JAK1/STAT3 activation directly inhibits IL-12 production in dendritic cells by preventing CDK9/P-TEFb recruitment to the p35 promoter

Emerging strategies for treating autoimmune disease with genetically modified dendritic cells

Gene editing of living cells has become a crucial tool in medical research, enabling scientists to address fundamental biological questions and develop novel strategies for disease treatment. This technology has particularly revolutionized adoptive transfer cell therapy products, leading to significant advancements in tumor treatment and offering promising outcomes in managing transplant rejection, autoimmune disorders, and inflammatory diseases. While recent clinical trials have demonstrated the safety of tolerogenic dendritic cell (TolDC) immunotherapy, concerns remain regarding its effectiveness. This review aims to discuss the application of gene editing techniques to enhance the tolerance function of dendritic cells (DCs), with a particular focus on preclinical strategies that are currently being investigated to optimize the tolerogenic phenotype and function of DCs. We explore potential approaches for in vitro generation of TolDCs and provide an overview of emerging strategies for modifying DCs. Additionally, we highlight the primary challenges hindering the clinical adoption of TolDC therapeutics and propose future research directions in this field.

B7-H4 reduction induced by Toxoplasma gondii infection results in dysfunction of decidual dendritic cells by regulating the JAK2/STAT3 pathway

Background

Primary infection of Toxoplasma gondii can cause serious abnormal pregnancy outcomes such as miscarriage and stillbirth. Inhibitory molecule B7-H4 is abundantly expressed in dendritic cells (DCs) and plays an important role in maintaining immune tolerance. However, the role of B7-H4 in decidual DCs (dDCs) in T. gondii-induced abnormal pregnancy outcomes is not clear.

Methods

We established T. gondii-infected abnormal pregnancy model in wild-type (WT) and B7-H4 knockout (B7-H4^−/−) pregnant mice in vivo and cultured primary human dDCs in vitro. The abnormal pregnancy outcomes were observed and the expression of B7-H4, functional molecules (CD80, CD86, and MHC-II or HLA-DR), indoleamine 2,3-dioxygenase (IDO), cytokines (IL-10 and IL-12), and signaling molecules JAK2/STAT3 in dDCs was detected by flow cytometry and Western blot.

Results

Our results showed that T. gondii infection significantly decreased B7-H4 expression in dDCs. In addition, B7-H4^−/− infected pregnant mice showed much more severe abnormal pregnancy outcomes than their counterparts. Importantly, B7-H4^−/− infection further regulated the expression of molecules (CD80, CD86, and MHC-II or HLA-DR), enzyme IDO, and cytokines (IL-10 and IL-12) in dDCs. We further discovered that B7-H4^−/− infection impairs the JAK2/STAT3 pathway, contributing to dDC dysfunction.

Conclusions

Taken together, the results show that reduction of B7-H4 by T. gondii infection significantly modulates the decrease in cytokine IL-10 and enzyme IDO and the increase in cytokine IL-12, contributing to dDC dysfunction. Moreover, the JAK2/STAT3 pathway is involved in the regulation of B7-H4 by T. gondii infection and in the subsequent IDO and cytokine production, which ultimately contributes to abnormal pregnancy outcomes.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05263-1.

Transcriptional activation of CBFβ by CDK11p110 is necessary to promote osteosarcoma cell proliferation

BACKGROUND

Aberrant expression of cyclin-dependent protein kinases (CDK) is a hallmark of cancer. CDK11 plays a crucial role in cancer cell growth and proliferation. However, the molecular mechanisms of CDK11 and CDK11 transcriptionally regulated genes are largely unknown.

METHODS

In this study, we performed a global transcriptional analysis using gene array technology to investigate the transcriptional role of CDK11 in osteosarcoma. The promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay were used to identify direct transcriptional targets of CDK11. Clinical relevance and function of core-binding factor subunit beta (CBFβ) were further accessed in osteosarcoma.

RESULTS

We identified a transcriptional role of protein-DNA interaction for CDK11p110, but not CDK11p58, in the regulation of CBFβ expression in osteosarcoma cells. The CBFβ promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay confirmed that CBFβ is a direct transcriptional target of CDK11. High expression of CBFβ is associated with poor outcome in osteosarcoma patients. Expression of CBFβ contributes to the proliferation and metastatic behavior of osteosarcoma cells.

CONCLUSIONS

These data establish CBFβ as a mediator of CDK11p110 dependent oncogenesis and suggest that targeting the CDK11- CBFβ pathway may be a promising therapeutic strategy for osteosarcoma treatment.

STAT3, a Master Regulator of Anti-Tumor Immune Response

Immune cells in the tumor microenvironment regulate cancer growth. Thus cancer progression is dependent on the activation or repression of transcription programs involved in the proliferation/activation of lymphoid and myeloid cells. One of the main transcription factors involved in many of these pathways is the signal transducer and activator of transcription 3 (STAT3). In this review we will focus on the role of STAT3 and its regulation, e.g. by phosphorylation or acetylation in immune cells and how it might impact immune cell function and tumor progression. Moreover, we will review the ability of STAT3 to regulate checkpoint inhibitors.

STAT3 Activation in Combination with NF-KappaB Inhibition Induces Tolerogenic Dendritic Cells with High Therapeutic Potential to Attenuate Collagen-Induced Arthritis

Dendritic cells (DCs) have the ability to induce tolerance or inflammation in response to self-antigens, which makes them fundamental players in autoimmunity. In this regard, immunogenic DCs produce IL-12 and IL-23 favouring the acquisition of Th1 and Th17 inflammatory phenotypes, respectively, by autoreactive CD4⁺ T-cells, thus promoting autoimmunity. Conversely, tolerogenic DCs produce IL-10 and TGF-β, inducing the generation of CD4⁺ T-cells with suppressive activity (Treg), which promote tolerance to self-constituents. Previous studies have shown that STAT3 signalling in DCs attenuates the production of proinflammatory cytokines, whilst NF-κB activation promotes it. In this study, we aimed to generate DCs displaying strong and constitutive tolerogenic profile to be used as immunotherapy in autoimmunity. To this end, we transduced bone marrow-derived DCs with lentiviral particles codifying for a constitutively active version of STAT3 (constitutively active STAT3 (STAT3ca)) or with a constitutive repressor of NF-κB (IκBα superrepressor (IκBαSR)), and their therapeutic potential was evaluated in a mouse model of arthritis induced by collagen (CIA). Our results show that STAT3ca transduction favoured the production of the anti-inflammatory mediator IL-10, whereas IκBαSR transduction attenuated the expression of the proinflammatory cytokine IL-23 in DCs. Moreover, both STAT3ca-transduced and IκBαSR-transduced DCs separately exerted a mild but significant therapeutic effect reducing the severity of CIA development. Furthermore, when DCs were transduced with both STAT3ca and IκBαSR together, they reduced CIA manifestation significantly stronger than when transduced with only STAT3ca or IκBαSR separately. These results show STAT3 and NF-κB as two important and complementary regulators of the tolerogenic behaviour of DCs, which should be considered as molecular targets in the design of DC-based suppressive immunotherapies for the treatment of autoimmune disorders.

Folic acid supplementation repressed hypoxia-induced inflammatory response via ROS and JAK2/STAT3 pathway in human promyelomonocytic cells

Hypoxia is associated with inflammation and various chronic diseases. Folic acid is known to ameliorate inflammatory reactions, but the metabolism of folic acid protecting against hypoxia-induced injury is still unclear. In our study, we examined the inflammatory signal transduction pathway in human promyelomonocytic cells (THP-1 cells) with or without treatment with folic acid under hypoxic culture conditions. Our results indicated that supplementation with folic acid significantly reduced the levels of interleukin-1β and tumor necrosis factor-α in hypoxic conditions. Treating THP-1 cells with folic acid suppressed oxidative stress and hypoxia-inducible factor-1α in a dose-dependent manner. Folic acid targeted the activation of Janus kinase 2, downregulated the phosphorylation of signal transducer and activator of transcription 3, and decreased the expression of nuclear factor-κB p65 protein in cells. However, the absence of folic acid did not make cells more vulnerable under hypoxic conditions. In conclusion, folic acid efficiently inhibited the inflammatory response of THP-1 cells under hypoxic conditions by inhibiting reactive oxygen species production and the Janus kinase 2/signal transducer and activator of transcription 3 signaling pathway. Our study supports a basis for treatment with folic acid for chronic inflammation, which correlated with hypoxia.

Dopaminergic Stimulation of Myeloid Antigen-Presenting Cells Attenuates Signal Transducer and Activator of Transcription 3-Activation Favouring the Development of Experimental Autoimmune Encephalomyelitis

The dual potential to promote tolerance or inflammation to self-antigens makes dendritic cells (DCs) fundamental players in autoimmunity. Previous results have shown that stimulation of dopamine receptor D5 (DRD5) in DCs potentiates their inflammatory behaviour, favouring the development of experimental autoimmune encephalomyelitis (EAE). Here, we aimed to decipher the underlying mechanism and to test its relevance in multiple sclerosis (MS) patients. Our data shows that DRD5-deficiency confined to DCs in EAE mice resulted in reduced frequencies of CD4⁺ T-cell subsets with inflammatory potential in the central nervous system, including not only Th1 and Th17 cells but also granulocyte-macrophage colony-stimulating factor producers. Importantly, ex vivo depletion of dopamine from DCs resulted in a dramatic reduction of EAE severity, highlighting the relevance of an autocrine loop promoting inflammation in vivo. Mechanistic analyses indicated that DRD5-signalling in both mouse DCs and human monocytes involves the attenuation of signal transducer and activator of transcription 3-activation, a transcription factor that limits the production of the inflammatory cytokines interleukin (IL)-12 and IL-23. Furthermore, we found an exacerbated expression of all dopamine receptors in peripheral blood pro-inflammatory monocytes obtained from MS patients. These findings illustrate a novel mechanism by which myeloid antigen-presenting cells may trigger the onset of their inflammatory behaviour promoting the development of autoimmunity.

Serine protease allergen favours Th2 responses via PAR-2 and STAT3 activation in murine model

BACKGROUND

Protease activity of Per a 10 favours Th2 responses by differential regulation of IL-12p70 and IL-23 cytokine subunits. This study aimed to elucidate the underlying mechanism of differential regulation of IL-12p70 and IL-23.

METHODS

PAR-2 activation was blocked in murine model by administering SAM11 before each sensitization. CD11c⁺ p-STAT3⁺ cells were measured in lungs by flow cytometry. BMDCs were pretreated with SAM11 or isotype control or stattic and stimulated with Per a 10. p-STAT3 levels were measured using Western blot. Transcript levels of IL-12p35, IL-12/23p40 and IL-23p19 were measured using RT-PCR. Cytokine levels were analysed using ELISA.

RESULTS

Protease activity of Per a 10 increased p-STAT3 levels in mouse lungs, which was reduced upon PAR-2 blockage. Percentage of p-STAT3⁺ CD11c⁺ cells was higher in Per a 10-administered mice and was reduced upon PAR-2 blockage. IL-12p35 and IL-12p70 levels were higher, and IL-23p19 and IL-23 levels were lower in both SAM11-treated mice and BMDCs indicating a role of PAR-2-mediated signalling. IL-4, TSLP, IL-17A, EPO activity, total cell count and specific IgE and IgG1 levels were lower in SAM11-administered mice. Inhibiting STAT3 activation via stattic also leads to lower levels of IL-23p19 and IL-23 and higher levels of IL-12p35.

CONCLUSIONS

Per a 10 leads to PAR-2 activation on BMDCs resulting in downstream activation of STAT3 to regulate the balance between IL-12/IL-23 subunits causing a cytokine milieu rich in IL-23 to favour Th2 polarization.

Study on the Inhibitory Effects of Ephedra Aconite Asarum Decoction on LPS-Induced Dendritic Cells

Dendritic cells (DCs) can secrete cytokines stimulated by lipopolysaccharide (LPS), which leads to not just acute inflammatory responses but also Th1 polarization. Furtherly, chronic inflammation or autoimmune diseases could be triggered. As a classic Traditional Chinese Medicine formula, Ephedra Aconite Asarum Decoction with the main ingredients of ephedrine and hypaconitine can show effect on anti-inflammation and immunoregulation. But it remains unclear whether Ephedra Aconite Asarum Decoction controls DCs. In this study, we investigated the effects of Ephedra Aconite Asarum Decoction on LPS-induced bone marrow-derived DCs (BMDCs) in vitro. We found that Ephedra Aconite Asarum Decoction lowered surface costimulators on DCs and reduced the expression of Th1 type cytokines. Yet it is slightly beneficial for shifting to Th2. Our work reveals that the Ephedra Aconite Asarum Decoction can regulate Th1 inflammation through intervening DCs.

The cause and effect of Cryptococcus interactions with the host

Upon Cryptococcus neoformans infection of the host lung, the fungus enters a nutrient poor environment and must adapt to a variety of host-specific stress conditions (temperature, nutrient limitation, pH, CO₂). Fungal spores enter this milieu with limited nutritional reserves, germinate, and begin proliferating by budding as yeast. Although relatively little is known about the initial stages of infection, recent work has characterized changes that occur upon germination. This program and subsequent yeast-phase proliferation progress in a dynamic environment as host nutrient immunity responds to the infection via toxic accumulation or sequestration of essential micronutrients and innate immune cells are recruited to the site of infection. Adaptation to the host environment and evasion of the immune response through pathogenicity factor expression allows proliferation and dissemination to multiple sites throughout the body, including, most significantly for human disease, the central nervous system. Here we will discuss recent insights into mechanisms underlying C. neoformans interactions with the host during infection.

Detection of Janus-activated kinase-1 and its interacting proteins by the method of luminescent oxygen channeling

Janus-activated kinase-1 (JAK1) plays an important role in many signaling pathways, including the JAK–STAT and SOCS pathways.

Targeting tumor tolerance: A new hope for pancreatic cancer therapy?

With a 5-year survival rate of just 8%, pancreatic cancer (PC) is projected to be the second leading cause of cancer deaths by 2030. Most PC patients are not eligible for surgery with curative intent upon diagnosis, emphasizing a need for more effective therapies. However, PC is notoriously resistant to chemoradiation regimens. As an alternative, immune modulating strategies have recently achieved success in melanoma, prompting their application to other solid tumors. For such therapeutic approaches to succeed, a state of immunologic tolerance must be reversed in the tumor microenvironment and that has been especially challenging in PC. Nonetheless, knowledge of the PC immune microenvironment has advanced considerably over the past decade, yielding new insights and perspectives to guide multimodal therapies. In this review, we catalog the historical groundwork and discuss the evolution of the cancer immunology field to its present state with a specific focus on PC. Strategies currently employing immune modulation in PC are reviewed, specifically highlighting 66 clinical trials across the United States and Europe.

Transcriptional Control of Dendritic Cell Development

The dendritic cells (DCs) of the immune system function in innate and adaptive responses by directing activity of various effector cells rather than serving as effectors themselves. DCs and closely related myeloid lineages share expression of many surface receptors, presenting a challenge in distinguishing their unique in vivo functions. Recent work has taken advantage of unique transcriptional programs to identify and manipulate murine DCs in vivo. This work has assigned several nonredundant in vivo functions to distinct DC lineages, consisting of plasmacytoid DCs and several subsets of classical DCs that promote different immune effector modules in response to pathogens. In parallel, a correspondence between human and murine DC subsets has emerged, underlying structural similarities for the DC lineages between these species. Recent work has begun to unravel the transcriptional circuitry that controls the development and diversification of DCs from common progenitors in the bone marrow.

Targeting the gastrointestinal tract to develop novel therapies for HIV

Despite the use of antiretroviral therapy (ART), which delays and/or prevents AIDS pathogenesis, human immunodeficiency virus (HIV)-infected individuals continue to face increased morbidities and mortality rates compared with uninfected individuals. Gastrointestinal (GI) mucosal dysfunction is a key feature of HIV infection, and is associated with mortality. In this study, we review current knowledge about mucosal dysfunction in HIV infection, and describe potential avenues for therapeutic targets to enhance mucosal function and decrease morbidities and mortalities in HIV-infected individuals.