Migrating into the Tumor: a Roadmap for T Cells

The cGAS‒STING pathway in cancer immunity: mechanisms, challenges, and therapeutic implications

Innate immunity represents the body's first line of defense, effectively countering the invasion of external pathogens. Recent studies have highlighted the crucial role of innate immunity in antitumor defense, beyond its established function in protecting against external pathogen invasion. Enhancing innate immune signaling has emerged as a pivotal strategy in cancer therapy. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling pathway is a key innate immune signal that activates the immune response and exerts antitumor effects; this is primarily attributed to the DNA receptor function of cGAS, which recognizes exogenous DNA to activate downstream STING signaling. This, in turn, promotes the activation of downstream targets such as IRF-3(Interferon Regulatory Factor 3) and NF-κB, leading to the secretion of type I interferons and proinflammatory cytokines, thereby increasing cellular immune activity. The activation of the cGAS-STING pathway may thus play a crucial role in enhancing anticancer immunity. In this paper, we reviewed the role of cGAS-STING signaling in anticancer immunity and its molecular mechanisms. Additionally, we briefly discuss the current applications of the cGAS-STING pathway in cancer immunity, summarize recent developments in STING agonists, and address the challenges facing the use of the cGAS-STING pathway in cancer therapy. Finally, we provide insights into the role of the cGAS‒STING pathway in cancer and propose new directions for cancer immunotherapy.

CAR-T therapy dilemma and innovative design strategies for next generation

Chimeric antigen receptor (CAR)-T-cell therapy has shown remarkable curative effects on hematological tumors, driving the exponential growth in CAR-T-related research. Although CD19-targeting CAR-T-cell therapy has displayed remarkable promise in clinical trials, many obstacles are arising that limit its therapeutic efficacy in tumor immunotherapy. The "dilemma" of CAR-T cell-based tumor therapy includes lethal cytotoxicity, restricted trafficking, limited tumor infiltration, an immunosuppressive microenvironment, immune resistance and limited potency. The solution to CAR-T-cell therapy's dilemma requires interdisciplinary strategies, including synthetic biology-based ON/OFF switch, bioinstructive scaffolds, nanomaterials, oncolytic viruses, CRISPR screening, intestinal microbiota and its metabolites. In this review, we will introduce and summarize these interdisciplinary-based innovative technologies for the next generation CAR-T-cell design and delivery to overcome the key barriers of current CAR-T cells.

Enhancing T-Cell Infiltration and Immunity in Solid Tumors via DNA Nanolinker-Mediated Monocyte Hitchhiking

Cytotoxic CD8+ T cells are one of the most powerful effectors in the antitumor immune response. However, their insufficient tumor infiltration severely limits the clinical success of immunotherapy in solid tumors. In this work, by using amphiphilic aptamer-incorporated DNA tetrahedra (aptTDN) as the intercellular nanolinker, we developed a monocyte-hitchhiked T-cell delivery strategy to actively promote the intratumoral infiltration of effector CD8+ T cells. Our results demonstrated that membrane-anchoring of aptTDN enabled the specific and stable ligation of T cells with Ly6c+ monocytes, without compromising the migratory behavior of monocytes and the antitumor activity of T cells. By leveraging the intrinsic tumor-homing capability of monocytes, the ligated T cells efficiently accumulated within tumor-associated vasculature and then deeply infiltrated the tumor bed. Additionally, the enhanced intratumoral presence of adoptively transferred effector CD8+ T cells facilitated the establishment of an immunosupportive microenvironment, that further recruited endogenous T cells and ultimately bolstered antitumor immunity. Moreover, our monocyte-hitchhiked T-cell tumor infiltration system could significantly improve the efficacy of immune checkpoint blockade therapy. Collectively, by utilizing chemically synthetic nanolinkers to modulate cellular interactions and develop a delivery system of therapeutic cells, our work presents a new paradigm for the advancement of immunotherapy against solid tumors.

Size-specific clonidine-loaded liposomes: Advancing melanoma microenvironment suppression with safety and precision

The immunosuppressive tumor microenvironment (TME) plays a crucial role in the progression and treatment resistance of melanoma. Modulating the TME is thus a key strategy for enhancing therapeutic outcomes. Previousstudies have identified clonidine (CLD), an α2-adrenergic receptor agonist, as a promising agent that enhances T lymphocyte infiltration and reduces myeloid-derived suppressor cells within the TME, thereby promoting antitumor immune responses. In this study, we discovered that CLD reshaped the melanoma immune microenvironment, facilitating T-cell activation and exerting antitumor effects. However, the high doses of CLD required for effective TME modulation pose significant toxicity concerns, limiting its clinical applicability. To address this, we employed the controllable cavitation-on-a-chip (CCC) platform to formulate CLD-loaded liposomes and optimize their size. This approach aimed to enhance the precision and efficacy of drug delivery while reducing systemic side effects. Our results demonstrated that size-specific CLD liposomes, particularly those at 50 nm, significantly improved tumor growth inhibition and immune cell infiltration within the TME. Moreover, these optimized liposomes mitigate adverse effects associated with high-dose CLD treatment. This study indicates the potential of CCC-optimized CLD liposomes as a safer and more effective melanoma therapy, highlighting the critical interplay between liposome size control and therapeutic outcomes in cancer treatment.

D 4 -CHIP REVEALS IMPAIRED T-CELL FUNCTION IN SEPSIS: INSIGHTS FROM PLASMA MICROENVIRONMENT ANALYSIS AND MITOCHONDRIAL-TARGETED THERAPY

ABSTRACT

Background: Sepsis, a systemic inflammation syndrome initiated by infection, poses significant challenges due to its intricate pathophysiology. T cells play a crucial role in combating infections during sepsis. Despite previous observations indicating T-cell dysfunction in sepsis, reliable in vitro detection methods were lacking, and the factors influencing these impairments remained unclear. Methods: We developed a novel method using the D 4 -Chip to assess sepsis T-cell migration function. This microfluidic platform enabled precise analysis of migration function under controlled conditions. Additionally, We explored the impact of the plasma microenvironment on T-cell behavior, along with the redox environment in sepsis, and assessed the potential efficacy of Mitoquinone mesylate (MitoQ), a mitochondrial-targeted drug. Results: Our findings revealed impaired migration function in sepsis T cells compared to healthy controls. Interestingly, sepsis plasma enhanced the migration of healthy T cells, yet incubation with healthy plasma did not fully restore migration impairments in sepsis T cells. Subsequent investigations uncovered a significant increase in NADH/NAD+ levels in sepsis T cells, with healthy T cells exposed to various sepsis plasma conditions also showing elevated NADH/NAD+ levels. Importantly, MitoQ normalized abnormal intracellular NADH/NAD+ levels and enhanced the migration ability of T cells. Conclusions: Short-term incubation with sepsis plasma does not directly inhibit T-cell migration but instead affects T-cell function by disrupting the intracellular redox environment. Improving the intracellular redox environment of sepsis patients contributes to restoring impaired migration and proliferation, with MitoQ demonstrating therapeutic potential.

Targeting the Tumor Microenvironment in EGFR-Mutant Lung Cancer: Opportunities and Challenges

Tyrosine kinase inhibitors (TKIs) have transformed the treatment of epidermal growth factor receptor (EGFR)-mutant non-small cell lung cancer. However, treatment resistance remains a major challenge in clinical practice. The tumor microenvironment (TME) is a complex system composed of tumor cells, immune and non-immune cells, and non-cellular components. Evidence indicates that dynamic changes in TME during TKI treatment are associated with the development of resistance. Research has focused on identifying how each component of the TME interacts with tumors and TKIs to understand therapeutic targets that could address TKI resistance. In this review, we describe how TME components, such as immune cells, fibroblasts, blood vessels, immune checkpoint proteins, and cytokines, interact with EGFR-mutant tumors and how they can promote resistance to TKIs. Furthermore, we discuss potential strategies targeting TME as a novel therapeutic approach.

Tumor-Associated Extracellular Matrix Obstacles for CAR-T Cell Therapy: Approaches to Overcoming

Chimeric antigen receptor (CAR)-T cell therapy yields good results in the treatment of various hematologic malignancies. However, the efficacy of CAR-T cell therapy against solid tumors has proven to be limited, primarily because the tumor-associated extracellular matrix (ECM) creates an intractable barrier for the cytotoxic CAR-T cells that are supposed to kill cancer cells. This review unravels the multifaceted role of the tumor-associated ECM in impeding CAR-T cell infiltration, survival, and functions within solid tumors. We analyze the situations when intratumoral ECM limits the efficacy of CAR-T cell therapy by being a purely physical barrier that complicates lymphocyte penetration/migration and also acts as an immunosuppressive factor that impairs the antitumor activities of CAR-T cells. In addition, we highlight promising approaches such as engineering CAR-T cells with improved capabilities to penetrate and migrate into/through the intratumoral ECM, combination therapies aimed at attenuating the high density and immunosuppressive potential of the intratumoral ECM, and others that enable overcoming ECM-related obstacles. A detailed overview of the data of relevant studies not only helps to better understand the interactions between CAR-T cells and the intratumoral ECM but also outlines potential ways to more effectively use CAR-T cell therapy against solid tumors.

Enhancing immunotherapy efficacy with synergistic low-dose radiation in metastatic melanoma: current insights and prospects

Recent advances in oncology research have highlighted the promising synergy between low-dose radiation therapy (LDRT) and immunotherapies, with growing evidence highlighting the unique benefits of the combination. LDRT has emerged as a potent tool for stimulating the immune system, triggering systemic antitumor effects by remodeling the tumor microenvironment. Notably, LDRT demonstrates remarkable efficacy even in challenging metastatic sites such as the liver (uveal) and brain (cutaneous), particularly in advanced melanoma stages. The increasing interest in utilizing LDRT for secondary metastatic sites of uveal, mucosal, or cutaneous melanomas underscores its potential efficacy in combination with various immunotherapies. This comprehensive review traverses the journey from laboratory research to clinical applications, elucidating LDRT's immunomodulatory role on the tumor immune microenvironment (TIME) and systemic immune responses. We meticulously examine the preclinical evidence and ongoing clinical trials, throwing light on the promising prospects of LDRT as a complementary therapy in melanoma treatment. Furthermore, we explore the challenges associated with LDRT's integration into combination therapies, addressing crucial factors such as optimal dosage, fractionation, treatment frequency, and synergy with other pharmacological agents. Considering its low toxicity profile, LDRT presents a compelling case for application across multiple lesions, augmenting the antitumor immune response in poly-metastatic disease scenarios. The convergence of LDRT with other disciplines holds immense potential for developing novel radiotherapy-combined modalities, paving the way for more effective and personalized treatment strategies in melanoma and beyond. Moreover, the dose-related toxicities of immunotherapies may be reduced by synergistic amplification of antitumor efficacy with LDRT.

Implementation of actin polymerization and depolymerization in a two-dimensional cell migration model and its implications on mammalian cell morphology and velocity

Cell migration, a pivotal process in wound healing, immune response, and even cancer metastasis, manifests through intricate interplay between morphology, speed, and cytoskeletal dynamics. Mathematical modeling emerges as a powerful tool to dissect these complex interactions. This work presents a two-dimensional immersed boundary model for mammalian cell migration, incorporating both filamentous actin (F-actin) and monomeric actin (G-actin) to explicitly capture polymerization and depolymerization. This model builds upon our previous one-dimensional efforts, now enabling us to explore the impact of G-actin on not just cell velocity but also morphology. We compare predictions from both models, revealing that while the one-dimensional model captures core dynamics along the cell's axis, the two-dimensional model excels in portraying cell shape evolution and transverse variations in actin concentration and velocity. Our findings highlight the crucial role of including G-actin in shaping cell morphology. Actin velocity aligned with migration direction elongates the cell, while velocity normal to the membrane promotes spreading. Importantly, the model establishes a link between these microscopic aspects and macroscopic observables like cell shape, offering a deeper understanding of cell migration dynamics. This work not only provides a more comprehensive picture of cell migration but also paves the way for future studies exploring the interplay of actin dynamics, cell morphology, and biophysical parameters in diverse biological contexts.

ImmuNet: a segmentation-free machine learning pipeline for immune landscape phenotyping in tumors by multiplex imaging

Tissue specimens taken from primary tumors or metastases contain important information for diagnosis and treatment of cancer patients. Multiplex imaging allows in situ visualization of heterogeneous cell populations, such as immune cells, in tissue samples. Most image processing pipelines first segment cell boundaries and then measure marker expression to assign cell phenotypes. In dense tissue environments, this segmentation-first approach can be inaccurate due to segmentation errors or overlapping cells. Here, we introduce the machine-learning pipeline "ImmuNet", which identifies positions and phenotypes of cells without segmenting them. ImmuNet is easy to train: human annotators only need to click on an immune cell and score its expression of each marker-drawing a full cell outline is not required. We trained and evaluated ImmuNet on multiplex images from human tonsil, lung cancer, prostate cancer, melanoma, and bladder cancer tissue samples and found it to consistently achieve error rates below 5%-10% across tissue types, cell types, and tissue densities, outperforming a segmentation-based baseline method. Furthermore, we externally validate ImmuNet results by comparing them to flow cytometric cell count measurements from the same tissue. In summary, ImmuNet is an effective, simpler alternative to segmentation-based approaches when only cell positions and phenotypes, but not their shapes, are required for downstream analyses. Thus, ImmuNet helps researchers to analyze cell positions in multiplex tissue images more easily and accurately.

Tumor-infiltrating lymphocytes in melanoma: from prognostic assessment to therapeutic applications

Malignant melanoma, the most aggressive form of skin cancer, is characterized by unpredictable growth patterns, and its mortality rate has remained alarmingly high over recent decades, despite various treatment approaches. One promising strategy for improving outcomes in melanoma patients lies in the early use of biomarkers to predict prognosis. Biomarkers offer a way to gauge patient outlook early in the disease course, facilitating timely, targeted intervention. In recent years, considerable attention has been given to the immune response's role in melanoma, given the tumor's high immunogenicity and potential responsiveness to immunologic treatments. Researchers are focusing on identifying predictive biomarkers by examining both cancer cell biology and immune interactions within the tumor microenvironment (TME). This approach has shed light on tumor-infiltrating lymphocytes (TILs), a type of immune cell found within the tumor. TILs have emerged as a promising area of study for their potential to serve as both a prognostic indicator and therapeutic target in melanoma. The presence of TILs in melanoma tissue can often signal a positive immune response to the cancer, with numerous studies suggesting that TILs may improve patient prognosis. This review delves into the prognostic value of TILs in melanoma, assessing how these immune cells influence patient outcomes. It explores the mechanisms through which TILs interact with melanoma cells and the potential clinical applications of leveraging TILs in treatment strategies. While TILs present a hopeful avenue for prognostication and treatment, there are still challenges. These include understanding the full extent of TIL dynamics within the TME and overcoming limitations in TIL-based therapies. Advancements in TIL characterization methods are also critical to refining TIL-based approaches. By addressing these hurdles, TIL-focused research may pave the way for improved diagnostic and therapeutic options, ultimately offering better outcomes for melanoma patients.

Remolding the tumor microenvironment by bacteria augments adoptive T cell therapy in advanced-stage solid tumors

The intricate tumor microenvironment presents formidable obstacles to the efficacy of adoptive T cell therapy in the management of solid tumors by limiting the infiltration and inducing exhaustion of the transferred T cells. Here, we developed a bacterial-based adjuvant approach that augments the efficacy of adoptive T-cell therapy for solid tumor treatment. Our study reveals that intratumor injection of E. coli MG1655 normalizes tumor vasculatures and reprograms tumor-associated macrophages into M1 phenotype that produce abundant CCL5, together facilitating tumor infiltration of adoptively transferred T cells. The depletion of tumor-associated macrophages or CCL5 neutralization in vivo leads to the significantly decreased solid tumor infiltration of adoptive T cells in the presence of bacteriotherapy. This combinatorial therapy, consisting of E. coli adjuvant and adoptive T-cell therapy, effectively eradicates early-stage melanoma and inhibits the progression of pancreatic tumors. Notably, this dual strategy also strengthened the distal tumor control capabilities of adoptive T-cell therapy through the induction of in situ tumor vaccination. This dual therapeutic approach involving bacterial therapy targeting the interior of solid tumors and adoptive T-cell therapy attacking the tumor periphery exhibits potent therapeutic efficacy in achieving the eradication of advanced-stage tumors, including melanoma and hepatocellular carcinoma, by converging attacks from both inside and outside the tumor tissues.

ADAM10 modulates the efficacy of T-cell-mediated therapy in solid tumors

T-cell-mediated therapeutic strategies are the most potent effectors of cancer immunotherapy. However, an essential barrier to this therapy in solid tumors is disrupting the anti-cancer immune response, cancer-immunity cycle, T-cell priming, trafficking and T-cell cytotoxic capacity. Thus, reinforcing the anti-cancer immune response is needed to improve the effectiveness of T-cell-mediated therapy. Tumor-associated protease ADAM10, endothelial cells (ECs) and cytotoxic CD8+ T cells engage in complex communication via adhesion, transmigration and chemotactic mechanisms to facilitate an anti-cancer immune response. The precise impact of ADAM10 on the intricate mechanisms underlying these interactions remains unclear. This paper broadly explores how ADAM10, through different routes, influences the efficacy of T-cell-mediated therapy. ADAM10 cleaves CD8+ T-cell-targeting genes and impacts their expression and specificity. In addition, ADAM10 mediates the interactions of adhesion molecules with T cells and influences CD8+ T-cell activity and trafficking. Thus, understanding the role of ADAM10 in these events may lead to innovative strategies for advancing T-cell-mediated therapies.

Tumor-targeting bacteria as immune stimulants - the future of cancer immunotherapy?

Cancer immunotherapies have been widely hailed as a breakthrough for cancer treatment in the last decade, epitomized by the unprecedented results observed with checkpoint blockade. Even so, only a minority of patients currently achieve durable remissions. In general, responsive patients appear to have either a high number of tumor neoantigens, a preexisting immune cell infiltrate in the tumor microenvironment, or an 'immune-active' transcriptional profile, determined in part by the presence of a type I interferon gene signature. These observations suggest that the therapeutic efficacy of immunotherapy can be enhanced through strategies that release tumor neoantigens and/or produce a pro-inflammatory tumor microenvironment. In principle, exogenous tumor-targeting bacteria offer a unique solution for improving responsiveness to immunotherapy. This review discusses how tumor-selective bacterial infection can modulate the immunological microenvironment of the tumor and the potential for combination with cancer immunotherapy strategies to further increase therapeutic efficacy. In addition, we provide a perspective on the clinical translation of replicating bacterial therapies, with a focus on the challenges that must be resolved to ensure a successful outcome.

Targeted nanomedicine for reprogramming the tumor innate immune system: From bench to bedside

Tumor-associated innate immune cells such as tumor-associated macrophages, neutrophils, dendritic cells play a crucial role in tumor progression, angiogenesis and metastasis. These cells also control the efficacy of chemotherapy and immunotherapy by inducing drug resistance and immunosuppression, leading to therapeutic failures. Therefore, targeting the tumor-associated innate immune cells has gained high attention for the development of effective cancer therapy. Nanomedicine based strategies to target these cells are highly relevant and can be used to reprogram these cells. In this review, we discuss the fundamental roles of the tumor-associated innate immune cells in the tumor microenvironment and different strategies to modulate them. Then, nanomedicine-based strategies to target different tumor innate immune cells are explained in detail. While the clinical development of the targeted nanomedicine remains a great challenge in practice, we have provided our perspectives on various factors such as pharmaceutical aspects, preclinical testing and biological aspects which are crucial to consider before translating these targeting strategies to clinics.

A microphysiological assay for studying T-cell chemotaxis, trafficking and tumor killing

Tumors in patients non-responsive to immunotherapy harbor a series of barriers that impede the efficacy of effector T-cells. Consequently, therapeutically modulating the chemotaxis machinery to enable effector T cell infiltration and function in the tumor could result in more successful therapeutic outcomes. Complexin-vitromodels allow re-creation ofin-vivotumor complexities in anin-vitrosetting, allowing improved translatability to patient biology at the laboratory scale. We identified a gap in available industrial scale microphysiological (MPS) assays for faster validation of targets and strategies that enable T-cell chemotaxis and effector function within tumor microenvironments. Using a commercially available, 96-chip 2-lane microfluidic assay system, we present a novel, scalable, complexin vitroMPS assay to study 3D T-cell chemotaxis and function within native, extracellular matrix (ECM)-rich multicellular tumor environments. Activated or naïve CD3+ T-cells stained with far-red nuclear stain responded to the chemokine gradients generated within the matrigel-collagen ECM by migrating into the microfluidic channel (∼5 mm horizontal window), in a concentration- and cell type-dependent manner. Furthermore, we observed and tracked chemotaxis and cancer cell killing function of antigen-specific CD4.CD8. chimeric antigen receptor (CAR)-T cells that responded to CXCR3 agonist gradient built through the expansive 5 mm of cancer cell colony containing stroma. The 2-lane assay system yielded useful information regarding donor and dose-dependent differences in CAR-T cell chemotaxis and tumor killing. The scalable assay system allows a granular window into immune cell migration and function in tissue spaces beyond endothelium, addressing a missing gap in studying tissue-specific immune cell chemotaxis and function to bring forward advancements in cancer immunotherapy.

Cold and hot tumors: from molecular mechanisms to targeted therapy

Immunotherapy has made significant strides in cancer treatment, particularly through immune checkpoint blockade (ICB), which has shown notable clinical benefits across various tumor types. Despite the transformative impact of ICB treatment in cancer therapy, only a minority of patients exhibit a positive response to it. In patients with solid tumors, those who respond well to ICB treatment typically demonstrate an active immune profile referred to as the "hot" (immune-inflamed) phenotype. On the other hand, non-responsive patients may exhibit a distinct "cold" (immune-desert) phenotype, differing from the features of "hot" tumors. Additionally, there is a more nuanced "excluded" immune phenotype, positioned between the "cold" and "hot" categories, known as the immune "excluded" type. Effective differentiation between "cold" and "hot" tumors, and understanding tumor intrinsic factors, immune characteristics, TME, and external factors are critical for predicting tumor response and treatment results. It is widely accepted that ICB therapy exerts a more profound effect on "hot" tumors, with limited efficacy against "cold" or "altered" tumors, necessitating combinations with other therapeutic modalities to enhance immune cell infiltration into tumor tissue and convert "cold" or "altered" tumors into "hot" ones. Therefore, aligning with the traits of "cold" and "hot" tumors, this review systematically delineates the respective immune characteristics, influencing factors, and extensively discusses varied treatment approaches and drug targets based on "cold" and "hot" tumors to assess clinical efficacy.

Tumor draining lymph nodes connected to cold triple-negative breast cancers are characterized by Th2-associated microenvironment

Tumor draining lymph nodes (TDLN) represent a key component of the tumor-immunity cycle. There are few studies describing how TDLNs impact lymphocyte infiltration into tumors. Here we directly compare tumor-free TDLNs draining "cold" and "hot" human triple negative breast cancers (TDLNCold and TDLNHot). Using machine-learning-based self-correlation analysis of immune gene expression, we find unbalanced intranodal regulations within TDLNCold. Two gene pairs (TBX21/GATA3-CXCR1) with opposite correlations suggest preferential priming of T helper 2 (Th2) cells by mature dendritic cells (DC) within TDLNCold. This is validated by multiplex immunofluorescent staining, identifying more mature-DC-Th2 spatial clusters within TDLNCold versus TDLNHot. Associated with this Th2 priming preference, more IL4 producing mast cells (MC) are found within sinus regions of TDLNCold. Downstream, Th2-associated fibrotic TME is found in paired cold tumors with increased Th2/T-helper-1-cell (Th1) ratio, upregulated fibrosis growth factors, and stromal enrichment of cancer associated fibroblasts. These findings are further confirmed in a validation cohort and public genomic data. Our results reveal a potential role of IL4+ MCs within TDLNs, associated with Th2 polarization and reduced immune infiltration into tumors.

RILPL2 as a potential biomarker for predicting enhanced T cell infiltration in non-small cell lung cancer

Our previous bioinformatics analysis has revealed that Rab-interacting lysosomal protein-like 2 (RILPL2) is associated with tumor immune microenvironment in non-small cell lung cancer (NSCLC). In our study, we collected 140 patients with primary NSCLC to verify the RILPL2 expression and its prognostic value, the relationship between RILPL2 expression and CD4+, CD8+T cell infiltration. A total of 140 patients who had been diagnosed with primary NSCLC (including 66 lung adenocarcinomas and 74 lung squamous cell carcinomas) were enrolled in our study. Immunohistochemical (IHC) staining was performed to analyze the expression of RILPL2, CD4, and CD8 in these patients. Compared with peri-cancer tissues, the RILPL2 expression in NSCLC tissues was significantly lower (P < 0.0001). RILPL2 expression was significantly related to clinical stage (P = 0.019), and low RILPL2 expression indicated higher stage. Low RILPL2 expression predicted worse overall survival (OS) in NSCLC patients (P = 0.017). Correlational analyses revealed that RILPL2 expression was significantly positively correlated with CD4+T cell infiltration in NSCLC (R = 0.294, P < 0.001), LUAD subgroup (R = 0.256, P = 0.038), and LUSC subgroup (R = 0.333, P = 0.004); RILPL2 expression was also significantly positively correlated with CD8+ T cell infiltration in NSCLC (R = 0.263, P = 0.002), LUAD subgroup (R = 0.280, P = 0.023), and LUSC subgroup (R = 0.250, P = 0.031). In conclusion, RILPL2 expression was downregulated in NSCLC; low RILPL2 expression was significantly related to higher stage and worse prognosis; RILPL2 expression was significantly positively correlated with CD4+, CD8+T cell infiltration.

Advances in Immune Checkpoint Therapy in Hepatocellular Carcinoma

The incidence and lethality of hepatocellular carcinoma (HCC) are increasing annually, and traditional treatments have been proven to be ineffective for patients with advanced stages of the disease. In recent years, immune checkpoint therapy has rapidly evolved, demonstrating promising results across a wide range of cancers and offering new hope for cancer treatment. However, the efficacy of immune checkpoint therapy in HCC varies greatly among individuals, with only a small proportion of HCC patients responding positively. A major cause of immune resistance and poor efficacy in HCC patients is immune evasion, which is often due to insufficient infiltration of immune cells. Understanding the mechanisms underlying immune evasion is crucial for enhancing the efficacy of immune therapies. In this review, we aim to summarize the mechanisms of immune evasion observed during immune checkpoint therapy and discuss future directions for this therapeutic approach. Our goal is to provide insights that could help overcome immune evasion, thereby improving the efficacy of immune therapies and extending patient survival time.

A novel oral TLR7 agonist orchestrates immune response and synergizes with PD-L1 blockade via type I IFN pathway in lung cancer

Despite the groundbreaking impact of immune checkpoint blockade (ICB), response rates in non-small cell lung cancer remain modest, particularly in immune-excluded or immune-desert microenvironments. Toll-like receptor 7 (TLR7) emerges as a latent target bridging innate and adaptive immunity, offering a promising avenue for combination therapies to augment ICB efficacy. Here, we explored the anti-tumor activity of the novel oral TLR7 agonist TQ-A3334 and its potential to enhance anti-programmed death ligand 1 (PD-L1) therapy through a combination strategy in a syngeneic murine lung cancer model. Oral administration of TQ-A3334 significantly alleviated tumor burden in C57BL/6J mice, modulated by type I interferon (IFN), and exhibited low toxicity. This therapy elicited activation of both innate and adaptive immune cells in tumor tissue, particularly increasing the abundance of CD8+ TILs through type I IFN pathway and subsequent CXCL10 expression. In vitro examinations validated that IFN-α-stimulated tumor cells exhibited increased secretion of CXCL10, conducive to the promoted trafficking of CD8+ T cells. Furthermore, combining TQ-A3334 with anti-PD-L1 treatment exceeded tumor control, with a further increase in CD8+ TIL frequency compared to monotherapy. These findings suggest that TQ-A3334 can mobilize innate immunity and promote T cell recruitment into the tumor microenvironment; a combination of TQ-A3334 and anti-PD-L1 antibodies can intensify the sensitivity of tumors to anti-PD-L1 therapy, which demonstrates significant potential for treating poorly immune-infiltrated lung cancer.

Tissue- and Temporal-Dependent Dynamics of Myeloablation in Response to Gemcitabine Chemotherapy

For triple-negative breast cancer (TNBC), the most aggressive subset of breast cancer, immune cell infiltrates have prognostic implications. The presence of myeloid-derived suppressor cells supports tumor progression, while tumor-infiltrating lymphocytes (TILs) correlate with improved survival and responsiveness to immunotherapy. Manipulating the abundance of these populations may enhance tumor immunity. Gemcitabine (GEM), a clinically employed chemotherapeutic, is reported to be systemically myeloablative, and thus it is a potentially useful adjunct therapy for promoting anti-tumor immunity. However, knowledge about the immunological effects of GEM intratumorally is limited. Thus, we directly compared the impact of systemic GEM on immune cell presence and functionality in the tumor microenvironment (TME) to its effects in the periphery. We found that GEM is not myeloablative in the TME; rather, we observed sustained, significant reductions in TILs and dendritic cells-crucial components in initiating an adaptive immune response. We also performed bulk-RNA sequencing to identify immunological alterations transcriptionally induced by GEM. While we found evidence of upregulation in the interferon-gamma (IFN-γ) response pathway, we determined that GEM-mediated growth control is not dependent on IFN-γ. Overall, our findings yield new insights into the tissue- and temporal-dependent immune ablative effects of GEM, contrasting the paradigm that this therapy is specifically myeloablative.

Next-generation cancer vaccines and emerging immunotherapy combinations

Therapeutic cancer vaccines have been a subject of research for several decades as potential new weapons to tackle malignancies. Their goal is to induce a long-lasting and efficient antitumour-directed immune response, capable of mediating tumour regression, preventing tumour progression, and eradicating minimal residual disease, while avoiding major adverse effects. Development of new vaccine technologies and antigen prediction methods has led to significant improvements in cancer vaccine efficacy. However, for their successful clinical application, certain obstacles still need to be overcome, especially tumour-mediated immunosuppression and escape mechanisms. In this review, we introduce therapeutic cancer vaccines and subsequently discuss combination approaches of next-generation cancer vaccines and existing immunotherapies, particularly immune checkpoint inhibitors (ICIs) and adoptive cell transfer/cell-based immunotherapies.

Deconstructing Intratumoral Heterogeneity through Multiomic and Multiscale Analysis of Serial Sections

Tumors may contain billions of cells, including distinct malignant clones and nonmalignant cell types. Clarifying the evolutionary histories, prevalence, and defining molecular features of these cells is essential for improving clinical outcomes, since intratumoral heterogeneity provides fuel for acquired resistance to targeted therapies. Here we present a statistically motivated strategy for deconstructing intratumoral heterogeneity through multiomic and multiscale analysis of serial tumor sections (MOMA). By combining deep sampling of IDH-mutant astrocytomas with integrative analysis of single-nucleotide variants, copy-number variants, and gene expression, we reconstruct and validate the phylogenies, spatial distributions, and transcriptional profiles of distinct malignant clones. By genotyping nuclei analyzed by single-nucleus RNA-seq for truncal mutations, we further show that commonly used algorithms for identifying cancer cells from single-cell transcriptomes may be inaccurate. We also demonstrate that correlating gene expression with tumor purity in bulk samples can reveal optimal markers of malignant cells and use this approach to identify a core set of genes that are consistently expressed by astrocytoma truncal clones, including AKR1C3, whose expression is associated with poor outcomes in several types of cancer. In summary, MOMA provides a robust and flexible strategy for precisely deconstructing intratumoral heterogeneity and clarifying the core molecular properties of distinct cellular populations in solid tumors.

Anti-VEGFR2-Interferon α Promotes the Infiltration of CD8+ T Cells in Colorectal Cancer by Upregulating the Expression of CCL5

SUMMARY

Immunocytokines are a promising immunotherapeutic approach in cancer therapy. Anti-VEGFR2-interferon α (IFNα) suppressed colorectal cancer (CRC) growth and enhanced CD8 + T-cell infiltration in the tumor microenvironment, exhibiting great clinical translational potential. However, the mechanism of how the anti-VEGFR2-IFNα recruits T cells has not been elucidated. Here, we demonstrated that anti-VEGFR2-IFNα suppressed CRC metastasis and enhanced CD8 + T-cell infiltration. RNA sequencing revealed a transcriptional activation of CCL5 in metastatic CRC cells, which was correlated with T-cell infiltration. IFNα but not anti-VEGFR2 could further upregulate CCL5 in tumors. In immunocompetent mice, both IFNα and anti-VEGFR2-IFNα increased the subset of tumor-infiltrating CD8 + T cells through upregulation of CCL5. Knocking down CCL5 in tumor cells attenuated the infiltration of CD8 + T cells and dampened the antitumor efficacy of anti-VEGFR2-IFNα treatment. We, therefore, propose upregulation of CCL5 is a key to enhance infiltration of CD8 + T cells in metastatic CRC with IFNα and IFNα-based immunocytokine treatments. These findings may help the development of IFNα related immune cytokines for the treatment of less infiltrated tumors.

MDM2/MDMX inhibition by Sulanemadlin synergizes with anti-Programmed Death 1 immunotherapy in wild-type p53 tumors

Immunotherapy has revolutionized cancer treatment but its efficacy depends on a robust immune response in the tumor. Silencing of the tumor suppressor p53 is common in tumors and can affect the recruitment and activation of different immune cells, leading to immune evasion and poor therapy response. We found that the p53 activating stapled peptide MDM2/MDMX inhibitor Sulanemadlin (ALRN-6924) inhibited p53 wild-type cancer cell growth in vitro and in vivo. In mice carrying p53 wild-type CT26.WT tumors, monotherapy with the PD-1 inhibitor DX400 or Sulanemadlin delayed tumor doubling time by 50% and 37%, respectively, while combination therapy decreased tumor doubling time by 93% leading to an increased median survival time. Sulanemadlin treatment led to increased immunogenicity and combination treatment with PD-1 inhibition resulted in an increased tumor infiltration of lymphocytes. This combination treatment strategy could potentially turn partial responders into responders of immunotherapy, expanding the patient target group for PD-1-targeting immunotherapy.

Prognostic and clinicopathological significance of systemic immune-inflammation index in upper tract urothelial carcinoma: a meta-analysis of 3911 patients

Background

Systemic immune-inflammation index (SII), a novel prognostic indicator, is being more commonly utilized in different types of cancer. This research project involved combining information from previously published studies to examine how pre-treatment SII can predict outcomes in individuals with upper tract urothelial carcinoma (UTUC). Further examination of the correlation between SII and clinical and pathological features in UTUC.

Methods

We thoroughly chose pertinent articles from various databases including PubMed, Embase, Cochrane Library, Web of Science, Chinese National Knowledge Infrastructure (CNKI), WanFang database, and Chinese Scientific Journal Database (VIP) until March 10, 2022.The data collected was analyzed using Stata 17.0 software (Stat Corp, College Station, TX). Subsequently, the impact of SII on the survival outcomes of UTUC patients was evaluated by combining HRs with 95% confidence intervals.

Results

Six included studies were finally confirmed, including 3911 UTUC patients in seven cohorts. The results showed that high SII before treatment predicted poor overall survival (HR =1.87, 95%CI 1.20-2.92, p=0.005), cancer specific survival (HR=2.70, 95%CI 1.47-4.96, P=0.001), and recurrence-free survival (HR =1.52, 95%CI 1.12-2.07, P=0.007). And the elevated SII may be related to LVI (present vs. absent) (OR=0.83, 95% CI=0.71-0.97, p=0.018), pT stage (pT ≥3 vs. < 3) (OR=1.82, 95% CI=1.21-2.72, p=0.004), and pN stage (N+ vs. N0) (OR=3.27, 95% CI=1.60-6.71, p=0.001).

Conclusion

A comprehensive analysis of all included articles in this study showed that higher pretreatment SII was related to poorer survival outcomes and adverse pathological features independently.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022316333.

Migration of human T cells can be differentially directed by electric fields depending on the extracellular microenvironment

T cell migration plays an essential role in the immune response and T cell-based therapies. It can be modulated by chemical and physical cues such as electric fields (EFs). The mechanisms underlying electrotaxis (cell migration manipulated by EFs) are not fully understood and systematic studies with immune cells are rare. In this in vitro study, we show that direct current EFs with strengths of physiologically occurring EFs (25-200 mV/mm) can guide the migration of primary human CD4+ and CD8+ T cells on 2D substrates toward the anode and in a 3D environment differentially (CD4+ T cells show cathodal and CD8+ T cells show anodal electrotaxis). Overall, we find that EFs present a potent stimulus to direct T cell migration in different microenvironments in a cell-type-, substrate-, and voltage-dependent manner, while not significantly influencing T cell differentiation or viability.

Low-dose radiotherapy synergizes with iRGD-antiCD3-modified T cells by facilitating T cell infiltration

BACKGROUND AND PURPOSE

Poor penetration of transferred T cells represents a critical factor impeding the development of adoptive cell therapy in solid tumors. We demonstrated that iRGD-antiCD3 modification promoted both T cell infiltration and activation in our previous work. Interest in low-dose radiotherapy has recently been renewed due to its immuno-stimulatory effects including T cell recruitment. This study aims to explore the synergistic effects between low-dose radiotherapy and iRGD-antiCD3-modified T cells.

MATERIALS AND METHODS

Flow cytometry was performed to assess the expression of iRGD receptors and chemokines. T cell infiltration was evaluated by immunohistofluorescence and in vivo real-time fluorescence imaging and antitumor effects were investigated by in vivo bioluminescence imaging in the gastric cancer peritoneal metastasis mouse model.

RESULTS

We found that 2 Gy irradiation upregulated the expression of all three iRGD receptors and T-cell chemokines. The addition of 2 Gy low-dose irradiation boosted the accumulation and penetration of iRGD-antiCD3-modified T cells in peritoneal tumor nodules. Combining 2 Gy low-dose irradiation with iRGD-antiCD3-modified T cells significantly inhibited tumor growth and prolonged survival in the peritoneal metastasis mouse model with a favorable safety profile.

CONCLUSION

Altogether, we demonstrated that low-dose radiotherapy could improve the antitumor potency of iRGD-antiCD3-modified T cells by promoting T cell infiltration, providing a rationale for exploring low-dose radiotherapy in combination of other adoptive T cell therapies in solid tumors.

Identification of prognostic m6A modification patterns and score system in melanoma patients

N6-methyladenosine (m6A) is the most common modification on RNAs and LncRNAs. It plays an important role in cancer stem cell differentiation, T cell differentiation, and immune homeostasis. In this study, we explored the potential roles of m6A modification of RNA in melanoma and investigated the immune cell infiltration in tumor microenvironment in diverse m6Aclusters and different m6Ascore groups. A consensus clustering algorithm determined m6A modification patterns based on 14 m6A regulators, and further explored the biological functions and the connection with TME. An m6A-related gene signature (m6Ascore) was constructed based on m6A-related genes using principal component analysis. Three m6A modification patterns were identified based on 14 m6A regulators, named as m6Aclusters A-C. The prognosis of m6Acluster A was more favorable than m6Aclusters B and C, and it was more closely associated with immune regulation. To quantify the m6A modification patterns of individual tumor, an m6Ascore was constructed, and patients were classified into high and low m6Ascore groups. The low m6Ascore group, which had a favorable prognosis, was more relevant to immunology. The expression of PD-L1 was higher and the immunophenoscore (IPS) revealed stronger response to immunotherapy in the low m6Ascore group. This study identified 3 m6A modification patterns with different immune characteristics and constructed an m6Ascore system to predict prognosis and immunogenicity of patients, which is conducive to clinical prognosis judgment and individual treatment.

Microphysiological systems as models for immunologically 'cold' tumors

The tumor microenvironment (TME) is a diverse milieu of cells including cancerous and non-cancerous cells such as fibroblasts, pericytes, endothelial cells and immune cells. The intricate cellular interactions within the TME hold a central role in shaping the dynamics of cancer progression, influencing pivotal aspects such as tumor initiation, growth, invasion, response to therapeutic interventions, and the emergence of drug resistance. In immunologically 'cold' tumors, the TME is marked by a scarcity of infiltrating immune cells, limited antigen presentation in the absence of potent immune-stimulating signals, and an abundance of immunosuppressive factors. While strategies targeting the TME as a therapeutic avenue in 'cold' tumors have emerged, there is a pressing need for novel approaches that faithfully replicate the complex cellular and non-cellular interactions in order to develop targeted therapies that can effectively stimulate immune responses and improve therapeutic outcomes in patients. Microfluidic devices offer distinct advantages over traditional in vitro 3D co-culture models and in vivo animal models, as they better recapitulate key characteristics of the TME and allow for precise, controlled insights into the dynamic interplay between various immune, stromal and cancerous cell types at any timepoint. This review aims to underscore the pivotal role of microfluidic systems in advancing our understanding of the TME and presents current microfluidic model systems that aim to dissect tumor-stromal, tumor-immune and immune-stromal cellular interactions in various 'cold' tumors. Understanding the intricacies of the TME in 'cold' tumors is crucial for devising effective targeted therapies to reinvigorate immune responses and overcome the challenges of current immunotherapy approaches.

Deconstructing intratumoral heterogeneity through multiomic and multiscale analysis of serial sections

Tumors may contain billions of cells including distinct malignant clones and nonmalignant cell types. Clarifying the evolutionary histories, prevalence, and defining molecular features of these cells is essential for improving clinical outcomes, since intratumoral heterogeneity provides fuel for acquired resistance to targeted therapies. Here we present a statistically motivated strategy for deconstructing intratumoral heterogeneity through multiomic and multiscale analysis of serial tumor sections (MOMA). By combining deep sampling of IDH-mutant astrocytomas with integrative analysis of single-nucleotide variants, copy-number variants, and gene expression, we reconstruct and validate the phylogenies, spatial distributions, and transcriptional profiles of distinct malignant clones. By genotyping nuclei analyzed by single-nucleus RNA-seq for truncal mutations, we further show that commonly used algorithms for identifying cancer cells from single-cell transcriptomes may be inaccurate. We also demonstrate that correlating gene expression with tumor purity in bulk samples can reveal optimal markers of malignant cells and use this approach to identify a core set of genes that is consistently expressed by astrocytoma truncal clones, including AKR1C3, whose expression is associated with poor outcomes in several types of cancer. In summary, MOMA provides a robust and flexible strategy for precisely deconstructing intratumoral heterogeneity and clarifying the core molecular properties of distinct cellular populations in solid tumors.

Intratumoral Delivery of Interleukin 9 via Oncolytic Vaccinia Virus Elicits Potent Antitumor Effects in Tumor Models

The success of cancer immunotherapy is largely associated with immunologically hot tumors. Approaches that promote the infiltration of immune cells into tumor beds are urgently needed to transform cold tumors into hot tumors. Oncolytic viruses can transform the tumor microenvironment (TME), resulting in immunologically hot tumors. Cytokines are good candidates for arming oncolytic viruses to enhance their function in this transformation. Here, we used the oncolytic vaccinia virus (oVV) to deliver interleukin-9 (IL-9) into the tumor bed and explored its antitumor effects in colon and lung tumor models. Our data show that IL-9 prolongs viral persistence, which is probably mediated by the up-regulation of IL-10. The vvDD-IL-9 treatment elevated the expression of Th1 chemokines and antitumor factors such as IFN-γ, granzyme B, and perforin. IL-9 expression increased the percentages of CD4+ and CD8+ T cells in the TME and decreased the percentage of oVV-induced immune suppressive myeloid-derived suppressor cells (MDSC), leading to potent antitumor effects compared with parental virus treatment. The vvDD-IL-9 treatment also increased the percentage of regulatory T cells (Tregs) in the TME and elevated the expression of immune checkpoint molecules such as PD-1, PD-L1, and CTLA-4, but not GITR. The combination therapy of vvDD-IL-9 and the anti-CTLA-4 antibody, but not the anti-GITR antibody, induced systemic tumor-specific antitumor immunity and significantly extended the overall survival of mice, indicating a potential translation of the IL-9-expressing oncolytic virus into a clinical trial to enhance the antitumor effects elicited by an immune checkpoint blockade for cancer immunotherapy.

Liquid biopsy approach to monitor the efficacy and response to CAR-T cell therapy

BACKGROUND

Chimeric antigen receptor (CAR)-T cells are approved for use in the treatment of hematological malignancies. Axicabtagene ciloleucel (YESCARTA) and brexucabtagene autoleucel (TECARTUS) genetically modified autologous T cells expressing an anti-CD19 scFv based on the FMC63 clone have shown impressive response rates for the treatment of CD19+B cell malignancies, but there remain challenges in monitoring long-term persistence as well as the functional characterization of low-level persisting CAR-T cells in patients. Furthermore, due to CD19-negative driven relapse, having the capability to monitor patients with simultaneous detection of the B cell malignancy and persisting CAR-T cells in patient peripheral blood is important for ensuring timely treatment optionality and understanding relapse.

METHODS

This study demonstrates the development and technical validation of a comprehensive liquid biopsy, high-definition single cell assay (HDSCA)-HemeCAR for (1) KTE-X19 CAR-T cell identification and analysis and (2) simultaneously monitoring the CD19-epitope landscape on neoplastic B cells in cryopreserved or fresh peripheral blood. Proprietary anti-CD19 CAR reagents, healthy donor transduced CAR-T cells, and patient samples consisting of malignant B cell fractions from manufacturing were used for assay development.

RESULTS

The CAR-T assay showed an approximate limit of detection at 1 cell in 3 million with a sensitivity of 91%. Genomic analysis was additionally used to confirm the presence of the CAR transgene. This study additionally reports the successful completion of two B cell assays with multiple CD19 variants (FMC63 and LE-CD19) and a unique fourth channel biomarker (CD20 or CD22). In patient samples, we observed that CD19 isoforms were highly heterogeneous both intrapatient and interpatient.

CONCLUSIONS

With the simultaneous detection of the CAR-T cells and the B cell malignancy in patient peripheral blood, the HDSCA-HemeCAR workflow may be considered for risk monitoring and patient management.

Tumor Copy Number Alteration Burden as a Predictor for Resistance to Immune Checkpoint Blockade across Different Cancer Types

Immune checkpoint blockade (ICB) benefits only a subset of advanced cancer patients, and predictive biomarkers for immunotherapy response are needed. Recently, copy number alteration (CNA) burden has been proposed to predict ICB resistance. We assessed this finding using the publicly accessible data for 1661 ICB-treated patients whose tumors were profiled by MSK-IMPACT, an approved targeted assay in clinical care. We tested the hypothesis that the continuous increase in CNA burden is associated with poor overall survival following ICB. In addition, we hypothesized that the combinatorial biomarkers of tumor mutational burden (TMB) and CNA burden would better stratify patients for immune status and ICB response. Of the 1661 cases, 79% (n = 1307) were treated with anti PD-1/PD-L1 and the remaining 21% (n = 354) with anti CTLA-4 or the combination of both. In a multivariate analysis, increase in CNA burden was associated with poor overall survival [HR = 1.52, 95% CI (1.01-2.30), p = 0.04]. The combination of biomarkers TMB and CNA burden stratified patients into four clinically distinct subsets among which "LowTMB/HighCNA" showed the worst survival (p < 0.0001). The four patient subsets had unique CNA profiles and enriched pathways, which could predict transcriptional and phenotypic effects related to immune signaling and CD8+ T-cell abundance in the tumor microenvironment. CNA burden was associated with poor overall survival in patients receiving ICB and could improve patient stratification when incorporated with TMB. These findings may guide patient selection for immunotherapy or alternative strategies.

T-cell infiltration and its regulatory mechanisms in cancers: insights at single-cell resolution

Tumor-infiltrating T cells recognize, attack, and clear tumor cells, playing a central role in antitumor immune response. However, certain immune cells can impair this response and help tumor immune escape. Therefore, exploring the factors that influence T-cell infiltration is crucial to understand tumor immunity and improve therapeutic effect of cancer immunotherapy. The use of single-cell RNA sequencing (scRNA-seq) allows the high-resolution analysis of the precise composition of immune cells with different phenotypes and other microenvironmental factors, including non-immune stromal cells and the related molecules in the tumor microenvironment of various cancer types. In this review, we summarized the research progress on T-cell infiltration and the crosstalk of other stromal cells and cytokines during T-cell infiltration using scRNA-seq to provide insights into the mechanisms regulating T-cell infiltration and contribute new perspectives on tumor immunotherapy.

Modulating ferroptosis sensitivity: environmental and cellular targets within the tumor microenvironment

Ferroptosis, a novel form of cell death triggered by iron-dependent phospholipid peroxidation, presents significant therapeutic potential across diverse cancer types. Central to cellular metabolism, the metabolic pathways associated with ferroptosis are discernible in both cancerous and immune cells. This review begins by delving into the intricate reciprocal regulation of ferroptosis between cancer and immune cells. It subsequently details how factors within the tumor microenvironment (TME) such as nutrient scarcity, hypoxia, and cellular density modulate ferroptosis sensitivity. We conclude by offering a comprehensive examination of distinct immunophenotypes and environmental and metabolic targets geared towards enhancing ferroptosis responsiveness within the TME. In sum, tailoring precise ferroptosis interventions and combination strategies to suit the unique TME of specific cancers may herald improved patient outcomes.

Spatial features of specific CD103+CD8+ tissue-resident memory T cell subsets define the prognosis in patients with non-small cell lung cancer

BACKGROUND

Tissue-resident memory T (TRM) cells can reside in the tumor microenvironment and are considered the primary response cells to immunotherapy. Heterogeneity in functional status and spatial distribution may contribute to the controversial role of TRM cells but we know little about it.

METHODS

Through multiplex immunofluorescence (mIF) (CD8, CD103, PD-1, Tim-3, GZMB, CK), the quantity and spatial location of TRM cell subsets were recognized in the tissue from 274 patients with NSCLC after radical surgery. By integrating multiple machine learning methods, we constructed a TRM-based spatial immune signature (TRM-SIS) to predict the prognosis. Furthermore, we conducted a CD103-related gene set enrichment analysis (GSEA) and verified its finding by another mIF panel (CD8, CD103, CK, CD31, Hif-1α).

RESULTS

The density of TRM cells was significantly correlated with the expression of PD-1, Tim-3 and GZMB. Four types of TRM cell subsets was defined, including TRM1 (PD-1-Tim-3-TRM), TRM2 (PD-1+Tim-3-TRM), TRM3 (PD-1-Tim-3+TRM) and TRM4 (PD-1+Tim-3+TRM). The cytotoxicity of TRM2 was the strongest while that of TRM4 was the weakest. Compare with TRM1 and TRM2, TRM3 and TRM4 had better infiltration and stronger interaction with cancer cells. The TRM-SIS was an independent prognostic factor for disease-free survival [HR = 2.43, 95%CI (1.63-3.60), P < 0.001] and showed a better performance than the TNM staging system for recurrence prediction. Furthermore, by CD103-related GSEA and mIF validation, we found a negative association between tumor angiogenesis and infiltration of TRM cells.

CONCLUSIONS

These findings reveal a significant heterogeneity in the functional status and spatial distribution of TRM cells, and support it as a biomarker for the prognosis of NSCLC patients. Regulating TRM cells by targeting tumor angiogenesis may be a potential strategy to improve current immunotherapy.

In Vitro Evaluation of Cancer Cell Immunogenicity and Antigen-Specific T-Cell Cytotoxicity by Flow Cytometry

A cardinal principle of oncoimmunology is that cancer cells can be eliminated by tumor-infiltrating cytotoxic CD8 T lymphocytes. This has been widely demonstrated during the last 20 years and also recently harnessed for therapy. However, emerging evidence indicates that even neoplasms showing striking initial responses to conventional and targeted (immuno)therapies often acquire resistance, resulting in tumor relapse, increased aggressiveness, and metastatization. Indeed, tumors are complex ecosystems whose malignant and nonmalignant cells, constituting the tumor microenvironment, constantly interact and evolve in space and time. Together with patient's own genetic factors, such environmental interplays may curtail antitumor immune responses leading to cancer immune evasion and natural/acquired (immuno)therapy resistance. In this context, cancer stem cells (CSCs) are thought to be the roots of therapy failure. Flow cytometry is a powerful technology that finds extensive applications in cancer biology. It offers several unique advantages as it allows the rapid, quantitative, and multiparametric analysis of cell populations or functions at the single-cell level. In this chapter, we discuss a two-color flow cytometric protocol to evaluate cancer cell immunogenicity by analyzing the proliferative and tumor-killing potential of ovalbumin (OVA)-specific CD8 OT-1 T cells exposed to OVA-expressing MCA205 sarcoma cells and their CSC counterparts.

Immune profiling of pancreatic cancer for radiotherapy with immunotherapy and targeted therapy: Biomarker analysis of a randomized phase 2 trial

PURPOSE

Immunotherapy alone offered limited survival benefits in pancreatic cancer, while the role of immunotherapy-centric combined therapy remains controversial. Therefore, it is required to develop biomarkers to precisely deliver immunotherapy-based multimodality for pancreatic cancer.

METHODS

This is a secondary analysis of an open label, randomized, phase 2 trial, whereas patients with locally recurrent pancreatic cancer after surgery were enrolled. Eligible patients with mutant KRAS and positive immunohistochemical staining of PD-L1 were randomly assigned to receive stereotactic body radiation therapy (SBRT) plus pembrolizumab and trametinib (SBRT + K + M) or SBRT and gemcitabine (SBRT + G). Meanwhile, patients were classified into PD-L1+/tumor infiltrating lymphocytes [TIL(s)]- and PD-L1+/TIL + group for each arm.

RESULTS

A total of 170 patients were enrolled and randomly assigned to receive SBRT + K + M (n = 85) or SBRT + G (n = 85). The improved outcomes have been reported in patients with SBRT + K + M in the previous study. In this secondary analysis, the median overall survival (OS) was 17.2 months (95% CI 14.6-19.8 months) in patients with PD-L1+/TIL + and 12.7 months (95% CI 10.8-14.6 months) in patients with PD-L1+/TIL- (HR 0.62, 95% CI 0.39-0.97, p = 0.036) receiving SBRT + K + M. In SBRT + G group, the median OS was 13.1 months (95% CI 10.9-15.3 months) in patients with PD-L1+/TIL- and 12.7 months (95% CI 9.2-16.2 months) in patients with PD-L1+/TIL+ (HR 0.97, 95% CI 0.62-1.52, p = 0.896). Grade 3 or 4 adverse events were found in 16 patients (30.8%) and 10 patients (30.3%) with PD-L1+/TIL- and PD-L1+/TIL + in SBRT + K + M group respectively; whereas 9 (16.7%) and 8 patients (25.8%) with PD-L1+/TIL- and PD-L1+/TIL + in SBRT + G group.

CONCLUSION

PD-L1, TILs and mutant KRAS may be a biomarker to guide clinical practice of radiotherapy and immunotherapy-based regimens in pancreatic cancer if further combined with MEK inhibitors as targeted therapy.

Revolutionizing Cancer Treatment: Unleashing the Power of Combining Oncolytic Viruses with CAR-T Cells

Oncolytic Viruses (OVs) have emerged as a promising treatment option for cancer thanks to their significant research potential and encouraging results. These viruses exert a profound impact on the tumor microenvironment, making them effective against various types of cancer. In contrast, the efficacy of Chimeric antigen receptor (CAR)-T cell therapy in treating solid tumors is relatively low. The combination of OVs and CAR-T cell therapy, however, is a promising area of research. OVs play a crucial role in enhancing the tumor-suppressive microenvironment, which in turn enables CAR-T cells to function efficiently in the context of solid malignancies. This review aims to provide a comprehensive analysis of the benefits and drawbacks of OV therapy and CAR-T cell therapy, with a focus on the potential of combining these two treatment approaches.

Mesenchymal ovarian cancer cells promote CD8+ T cell exhaustion through the LGALS3-LAG3 axis

Cancer cells often metastasize by undergoing an epithelial-mesenchymal transition (EMT). Although abundance of CD8+ T-cells in the tumor microenvironment correlates with improved survival, mesenchymal cancer cells acquire greater resistance to antitumor immunity in some cancers. We hypothesized the EMT modulates the immune response to ovarian cancer. Here we show that cancer cells from infiltrated/inflamed tumors possess more mesenchymal cells, than excluded and desert tumors. We also noted high expression of LGALS3 is associated with EMT in vivo, a finding validated with in vitro EMT models. Dissecting the cellular communications among populations in the tumor revealed that mesenchymal cancer cells in infiltrated tumors communicate through LGALS3 to LAG3 receptor expressed by CD8+ T cells. We found CD8+ T cells express high levels of LAG3, a marker of T cell exhaustion. The results indicate that EMT in ovarian cancer cells promotes interactions between cancer cells and T cells through the LGALS3 - LAG3 axis, which could increase T cell exhaustion in infiltrated tumors, dampening antitumor immunity.

Pre-treatment inflamed tumor immune microenvironment is associated with FOLFIRINOX response in pancreatic cancer

Introduction

Pancreatic adenocarcinoma (PDAC) is an aggressive tumor with limited response to both chemotherapy and immunotherapy. Pre-treatment tumor features within the tumor immune microenvironment (TiME) may influence treatment response. We hypothesized that the pre-treatment TiME composition differs between metastatic and primary lesions and would be associated with response to modified FOLFIRINOX (mFFX) or gemcitabine-based (Gem-based) therapy.

Methods

Using RNAseq data from a cohort of treatment-naïve, advanced PDAC patients in the COMPASS trial, differential gene expression analysis of key immunomodulatory genes in were analyzed based on multiple parameters including tumor site, response to mFFX, and response to Gem-based treatment. The relative proportions of immune cell infiltration were defined using CIBERSORTx and Dirichlet regression.

Results

145 samples were included in the analysis; 83 received mFFX, 62 received Gem-based therapy. Metastatic liver samples had both increased macrophage (1.2 times more, p < 0.05) and increased eosinophil infiltration (1.4 times more, p < 0.05) compared to primary lesion samples. Further analysis of the specific macrophage phenotypes revealed an increased M2 macrophage fraction in the liver samples. The pre-treatment CD8 T-cell, dendritic cell, and neutrophil infiltration of metastatic samples were associated with therapy response to mFFX (p < 0.05), while mast cell infiltration was associated with response to Gem-based therapy (p < 0.05). Multiple immunoinhibitory genes such as ADORA2A, CSF1R, KDR/VEGFR2, LAG3, PDCD1LG2, and TGFB1 and immunostimulatory genes including C10orf54, CXCL12, and TNFSF14/LIGHT were significantly associated with worse survival in patients who received mFFX (p = 0.01). There were no immunomodulatory genes associated with survival in the Gem-based cohort.

Discussion

Our evidence implies that essential differences in the PDAC TiME exist between primary and metastatic tumors and an inflamed pretreatment TiME is associated with mFFX response. Defining components of the PDAC TiME that influence therapy response will provide opportunities for targeted therapeutic strategies that may need to be accounted for in designing personalized therapy to improve outcomes.

Natural killer cells contribute to 'hot' tumor regression in the allergic inflammatory environment

Systemic immune status influences the elimination of tumor cells. However, it remains unclear how chronic inflammation in allergic diseases affects the tumor microenvironment and tumorigenesis. To investigate tumor progression in a state of heightened allergic inflammation, we established a mouse model of allergic inflammation. We used house dust mite extract to induce a hyper-reactive systemic immune response. Additionally, we subcutaneously inoculated two types of cancer cells (CT26 and 4T1 tumors). We conducted immune profiling of the ex-vivo tumor mass using multicolor flow cytometry staining and performed dynamic analysis of peripheral cytokines to explore the significant relationship between the development of allergic inflammation and tumorigenesis. We found that mice in a state of allergic inflammation were more susceptible to developing tumors. Interestingly, the growth of T cell-inflamed was inhibited in the allergic state, while growth of non-T cell-inflamed was promoted. Further research revealed that natural killer (NK) cells with enhanced tumor-killing or immune-regulating abilities were more active in " hot " tumors. Inhibiting NK cell activity can partially alleviate the impact of allergic inflammation on tumor growth. In summary, our results suggest that NK cells play significant role in suppressing tumor growth in an allergic inflammation mouse model. This phenomenon seems to be closely linked to both the inherent characteristics of the tumor and its interaction with the immune system. The innate immune system can be mobilized to synergize with the adaptive immune system to inhibit tumor growth, which opens a new way for a tumor immunotherapy.

Unleashing the efficacy of immune checkpoint inhibitors for advanced hepatocellular carcinoma: factors, strategies, and ongoing trials

Hepatocellular carcinoma (HCC) is a prevalent primary liver cancer, representing approximately 85% of cases. The diagnosis is often made in the middle and late stages, necessitating systemic treatment as the primary therapeutic option. Despite sorafenib being the established standard of care for advanced HCC in the past decade, the efficacy of systemic therapy remains unsatisfactory, highlighting the need for novel treatment modalities. Recent breakthroughs in immunotherapy have shown promise in HCC treatment, particularly with immune checkpoint inhibitors (ICIs). However, the response rate to ICIs is currently limited to approximately 15%-20% of HCC patients. Recently, ICIs demonstrated greater efficacy in "hot" tumors, highlighting the urgency to devise more effective approaches to transform "cold" tumors into "hot" tumors, thereby enhancing the therapeutic potential of ICIs. This review presented an updated summary of the factors influencing the effectiveness of immunotherapy in HCC treatment, identified potential combination therapies that may improve patient response rates to ICIs, and offered an overview of ongoing clinical trials focusing on ICI-based combination therapy.

Human T cells loaded with superparamagnetic iron oxide nanoparticles retain antigen-specific TCR functionality

Background

Immunotherapy of cancer is an emerging field with the potential to improve long-term survival. Thus far, adoptive transfer of tumor-specific T cells represents an effective treatment option for tumors of the hematological system such as lymphoma, leukemia or myeloma. However, in solid tumors, treatment efficacy is low owing to the immunosuppressive microenvironment, on-target/off-tumor toxicity, limited extravasation out of the blood vessel, or ineffective trafficking of T cells into the tumor region. Superparamagnetic iron oxide nanoparticles (SPIONs) can make cells magnetically controllable for the site-specific enrichment.

Methods

In this study, we investigated the influence of SPION-loading on primary human T cells for the magnetically targeted adoptive T cell therapy. For this, we analyzed cellular mechanics and the T cell response after stimulation via an exogenous T cell receptor (TCR) specific for the melanoma antigen MelanA or the endogenous TCR specific for the cytomegalovirus antigen pp65 and compared them to T cells that had not received SPIONs.

Results

SPION-loading of human T cells showed no influence on cellular mechanics, therefore retaining their ability to deform to external pressure. Additionally, SPION-loading did not impair the T cell proliferation, expression of activation markers, cytokine secretion, and tumor cell killing after antigen-specific activation mediated by the TCR.

Conclusion

In summary, we demonstrated that SPION-loading of T cells did not affect cellular mechanics or the functionality of the endogenous or an exogenous TCR, which allows future approaches using SPIONs for the magnetically enrichment of T cells in solid tumors.

Modulation of Radiation Doses and Chimeric Antigen Receptor T Cells: A Promising New Weapon in Solid Tumors-A Narrative Review

Tumor behavior is determined by its interaction with the tumor microenvironment (TME). Chimeric antigen receptor (CART) cell therapy represents a new form of cellular immunotherapy (IT). Immune cells present a different sensitivity to radiation therapy (RT). RT can affect tumor cells both modifying the TME and inducing DNA damage, with different effects depending on the low and high doses delivered, and can favor the expression of CART cells. CART cells are patients' T cells genetically engineered to recognize surface structure and to eradicate cancer cells. High-dose radiation therapy (HDRT, >10-20 Gy/fractions) converts immunologically "cold" tumors into "hot" ones by inducing necrosis and massive inflammation and death. LDRT (low-dose radiation therapy, >5-10 Gy/fractions) increases the expansion of CART cells and leads to non-immunogenetic death. An innovative approach, defined as the LATTICE technique, combines a high dose in higher FDG- uptake areas and a low dose to the tumor periphery. The association of RT and immune checkpoint inhibitors increases tumor immunogenicity and immune response both in irradiated and non-irradiated sites. The aim of this narrative review is to clarify the knowledge, to date, on CART cell therapy and its possible association with radiation therapy in solid tumors.

Chemokine expression predicts T cell-inflammation and improved survival with checkpoint inhibition across solid cancers

Immune checkpoint inhibitors (ICI) are highly effective in specific cancers where canonical markers of antitumor immunity are used for patient selection. Improved predictors of T cell-inflammation are needed to identify ICI-responsive tumor subsets in additional cancer types. We investigated associations of a 4-chemokine expression signature (c-Score: CCL4, CCL5, CXCL9, CXCL10) with metrics of antitumor immunity across tumor types. Across cancer entities from The Cancer Genome Atlas, subgroups of tumors displayed high expression of the c-Score (c-Scorehi) with increased expression of immune checkpoint (IC) genes and transcriptional hallmarks of the cancer-immunity cycle. There was an incomplete association of the c-Score with high tumor mutation burden (TMB), with only 15% of c-Scorehi tumors displaying ≥10 mutations per megabase. In a heterogeneous pan-cancer cohort of 82 patients, with advanced and previously treated solid cancers, c-Scorehi tumors had a longer median time to progression (103 versus 72 days, P = 0.012) and overall survival (382 versus 196 days, P = 0.038) following ICI therapy initiation, compared to patients with low c-Score expression. We also found c-Score stratification to outperform TMB assignment for overall survival prediction (HR = 0.42 [0.22-0.79], P = 0.008 versus HR = 0.60 [0.29-1.27], P = 0.18, respectively). Assessment of the c-Score using the TIDE and PredictIO databases, which include ICI treatment outcomes from 10 tumor types, provided further support for the c-Score as a predictive ICI therapeutic biomarker. In summary, the c-Score identifies patients with hallmarks of T cell-inflammation and potential response to ICI treatment across cancer types, which is missed by TMB assignment.

Cavitation-Mediated Immunomodulation and Its Use with Checkpoint Inhibitors

The promotion of anti-tumour immune responses can be an effective route to the complete remission of primary and metastatic tumours in a small proportion of patients. Hence, researchers are currently investigating various methods to further characterise and enhance such responses to achieve a beneficial impact across a wider range of patients. Due to its non-invasive, non-ionising, and targetable nature, the application of ultrasound-mediated cavitation has proven to be a popular method to enhance the delivery and activity of immune checkpoint inhibitors. However, to optimise this approach, it is important to understand the biological and physical mechanisms by which cavitation may promote anti-tumour immune responses. Here, the published literature relating to the role that cavitation may play in modulating anti-tumour immunity is therefore assessed.

Tumour microenvironment changes after osimertinib treatment resistance in non-small cell lung cancer

BACKGROUND

Growing evidence suggests that acquired resistance to targeted therapy in non-small cell lung cancer patients is linked to the mutual domestication between the tumour and its surrounding microenvironment.

AIM

Our study aims to explore the remodelling of tumour microenvironment after osimertinib treatment resistance.

METHODS

We took RNA-seq-based tumour immune infiltration analysis using the TIMER 2.0. We carried out flow cytometry assay and real-time cell analysis to explore the interaction between tumour cells and immune cells. In addition, we analysed exosomes via miRNA-seq and label-free proteomics.

RESULTS

Immune infiltration estimation showed a significant decrease in the immune score (P < 0.001), microenvironment score (P < 0.001) and CD8+ T cells (P < 0.05), but an increase in M0 macrophages (P < 0.01) at osimertinib resistance compared to pre-treatment patients. It was demonstrated that exosomes from H1975OR cells could be taken up by macrophages and drove their polarisation towards the M2 phenotype, and the polarised M2 macrophages could reduce the inhibitory effect on tumour cell proliferation. Pre-activated peripheral blood mononuclear cells exhibited a more potent killing effect on H1975OR cells. We also detected a decrease in CD4+HLA-DR- T cells and an increase in CD4+PD1+ T cells after being co-cultured with H1975OR derived exosomes or conditioned medium. Further miRNA-seq and proteomics analysis of exosomes demonstrated that mir-1258-3p and miR-17-5p might participate in this interaction.

CONCLUSIONS

An immunosuppressive environment, characterised by decreased T cell infiltration and activation, whereas increased macrophage infiltration and M2 polarisation, was identified at osimertinib resistance. This interaction may be carried out by tumour-derived exosomes.