Both Type I and Type II Interferons Can Activate Antitumor M1 Macrophages When Combined With TLR Stimulation

Pirarubicin combined with TLR3 or TLR4 agonists enhances anti-tumor efficiency

BACKGROUND

Triple-negative breast cancer (TNBC) is prone to relapse due to the lack of effective therapeutic targets. Macrophages are the most abundant immune cells in the tumor microenvironment (TME) of breast cancer. Targeting the cross-talk between macrophages and cancer cells provides a more efficient strategy for anti-tumor therapy. Toll-like receptors (TLRs) are important players involved in macrophage activation, and TLR agonists are known to play roles in cancer therapy. However, the combination strategy of TLR agonists with chemotherapy drugs is still not well characterized.

METHODS

RT-PCR and Western blot were used to detect the expression of TLRs. The communication between breast cancer cells and macrophages were determined by co-culture in vitro. Tumor cells proliferation and migration were investigated by MTT assay and scratch wound assay. The effects of drug combinations and toxic side effects were assessed by immunohistochemistry and Hematoxylin & Eosin staining.

RESULTS

Expression of TLR3 and TLR4 were lower in breast tumor tissues compared with adjacent normal tissues. Patients with higher TLR3 or TLR4 expression levels had a better prognosis than those with lower expression levels. TLR3/4 expression was significantly inhibited when breast cancer cells MDA-MB-231 and E0771 were conditioned-cultured with macrophages in vitro and was also inhibited by pirarubicin (THP). However, the combination of TLR agonists and THP could reverse this response and inhibit the proliferation and migration of breast cancer cells. Additionally, this combination significantly reduced the tumor volume and weight in the murine model, increased the expression of TLR3/4 in mouse breast tumors.

CONCLUSIONS

Our results provide new ideas for the combination strategy of THP with TLR agonists which improves prognosis of breast cancer.

Polymersomal Poly(I:C) Self-Magnifies Antitumor Immunity by Inducing Immunogenic Cell Death and Systemic Immune Activation

Immunotherapy has emerged as a powerful weapon against lung cancer, yet only a fraction of patients respond to the treatment. Poly(I:C) (PIC) effectively triggers both innate and adaptive immunity. It can also induce immunogenic cell death (ICD) in tumor cells. However, its efficacy is hindered by its instability in vivo and limited cellular uptake. To address this, PIC is encapsulated in cRGD-functionalized polymersomes (t-PPIC), which significantly increases its stability and uptake, thus activating dendritic cells (DCs) and inducing apoptosis of lung tumor cells in vitro. In a murine LLC lung tumor model, systemic administration of t-PPIC effectively suppresses tumor growth and leads to survival benefits, with 40% of the mice becoming tumor-free. Notably, t-PPIC provokes stronger apoptosis and ICD in tumor tissue and elicits a more potent stimulation of DCs, recruitment of natural killer (NK) cells, and activation of CD8+ T cells, compared to free PIC and nontargeted PPIC controls. Furthermore, when combined with immune checkpoint inhibitors or radiotherapy, t-PPIC amplifies the antitumor immune response, resulting in complete regression in 60% of the mice. These compelling findings underscore the potential of integrin-targeted polymersomal PIC to enhance antitumor immunity by simultaneously inducing ICD and systemic immune activation.

Application of PARP inhibitors combined with immune checkpoint inhibitors in ovarian cancer

The advent of polyadenosine diphosphate ribose polymerase inhibitors (PARPi) has brought about significant changes in the field of ovarian cancer treatment. However, in 2022, Rucaparib, Olaparib, and Niraparib, had their marketing approval revoked for third-line and subsequent therapies due to an increased potential for adverse events. Consequently, the exploration of new treatment modalities remains imperative. Recently, the integration of PARPi with immune checkpoint inhibitors (ICIs) has emerged as a potential remedy option within the context of ovarian cancer. This article offers a comprehensive examination of the mechanisms and applications of PARPi and ICIs in the treatment of ovarian cancer. It synthesizes the existing evidence supporting their combined use and discusses key considerations that merit attention in ongoing development efforts.

The role of M1/M2 macrophage polarization in primary Sjogren's syndrome

BACKGROUND

The purpose of this study was to investigate the role of macrophage polarization in the pathogenesis of primary Sjogren's syndrome (pSS).

METHODS

Peripheral venous blood samples were collected from 30 patients with pSS and 30 healthy controls. Minor salivary gland samples were abtainted from 10 of these patients and 10 non-pSS controls whose minor salivary gland didn't fulfill the classification criteria for pSS. Enzyme-linked immuno sorbent assay was used to examine the serum concentration of M1/M2 macrophage related cytokines (TNF-a, IL-6, IL-23, IL-4, IL-10 and TGF-β). Flow cytometry was used to examine the numbers of CD86+ M1 macrophages and CD206+ M2 macrophages in peripheral blood mononuclear cells (PBMCs). Immunofluorescence was used to test the infiltration of macrophages in minor salivary glands.

RESULTS

This study observed a significant increase in pSS patients both in the numbers of M1 macrophages in peripheral blood and serum levels of M1-related pro-inflammatory cytokines (IL-6, IL-23 and TNF-α). Conversely, M2 macrophages were downregulated in the peripheral blood of pSS patients. Similarly, in the minor salivary glands of pSS patients, the expression of M1 macrophages was increased, and that of M2 macrophages was decreased. Furthermore, a significantly positive correlation was found between the proportions of M1 macrophages in PBMCs and serum levels of IgG and RF.

CONCLUSIONS

This study reveals the presence of an significant imbalance in M1/M2 macrophages in pSS patients. The M1 polarization of macrophages may play an central role in the pathogenesis of pSS.

Targeting SCD triggers lipotoxicity of cancer cells and enhances anti-tumor immunity in breast cancer brain metastasis mouse models

Breast cancer brain metastases (BCBM) are a significant cause of mortality and are incurable. Thus, identifying BCBM targets that reduce morbidity and mortality is critical. BCBM upregulate Stearoyl-CoA Desaturase (SCD), an enzyme that catalyzes the synthesis of monounsaturated fatty acids, suggesting a potential metabolic vulnerability of BCBM. In this study, we tested the effect of a brain-penetrant clinical-stage inhibitor of SCD (SCDi), on breast cancer cells and mouse models of BCBM. Lipidomics, qPCR, and western blot were used to study the in vitro effects of SCDi. Single-cell RNA sequencing was used to explore the effects of SCDi on cancer and immune cells in a BCBM mouse model. Pharmacological inhibition of SCD markedly reshaped the lipidome of breast cancer cells and resulted in endoplasmic reticulum stress, DNA damage, loss of DNA damage repair, and cytotoxicity. Importantly, SCDi alone or combined with a PARP inhibitor prolonged the survival of BCBM-bearing mice. When tested in a syngeneic mouse model of BCBM, scRNAseq revealed that pharmacological inhibition of SCD enhanced antigen presentation by dendritic cells, was associated with a higher interferon signaling, increased the infiltration of cytotoxic T cells, and decreased the proportion of exhausted T cells and regulatory T cells in the tumor microenvironment (TME). Additionally, pharmacological inhibition of SCD decreased engagement of immunosuppressive pathways, including the PD-1:PD-L1/PD-L2 and PVR/TIGIT axes. These findings suggest that SCD inhibition could be an effective strategy to intrinsically reduce tumor growth and reprogram anti-tumor immunity in the brain microenvironment to treat BCBM.

Signaling by Type I Interferons in Immune Cells: Disease Consequences

This review addresses interferon (IFN) signaling in immune cells and the tumor microenvironment (TME) and examines how this affects cancer progression. The data reveal that IFNs exert dual roles in cancers, dependent on the TME, exhibiting both anti-tumor activity and promoting cancer progression. We discuss the abnormal IFN signaling induced by cancerous cells that alters immune responses to permit their survival and proliferation.

Tumor-associated macrophages affect the treatment of lung cancer

As one of the most common malignant tumors in the world, lung cancer has limited benefits for patients despite its diverse treatment methods due to factors such as personalized medicine targeting histological type, immune checkpoint expression, and driver gene mutations. The high mortality rate of lung cancer is partly due to the immune-suppressive which limits the effectiveness of anti-cancer drugs and induces tumor cell resistance. The currently widely recognized TAM phenotypes include the anti-tumor M1 and pro-tumor M2 phenotypes. M2 macrophages promote the formation of an immune-suppressive microenvironment and hinder immune cell infiltration, thereby inhibiting activation of the anti-tumor immune system and aiding tumor cells in resisting treatment. Analyzing the relationship between different treatment methods and macrophages in the TME can help us better understand the impact of TAMs on lung cancer and confirm the feasibility of targeted TAM therapy. Targeting TAMs to reduce the M2/M1 ratio and reverse the immune-suppressive microenvironment can improve the clinical efficacy of conventional treatment methods and potentially open up more efficient combination treatment strategies, maximizing the benefit for lung cancer patients.

Type I Interferon, Induced by Adenovirus or Adenoviral Vector Infection, Regulates the Cytokine Response to Lipopolysaccharide in a Macrophage Type-Specific Manner

INTRODUCTION

While TLR ligands derived from microbial flora and pathogens are important activators of the innate immune system, a variety of factors such as intracellular bacteria, viruses, and parasites can induce a state of hyperreactivity, causing a dysregulated and potentially life-threatening cytokine over-response upon TLR ligand exposure. Type I interferon (IFN-αβ) is a central mediator in the induction of hypersensitivity and is strongly expressed in splenic conventional dendritic cells (cDC) and marginal zone macrophages (MZM) when mice are infected with adenovirus. This study investigates the ability of adenoviral infection to influence the activation state of the immune system and underlines the importance of considering this state when planning the treatment of patients.

METHODS

Infection with adenovirus-based vectors (Ad) or pretreatment with recombinant IFN-β was used as a model to study hypersensitivity to lipopolysaccharide (LPS) in mice, murine macrophages, and human blood samples. The TNF-α, IL-6, IFN-αβ, and IL-10 responses induced by LPS after pretreatment were measured. Mouse knockout models for MARCO, IFN-αβR, CD14, IRF3, and IRF7 were used to probe the mechanisms of the hypersensitive reaction.

RESULTS

We show that, similar to TNF-α and IL-6 but not IL-10, the induction of IFN-αβ by LPS increases strongly after Ad infection. This is true both in mice and in human blood samples ex vivo, suggesting that the regulatory mechanisms seen in the mouse are also present in humans. In mice, the scavenger receptor MARCO on IFN-αβ-producing cDC and splenic marginal zone macrophages is important for Ad uptake and subsequent cytokine overproduction by LPS. Interestingly, not all IFN-αβ-pretreated macrophage types exposed to LPS exhibit an enhanced TNF-α and IL-6 response. Pretreated alveolar macrophages and alveolar macrophage-like murine cell lines (MPI cells) show enhanced responses, while bone marrow-derived and peritoneal macrophages show a weaker response. This correlates with the respective absence or presence of the anti-inflammatory IL-10 response in these different macrophage types. In contrast, Ad or IFN-β pretreatment enhances the subsequent induction of IFN-αβ in all macrophage types. IRF3 is dispensable for the LPS-induced IFN-αβ overproduction in infected MPI cells and partly dispensable in infected mice, while IRF7 is required. The expression of the LPS co-receptor CD14 is important but not absolutely required for the elicitation of a TNF-α over-response to LPS in Ad-infected mice.

CONCLUSION

Viral infections or application of virus-based vaccines induces type I interferon and can tip the balance of the innate immune system in the direction of hyperreactivity to a subsequent exposure to TLR ligands. The adenoviral model presented here is one example of how multiple factors, both environmental and genetic, affect the physiological responses to pathogens. Being able to measure the current reactivity state of the immune system would have important benefits for infection-specific therapies and for the prevention of vaccination-elicited adverse effects.

[Tumor-associated Macrophage: Emerging Targets for Modulating the Tumor Microenvironment]

Tumor-associated macrophage (TAM) play a crucial role in the immune microenvironment of lung cancer. Through changes in their phenotype and phagocytic functions, TAM contribute to the initiation and progression of lung cancer. By promoting the formation of an immune-suppressive microenvironment and accelerating the growth of abnormal tumor vasculature, TAM facilitate the invasion and metastasis of lung cancer. Macrophages can polarize into different subtypes with distinct functions and characteristics in response to various stimuli, categorized as anti-tumor M1 and pro-tumor M2 types. In tumor tissues, TAM typically polarize into the alternatively activated M2 phenotype, exhibiting inhibitory effects on tumor immunity. This article reviews the role of anti-angiogenic drugs in modulating TAM phenotypes, highlighting their potential to reprogram M2-type TAM into an anti-tumor M1 phenotype. Additionally, the functional alterations of TAM play a significant role in anti-angiogenic therapy and immunotherapy strategies. In summary, the regulation of TAM polarization and function opens up new avenues for lung cancer treatment and may serve as a novel target for modulating the immune microenvironment of tumors.
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Fungal polysaccharides from Inonotus obliquus are agonists for Toll-like receptors and induce macrophage anti-cancer activity

Fungal polysaccharides can exert immunomodulating activity by triggering pattern recognition receptors (PRRs) on innate immune cells such as macrophages. Here, we evaluate six polysaccharides isolated from the medicinal fungus Inonotus obliquus for their ability to activate mouse and human macrophages. We identify two water-soluble polysaccharides, AcF1 and AcF3, being able to trigger several critical antitumor functions of macrophages. AcF1 and AcF3 activate macrophages to secrete nitric oxide and the pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Combined with interferon-γ, the fungal polysaccharides trigger high production of IL-12p70, a central cytokine for antitumor immunity, and induce macrophage-mediated inhibition of cancer cell growth in vitro and in vivo. AcF1 and AcF3 are strong agonists of the PRRs Toll-like receptor 2 (TLR2) and TLR4, and weak agonists of Dectin-1. In comparison, two prototypical particulate β-glucans, one isolated from I. obliquus and one from Saccharomyces cerevisiae (zymosan), are agonists for Dectin-1 but not TLR2 or TLR4, and are unable to trigger anti-cancer functions of macrophages. We conclude that the water-soluble polysaccharides AcF1 and AcF3 from I. obliquus have a strong potential for cancer immunotherapy by triggering multiple PRRs and by inducing potent anti-cancer activity of macrophages.

NSCLC: from tumorigenesis, immune checkpoint misuse to current and future targeted therapy

Non-small cell lung cancer (NSCLC) is largely promoted by a multistep tumorigenesis process involving various genetic and epigenetic alterations, which essentially contribute to the high incidence of mortality among patients with NSCLC. Clinical observations revealed that NSCLC also co-opts a multifaceted immune checkpoint dysregulation as an important driving factor in NSCLC progression and development. For example, a deregulated PI3K/AKT/mTOR pathway has been noticed in 50-70% of NSCLC cases, primarily modulated by mutations in key oncogenes such as ALK, EGFR, KRAS, and others. Additionally, genetic association studies containing patient-specific factors and local reimbursement criteria expose/reveal mutations in EGFR/ALK/ROS/BRAF/KRAS/PD-L1 proteins to determine the suitability of available immunotherapy or tyrosine kinase inhibitor therapy. Thus, the expression of such checkpoints on tumors and immune cells is pivotal in understanding the therapeutic efficacy and has been extensively studied for NSCLC treatments. Therefore, this review summarizes current knowledge in NSCLC tumorigenesis, focusing on its genetic and epigenetic intricacies, immune checkpoint dysregulation, and the evolving landscape of targeted therapies. In the context of current and future therapies, we emphasize the significance of antibodies targeting PD-1/PD-L1 and CTLA-4 interactions as the primary therapeutic strategy for immune system reactivation in NSCLC. Other approaches involving the promising potential of nanobodies, probodies, affibodies, and DARPINs targeting immune checkpoints are also described; these are under active research or clinical trials to mediate immune regulation and reduce cancer progression. This comprehensive review underscores the multifaceted nature, current state and future directions of NSCLC research and treatment.

Targeting eIF4A triggers an interferon response to synergize with chemotherapy and suppress triple-negative breast cancer

Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A with zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages toward an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that zotatifin reprograms the tumor translational landscape, inhibits the translation of Sox4 and Fgfr1, and induces an interferon (IFN) response uniformly across models. The induction of an IFN response is partially due to the inhibition of Sox4 translation by zotatifin. A similar induction of IFN-stimulated genes was observed in breast cancer patient biopsies following zotatifin treatment. Surprisingly, zotatifin significantly synergizes with carboplatin to trigger DNA damage and an even heightened IFN response, resulting in T cell-dependent tumor suppression. These studies identified a vulnerability of eIF4A in TNBC, potential pharmacodynamic biomarkers for zotatifin, and provide a rationale for new combination regimens consisting of zotatifin and chemotherapy or immunotherapy as treatments for TNBC.

Tumor immune microenvironment-modulated nanostrategy for the treatment of lung cancer metastasis

ABSTRACT

As one of the most malignant tumors worldwide, lung cancer, fueled by metastasis, has shown rising mortality rates. However, effective clinical strategies aimed at preventing metastasis are lacking owing to its dynamic multi-step, complicated, and progressive nature. Immunotherapy has shown promise in treating cancer metastasis by reversing the immunosuppressive network of the tumor microenvironment. However, drug resistance inevitably develops due to inadequate delivery of immunostimulants and an uncontrolled immune response. Consequently, adverse effects occur, such as autoimmunity, from the non-specific immune activation and non-specific inflammation in off-target organs. Nanocarriers that improve drug solubility, permeability, stability, bioavailability, as well as sustained, controlled, and targeted delivery can effectively overcome drug resistance and enhance the therapeutic effect while reducing adverse effects. In particular, nanomedicine-based immunotherapy can be utilized to target tumor metastasis, presenting a promising therapeutic strategy for lung cancer. Nanotechnology strategies that boost the immunotherapy effect are classified based on the metastatic cascade related to the tumor immune microenvironment; the breaking away of primary tumors, circulating tumor cell dissemination, and premetastatic niche formation cause distant secondary site colonization. In this review, we focus on the opportunities and challenges of integrating immunotherapy with nanoparticle formulation to establish nanotechnology-based immunotherapy by modulating the tumor microenvironment for preclinical and clinical applications in the management of patients with metastatic lung cancer. We also discuss prospects for the emerging field and the clinical translation potential of these techniques.

Galectin-3 Cooperates with CD47 to Suppress Phagocytosis and T-cell Immunity in Gastric Cancer Peritoneal Metastases

The peritoneal cavity is a common site of gastric adenocarcinoma (GAC) metastasis. Peritoneal carcinomatosis (PC) is resistant to current therapies and confers poor prognosis, highlighting the need to identify new therapeutic targets. CD47 conveys a "don't eat me" signal to myeloid cells upon binding its receptor signal regulatory protein alpha (SIRPα), which helps tumor cells circumvent macrophage phagocytosis and evade innate immune responses. Previous studies demonstrated that the blockade of CD47 alone results in limited clinical benefits, suggesting that other target(s) might need to be inhibited simultaneously with CD47 to elicit a strong antitumor response. Here, we found that CD47 was highly expressed on malignant PC cells, and elevated CD47 was associated with poor prognosis. Galectin-3 (Gal3) expression correlated with CD47 expression, and coexpression of Gal3 and CD47 was significantly associated with diffuse type, poor differentiation, and tumor relapse. Depletion of Gal3 reduced expression of CD47 through inhibition of c-Myc binding to the CD47 promoter. Furthermore, injection of Gal3-deficient tumor cells into either wild-type and Lgals3-/- mice led to a reduction in M2 macrophages and increased T-cell responses compared with Gal3 wild-type tumor cells, indicating that tumor cell-derived Gal3 plays a more important role in GAC progression and phagocytosis than host-derived Gal3. Dual blockade of Gal3 and CD47 collaboratively suppressed tumor growth, increased phagocytosis, repolarized macrophages, and boosted T-cell immune responses. These data uncovered that Gal3 functions together with CD47 to suppress phagocytosis and orchestrate immunosuppression in GAC with PC, which supports exploring a novel combination therapy targeting Gal3 and CD47.

SIGNIFICANCE

Dual inhibition of CD47 and Gal3 enhances tumor cell phagocytosis and reprograms macrophages to overcome the immunosuppressive microenvironment and suppress tumor growth in peritoneal metastasis of gastric adenocarcinoma.

Application of toll-like receptors (TLRs) and their agonists in cancer vaccines and immunotherapy

Toll-like receptors (TLRs) are pattern recognition receptors (PRRs) expressed in various immune cell types and perform multiple purposes and duties involved in the induction of innate and adaptive immunity. Their capability to propagate immunity makes them attractive targets for the expansion of numerous immunotherapeutic approaches targeting cancer. These immunotherapeutic strategies include using TLR ligands/agonists as monotherapy or combined therapeutic strategies. Several TLR agonists have demonstrated significant efficacy in advanced clinical trials. In recent years, multiple reports established the applicability of TLR agonists as adjuvants to chemotherapeutic drugs, radiation, and immunotherapies, including cancer vaccines. Cancer vaccines are a relatively novel approach in the field of cancer immunotherapy and are currently under extensive evaluation for treating different cancers. In the present review, we tried to deliver an inclusive discussion of the significant TLR agonists and discussed their application and challenges to their incorporation into cancer immunotherapy approaches, particularly highlighting the usage of TLR agonists as functional adjuvants to cancer vaccines. Finally, we present the translational potential of rWTC-MBTA vaccination [irradiated whole tumor cells (rWTC) pulsed with phagocytic agonists Mannan-BAM, TLR ligands, and anti-CD40 agonisticAntibody], an autologous cancer vaccine leveraging membrane-bound Mannan-BAM, and the immune-inducing prowess of TLR agonists as a probable immunotherapy in multiple cancer types.

Targeting EIF4A triggers an interferon response to synergize with chemotherapy and suppress triple-negative breast cancer

Protein synthesis is frequently dysregulated in cancer and selective inhibition of mRNA translation represents an attractive cancer therapy. Here, we show that therapeutically targeting the RNA helicase eIF4A by Zotatifin, the first-in-class eIF4A inhibitor, exerts pleiotropic effects on both tumor cells and the tumor immune microenvironment in a diverse cohort of syngeneic triple-negative breast cancer (TNBC) mouse models. Zotatifin not only suppresses tumor cell proliferation but also directly repolarizes macrophages towards an M1-like phenotype and inhibits neutrophil infiltration, which sensitizes tumors to immune checkpoint blockade. Mechanistic studies revealed that Zotatifin reprograms the tumor translational landscape, inhibits the translation of Sox4 and Fgfr1, and induces an interferon response uniformly across models. The induction of an interferon response is partially due to the inhibition of Sox4 translation by Zotatifin. A similar induction of interferon-stimulated genes was observed in breast cancer patient biopsies following Zotatifin treatment. Surprisingly, Zotatifin significantly synergizes with carboplatin to trigger DNA damage and an even heightened interferon response resulting in T cell-dependent tumor suppression. These studies identified a vulnerability of eIF4A in TNBC, potential pharmacodynamic biomarkers for Zotatifin, and provide a rationale for new combination regimens comprising Zotatifin and chemotherapy or immunotherapy as treatments for TNBC.

Styrylpyridinium Derivatives for Fluorescent Cell Imaging

A set of styrylpyridinium (SP) compounds was synthesised in order to study their spectroscopic and cell labelling properties. The compounds comprised different electron donating parts (julolidine, p-dimethylaminophenyl, p-methoxyphenyl, 3,4,5-trimethoxyphenyl), conjugated linkers (vinyl, divinyl), and an electron-withdrawing N-alkylpyridinium part. Geminal or bis-compounds incorporating two styrylpyridinium (bis-SP) moieties at the 1,3-trimethylene unit were synthesised. Compounds comprising a divinyl linker and powerful electron-donating julolidine donor parts possessed intensive fluorescence in the near-infrared region (maximum at ~760 nm). The compounds had rather high cytotoxicity towards the cancerous cell lines HT-1080 and MH-22A; at the same time, basal cytotoxicity towards the NIH3T3 fibroblast cell line ranged from toxic to harmful. SP compound 6e had IC50 values of 1.0 ± 0.03 µg/mL to the cell line HT-1080 and 0.4 µg/mL to MH-22A; however, the basal toxicity LD50 was 477 mg/kg (harmful). The compounds showed large Stokes' shifts, including 195 nm for 6a,b, 240 nm for 6e, and 325 and 352 nm for 6d and 6c, respectively. The highest photoluminescence quantum yield (PLQY) values were observed for 6a,b, which were 15.1 and 12.2%, respectively. The PLQY values for the SP derivatives 6d,e (those with a julolidinyl moiety) were 0.5 and 0.7%, respectively. Cell staining with compound 6e revealed a strong fluorescent signal localised in the cell cytoplasm, whereas the cell nuclei were not stained. SP compound 6e possessed self-assembling properties and formed liposomes with an average diameter of 118 nm. The obtained novel data on near-infrared fluorescent probes could be useful for the development of biocompatible dyes for biomedical applications.

Lysosomes, curcumin, and anti-tumor effects: how are they linked?

Curcumin is a natural active ingredient from traditional Chinese medicine (TCM) that has multi-target characteristics to exert extensive pharmacological activities and thus has been applied in the treatment of various diseases such as cancer, cardiovascular diseases, nervous system, and autoimmune disorders. As an important class of membranous organelles in the intracellular membrane system, lysosomes are involved in biological processes such as programmed cell death, cell metabolism, and immune regulation, thus affecting tumor initiation and progression. It has been shown that curcumin can modulate lysosomal function through the aforementioned pathways, thereby affecting tumor proliferation, invasion, metastasis, drug resistance, and immune function. This review briefly elaborated the regulatory mechanisms of lysosome biogenesis and summarized curcumin-related studies with its anti-tumor effect, providing a reference for the clinical application of curcumin and anti-tumor research targeting lysosomes.

Establishment and Characterization of Free-Floating 3D Macrophage Programming Model in the Presence of Cancer Cell Spheroids

Reprogramming of tumor-associated macrophages (TAMs) is a promising strategy for cancer immunotherapy. Several studies have shown that cancer cells induce/support the formation of immunosuppressive TAMs phenotypes. However, the specific factors that orchestrate this immunosuppressive process are unknown or poorly studied. In vivo studies are expensive, complex, and ethically constrained. Therefore, 3D cell interaction models could become a unique framework for the identification of important TAMs programming factors. In this study, we have established and characterized a new in vitro 3D model for macrophage programming in the presence of cancer cell spheroids. First, it was demonstrated that the profile of cytokines, chemokines, and surface markers of 3D-cultured macrophages did not differ conceptually from monolayer-cultured M1 and M2-programmed macrophages. Second, the possibility of reprogramming macrophages in 3D conditions was investigated. In total, the dynamic changes in 6 surface markers, 11 cytokines, and 22 chemokines were analyzed upon macrophage programming (M1 and M2) and reprogramming (M1→M2 and M2→M1). According to the findings, the reprogramming resulted in a mixed macrophage phenotype that expressed both immunosuppressive and anti-cancer immunostimulatory features. Third, cancer cell spheroids were shown to stimulate the production of immunosuppressive M2 markers as well as pro-tumor cytokines and chemokines. In summary, the newly developed 3D model of cancer cell spheroid/macrophage co-culture under free-floating conditions can be used for studies on macrophage plasticity and for the development of targeted cancer immunotherapy.

Mechanisms of immune modulation in the tumor microenvironment and implications for targeted therapy

The efficacy of cancer therapies is limited to a great extent by immunosuppressive mechanisms within the tumor microenvironment (TME). Numerous immune escape mechanisms have been identified. These include not only processes associated with tumor, immune or stromal cells, but also humoral, metabolic, genetic and epigenetic factors within the TME. The identification of immune escape mechanisms has enabled the development of small molecules, nanomedicines, immune checkpoint inhibitors, adoptive cell and epigenetic therapies that can reprogram the TME and shift the host immune response towards promoting an antitumor effect. These approaches have translated into series of breakthroughs in cancer therapies, some of which have already been implemented in clinical practice. In the present article the authors provide an overview of some of the most important mechanisms of immunosuppression within the TME and the implications for targeted therapies against different cancers.

TLR3 recognition of viral double-stranded RNA in human dental pulp cells is important for the innate immunity

Dental caries or trauma can expose human dental pulp cells (DPCs) to various oral microorganisms, which play an important role in the development of an innate immune response. In the present study, we examined the expression of Toll-like receptors (TLRs) for sensing microbe-associated molecular patterns in human DPCs. Interestingly, real-time PCR analysis demonstrated that TLR3 is the most highly expressed among 10 different TLRs in human DPCs. Poly(I:C), a representative TLR3 ligand mimicking viral double-stranded RNA, potently induced IL-8 expression in a time- and dose-dependent manner. Concordantly, poly(I:C) treatment substantially increased the expression of pro-inflammatory cytokines and chemokines such as IL-6, CCL2, and CXCL10. Human DPCs transfected with TLR3 siRNA exhibited decreased IL-8 production compared with non-targeting siRNA-transfected cells, suggesting that the expression of poly(I:C)-induced inflammatory cytokines is dependent on TLR3. IL-8 secretion induced by poly(I:C) was down-regulated by MAP kinase inhibitors, indicating that the MAP kinase pathway contributes to IL-8 production. Furthermore, C/EBPβ and NF-κB were essential transcriptional factors for poly(I:C)-induced IL-8 expression, as demonstrated by the transient transfection and reporter gene assay. Since lipoproteins are known as major immunostimulatory components of bacteria, human DPCs were treated with poly(I:C) together with Pam2CSK4, a synthetic lipopeptide mimicking bacterial lipoproteins. Pam2CSK4 and poly(I:C) co-treatment synergistically increased IL-8 production in comparison to Pam2CSK4 or poly(I:C) alone, implying that co-infection of viruses and bacteria can synergistically induce inflammatory responses in the dental pulp. Taken together, these results suggest that human DPCs potentially sense and respond to viral double-stranded RNAs, leading to effective induction of innate immune responses.

Tumor-associated macrophages: Prognostic and therapeutic targets for cancer in humans and dogs

Macrophages are ancient, phagocytic immune cells thought to have their origins 500 million years ago in metazoan phylogeny. The understanding of macrophages has evolved to encompass their foundational roles in development, homeostasis, tissue repair, inflammation, and immunity. Notably, macrophages display high plasticity in response to environmental cues, capable of a strikingly wide variety of dynamic gene signatures and phenotypes. Macrophages are also involved in many pathological states including neural disease, asthma, liver disease, heart disease, cancer, and others. In cancer, most tumor-associated immune cells are macrophages, coined tumor-associated macrophages (TAMs). While some TAMs can display anti-tumor properties such as phagocytizing tumor cells and orchestrating an immune response, most macrophages in the tumor microenvironment are immunosuppressive and pro-tumorigenic. Macrophages have been implicated in all stages of cancer. Therefore, interest in manipulating macrophages as a therapeutic strategy against cancer developed as early as the 1970s. Companion dogs are a strong comparative immuno-oncology model for people due to documented similarities in the immune system and spontaneous cancers between the species. Data from clinical trials in humans and dogs can be leveraged to further scientific advancements that benefit both species. This review aims to provide a summary of the current state of knowledge on macrophages in general, and an in-depth review of macrophages as a therapeutic strategy against cancer in humans and companion dogs.

Macrophages at the interface of the co-evolving cancer ecosystem

Macrophages are versatile and heterogeneous innate immune cells undertaking central functions in balancing immune responses and tissue repair to maintain homeostasis. This plasticity, once co-opted by malignant outgrowth, orchestrates manifold reciprocal interactions within the tumor microenvironment, fueling the evolution of the cancer ecosystem. Here, we review the multilayered sources of influence that jointly underpin and longitudinally shape tumor-associated macrophage (TAM) phenotypic states in solid neoplasms. We discuss how, in response to these signals, TAMs steer tumor evolution in the context of natural selection, biological dispersion, and treatment resistance. A number of research frontiers to be tackled are laid down in this review to therapeutically exploit the complex roles of TAMs in cancer. Building upon knowledge obtained from currently applied TAM-targeting strategies and using next generation technologies, we propose conceptual advances and novel therapeutic avenues to rewire TAM multifaceted regulation of the co-evolving cancer ecosystem.

Radiotherapy, PARP Inhibition, and Immune-Checkpoint Blockade: A Triad to Overcome the Double-Edged Effects of Each Single Player

Radiotherapy and, more recently, PARP inhibitors (PARPis) and immune-checkpoint inhibitors represent effective tools in cancer therapy. Radiotherapy exerts its effects not only by damaging DNA and inducing tumor cell death, but also stimulating anti-tumor immune responses. PARPis are known to exert their therapeutic effects by inhibiting DNA repair, and they may be used in combination with radiotherapy. Both radiotherapy and PARPis modulate inflammatory signals and stimulate type I IFN (IFN-I)-dependent immune activation. However, they can also support the development of an immunosuppressive tumor environment and upregulate PD-L1 expression on tumor cells. When provided as monotherapy, immune-checkpoint inhibitors (mainly antibodies to CTLA-4 and the PD-1/PD-L1 axis) result particularly effective only in immunogenic tumors. Combinations of immunotherapy with therapies that favor priming of the immune response to tumor-associated antigens are, therefore, suitable strategies. The widely explored association of radiotherapy and immunotherapy has confirmed this benefit for several cancers. Association with PARPis has also been investigated in clinical trials. Immunotherapy counteracts the immunosuppressive effects of radiotherapy and/or PARPis and synergies with their immunological effects, promoting and unleashing immune responses toward primary and metastatic lesions (abscopal effect). Here, we discuss the beneficial and counterproductive effects of each therapy and how they can synergize to overcome single-therapy limitations.

The crosstalk between the gut microbiota and tumor immunity: Implications for cancer progression and treatment outcomes

The gastrointestinal tract is inhabited by trillions of commensal microorganisms that constitute the gut microbiota. As a main metabolic organ, the gut microbiota has co-evolved in a symbiotic relationship with its host, contributing to physiological homeostasis. Recent advances have provided mechanistic insights into the dual role of the gut microbiota in cancer pathogenesis. Particularly, compelling evidence indicates that the gut microbiota exerts regulatory effects on the host immune system to fight against cancer development. Some microbiota-derived metabolites have been suggested as potential activators of antitumor immunity. On the contrary, the disequilibrium of intestinal microbial communities, a condition termed dysbiosis, can induce cancer development. The altered gut microbiota reprograms the hostile tumor microenvironment (TME), thus allowing cancer cells to avoid immunosurvelliance. Furthermore, the gut microbiota has been associated with the effects and complications of cancer therapy given its prominent immunoregulatory properties. Therapeutic measures that aim to manipulate the interplay between the gut microbiota and tumor immunity may bring new breakthroughs in cancer treatment. Herein, we provide a comprehensive update on the evidence for the implication of the gut microbiota in immune-oncology and discuss the fundamental mechanisms underlying the influence of intestinal microbial communities on systemic cancer therapy, in order to provide important clues toward improving treatment outcomes in cancer patients.

Inflammation Control and Immunotherapeutic Strategies in Comprehensive Cancer Treatment

Tumor growth and expansion are determined by the immunological tumor microenvironment (TME). Typically, early tumorigenic stages are characterized by the immune system not responding or weakly responding to the tumor. However, subsequent tumorigenic stages witness the tumor promoting its growth and metastasis by stimulating tumor-protective (pro-tumor) inflammation to suppress anti-tumor immune responses. Here, we propose the pivotal role of inflammation control in a successful anti-cancer immunotherapy strategy, implying that available and novel immunotherapeutic modalities such as inflammation modulation, antibody (Ab)-based immunostimulation, drug-mediated immunomodulation, cancer vaccination as well as adoptive cell immunotherapy and donor leucocyte transfusion could be applied in cancer patients in a synergistic manner to amplify each other's clinical effects and achieve robust anti-tumor immune reactivity. In addition, the anti-tumor effects of immunotherapy could be enhanced by thermal and/or oxygen therapy. Herein, combined immune-based therapy could prove to be beneficial for patients with advanced cancers, as aiming to provide long-term tumor cell/mass dormancy by restraining compensatory proliferation of surviving cancer cells observed after traditional anti-cancer interventions such as surgery, radiotherapy, and metronomic (low-dose) chemotherapy. We propose the Inflammatory Prognostic Score based on the blood levels of C-reactive protein and lactate dehydrogenase as well as the neutrophil-to-lymphocyte ratio to effectively monitor the effectiveness of comprehensive anti-cancer treatment.

Type I and II interferon signaling in colorectal cancer liver metastasis

Metastatic colorectal cancer is one of the leading causes of cancer-related deaths worldwide. Traditional chemotherapy extended the lifespan of cancer patients by only a few months, but targeted therapies and immunotherapy prolonged survival and led to long-term remissions in some cases. Type I and II interferons have direct pro-apoptotic and anti-proliferative effects on cancer cells and stimulate anti-cancer immunity. As a result, interferon production by cells in the tumor microenvironment is in the spotlight of immunotherapies as it affects the responses of anti-cancer immune cells. However, promoting effects of interferons on colorectal cancer metastasis have also been reported. Here we summarize our knowledge about pro- and anti-metastatic effects of type I and II interferons in colorectal cancer liver metastasis and discuss possible therapeutic implications.

Therapeutic Targeting of TLR4 for Inflammation, Infection, and Cancer: A Perspective for Disaccharide Lipid A Mimetics

The Toll-like receptor 4 (TLR4) signaling pathway plays a central role in the prompt defense against infectious challenge and provides immediate response to Gram-negative bacterial infection. The TLR4/MD-2 complex can sense and respond to various pathogen-associated molecular patterns (PAMPs) with bacterial lipopolysaccharide (LPS) being the most potent and the most frequently occurring activator of the TLR4-mediated inflammation. TLR4 is believed to be both a friend and foe since improperly regulated TLR4 signaling can result in the overactivation of immune responses leading to sepsis, acute lung injury, or pathologic chronic inflammation involved in cancer and autoimmune disease. TLR4 is also considered a legitimate target for vaccine adjuvant development since its activation can boost the adaptive immune responses. The dual action of the TLR4 complex justifies the efforts in the development of both TLR4 antagonists as antisepsis drug candidates or remedies for chronic inflammatory diseases and TLR4 agonists as vaccine adjuvants or immunotherapeutics. In this review, we provide a brief overview of the biochemical evidences for possible pharmacologic applications of TLR4 ligands as therapeutics and report our systematic studies on the design, synthesis, and immunobiological evaluation of carbohydrate-based TLR4 antagonists with nanomolar affinity for MD-2 as well as disaccharide-based TLR4 agonists with picomolar affinity for the TLR4/MD-2 complex.

Tumor cells-derived conditioned medium induced pro-tumoral phenotypes in macrophages through calcium-nuclear factor κB interaction

BACKGROUND

The malignant behaviors of lung cancers are affected by not only cancer cells but also many kinds of stromal cells in tumor microenvironment (TME), including macrophages. Macrophages have been proven to extensively influence tumor progression through several mechanisms, among which switching of macrophages from pro-inflammatory phenotypes (M1-like) to anti-inflammatory phenotypes (M2-like) mediated by transcription factors such as nuclear factor κB (NF-κB) is the most crucial event. The regulation of NF-κB has been well studied, however some details remain fuzzy.

METHODS

Mouse primary bone marrow-derived macrophages (BMDMs) were cultured in Lewis lung carcinoma cell line LL-2-derived conditioned medium (LL-2-CM). Proliferation, migration, and polarization of BMDMs were tested by CCK8, scratch test, transwell, and flow cytometry. Secretion of several cytokines were detected by ELISA or cytometric bead array. To further explore the underlying mechanisms, BMDMs cultured in LL-2-CM were harvested for RNA-seq. Cytosolic calcium was detected by calcium probe Fluo-4-AM. Western blot was applied to exam the activation of NF-κB signal. BAPTA-AM was applied to sequestrate cytosolic calcium to further investigate the relationship between calcium and NF-κB signal. The polarization, calcium alteration, and NF-κB signal activation were further validated in BMDMs treated by CMT-64-derived conditioned medium (CMT-64-CM).

RESULTS

LL-2-CM promoted proliferation, migration, and M2-like polarization of BMDMs and inhibited M1-like polarization of BMDMs. However two pro-inflammatory cytokines, interleukin-6 (IL-6) and tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]) were secreted. RNA-seq indicated that LL-2-CM activated both canonical and non-canonical NF-κB signal in BMDMs. Western blot showed that canonical NF-κB was temporarily elicited and attenuated at 24 h, while non-canonical NF-κB was consistently activated. At the same time, expression of genes that regulate cytosolic calcium ion concentration were down regulated, which caused diminution of cytosolic calcium in BMDMs treated with LL-2-CM. The decreased cytosolic calcium, M2-like polarization, and NF-κB activation was also observed in CMT-64-CM treated BMDMs. On the contrary, elevated cytosolic calcium was observed during M1-like polarization of BMDMs elicited by lipopolysaccharide (LPS). Interestingly, administration of calcium chelator, BAPTA-AM, impeded activation of canonical NF-κB and expression of M1-like marker induced by LPS, which further confirmed the relationship between cytosolic calcium and canonical NF-κB signal.

CONCLUSIONS

In summary, lung cancer cell-derived conditioned medium promoted migration, proliferation, and M2-like polarization of BMDMs. The suppressed M1-like polarization was achieved through mitigating canonical NF-κB pathway via diminishing cytosolic calcium concentration. As far as we know, our work firstly revealed that cytosolic calcium is the key during inhibition of canonical NF-κB and M1-like polarization in macrophages by tumor cells.

Repurposing of Commercially Existing Molecular Target Therapies to Boost the Clinical Efficacy of Immune Checkpoint Blockade

Immune checkpoint blockade (ICB) is now standard of care for several metastatic epithelial cancers and prolongs life expectancy for a significant fraction of patients. A hostile tumor microenvironment (TME) induced by intrinsic oncogenic signaling induces an immunosuppressive niche that protects the tumor cells, limiting the durability and efficacy of ICB therapies. Addition of receptor tyrosine kinase inhibitors (RTKi) as potential modulators of an unfavorable local immune environment has resulted in moderate life expectancy improvement. Though the combination strategy of ICB and RTKi has shown significantly better results compared to individual treatment, the benefits and adverse events are additive whereas synergy of benefit would be preferable. There is therefore a need to investigate the potential of inhibitors other than RTKs to reduce malignant cell survival while enhancing anti-tumor immunity. In the last five years, preclinical studies have focused on using small molecule inhibitors targeting cell cycle and DNA damage regulators such as CDK4/6, CHK1 and poly ADP ribosyl polymerase (PARP) to selectively kill tumor cells and enhance cytotoxic immune responses. This review provides a comprehensive overview of the available drugs that attenuate immunosuppression and overcome hostile TME that could be used to boost FDA-approved ICB efficacy in the near future.

Air pollution exposure induces a decrease in type II interferon response: A paired cohort study

Background

While air pollution is a major issue due to its harmful effects on human health, few studies focus on its impact on the immune system and vulnerability to viral infections. The lockdown declared following the COVID-19 pandemic represents a unique opportunity to study the large-scale impact of variations in air pollutants in real life. We hypothesized that variations in air pollutants modify Th1 response represented by interferon (IFN) γ production.

Methods

We conducted a single center paired pilot cohort study of 58 participants, and a confirmation cohort of 320 participants in Nice (France), with for each cohort two samplings at six months intervals. We correlated the variations in the production of IFNγ after non-specific stimulation of participants’ immune cells with variations in key regulated pollutants: NO₂, O₃, PM_2.5, and PM₁₀ and climate variables. Using linear regression, we studied the effects of variations of each pollutant on the immune response.

Findings

In the pilot cohort, IFNγ production significantly decreased by 25.7% post-lockdown compared to during lockdown, while NO₂ increased significantly by 46.0%. After the adjustment for climate variations during the study period (sunshine and temperature), we observed a significant effect of NO₂ variation on IFNγ production (P=0.03). In the confirmation cohort IFNγ decreased significantly by 47.8% and after adjustment for environmental factors and intrinsic characteristics we observed a significant effect of environmental factors: NO₂, PM₁₀, O₃, climatic conditions (sunshine exposure, relative humidity) on variation in IFNγ production (P=0.005, P<0.001, P=0.001, P=0.002 and P<0.001 respectively) but not independently from the BMI at inclusion and the workplace P=0.007 and P<0.001 respectively).

Interpretation

We show a weakening of the antiviral cellular response in correlation with an increase of pollutants exposition.

Funding

Agence Nationale de la Recherche, Conseil Départemental des Alpes-Maritimes and Region Sud.

Multifunctional nanoparticle potentiates the in situ vaccination effect of radiation therapy and enhances response to immune checkpoint blockade

Radiation therapy (RT) activates an in situ vaccine effect when combined with immune checkpoint blockade (ICB), yet this effect may be limited because RT does not fully optimize tumor antigen presentation or fully overcome suppressive mechanisms in the tumor-immune microenvironment. To overcome this, we develop a multifunctional nanoparticle composed of polylysine, iron oxide, and CpG (PIC) to increase tumor antigen presentation, increase the ratio of M1:M2 tumor-associated macrophages, and enhance stimulation of a type I interferon response in conjunction with RT. In syngeneic immunologically "cold" murine tumor models, the combination of RT, PIC, and ICB significantly improves tumor response and overall survival resulting in cure of many mice and consistent activation of tumor-specific immune memory. Combining RT with PIC to elicit a robust in situ vaccine effect presents a simple and readily translatable strategy to potentiate adaptive anti-tumor immunity and augment response to ICB or potentially other immunotherapies.

Dynamic CD8+ T Cell Cooperation with Macrophages and Monocytes for Successful Cancer Immunotherapy

Simple Summary

Innate and adaptive immunity mutually regulate one another in a dynamic fashion during immune responses. In infectious contexts, positive interactions between macrophages, monocytes and T cells are well recognized, but this is not the case in the field of cancer, where the growth of tumors disturbs the immune response. However, recent advances revealed that successful immunotherapy profoundly remodels the tumor microenvironment, promoting the activation of both T cells and myeloid cells. This review highlights the studies that hint at positive CD8⁺ T cell cooperation with monocytes and macrophages in this context, and discusses the potential mechanisms behind this.

Abstract

The essential roles endorsed by macrophages and monocytes are well established in response to infections, where they contribute to launching the differentiation of specific T-lymphocytes for long-term protection. This knowledge is the result of dynamic studies that can inspire the cancer field, particularly now that cancer immunotherapies elicit some tumor regression. Indeed, immune responses to cancer have mainly been studied after tumors have escaped immune attacks. In particular, the suppressive functions of macrophages were revealed in this context, introducing an obvious bias across the literature. In this review, we will focus on the ways inwhich monocytes and macrophages cooperate with T-lymphocytes, leading to successful immune responses. We will bring together the preclinical studies that have revealed the existence of such positive cooperation in the cancer field, and we will place particular emphasis on proposing the underlying mechanisms. Finally, we will give some perspectives to decipher the functional roles of such T-cell and myeloid cell interactions in the frame of human cancer immunotherapy.

Molecular Mechanisms of Epigenetic Regulation, Inflammation, and Cell Death in ADPKD

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder, which is caused by mutations in the PKD1 and PKD2 genes, characterizing by progressive growth of multiple cysts in the kidneys, eventually leading to end-stage kidney disease (ESKD) and requiring renal replacement therapy. In addition, studies indicate that disease progression is as a result of a combination of factors. Understanding the molecular mechanisms, therefore, should facilitate the development of precise therapeutic strategies for ADPKD treatment. The roles of epigenetic modulation, interstitial inflammation, and regulated cell death have recently become the focuses in ADPKD. Different epigenetic regulators, and the presence of inflammatory markers detectable even before cyst growth, have been linked to cyst progression. Moreover, the infiltration of inflammatory cells, such as macrophages and T cells, have been associated with cyst growth and deteriorating renal function in humans and PKD animal models. There is evidence supporting a direct role of the PKD gene mutations to the regulation of epigenetic mechanisms and inflammatory response in ADPKD. In addition, the role of regulated cell death, including apoptosis, autophagy and ferroptosis, have been investigated in ADPKD. However, there is no consensus whether cell death promotes or delays cyst growth in ADPKD. It is therefore necessary to develop an interactive picture between PKD gene mutations, the epigenome, inflammation, and cell death to understand why inherited PKD gene mutations in patients may result in the dysregulation of these processes that increase the progression of renal cyst formation.

Dissecting Immunosuppressive Cell Communication Patterns Reveals JunB Proto-Oncogene (JUNB) Shaping a Non-Inflamed Tumor Microenvironment

Background: Immunosuppressive cell interactions are responsible for tumor progression and metastasis, as well as anti-tumor immune dysfunction. However, the communication pattern remains unclear.

Methods: We first integrated two single-cell RNA-seq datasets (GSE72056 and GSE103322) of different tumor types to increase the diversity of immunosuppressive cells. Then, based on the analysis results of the communication network, gene regulatory network (GRN), and highly activated pathways, we identified the hub gene in the immunosuppressive tumor microenvironment (TME). To further explore the molecular features of the identified gene, we performed several in silico analysis and in vitro experiments including qRT-PCR and CCK-8 assay.

Results: Four types of immunosuppressive cells were identified, including cancer-associated fibroblasts (CAFs), tumor-associated macrophages (TAMs), tumor-associated neutrophils (TANs), and regulatory T cells (Tregs). Based on GRNs and the interactions of immunosuppressive cells and tumor cells, we constructed an intercellular communication signature that divided the pan-cancer TME into two clusters with distinct immunological features and different responses to immunotherapy. In combination with pathway analysis, JunB proto-oncogene (JUNB) was identified as the hub gene of the immunosuppressive TME, and it designed a non-inflamed TME of bladder cancer according to evidence that JUNB was negatively correlated with immunomodulators, chemokines, major histocompatibility complex molecules, immune cell infiltration abundances, anti-cancer immune response, and immune checkpoint inhibitors. Moreover, JUNB may predict an unfavorable response to immunotherapy. The signaling network of the four types of cells demonstrated the dominant roles of CAFs and TAMs in the TME. Further investigation uncovered that the complement signal was highly activated in the interactions between subpopulations of the inflammatory phenotype of CAFs and TAMs. Functional experiment results demonstrated the upregulated JUNB in bladder cancer tissues and low-immunity-score tissues. In addition, CAFs showed a pro-tumor proliferation effect via JUNB.

Conclusion: Our findings gave insights into the immunosuppressive TME communication network and provided potential therapeutic targets.

The Role of Toll-like Receptor Agonists and Their Nanomedicines for Tumor Immunotherapy

Toll-like receptors (TLRs) are a class of pattern recognition receptors that play a critical role in innate and adaptive immunity. Toll-like receptor agonists (TLRa) as vaccine adjuvant candidates have become one of the recent research hotspots in the cancer immunomodulatory field. Nevertheless, numerous current systemic deliveries of TLRa are inappropriate for clinical adoption due to their low efficiency and systemic adverse reactions. TLRa-loaded nanoparticles are capable of ameliorating the risk of immune-related toxicity and of strengthening tumor suppression and eradication. Herein, we first briefly depict the patterns of TLRa, followed by the mechanism of agonists at those targets. Second, we summarize the emerging applications of TLRa-loaded nanomedicines as state-of-the-art strategies to advance cancer immunotherapy. Additionally, we outline perspectives related to the development of nanomedicine-based TLRa combined with other therapeutic modalities for malignancies immunotherapy.

The SUMOylation inhibitor subasumstat potentiates rituximab activity by IFN1-dependent macrophage and NK cell stimulation

Small ubiquitin-like modifier (SUMO) is a member of a ubiquitin-like protein superfamily. SUMOylation is a reversible posttranslational modification that has been implicated in the regulation of various cellular processes including inflammatory responses and expression of type 1 interferons (IFN1). In this report, we have explored the activity of the selective small molecule SUMOylation inhibitor subasumstat (TAK-981) in promoting antitumor innate immune responses. We demonstrate that treatment with TAK-981 results in IFN1-dependent macrophage and natural killer (NK) cell activation, promoting macrophage phagocytosis and NK cell cytotoxicity in ex vivo assays. Furthermore, pretreatment with TAK-981 enhanced macrophage phagocytosis or NK cell cytotoxicity against CD20+ target cells in combination with the anti-CD20 antibody rituximab. In vivo studies demonstrated enhanced antitumor activity of TAK-981 and rituximab in CD20+ lymphoma xenograft models. Combination of TAK-981 with anti-CD38 antibody daratumumab also resulted in enhanced antitumor activity. TAK-981 is currently being studied in phase 1 clinical trials (#NCT03648372, #NCT04074330, #NCT04776018, and #NCT04381650; www.clinicaltrials.gov) for the treatment of patients with lymphomas and solid tumors.

Targeting PARP1 to Enhance Anticancer Checkpoint Immunotherapy Response: Rationale and Clinical Implications

Reinvigorating the antitumor immune response using immune checkpoint inhibitors (ICIs) has revolutionized the treatment of several malignancies. However, extended use of ICIs has resulted in a cancer-specific response. In tumors considered to be less immunogenic, the response rates were low or null. To overcome resistance and improve the beneficial effects of ICIs, novel strategies focused on ICI-combined therapies have been tested. In particular, poly ADP-ribose polymerase inhibitors (PARPi) are a class of agents with potential for ICI combined therapy. PARPi impairs single-strand break DNA repair; this mechanism involves synthetic lethality in tumor cells with deficient homologous recombination. More recently, novel evidence indicated that PAPRi has the potential to modulate the antitumor immune response by activating antigen-presenting cells, infiltrating effector lymphocytes, and upregulating programmed death ligand-1 in tumors. This review covers the current advances in the immune effects of PARPi, explores the potential rationale for combined therapy with ICIs, and discusses ongoing clinical trials.

Deep Neural Network Modeling Identifies Biomarkers of Response to Immune-checkpoint Therapy

Immunotherapy has shown significant promise as a treatment for cancer, such as lung cancer and melanoma. However, only 10%–30% of the patients respond to treatment with immune checkpoint blockers (ICBs), underscoring the need for biomarkers to predict response to immunotherapy. Here, we developed DeepGeneX, a computational framework that uses advanced deep neural network modeling and feature elimination to reduce single-cell RNA-seq data on ∼26,000 genes to six of the most important genes (CCR7, SELL, GZMB, WARS, GZMH, and LGALS1), that accurately predict response to immunotherapy. We also discovered that the high LGALS1 and WARS-expressing macrophage population represent a biomarker for ICB therapy nonresponders, suggesting that these macrophages may be a target for improving ICB response. Taken together, DeepGeneX enables biomarker discovery and provides an understanding of the molecular basis for the model’s predictions.

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Predicting biomarkers for immunotherapy response remains a challenge

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DeepGeneX combines neural networks with single-cell RNAseq to predict responders

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LGALS1 and WARS-expressing macrophages in nonresponders impact T cell activation

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DeepGeneX enables biomarker discovery and elucidates underlying molecular mechanism

Single-cell transcriptomics links malignant T cells to the tumor immune landscape in cutaneous T cell lymphoma

Cutaneous T cell lymphoma (CTCL) represents a heterogeneous group of non-Hodgkin lymphoma distinguished by the presence of clonal malignant T cells. The heterogeneity of malignant T cells and the complex tumor microenvironment remain poorly characterized. With single-cell RNA analysis and bulk whole-exome sequencing on 19 skin lesions from 15 CTCL patients, we decipher the intra-tumor and inter-lesion diversity of CTCL patients and propose a multi-step tumor evolution model. We further establish a subtyping scheme based on the molecular features of malignant T cells and their pro-tumorigenic microenvironments: the T_CyEM group, demonstrating a cytotoxic effector memory T cell phenotype, shows more M2 macrophages infiltration, while the T_CM group, featured by a central memory T cell phenotype and adverse patient outcome, is infiltrated by highly exhausted CD8⁺ reactive T cells, B cells and Tregs with suppressive activities. Our results establish a solid basis for understanding the nature of CTCL and pave the way for future precision medicine for CTCL patients.

Mesenchymal stromal cells equipped by IFNα empower T cells with potent anti-tumor immunity

Cancer treatments have been revolutionized by the emergence of immune checkpoint blockade therapies. However, only a minority of patients with various tumor types have benefited from such treatments. New strategies focusing on the immune contexture of the tumor tissue microenvironment hold great promises. Here, we created IFNα-overexpressing mesenchymal stromal cells (IFNα-MSCs). Upon direct injection into tumors, we found that these cells are powerful in eliminating several types of tumors. Interestingly, the intra-tumoral injection of IFNα-MSCs could also induce specific anti-tumor effects on distant tumors. These IFNα-MSCs promoted tumor cells to produce CXCL10, which in turn potentiates the infiltration of CD8⁺ T cells in the tumor site. Furthermore, IFNα-MSCs enhanced the expression of granzyme B (GZMB) in CD8⁺ T cells and invigorated their cytotoxicity in a Stat3-dependent manner. Genetic ablation of Stat3 in CD8⁺ T cells impaired the effect of IFNα-MSCs on GZMB expression. Importantly, the combination of IFNα-MSCs and PD-L1 blockade induced an even stronger anti-tumor immunity. Therefore, IFNα-MSCs represent a novel tumor immunotherapy strategy, especially when combined with PD-L1 blockade.

The IRENA lncRNA converts chemotherapy-polarized tumor-suppressing macrophages to tumor-promoting phenotypes in breast cancer

Although chemotherapy can stimulate antitumor immunity by inducing interferon (IFN) response, the functional role of tumor-associated macrophages in this scenario remains unclear. Here, we found that IFN-activated proinflammatory macrophages after neoadjuvant chemotherapy enhanced antitumor immunity but promoted cancer chemoresistance. Mechanistically, IFN induced expression of cytoplasmic long noncoding RNA IFN-responsive nuclear factor-κB activator (IRENA) in macrophages, which triggered nuclear factor-κB signaling via dimerizing protein kinase R and subsequently increased production of protumor inflammatory cytokines. By constructing macrophage-conditional IRENA-knockout mice, we found that targeting IRENA in IFN-activated macrophages abrogated their protumor effects, while retaining their capacity to enhance antitumor immunity. Clinically, IRENA expression in post-chemotherapy macrophages was associated with poor patient survival. These findings indicate that lncRNA can determine the dichotomy of inflammatory cells on cancer progression and antitumor immunity and suggest that targeting IRENA is an effective therapeutic strategy to reversing tumor-promoting inflammation.

Hacking macrophages to combat cancer and inflammatory diseases-Current advances and challenges

Recently, immunotherapy has been served as the treatment of choice for various human pathophysiologies, including inflammatory diseases and cancer. Though most of the current approaches target the lymphoid compartment, macrophages intimately implicated in the induction or resolution of inflammation have rationally gained their place into the therapeutics arena. In this review, I discuss the past and novel groundbreaking strategies focusing on macrophages in different human diseases and highlight the current challenges and considerations underlying their translational potentials.

Paclitaxel Induces Micronucleation and Activates Pro-Inflammatory cGAS-STING Signaling in Triple-Negative Breast Cancer

Taxanes remain one of the most effective medical treatments for breast cancer. Clinical trials have coupled taxanes with immune checkpoint inhibitors in patients with triple-negative breast cancer (TNBC) with promising results. However, the mechanism linking taxanes to immune activation is unclear. To determine if paclitaxel could elicit an antitumoral immune response, we sampled tumor tissues from patients with TNBC receiving weekly paclitaxel (80 mg/m2) and found increased stromal tumor-infiltrating lymphocytes and micronucleation over baseline in three of six samples. At clinically relevant concentrations, paclitaxel can induce chromosome missegregation on multipolar spindles during mitosis. Consequently, post-mitotic cells are multinucleated and contain micronuclei, which often activate cyclic GMP-AMP synthase (cGAS) and may induce a type I IFN response reliant on the stimulator of IFN genes (STING) pathway. Other microtubule-targeting agents, eribulin and vinorelbine, recapitulate this cGAS/STING response and increased the expression of immune checkpoint molecule, PD-L1, in TNBC cell lines. To test the possibility that microtubule-targeting agents sensitize tumors that express cGAS to immune checkpoint inhibitors, we identified 10 patients with TNBC treated with PD-L1 or PD-1, seven of whom also received microtubule-targeting agents. Elevated baseline cGAS expression significantly correlated with treatment response in patients receiving microtubule-targeting agents in combination with immune checkpoint inhibitors. Our study identifies a mechanism by which microtubule-targeting agents can potentiate an immune response in TNBC. Further, baseline cGAS expression may predict patient treatment response to therapies combining microtubule-targeting agents and immune checkpoint inhibitors.

Crosstalk between macrophages and natural killer cells in the tumor microenvironment

The tumor microenvironment (TME) is jointly constructed by a variety of cell types, including tumor cells, immune cells, fibroblasts, and epithelial cells, among others. The cells within the TME interact with each other and with tumor cells to influence tumor development and progression. As the most abundant immune cells in the TME, macrophages regulate the immune network by not only secreting a large amount of versatile cytokines but also expressing a series of ligands or receptors on the surface to interact with other cells directly. Due to their strong plasticity, they exert both immunostimulatory and immunosuppressive effects in the complex TME. The major effector cells of the immune system that directly target cancer cells include but are not limited to natural killer cells (NKs), dendritic cells (DCs), macrophages, polymorphonuclear leukocytes, mast cells, and cytotoxic T lymphocytes (CTLs). Among them, NK cells are the predominant innate lymphocyte subsets that mediate antitumor and antiviral responses. The activation and inhibition of NK cells are regulated by cytokines and the balance between activating and inhibitory receptors. There is an inextricable regulatory relationship between macrophages and NK cells. Herein, we systematically elaborate on the regulatory network between macrophages and NK cells through soluble mediator crosstalk and cell-to-cell interactions. We believe that a better understanding of the crosstalk between macrophages and NKs in the TME will benefit the development of novel macrophage- or NK cell-focused therapeutic strategies with superior efficacies in cancer therapy.

The Yin and Yang of Type I IFNs in Cancer Promotion and Immune Activation

Type I Interferons (IFNs) are key regulators of natural and therapy-induced host defense against viral infection and cancer. Several years of remarkable progress in the field of oncoimmunology have revealed the dual nature of these cytokines. Hence, Type I IFNs may trigger anti-tumoral responses, while leading immune dysfunction and disease progression. This dichotomy relies on the duration and intensity of the transduced signaling, the nature of the unleashed IFN stimulated genes, and the subset of responding cells. Here, we discuss the role of Type I IFNs in the evolving relationship between the host immune system and cancer, as we offer a view of the therapeutic strategies that exploit and require an intact Type I IFN signaling, and the role of these cytokines in inducing adaptive resistance. A deep understanding of the complex, yet highly regulated, network of Type I IFN triggered molecular pathways will help find a timely and immune"logical" way to exploit these cytokines for anticancer therapy.

Reactive Species from Two-Signal Activated Macrophages Interfere with Their Oxygen Consumption Measurements

Metabolic modulation of macrophage activation has emerged as a promising strategy lately in immunotherapeutics. However, macrophages have a broad spectrum of functions and thus, understanding the exact metabolic changes that drive a particular immune response, is of major importance. In our previous work, we have reported a key role of nitric oxide (NO●) in two(2)-signal activated macrophages [M(2-signals)]. Further characterization using metabolic analysis in intact cells, showed that the basal and maximal respiration levels of M(2-signals) were comparable, with cells being unresponsive to the injections-inducd mitochondrial stress. Here, we show that excessive NO● secretion by the M(2-signals) macrophages, interferes with the oxygen (O2) consumption measurements on cells using the seahorse metabolic analyzer. This is attributed mainly to the consumption of ambient oxygen by NO● to form NO2- and/or NO3- but also to the reduction of O2 to superoxide anion (O2●-) by stray electrons from the electron transport chain, leading to the formation of peroxynitrite (ONOO-). We found that reactive species-donors in the absence of cells, produce comparable oxygen consumption rates (OCR) with M(2-signals) macrophages. Furthermore, inhibition of NO● production, partly recovered the respiration of activated macrophages, while external addition of NO● in non-activated macrophages downregulated their OCR levels. Our findings are crucial for the accurate metabolic characterization of cells, especially in cases where reactive nitrogen or oxygen species are produced in excess.

A Monocyte-Orchestrated IFN-I-to-IL-4 Cytokine Axis Instigates Protumoral Macrophages and Thwarts Poly(I:C) Therapy

Type I IFNs (IFN-I) are important for tumor immune surveillance and contribute to the therapeutic responses for numerous treatment regimens. Nevertheless, certain protumoral activities by IFN-I have been increasingly recognized. Indeed, our recent work showed that systemic poly(I:C)/IFN treatment can undesirably trigger high arginase (ARG1) expression within the tumor-associated monocyte/macrophage compartment. Using a line of CRISPR-generated Arg1-YFP reporter knock-in mice, we have determined that a subset of tumor-associated macrophages represent the major Arg1-expressing cell type following poly(I:C)/IFN stimulation. More detailed analyses from in vitro and in vivo models demonstrate a surprising IFN-to-IL-4 cytokine axis in transitional monocytes, which can subsequently stimulate IL-4 target genes, including Arg1, in macrophages. Intriguingly, IFN stimulation of transitional monocytes yielded concurrent M2 (YFP⁺)- and M1 (YFP^-)-skewed macrophage subsets, correlated with an inhibitory crosstalk between IFN-I and IL-4. Genetic abrogation of IL-4 signaling in mice diminished poly(I:C)/IFN-induced ARG1 in tumors, leading to enhanced activation of CD8⁺ T cells and an improved therapeutic effect. The present work uncovered a monocyte-orchestrated macrophage phenotype conversion mechanism that may have broad implications.

Toll-Like Receptor-Based Strategies for Cancer Immunotherapy

Toll-like receptors (TLRs) are expressed and play multiple functional roles in a variety of immune cell types involved in tumor immunity. There are plenty of data on the pharmacological targeting of TLR signaling using agonist molecules that boost the antitumor immune response. A recent body of research has also demonstrated promising strategies for improving the cell-based immunotherapy methods by inducing TLR signaling. These strategies include systemic administration of TLR antagonist along with immune cell transfer and also genetic engineering of the immune cells using TLR signaling components to improve the function of genetically engineered immune cells such as chimeric antigen receptor-modified T cells. Here, we explore the current status of the cancer immunotherapy approaches based on manipulation of TLR signaling to provide a perspective of the underlying rationales and potential clinical applications. Altogether, reviewed publications suggest that TLRs make a potential target for the immunotherapy of cancer.

Assessment of changes in genetic transcriptome in nasal epithelial cells exposed to ozone-aged black carbon and pollen allergen by high-throughput transcriptomics

Background

Air pollution may be associated with increased airway responsiveness to allergens in allergic rhinitis (AR). Ozone-aged environmental black carbon (O₃BC) is an important constituent of atmospheric particulate matter (PM), for which the mechanisms underlying its effects have not been fully elucidated in AR. The objective of the present study was to determine the O₃BC and pollen-induced alterations in the transcriptome in human nasal epithelial cells (hNECs) in vitro.

Methods

hNECs from nasal epithelial mucosal samples of healthy individuals undergoing nasal surgery (turbinoplasty or septoplasty) were established as air–liquid interface (ALI) cultures and exposed to O₃BC, pollen, or a combination of O₃BC+ pollen. Changes in cell viability were analyzed by fluorescence and changes in the transcriptome by high-throughput RNA sequencing (RNA-seq). Several differentially expressed genes were verified by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Enrichment analysis, based on Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) database, was performed to determine major biological functions and pathways involved.

Results

Exposure to ≥ 50 μg/ml O₃BC or 25 μg/ml O₃BC+ 200 μg /ml pollen significantly decreased cell viability of the hNECs compared to control (p < 0.05) or 25 μg/ml O₃BC alone (p < 0.05); whereas exposure to pollen alone did not alter cell viability at any concentration investigated. High-throughput RNA sequencing analysis indicated that there was significant difference in gene expression between pollen or O₃BC alone and O₃BC+ pollen exposed cells. Exposure to 200 μg/ml O₃BC was associated with hypoxia stress response GO terms, whereas exposure to 25 μg/ml O₃BC+ 200 μg/ml pollen was associated with inflammatory response GO terms; including regulation of neutrophil migration and chemotaxis, macrophage differentiation and chemotaxis, mast cell activation, and phagocytosis. KEGG pathway analysis indicated the top 10 upstream regulators to be IL1B, CSF1, CCL2, TLR2, LPL, IGF8, SPP1, CXCL8, FCER1G and IL1RN; of which expressions of inflammation-related genes IL1B, CSF1 and FCER1G were significantly increased.

Conclusion

O₃BC and pollen allergen combined exposure may induce innate immune and allergic inflammation in hNECs, and therefore potentially exacerbate the symptoms of AR in affected individuals.