellular infiltration patterns leading to "cold" or "hot" tumors, altered interferon (IFN) signaling pathway expression, involvement of extracellular vesicles (EVs), and oxidative stress responses, as well as post-treatment gene mutations and circadian rhythm disruption (CRD). This review presents an overview of various mechanisms underlying resistance to ICB, elucidates the alterations in the TME during primary, adaptive, and acquired resistance, and discusses existing strategies for overcoming ICB resistance.

The Impact of Iron on Cancer-Related Immune Functions in Oncology: Molecular Mechanisms and Clinical Evidence

Iron metabolism plays a dual role in cancer, serving as an essential nutrient for cellular functions and a potential catalyst for tumor growth and immune evasion. Here, we cover the complex interplay between iron levels within the serum or in the microenvironment and cancer therapy, focusing on how iron deficiency and overload can impact immune function, tumor progression, and treatment efficacy. On the one hand, we highlight iron deficiency as a factor of primary immune responses and its adverse effects on anti-cancer immunotherapy efficacy. On the other hand, we also stress the impact of iron overload as an essential factor contributing to tumor growth, creating a suppressive tumor microenvironment that hinders immune checkpoint inhibitor immunotherapy. Overall, we emphasize the necessity of the personalized management of iron levels in oncology patients as a critical element in treatment optimization to achieve favorable outcomes. Based on these considerations, we believe that close and careful monitoring and the tailored balancing of iron supplementation strategies should be the subject of further clinical studies, and routine iron management should be implemented in oncology clinical practice and integrated into cancer therapy protocols.

Selective degradation of multimeric proteins by TRIM21-based molecular glue and PROTAC degraders

Targeted protein degradation (TPD) utilizes molecular glues or proteolysis-targeting chimeras (PROTACs) to eliminate disease-causing proteins by promoting their interaction with E3 ubiquitin ligases. Current TPD approaches are limited by reliance on a small number of constitutively active E3 ubiquitin ligases. Here, we report that (S)-ACE-OH, a metabolite of the antipsychotic drug acepromazine, acts as a molecular glue to induce an interaction between the E3 ubiquitin ligase TRIM21 and the nucleoporin NUP98, leading to the degradation of nuclear pore proteins and disruption of nucleocytoplasmic trafficking. Functionalization of acepromazine into PROTACs enabled selective degradation of multimeric proteins, such as those within biomolecular condensates, while sparing monomeric proteins. This selectivity is consistent with the requirement of substrate-induced clustering for TRIM21 activation. As aberrant protein assemblies cause diseases such as autoimmunity, neurodegeneration, and cancer, our findings highlight the potential of TRIM21-based multimer-selective degraders as a strategy to tackle the direct causes of these diseases.