Dual Pro- and Anti-Inflammatory Features of Monocyte-Derived Dendritic Cells

Cellular interactions in tumor microenvironment during breast cancer progression: new frontiers and implications for novel therapeutics

The breast cancer tumor microenvironment (TME) is dynamic, with various immune and non-immune cells interacting to regulate tumor progression and anti-tumor immunity. It is now evident that the cells within the TME significantly contribute to breast cancer progression and resistance to various conventional and newly developed anti-tumor therapies. Both immune and non-immune cells in the TME play critical roles in tumor onset, uncontrolled proliferation, metastasis, immune evasion, and resistance to anti-tumor therapies. Consequently, molecular and cellular components of breast TME have emerged as promising therapeutic targets for developing novel treatments. The breast TME primarily comprises cancer cells, stromal cells, vasculature, and infiltrating immune cells. Currently, numerous clinical trials targeting specific TME components of breast cancer are underway. However, the complexity of the TME and its impact on the evasion of anti-tumor immunity necessitate further research to develop novel and improved breast cancer therapies. The multifaceted nature of breast TME cells arises from their phenotypic and functional plasticity, which endows them with both pro and anti-tumor roles during tumor progression. In this review, we discuss current understanding and recent advances in the pro and anti-tumoral functions of TME cells and their implications for developing safe and effective therapies to control breast cancer progress.

Dendritic cells: the yin and yang in disease progression

Dendritic cells (DCs) are antigen presenting cells that link innate and adaptive immunity. DCs have been historically considered as the most effective and potent cell population to capture, process and present antigens to activate naïve T cells and originate favorable immune responses in many diseases, such as cancer. However, in the last decades, it has been observed that DCs not only promote beneficial responses, but also drive the initiation and progression of some pathologies, including inflammatory bowel disease (IBD). In line with those notions, different therapeutic approaches have been tested to enhance or impair the concentration and role of the different DC subsets. The blockade of inhibitory pathways to promote DCs or DC-based vaccines have been successfully assessed in cancer, whereas the targeting of DCs to inhibit their functionality has proved to be favorable in IBD. In this review, we (a) described the general role of DCs, (b) explained the DC subsets and their role in immunogenicity, (c) analyzed the role of DCs in cancer and therapeutic approaches to promote immunogenic DCs and (d) analyzed the role of DCs in IBD and therapeutic approaches to reduced DC-induced inflammation. Therefore, we aimed to highlight the "yin-yang" role of DCs to improve the understand of this type of cells in disease progression.

Targeting IL-12 family cytokines: A potential strategy for type 1 and type 2 diabetes mellitus

Diabetes is a common metabolic disease characterized by an imbalance in blood glucose levels. The pathogenesis of diabetes involves the essential role of cytokines, particularly the IL-12 family cytokines. These cytokines, which have a similar structure, play multiple roles in regulating the immune response. Recent studies have emphasized the importance of IL-12 family cytokines in the development of both type 1 and type 2 diabetes mellitus. As a result, they hold promise as potential therapeutic targets for the treatment of these conditions. This review focuses on the potential of targeting IL-12 family cytokines for diabetes therapy based on their roles in the pathogenesis of both types of diabetes. We have summarized various therapies that target IL-12 family cytokines, including drug therapy, combination therapy, cell therapy, gene therapy, cytokine engineering therapy, and gut microbiota modulation. By analyzing the advantages and disadvantages of these therapies, we have evaluated their feasibility for clinical application and proposed possible solutions to overcome any challenges. In conclusion, targeting IL-12 family cytokines for diabetes therapy provides updated insights into their potential benefits, such as controlling inflammation, preserving islet β cells, reversing the onset of diabetes, and impeding the development of diabetic complications.

The CD40 agonist HERA-CD40L results in enhanced activation of antigen presenting cells, promoting an anti-tumor effect alone and in combination with radiotherapy

Introduction

The ability to modulate and enhance the anti-tumor immune responses is critical in developing novel therapies in cancer. The Tumor Necrosis Factor (TNF) Receptor Super Family (TNFRSF) are potentially excellent targets for modulation which result in specific anti-tumor immune responses. CD40 is a member of the TNFRSF and several clinical therapies are under development. CD40 signaling plays a pivotal role in regulating the immune system from B cell responses to myeloid cell driven activation of T cells. The CD40 signaling axis is well characterized and here we compare next generation HERA-Ligands to conventional monoclonal antibody based immune modulation for the treatment of cancer.

Methods & results

HERA-CD40L is a novel molecule that targets CD40 mediated signal transduction and demonstrates a clear mode of action in generating an activated receptor complex via recruitment of TRAFs, cIAP1, and HOIP, leading to TRAF2 phosphorylation and ultimately resulting in the enhanced activation of key inflammatory/survival pathway and transcription factors such asNFkB, AKT, p38, ERK1/2, JNK, and STAT1 in dendritic cells. Furthermore, HERA-CD40L demonstrated a strong modulation of the tumor microenvironment (TME) via the increase in intratumoral CD8+ T cells and the functional switch from pro-tumor macrophages (TAMs) to anti-tumor macrophages that together results in a significant reduction of tumor growth in a CT26 mouse model. Furthermore, radiotherapy which may have an immunosuppressive modulation of the TME, was shown to have an immunostimulatory effect in combination with HERA-CD40L. Radiotherapy in combination with HERA-CD40L treatment resulted in an increase in detected intratumoral CD4+/8+ T cells compared to RT alone and, additionally, the repolarization of TAMs was also observed, resulting in an inhibition of tumor growth in a TRAMP-C1 mouse model.

Discussion

Taken together, HERA-CD40L resulted in activating signal transduction mechanisms in dendritic cells, resulting in an increase in intratumoral T cells and manipulation of the TME to be pro-inflammatory, repolarizing M2 macrophages to M1, enhancing tumor control.

Mahuang Xixin Fuzi decoction protects the BALB/c-nude mice infected with influenza A virus by reducing inflammatory cytokines storm and weakly regulating SIgA immune response

ETHNOPHARMACOLOGICAL RELEVANCE

Mahuang Xixin Fuzi Decoction (MXF), as a classical prescription of traditional Chinese medicine (TCM), has been used to treat the immunocompromised individuals infected with influenza A virus (IAV).

AIM OF THE STUDY

The study aims to explore the regulatory of MXF on inflammation and secretory immunoglobulin A (SIgA) antibodies immune response in BALB/c-nude mice infected with IAV.

MATERIALS AND METHODS

The BALB/c-nude mice were infected with IAV, then different dosages of MXF were orally administrated to the mice. The weight, rectal temperature, spontaneous activity, spleen index, lung index, pathological changes of lung tissues, and the relative mRNA expression level of H1N1 M gene were measured for the purpose of valuing the antiviral effect of MXF. The expression levels of cytokines in lungs and immunoglobulin A (IgA) in serum of BALB/c-nude mice were determined with Cytometric Bead Array System (CBA). SIgA in bronchoalveolar lavage fluids (BALF) was detected with Enzyme-linked Immunosorbent Assay (ELISA). The mRNA and protein expression levels of B cell activating factor (BAFF), chemokine receptors 10 (CCR10), and polymeric immunoglobulin receptor (pIgR) in the lung tissues, which are related to the secretion of SIgA, were determined by using RT-PCR and Western blot.

RESULTS

MXF could alleviate the clinical features and reduce the severity of viral lung lesions, including improving the body weight, rectal temperature and spontaneous activity of nude mice infected with IAV, increasing spleen index, decreasing lung index, alleviating pathological damage, and decreasing the relative expression level of H1N1 M gene. Levels of pro-inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), interleukin-2 (IL-2), interleukin-12p70 (IL-12p70), and interleukin-17A (IL-17A) were also significantly decreased after treatment with MXF. Interferon-γ (IFN-γ), an antiviral cytokine, was significantly up-regulated in high dose MXF (3.12 g/kg) group. Moreover, after MXF treatment, the expressions of SIgA in BALF and IgA in serum were both at relatively low levels. And the mRNA and protein expressions of BAFF, CCR10, and pIgR were significantly decreased after treatment with MXF.

CONCLUSIONS

MXF has obviously protective effects on BALB/c-nude mice infected with IAV by inhibiting virus replication, calming inflammatory cytokine storm, and regulating SIgA immune response weakly.

GM-CSF, Flt3-L and IL-4 affect viability and function of conventional dendritic cell types 1 and 2

Conventional type 1 dendritic cells (cDC1) and conventional type 2 dendritic cells (cDC2) have attracted increasing attention as alternatives to monocyte-derived dendritic cells (moDCs) in cancer immunotherapy. Use of cDCs for therapy has been hindered by their low numbers in peripheral blood. In the present study, we found that extensive spontaneous apoptosis and cDC death in culture within 24hrs represent an additional challenge. Different media conditions that maintain cDC viability and function were investigated. CD141+ cDC1 and CD1c+ cDC2 were isolated from healthy blood donor buffy coats. Low viabilities were found with CellGenix DC, RPMI-1640, and X-VIVO 15 standard culture media and with several supplements at 24hrs and 48hrs. Among multiple factors it was found that GM-CSF improved both cDC1 and cDC2 viability, whereas Flt3-L and IL-4 only increased viability of cDC1 and cDC2, respectively. Combinations of these three cytokines improved viability of both cDCs further, both at 24hrs and 48hrs time points. Although these cytokines have been extensively investigated for their role in myeloid cell differentiation, and are also used clinically, their effects on mature cDCs remain incompletely known, in particular effects on pro-inflammatory or tolerogenic cDC features. HLA-DR, CD80, CD83, CD86, PD-L1 and PD-L2 cDC membrane expressions were relatively little affected by GM-CSF, IL-4 and Flt3-L cytokine supplements compared to the strong induction following Toll-like receptor (TLR) stimulation for 24hrs. With minor exceptions the three cytokines appeared to be permissive to the TLR-induced marker expression. Allogeneic mixed leukocyte reaction showed that the cytokines promoted T-cell proliferation and revealed a potential to boost both Th1 and Th2 polarizing cytokines. GM-CSF and Flt3-L and their combination improved the capability of cDC1 for dextran uptake, while in cDC2, dextran capture was improved by GM-CSF. The data suggest that GM-CSF, IL-4 and Flt3-L and combinations might be beneficial for DC viability and function in vitro. Limited viability of cDCs could be a confounding variable experimentally and in immunotherapy.

The effects of dendritic cell-based vaccines in the tumor microenvironment: Impact on myeloid-derived suppressor cells

Dendritic cells (DCs) are a heterogenous population of professional antigen presenting cells whose main role is diminished in a variety of malignancies, including cancer, leading to ineffective immune responses. Those mechanisms are inhibited due to the immunosuppressive conditions found in the tumor microenvironment (TME), where myeloid-derived suppressor cells (MDSCs), a heterogeneous population of immature myeloid cells known to play a key role in tumor immunoevasion by inhibiting T-cell responses, are extremely accumulated. In addition, it has been demonstrated that MDSCs not only suppress DC functions, but also their maturation and development within the myeloid linage. Considering that an increased number of DCs as well as the improvement in their functions boost antitumor immunity, DC-based vaccines were developed two decades ago, and promising results have been obtained throughout these years. Therefore, the remodeling of the TME promoted by DC vaccination has also been explored. Here, we aim to review the effectiveness of different DCs-based vaccines in murine models and cancer patients, either alone or synergistically combined with other treatments, being especially focused on their effect on the MDSC population.

Pharmacological suppression of glycogen synthase kinase-3 reactivates HIV-1 from latency via activating Wnt/β-catenin/TCF1 axis in CD4+ T cells

ABSTRACTHIV-1 latency posts a major obstacle for HIV-1 eradication. Currently, no desirable latency reversing agents (LRAs) have been implicated in the "Shock and Kill" strategy to mobilize the latently infected cells to be susceptible for clearance by immune responses. Identification of key cellular pathways that modulate HIV-1 latency helps to develop efficient LRAs. In this study, we demonstrate that the Wnt downstream β-catenin/TCF1 pathway is a crucial modulator for HIV-1 latency. The pharmacological activation of the β-catenin/TCF1 pathway with glycogen synthase kinase-3 (GSK3) inhibitors promoted transcription of HIV-1 proviral DNA and reactivated latency in CD4⁺ T cells; the GSK3 kinase inhibitor 6-bromoindirubin-3'-oxime (6-BIO)-induced HIV-1 reactivation was subsequently confirmed in resting CD4⁺ T cells from cART-suppressed patients and SIV-infected rhesus macaques. These findings advance our understanding of the mechanisms responsible for viral latency, and provide the potent LRA that can be further used in conjunction of immunotherapies to eradicate viral reservoirs.

Immunosuppression in Malaria: Do Plasmodium falciparum Parasites Hijack the Host?

Malaria reflects not only a state of immune activation, but also a state of general immune defect or immunosuppression, of complex etiology that can last longer than the actual episode. Inhabitants of malaria-endemic regions with lifelong exposure to the parasite show an exhausted or immune regulatory profile compared to non- or minimally exposed subjects. Several studies and experiments to identify and characterize the cause of this malaria-related immunosuppression have shown that malaria suppresses humoral and cellular responses to both homologous (Plasmodium) and heterologous antigens (e.g., vaccines). However, neither the underlying mechanisms nor the relative involvement of different types of immune cells in immunosuppression during malaria is well understood. Moreover, the implication of the parasite during the different stages of the modulation of immunity has not been addressed in detail. There is growing evidence of a role of immune regulators and cellular components in malaria that may lead to immunosuppression that needs further research. In this review, we summarize the current evidence on how malaria parasites may directly and indirectly induce immunosuppression and investigate the potential role of specific cell types, effector molecules and other immunoregulatory factors.

Celiac Disease Defined by Over-Sensitivity to Gliadin Activation and Superior Antigen Presentation of Dendritic Cells

The autoimmune condition, Celiac Disease (CeD), displays broad clinical symptoms due to gluten exposure. Its genetic association with DQ variants in the human leukocyte antigen (HLA) system has been recognised. Monocyte-derived mature dendritic cells (MoDCs) present gluten peptides through HLA-DQ and co-stimulatory molecules to T lymphocytes, eliciting a cytokine-rich microenvironment. Having access to CeD associated families prevalent in the Czech Republic, this study utilised an in vitro model to investigate their differential monocyte profile. The higher monocyte yields isolated from PBMCs of CeD patients versus control individuals also reflected the greater proportion of dendritic cells derived from these sources following lipopolysaccharide (LPS)/ peptic-tryptic-gliadin (PTG) fragment stimulation. Cell surface markers of CeD monocytes and MoDCs were subsequently profiled. This foremost study identified a novel bio-profile characterised by elevated CD64 and reduced CD33 levels, unique to CD14++ monocytes of CeD patients. Normalisation to LPS stimulation revealed the increased sensitivity of CeD-MoDCs to PTG, as shown by CD86 and HLA-DQ flow cytometric readouts. Enhanced CD86 and HLA-DQ expression in CeD-MoDCs were revealed by confocal microscopy. Analysis highlighted their dominance at the CeD-MoDC membrane in comparison to controls, reflective of superior antigen presentation ability. In conclusion, this investigative study deciphered the monocytes and MoDCs of CeD patients with the identification of a novel bio-profile marker of potential diagnostic value for clinical interpretation. Herein, the characterisation of CD86 and HLA-DQ as activators to stimulants, along with robust membrane assembly reflective of efficient antigen presentation, offers CeD targeted therapeutic avenues worth further exploration.

Intramuscular Boosting with hIFN-Alpha 2b Enhances BCGphipps-Induced Protection in a Murine Model of Leprosy

Host immunity to Mycobacterium leprae encompasses a spectrum of mechanisms that range from cellular immunity-driven protection to damage associated with humoral immunity as in type-2 leprosy reactions. Although type I interferons (IFNs) participate in eliminating intracellular pathogens, their contribution to the production of antibodies and CD3+ FOXP3+ regulatory T cells (Tregs) in BCG vaccine-mediated protection in leprosy is unknown. BCGphipps (BCGph) priming followed by intramuscular hIFN-α 2b boost significantly reduced lesion size and Mycobacterium lepraemurium growth in the skin. T follicular regulatory cells (TFR), a subset of Tregs induced by immunization or infection, reside in the germinal centers (GCs) and modulate antibody production. We found impaired Treg induction and improved GCs in draining lymph nodes of BCGph primed and hIFN-α 2b boosted mice. Moreover, these mice elicited significant amounts of IL-4 and IL-10 in serum. Thus, our results support the adjuvant properties of hIFN-α 2b in the context of BCGph priming to enhance protective immunity against skin leprosy.

Revisiting Current Concepts on the Tolerogenicity of Steady-State Dendritic Cell Subsets and Their Maturation Stages

The original concept stated that immature dendritic cells (DC) act tolerogenically whereas mature DC behave strictly immunogenically. Meanwhile, it is also accepted that phenotypically mature stages of all conventional DC subsets can promote tolerance as steady-state migratory DC by transporting self-antigens to lymph nodes to exert unique functions on regulatory T cells. We propose that in vivo 1) there is little evidence for a tolerogenic function of immature DC during steady state such as CD4 T cell anergy induction, 2) all tolerance as steady-state migratory DC undergo common as well as subset-specific molecular changes, and 3) these changes differ by quantitative and qualitative markers from immunogenic DC, which allows one to clearly distinguish tolerogenic from immunogenic migratory DC.

Evaluation of β-Catenin Inhibition of Axitinib and Nitazoxanide in Human Monocyte-Derived Dendritic Cells

Modulation of β-catenin signaling has attractive therapeutic potential in cancer immunotherapy. Several studies have found that β-catenin can mediate immune evasion in cancer and promote anti-inflammatory features of antigen-presenting dendritic cells. Many small molecular compounds that inhibit Wnt/β-catenin signaling are currently in clinical development, but none have entered routine clinical use. New inhibitors of β-catenin signaling are consequently desirable. Here, we have tested, in monocyte-derived dendritic cells, the effects of two small molecular compounds, axitinib and nitazoxanide, that previously have been discovered to inhibit β-catenin signaling in colon cancer cells. Immature and lipopolysaccharide-matured dendritic cells prepared from healthy blood donor buffy coats were stimulated with 6-bromoindirubin-3′-oxime (6-BIO) to boost basal β-catenin activity, and the effects of axitinib and nitazoxanide were compared with the commercial β-catenin inhibitor ICG-001. Assays, including genome-wide RNA-sequencing, indicated that neither axitinib nor nitazoxanide demonstrated considerable β-catenin inhibition. Both compounds were found to be less toxic to monocyte-derived dendritic cells than either 6-BIO or ICG-001. Axitinib stimulated several aspects of dendritic cell function, such as IL12-p70 secretion, and counteracted IL-10 secretion, according to the present study. However, neither axitinib nor nitazoxanide were found to be efficient β-catenin inhibitors in monocyte-derived dendritic cells.

Tumor immunological phenotype signature-based high-throughput screening for the discovery of combination immunotherapy compounds

Combination immunotherapy is promising to overcome the limited objective response rates of immune checkpoint blockade (ICB) therapy. Here, a tumor immunological phenotype (TIP) gene signature and high-throughput sequencing-based high-throughput screening (HTS2) were combined to identify combination immunotherapy compounds. We firstly defined a TIP gene signature distinguishing "cold" tumors from "hot" tumors. After screening thousands of compounds, we identified that aurora kinase inhibitors (AKIs) could reprogram the expression pattern of TIP genes in triple-negative breast cancer (TNBC) cells. AKIs treatments up-regulate expression of chemokine genes CXCL10 and CXCL11 through inhibiting aurora kinase A (AURKA)-signal transducer and activator of transcription 3 (STAT3) signaling pathway, which promotes effective T cells infiltrating into tumor microenvironment and improves anti-programmed cell death 1 (PD-1) efficacy in preclinical models. Our study established a novel strategy to discover combination immunotherapy compounds and suggested the therapeutic potential of combining AKIs with ICB for the treatment of TNBC.