FOXP3+ regulatory T cells in the human immune system. Nat Rev Immunol. 2010;10:490-500. [PMID: 20559327 DOI: 10.1038/nri2785]

Schistosoma japonicum cystatin attenuated CLP-induced sepsis in mice though inducing tolerogenic dendritic cells and regulatory T cells

Sepsis is a life-threatening complication caused by the overwhelming immune response to bacterial infection leading to the fatal organ damage and even death. Helminth infections modulate host's immune system through secreting functional proteins to reduce host immune attack as a survival strategy, therefore have been used for the therapy of some inflammatory or autoimmune diseases. Sj-Cys is a cysteine protease inhibitor secreted by Schistosoma japonicum exerting strong immunomodulatory function which has been used to treat sepsis, however, the mechanism underlying the therapeutic efficacy has not been fully elucidated. In this study, we expressed Sj-Cys as recombinant protein (rSj-Cys) in prokaryotic system and rSj-Cys was used to incubate with mouse bone marrow derived dendritic cells (BMDCs) in vitro. Our study revealed that rSj-Cys was able to induce differentiation of BMDCs to tolerant property (TolDCs). Adoptive transfer of rSj-Cys induced-TolDCs into mice with cecal ligation and puncture (CLP)-induced sepsis conferred a significant therapeutic effect on CLP-induced sepsis in mice with reduced mortality and vital organ damage. The therapeutic effect of Sj-Cys-induced TolDCs was associated with upregulation of CD3+CD4+CD25+Foxp3+ regulatory T cells (Tregs) and reduced inflammatory cytokines IL-6 and TNF-α and boosted level of regulatory cytokines IL-10 and TGF-β. The results identified in this study further suggest rSj-Cys has the potential to be developed into a drug substance for the treatment of inflammatory or autoimmune diseases due to its immunomodulatory effect on tolerant dendritic cells and regulatory T cells.

Targeting Setdb1 in T cells induces transplant tolerance without compromising antitumor immunity

Suppressing immune responses promotes allograft survival but also favours tumour progression and recurrence. Selectively suppressing allograft rejection while maintaining or even enhancing antitumor immunity is challenging. Here, we show loss of allograft-related rejection in mice deficient in Setdb1, an H3K9 methyltransferase, while antitumor immunity remains intact. RNA sequencing shows that Setdb1-deficiency does not affect T-cell activation or cytokine production but induces an increase in Treg-cell-associated gene expression. Depletion of Treg cells impairs graft acceptance in Setdb1-deficient mice, indicating that the Treg cells promote allograft survival. Surprisingly, Treg cell-specific Setdb1 deficiency does not prolong allograft survival, suggesting that Setdb1 may function prior to Foxp3 induction. Using single-cell RNA sequencing, we find that Setdb1 deficiency induces a new Treg population in the thymus. This subset of Treg cells expresses less IL-1R2 and IL-18R1. Mechanistically, during Treg cell induction, Setdb1 is recruited by transcription factor ATF and altered histone methylation. Our data thus define Setdb1 in T cells as a hub for Treg cell differentiation, in the absence of which suppressing allograft rejection is uncoupled from maintaining antitumor immunity.

Allergic disease and risk of multiple myeloma: A case-control study

BACKGROUND AND AIMS

Multiple myeloma (MM) is responsible for significant morbidity and mortality, yet our knowledge regarding MM aetiology remains limited. We investigated whether a history of allergic conditions is associated with MM risk.

METHODS

Incident cases (n = 782) of MM were recruited via cancer registries in Victoria and NSW. Controls (n = 733) were siblings (n = 436) or spouses (n = 297) of cases. Unconditional logistic regression was used to estimate odds ratios (OR) and 95 % confidence intervals (CI) for associations between self-reported allergic conditions (asthma, eczema, food allergy, hay fever) and MM risk.

RESULTS

Eczema was inversely associated with MM risk (OR = 0.54, 95 %CI = 0.42-0.70), as was a combined history of food allergy and eczema (OR = 0.52, 95 %CI = 0.29-0.93). There was an inverse association between a history of any allergic condition (compared with none) and risk of MM (OR = 0.68, 95 %CI = 0.55-0.84). In the mean-centred dose-risk analysis the OR was 0.87 (95 %CI = 0.73-1.04) per additional allergic condition of interest. No notable associations were identified for food allergy, asthma, or hay fever alone.

CONCLUSIONS AND FUTURE DIRECTIONS

We found that a history of allergic disease, particularly eczema, was associated with reduced MM risk. Further research is recommended to confirm findings and investigate potential mechanisms.

The role of cell exhaustion in lepromatous leprosy

Leprosy is a neglected chronic infectious disease caused by Mycobacterium leprae or M. lepromatosis, representing a public health concern in several low-income countries. In Brazil, most patients develop lepromatous leprosy, a clinical form characterized by poor bacillary control due to T helper 2 cells, M2 macrophages, and accentuated humoral immunity. Despite extensive studies, the complete mechanism of the disease is not fully understood. The evasion mechanisms used by the pathogen likely involve cellular exhaustion, which can arise from chronic antigen stimulation, leading to dysfunction at immune checkpoints, a progressive loss of T lymphocyte effector function, and low production of proinflammatory cytokines. Our study investigated the contribution of cellular exhaustion to the hyporesponsiveness of lepromatous leprosy patients by evaluating the classical markers PD-1 and LAG-3, their ligands PD-L1 and PD-L2, and the functional activity of cells after PD-1 blockade, using flow cytometry, immunofluorescence, and gene expression analyses in both blood and skin. Our work shows for the first time that LAG-3 is increased in the skin lymphocytes of lepromatous patients, as well as membrane-bound and soluble PD-1. Furthermore, its classical ligands, PD-L1 and PD-L2, are more available for interaction in all monocyte subsets in these patients. We also identified that PD-1 blockade induces an increase in IFN-γ+ and TNF+ T lymphocytes. Taken together, our data suggest that exhaustion markers contribute to the hyporesponsive profile of lepromatous patients, and that PD-1 blockade could contribute to the reestablishment of lymphocyte effector action and potentially become part of multidrug therapy in the future.

Reversing the immunosuppressive tumor microenvironment via "Kynurenine starvation therapy" for postsurgical triple-negative breast cancer treatment

Immunotherapy is a potential strategy to suppress the postoperative recurrence and metastasis of triple-negative breast cancer (TNBC). However, the excessive accumulation of kynurenine (Kyn) leads to immunosuppressive tumor microenvironment (TME) and impedes immunotherapeutic efficacy. Herein, a two-pronged approach through "Kynurenine Starvation Therapy" is proposed based on the in-situ hydrogel implantation for postsurgical treatment of TNBC. The hydrogel is constructed via Schiff base reaction between oxidized dextran (ODEX) and 8-arm poly(ethylene glycol) amine (8-arm PEG-NH2), which exhibits excellent biocompatibility and gradual biodegradability. The indoleamine 2,3-dioxygenase 1 (IDO1) inhibitor NLG919 and kynureninase (KYNase) are noncovalently loaded into the hydrogel to prepare NLG919 + KYNase@Gel. The obtained hydrogel can sustainably release NLG919 and KYNase to synergistically deplete Kyn, thereby reversing immunosuppression to enhance the antitumor immunity within TME through "Kynurenine Starvation Therapy". Moreover, a single implantation of NLG919 + KYNase@Gel not only effectively inhibits the postoperative recurrence and metastasis in 4 T1 tumor-bearing mice, but also restrains the growth in an orthotopic TNBC mouse model. These findings highlight an innovative strategy to reinforce the antitumor immune response for the treatment of postsurgical TNBC.

Diagnostic Accuracy of Serum P16ink4A and FOX-P3 Concentrations for Detection of Cervical Lesions Among Women Attending a Cervical Cancer Clinic in Western Uganda: A Case-Control Study

Introduction: Expression of P16ink4A and FOXP3 is correlated with the grades of cervical lesions. In this study, we determined the diagnostic accuracy of serum P16ink4A and FOXP3 concentrations for detection of cervical intraepithelial neoplasia (CIN) and cervical cancer (CC) in a rural setting in Southwestern Uganda. Material and Methods: CIN and CC cases (93 each before treatment), and 93 controls were identified. Clinical and demographic data were documented before quantifying serum P16ink4A and FOXP3 concentrations using quantitative ELISA kits. Cases were confirmed by cytology and/or histology. We employed descriptive statistics, cross-tabulation, and receiver operating curves (ROC) using statistical software for data science (STATA) 17. p-values <0.05 were considered statistically significant. Results: Serum FOXP3 concentration of 0.0545 ng/mL < showed moderate sensitivity (32.22% and 57.78%) for detection of CIN and CC from healthy controls, respectively. It also showed a moderately high specificity of 68.89% for detection of both CIN and CC from healthy controls (AUC-0.6014 and 0.7679, respectively). Serum P16ink4A concentration of 0.946 ng/mL < showed moderate sensitivities (50.00% and 60.00%) and specificities (56.67% and 55.56%) for the detection of CIN and CC from healthy controls, respectively (AUC-0.6085 and 0.7592, respectively). A combination of elevated serum FOXP3 and P16ink4A showed very low sensitivities of 18.89% in detecting CIN from healthy controls and 33.33% for detecting CC from healthy controls. This combination showed high specificity of 83.33% in detecting both CIN and CC from healthy controls (AUC-0.5992 and 0.7642, respectively). Conclusion: Although serum P16ink4A and FOXP3 concentrations showed moderate accuracy, their combination was more specific than sensitive. This combination has a high potential to be applied for diagnosis rather than screening for cervical lesions, at least in the Ugandan population. Combinations of P16ink4A and FOXP3 with other biomarkers could improve diagnostic accuracies. Additionally, studies could be conducted to assess the performance of these biomarkers in the detection of cervical lesions in specific populations, say Human Immunodeficiency Virus (HIV)-positive and HIV-negative populations.

Feedback regulation of VISTA and Treg by TNF-α controls T cell responses in drug allergy

BACKGROUND

Severe cutaneous adverse reactions (SCARs) mediated by cytotoxic T lymphocytes are a series of life-threatening conditions with a mortality of 4%-20%. The clinical application of tumor necrosis factor-alpha (TNF-α) antagonist improves the outcome of some SCARs patients; however, this is complicated by the elusive and varied immunopathogenesis.

METHODS

To clarify the precise process and optimize the therapy regimen of SCARs, we performed single-cell sequencing, in vitro functional and clinical analysis of patients with SCARs.

RESULTS

We observed that TNF-α breaks drug-specific T-cell tolerance by inhibiting the expression of V-type immunoglobulin domain-containing suppressor of T-cell activation (VISTA). Furthermore, TNF-α generated a positive feedback loop in the early phase of drug-specific T-cell activation, whereby B cells acted reciprocally on the corresponding T cells to reinforce TNF-α cytokine expression. In contrast, this pathway of TNF-α-VISTA signaling did not operate in memory effector T cells. Drug-specific memory effector T-cell responses were inhibited by increasing Treg cell expression in a negative feedback loop, with TNF-α antagonists preventing the inhibitory effect. These observations align with the clinical analysis that early but not late intervention with TNF-α antagonists significantly improved outcomes in SCARs patients.

CONCLUSION

Our findings defining feedback regulation of VISTA and Treg cells by TNF-α in different stages of the drug-specific T-cell response and, indicate that a Treg agonists, instead of TNF-α antagonists, could be used for treatment of patients with progressive SCARs.

Tumor microenvironment as niche constructed by cancer stem cells: Breaking the ecosystem to combat cancer

BACKGROUND

Cancer stem cells (CSCs) are a distinct subpopulation of cancer cells with the capacity to constantly self-renew and differentiate, and they are the main driver in the progression of cancer resistance and relapse. The tumor microenvironment (TME) constructed by CSCs is the "soil" adapted to tumor growth, helping CSCs evade immune killing, enhance their chemical resistance, and promote cancer progression.

AIM OF REVIEW

We aim to elaborate the tight connection between CSCs and immunosuppressive components of the TME. We attempt to summarize and provide a therapeutic strategy to eradicate CSCs based on the destruction of the tumor ecological niche.

KEY SCIENTIFIC CONCEPTS OF REVIEW

This review is focused on three main key concepts. First, we highlight that CSCs recruit and transform normal cells to construct the TME, which further provides ecological niche support for CSCs. Second, we describe the main characteristics of the immunosuppressive components of the TME, targeting strategies and summarize the progress of corresponding drugs in clinical trials. Third, we explore the multilevel insights of the TME to serve as an ecological niche for CSCs.

Interleukin 17-producing C-C motif chemokine receptor 6 + conventional CD4+ T cells are arthritogenic in an animal model of spondyloarthritis

OBJECTIVE

Spondyloarthritis (SpA) is a group of chronic inflammatory disorders associated with the human leukocyte antigen (HLA) class I allele HLA-B27. Transgenic rats expressing HLA-B27 and human β2-microglobulin (B27 rats) develop clinical manifestations resembling SpA called rat SpA. IL-17 and TNF are key proinflammatory cytokines implicated in both human and rat SpA. We aimed to determine which T cell subset(s) produce IL-17 and TNF during rat SpA, characterize their tissue distribution and tested their pathogenicity in vivo.

METHODS

Cytokine production by T cell subsets was evaluated in target tissues and lymphoid organs during rat SpA. Pathogenicity of purified IL-17+ cells was assessed in vivo by cell transfer. Blood samples were used to translate B27 rats findings to SpA patients.

RESULTS

Conventional CD4+ T cells (Foxp3-; Tconv) and γδ T cells were the main producers of both IL-17 and TNF in B27 rats. IL-17-producing Tconv and γδ T cells were expanded in the colon of premorbid 3-weeks-old B27 rats. C-C motif chemokine receptor 6 (CCR6) allowed the isolation of IL-17+ Tconv (Th17) in rat. Transfer of B27 rat IL-17-producing CCR6+ Tconv but not of γδ T cells into disease-free nude B27 rats induced arthritis, directly demonstrating for the first time the arthritogenic potential of Th17 cells in SpA. Finally, a CCR6+ IL-17+ Tconv expansion enriched for IL-17F production was evidenced in SpA patients.

CONCLUSION

Our study demonstrates that IL-17+TNF+CCR6+ Th17 cells and IL-17+ γδ T cells are expanded preceding SpA onset in B27 rats and that only IL-17+TNF+CCR6+ Th17 cells can trigger arthritis.

Flow Cytometry-based Immune Phenotyping of T and B Lymphocytes in the Evaluation of Immunodeficiency and Immune Dysregulation

There are approximately 500 congenital disorders that impair immune cell development and/or function. Patients with these disorders may present with a wide range of symptoms, including increased susceptibility to infection, autoimmunity, autoinflammation, lymphoproliferation, and/or atopy. Flow cytometry-based immune phenotyping of T and B lymphocytes plays an essential role in the evaluation of patients with these presentations. In this review, we describe the clinical utility of flow cytometry as part of a comprehensive evaluation of immune function and how this testing may be used as a diagnostic tool to identify underlying aberrant immune pathways, monitor disease activity, and assess infection risk.

Elucidating the Causal Link Between Treg-Related Immune Traits and Atherosclerosis-Related Cardiovascular Diseases: A Bidirectional Mendelian Randomisation Analysis

AIM

Regulatory T cells (Tregs) play a crucial role in the development and progression of atherosclerosis. However, the specific association between Treg immune traits and atherosclerosis and related cardiovascular diseases remains unclear, impeding their potential for clinical therapeutic application.

METHOD

Fifty-eight Treg-related immune traits were obtained from the latest summary level genome-wide association study, which included 3,757 individuals from Sardinia. Additionally, three atherosclerosis subsets and three atherosclerosis-related cardiovascular diseases were obtained from the FinnGen database. Subsequently, comprehensive bidirectional Mendelian randomisation (MR) analysis was performed using inverse-variance weighting as the primary method. Sensitivity analyses were performed to verify the robustness, heterogeneity, and horizontal pleiotropy of the results. Co-localisation analysis was performed to detect whether the exposure and outcome shared causal variants.

RESULTS

Four significant Treg-related immune traits linked to a lower risk of three cardiovascular diseases were identified in the forward MR analysis. Specifically, two traits were identified for cerebral atherosclerosis: CD39+ activated CD4+ Treg absolute count (OR 0.70, 95% CI 0.57-0.87, pFDR=0.040 [false discovery rate]) and activated CD4 Tregs % CD4+ T cells (OR 0.64, 95% CI 0.48-0.84, pFDR=0.040). In addition, CD28 on secreting CD4 Tregs (OR 0.95, 95% CI 0.93-0.98, pFDR=0.014) was detected for other atherosclerosis. In ischaemic heart disease, CD28 on activated CD4 Tregs was protective (OR 0.96, 95% CI 0.95-0.98, pFDR=0.020). An increased intensity of CD3 and CD4 was observed in reverse MR after the occurrence of stroke and ischaemic heart disease, respectively, whereas a lower number and proportion of CD39+-secreting CD4 Tregs were noted after ischaemic heart disease. Co-localisation analysis indicated that there were no shared causal variants among significant associations in forward MR.

CONCLUSION

This study revealed a potential causal relationship between Tregs and atherosclerosis and related cardiovascular diseases, providing a plausible hypothesis for future clinical and basic research.

The abundance of regulatory T cell subsets is associated with the clinical outcomes of sarcoidosis

OBJECTIVES

Some patients with sarcoidosis achieve spontaneous remission, whereas others repeatedly experience relapse. We examined differences in the clinical course of active sarcoidosis according to peripheral blood immunophenotypes before treatment.

METHODS

This retrospective study compared peripheral blood immunophenotypes between patients with active sarcoidosis (n = 28) and healthy control subjects (n = 10). Patients with sarcoidosis were divided into the spontaneous remission group without treatment (n = 9), the non-relapsed group after treatment (n = 13), and the relapsed group after treatment (n = 6) and were compared for peripheral blood immunophenotypes and background characteristics at baseline.

RESULTS

Patients with sarcoidosis showed increases in activated T helper (Th) 1 cells, activated Th17 cells, and regulatory T (Treg) cell subsets. The proportion of effector Treg cells was highest in the spontaneous remission group, and the proportion of non-suppressive Treg cells was highest in the relapsed group. No differences were observed in the proportions of other CD4+ T cell subsets. The cut-off values for predicting spontaneous remission and relapse were calculated for the effector Treg/non-suppressive Treg ratio. As a result, A ratio ≥1.469 predicted spontaneous remission (75%), while ≤0.722 predicted relapse (66.7%).

CONCLUSION

Effector and non-suppressive Treg cell proportions before treatment may predict spontaneous remission and relapse in active sarcoidosis.

Sialyl Lewis X (sLex):Biological functions, synthetic methods and therapeutic implications

Carbohydrates are shown to be crucial to several biological processes. They are essential mediators of cell-cell recognition processes. Among them, Sialyl Lewis X (sLex) is a very significant structure in the human body. It is a critical tetrasaccharide that plays a pivotal role in various biological processes, including cell adhesion, immune response, and cancer metastasis. Known as the blood group antigen, sLex is also referred to as cluster of differentiation 15s (CD15s) or stage-specific embryonic antigen 1 (SSEA-1). sLex is not only a prominent blood group antigen, but also involved in the attraction of sperm to the egg during fertilization, prominently displayed at the terminus of glycolipids on the cell surface. By describing the synthetic methods and biological functions of sLex, this review underscores the importance of sLex in both fundamental and applied sciences and its potential to impact clinical practice.

Effectiveness of quality and quantity mononuclear cells for enhancing wound healing in diabetic ischemic limb animal model

This study set forth to investigate the efficacy of Quality and Quantity mononuclear cells (QQMNCs) for promoting wound healing and limb salvage in a severe ischemic wound model using diabetic mice. Female BALB/c nude mice induced with diabetes were used to create ischemic limb models in a controlled experimental design. Intramuscular injections of human QQMNCs were compared to phosphate-buffered saline (PBS) and peripheral blood mononuclear cells (PBMNCs) relative to their effects on wound healing and limb salvage. In vitro analysis demonstrated that the QQMNC group had significantly higher median percentages of CD34+ cells, CD34+CD133+ cells, CD206+ cells, and FOXP3+ cells compared to the PBMNC group (all p < 0.05), which suggests an enhanced regenerative and immunomodulatory profile. Kaplan-Meier survival analysis showed a significantly higher number of completely healed wounds in the QQMNC group than in the PBMNC group (p = 0.044). The histological evaluation showed that the QQMNC group had a significantly thinner epithelial thickness than the PBMNC (p = 0.032) and PBS groups (p = 0.002), and a significantly greater T cell density than the PBS group (p = 0.033), which suggests more efficient tissue repair. Moreover, the QQMNC group exhibited the highest percentage of minor tissue loss (57% for forefoot and toe gangrene), and the lowest incidence of severe limb loss (0% for lower leg gangrene). The findings of this study highlight the effectiveness of QQMNCs for promoting wound healing and limb salvage in diabetic ischemic animal model; however, clinical trials are needed to further assess their efficacy in this clinical context.

Extracorporeal Photopheresis Enhances the Frequency and Function of Highly Suppressive FoxP3 + Treg Subsets in Heart Transplanted Individuals

BACKGROUND

Extracorporeal photopheresis (ECP) has emerged as a prophylactic and therapeutic immunomodulatory option for managing acute rejection in heart transplants (HTx). The underlying mechanisms through which ECP exerts its immunomodulatory effects remain under investigation. Regulatory T cells (Treg) are a heterogeneous subset of immune lymphocytes that ensure the maintenance of tissue homeostasis, avoiding graft rejection. The transcription factor forkhead box protein 3 (FoxP3) is an essential molecular marker of Treg, acting as a "master regulator" of their genesis, stability, and functions. No study has investigated whether ECP impacts FoxP3 expression and its highly suppressive variants containing the exon 2 (FoxP3-E2), particularly in HTx.

METHODS

In the current study, we recruited 14 HTx participants who had undergone ECP therapy. We explored the effect of in vivo ECP on CD4 + FoxP3 + Treg frequency and in vitro suppressive function in 8 HTx participants before (T0) and after 3 (T1), 6 (T2), and 12 (T3) mo of treatment. As a control group, we included 4 HTx individuals who had not undergone ECP therapy.

RESULTS

We found that ECP increases the frequency of CD4 + FoxP3 + Treg subset with highly suppressive phenotype, including CD4 + FoxP3-E2 + Treg. At functional levels, we observed that ECP treatment in HTx individuals effectively improves Treg suppressive ability in controlling the proliferation of autologous conventional CD4 + T lymphocytes.

CONCLUSIONS

Our findings collectively suggest that ECP exerts its immunomodulatory effects in HTx individuals by positively impacting the frequency and regulatory function of the FoxP3 + Treg compartment.

Key immune cells and their crosstalk in the tumor microenvironment of bladder cancer: insights for innovative therapies

Bladder cancer (BC) is a heterogeneous disease associated with high mortality if not diagnosed early. BC is classified into non-muscle-invasive BC (NMIBC) and muscle-invasive BC (MIBC), with MIBC linked to poor systemic therapy response and high recurrence rates. Current treatments include transurethral resection with Bacillus Calmette-Guérin (BCG) therapy for NMIBC and radical cystectomy with chemotherapy and/or immunotherapy for MIBC. The tumor microenvironment (TME) plays a critical role in cancer progression, metastasis, and therapeutic efficacy. A comprehensive understanding of the TME's complex interactions holds substantial translational significance for developing innovative treatments. The TME can contribute to therapeutic resistance, particularly in immune checkpoint inhibitor (ICI) therapies, where resistance arises from tumor-intrinsic changes or extrinsic TME factors. Recent advancements in immunotherapy highlight the importance of translational research to address these challenges. Strategies to overcome resistance focus on remodeling the TME to transform immunologically "cold" tumors, which lack immune cell infiltration, into "hot" tumors that respond better to immunotherapy. These strategies involve disrupting cancer-microenvironment interactions, inhibiting angiogenesis, and modulating immune components to enhance anti-tumor responses. Key mechanisms include cytokine involvement [e.g., interleukin-6 (IL-6)], phenotypic alterations in macrophages and natural killer (NK) cells, and the plasticity of cancer-associated fibroblasts (CAFs). Identifying potential therapeutic targets within the TME can improve outcomes for MIBC patients. This review emphasizes the TME's complexity and its impact on guiding novel therapeutic approaches, offering hope for better survival in MIBC.

The immunological processes behind aquaporin 4-antibody seropositive neuromyelitis optica spectrum disorders

Ever since the discovery of pathogenic aquaporin 4-specific antibodies in the serum of patients with neuromyelitis optica spectrum disorders current knowledge about clinical observations and diagnosis, and about the underlying pathology and resulting therapies have been put forward in excellent reviews and primary publications. However, in order to further develop novel strategies for the treatment of this disease, there is an urgent need to understand the immunological processes associated with the formation of the pathogenic antibodies, and with aberrant immune responses observed in affected patients. In this review, we will highlight and evaluate important studies on these processes.

Identification of a group of 9-amino-acridines that selectively downregulate regulatory T cell functions through FoxP3

FoxP3+ regulatory T cells (Tregs) are responsible for immune homeostasis by suppressing excessive anti-self-immunity. Tregs facilitate tumor growth by inhibiting anti-tumor immunity. Here, we explored the targeting of FoxP3 as a basis for new immunotherapies. In a high-throughput phenotypic screening of a drug repurposing library using human primary T cells, we identified quinacrine as a FoxP3 downregulator. In silico searches based on the structure of quinacrine, testing of sub-libraries of analogs in vitro, and validation identified a subset of 9-amino-acridines that selectively abrogated Treg suppressive functions. Mechanistically, these acridines interfered with the DNA-binding activity of FoxP3 and inhibited FoxP3-regulated downstream gene regulation. Release from Treg suppression by 9-amino-acridines increased anti-tumor immune responses both in cancer patient samples and in mice in a syngeneic tumor model. Our study highlights the feasibility of screening for small molecular inhibitors of FoxP3 as an approach to pursuing Treg-based immunotherapy.

Single-cell sequencing reveals tumor microenvironment features associated with the response to neoadjuvant immunochemotherapy in oral squamous cell carcinoma

OBJECTIVES

In recent years, immune checkpoint inhibitors have shown promise as neoadjuvant therapies in the treatment of locally advanced oral squamous cell carcinoma (OSCC). However, the factors affecting the tumor response to immune checkpoint inhibitors (ICIs) remain unclear. This study aimed to analyze the impact of neoadjuvant chemoimmunotherapy (NACI) on the tumor microenvironment of OSCC via single-cell RNA sequencing, with the goal of optimizing treatment strategies.

METHODS

We analyzed biopsy, primary tumor, matched metastatic lymph node, and normal lymph node samples from four patients with OSCC receiving two cycles of tislelizumab (200 mg), albumin-bound paclitaxel (260 mg/m2), and cisplatin (60-75 mg/m2), with 3-week intervals between each cycle. This study explored the tumor microenvironment characteristics of tumors and metastatic lymph nodes in response to NACI.

RESULTS

We identified two major tumor cell subpopulations (C9 and C11), and patients with high expression of C11 subgroup-specific genes had a lower survival rate. FOXP3+ CD4 eTreg cells were found to potentially suppress the immune response. We found that NACI enhances antitumor immunity by promoting the proliferation of granzyme-expressing CD8+ T effector cells while simultaneously diminishing the effect of CD4+ T cells on Treg-mediated immune suppression. Furthermore, NACI was effective in suppressing inflammatory processes mediated by myeloid cells in tumors, contributing to its antitumor effects. The CCL19+ fibroblastic reticular cell (FRC) subgroup was significantly associated with the efficacy of NACI in patients with OSCC. We found that CCL19+ FRCs primarily exert their antitumor effects through interactions with CD8+ T lymphocytes via the -CXCL12‒CXCR4 axis.

CONCLUSION

We explored the immune landscape of primary OSCC tumors and metastatic lymph nodes in relation to clinical response to NACI. Our findings offer valuable insights into patient treatment responses and highlight potential new therapeutic targets for the future management of OSCC.

Lactobacillus rhamnosus GG ameliorates atherosclerosis via suppression of oxidative stress and inflammation by reshaping the gut microbiota

OBJECTIVE

With growing awareness of probiotics' benefits, more studies are exploring their efficacy and mechanisms in reducing atherosclerosis (AS). This study aimed to investigate the potential therapeutic effects of Lactobacillus rhamnosus GG (LGG) on atherosclerotic mice and underlying mechanisms.

DESIGN

ApoE-/- mice were gavaged with a dose of 2 × 109 CFU LGG per mouse once daily, while both ApoE-/- and C57BL/6J mice received normal saline as controls. After 15 weeks, en face Oil Red O staining and aortic sinus morphometry were used to assess the effects of LGG intervention on AS. The expression of the Nrf2/HO-1 pathway, along with oxidative stress and inflammation, was measured in the aortic sinus, aortas, or plasma. Immune cells were analyzed by flow cytometry. 16S rRNA gene sequencing analysis evaluated structural changes in the intestinal microbiota.

RESULTS

LGG-treated ApoE-/- mice showed a significant reduction of AS progression by suppressing oxidative stress and inflammation. Mechanistically, LGG intervention significantly increased the levels of Nrf2/HO-1 in the aortic sinus of ApoE-/- mice. Moreover, decreased aortic macrophages and elevated blood regulatory T cells (Tregs) were found with LGG intervention in the murine AS model. Moreover, compared to C57BL/6J mice, ApoE-/- mice exhibited disrupted intestinal flora. Nonetheless, LGG intervention restored their intestinal flora to a composition resembling that of C57BL/6J mice, thereby increasing the abundance of beneficial bacteria.

CONCLUSION

LGG significantly attenuates AS by reducing oxidative stress and inflammation probably via activating the Nrf2/HO-1 pathway. Remarkably, LGG modulates gut microbiota, further enhancing its protective efficacy against AS.

The multifaceted role of SMAD4 in immune cell function

The Transforming Growth Factor-beta (TGF-β) signaling pathway, with SMAD4 as its central mediator, plays a pivotal role in regulating cellular functions, including growth, differentiation, apoptosis, and immune responses. While extensive research has elucidated SMAD4's role in tumorigenesis, its functions within immune cells remain underexplored. This review synthesizes current knowledge on SMAD4's diverse roles in various immune cells such as T cells, B cells, dendritic cells, and macrophages, highlighting its impact on immune homeostasis and pathogen response. Understanding SMAD4's role in immune cells is crucial, as its dysregulation can lead to autoimmune disorders, chronic inflammation, and immune deficiencies. The review emphasizes the significance of SMAD4 in immune regulation, proposing that deeper investigation could reveal novel therapeutic targets for immune-mediated conditions. Insights into SMAD4's involvement in processes like T cell differentiation, B cell class switch recombination, and macrophage polarization underscore its potential as a therapeutic target for a range of diseases, including autoimmune disorders and cancer.

Breast cancer stem cells convert anti-tumor CD4+ T cells to pro-tumor T regulatory cells: Potential role of exosomal FOXP3

Cancer progression and its treatment-response are regulated by the tumor microenvironment (TME). Tumor-initiating cancer stem cells (CSCs) remain in constant communication with the TME, and modulate it through several mechanisms. Here, from in-silico findings and analyzing breast cancer patient tissue-derived data, CSCs and Tregs were found to be positively correlated. Furthermore, our in-silico analyses highlighted a positive relationship between CSC genes and Treg signature marker, FOXP3, even in cancer cell lines that do not contain any T cell or Treg cells, thus raising the possibility of CSCs expressing FOXP3. Validating our hypothesis, higher expression of FOXP3, both at mRNA and protein levels, was observed in breast CSCs than non-stem cancer cells. Since a small population of CSCs initiate tumor in immune cell-dominated TME, we aimed at exploring whether breast CSCs directly transfer FOXP3 to CD4+T cells to generate immunosuppressive Treg cells. First, our search revealed CSC-derived exosomes (CDEs) generated CD4+CD25+FOXP3+ Tregs at an early time-point of 24 h, which were immunosuppressive in nature. Next, detecting presence of FOXP3 protein in CDEs showed a strong possibility of FOXP3 transfer through CDEs. This was supported by detecting elevated FOXP3 levels from 12 h in translation inhibitor-treated T cells upon CDE-exposure. Finally, exosomes derived from FOXP3 attenuated-CSCs furnished lower FOXP3 in T cells than control CDEs. This mechanism was validated in in-vivo murine model. Together these results indicate a hitherto unexplored role of CSC-derived FOXP3 in reprogramming T cells into immunosuppressive Treg cells.

Platelets Modulate Leukocyte Population Composition Within Perivascular Adipose Tissue

Perivascular adipose tissue (PVAT) regulates vascular tone and is composed of adipocytes and several leukocyte subpopulations. Diet can modify PVAT function, as obesogenic diets cause morphological changes to adipocytes and skew the leukocyte phenotype, leading to PVAT dysregulation and impaired vasoregulation. Of note, platelets, the clot-forming cells, also modulate many facets of leukocyte activity, such as tissue infiltration and polarity. We aimed to determine whether platelets regulate the leukocyte populations residing within PVAT. Male C57Bl/6J mice were fed a Western diet (30% kcal sucrose, 40% kcal fat, 8.0% sodium) to develop obesogenic conditions for PVAT leukocyte remodeling. Diet was either administered acutely (2 weeks) or extended (8 weeks) to gauge the length of challenge necessary for remodeling. Additionally, platelet depletion allowed for the assessment of platelet relevance in PVAT leukocyte remodeling. Abdominal PVAT (aPVAT) and thoracic PVAT (tPVAT) were then isolated and leukocyte composition evaluated by flow cytometry. Compared to control, Western diet alone did not significantly impact PVAT leukocyte composition for either diet length. Platelet depletion, independent of diet, significantly disrupted PVAT leukocyte content with monocytes/macrophages most impacted. Furthermore, tPVAT appeared more sensitive to platelet depletion than aPVAT, providing novel evidence of platelet regulation of leukocyte composition within PVAT depots.

Unleashing the Power of immune Checkpoints: A new strategy for enhancing Treg cells depletion to boost antitumor immunity

Regulatory T (Treg) cells, immunosuppressive CD4+ T cells, can impede anti-tumor immunity, complicating cancer treatment. Since their discovery, numerous studies have been dedicated to understand Treg cell biology, with a focus on checkpoint pathways' role in their generation and function. Immune checkpoints, such as PD-1/PD-L1, CTLA-4, TIGIT, TIM-3, and OX40, are pivotal in controlling Treg cell expansion and activity in the tumor microenvironment (TME), affecting their ability to suppress immune responses. This review examines the complex relationship between these checkpoints and Tregs in the TME, and how they influence tumor immunity. We also discuss the therapeutic potential of targeting these checkpoints to enhance anti-tumor immunity, including the use of immune checkpoint blockade (ICB) therapies and novel approaches such as CCR8-targeted therapies. Understanding the interaction between immune checkpoints and Treg cells can lead to more effective immunotherapeutic strategies, such as combining CCR8-targeted therapies with immune checkpoint inhibitors, to improve patient outcomes in cancer treatment.

A comprehensive review of the roles of T-cell immunity in preeclampsia

Preeclampsia (PE) is an obstetrical disorder that occurs after the 20th week of gestation. It is recognized as one of the "Great Obstetrical Syndromes" and principally contributes to maternal morbidity and mortality. PE has been associated with a range of immune disorders, including a preponderance of T helper (Th) 1 over Th2 cells and imbalanced levels of Th17 and T regulatory cells (Tregs). During pregnancy, T cells safeguard the placenta against immune rejection and aid embryo implantation while involved in pregnancy complications, such as PE. Promoting alloantigen-specific Treg cells is a potential preventive and therapeutic strategy for PE. However, ensuring the safety of mothers and infants is of the utmost importance since the risk-benefit ratio of reproductive and obstetric conditions differs significantly from that of immune diseases that pose a life-threatening risk. In this review, we systematically summarize the roles of T-cell immunity in the peripheral blood, reproductive tissues, and at the maternal-fetal interface of PE patients. Furthermore, the recent therapeutic approaches centered on targeting T cell immunity in PE are critically appraised.

Immunomodulation of T cell-mediated alloimmunity by proximity to endothelial cells under the mammalian target of rapamycin blockade

Endothelial cells (ECs) are an initial barrier between vascularized organ allografts and the host immune system and are thus well positioned to initiate and influence alloimmune rejection. The mammalian target of rapamycin inhibitor rapamycin is known to inhibit T cell activation and attenuate acute allograft rejection. It also has numerous effects on ECs. We hypothesized that A mammalian target of rapamycin blockade might directly alter EC alloimmunogenicity and reduce alloimmune responses independent of its effects on T cell function. Here we report that rapamycin treatment modulates EC coinhibitory ligand expression and alters cytokine/chemokine production. It alters the EC transcriptome broadly associated with negative regulation of immune responses. Rapamycin-treated ECs suppress EC-specific T cell proliferation independent of programmed cell death 1/programmed death-ligand interaction and inhibit T cells responding to adjacent allogeneic cells in a contact-independent manner via secreted inhibitory mediators above 10 kDa. The T cell hyporesponsiveness induced by rapamycin-pretreated ECs was rescued by exogenous interleukin 2. Preexposing donor hearts to rapamycin improves the effect of B7 costimulation blockade in prolonging heart allograft survival in a major histocompatibility complex-mismatched mouse model. Our results indicate that rapamycin-treated ECs have reduced alloimmunogenicity and created a local, contact-independent environment that limits T cell alloreactivity via anergy induction and improves the efficacy of B7 costimulation blockade.

The possible anti-tumor effects of regulatory T cells plasticity / IL-35 in the tumor microenvironment of the major three cancer types

T lymphocytes are among the immunological cells that make up the tumor microenvironment (TME), and they are essential in the growth of tumors and anti-tumor reactions. Regulatory T cells (Treg cells) are a subset of CD4+ T cells in the immune system that suppress the immune system. They are distinguished by their expression of the master transcription factor forkhead box protein P3 (FOXP3). Furthermore, Treg cells are essential for maintaining immunological homeostasis, inhibiting inflammation, and maintaining self-tolerance. In a variety of malignancies within the TME, Treg cells demonstrate notable flexibility and functional diversity. Highly plastic Treg cells can change into Th-like Treg cells in specific circumstances, which allow them to secrete particular pro-inflammatory cytokines. Interleukin 35 (IL-35) is a part of the immunosuppressive cytokines that belong to the IL-12 family. Treg cells release IL-35, which was elevated in the peripheral blood and TME of numerous cancer patients, implying that IL-35 in the TME may be an intriguing target for cancer therapy. In cancer, IL-35 is a two-edged sword; it promotes tumorigenicity in cancer cells while shielding them from apoptosis. Nonetheless, other investigations have mentioned its conflicting effects on cancer prevention. Herein, we provide an updated understanding of the critical mechanisms behind the anticancer immunity mediated by Treg cells plasticity, the role of IL-35, and tactics to strengthen the immune response against malignancies, outlining major clinical trials that used Treg cells/IL-35 therapies in the three main cancer types (lung, breast, and colorectal cancers).

Latexin (LXN) enhances tumor immune surveillance in mice by inhibiting Treg cells through the macrophage exosome pathway

Latexin (LXN) is a secreted protein with a molecular weight of 29 KD, which is considered a tumor suppressor and plays an important role in the inflammatory immune response. LXN is highly expressed in macrophages and regulates macrophage polarity and tumor immune escape, demonstrating excellent clinical potential. However, its mechanism is still unclear. In this study, a macrophage-T cell co-culture system is established to clarify the secretion of macrophage LXN into the extracellular through exosomes. The results indicate that LXN in macrophage-derived exosomes is functional, that is, LXN-enriched exosome inhibits CD4+T cell differentiation into Treg cells in vitro and in vivo, and exhibits good tumor suppressive effects. Based on this discovery, a biomimetic nanoparticle loaded with LXN protein (MØ@LXN-NPS) is designed and synthesized. Furthermore, the MØ@LXN-NPS shows excellent performance in both in vivo and in vitro, especially in enhancing tumor immune surveillance by inhibiting Treg cells in tumor microenvironment, thus exhibiting excellent anti-tumor activity. This study provides a demonstration for the transition of biomolecules from functional research to engineering applications. The excellent performance of MØ@LXN-NPS in tumor immune regulation suggests that the engineered biomimetic nanomedicine has good clinical application prospects.

Regulatory T Cell- and Natural Killer Cell-Mediated Inflammation, Cerebral Vasospasm, and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage-A Systematic Review and Meta-Analysis Approach

Aneurysmal subarachnoid hemorrhage (SAH) involves a significant influx of blood into the cerebrospinal fluid, representing a severe form of stroke. Despite advancements in aneurysm closure and neuro-intensive care, outcomes remain impaired due to cerebral vasospasm and delayed cerebral ischemia (DCI). Previous pharmacological therapies have not successfully reduced DCI while improving overall outcomes. As a result, significant efforts are underway to better understand the cellular and molecular mechanisms involved. This review focuses on the activation and effects of immune cells after SAH and their interactions with neurotoxic and vasoactive substances as well as inflammatory mediators. Particular attention is given to clinical studies highlighting the roles of natural killer (NK) cells and regulatory T cells (Treg) cells. Alongside microglia, astrocytes, and oligodendrocytes, NK cells and Treg cells are key contributors to the inflammatory cascade following SAH. Their involvement in modulating the neuro-inflammatory response, vasospasm, and DCI underscores their potential as therapeutic targets and prognostic markers in the post-SAH recovery process. We conducted a systematic review on T cell- and natural killer cell-mediated inflammation and their roles in cerebral vasospasm and delayed cerebral ischemia. We conducted a meta-analysis to evaluate outcomes and mortality in studies focused on NK cell- and T cell-mediated mechanisms.

Real-world of Limosilactobacillus reuteri in mitigation of acute experimental colitis

Probiotics have been proposed as a potential strategy for managing ulcerative colitis (UC). However, the underlying mechanisms mediating microbiota-host crosstalk remain largely elusive. Here, we report that Limosilactobacillus reuteri (L. reuteri), as a probiotic, secretes cytoplasmic membrane vesicles (CMVs) that communicate with host cells, alter host physiology, and alleviate dextran sulfate sodium (DSS)-induced colitis. First, L. reuteri-CMVs selectively promoted the proliferation of the beneficial bacterium Akkermansia muciniphila (AKK) by upregulating the expression of glycosidases (beta-N-acetylhexosaminidase and alpha-N-acetylglucosaminidase) involved in glycan degradation and metabolic pathways and restored the disrupted gut microbiota balance. Second, L. reuteri-CMVs were taken up by intestinal epithelial cells (IECs), elevated the expression of ZO-1, E-cadherin (Cdh1), and Occludin (Ocln), decreased intestinal permeability, and exerted protective effects on epithelial tight junction functionality. RNA sequencing analysis demonstrated that L. reuteri-CMVs repaired intestinal barrier by activating the HIF-1 signaling pathway and upregulating HMOX1 expression. Third, L. reuteri-CMVs increased the population of double positive (DP) CD4+CD8+ T cells in the intestinal epithelial layer, suppressing gut inflammation and maintaining gut mucosal homeostasis. Finally, L. reuteri-CMVs exhibited satisfactory stability and safety in the gastrointestinal tract and specifically targeted the desired sites in colitis mice. Collectively, these findings shed light on how L. reuteri interact with the host in colitis, and provide new insights into potential strategies for alleviating colitis.

Protocol for a first-in-human feasibility study of T regulatory cells (TR004) for inflammatory bowel disease using (ex vivo) Treg expansion (TRIBUTE)

INTRODUCTION

Crohn's disease (CD) is a chronic, immune-mediated inflammatory bowel disease (IBD), presenting with symptoms of abdominal pain and bleeding from the gastrointestinal tract. There is no known cure. In vitro-expanded 'thymus-derived' regulatory T cells (tTreg) have shown promise in preclinical models of IBD, leading to interest in their use as a potential therapy in CD. We present a study protocol for a first-in-human study of Tregs for IBD using ex vivo Treg expansion. This study will explore the preliminary safety and tolerability of a single dose of Treg immunotherapy and will inform the design of a subsequent larger trial.

METHODS AND ANALYSIS

Four patients will be recruited from gastroenterology clinics at Guy's and St Thomas' NHS Foundation Trust. Eligible participants are those who are at least 18 years old, have a diagnosis of active moderate to severe CD and have failed to respond to or tolerate at least two prior lines of standard medication. Participants receive a single dose of autologous ex vivo-expanded Tregs and will be followed up to week 21 to collect safety and exploratory efficacy data. Additional safety monitoring will occur at 1 and 2 years post-dose. The primary endpoint is defined as the occurrence of dose-limiting toxicity occurring within 5 weeks post-infusion.

ETHICS AND DISSEMINATION

The study protocol and related documents have been approved by a NHS Research Ethics Committee, the Health Research Authority and the Medicines and Healthcare products Regulatory Agency for Clinical Trial Authorisation. It is intended that the results of the trial will be presented at international conferences and will be submitted for publication in a peer-reviewed scientific journal.

TRIAL REGISTRATION NUMBER

NCT03185000.

Hypoxia signature derived from tumor-associated endothelial cells predict prognosis in gastric cancer

Background

A hypoxic metabolism environment in the tumors is often associated with poor prognostic events such as tumor progression and treatment resistance. In gastric cancer, the mechanism of how hypoxia metabolism affects the tumor microenvironment and immunotherapy efficacy remains to be elucidated.

Methods

We used the bulk-mapping method to analyze the signatures correlated with the response of immunotherapy in the single-cell dataset. Cellular, pathway, and gene were systematically analyzed in both single-cell and bulk validation datasets.

Results

The most significant cell proportion difference between the response and non-response groups was in endothelial cells, which represent the malignant cells. VWF was specifically overexpressed in endothelial cells and was the hub gene of differential genes. EPAS1 was a VWF trans-regulated gene and highly positively correlated with VWF in expression. Knockdown experiments demonstrated that siVWF reduced the expression of VWF, EPAS1, and HIF1A, as well as the synthesis of lactate and adenosine which are indicators of hypoxic metabolism. These results suggest that the overexpression of core malign endothelial genes such as VWF drives hypoxic metabolism in tumors and creates an immunosuppressive environment that reduces the efficacy of immunotherapy. The adverse prognosis of the hypoxia signature was validated in the bulk cohort and significance was further enhanced after selecting core genes and combined survival weight scoring.

Conclusion

In summary, high expression of the malignant endothelial cell driver genes VWF and EPAS1 enhances hypoxic metabolism, and malignant cell-immune cell interactions suppress the immune response. Therefore, the two core genes of hypoxic metabolism might represent potential therapeutic and predicting biomarkers for immunotherapy of gastric cancer in the future.

Genetic insight into dissecting the immunophenotypes and inflammatory profiles in the pathogenesis of Sjogren syndrome

BACKGROUND

Sjogren syndrome (SS) is a chronic systemic autoimmune disease and its pathogenesis often involves the participation of numerous immune cells and inflammatory factors. Despite increased researches and studies recently focusing on this area, it remains to be fully elucidated. We decide to incorporate genetic insight into investigation of the causal link between various immune cells, inflammatory factors and pathogenesis of Sjogren syndrome (SS).

METHODS

Our study leveraged the genetic variants of multi-omics statistics extracted from genome-wide association study (GWAS), the University of Bristol and the FinnGen study. We performed a bidirectional Mendelian randomization and mediation study based on randomly allocated instrumental variables to infer causality, followed by external validation with UK Biobank data and Bayesian colocalization.

RESULTS

We demonstrated that an elevated level of CD27 on IgD + CD24 + B cell, a subset of B cells expressing both IgD and CD24, was associated with a higher risk of SS (OR = 1.119, 95% CI: 1.061-1.179, P < 0.001), while CD3 on CD45RA + CD4 + Treg was a protective factor (OR = 0.917, 95%CI: 0.877-0.959, P < 0.001). Results of meta-analysis and colocalization further supported the significant results identified in the primary analysis. A total of 4 inflammatory cytokines and 7 circulating proteins exhibited potential causal relationships with SS despite no significant result achieved after FDR correction. Finally, results of mediation analysis indicated that CD40L receptor levels had significant mediating effects (β = 0.0314, 95% CI: 0.0004-0.0624, P = 0.0471) at a mediation proportion of 28% (95% CI: 0.364%-55.6%) in causal relationship between CD27 on IgD + CD24 + B cell and SS.

CONCLUSIONS

By providing a novel genetic insight into unveiling the roles of autoimmunity and inflammation in Sjogren syndrome, our findings may potentially lead to identifying new clinical biomarkers for disease monitoring and therapeutic targets that offer more effective alternatives for treating this condition. Therefore, our study may provide valuable evidence for future clinical intervention and targeted immunotherapy.

Spatial and single-cell transcriptomics reveal cellular heterogeneity and a novel cancer-promoting Treg cell subset in human clear-cell renal cell carcinoma

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) is the most common histologic type of RCC. However, the spatial and functional heterogeneity of immunosuppressive cells and the mechanisms by which their interactions promote immunosuppression in the ccRCC have not been thoroughly investigated.

METHODS

To further investigate the cellular and regional heterogeneity of ccRCC, we analyzed single-cell and spatial transcriptome RNA sequencing data from four patients, which were obtained from samples from multiple regions, including the tumor core, tumor-normal interface, and distal normal tissue. On the basis, the findings were investigated in vitro using tissue and blood samples from 15 patients with ccRCC and validated in the broader samples on tissue microarrays.

RESULTS

In this study, we revealed previously unreported subsets of both stromal and immune cells, as well as mapped their spatial location at finer resolution. In addition, we validated the clusters of tumor cells after removing batch effects according to six characterized gene sets, including epithelial-mesenchymal transitionhigh clusters, metastatic clusters and proximal tubulehigh clusters. Importantly, we identified a special regulatory T (Treg) cell subpopulation that has the molecular characteristics of terminal effector Treg cells but expresses multiple cytokines, such as interleukin (IL)-1β and IL-18. This group of Treg cells has stronger immunosuppressive function and was associated with a worse prognosis in ccRCC cohorts. They were colocalized with MRC1 + FOLR2 + tumor-associated macrophages (TAMs) at the tumor-normal interface to form a positive feedback loop, maintaining a synergistic procarcinogenic effect. In addition, we traced the origin of IL-1β+ Treg cells and revealed that IL-18 can induce the expression of IL-1β in Treg cells via the ERK/NF-κB pathway.

CONCLUSIONS

We demonstrated a novel cancer-promoting Treg cell subset and its interactions with MRC1 + FOLR2 +TAMs, which provides new insight into Treg cell heterogeneity and potential therapeutic targets for ccRCC.

Advancing immunosuppression in liver transplantation: the role of regulatory T cells in immune modulation and graft tolerance

Prolonged immunosuppressive therapy in liver transplantation (LT) is associated with significant adverse effects, such as nephrotoxicity, metabolic complications, and heightened risk of infection or malignancy. Regulatory T cells (Tregs) represent a promising target for inducing immune tolerance in LT, with the potential to reduce or eliminate the need for life-long immunosuppression. This review summarizes current knowledge on the roles of Tregs in LT, highlighting their mechanisms and the impact of various immunosuppressive agents on Treg stability and function. The liver's distinct immunological microenvironment, characterized by tolerogenic antigen-presenting cells and high levels of interleukin (IL)-10 and transforming growth factor-β, positions this organ as an ideal setting for Treg-mediated tolerance. We discuss Treg dynamics in LT, their association with rejection risk, and their utility as biomarkers of transplant outcomes. Emerging strategies, including the use of low-dose calcineurin inhibitors with mammalian target of rapamycin inhibitors, adoptive Treg therapy, and low-dose IL-2, aim to enhance Treg function while providing sufficient immunosuppression. Thus, the future of LT involves precision medicine approaches that integrate Treg monitoring with tailored immunosuppressive protocols to optimize long-term outcomes for LT recipients.

MOICS, a novel classier deciphering immune heterogeneity and aid precise management of clear cell renal cell carcinoma at multiomics level

Recent studies have indicated that the tumor immune microenvironment plays a pivotal role in the initiation and progression of clear cell renal cell carcinoma (ccRCC). However, the characteristics and heterogeneity of tumor immunity in ccRCC, particularly at the multiomics level, remain poorly understood. We analyzed immune multiomics datasets to perform a consensus cluster analysis and validate the clustering results across multiple internal and external ccRCC datasets; and identified two distinctive immune phenotypes of ccRCC, which we named multiomics immune-based cancer subtype 1 (MOICS1) and subtype 2 (MOICS2). The former, MOICS1, is characterized by an immune-hot phenotype with poor clinical outcomes, marked by significant proliferation of CD4+ and CD8+ T cells, fibroblasts, and high levels of immune inhibitory signatures; the latter, MOICS2, exhibits an immune-cold phenotype with favorable clinical characteristics, characterized by robust immune activity and high infiltration of endothelial cells and immune stimulatory signatures. Besides, a significant negative correlation between immune infiltration and angiogenesis were identified. We further explored the mechanisms underlying these differences, revealing that negatively regulated endopeptidase activity, activated cornification, and neutrophil degranulation may promote an immune-deficient phenotype, whereas enhanced monocyte recruitment could ameliorate this deficiency. Additionally, significant differences were observed in the genomic landscapes between the subtypes: MOICS1 exhibited mutations in TTN, BAP1, SETD2, MTOR, MUC16, CSMD3, and AKAP9, while MOICS2 was characterized by notable alterations in the TGF-β pathway. Overall, our work demonstrates that multi-immune omics remodeling analysis enhances the understanding of the immune heterogeneity in ccRCC and supports precise patient management.

A novel technique for heart-thymus en bloc transplantation in nonhuman primates

The thymus is a rich source of regulatory T cells and plays a role in self-tolerance. Therefore, transplantation of a vascularized donor thymus may facilitate the induction of tolerance in recipients of a cotransplanted heart allograft. To investigate this hypothesis, we developed a new technique to procure the heart and thymus en bloc from juvenile donors and transplant the composite allograft into thymectomized recipients. Thymic function was monitored by serial biopsy and flow cytometry of peripheral blood. Heart-thymus en bloc transplantation resulted in immediate revascularization of the heart and donor thymus with maintenance of normal thymic architecture, even in biopsies taken months after transplantation. Heart-thymus en bloc transplantation requires minimal modification to current heart procurement techniques. Here, we describe the details of the preparation, procurement, transplantation, and postoperative monitoring for this model, with the intention that this technique could be implemented by other investigators to study the effects of heart and thymus cotransplantation. This method could ultimately offer a new approach to tolerance induction in children.

Immune dysregulation as a driver of bronchiolitis obliterans

Bronchiolitis obliterans (BO) is a disease characterized by airway obstruction and fibrosis that can occur in all age groups. Bronchiolitis obliterans syndrome (BOS) is a clinical manifestation of BO in patients who have undergone lung transplantation or hematopoietic stem cell transplantation. Persistent inflammation and fibrosis of small airways make the disease irreversible, eventually leading to lung failure. The pathogenesis of BO is not entirely clear, but immune disorders are commonly involved, with various immune cells playing complex roles in different BO subtypes. Accordingly, the US Food and Drug Administration (FDA) has recently approved several new drugs that can alleviate chronic graft-versus-host disease (cGVHD) by regulating the function of immune cells, some of which have efficacy specifically with cGVHD-BOS. In this review, we will discuss the roles of different immune cells in BO/BOS, and introduce the latest drugs targeting various immune cells as the main target. This study emphasizes that immune dysfunction is an important driving factor in its pathophysiology. A better understanding of the role of the immune system in BO will enable the development of targeted immunotherapies to effectively delay or even reverse this condition.

Impact of T cell characteristics on CAR-T cell therapy in hematological malignancies

Chimeric antigen receptor (CAR) T-cell therapy has revolutionized the treatment paradigms for hematological malignancies. However, more than half of these patients cannot achieve sustainable tumor control, partially due to the inadequate potency of CAR-T cells in eradicating tumor cells. T cells are crucial components of the anti-tumor immune response, and multiple intrinsic T-cell features significantly influence the outcomes of CAR-T cell therapy. Herein, we review progressing research on T-cell characteristics that impact the effectiveness of CAR-T cells, including T-cell exhaustion, memory subsets, senescence, regulatory T-cells, the CD4+ to CD8+ T-cell ratio, metabolism, and the T-cell receptor repertoire. With comprehensive insight into the biological processes underlying successful CAR-T cell therapy, we will further refine the applications of these novel therapeutic modalities, and enhance their efficacy and safety for patients.

Balancing functions of regulatory T cells in mosquito-borne viral infections

Mosquito-borne viral infections are on the rise worldwide and can lead to severe symptoms such as haemorrhage, encephalitis, arthritis or microcephaly. A protective immune response following mosquito-borne viral infections requires the generation of a controlled and balanced immune response leading to viral clearance without immunopathology. Here, regulatory T cells play a central role in restoring immune homeostasis. In current review, we aim to provide an overview and summary of the phenotypes of FOXP3+ Tregs in various mosquito-borne arboviral disease, their association with disease severity and their functional characteristics. Furthermore, we discuss the role of cytokines and Tregs in the immunopathogenesis of mosquito-borne infections. Lastly, we discuss possible novel lines of research which could provide additional insight into the role of Tregs in mosquito-borne viral infections in order to develop novel therapeutic approaches or vaccination strategies.

The Potential Role of Dietary Polyphenols in the Prevention and Treatment of Acute Leukemia

Acute leukemia is a prevalent cancer worldwide and is classified into two distinct forms. Currently, various therapies have been developed for this disease; however, the issues of recurrence, resistance to treatment, and adverse effects require the exploration of novel treatments. Polyphenols, classified into four categories, are secondary metabolites originating from plants that demonstrate diverse metabolic features such as anticancer, anti-inflammatory, and antioxidant activities. Consequently, they have attracted attention for therapeutic and preventive measures. Research indicates that dietary polyphenols can mitigate the disease burden of acute leukemias by influencing the molecular pathways associated with the disease and its inflammatory processes. Furthermore, owing to their antioxidant properties, they can reduce the amounts of reactive oxygen species generated from the disrupted molecular pathways in these malignancies. The therapeutic actions of polyphenols can facilitate disease recovery by interrupting the cell cycle and causing apoptosis by activating pro-apoptotic genes. In conclusion, the intake of dietary polyphenols, due to their convenience and availability, coupled with the positive outcomes associated with their use in conjunction with conventional therapies, may function as an efficient therapeutic and preventive measure for acute leukemia.

Multi-omics analysis of Prolyl 3-hydroxylase 1 as a prognostic biomarker for immune infiltration in ccRCC

The formation of human collagen requires the presence of Prolyl 3-hydroxylase 1 (P3H1), but the regulatory mechanism of P3H1 remained insufficiently understood. Our study aimed to identify the role of P3H1 in clear cell renal cell carcinoma (ccRCC). P3H1 expression in ccRCC was validated using multiple databases and in vitro experiments. We performed a correlation analysis of P3H1 with drug sensitivity, immune checkpoints, and immune cell infiltration using transcriptome and single-cell sequencing. Drawing upon the Encyclopedia of RNA Interactomes database, we selected P3H1 as the focal point of our investigation, meticulously uncovering the intricate network of microRNAs and lncRNAs that potentially orchestrate ceRNA mechanisms. This study employs a multidimensional approach integrating vitro assays and multi-omics bioinformatics analyses to investigate P3H1's impact on ccRCC prognosis, immune modulation, immune checkpoints, ceRNA regulatory network, drug sensitivity, and therapeutic responses, aiming to uncover new insights into its therapeutic potential and inform future clinical strategies.

Gut microbiota and autoimmune diseases: Insights from Mendelian randomization

In recent years, the scientific community has shown interest in the role of gut microbiota in the development of autoimmune diseases (AID). Although observational studies have revealed significant associations between gut microbiota and AID like rheumatoid arthritis, systemic lupus erythematosus, and multiple sclerosis, these connections do not necessarily imply causality. Mendelian randomization (MR) approach has been extensively employed to investigate the causal relationship. Relevant MR study findings indicate that a reduction in beneficial microbial populations, particularly Bifidobacterium and Lactobacillus, and an increase in potential pathogenic microbes, is correlated with an elevated AID risk. Given the innovative potential of MR in unraveling the etiopathogenesis of AIDs, this article offers an overview of this methodological approach and its recent applications in AID research.

Analysis of Inflammatory and Regulatory Cytokines in the Milk of Dairy Cows with Mastitis: A Comparative Study with Healthy Animals

Bovine mastitis remains a major problem in the global dairy cattle industry. The acute invasion of udder by pathogens induces innate immune response as the first defence mechanism in subclinical and clinical mastitis. The aim of the study was to determine inflammatory and regulatory cytokines IL-2, IL-4, TGF-β1, IL-17A, beta-defensin 3 and IL-10 and their potential changes in milk of dairy cows with subclinical and clinical mastitis, and to compare the findings with healthy animals. Milk samples from 15 holstein Friesian breed cows were used in the study. Cows were divided into three groups based on their health status (5 healthy, 5 subclinical and 5 clinical animals). All samples were tested using immunohistochemistry to evaluate IL-2, IL-4, IL-10, IL17A, TGF-β1 and β-Def 3 proteins. Expression of all proteins was detected in all milk samples. High expression of IL-2, IL-4, IL17A, TGF-β1 was detected in healthy cows' milk and in milk of cows with subclinical and clinical mastitis. However, expression of IL-10 and β-Def 3 in milk samples of healthy cows was significantly higher compared to the milk of cows with subclinical and clinical mastitis (p < .001). IL-10 and β-Def 3 can be considered as informative biomarkers in diagnosis of subclinical and clinical mastitis.

Causal Relationships Between Gut Microbiota, Inflammatory Cells/Proteins, and Subarachnoid Hemorrhage: A Multi-omics Bidirectional Mendelian Randomization Study and Meta-analysis

Subarachnoid hemorrhage (SAH) is a neurological emergency that can lead to fatal outcomes. It occurs when bleeding happens in the subarachnoid space, a small gap between the arachnoid and pia mater. This condition results from the rupture of diseased or damaged blood vessels at the brain's base or surface. This study combined various omics approaches with Mendelian randomization analysis, including MR-IVW, MR Egger, MR weight median, and MR weight mode, to generate preliminary results. It also employed reverse Mendelian randomization, treating SAH as the exposure. Finally, a meta-analysis was conducted to summarize these findings. The study found positive correlations between SAH and both GBPA-Pyridoxal 5 phosphate biosynthesis I (OR=1.48, 95% CI, 1.04-2.12) and GBPA-glucose biosynthesis I (OR=0.68, 95% CI, 0.52-0.90). Increased levels of urokinase-type plasma activator were also associated with SAH (OR=1.17, 95% CI, 1.04-1.32). Associations were observed with SAH for CD80 on CD62L+ plasmacytoid dendritic cells, CD80 on plasmacytoid dendritic cells, CD123 on CD62L+ plasmacytoid dendritic cells, and SSC-A on plasmacytoid dendritic cells. This study, through Mendelian randomization and meta-analysis, established links between SAH and four inflammatory cells, one inflammatory protein, and two gut microbiota-related pathways. These findings suggest potential treatment targets for SAH, highlighting the importance of modulating gut microbiota and utilizing anti-inflammatory drugs in its management.

Decoding the role of FOXP3 in esophageal cancer: Underlying mechanisms and therapeutic implications

Esophageal cancer is a significant contributor to cancer-related mortality, and its poor prognosis is primarily attributed to the aggressive nature of the tumor and challenges in early detection. Currently, there are no ideal drugs developed for treatment, making it crucial to explore potential biomarkers and molecular targets for esophageal cancer. FOXP3, as a transcription factor and major regulator of regulatory T cells, not only plays a role in promoting or inhibiting tumor development in various types of cancer cells including esophageal cancer cells but also influences the function of Treg cells by regulating the expression of multiple genes. This paper provides an in-depth discussion on the functional properties, regulatory mechanisms, key signaling pathways, as well as the role and potential application of FOXP3 in treating esophageal cancer. Furthermore, it comprehensively analyzes the complex role of this transcription factor within the tumor immune microenvironment with an aim to aid in developing new potential targets for esophageal cancer treatment.

Decoding mutational hotspots in human disease through the gene modules governing thymic regulatory T cells

Computational strategies to extract meaningful biological information from multiomics data are in great demand for effective clinical use, particularly in complex immune-mediated disorders. Regulatory T cells (Tregs) are essential for immune homeostasis and self-tolerance, controlling inflammatory and autoimmune processes in many diseases with a multigenic basis. Here, we quantify the Transcription Factor (TF) differential occupancy landscape to uncover the Gene Regulatory Modules governing lineage-committed Tregs in the human thymus, and show that it can be used as a tool to prioritise variants in complex diseases. We combined RNA-seq and ATAC-seq and generated a matrix of differential TF binding to genes differentially expressed in Tregs, in contrast to their counterpart conventional CD4 single-positive thymocytes. The gene loci of both established and novel genetic interactions uncovered by the Gene Regulatory Modules were significantly enriched in rare variants carried by patients with common variable immunodeficiency, here used as a model of polygenic-based disease with severe inflammatory and autoimmune manifestations. The Gene Regulatory Modules controlling the Treg signature can, therefore, be a valuable resource for variant classification, and to uncover new therapeutic targets. Overall, our strategy can also be applied in other biological processes of interest to decipher mutational hotspots in individual genomes.

The CALR mutations enhance the expression of the immunosuppressive proteins GARP and LAP on peripheral blood lymphocytes through increased binding of activated platelets

Recently, an antibody which inhibits the glycoprotein A repetitions predominant (GARP)-mediated release of active transforming growth factor beta (TGFβ) from the TGFβ propeptide latency-associated peptide (LAP) showed preclinical activity in a murine model of the chronic myeloproliferative neoplasms (MPN). Consequently, we investigated the expression of the immunosuppressive molecules LAP and GARP on peripheral blood lymphocytes from 56 MPN patients and 11 healthy donors (HD). We found that lymphocytes from patients with MPN express higher levels of LAP and GARP with no strong differences found between the different MPN diagnoses. The impact of clinical parameters on the expression of LAP and GARP by lymphocytes showed that patients with calreticulin (CALR)mut MPN have increased expression compared with HD and patients with the Januskinase2 (JAK2) mutation. The fraction of lymphocytes bound to activated platelets (aPLT) strongly correlate to LAP and GARP expression suggesting that it is not the lymphocytes themselves but aPLT, which confer the increased expression of GARP and LAP on MPN patient lymphocytes. Notably, no differences in neither platelet counts nor anti-thrombotic therapy was identified between patients with JAK2- and CALRmut patients. Analysis of platelet gene expression failed to identify differences in expression of relevant genes between JAK2- and CALRmut patients.

Neuroinflammation in amyotrophic lateral sclerosis: pathogenic insights and therapeutic implications

PURPOSE OF REVIEW

Neuroinflammation appears to be an important pathogenic process in amyotrophic lateral sclerosis (ALS). Dysfunction of central immune pathways, including activation of microglia and astrocytes, and peripherally derived immune cells, initiate noncell autonomous inflammatory mechanisms leading to degeneration. Cell autonomous pathways linked to ALS genetic mutations have been recently identified as contributing mechanism for neurodegeneration. The current review provides insights into the pathogenic importance of central and peripheral inflammatory processes in ALS pathogenesis and appraises their potential as therapeutic targets.

RECENT FINDINGS

ALS is a multistep process mediated by a complex interaction of genetic, epigenetic, and environmental factors. Noncell autonomous inflammatory pathways contribute to neurodegeneration in ALS. Activation of microglia and astrocytes, along with central nervous system infiltration of peripherally derived pro-inflammatory innate (NK-cells/monocytes) and adaptive (cell-mediated/humoral) immune cells, are characteristic of ALS. Dysfunction of regulatory T-cells, elevation of pro-inflammatory cytokines and dysbiosis of gut microbiome towards a pro-inflammatory phenotype, have been reported as pathogenic mechanisms in ALS.

SUMMARY

Dysregulation of adaptive and innate immunity is pathogenic in ALS, being associated with greater disease burden, more rapid disease course and reduced survival. Strategies aimed at modulating the pro-inflammatory immune components could be of therapeutic utility.