Immune Milieu Research Articles

Increasing coil temperature of a third-generation e-cigarette device modulates C57BL/6 mouse lung immune cell composition and cytokine milieu independently of aerosol dose

ABSTRACT Higher coil temperature in e-cigarette devices increases the formation of aerosols and toxicants, such as carbonyls. At present, the health implications of vaping at higher temperatures, including exacerbation of pulmonary inflammation, are largely unknown when aerosol dose is considered. To isolate the pulmonary effects of coil temperature, C57BL/6 mice were exposed to e-cigarette aerosols generated at lower (190°C) or higher (250°C) temperature for 3 days, while maintaining a similar chamber aerosol concentration. Increasing coil temperature did not markedly alter aerosol mass-normalized emissions of select carbonyls formed from thermal degradation pathways including formaldehyde, acetaldehyde, propionaldehyde, and acetone under the tested environment. Total bronchoalveolar cells, primarily macrophages, were significantly decreased in mice exposed to aerosols generated with higher coil temperatures compared to lower temperature exposures. The gene expression of IFNβ, IL-1β, TNFα, and IL-10 in mouse lung tissue was significantly reduced following e-cigarette exposure under both conditions, compared to filtered air exposure. Higher temperature exposures further exacerbated downregulation of IFNβ and IL-1β. Data suggest that higher temperature vaping might modulate acute pulmonary immune responses, potentially inducing immune suppression, even when normalized for aerosol dose exposure. Coil temperature thus appears to be an important parameter that needs to be regulated to ensure harm reduction for e-cigarette users.

Obesity uncovers presence of inflammatory lung macrophage subsets with adipose tissue transcriptomic signature in influenza virus infection.

Obesity is a risk factor for increased lung damage and disease severity during influenza virus infection. White adipose tissue (WAT) inflammation is a key driver of disease pathogenesis in obesity. Whether and how obesity modifies lung and WAT immune cell character and function in obesity to amplify influenza disease severity remains unknown. We show that obesity establishes a proinflammatory transcriptome in lung immune cells that is further augmented upon influenza virus infection. Unexpectedly, we also show that influenza virus infection induces expression of inflammatory genes in visceral WAT and modifies WAT immune cell milieu in obesity. Notably, a decrease in WAT macrophage (ATM) populations inversely correlates to increase in infiltrating lung macrophage numbers in obese influenza virus-infected mice. Comparison of both lung and WAT immune cell transcriptional landscapes uncovers a presence of a macrophage subset in the lungs whose transcriptomic signatures matched those of an inflammatory ATM subset preferentially found in obese mice. Adoptive transfer of ATMs from obese mice into lean influenza-virus infected mice promotes host immune cell infiltration to the lungs. Together, our novel findings provide evidence of immune cell transcriptome and character changes in the lungs and WAT of influenza virus infected obese, but not lean, mice and suggest that visceral ATMs may contribute to the overall inflammatory milieu in this setting.

Myeloid derived suppressor cells mediate hepatocyte proliferation and immune suppression during liver regeneration following resection.

Liver regeneration following resection is a complex process relying on coordinated pathways and cell types in the remnant organ. Myeloid-Derived Suppressor Cells (MDSCs) have a role in liver regeneration-related angiogenesis but other roles they may play in this process remain to be elucidated. In this study, we sought to examine the effect of G-MDSCs on hepatocytes proliferation and immune modulation during liver regeneration. Global gene expression profiling of regenerating hepatocytes in mice with CD11b+Ly6G+ MDSCs (G-MDSCs) depletion revealed disrupted transcriptional progression from day one to day two after major liver resection. Key genes and pathways related to hepatocyte proliferation and immune response were differentially expressed upon MDSC depletion. Hepatocytes cellularity increased when co-cultured with G-MDSCs, or treated with amphiregulin, which G-MDSCs upregulate during regeneration. Cytometry by time-of-flight (CyTOF) analysis of the intra-liver immune milieu upon MDSC depletion during regeneration demonstrated increased natural killer cell proportions, alongside changes in other immune cell populations. Taken together, these results provide evidence that MDSCs contribute to early liver regeneration by promoting hepatocyte proliferation and modulating the intra-liver immune response, and illuminate the multifaceted role of MDSCs in liver regeneration.

Unravelling the Reasons Behind Limited Response to Anti-PD Therapy in ATC: A Comprehensive Evaluation of Tumor-Infiltrating Immune Cells and Checkpoints.

Inhibiting the immune checkpoint (ICP) PD-1 based on PD-L1 expression status has revolutionized the treatment of various cancers, yet its efficacy in anaplastic thyroid carcinoma (ATC) remains limited. The therapeutic response depends upon multiple factors, particularly the conduciveness of the tumor's immune milieu. This study comprehensively evaluated and classified ATC's immune microenvironment (IME) to elucidate the factors behind suboptimal response to anti-PD therapy. Utilizing multiplex-immunofluorescence and immunohistochemistry, we retrospectively analyzed 26 cases of ATC for expression of ICPs PD-L1, PD-1, CTLA4, TIM3, and Galectin-9 and tumor-infiltrating cytotoxic T lymphocytes (CTL)-the effector cells, the anti-tumor NK cells, the immune-inhibitory myeloid-derived suppressor (MDSC) and regulatory T (Treg) cells, and B lymphocytes. Most ATCs (65%) exhibited PD-L1 positivity, but only 31%, in addition, had abundant CTL (type I IME), a combination associated with a better response to ICP inhibition. Additionally, PD-1 expression levels on CTL were low/absent in most cases-a "target-missing" situation-unfavorable for an adequate therapeutic response. All but one ATC showed nuclear Galectin-9 expression. The documentation of nuclear expression of Galectin-9 akin to benign thyroid is a first, and its role in ATC pathobiology needs further elucidation. In addition to less abundant PD-1 expression on CTL, the presence of MDSC, Treg, and exhausted cytotoxic T lymphocytes in the immune milieu of ATC can contribute to anti-PD resistance. TIM3, the most frequently expressed ICP on CTL, followed by CTLA4, provides alternate therapeutic targets in ATC. The co-expression of multiple immune checkpoints is of great interest for ATC since these data also open the avenue for combination therapies.

Gastrointestinal germinal center B cell depletion and reduction in IgA+ plasma cells in HIV-1 infection.

Gastrointestinal (GI) B cells and plasma cells (PCs) are critical to mucosal homeostasis and the host response to HIV-1 infection. Here, high-resolution mapping of human B cells and PCs sampled from the colon and ileum during both viremic and suppressed HIV-1 infection identified a reduction in germinal center (GC) B cells and follicular dendritic cells (FDCs) during HIV-1 viremia. Immunoglobulin A-positive (IgA+) PCs are the major cellular output of intestinal GCs and were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling, persisted in antiretroviral therapy (ART)-treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations were associated with changes in the intestinal microbiome composition and systemic inflammation. These findings highlight a key immune defect in the GI mucosa due to HIV-1 viremia.

18F]F-AraG Uptake in Vertebral Bone Marrow May Predict Survival in Patients with Non-Small Cell Lung Cancer Treated with Anti-PD-(L)1 Immunotherapy.

Despite the systemic impact of both cancer and the associated immune response, immuno-PET is predominantly centered on assessment of the immune milieu within the tumor microenvironment. The aim of this study was to assess the value of [18F]F-AraG PET imaging as a noninvasive method for evaluation of system-wide immune status of patients with non-small cell lung cancer before starting immunotherapy. Methods: Eleven patients with advanced non-small cell lung cancer were imaged with [18F]F-AraG before starting immunotherapy. Diagnostic [18F]FDG PET/CT scans were analyzed to assess differences in the extent of disease among patients. SUVmax, SUVmean, and total SUV (SUVtotal) from all tumor lesions, active lymph nodes, spleen, vertebral bone marrow, liver, thyroid, heart, and bowel were extracted from the baseline [18F]F-AraG scans, and discriminant and Kaplan-Meier analyses were performed to test their ability to predict patient response and overall survival. Results: The extent of the disease was variable in the patient cohort, but none of the [18F]FDG biomarkers associated with tumor burden (SUVmax, total metabolic tumor volume, and total lesion glycolysis) was predictive of patient survival. The differences in the [18F]F-AraG and [18F]FDG distribution were observed both within and between lesions, confirming that they capture distinct aspects of the tumor microenvironment. Of the 3 SUV parameters studied, [18F]F-AraG SUVtotal provided a dynamic range suitable for stratifying tumors or patients according to their immune activity. [18F]F-AraG SUVtotal measured in the lumbar and sacral vertebrae differentiated between patients who progressed on therapy and those who did not with 90.9% and 81.8% accuracy, respectively. The Kaplan-Meier analysis revealed that patients with high [18F]F-AraG SUVtotal in the lumbar bone marrow had significantly lower probability of survival than those with a low signal (P = 0.0003). Conclusion: This study highlights the significance of assessing systemic immunity and indicates the potential of the [18F]F-AraG bone marrow signal as a predictive imaging biomarker for patient stratification and treatment guidance.

Epicardial transplantation of antioxidant polyurethane scaffold based human amniotic epithelial stem cell patch for myocardial infarction treatment

Myocardial infarction (MI) is a leading cause of death globally. Stem cell therapy is considered a potential strategy for MI treatment. Transplantation of classic stem cells including embryonic, induced pluripotent and cardiac stem cells exhibited certain repairing effect on MI via supplementing cardiomyocytes, however, their clinical applications were blocked by problems of cell survival, differentiation, functional activity and also biosafety and ethical concerns. Here, we introduced human amniotic epithelial stem cells (hAESCs) featured with immunomodulatory activities, immune-privilege and biosafety, for constructing a stem cell cardiac patch based on porous antioxidant polyurethane (PUR), which demonstrated decent hAESCs compatibility. In rats, the administration of PUR-hAESC patch significantly reduced fibrosis and facilitated vascularization in myocardium after MI and consequently improved cardiac remodeling and function. Mechanistically, the patch provides a beneficial microenvironment for cardiac repair by facilitating a desirable immune response, paracrine modulation and limited oxidative milieu. Our findings may provide a potential therapeutic strategy for MI.

Personalized Treatment Strategies via Integration of Gene Expression Biomarkers in Molecular Profiling of Laryngeal Cancer.

Laryngeal cancer poses a substantial challenge in head and neck oncology, and there is a growing focus on customized medicine techniques. The present state of gene expression indicators in laryngeal cancer and their potential to inform tailored therapy choices are thoroughly examined in this review. We examine significant molecular changes, such as TP53, CDKN2A, PIK3CA, and NOTCH1 mutations, which have been identified as important participants in the development of laryngeal cancer. The study investigates the predictive and prognostic significance of these genetic markers in addition to the function of epigenetic changes such as the methylation of the MGMT promoter. We also go over the importance of cancer stem cell-related gene expression patterns, specifically CD44 and ALDH1A1 expression, in therapy resistance and disease progression. The review focuses on indicators, including PD-L1, CTLA-4, and tumor mutational burden (TMB) in predicting immunotherapy responses, highlighting recent developments in our understanding of the intricate interactions between tumor genetics and the immune milieu. We also investigate the potential for improving prognosis accuracy and treatment selection by the integration of multi-gene expression panels with clinicopathological variables. The necessity for uniform testing and interpretation techniques is one of the difficulties, in implementing these molecular insights into clinical practice, that are discussed. This review seeks to provide a comprehensive framework for promoting personalized cancer therapy by combining the most recent data on gene expression profiling in laryngeal cancer. Molecularly guided treatment options may enhance patient outcomes.

Nicotine is an Immunosuppressant: Implications for Women's Health and Disease

A plethora of evidence supports that nicotine, the primary alkaloid in tobacco products that is generally accepted for maintaining use, is immunoregulatory and may function as an immunosuppressant. Women have unique experiences with use of nicotine-containing products and also undergo significant reproductive transitions throughout their lifespan which may be impacted by nicotine use. Within the extant literature, there is conflicting evidence that nicotine may confer beneficial health effects in specific disease states (e.g., in ulcerative colitis). Use prevalence of nicotine-containing products is exceptionally high in individuals presenting with some comorbid disease states that impact immune system health and can be a risk factor for the development of diseases which disproportionately impact women; however, the mechanisms underlying these relationships are largely unclear. Further, little is known regarding the impacts of nicotine's immunosuppressive effects on women's health during the menopausal transition, which is arguably an inflammatory event characterized by a pro-inflammatory peri-menopause period. Given that post-menopausal women are at a higher risk than men for the development of neurodegenerative diseases such as Alzheimer's disease and are also more vulnerable to negative health effects associated with diseases such as HIV-1 infection, it is important to understand how use of nicotine-containing products may impact the immune milieu in women. In this review, we define instances in which nicotine use confers immunosuppressive, anti-inflammatory, or pro-inflammatory effects in the context of comorbid disease states, and focus on how nicotine impacts neuroimmune signaling to maintain use. We posit that regardless of potential health benefits, nicotine use cessation should be a priority in the clinical care of women. The synthesis of this review demonstrates the importance of systematically defining the relationships between volitional nicotine use, immune system function, and comorbid disease states in women to better understand how nicotine impacts women's health and disease.

SHH Signaling as a Key Player in Endometrial Cancer: Unveiling the Correlation with Good Prognosis, Low Proliferation, and Anti-Tumor Immune Milieu.

Endometrial Cancer (EC) is one of the most common gynecological malignancies. Despite its prevalence, molecular pathways, such as the Sonic Hedgehog (SHH) pathway, have not been extensively studied in the context of EC. This study aims to explore the clinical implications of SHH expression in EC, potentially uncovering new insights into the disease's pathogenesis and offering valuable insights for therapeutic strategies in EC. We utilized data from The Cancer Genome Atlas (TCGA) to divide the dataset into 'High SHH' and 'Low SHH' groups based on a gene signature score derived from SHH pathway-related genes. We explored the clinical and tumor characteristics of these groups, focusing on key cancer hallmarks, including stemness, proliferation, cytolytic activity, tumor micro-environment, and genomic instability. 'High SHH' tumors emerged as a distinct category with favorable clinical and molecular features. These tumors exhibited lower proliferation rates, reduced angiogenesis, and diminished genomic instability, indicating a controlled and less aggressive tumor growth pattern. Moreover, 'High SHH' tumors displayed lower stemness, highlighting a less invasive phenotype. The immune micro-environment in 'High SHH' tumors was enriched with immune cell types, such as macrophage M0, monocytes, B cells, CD8 T cells, CD4 T cells, follicular helper T cells, and natural killer cells. This immune enrichment, coupled with higher cytolytic activity, suggested an improved anti-tumor immune response. Our study sheds light on the clinical significance of Sonic signaling in EC. 'High SHH' tumors exhibit a unique molecular and clinical profile associated with favorable cancer hallmarks, lower grades, and better survival. These findings underscore the potential utility of SHH expression as a robust prognostic biomarker, offering valuable insights for tailored therapeutic strategies in EC. Understanding the SHH pathway's role in EC contributes to our growing knowledge of this cancer and may pave the way for more effective treatment strategies in the future.

Prognostic Significance and Immune Landscape of an Efferocytosis-Related Gene Signature in Bladder Cancer.

Bladder cancer poses a significant global health challenge, underscoring the imperative for precise prognostic instruments to advance patient care. Against the backdrop of efferocytosis's increasingly recognized role in cancer, this research endeavors to develop and authenticate a prognostic signature intricately linked to efferocytosis in bladder cancer. LASSO-COX regression analysis crafted an efferocytosis-related genes risk prognostic model, followed by the construction of a column chart. External validation sets confirmed the predictive accuracy of both the model and chart. Clinical, tumor microenvironment, drug sensitivity, and immunotherapy analyses were employed to comprehensively assess efferocytosis-related scores. The expression of TGFB3 key genes was validated via RT-PCR and western blotting. Further validation included Transwell, Wound healing, Colony formation, and EDU assays. We formulated and validated an efferocytosis-related genes risk model in bladder cancer, comprising 13 core genes. The risk model demonstrated autonomous prognostic significance in both univariate and multivariate Cox analyses. Following the multivariate analysis, we devised a nomogram. Moreover, by utilizing individual risk scores derived from this risk model, we successfully stratified patients into two discernible risk cohorts, unveiling noteworthy variances in immune infiltration profiles and responsiveness to immunotherapy. Notably, the model's key gene TGFB3 was validated through comprehensive experimental investigations, including Transwell assays for migration and invasion and Wound healing assays for motility on the T24 and BIU cell lines. This study has furnished innovative perspectives on an efferocytosis-related prognostic signature, elucidating the prognosis and immune milieu intricacies in patients with bladder cancer.

Exploiting a tumor softening targeted bomb for mechanical gene therapy of chemoresistant Triple-Negative breast cancer

Triple-negative breast cancer (TNBC)-the most aggressive and refractory subtype of breast cancer-plagues many patients. The tumor physical microenvironment (TPME) is characterized by altered stromal composition and extracellular matrix (ECM), which may contribute to tissue stiffness and compromise therapeutic efficacy. Here, based on clinical data analysis and preclinical model validation, we discover that chemoresistant TNBC tends to have a stiffer TPME with a more aggressive genomic landscape, in which lysyl oxidase (LOX) exerts pivotal effects. Anlotinib (An), a multi-targeted tyrosine kinase inhibitor, has great promising potential in the treatment of TNBC. In this regard, we developed a tumor-softening nanobomb (An&siLOX@NPs) that remodels TPME by co-delivering small interfering siRNAs silencing LOX and the anti-angiogenic drug, anlotinib (An). The improved cytosolic delivery of siLOX enables TPME remodeling via reducing deposition and cross-linking between collagen and fibronectin, thereby promoting enrichment of An to improve its therapeutic outcomes. In chemoresistant TNBC, we confirm the An&siLOX@NPs nanobomb-mediated mechanical gene therapy results in obvious inhibition of local tumor outgrowth and prolongs survival. Additionally, softened TPME reactivates intratumoral immune milieu to bolster sensitivity to anti-PD-L1 immunotherapy, completely curing 33.3% of the metastatic tumors, further generating a synergistic anti-tumor efficacy. Collectively, our mechanical gene therapy strategy represents a highly efficient, safe, and versatile anti-drug resistance modality, which not only can solve the snag problem of TNBC treatment but also provides a new demonstration for other tumor treatments.

Interferon regulatory factor 1 mediated inhibition of Treg cell differentiation induces maternal-fetal immune imbalance in preeclampsia

The establishment and maintenance of a successful pregnancy rely heavily on maternal-fetal immune tolerance. Inflammatory and immune mechanisms during pregnancy bear a resemblance to those observed in tumor progression, with Treg cells exhibiting similar immunoregulatory functions in both contexts. Interferon regulatory factor 1 (IRF1) is implicated in modulating the immune milieu within tumors and influencing regulatory T (Treg) cell differentiation. However, the precise association between IRF1 and the onset of preeclampsia (PE) remains unclear. In our investigation, we identified trophoblasts as a significant source of IRF1 expression at the maternal-fetal interface through immunofluorescence analysis. Moreover, heightened levels of IRF1 expression were detected in both placental tissues and peripheral blood samples obtained from PE patients, concomitant with an imbalance in the Th17/Treg ratio. In the peripheral circulation, a notable inverse correlation was observed between IRF1 mRNA levels and Foxp3 mRNA, a transcription factor specific to Treg cells. IRF1 mRNA expression showed a positive association with systolic blood pressure and a negative association with serum albumin levels. Furthermore, co-culturing naïve T cells with supernatants from HTR-8/SV neo cells overexpressing IRF1 resulted in diminished differentiation of T cells into Treg cells. In summary, our study indicates elevated IRF1 expression in the peripheral blood and trophoblast cells of PE patients. Elevated IRF1 in trophoblast cells hinders the differentiation of maternal Treg cells, disrupting maternal-fetal immune tolerance and contributing to PE pathogenesis. Additionally, IRF1 expression correlates with disease severity, suggesting its potential as a novel sensitive target in PE.

Immune checkpoint-regulatable hydrogel-immobilized nanotherapeutics for post-surgical treatment of osteosarcoma

Osteosarcoma recurrence following surgical resection is notoriously prevalent and resistant to chemotherapy (i.e., doxorubicin, DOX) due to its intricate immunosuppressive tumor microenvironment, which remains one of the most life-threatening tumors. In this study, we report the fabrication of an in-situ injectable hydrogel-immobilized nanotherapeutics, tailored to stimulate tumoricidal immunity, thus mitigate both localized osteosarcoma recurrence and the propagation of metastatic tumors subsequent to surgical intervention. Zeolitic imidazolate framework-8 nanoparticles (ZIF NPs), encapsulating a chemotherapeutic agent (i.e., DOX) and immunotherapeutic agents (i.e., αPDL1 and αCD47), are loaded in fibrin hydrogels. These bioengineered constructs are judiciously deployed at surgical sites to orchestrate chemo-immunotherapeutic interventions, effectuated through the controlled release of doxorubicin and the initiation of T cell-mediated immune responses. DOX has the capability to eradicate tumor cells and initiate immunogenic cell death. Notably, αPDL1 engenders the circumvention of PDL1-mediated resistance and dominates metastatic tumor expansion, thereby exerting a pivotal role in the context of systemic immunosuppression. αCD47 blocks the ‘don’t eat me’ signaling axis intrinsic to cancer cells, thereby potentiating their phagocytosis by macrophages. This orchestrated blockade synergistically activates the host immune milieu, thereby repressing tumor recurrence and curtailing the growth of metastatic lesions post-surgical resection in the subcutaneous tumor model (lateral and bilateral) and tibial tumor model (orthotopic and metastatic), respectively. Additionally, zinc ions from the degradation of ZIF NPs acts as the stimulator of interferon genes (STING) agonists to enhance the immunotherapeutic activity against distal and metastatic tumors. The reported immune checkpoint-regulatable cancer immunotherapy activates the host innate and adaptive immune systems, which shows promising for the treatment of osteosarcoma patients.

Identification of new subtypes of breast cancer based on vasculogenic mimicry related genes and a new model for predicting the prognosis of breast cancer

Breast cancer is a malignant tumor that poses a serious threat to women's health, and vasculogenic mimicry (VM) is strongly associated with bad prognosis in breast cancer. However, the relationship between VM and immune infiltration in breast cancer and the underlying mechanisms have not been fully studied. On the basis of the Cancer Genome Atlas (TCGA), Fudan University Shanghai Cancer Center (FUSCC) database, GSCALite database, and gene set enrichment analysis (GSEA) datasets, we investigated the potential involvement of VM-related genes in the development and progression of breast cancer. We analyzed the differential expression, mutation status, methylation status, drug sensitivity, tumor mutation burden (TMB), microsatellite instability (MSI), immune checkpoints, tumor microenvironment (TME), and immune cell infiltration levels associated with VM-related genes in breast cancer. We created two VM subclusters out of breast cancer patients using consensus clustering, and discovered that patients in Cluster 1 had better survival outcomes compared to those in Cluster 2. The infiltration levels of T cells CD4 memory resting and T cells CD8 were higher in Cluster 1, indicating an immune-active state in this cluster. Additionally, we selected three prognostic genes (LAMC2, PIK3CA, and TFPI2) using Lasso, univariate, and multivariate Cox regression and constructed a risk model, which was validated in an external dataset. The prognosis of patients is strongly correlated with aberrant expression of VM-related genes, which advances our knowledge of the tumor immune milieu and enables us to identify previously unidentified breast cancer subtypes. This could direct more potent immunotherapy approaches.

Predictive Signatures for Responses to Checkpoint Blockade in Small-Cell Lung Cancer in Second-Line Therapy Do Not Predict Responses in First-Line Patients.

Although immune checkpoint blockade (ICB) is currently approved for the treatment of extensive-stage small-cell lung cancer (SCLC) in combination with chemotherapy, relatively few patients have demonstrated durable clinical benefit (DCB) to these therapies. Biomarkers predicting responses are needed. Biopsies from 35 SCLC patients treated with ICB were subjected to transcriptomic analysis; gene signatures were assessed for associations with responses. Twenty-one patients were treated with ICB in the first-line setting in combination with platinum-based chemotherapy; fourteen patients were treated in the second-line setting with ICB alone. DCB after ICB in SCLC in the second-line setting (3 of 14 patients) was associated with statistically higher transcriptomic levels of genes associated with inflammation (p = 0.003), antigen presentation machinery (p = 0.03), interferon responses (p < 0.05), and increased CD8 T cells (p = 0.02). In contrast, these gene signatures were not significantly different in the first-line setting. Our data suggest that responses to ICB in SCLC in the second-line setting can be predicted by the baseline inflammatory state of the tumor; however, this strong association with inflammation was not seen in the first-line setting. We postulate that chemotherapy alters the immune milieu allowing a response to ICB. Other biomarkers will be needed to predict responses in first-line therapy patients.

Remodeling the hepatic immune microenvironment and demolishing T cell traps to enhance immunotherapy efficacy in liver metastasis

Immune checkpoint inhibitors (ICIs) exhibit compromised therapeutic efficacy in many patients with advanced cancers, particularly those with liver metastases. Much of this incapability can be ascribed as an irresponsiveness resulting from the “cold” hepatic tumor microenvironment that acts as T cell “traps” for which there currently lack countermeasures. We report a novel nanomedicine that converts the hepatic immune microenvironment to a “hot” phenotype by targeting hepatic macrophage-centric T cell elimination. Using the nanomedicine, composed of KIRA6 (an endothelium reticulum stress inhibitor), α-Tocopherol nanoemulsions, and anti-PD1 antibodies, we found its potency in murine models of orthotopic colorectal tumors and hepatic metastases, restoring immune responses and enhancing anti-tumor effects. A post-treatment scrutiny of the immune microenvironment landscape in the liver reveals repolarization of immunosuppressive hepatic macrophages, upregulation of Th1-like effector CD4+ T cells, and rejuvenation of dendritic cells along with CD8+ T cells. These findings suggest adaptations of liver-centric immune milieu modulation strategies to improve the efficacy of ICIs for a variety of “cold” tumors and their liver metastases.

TRAIL-induced cytokine production via NFKB2 pathway promotes neutrophil chemotaxis and immune suppression in triple negative breast cancers.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential cancer therapeutic that induces apoptosis in cancer cells while sparing the non-malignant cells in preclinical models. However, its efficacy in clinical trials has been limited, suggesting unknown modulatory mechanisms responsible for the lack of TRAIL activity in patients. Here, we hypothesized that TRAIL treatment elicits transcriptional changes in triple negative breast cancer (TNBC) cells that alter the immune milieu. To test this, we performed an RNAseq analysis of MDA-MB-231 cells treated with TRAIL, followed by validation in additional TNBC cell lines. TRAIL significantly induces expression of multiple cytokines such as CXCLs 1, 2, 3, 8,11 and IL-6, which are known to modify neutrophil function. Mechanistically, the induction of these cytokines was predominantly mediated by death receptor 5, caspase 8 (but not caspase 8 enzymatic activity), and the non-canonical NFKB2 pathway. The cytokines produced by the TRAIL-treated TNBC cells enhanced chemotaxis of healthy human donor isolated neutrophils. In vivo , TRAIL treated TNBC murine xenograft tumors showed activation of the NFKB2 pathway, elevated production of CXCLs and IL-6, and increased neutrophil recruitment into the tumors. Moreover, donor isolated neutrophils preincubated in supernatants from TRAIL-treated TNBC cells exhibited impaired cytotoxic effect against TNBC cells. Transcriptomic analysis of neutrophils incubated with either TRAIL alone or supernatant of TRAIL-treated TNBC cells revealed increased expression of inflammatory cytokines, immune modulatory genes, immune checkpoint genes, and genes implicated in delayed neutrophil apoptosis. Functional studies with these neutrophils confirmed their suppressive effect on T cell proliferation and an increase in Treg suppressive phenotype. Collectively, our study demonstrates a novel role of TRAIL-induced NFKB2-dependent cytokine production that promotes neutrophil chemotaxis and immune suppression.

Illuminating immunotherapy response via precision T cell-targeted PET imaging.

Traditionally, immunotherapy agent selection and treatment strategies are guided by biopsy-based histological information. However, biopsies are limited in that they are invasive, provide static information regarding the tumor immune microenvironment, and only sample a small part of one tumor site. The tumor microenvironment is dynamic and heterogenous. As a result, the immune milieu at one site may be distinct from other metastatic sites. These factors make identifying which patients are likely to respond to different immunotherapies and which harbor intrinsic resistance mechanisms difficult to identify based on a biopsy alone. As such, there is significant interest in alternative methodologies that better characterize the tumor immune microenvironment and monitor immunotherapy response. PET imaging potentially offers a non-invasive way to characterize the tumor immune microenvironment at the primary tumor and metastases and allow for longitudinal characterization. Herein, we review pre-clinically and clinically tested T cell-targeted PET radiopharmaceuticals, as T cells have been the dominant immunotherapy target, and their utility in both evaluating response to immunotherapy and in understanding the systemic immune response to treatment with immunotherapeutics.

Extracellular vesicle surface display enhances the therapeutic efficacy and safety profile of cancer immunotherapy

Immunotherapy has emerged as a mainstay in cancer therapy, yet its efficacy is constrained by the risk of immune-related adverse events. In this study, we present a nanoparticle-based delivery system that enhances the therapeutic efficacy of immunomodulatory ligands while concurrently limiting systemic toxicity. We demonstrate that extracellular vesicles (EVs), lipid bilayer enclosed particles released by cells, can be efficiently engineered via iEDDA-mediated conjugation to display multiple immunomodulatory ligands on their surface. Display of immunomodulatory ligands on the EV surface conferred substantial enhancements in signaling efficacy, particularly for tumor necrosis factor receptor superfamily (TNFRSF) agonists, where EV surface display served as an alternative FcγR-independent approach to induce ligand multimerization and efficient receptor crosslinking. EVs displaying a complementary combination of immunotherapeutic ligands were able to shift the tumor immune milieu towards an anti-tumorigenic phenotype and significantly suppress tumor burden and increase survival in multiple models of metastatic cancer to a greater extent than an equivalent dose of free ligands. In summary, we present an EV-based delivery platform for cancer immunotherapeutic ligands that facilitates superior anti-tumor responses at significantly lower doses with less side-effects than is possible with conventional delivery approaches.