NFAT proteins: key regulators of T-cell development and function

Vitamin D supplementation and calcium: Many-faced gods or nobody in fighting against Corona Virus Disease 2019

In December 2019, Corona Virus Disease 2019 (COVID-19) was first identified and designated as a pandemic in March 2020 due to rapid spread of the virus globally. At the beginning of the pandemic, only a few treatment options, mainly focused on supportive care and repurposing medications, were available. Due to its effects on immune system, vitamin D was a topic of interest during the pandemic, and researchers investigated its potential impact on COVID-19 outcomes. However, the results of studies about the impact of vitamin D on the disease are inconclusive. In the present narrative review, different roles of vitamin D regarding the COVID-19 have been discussed to show that vitamin D supplementation should be recommended carefully.

Calcineurin is an adaptor required for assembly of the TCR signaling complex

The serine/threonine phosphatase calcineurin is a component of the T cell receptor (TCR) signalosome, where it promotes T cell activation by dephosphorylating LckS59. Using small interfering RNA (siRNA)-mediated knockdown and CRISPR-Cas9-targeted genetic disruption of the calcineurin A chain α and β isoforms, we find that calcineurin also functions as an adaptor in TCR-signaled human T cells. Unlike inhibition of its phosphatase activity, in the absence of calcineurin A, TCR signaling results in attenuated actin rearrangement, markedly reduced TCR-Lck microcluster formation and recruitment of the adaptor RhoH, and diminished phosphorylation of critical targets downstream of Lck such as TCRζ and ZAP-70. Reconstitution of deficient T cells with either calcineurin Aα or Aβ restores TCR microcluster formation and signaling, as does reconstitution with a phosphatase-inactive Aα chain. These results assign a non-enzymatic adaptor function to calcineurin in the formation and stabilization of a functional TCR signaling complex.

T cell exhaustion in human cancers

T cell exhaustion refers to a progressive state in which T cells become functionally impaired due to sustained antigenic stimulation, which is characterized by increased expression of immune inhibitory receptors, but weakened effector functions, reduced self-renewal capacity, altered epigenetics, transcriptional programme and metabolism. T cell exhaustion is one of the major causes leading to immune escape of cancer, creating an environment that supports tumor development and metastatic spread. In addition, T cell exhaustion plays a pivotal role to the efficacy of current immunotherapies for cancer. This review aims to provide a comprehensive view of roles of T cell exhaustion in cancer development and progression. We summerized the regulatory mechanisms that involved in T cell exhaustion, including transcription factors, epigenetic and metabolic reprogramming events, and various microenvironmental factors such as cytokines, microorganisms, and tumor autocrine substances. The paper also discussed the challenges posed by T cell exhaustion to cancer immunotherapies, including immune checkpoint blockade (ICB) therapies and chimeric antigen receptor T cell (CAR-T) therapy, highlightsing the obstacles encountered in ICB therapies and CAR-T therapies due to T cell exhaustion. Finally, the article provides an overview of current therapeutic options aimed to reversing or alleviating T cell exhaustion in ICB and CAR-T therapies. These therapeutic approaches seek to overcome T cell exhaustion and enhance the effectiveness of immunotherapies in treating tumors.

Multiscale photocatalytic proximity labeling reveals cell surface neighbors on and between cells

Proximity labeling proteomics (PLP) strategies are powerful approaches to yield snapshots of protein neighborhoods. Here, we describe a multiscale PLP method with adjustable resolution that uses a commercially available photocatalyst, Eosin Y, which upon visible light illumination activates different photo-probes with a range of labeling radii. We applied this platform to profile neighborhoods of the oncogenic epidermal growth factor receptor and orthogonally validated more than 20 neighbors using immunoassays and AlphaFold-Multimer prediction. We further profiled the protein neighborhoods of cell-cell synapses induced by bispecific T cell engagers and chimeric antigen receptor T cells. This integrated multiscale PLP platform maps local and distal protein networks on and between cell surfaces, which will aid in the systematic construction of the cell surface interactome, revealing horizontal signaling partners and reveal new immunotherapeutic opportunities.

FPR3 reprograms glycolytic metabolism and stemness in gastric cancer via calcium-NFATc1 pathway

Aerobic glycolysis accelerates tumor proliferation and progression, and inhibitors or drugs targeting abnormal cancer metabolism have been developing. Cancer stem-like cells (CSCs) significantly contribute to tumor initiation, metastasis, therapy resistance, and recurrence. Formyl peptide receptor 3 (FPR3), a member of FPR family, involves in inflammation, tissue repair, and angiogenesis. However, studies in exploring the regulatory mechanisms of aerobic glycolysis and CSCs by FPR3 in gastric cancer (GC) remain unknown. Here, we demonstrated that overexpressed FPR3 suppressed glycolytic capacity and stemness of tumor cells, then inhibited GC cells proliferation. Mechanistically, FPR3 impeded cytoplasmic calcium ion flux and hindered nuclear factor of activated T cells 1 (NFATc1) nuclear translocation, leading to the transcriptional inactivation of NFATc1-binding neurogenic locus notch homolog protein 3 (NOTCH3) promoter, subsequently obstructing NOTCH3 expression and the AKT/mTORC1 signaling pathway, and ultimately downregulating glycolysis. Additionally, NFATc1 directly binds to the sex determining region Y-box 2 (SOX2) promoter and modifies stemness in GC. In conclusion, our work illustrated that FPR3 played a negative role in GC progression by modulating NFATc1-mediated glycolysis and stemness in a calcium-dependent manner, providing potential insights into cancer therapy.

Targeting CD8+ T cells with natural products for tumor therapy: Revealing insights into the mechanisms

BACKGROUND

Despite significant advances in cancer immunotherapy over the past decades, such as T cell-engaging chimeric antigen receptor (CAR)-T cell therapy and immune checkpoint blockade (ICB), therapeutic failure resulting from various factors remains prevalent. Therefore, developing combinational immunotherapeutic strategies is of great significance for improving the clinical outcome of cancer immunotherapy. Natural products are substances that naturally exist in various living organisms with multiple pharmacological or biological activities, and some of them have been found to have anti-tumor potential. Notably, emerging evidences have suggested that several natural compounds may boost the anti-tumor effects through activating immune response of hosts, in which CD8+ T cells play a pivotal role.

METHODS

The data of this review come from PubMed, Web of Science, Google Scholar, and ClinicalTrials (https://clinicaltrials.gov/) with the keywords "CD8+ T cell", "anti-tumor", "immunity", "signal 1", "signal 2", "signal 3", "natural products", "T cell receptor (TCR)", "co-stimulation", "co-inhibition", "immune checkpoint", "inflammatory cytokine", "hesperidin", "ginsenoside", "quercetin", "curcumin", "apigenin", "dendrobium officinale polysaccharides (DOPS)", "luteolin", "shikonin", "licochalcone A", "erianin", "resveratrol", "procyanidin", "berberine", "usnic acid", "naringenin", "6-gingerol", "ganoderma lucidum polysaccharide (GL-PS)", "neem leaf glycoprotein (NLGP)", "paclitaxel", "source", "pharmacological activities", and "toxicity". These literatures were published between 1993 and 2023.

RESULTS

Natural products have considerable advantages as anti-tumor drugs based on the various species, wide distribution, low price, and few side effects. This review summarized the effects and mechanisms of some natural products that exhibit anti-tumor effects via targeting CD8+ T cells, mainly focused on the three signals that activate CD8+ T cells: TCR, co-stimulation, and inflammatory cytokines.

CONCLUSION

Clarifying the role and underlying mechanism of natural products in cancer immunotherapy may provide more options for combinational treatment strategies and benefit cancer therapy, to shed light on identifying potential natural compounds for improving the clinical outcome in cancer immunotherapy.

Coencapsulation of Immunosuppressive Drug with Anti-Inflammatory Molecule in Pickering Emulsions as an Innovative Therapeutic Approach for Inflammatory Dermatoses

Psoriasis is an inflammatory skin disease characterized by epidermal and immune dysfunctions. Although efficient, current topical treatments display adverse effects, including skin atrophy and burning sensation, leading to poor patient adherence. To overcome these downsides, pickering emulsions were formulated in which the calcitriol-containing dispersed phase was stabilized with either cyclosporin A- or tacrolimus-loaded poly(lactic-co-glycolic) acid nanoparticles. This study aimed to investigate their biological effects on lymphocytes and epidermal cells and their effectiveness in an imiquimod-induced psoriasis-like mouse model. Results showed that both emulsions significantly inhibited nuclear factor of activated T cell translocation in T lymphocytes as well as their IL-2 production, cell activation, and proliferation. In keratinocytes, inhibition of nuclear factor of activated T cell translocation decreased the production of IL-8 and TNF-α. Topical application of emulsions over skin biopsies ex vivo showed accumulation of rhodamin B-coupled poly(lactic-co-glycolic) acid nanoparticles throughout the epidermis by immunofluorescence and significantly decreased the antigen-presenting capacity of Langerhans cells in relation to a reduced expression of activation markers CD40, CD86, and HLA-DR. Using an imiquimod-induced psoriasis model in vivo, pickering emulsions significantly alleviated psoriasiform lesions potentially attributed to the decreased cutaneous expression of T-cell markers, proinflammatory cytokines, chemokines, and specific epidermal cell genes. Altogether, pickering emulsion might be a very efficient formulation for treating inflammatory dermatoses.

AS101 regulates the Teff/Treg balance to alleviate rabbit autoimmune dacryoadenitis through modulating NFATc2

Sjögren's syndrome (SS) dry eye can cause ocular surface inflammation and lacrimal gland (LG) damage, leading to discomfort and potential vision problems. The existing treatment options for SS dry eye are currently constrained. We investigated the possible therapeutic effect and the underlying mechanism of AS101 in autoimmune dry eye. AS101 was injected subconjunctivally into a rabbit model of autoimmune dacryoadenitis and its therapeutic effects were determined by evaluating clinical and histological scores. The expressions of effector T cells (Teff)/regulatory T cells (Treg)-related transcription factors and cytokines, inflammation mediators, and transcription factor NFATc2 were measured by quantitative real-time PCR and/or Western blot both in vivo and in vitro. Additionally, the role of NFATc2 in the immunomodulatory effects of AS101 on T cells was explored by co-culturing activated peripheral blood lymphocytes (PBLs) transfected with NFATc2 overexpression lentiviral plasmid with AS101. AS101 treatment potently ameliorated the clinical severity and reduced the inflammation of LG. Further investigation revealed that AS101 treatment led to decreased expression of Th1-related genes (T-bet and IFN-γ) and Th17-related genes (RORC, IL-17A, IL-17F, and GM-CSF) and increased expression of Treg-related gene Foxp3 in vivo and in vitro. Meanwhile, AS101 suppressed the expression of TNF-α, IL-1β, IL-23, IL-6, MMP-2, and MMP-9. Mechanistically, AS101 downregulated the expression of NFATc2 in inflamed LGs. Overexpression of NFATc2 in activated PBLs partially blunted the effect of AS101 on Teff suppression and Treg promotion. In conclusion, AS101 is a potential regulator of Teff/Treg cell balance and could be an effective treatment agent for SS dry eye.

Strategies for the development of metalloimmunotherapies

Metal ions play crucial roles in the regulation of immune pathways. In fact, metallodrugs have a long record of accomplishment as effective treatments for a wide range of diseases. Here we argue that the modulation of interactions of metal ions with molecules and cells involved in the immune system forms the basis of a new class of immunotherapies. By examining how metal ions modulate the innate and adaptive immune systems, as well as host-microbiota interactions, we discuss strategies for the development of such metalloimmunotherapies for the treatment of cancer and other immune-related diseases.

HNRNPA2B1 stabilizes NFATC3 levels to potentiate its combined actions with FOSL1 to mediate vasculogenic mimicry in GBM cells

BACKGROUND

Vasculogenic mimicry (VM) is an enigmatic physiological feature that influences blood supply within glioblastoma (GBM) tumors for their sustained growth. Previous studies identify NFATC3, FOSL1 and HNRNPA2B1 as significant mediators of VEGFR2, a key player in vasculogenesis, and their molecular relationships may be crucial for VM in GBM.

AIMS

The aim of this study was to understand how NFATC3, FOSL1 and HNRNPA2B1 collectively influence VM in GBM.

METHODS

We have investigated the underlying gene regulatory mechanisms for VM in GBM cell lines U251 and U373 in vitro and in vivo. In vitro cell-based assays were performed to explore the role of NFATC3, FOSL1 and HNRNPA2B1 in GBM cell proliferation, VM and migration, in the context of RNA interference (RNAi)-mediated knockdown alongside corresponding controls. Western blotting and qRT-PCR assays were used to examine VEGFR2 expression levels. CO-IP was employed to detect protein-protein interactions, ChIP was used to detect DNA-protein complexes, and RIP was used to detect RNA-protein complexes. Histochemical staining was used to detect VM tube formation in vivo.

RESULTS

Focusing on NFATC3, FOSL1 and HNRNPA2B1, we found each was significantly upregulated in GBM and positively correlated with VM-like cellular behaviors in U251 and U373 cell lines. Knockdown of NFATC3, FOSL1 or HNRNPA2B1 each resulted in decreased levels of VEGFR2, a key growth factor gene that drives VM, as well as the inhibition of proliferation, cell migration and extracorporeal VM activity. Chromatin immunoprecipitation (ChIP) studies and luciferase reporter gene assays revealed that NFATC3 binds to the promoter region of VEGFR2 to enhance VEGFR2 gene expression. Notably, FOSL1 interacts with NFATC3 as a co-factor to potentiate the DNA-binding capacity of NFATC3, resulting in enhanced VM-like cellular behaviors. Also, level of NFATC3 protein in cells was enhanced through HNRNPA2B1 binding of NFATC3 mRNA. Furthermore, RNAi-mediated silencing of NFATC3, FOSL1 and HNRNPA2B1 in GBM cells reduced their capacity for tumor formation and VM-like behaviors in vivo.

CONCLUSION

Taken together, our findings identify NFATC3 as an important mediator of GBM tumor growth through its molecular and epistatic interactions with HNRNPA2B1 and FOSL1 to influence VEGFR2 expression and VM-like cellular behaviors.

Engineering CD3/CD137 Dual Specificity into a DLL3-Targeted T-Cell Engager Enhances T-Cell Infiltration and Efficacy against Small-Cell Lung Cancer

Small-cell lung cancer (SCLC) is an aggressive cancer for which immune checkpoint inhibitors (ICI) have had only limited success. Bispecific T-cell engagers are promising therapeutic alternatives for ICI-resistant tumors, but not all patients with SCLC are responsive. Herein, to integrate CD137 costimulatory function into a T-cell engager format and thereby augment therapeutic efficacy, we generated a CD3/CD137 dual-specific Fab and engineered a DLL3-targeted trispecific antibody (DLL3 trispecific). The CD3/CD137 dual-specific Fab was generated to competitively bind to CD3 and CD137 to prevent DLL3-independent cross-linking of CD3 and CD137, which could lead to systemic T-cell activation. We demonstrated that DLL3 trispecific induced better tumor growth control and a marked increase in the number of intratumoral T cells compared with a conventional DLL3-targeted bispecific T-cell engager. These findings suggest that DLL3 trispecific can exert potent efficacy by inducing concurrent CD137 costimulation and provide a promising therapeutic option for SCLC.

Tanshinone IIA induces ER stress and JNK activation to inhibit tumor growth and enhance anti-PD-1 immunotherapy in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) remains at the forefront of new cancer cases, and there is an urgent need to find new treatments or improve the efficacy of existing therapies. In addition to the application in the field of cerebrovascular diseases, recent studies have revealed that tanshinone IIA (Tan IIA) has anticancer activity in a variety of cancers.

PURPOSE

To investigate the potential anticancer mechanism of Tan IIA and its impact on immunotherapy in NSCLC.

METHODS

Cytotoxicity and colony formation assays were used to detect the Tan IIA inhibitory effect on NSCLC cells. This research clarified the mechanisms of Tan IIA in anti-tumor and programmed death-ligand 1 (PD-L1) regulation by using flow cytometry, transient transfection, western blotting and immunohistochemistry (IHC) methods. Besides, IHC was also used to analyze the nuclear factor of activated T cells 1 (NFAT2) expression in NSCLC clinical samples. Two animal models including xenograft mouse model and Lewis lung cancer model were used for evaluating tumor suppressive efficacy of Tan IIA. We also tested the efficacy of Tan IIA combined with programmed cell death protein 1 (PD-1) inhibitors in Lewis lung cancer model.

RESULTS

Tan IIA exhibited good NSCLC inhibitory effect which was accompanied by endoplasmic reticulum (ER) stress response and increasing Ca2+ levels. Moreover, Tan IIA could suppress the NFAT2/ Myc proto oncogene protein (c-Myc) signaling, and it also was able to control the Jun Proto-Oncogene(c-Jun)/PD-L1 axis in NSCLC cells through the c-Jun N-terminal kinase (JNK) pathway. High NFAT2 levels were potential factors for poor prognosis in NSCLC patients. Finally, animal experiments data showed a stronger immune activation phenotype, when we performed treatment of Tan IIA combined with PD-1 monoclonal antibody.

CONCLUSION

The findings of our research suggested a novel mechanism for Tan IIA to inhibit NSCLC, which could exert anti-cancer effects through the JNK/NFAT2/c-Myc pathway. Furthermore, Tan IIA could regulate tumor PD-L1 levels and has the potential to improve the efficacy of PD-1 inhibitors.

Ligandability assessment of the C-terminal Rel-homology domain of NFAT1

Transcription factors are generally considered challenging, if not "undruggable", targets but they promise new therapeutic options due to their fundamental involvement in many diseases. In this study, we aim to assess the ligandability of the C-terminal Rel-homology domain of nuclear factor of activated T cells 1 (NFAT1), a TF implicated in T-cell regulation. Using a combination of experimental and computational approaches, we demonstrate that small molecule fragments can indeed bind to this protein domain. The newly identified binder is the first small molecule binder to NFAT1 validated with biophysical methods and an elucidated binding mode by X-ray crystallography. The reported eutomer/distomer pair provides a strong basis for potential exploration of higher potency binders on the path toward degrader or glue modalities.

Dysregulated Wnt and NFAT signaling in a Parkinson's disease LRRK2 G2019S knock-in model

Parkinson's disease (PD) is a progressive late-onset neurodegenerative disease leading to physical and cognitive decline. Mutations of leucine-rich repeat kinase 2 (LRRK2) are the most common genetic cause of PD. LRRK2 is a complex scaffolding protein with known regulatory roles in multiple molecular pathways. Two prominent examples of LRRK2-modulated pathways are Wingless/Int (Wnt) and nuclear factor of activated T-cells (NFAT) signaling. Both are well described key regulators of immune and nervous system development as well as maturation. The aim of this study was to establish the physiological and pathogenic role of LRRK2 in Wnt and NFAT signaling in the brain, as well as the potential contribution of the non-canonical Wnt/Calcium pathway. In vivo cerebral Wnt and NFATc1 signaling activity was quantified in LRRK2 G2019S mutant knock-in (KI) and LRRK2 knockout (KO) male and female mice with repeated measures over 28 weeks, employing lentiviral luciferase biosensors, and analyzed using a mixed-effect model. To establish spatial resolution, we investigated tissues, and primary neuronal cell cultures from different brain regions combining luciferase signaling activity, immunohistochemistry, qPCR and western blot assays. Results were analyzed by unpaired t-test with Welch's correction or 2-way ANOVA with post hoc corrections. In vivo Wnt signaling activity in LRRK2 KO and LRRK2 G2019S KI mice was increased significantly ~ threefold, with a more pronounced effect in males (~ fourfold) than females (~ twofold). NFATc1 signaling was reduced ~ 0.5-fold in LRRK2 G2019S KI mice. Brain tissue analysis showed region-specific expression changes in Wnt and NFAT signaling components. These effects were predominantly observed at the protein level in the striatum and cerebral cortex of LRRK2 KI mice. Primary neuronal cell culture analysis showed significant genotype-dependent alterations in Wnt and NFATc1 signaling under basal and stimulated conditions. Wnt and NFATc1 signaling was primarily dysregulated in cortical and hippocampal neurons respectively. Our study further built on knowledge of LRRK2 as a Wnt and NFAT signaling protein. We identified complex changes in neuronal models of LRRK2 PD, suggesting a role for mutant LRRK2 in the dysregulation of NFAT, and canonical and non-canonical Wnt signaling.

Elevated levels of IL-12/IL-23p40 in Nova Scotia Duck Tolling Retrievers with autoimmune disease and lymphoma

The Nova Scotia Duck Tolling Retriever (NSDTR) is predisposed to immune mediated rheumatic disease (IMRD), steroid-responsive meningitis-arteritis (SRMA) and certain forms of cancer. Cytokines are the main regulators of the immune system. Interleukin 2 is a cytokine involved in activation of T regulatory cells, playing a role in central tolerance and tumor immunity. Interleukin 12 and interleukin 23 share the same subunit, p40, and are both pro-inflammatory cytokines. The aim of this study was to compare levels of IL-2 in healthy NSDTRs to those with cancer or autoimmune disease and to compare levels of IL-12/IL-23p40 in healthy NSDTRs and beagles versus NSDTRs with cancer or autoimmune disease. 62 dogs were included in the analysis of IL-12/IL-23p40; healthy NSDTRs (n = 16), healthy beagles (n = 16), NSDTRs autoimmune (n = 18) and NDSTRs lymphoma/mastocytoma (n = 12) and 68 dogs for IL-2; healthy (n = 20), autoimmune (n = 36) and lymphoma/mastocytoma/adenocarcinoma (n = 12). NSDTRs with autoimmune disease had higher levels of IL-12/IL-23p40 compared to healthy dogs (p = 0.008). NSDTRs with lymphoma also had higher levels of IL-12/IL-23p40 compared to healthy NSDTRs (p = 0.002). There was no difference in levels of IL-2 between healthy and diseased NSDTR. Statistical analysis was performed using Bonferroni corrections for multiple testing. These findings can contribute to the knowledge of autoimmune disease and cancer in dogs.

Human T-cell lymphotropic virus type 1 (HTLV-1) grip on T-cells: investigating the viral tapestry of activation

INTRODUCTION

Human T-cell Lymphotropic virus type 1 (HTLV-1) belongs to retroviridae which is connected to two major diseases, including HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and Adult T-cell leukemia/lymphoma (ATLL). This study aims to investigate the mRNA expressions of key proteins correlated to T-cell activation in asymptomatic carriers (ACs) HTLV-1 infected patients, shedding light on early molecular events and T-cell activation following HTLV-1 infection.

MATERIAL AND METHODS

The study involved 40 participants, including 20 ACs and 20 healthy subjects. Blood samples were collected, ELISA assessment for screening and confirmation with PCR for Trans-activating transcriptional regulatory protein (Tax) and HTLV-1 basic leucine zipper factor (HBZ) of the HTLV-1 were done. mRNA expressions of C-terminal Src kinase (CSK), Glycogen Synthase Kinase-3 Beta (GSK3β), Mitogen-Activated Protein Kinase 14 (MAP3K14 or NIK), Phospholipase C Gamma-1 (PLCG1), Protein Tyrosine Phosphatase non-Receptor Type 6 (PTPN6) and Mitogen-Activated Protein Kinase Kinase Kinase-7 (SLP-76) and Mitogen-Activated Protein Kinase14 (MAP3K7 or TAK1) were assayed using RT-qPCR. Statistical analyses were performed using PRISM and SPSS software.

RESULTS

While there were no significant upregulation in CSK and PTPN6 in ACs compared to healthy individuals, expression levels of GSK3β, MAP3K14, PLCG1, SLP-76, and TAK1 were significantly higher in ACs compared to healthy subjects which directly contributes to T-cell activation in the HTLV-1 ACs.

CONCLUSION

HTLV-1 infection induces differential mRNA expressions in key proteins associated with T-cell activation. mRNAs related to T-cell activation showed significant upregulation compared to PTPN6 and CSK which contributed to T-cell regulation. Understanding these early molecular events in ACs may provide potential markers for disease progression and identify therapeutic targets for controlling viral replication and mitigating associated diseases. The study contributes novel insights to the limited literature on T-cell activation and HTLV-1 pathogenesis.

Transcription factors in chimeric antigen receptor T-cell development

Chimeric antigen receptor (CAR) T-cell therapy is a new and innovative approach to treating cancers that has shown promising results in the treatment of lymphoma. However, it has been found to be less effective in the treatment of solid tumors. To overcome the limitation, researchers have explored the use of combined CAR-T therapy with other complementary regimens that target specific genes or biomarkers, which would enhance the synergistic therapeutic effects. Transcription factors (TFs) have been identified as potential markers that can regulate gene expression in CAR-T cells to enhance their cytotoxicity and safety. TFs are known to bind DNA specifically and recruit cofactor proteins to regulate the expression of target genes. By targeting TFs, it is possible to improve the anti-tumor response of CAR-T cells by altering their phenotype and transcriptional map, thereby increasing their effector function, such as reducing the exhaustion, enhancing the survival, and cytotoxicity of CAR-T cells. This review summarizes the application of transcription factors in CART therapy to enhance the synergistic therapeutic effect of CAR-T cells in the treatment of solid tumors and improve their anti-tumor responses.

NFATc4 Knockout Promotes Neuroprotection and Retinal Ganglion Cell Regeneration After Optic Nerve Injury

Retinal ganglion cells (RGCs), neurons transmitting visual information via the optic nerve, fail to regenerate their axons after injury. The progressive loss of RGC function underlies the pathophysiology of glaucoma and other optic neuropathies, often leading to irreversible blindness. Therefore, there is an urgent need to identify the regulators of RGC survival and the regenerative program. In this study, we investigated the role of the family of transcription factors known as nuclear factor of activated T cells (NFAT), which are expressed in the retina; however, their role in RGC survival after injury is unknown. Using the optic nerve crush (ONC) model, widely employed to study optic neuropathies and central nervous system axon injury, we found that NFATc4 is specifically but transiently up-regulated in response to mechanical injury. In the injured retina, NFATc4 immunolocalized primarily to the ganglionic cell layer. Utilizing NFATc4-/- and NFATc3-/- mice, we demonstrated that NFATc4, but not NFATc3, knockout increased RGC survival, improved retina function, and delayed axonal degeneration. Microarray screening data, along with decreased immunostaining of cleaved caspase-3, revealed that NFATc4 knockout was protective against ONC-induced degeneration by suppressing pro-apoptotic signaling. Finally, we used lentiviral-mediated NFATc4 delivery to the retina of NFATc4-/- mice and reversed the pro-survival effect of NFATc4 knockout, conclusively linking the enhanced survival of injured RGCs to NFATc4-dependent mechanisms. In summary, this study is the first to demonstrate that NFATc4 knockout may confer transient RGC neuroprotection and decelerate axonal degeneration after injury, providing a potent therapeutic strategy for optic neuropathies.

Microbiota metabolites in bone: Shaping health and Confronting disease

The intricate interplay between the gut microbiota and bone health has become increasingly recognized as a fundamental determinant of skeletal well-being. Microbiota-derived metabolites play a crucial role in dynamic interaction, specifically in bone homeostasis. In this sense, short-chain fatty acids (SCFAs), including acetate, propionate, and butyrate, indirectly promote bone formation by regulating insulin-like growth factor-1 (IGF-1). Trimethylamine N-oxide (TMAO) has been found to increase the expression of osteoblast genes, such as Runt-related transcription factor 2 (RUNX2) and bone morphogenetic protein-2 (BMP2), thus enhancing osteogenic differentiation and bone quality through BMP/SMADs and Wnt signaling pathways. Remarkably, in the context of bone infections, the role of microbiota metabolites in immune modulation and host defense mechanisms potentially affects susceptibility to infections such as osteomyelitis. Furthermore, ongoing research elucidates the precise mechanisms through which microbiota-derived metabolites influence bone cells, such as osteoblasts and osteoclasts. Understanding the multifaceted influence of microbiota metabolites on bone, from regulating homeostasis to modulating susceptibility to infections, has the potential to revolutionize our approach to bone health and disease management. This review offers a comprehensive exploration of this evolving field, providing a holistic perspective on the impact of microbiota metabolites on bone health and diseases.

Bile acids modified by the intestinal microbiota promote colorectal cancer growth by suppressing CD8+ T cell effector functions

Concentrations of the secondary bile acid, deoxycholic acid (DCA), are aberrantly elevated in colorectal cancer (CRC) patients, but the consequences remain poorly understood. Here, we screened a library of gut microbiota-derived metabolites and identified DCA as a negative regulator for CD8+ T cell effector function. Mechanistically, DCA suppressed CD8+ T cell responses by targeting plasma membrane Ca2+ ATPase (PMCA) to inhibit Ca2+-nuclear factor of activated T cells (NFAT)2 signaling. In CRC patients, CD8+ T cell effector function negatively correlated with both DCA concentration and expression of a bacterial DCA biosynthetic gene. Bacteria harboring DCA biosynthetic genes suppressed CD8+ T cells effector function and promoted tumor growth in mice. This effect was abolished by disrupting bile acid metabolism via bile acid chelation, genetic ablation of bacterial DCA biosynthetic pathway, or specific bacteriophage. Our study demonstrated causation between microbial DCA metabolism and anti-tumor CD8+ T cell response in CRC, suggesting potential directions for anti-tumor therapy.

The NFATc1/P2X7 receptor relationship in human intervertebral disc cells

A comprehensive understanding of the molecules that play key roles in the physiological and pathological homeostasis of the human intervertebral disc (IVD) remains challenging, as does the development of new therapeutic treatments. We recently found a positive correlation between IVD degeneration (IDD) and P2X7 receptor (P2X7R) expression increases both in the cytoplasm and in the nucleus. Using immunocytochemistry, reverse transcription PCR (RT-PCR), overexpression, and chromatin immunoprecipitation, we found that NFATc1 and hypoxia-inducible factor-1α (HIF-1α) are critical regulators of P2X7R. Both transcription factors are recruited at the promoter of the P2RX7 gene and involved in its positive and negative regulation, respectively. Furthermore, using the proximity ligation assay, we revealed that P2X7R and NFATc1 form a molecular complex and that P2X7R is closely associated with lamin A/C, a major component of the nuclear lamina. Collectively, our study identifies, for the first time, P2X7R and NFATc1 as markers of IVD degeneration and demonstrates that both NFATc1 and lamin A/C are interaction partners of P2X7R.

Targeting the chromatin binding of exportin-1 disrupts NFAT and T cell activation

Exportin-1 (XPO1/CRM1) plays a central role in the nuclear-to-cytoplasmic transport of hundreds of proteins and contributes to other cellular processes, such as centrosome duplication. Small molecules targeting XPO1 induce cytotoxicity, and selinexor was approved by the Food and Drug Administration in 2019 as a cancer chemotherapy for relapsed multiple myeloma. Here, we describe a cell-type-dependent chromatin-binding function for XPO1 that is essential for the chromatin occupancy of NFAT transcription factors and thus the appropriate activation of T cells. Additionally, we establish a class of XPO1-targeting small molecules capable of disrupting the chromatin binding of XPO1 without perturbing nuclear export or inducing cytotoxicity. This work defines a broad transcription regulatory role for XPO1 that is essential for T cell activation as well as a new class of XPO1 modulators to enable therapeutic targeting of XPO1 beyond oncology including in T cell-driven autoimmune disorders.

Single-cell RNA sequencing reveals Immune Education promotes T cell survival in mice subjected to the cecal ligation and puncture sepsis model

Background

Individual T cell responses vary significantly based on the microenvironment present at the time of immune response and on prior induced T cell memory. While the cecal ligation and puncture (CLP) model is the most commonly used murine sepsis model, the contribution of diverse T cell responses has not been explored. We defined T cell subset responses to CLP using single-cell RNA sequencing and examined the effects of prior induced T cell memory (Immune Education) on these responses. We hypothesized that Immune Education prior to CLP would alter T cell responses at the single cell level at a single, early post-CLP time point.

Methods

Splenic T cells were isolated from C57BL/6 mice. Four cohorts were studied: Control, Immune-Educated, CLP, and Immune-Educated CLP. At age 8 weeks, Immune-Educated and Immune-Educated CLP mice received anti-CD3ϵ antibody; Control and CLP mice were administered an isotype control. CLP (two punctures with a 22-gauge needle) was performed at 12-13 weeks of life. Mice were sacrificed at baseline or 24-hours post-CLP. Unsupervised clustering of the transcriptome library identified six distinct T cell subsets: quiescent naïve CD4+, primed naïve CD4+, memory CD4+, naïve CD8+, activated CD8+, and CD8+ cytotoxic T cell subsets. T cell subset specific gene set enrichment analysis and Hurdle analysis for differentially expressed genes (DEGs) were performed.

Results

T cell responses to CLP were not uniform - subsets of activated and suppressed T cells were identified. Immune Education augmented specific T cell subsets and led to genomic signatures favoring T cell survival in unoperated and CLP mice. Additionally, the combination of Immune Education and CLP effected the expression of genes related to T cell activity in ways that differed from CLP alone. Validating our finding that IL7R pathway markers were upregulated in Immune-Educated CLP mice, we found that Immune Education increased T cell surface IL7R expression in post-CLP mice.

Conclusion

Immune Education enhanced the expression of genes associated with T cell survival in unoperated and CLP mice. Induction of memory T cell compartments via Immune Education combined with CLP may increase the model's concordance to human sepsis.

Genetic associations with ratios between protein levels detect new pQTLs and reveal protein-protein interactions

Protein quantitative trait loci (pQTLs) are an invaluable source of information for drug target development because they provide genetic evidence to support protein function, suggest relationships between cis- and trans-associated proteins, and link proteins to disease endpoints. Using Olink proteomics data for 1,463 proteins measured in over 54,000 samples of the UK Biobank, we identified 4,248 associations with 2,821 ratios between protein levels (rQTLs). rQTLs were 7.6-fold enriched in known protein-protein interactions, suggesting that their ratios reflect biological links between the implicated proteins. Conducting a GWAS on ratios increased the number of discovered genetic signals by 24.7%. The approach can identify novel loci of clinical relevance, support causal gene identification, and reveal complex networks of interacting proteins. Taken together, our study adds significant value to the genetic insights that can be derived from the UKB proteomics data and motivates the wider use of ratios in large-scale GWAS.

Synthetic Biology Meets Ca2+ Release-Activated Ca2+ Channel-Dependent Immunomodulation

Many essential biological processes are triggered by the proximity of molecules. Meanwhile, diverse approaches in synthetic biology, such as new biological parts or engineered cells, have opened up avenues to precisely control the proximity of molecules and eventually downstream signaling processes. This also applies to a main Ca2+ entry pathway into the cell, the so-called Ca2+ release-activated Ca2+ (CRAC) channel. CRAC channels are among other channels are essential in the immune response and are activated by receptor-ligand binding at the cell membrane. The latter initiates a signaling cascade within the cell, which finally triggers the coupling of the two key molecular components of the CRAC channel, namely the stromal interaction molecule, STIM, in the ER membrane and the plasma membrane Ca2+ ion channel, Orai. Ca2+ entry, established via STIM/Orai coupling, is essential for various immune cell functions, including cytokine release, proliferation, and cytotoxicity. In this review, we summarize the tools of synthetic biology that have been used so far to achieve precise control over the CRAC channel pathway and thus over downstream signaling events related to the immune response.

Tumor-Intrinsic Galectin-3 Suppresses Melanoma Metastasis

Melanoma poses a poor prognosis with high mortality rates upon metastasis. Exploring the molecular mechanisms governing melanoma progression paves the way for developing novel approaches to control melanoma metastasis and ultimately enhance patient survival rates. Extracellular galectin-3 (Gal-3) has emerged as a pleiotropic promoter of melanoma metastasis, exerting varying activities depending on its interacting partner. However, whether intracellular Gal-3 promotes melanoma aggressive behavior remains unknown. In this study, we explored Gal-3 expression in human melanoma tissues as well as in murine melanoma models to examine its causal role in metastatic behavior. We found that Gal-3 expression is downregulated in metastatic melanoma tissues compared with its levels in primary melanomas. Enforced silencing of Gal-3 in melanoma cells promoted migration, invasion, colony formation, in vivo xenograft growth, and metastasis and activated canonical oncogenic signaling pathways. Moreover, loss of Gal-3 in melanoma cells resulted in upregulated the expression of the prometastatic transcription factor NFAT1 and its downstream metastasis-associated proteins, matrix metalloproteinase 3, and IL-8. Overall, our findings implicate melanoma intracellular Gal-3 as a major determinant of its metastatic behavior and reveal a negative regulatory role for Gal-3 on the expression of NFAT1 in melanoma cells.

PTEN loss in glioma cell lines leads to increased extracellular vesicles biogenesis and PD-L1 cargo in a PI3K-dependent manner

Phosphatase and Tensin Homologue (PTEN) is one of the most frequently lost tumor suppressors in cancer and the predominant negative regulator of the PI3K/AKT signaling axis. A growing body of evidence has highlighted the loss of PTEN with immuno-modulatory functions including the upregulation of the programmed death ligand-1 (PD-L1), an altered tumor derived secretome that drives an immunosuppressive tumor immune microenvironment (TIME), and resistance to certain immunotherapies. Given their roles in immunosuppression and tumor growth, we examined whether the loss of PTEN would impact the biogenesis, cargo, and function of extracellular vesicles (EVs) in the context of the anti-tumor associated cytokine interferon-γ (IFN-γ). Through genetic and pharmacological approaches, we show that PD-L1 expression is regulated by JAK/STAT signaling, not PI3K signaling. Instead, we observe that PTEN loss positively upregulates cell surface levels of PD-L1 and enhances the biogenesis of EVs enriched with PD-L1 in a PI3K-dependent manner. We demonstrate that because of these changes, EVs derived from glioma cells lacking PTEN have a greater ability to suppress T cell receptor (TCR) signaling. Taken together, these findings provide important new insights into how the loss of PTEN can contribute to an immunosuppressive TIME, facilitate immune evasion, and highlight a novel role for PI3K signaling in the regulation of EV biogenesis and the cargo they contain.

Recent advances on CAR-T signaling pave the way for prolonged persistence and new modalities in clinic

Chimeric antigen receptor T-cell (CAR-T) therapy has revolutionized the treatment of hematological malignancies. The importance of the receptor costimulatory domain for long-term CAR-T cell engraftment and therapeutic efficacy was demonstrated with second-generation CAR-T cells. Fifth generation CAR-T cells are currently in preclinical trials. At the same time, the processes that orchestrate the activation and differentiation of CAR-T cells into a specific phenotype that predisposes them to long-term persistence are not fully understood. This review highlights ongoing research aimed at elucidating the role of CAR domains and T-cell signaling molecules involved in these processes.

Cell softness renders cytotoxic T lymphocytes and T leukemic cells resistant to perforin-mediated killing

Mechanical force contributes to perforin pore formation at immune synapses, thus facilitating the cytotoxic T lymphocytes (CTL)-mediated killing of tumor cells in a unidirectional fashion. How such mechanical cues affect CTL evasion of perforin-mediated autolysis remains unclear. Here we show that activated CTLs use their softness to evade perforin-mediated autolysis, which, however, is shared by T leukemic cells to evade CTL killing. Downregulation of filamin A is identified to induce softness via ZAP70-mediated YAP Y357 phosphorylation and activation. Despite the requirements of YAP in both cell types for softness induction, CTLs are more resistant to YAP inhibitors than malignant T cells, potentially due to the higher expression of the drug-resistant transporter, MDR1, in CTLs. As a result, moderate inhibition of YAP stiffens malignant T cells but spares CTLs, thus allowing CTLs to cytolyze malignant cells without autolysis. Our findings thus hint a mechanical force-based immunotherapeutic strategy against T cell leukemia.

Time-resolved role of P2X4 and P2X7 during CD8+ T cell activation

CD8+ T cells are a crucial part of the adaptive immune system, responsible for combating intracellular pathogens and tumor cells. The initial activation of T cells involves the formation of highly dynamic Ca2+ microdomains. Recently, purinergic signaling was shown to be involved in the formation of the initial Ca2+ microdomains in CD4+ T cells. In this study, the role of purinergic cation channels, particularly P2X4 and P2X7, in CD8+ T cell signaling from initial events to downstream responses was investigated, focusing on various aspects of T cell activation, including Ca2+ microdomains, global Ca2+ responses, NFAT-1 translocation, cytokine expression, and proliferation. While Ca2+ microdomain formation was significantly reduced in the first milliseconds to seconds in CD8+ T cells lacking P2X4 and P2X7 channels, global Ca2+ responses over minutes were comparable between wild-type (WT) and knockout cells. However, the onset velocity was reduced in P2X4-deficient cells, and P2X4, as well as P2X7-deficient cells, exhibited a delayed response to reach a certain level of free cytosolic Ca2+ concentration ([Ca2+]i). NFAT-1 translocation, a crucial transcription factor in T cell activation, was also impaired in CD8+ T cells lacking P2X4 and P2X7. In addition, the expression of IFN-γ, a major pro-inflammatory cytokine produced by activated CD8+ T cells, and Nur77, a negative regulator of T cell activation, was significantly reduced 18h post-stimulation in the knockout cells. In line, the proliferation of T cells after 3 days was also impaired in the absence of P2X4 and P2X7 channels. In summary, the study demonstrates that purinergic signaling through P2X4 and P2X7 enhances initial Ca2+ events during CD8+ T cell activation and plays a crucial role in regulating downstream responses, including NFAT-1 translocation, cytokine expression, and proliferation on multiple timescales. These findings suggest that targeting purinergic signaling pathways may offer potential therapeutic interventions.

Functional characterization of AF-04, an afucosylated anti-MARV GP antibody

Marburg virus (MARV), one member of the Filoviridae family, cause sporadic outbreaks of hemorrhagic fever with high mortality rates. No countermeasures are currently available for the prevention or treatment of MARV infection. Monoclonal antibodies (mAbs) are promising candidates to display high neutralizing activity against MARV infection in vitro and in vivo. Recently, growing evidence has shown that immune effector function including antibody-dependent cell-mediated cytotoxicity (ADCC) is also required for in vivo efficacy of a panel of antibodies. Glyco-engineered methods are widely utilized to augment ADCC function of mAbs. In this study, we generated a fucose-knockout MARV GP-specific mAb named AF-04 and showed that afucosylation dramatically increased its binding affinity to polymorphic FcγRIIIa (F176/V176) compared with the parental AF-03. Accordingly, AF-04-mediated NK cell activation and NFAT expression downstream of FcγRIIIa in effector cells were also augmented. In conclusion, this work demonstrates that AF-04 represents a novel avenue for the treatment of MARV-caused disease.

Targeting CD38/ ADP-ribosyl cyclase as a novel therapeutic strategy for identification of three potent agonists for leukopenia treatment

Leukopenia is the most common side effect of chemotherapy and radiotherapy. It potentially deteriorates into a life-threatening complication in cancer patients. Despite several agents being approved for clinical administration, there are still high incidences of pathogen-related disease due to a lack of functional immune cells. ADP-ribosyl cyclase of CD38 displays a regulatory effect on leukopoiesis and the immune system. To explore whether the ADP-ribosyl cyclase was a potential therapeutic target of leukopenia. We established a drug screening model based on an ADP-ribosyl cyclase-based pharmacophore generation algorithm and discovered three novel ADP-ribosyl cyclase agonists: ziyuglycoside II (ZGSII), brevifolincarboxylic acid (BA), and 3,4-dihydroxy-5-methoxybenzoic acid (DMA). Then, in vitro experiments demonstrated that these three natural compounds significantly promoted myeloid differentiation and antibacterial activity in NB4 cells. In vivo, experiments confirmed that the compounds also stimulated the recovery of leukocytes in irradiation-induced mice and zebrafish. The mechanism was investigated by network pharmacology, and the top 12 biological processes and the top 20 signaling pathways were obtained by intersecting target genes among ZGSII, BA, DMA, and leukopenia. The potential signaling molecules involved were further explored through experiments. Finally, the ADP-ribosyl cyclase agonists (ZGSII, BA, and DMA) has been found to regenerate microbicidal myeloid cells to effectively ameliorate leukopenia-associated infection by activating CD38/ADP-ribosyl cyclase-Ca2+-NFAT. In summary, this study constructs a drug screening model to discover active compounds against leukopenia, reveals the critical roles of ADP-ribosyl cyclase in promoting myeloid differentiation and the immune response, and provides a promising strategy for the treatment of radiation-induced leukopenia.

Shank3 ameliorates neuronal injury after cerebral ischemia/reperfusion via inhibiting oxidative stress and inflammation

Shank3, a key molecule related to the development and deterioration of autism, has recently been found to downregulate in the murine brain after ischemia/reperfusion (I/R). Despite this discovery, however, its effects on neuronal injury and the mechanism underlying the effects remain to be clarified. To address this, in this study, based on genetically modified mice models, we revealed that the expression of Shank3 showed a time-dependent change in murine hippocampal neurons after I/R, and that conditional knockout (cko) of Shank3 in neurons resulted in aggravated neuronal injuries. The protective effects of Shank3 against oxidative stress and inflammation after I/R were achieved through direct binding STIM1 and subsequent proteasome-mediated degradation of STIM1. The STIM1 downregulation induced the phosphorylation of downstream Nrf2 Ser40, which subsequently translocated to the nucleus, and further increased the expression of antioxidant genes such as NQO1 and HO-1 in HT22 cells. In vivo, the study has further confirmed that double knockout of Shank3 and Stim1 alleviated oxidative stress and inflammation after I/R in Shank3cko mice. In conclusion, the present study has demonstrated that Shank3 interacts with STIM1 and inhibits post-I/R neuronal oxidative stress and inflammatory response via the Nrf2 pathway. This interaction can potentially contribute to the development of a promising method for I/R treatment.

The induction of SHP-1 degradation by TAOK3 ensures the responsiveness of T cells to TCR stimulation

Thousand-and-one-amino acid kinase 3 (TAOK3) is a serine and threonine kinase that belongs to the STE-20 family of kinases. Its absence reduces T cell receptor (TCR) signaling and increases the interaction of the tyrosine phosphatase SHP-1, a major negative regulator of proximal TCR signaling, with the kinase LCK, a component of the core TCR signaling complex. Here, we used mouse models and human cell lines to investigate the mechanism by which TAOK3 limits the interaction of SHP-1 with LCK. The loss of TAOK3 decreased the survival of naïve CD4+ T cells by dampening the transmission of tonic and ligand-dependent TCR signaling. In mouse T cells, Taok3 promoted the secretion of interleukin-2 (IL-2) in response to TCR activation in a manner that depended on Taok3 gene dosage and on Taok3 kinase activity. TCR desensitization in Taok3-/- T cells was caused by an increased abundance of Shp-1, and pharmacological inhibition of Shp-1 rescued the activation potential of these T cells. TAOK3 phosphorylated threonine-394 in the phosphatase domain of SHP-1, which promoted its ubiquitylation and proteasomal degradation. The loss of TAOK3 had no effect on the abundance of SHP-2, which lacks a residue corresponding to SHP-1 threonine-394. Modulation of SHP-1 abundance by TAOK3 thus serves as a rheostat for TCR signaling and determines the activation threshold of T lymphocytes.

Cellular Immunobiology and Molecular Mechanisms in Alloimmunity-Pathways of Immunosuppression

Current maintenance immunosuppression commonly comprises a synergistic combination of tacrolimus as calcineurin inhibitor (CNI), mycophenolic acid, and glucocorticoids. Therapy is often individualized by steroid withdrawal or addition of belatacept or inhibitors of the mechanistic target of rapamycin. This review provides a comprehensive overview of their mode of action, focusing on the cellular immune system. The main pharmacological action of CNIs is suppression of the interleukin-2 pathway that leads to inhibition of T cell activation. Mycophenolic acid inhibits the purine pathway and subsequently diminishes T and B cell proliferation but also exerts a variety of effects on almost all immune cells, including inhibition of plasma cell activity. Glucocorticoids exert complex regulation via genomic and nongenomic mechanisms, acting mainly by downregulating proinflammatory cytokine signatures and cell signaling. Belatacept is potent in inhibiting B/T cell interaction, preventing formation of antibodies; however, it lacks the potency of CNIs in preventing T cell-mediated rejections. Mechanistic target of rapamycin inhibitors have strong antiproliferative activity on all cell types interfering with multiple metabolic pathways, partly explaining poor tolerability, whereas their superior effector T cell function might explain their benefits in the case of viral infections. Over the past decades, clinical and experimental studies provided a good overview on the underlying mechanisms of immunosuppressants. However, more data are needed to delineate the interaction between innate and adaptive immunity to better achieve tolerance and control of rejection. A better and more comprehensive understanding of the mechanistic reasons for failure of immunosuppressants, including individual risk/benefit assessments, may permit improved patient stratification.

Genetic deficiency of the transcription factor NFAT1 confers protection against fibrogenic responses independent of immune influx

Idiopathic pulmonary fibrosis (IPF) is marked by unremitting matrix deposition and architectural distortion. Multiple profibrotic pathways contribute to the persistent activation of mesenchymal cells (MCs) in fibrosis, highlighting the need to identify and target common signaling pathways. The transcription factor nuclear factor of activated T cells 1 (NFAT1) lies downstream of second messenger calcium signaling and has been recently shown to regulate key profibrotic mediator autotaxin (ATX) in lung MCs. Herein, we investigate the role of NFAT1 in regulating fibroproliferative responses during the development of lung fibrosis. Nfat1-/--deficient mice subjected to bleomycin injury demonstrated improved survival and protection from lung fibrosis and collagen deposition as compared with bleomycin-injured wild-type (WT) mice. Chimera mice, generated by reconstituting bone marrow cells from WT or Nfat1-/- mice into irradiated WT mice (WT→WT and Nfat1-/-→WT), demonstrated no difference in bleomycin-induced fibrosis, suggesting immune influx-independent fibroprotection in Nfat1-/- mice. Examination of lung tissue and flow sorted lineageneg/platelet-derived growth factor receptor alpha (PDGFRα)pos MCs demonstrated decreased MC numbers, proliferation [↓ cyclin D1 and 5-ethynyl-2'-deoxyuridine (EdU) incorporation], myofibroblast differentiation [↓ α-smooth muscle actin (α-SMA)], and survival (↓ Birc5) in Nfat1-/- mice. Nfat1 deficiency abrogated ATX expression in response to bleomycin in vivo and MCs derived from Nfat1-/- mice demonstrated decreased ATX expression and migration in vitro. Human IPF MCs demonstrated constitutive NFAT1 activation, and regulation of ATX in these cells by NFAT1 was confirmed using pharmacological and genetic inhibition. Our findings identify NFAT1 as a critical mediator of profibrotic processes, contributing to dysregulated lung remodeling and suggest its targeting in MCs as a potential therapeutic strategy in IPF.NEW & NOTEWORTHY Idiopathic pulmonary fibrosis (IPF) is a fatal disease with hallmarks of fibroblastic foci and exuberant matrix deposition, unknown etiology, and ineffective therapies. Several profibrotic/proinflammatory pathways are implicated in accelerating tissue remodeling toward a honeycombed end-stage disease. NFAT1 is a transcriptional factor activated in IPF tissues. Nfat1-deficient mice subjected to chronic injury are protected against fibrosis independent of immune influxes, with suppression of profibrotic mesenchymal phenotypes including proliferation, differentiation, resistance to apoptosis, and autotaxin-related migration.

The mechanism of the NFAT transcription factor family involved in oxidative stress response

As a transcriptional activator widely expressed in various tissues, nuclear factor of activated T cells (NFAT) is involved in the regulation of the immune system, the development of the heart and brain systems, and classically mediating pathological processes such as cardiac hypertrophy. Oxidative stress is an imbalance of intracellular redox status, characterized by excessive generation of reactive oxygen species, accompanied by mitochondrial dysfunction, calcium overload, and subsequent lipid peroxidation, inflammation, and apoptosis. Oxidative stress occurs during various pathological processes, such as chronic hypoxia, vascular smooth muscle cell phenotype switching, ischemia-reperfusion, and cardiac remodeling. Calcium overload leads to an increase in intracellular calcium concentration, while NFAT can be activated through calcium-calcineurin, which is also the main regulatory mode of NFAT factors. This review focuses on the effects of NFAT transcription factors on reactive oxygen species production, calcium overload, mitochondrial dysfunction, redox reactions, lipid peroxidation, inflammation, and apoptosis in response to oxidative stress. We hope to provide a reference for the functions and characteristics of NFAT involved in various stages of oxidative stress as well as related potential targets.

The Impact of Spironolactone Co-administration on Cyclosporin Initial Dosage Optimization for Pediatric Refractory Nephrotic Syndrome

OBJECTIVES

Cyclosporin has been used for the treatment of pediatric refractory nephrotic syndrome (PRNS). However, the narrow therapeutic window and large pharmacokinetic variability make it difficult to individualize cyclosporin administration. Meanwhile, spironolactone has been reported to affect cyclosporin metabolism in PRNS patients. This study aims to explore the initial dosage optimization of cyclosporin in PRNS based on the impact of spironolactone co-administration.

METHODS

Monte Carlo simulation based on a previously established cyclosporin population pharmacokinetic model for PRNS was used to design cyclosporin dosing regimen.

RESULTS

In this study, the probability of drug concentration reaching the target and the convenience of times of administration were considered comprehensively. The optimal administration regimen in PRNS without spironolactone was 6, 5, 4 and 3 mg/kg cyclosporin split into two doses for the body weight of 5-8, 8-18, 18-46 and 46-70 kg, respectively. The optimal administration regimen in PRNS with spironolactone was 4, 3, 2 mg/kg cyclosporin split into two doses for body weight of 5-14, 14-65, and 65-70 kg, respectively.

CONCLUSION

The cyclosporin dosing regimen for PRNS based on Monte Carlo simulation was systematically developed and the initial dosage optimization of cyclosporin in PRNS was recommended for the first time.

The role of Ca2+-signaling in the regulation of epigenetic mechanisms

Epigenetic mechanisms regulate multiple cell functions like gene expression and chromatin conformation and stability, and its misregulation could lead to several diseases including cancer. Epigenetic drugs are currently under investigation in a broad range of diseases, but the cellular processes involved in regulating epigenetic mechanisms are not fully understood. Calcium (Ca2+) signaling regulates several cellular mechanisms such as proliferation, gene expression, and metabolism, among others. Moreover, Ca2+ signaling is also involved in diseases such as neurological disorders, cardiac, and cancer. Evidence indicates that Ca2+ signaling and epigenetics are involved in the same cellular functions, which suggests a possible interplay between both mechanisms. Ca2+-activated transcription factors regulate the recruitment of chromatin remodeling complexes into their target genes, and Ca2+-sensing proteins modulate their activity and intracellular localization. Thus, Ca2+ signaling is an important regulator of epigenetic mechanisms. Moreover, Ca2+ signaling activates epigenetic mechanisms that in turn regulate genes involved in Ca2+ signaling, suggesting possible feedback between both mechanisms. The understanding of how epigenetics are regulated could lead to developing better therapeutical approaches.

Assessment of the relationship between the dopaminergic pathway and severe acute respiratory syndrome coronavirus 2 infection, with related neuropathological features, and potential therapeutic approaches in COVID-19 infection

Dopamine is a known catecholamine neurotransmitter involved in several physiological processes, including motor control, motivation, reward, cognition, and immune function. Dopamine receptors are widely distributed throughout the nervous system and in immune cells. Several viruses, including human immunodeficiency virus and Japanese encephalitis virus, can use dopaminergic receptors to replicate in the nervous system and are involved in viral neuropathogenesis. In addition, studies suggest that dopaminergic receptors may play a role in the progression and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. When SARS-CoV-2 binds to angiotensin-converting enzyme 2 receptors on the surface of neuronal cells, the spike protein of the virus can bind to dopaminergic receptors on neighbouring cells to accelerate its life cycle and exacerbate neurological symptoms. In addition, recent research has shown that dopamine is an important regulator of the immune-neuroendocrine system. Most immune cells express dopamine receptors and other dopamine-related proteins, indicating the importance of dopaminergic immune regulation. The increase in dopamine concentration during SARS-CoV2 infection may reduce immunity (innate and adaptive) that promotes viral spread, which could lead to neuronal damage. In addition, dopaminergic signalling in the nervous system may be affected by SARS-CoV-2 infection. COVID -19 can cause various neurological symptoms as it interacts with the immune system. One possible treatment strategy for COVID -19 patients could be the use of dopamine antagonists. To fully understand how to protect the neurological system and immune cells from the virus, we need to study the pathophysiology of the dopamine system in SARS-CoV-2 infection.

Diacylglycerol kinases: A look into the future of immunotherapy

Cancer still represents the second leading cause of death right after cardiovascular diseases. According to the World Health Organization (WHO), cancer provoked around 10 million deaths in 2020, with lung and colon tumors accounting for the deadliest forms of cancer. As tumor cells become resistant to traditional therapeutic approaches, immunotherapy has emerged as a novel strategy for tumor control. T lymphocytes are key players in immune responses against tumors. Immunosurveillance allows identification, targeting and later killing of cancerous cells. Nevertheless, tumors evolve through different strategies to evade the immune response and spread in a process called metastasis. The ineffectiveness of traditional strategies to control tumor growth and expansion has led to novel approaches considering modulation of T cell activation and effector functions. Program death receptor 1 (PD-1) and cytotoxic T-lymphocyte antigen 4 (CTLA-4) showed promising results in the early 90s and nowadays are still being exploited together with other drugs for several cancer types. Other negative regulators of T cell activation are diacylglycerol kinases (DGKs) a family of enzymes that catalyze the conversion of diacylglycerol (DAG) into phosphatidic acid (PA). In T cells, DGKα and DGKζ limit the PLCγ/Ras/ERK axis thus attenuating DAG mediated signaling and T cell effector functions. Upregulation of either of both isoforms results in impaired Ras activation and anergy induction, whereas germline knockdown mice showed enhanced antitumor properties and more effective immune responses against pathogens. Here we review the mechanisms used by DGKs to ameliorate T cell activation and how inhibition could be used to reinvigorate T cell functions in cancer context. A better knowledge of the molecular mechanisms involved upon T cell activation will help to improve current therapies with DAG promoting agents.

The ER stress sensor IRE1 interacts with STIM1 to promote store-operated calcium entry, T cell activation, and muscular differentiation

Store-operated Ca2+ entry (SOCE) mediated by stromal interacting molecule (STIM)-gated ORAI channels at endoplasmic reticulum (ER) and plasma membrane (PM) contact sites maintains adequate levels of Ca2+ within the ER lumen during Ca2+ signaling. Disruption of ER Ca2+ homeostasis activates the unfolded protein response (UPR) to restore proteostasis. Here, we report that the UPR transducer inositol-requiring enzyme 1 (IRE1) interacts with STIM1, promotes ER-PM contact sites, and enhances SOCE. IRE1 deficiency reduces T cell activation and human myoblast differentiation. In turn, STIM1 deficiency reduces IRE1 signaling after store depletion. Using a CaMPARI2-based Ca2+ genome-wide screen, we identify CAMKG2 and slc105a as SOCE enhancers during ER stress. Our findings unveil a direct crosstalk between SOCE and UPR via IRE1, acting as key regulator of ER Ca2+ and proteostasis in T cells and muscles. Under ER stress, this IRE1-STIM1 axis boosts SOCE to preserve immune cell functions, a pathway that could be targeted for cancer immunotherapy.

Transcription factors in the development and treatment of immune disorders

Immune function is highly controlled at the transcriptional level by the binding of transcription factors (TFs) to promoter and enhancer elements. Several TF families play major roles in immune gene expression, including NF-κB, STAT, IRF, AP-1, NRs, and NFAT, which trigger anti-pathogen responses, promote cell differentiation, and maintain immune system homeostasis. Aberrant expression, activation, or sequence of isoforms and variants of these TFs can result in autoimmune and inflammatory diseases as well as hematological and solid tumor cancers. For this reason, TFs have become attractive drug targets, even though most were previously deemed "undruggable" due to their lack of small molecule binding pockets and the presence of intrinsically disordered regions. However, several aspects of TF structure and function can be targeted for therapeutic intervention, such as ligand-binding domains, protein-protein interactions between TFs and with cofactors, TF-DNA binding, TF stability, upstream signaling pathways, and TF expression. In this review, we provide an overview of each of the important TF families, how they function in immunity, and some related diseases they are involved in. Additionally, we discuss the ways of targeting TFs with drugs along with recent research developments in these areas and their clinical applications, followed by the advantages and disadvantages of targeting TFs for the treatment of immune disorders.

TCR ligand potency differentially impacts PD-1 inhibitory effects on diverse signaling pathways

Checkpoint blockade revolutionized cancer therapy, but we still lack a quantitative, mechanistic understanding of how inhibitory receptors affect diverse signaling pathways. To address this issue, we developed and applied a fluorescent intracellular live multiplex signal transduction activity reporter (FILMSTAR) system to analyze PD-1-induced suppressive effects. These studies identified pathways triggered solely by TCR or requiring both TCR and CD28 inputs. Using presenting cells differing in PD-L1 and CD80 expression while displaying TCR ligands of distinct potency, we found that PD-1-mediated inhibition primarily targets TCR-linked signals in a manner highly sensitive to peptide ligand quality. These findings help resolve discrepancies in existing data about the site(s) of PD-1 inhibition in T cells while emphasizing the importance of neoantigen potency in controlling the effects of checkpoint therapy.

Polyadenosine diphosphate-ribose polymerase inhibitors: advances, implications, and challenges in tumor radiotherapy sensitization

Polyadenosine diphosphate-ribose polymerase (PARP) is a key modifying enzyme in cells, which participates in single-strand break repair and indirectly affects double-strand break repair. PARP inhibitors have shown great potential in oncotherapy by exploiting DNA damage repair pathways, and several small molecule PARP inhibitors have been approved by the U.S. Food and Drug Administration for treating various tumor types. PARP inhibitors not only have significant antitumor effects but also have some synergistic effects when combined with radiotherapy; therefore they have potential as radiation sensitizers. Here, we reviewed the advances and implications of PARP inhibitors in tumor radiotherapy sensitization. First, we summarized the multiple functions of PARP and the mechanisms by which its inhibitors exert antitumor effects. Next, we discuss the immunomodulatory effects of PARP and its inhibitors in tumors. Then, we described the theoretical basis of using PARP inhibitors in combination with radiotherapy and outlined their importance in oncological radiotherapy. Finally, we reviewed the current challenges in this field and elaborated on the future applications of PARP inhibitors as radiation sensitizers. A comprehensive understanding of the mechanism, optimal dosing, long-term safety, and identification of responsive biomarkers remain key challenges to integrating PARP inhibition into the radiotherapy management of cancer patients. Therefore, extensive research in these areas would facilitate the development of precision radiotherapy using PARP inhibitors to improve patient outcomes.

BATF represses BIM to sustain tolerant T cells in the periphery

T cells that encounter self-antigens after exiting the thymus avert autoimmunity through peripheral tolerance. Pathways for this include an unresponsive state known as anergy, clonal deletion, and T regulatory (Treg) cell induction. The transcription factor cues and kinetics that guide distinct peripheral tolerance outcomes remain unclear. Here, we found that anergic T cells are epigenetically primed for regulation by the non-classical AP-1 family member BATF. Tolerized BATF-deficient CD4+ T cells were resistant to anergy induction and instead underwent clonal deletion due to proapoptotic BIM (Bcl2l11) upregulation. During prolonged antigen exposure, BIM derepression resulted in fewer PD-1+ conventional T cells as well as loss of peripherally induced FOXP3+ Treg cells. Simultaneous Batf and Bcl2l11 knockdown meanwhile restored anergic T cell survival and Treg cell maintenance. The data identify the AP-1 nuclear factor BATF as a dominant driver of sustained T cell anergy and illustrate a mechanism for divergent peripheral tolerance fates.

Enhanced production of IL-2 from anti-CD3 antibody-stimulated mouse spleen cells by caffeic acid phenethyl ester, a major component of Chinese propolis

OBJECTIVES

We evaluated the immune-modulatory effects of Chinese propolis (CP) and its major constituent, caffeic acid phenethyl ester (CAPE), on the cytokine production of anti-CD3 antibody-stimulated mouse spleen cells.

METHODS

Mouse spleen cells stimulated by anti-CD3 monoclonal antibody were co-cultured with CP, CAPE, and HC030031, a specific antagonist of the TRPA1 Ca2+-permeable cation channel. Cytokine production was assayed by enzyme-linked immunosorbent assay. Interleukin (IL)-2 mRNA expression was examined by reverse transcription-quantitative polymerase chain reaction.

RESULTS

In stimulated spleen cells treated with 1/16,000 CP diluent, IL-2 production was markedly enhanced, while IL-4 and IL-10 productions were not significantly affected. In contrast, interferon (IFN)-γ, IL-6, and IL-17 productions were markedly reduced. These effects of CP were reproduced by the CAPE treatment. A time-course observation demonstrated that, compared to control cells, IL-2 mRNA expression and production were significantly enhanced in the spleen cells stimulated by CAPE; however, IL-2 production was markedly delayed compared to that in the untreated control cells. The enhancement of IL-2 production by CAPE was scarcely alleviated by the addition of HC030031. These effects of CAPE upon IL-2 mRNA production were abolished in spleen cells without anti-CD3 antibody stimulation.

CONCLUSIONS

CAPE is an important regulator of CP for cytokine regulation in anti-CD3 antibody-stimulated spleen cells. The agent specifically reduced IFN-γ, IL-6, and IL-17 and slightly enhanced Th2 cytokine production while significantly enhancing IL-2 production at the transcriptional level.

Role of APR3 in cancer: apoptosis, autophagy, oxidative stress, and cancer therapy

APR3 (Apoptosis-related protein 3) is a gene that has recently been identified to be associated with apoptosis. The gene is located on human chromosome 2p22.3 and contains both transmembrane and EGF (epidermal growth factor)-like domains. Additionally, it has structural sites, including AP1, SP1, and MEF2D, that indicate NFAT (nuclear factor of activated T cells) and NF-κB (nuclear factor kappa-B) may be transcription factors for this gene. Functionally, APR3 participates in apoptosis due to the induction of mitochondrial damage to release mitochondrial cytochrome C. Concurrently, APR3 affects the cell cycle by altering the expression of Cyclin D1, which, in turn, affects the incidence and growth of malignancies and promotes cell differentiation. Previous reports indicate that APR3 is located in lysosomal membranes, where it contributes to lysosomal activity and participates in autophagy. While further research is required to determine the precise role and molecular mechanisms of APR3, earlier studies have laid the groundwork for APR3 research. There is growing evidence supporting the significance of APR3 in oncology. Therefore, this review aims to examine the current state of knowledge on the role of the newly discovered APR3 in tumorigenesis and to generate fresh insights and suggestions for future research.

Harnessing IGF-1 and IL-2 as biomarkers for calcineurin activity to tailor optimal FK506 dosage in α-synucleinopathies

Introduction: Rise in Calcium (Ca2+) and hyperactive Ca2+-dependent phosphatase calcineurin represent two key determinants of a-synuclein (a-syn) pathobiology implicated in Parkinson's Disease (PD) and other neurodegenerative diseases. Calcineurin activity can be inhibited with FK506, a Food and Drug Administration (FDA)-approved compound. Our previous work demonstrated a protective effect of low doses of FK506 against a-syn pathology in various models of a-syn related pathobiology. Methods: Control and a-syn-expressing mice (12-18 months old) were injected with vehicle or two single doses of FK506 administered 4 days apart. Cerebral cortex and serum from these mice were collected and assayed using a meso scale discovery quickplex SQ 120 for cytokines and Enzyme-linked immunosorbent assay for IGF-1. Results: In this study we present evidence that reducing calcineurin activity with FK506 in a-syn transgenic mice increased insulin growth factor (IGF-1), while simultaneously decreasing IL-2 levels in both cerebral cortex and serum. Discussion: The highly conserved Ca2+/calcineurin signaling pathway is known to be affected in a-syn-dependent human disease. FK506, an already approved drug for other uses, exhibits high brain penetrance and a proven safety profile. IL-2 and IGF-1 are produced throughout life and can be measured using standard clinical methods. Our findings provide two potential biomarkers that could guide a clinical trial of FK506 in PD patients, without posing significant logistical or regulatory challenges.