Treg Cell Infiltration Research Articles

Low-dose IL-2 prevents murine chronic cardiac allograft rejection: Role for IL-2-induced T regulatory cells and exosomes with PD-L1 and CD73

To determine the effects and immunological mechanisms of low-dose interleukin-2 (IL-2) in a murine model of chronic cardiac allograft rejection (BALB/c to C57BL/6) after costimulatory blockade consisting of MR1 (250 μg/ip day 0) and CTLA4-Ig (200 μg/ip day 2), we administered low-dose IL-2 (2000 IU/day) starting on posttransplant day 14 for 3 weeks. T regulatory (Treg) cell infiltration of the grafts was determined by immunohistochemistry; circulating exosomes by western blot and aldehyde bead flow cytometry; antibodies to donor MHC by immunofluorescent staining of donor cells; and antibodies to cardiac self-antigens (myosin, vimentin) by ELISA. We demonstrated that costimulation blockade after allogeneic heart transplantation induced circulating exosomes containing cardiac self-antigens and antibodies to both donor MHC and self-antigens, leading to chronic rejection by day 45. Treatment with low-dose IL-2 prolonged allograft survival (>100 days), prevented chronic rejection, and induced splenic and graft-infiltrating CD4+ CD25+ Foxp3 Treg cells by day 45 and circulating exosomes (Foxp3+) with PD-L1 and CD73. MicroRNA 142, associated with the TGFβ pathway, was significantly downregulated in exosomes from IL-2-treated mice. In conclusion, low-dose IL-2 delays rejection in a murine model of chronic cardiac allograft rejection and also induces graft-infiltrating Tregs and circulating exosomes with immunoregulatory molecules.

Distinct cellular immune profiles in lung adenocarcinoma manifesting as pure ground glass opacity versus solid nodules.

Ground glass opacity featured lung adenocarcinomas (GGO-LUAD) display more indolent biological behavior than solid nodule featured lung adenocarcinomas (SN-LUAD) and have an excellent prognosis. However, the cellular immune characteristics of GGO-LUAD remain poorly understood. Immunohistochemistry technique was performed to stain related immune markers (CD8, CD103, CD20, CD138, CD4, FOXP3, CD68, CD163, PD-1 and PD-L1) and TGF-β from 15 patients with pure GGO-LUAD and 15 patients with SN-LUAD tissue sections (Paired cohort), and then, the related markers with significant differences were verified on 10 patients (Verified cohort) with both pure GGO-LUAD and SN-LUAD. For localization analysis of CD68 + tumor-associated macrophages (TAMs) and FOXP3 + Terg cells in tumor areas, pure GGO-LUAD and SN-LUAD were also stained for simultaneous detection of pan-CK, CD68 and FOXP3 by multiplex immunofluorescence. In the Paired cohort, compared with SN-LUAD, only the infiltration of TAMs and Treg cells was significantly lower in GGO-LUAD. The infiltration of the remaining immune cells including CD8 + T cells, CD4 + T cells, CD103 + T cells, CD20 + B cells and CD138 + Plasma cells in GGO-LUAD, although relatively low, was not significantly different. Meanwhile, the expression of TGF-β was significantly higher in SN-LUAD. And the above results have also been confirmed in the Verified cohort. Moreover, there was no significantly difference in PD-L1 expression in GGO-LUAD compared to SN-LUAD both in the Paired cohort and Verified cohort. GGO-LUAD demonstrates an overall less active immune landscape as compared with SN-LUAD. TAMs and TGF-β may play an important role in the progression of GGO-LUAD. More importantly, PD-L1 expression in GGO-LUAD is comparable to that in SN-LUAD, indicating that there may be other reasons for the insensitivity of GGO-LUAD to immunotherapy.

M6A-Related lncRNA Signature Is Involved in Immunosuppression and Predicts the Patient Prognosis of the Age-Associated Ovarian Cancer.

Background Epithelial ovarian cancers are age-associated diseases, usually diagnosed at an advanced stage. lncRNA has been discovered to interplay with N6-methyladenosine (m6A), working in tandem to promote cancer progression and worsening patient outcomes. This study is aimed at investigating the roles and mechanism of m6A-related lncRNA signature on ovarian cancers. Methods We retrieved TCGA and CGGA sequencing data to identify m6A-related lncRNA signature and constructed an m6A score (MS) using the LASSO algorithm. A clinical nomogram was then established to predict the overall survival of patients. Subsequently, GSEA analyses were conducted to obtain pathways involved. Expression of HLA genes, 28 tumor-infiltrating lymphocyte infiltration, and anticancer cycle were analyzed the immunological differences between high-MS and low-MS groups. Finally, immune checkpoint gene expressions and IC50 of chemotherapeutic drugs were calculated, and CMap was run to identify the potential compounds and their corresponding mechanisms. Results We identified 16 m6A-related lncRNAs and constructed an MS model. The high-MS group showed a poor prognosis. A clinical nomogram consists of MS, and age was constructed and predicted the 1-, 3-, and 5-year survival with high accuracy. GSEA analyses presented downregulated antigen processing and presentation pathways. Immunocyte infiltrating analyses demonstrated that high-MS was associated with high infiltration of Treg cells, macrophages, and low Th1/Th2 rate. Also, high expression of immune checkpoint genes NRP1, TNFSF9, and VSIR was observed in the high-MS group. Finally, the high-MS group also predicted low IC50 of vinorelbine and vorinostat. Conclusion This study constructed a robust prediction model for prognostic management and revealed the cross-talk between m6A and immunosuppression. Besides, the m6A lncRNA signature can predict the chemotherapeutic drug response. These will shed light on the development of novel therapeutic strategies and render survival benefits for ovarian patients.

Comprehensive Analysis of Cuproptosis-Related Genes in Immune Infiltration and Prognosis in Melanoma.

Skin cutaneous melanoma (SKCM, hereafter referred to as melanoma) is the most lethal skin cancer with increasing incidence. Regulated cell death plays an important role in tumorigenesis and serves as an important target for almost all treatment strategies. Cuproptosis is the most recently identified copper-dependent regulated cell death form that relies on mitochondria respiration. However, its role in tumorigenesis remains unknown. The correlation of cuproptosis-related genes with tumor prognosis is far to be understood, either. In the present study, we explored the correlation between cuproptosis-related genes with the prognosis of melanoma by accessing and analyzing a public database and found 11 out 12 genes were upregulated in melanoma tissues and three genes (LIPT1, PDHA1, and SLC31A1) have predictive value for the prognosis. The subgroup of melanoma patients with higher cuproptosis-related gene expression showed longer overall survival than those with lower gene expression. We chose LIPT1 for further exploration. LIPT1 expression was increased in melanoma biopsies and was an independent favorable prognostic indicator for melanoma patients. Moreover, LIPT1 expression was positively correlated with PD-L1 expression and negatively associated with Treg cell infiltration. The melanoma patients with higher LIPT1 expression showed longer overall survival than those with lower LIPT1 expression after receiving immunotherapy, indicating the prognostic predictive value of LIPT1. Finally, a pan-cancer analysis indicated that LIPT1 was differentially expressed in diverse cancers as compared to normal tissues and correlated with the expression of multiple immune checkpoints, especially PD-L1. It could serve as a favorable prognosis indicator in some cancer types. In conclusion, our study demonstrated the prognostic value of cuproptosis-related genes, especially LIPT1, in melanoma, and revealed the correlation between LIPT1 expression and immune infiltration in melanoma, thus providing new clues on the prognostic assessment of melanoma patients and providing a new target for the immunotherapy of melanoma.

Associating transcriptomics data with inflammatory markers to understand tumour microenvironment in hepatocellular carcinoma.

Liver cancer is the fourth leading cause of cancer-related death globally which is estimated to reach more than 1 million deaths a year by 2030. Among liver cancer types, hepatocellular carcinoma (HCC) accounts for approximately 90% of the cases and is known to have a tumour promoting inflammation regardless of its underlying aetiology. However, current promising treatment approaches, such as immunotherapy, are partially effective for most of the patients due to the immunosuppressive nature of the tumour microenvironment (TME). Therefore, there is an urgent need to fully understand TME in HCC and discover new immune markers to eliminate resistance to immunotherapy. We analyse three microarray datasets, using unsupervised and supervised methods, in an effort to discover signature genes. First, univariate, and multivariate, feature selection methods, such as the Boruta algorithm, are applied. Subsequently, an optimisation procedure, which utilises random forest algorithm with three dataset pairs combinations, is performed. The resulting optimal gene sets are then combined and further subjected to network analysis and pathway enrichment analysis so as to obtain information related to their biological relevance. The microarray datasets were analysed via the MCP-counter, CIBERSORT, TIMER, EPIC, and quanTIseq deconvolution methods and an estimation of cell type abundances for each dataset sample were identified. The differences in the cell type abundances, between the adjacent and tumour sample groups, were then assessed using a Wilcoxon Rank Sum test (p-value < 0.05). The optimal gene signature sets, derived from each of the data pairs combination, achieved AUC values ranging from 0.959 to 0.988 in external validation sets using Random Forest model. CLEC1B and PTTG1 genes are retrieved across each optimal set. Among the signature genes, PTTG1, AURKA, and UBE2C genes are found to be involved in the regulation of mitotic sister chromatid separation and anaphase-promoting complex (APC) dependent catabolic process (adjusted p-value < 0.001). Additionally, the application of deconvolution algorithms revealed significant changes in cell type abundances of Regulatory T (Treg) cells, M0 and M1 macrophages, and T CD8+ cells between adjacent and tumour samples. We identified ECM1 gene as a potential immune-related marker acting through immune cell migration and macrophage polarisation. Our results indicate that macrophages, such as M0 macrophage and M1 macrophage cells, undergo significant changes in HCC TME. Moreover, our immune deconvolution approach revealed significant infiltration of Treg cells and M0 macrophages, and a significant decrease in T CD8+ cells and M1 macrophages in tumour samples.

3D Collagen Fiber Concentration Regulates Treg Cell Infiltration in Triple Negative Breast Cancer.

BackgroundTriple negative breast cancer (TNBC) is characterized by poor prognosis and a lack of effective therapeutic agents owing to the absence of biomarkers. A high abundance of tumor-infiltrating regulatory T cells (Tregs) was associated with worse prognosis in malignant disease. Exploring the association between Treg cell infiltration and TNBC will provide new insights for understanding TNBC immunosuppression and may pave the way for developing novel immune-based treatments.Materials and MethodsPatients from TCGA were divided into Treg-high (Treg-H) and Treg-low (Treg-L) groups based on the abundance of Tregs according to CIBERSORT analysis. The association between expression level of Tregs and the clinical characteristics as well as prognosis of breast cancer were evaluated. Next, a Treg-related prognostic model was established after survival-dependent univariate Cox and LASSO regression analysis, companied with an external GEO cohort validation. Then, GO, KEGG and GSEA analyses were performed between the Treg-H and Treg-L groups. Masson and Sirius red/Fast Green staining were applied for ECM characterization. Accordingly, Jurkat T cells were encapsulated in 3D collagen to mimic the ECM microenvironment, and the expression levels of CD4, FOXP3 and CD25 were quantified according to immunofluorescence staining.ResultsThe expression level of Tregs is significantly associated with the clinical characteristics of breast cancer patients, and a high level of Treg cell expression indicates a poor prognosis in TNBC. To further evaluate this, a Treg-related prognostic model was established that accurately predicted outcomes in both TCGA training and GEO validation cohorts of TNBC patients. Subsequently, ECM-associated signaling pathways were identified between the Treg-H and Treg-L groups, indicating the role of ECM in Treg infiltration. Since we found increasing collagen concentrations in TNBC patients with distant migration, we encapsulated Jurkat T cells within a 3D matrix with different collagen concentrations and observed that increasing collagen concentrations promoted the expression of Treg biomarkers, supporting the regulatory role of ECM in Treg infiltration.ConclusionOur results support the association between Treg expression and breast cancer progression as well as prognosis in the TNBC subtype. Moreover, increasing collagen density may promote Treg infiltration, and thus induce an immunosuppressed TME.

Prognostic Significance and Immunological Role of FBXO5 in Human Cancers: A Systematic Pan-Cancer Analysis.

F-box protein 5 (FBXO5), an essential subunit of the ubiquitin protein ligase complex, is increasingly recognized to exhibit important biological effects in regulating tumor occurrence and progression. The present research was intended to systematically investigate the latent roles of FBXO5 in prognosis and immunological function across cancers. Pan-cancer analyses of FBXO5 were performed based upon publicly available online databases, mainly including the Cancer Genome Atlas (TCGA), Genotype-Tissue Expression (GTEx), UCSC Xena, cBioPortal, and ImmuCellAI, revealing the possible relationships between FBXO5 and prognosis, DNA methylation, tumor microenvironment (TME), infiltration of immune cells, immune-related genes, immune checkpoints, tumor mutation burden (TMB), and microsatellite instability (MSI). The results suggested that FBXO5 was expressed at a high level in numerous tumor cell lines with significant upregulation in most cancers as opposed to normal tissues. Of note, elevated expression of FBXO5 was significantly related to an unfavorable prognosis in many cancer types. Furthermore, DNA methylation and TME were confirmed to display evident correlation with the expression of FBXO5 in several malignancies. Moreover, FBXO5 expression was remarkably positively correlated with the levels of infiltrating Treg cells and Tcm cells in most tumors, but negatively correlated with tumor-infiltrating CD8+ T cells, NK/NKT cells, and Th2 cells. Meanwhile, FBXO5 was demonstrated to be co-expressed with the genes encoding immune activating and suppressive factors, chemokines, chemokine receptors, and major histocompatibility complex (MHC). Immune checkpoints, TMB, and MSI were also overtly associated with FBXO5 dysregulation among diverse kinds of cancers. Additionally, the enrichment analyses showed close relationships between FBXO5 expression and the processes related to cell cycle and immune inflammatory response. These findings provided a detailed comprehension of the oncogenic function of FBXO5. Because of its crucial roles in cancer immunity and tumorigenesis, FBXO5 may serve as a novel prognostic indicator and immunotherapeutic target for various malignancies.

Protein Kinase Inhibitor-Mediated Immunoprophylactic and Immunotherapeutic Control of Colon Cancer.

Immunotherapy has allowed major advances in oncology in the past years, in particular with the development of immune checkpoint inhibitors, but the clinical benefits are still limited, particularly in colorectal cancer (CRC). Our scientific approach is based on the search for innovative immunotherapy with a final goal that aims to induce an effective antitumor immune response in CRC. Here, we focused on a multikinase inhibitor, H89. We carried out in vivo experiments based on syngeneic mouse models of colon cancer in BALB/c mice and chemically colon tumorigenesis. Flow cytometry, RNAseq, RT-qPCR, antibody-specific immune cell depletion, and Western blot were used to identify the immune cell type involved in the preventive and antitumor activity of H89. We demonstrated that H89 delays colon oncogenesis and prevents tumor growth. This latter effect seems to involve NK cells. H89 also inhibits colon tumor growth in a T-cell-dependent manner. Analysis of the immune landscape in the tumor microenvironment showed an increase of CD4+ Th1 cells and CD8+ cytotoxic T cells but a decrease of CD4+ Treg cell infiltration. Mechanistically, we showed that H89 could promote naïve CD4+ T-cell differentiation into Th1, a decrease in Treg differentiation, and an increase in CD8+ T-cell activation and cytotoxicity ex vivo. Furthermore, H89 induced overexpression of genes involved in antitumor immune response, such as IL-15RA, which depletion counteracts the antitumor effect of H89. We also found that H89 regulated Akt/PP2A pathway axis, involved in TCR and IL-15 signaling transduction. Our findings identify the H89 as a potential strategy for immune system activation leading to the prevention and treatment of CRC.

Physical activity improves outcomes of combined lenvatinib plus anti-PD-1 therapy in unresectable hepatocellular carcinoma: a retrospective study and mouse model

BackgroundPhysical activity is known to have anti-cancer effects, including immunomodulatory actions. This study investigated the hypothesis that physical activity synergizes with combined lenvatinib plus anti-PD-1 therapy to enhance efficacy in patients with unresectable HCC.MethodsThe physical activity levels of patients with unresectable HCC receiving combined lenvatinib plus anti-PD-1 therapy were recorded by questionnaire. Patients were categorized according to physical activity levels (active vs. sedentary). The primary outcome was overall survival (OS). Secondary outcomes included objective response rate (ORR) and progression-free survival (PFS). A subcutaneous syngeneic HCC model was generated in C57BL/6 mice. Mice were randomized to receive placebo, combined lenvatinib plus anti-PD-1 antibodies or combination therapy plus physical activity. Tumors were measured every 3 days and harvested for immunohistochemistry analysis at 20 mm maximum diameter.ResultsFifty-nine patients with unresectable HCC were categorized to active (n = 28) or sedentary (n = 31) groups. The active group had higher albumin and des-γ-carboxy prothrombin levels and lower hepatitis B virus load at baseline; other clinical and oncologic characteristics were comparable between the two groups. Patients in the active group had significantly longer OS (HR = 0.220, 95% CI 0.060–0.799) and PFS (HR = 0.158, 95% CI 0.044–0.562) and higher ORR (OR = 4.571, 95% CI 1.482–14.102) than patients in the sedentary group. Regular physical activity was independently associated with OS, PFS and ORR. The mouse model showed that physical activity significantly suppressed tumor growth and prolonged survival of tumor-bearing mice. Furthermore, physical activity inhibited Treg cell infiltration and immune checkpoint expression (including CTLA4, TIGIT and TIM3) induced by long-term combined lenvatinib plus anti-PD-1 therapy, improving efficacy.ConclusionsRegular physical activity was associated with improved outcomes in unresectable HCC receiving combined lenvatinib plus anti-PD-1 therapy. Physical activity may improve therapeutic efficacy by reprograming the tumor microenvironment from an immunosuppressive to immunostimulatory phenotype.

ASF1B is a Promising Prognostic Biomarker and Correlates With Immunotherapy Efficacy in Hepatocellular Carcinoma.

Background: Anti-silencing function 1B (ASF1B), a histone H3-H4 chaperone, is crucial for S-phase progression and cell proliferation. Recent studies have shown that ASF1B may be used as a new proliferation marker for cancer prognosis. However, the prognostic value and effect of ASF1B on tumor cells and the immune microenvironment in hepatocellular carcinoma (HCC) remain unclear. Methods: We analyzed the expression of ASF1B and its prognostic value using The Cancer Genome Atlas (TCGA) database (as a training set) and other databases, and we validated the findings by immunohistochemistry in our clinical database, containing 141 HCC patients (as a validation set). Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were performed to probe the tumor-associated biological processes of ASF1B in HCC. The interrelationships between ASF1B expression and tumor immunological characteristics were analyzed by multiple databases. The Imvigor210 cohort was retrieved to assess the ability of ASF1B to predict immunotherapy efficacy. Results: ASF1B was highly expressed in tumor tissue compared to paracancerous tissue. High ASF1B expression was associated with worse overall survival (OS) and progression-free survival (PFS) in the training set (p = 0.005, p < 0.001) and validation set (p < 0.001, p < 0.001). Multivariate analysis revealed that ASF1B was an independent prognostic factor associated with OS and PFS. GSEA and GSVA suggested that ASF1B was involved in tumor-associated biological processes, including the cell cycle, DNA replication, base excision repair, mismatch repair, RNA degradation, ubiquitin-mediated proteolysis, and nucleotide excision repair. Further analysis revealed that the levels of ASF1B were positively correlated with the immune cells infiltration of B cells, CD8+ T cells, CD4+ T cells, neutrophils, and dendritic cells. However, ASF1B was positively correlated with Treg cell infiltration and inhibitory immune checkpoints in exhausted T cells. Patients who received anti-PD-L1 immunotherapy with high ASF1B expression had a higher objective response. Conclusion: The ASF1B level is an independent prognostic factor and may serve as a potential immunotherapeutic target.

Dahuang Zhechong pills inhibit liver cancer growth in a mouse model by reversing Treg/Th1 balance.

The infiltration of immune cells into the hepatocellular carcinoma microenvironment is the main reason why hepatocellular carcinoma patients are prone to carcinoma recurrence and the disease are incurable. Notably, the infiltration of Treg cells is the main trigger. Dahuang Zhechong pill (DHZCP) is a traditional Chinese herbal compound successful in the treatment of hepatitis and hepatocellular carcinoma. DHZCP can heal and nourish while slowing the onset of the disease, thereby strengthening the body's immune function. It can localize tumors and ultimately achieve the goal of eliminating tumors. In this study, an orthotopic liver cancer model of mice was used to explore the mechanism of DHZCP enhancing anti-tumor immunity, which showed more Th1 cells in the peripheral blood and spleen after DHZCP treatment, while more IFN-γ was secreted to activate CD8+ T cells and Treg cell production was inhibited, thereby suppressing the growth of HCC. Finally, we also analyzed the potential components of DHZCP from the perspective of modern targets using network pharmacology methods and experimental results.

Pan-Cancer Analysis Predicts FOXS1 as a Key Target in Prognosis and Tumor Immunotherapy.

PurposeOnly a few studies have reported the role of FOXS1, a transcriptional factor, in the tumor development process. In this article, we investigate the function of FOXS1 in distinct neoplastic development and the tumor immune microenvironment (TIME).Patients and MethodsThe latent roles of FOXS1 in various tumors were prospected based on TCGA, GTEx, CCLE, GEPIA2, cBioPortal, TIMER, ImmuCellAI databases, GSVA datasets, GSEA datasets, and R packages. The expression difference, gene alteration, clinical characteristics, prognostic values, biological mechanism, potential pathways, tumor microenvironment, and immune cell infiltration related to FOXS1 were appraised.ResultsFOXS1 was strongly expressed in pan-cancer, and this gene was associated with low survival rates. FOXS1 was linked to many pathways that are cancer-promoting and immune-related. The expression of this transcriptional factor in cancers was positively related to immune cell infiltration, especially M2-like macrophages and Treg cells. In addition to that, FOXS1 demonstrated a positive relationship with many immune-suppression genes, such as TGFB1 and ARORA2A.ConclusionOur study identified an oncogenic effect of FOXS1, which may play a vital role as a prognosticative biological marker in pan-cancer. Exorbitant expression of FOXS1 is associated with high TAMs and Treg cells infiltration. These cells have an immunosuppressive function and promote the development of the immunosuppressive tumor microenvironment. The research of FOXS1 provided a potential drug target for tumor immunotherapy.

Impacts of Cigarette Smoking on the Tumor Immune Microenvironment in Esophageal Squamous Cell Carcinoma.

Objective: Cigarette smoking is a carcinogenic factor for esophageal cancer and evidence also indicates its effects on tumor microenvironment in patients with esophageal squamous cell carcinoma (ESCC).Materials and Methods: In our study, we demonstrated nine immune infiltrating cells and markers in non-smokers and smokers of 189 non-drinking ESCC patients with multiplex fluorescent immunohistochemistry (mflHC) staining and multispectral imaging. The impacts of cigarette smoking on tumor microenvironment and patient prognosis were also analyzed.Results: Among 189 ESCC patients of non-drinker, 86 patients was current smokers, while 34 males and 59 females were non-smokers and 10 former-smokers. Among 34 male non-smokers and 83 smokers, distinct immune infiltrating cells, with increased DCs in stromal regions (P=0.033), elevated infiltration of Treg cells in intraepithelial regions (P=0.010) and reduced activate cytotoxic T lymphocytes (aCTLs) in both intraepithelial (P=0.021) and stromal regions (P=0.017), were observed in tumor specimens of smoking males, implying an immune suppressed response during cigarette smoke exposure. For smoking characters, the level of stromal tumor-associated macrophages (TAMs) infiltration was correlated with smoking year after age adjusted (rs=0.352, P=0.002). Though cigarette smoking did not alter the expression of programmed death ligand 1 (PD-L1) in epithelial cells or TAMs in tumor specimens, higher expression of PD-L1 predicted a worse survival in non-smokers but not smokers.Conclusions: Our findings indicated smoking may impair T cell-mediated immune response and supported the possible impacts of cigarette smoking in PD-L1 related research and therapy of ESCC.

Effects of Signaling Activation of Bone Morphogenetic Protein 2 on the Differentiation and Infiltration of Regulatory T Lymphocytes in Tumors

Objective To determine whether the signaling activation of bone morphogenetic protein 2(BMP2)can induce myeloid-derived suppressor cells(MDSC)to secret transforming growth factor β(TGF-β),further enhancing the differentiation and infiltration of regulatory T lymphocytes(Treg)into tumor tissue. Methods The BMP2-induced mRNA and protein expression of TGF-β in MDSC was detected by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay(ELISA),respectively.The effect of BMP2-induced TGF-β secretion by MDSC on Treg differentiation was then determined by flow cytometry.Finally,we implanted the recombined human bone morphogenetic protein 2(rhBMP2)collagen gels into tumor-burdened mice to examine the role of BMP2 in Treg differentiation via MDSC-secreted TGF-β in vivo.The protein levels of TGF-β in peripheral blood and tumor tissue were detected by ELISA,and the infiltration of Treg cells in tumor tissue was detected by immunofluorescence assay. Results BMP2 up-regulated the mRNA and protein levels of TGF-β in MDSC in vitro.TGF-β secreted by the MDSC exposed to BMP2 treatment could induce the differentiation of Treg cells in vitro.Local implantation of rhBMP2 could increase the level of TGF-β protein in peripheral blood and tumor tissue of mice,further enhancing the infiltration of Treg cells into tumors. Conclusion BMP2 signaling activation can induce the differentiation of Treg cells by promoting the secretion of TGF-β in MDSC,and subsequently promote the infiltration of Treg cells into tumors.

PDAC as an Immune Evasive Disease: Can 3D Model Systems Aid to Tackle This Clinical Problem?

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a high mortality rate. The presence of a dense desmoplastic stroma rich in fibroblasts, extracellular matrix, and immune cells plays a critical role in disease progression, therapy response and is a distinguishing feature of PDAC. PDAC is currently treated with a combination of surgery, chemotherapy and radiation therapy in selected cases which results in long-term survival only in a small percentage of patients. Cancer therapies that incorporate immunotherapy-based techniques have become increasingly common in recent years. While such a strategy has been shown to be effective for immunogenic, “hot” tumors like melanoma and lung cancer, thus far PDAC patients display poor responses to this therapeutic approach. Various factors, such as low tumor mutational burden, increased infiltration of immunosuppressive cells, like MDSCs and Treg cells promote tolerance and immune deviation, further aggravating adaptive immunity in PDAC. In this review we will elaborate on the ability of PDAC tumors to evade immune detection. We will also discuss various 3D model system that can be used as a platform in preclinical research to investigate rational combinations of immunotherapy with chemotherapy or targeted therapy, to prime the immune microenvironment to enhance antitumor activity.

Two novel human anti-CD25 antibodies with antitumor activity inversely related to their affinity and in vitro activity

High tumor regulatory T (Treg) cell infiltration is associated with poor prognosis of many cancers. CD25 is highly expressed on tumor Treg cells and is a potential target for Treg deletion. Previously characterized anti-CD25 antibodies appear to have limited efficacy in tumor inhibition. Here we identified two human anti-CD25 antibodies, BA9 and BT942, which did not prevent the activation of IL-2R signaling pathway by IL-2. BT942 had weaker binding and cytotoxic activity to human CD25-expressing cell lines than BA9. But both demonstrated significant tumor growth inhibition in early and late-stage animal cancer models. BT942 resulted in a higher expansion of CD8+ T cells and CD4+ T cells in tumor microenvironment in mouse MC38 model compared to BA9. BT942 also demonstrated significant higher tumor growth inhibition and higher expansion of CD8+ T cells and CD4+ T cells in combination with an anti-PD1 antibody. Pharmacokinetic study of BT942 in cynomolgus monkeys demonstrated a half-life of 206.97 ± 19.03 h. Structural analysis by cryo-EM revealed that BT942 recognizes an epitope on opposite side of the CD25-IL-2 binding site, consistent with no IL-2 signaling blockade in vitro. BT942 appears to be an excellent candidate for cancer immunotherapy.

Epigenetically associated CCL20 upregulation correlates with esophageal cancer progression and immune disorder

Chemokines have distinct effects on tumor progression by affecting cancer immunity and tumorigenesis. However, the characteristic chemokine profiles and their roles in immune cell recruitment and cancer cell biology are not entirely understood in esophageal cancer. Here, we scrutinized chemokine's expression profiles in independent esophageal cancer cohorts and identified the elevated CCL20 as a risk factor to predict patients' prognosis regardless of histology subtypes. Enhanced CCL20 expression was also associated with the acquisition of metastatic potential. Mechanistically, the upregulation of CCL20 in tumor cells was associated with promoter hypomethylation. Furthermore, by analyzing single-cell RNA sequencing data of a mouse model mimicking human ESCC development, we observed an imbalance among CD4+ T subtypes in the tumor microenvironment, namely Ccr6+ Th17 and Treg cells infiltration alongside the elevated Ccl20 expression in abnormal epithelial cells during the tumorigenic process. Together, these results reveal that hypomethylation-induced CCL20 promotes esophageal cancer progression and immune disorder. Targeting CCL20 might be a promising therapeutic approach in esophageal cancer.

The prognostic value of intratumoral and peritumoral tumor-infiltrating FoxP3+Treg cells in of pancreatic adenocarcinoma: a meta-analysis

BackgroundTumor-infiltrating lymphocytes (TILs) are major participants in the tumor microenvironment. The prognostic value of TILs in patients with pancreatic cancer is still controversial.MethodsThe aim of our meta-analysis was to determine the impact of FoxP3+Treg cells on the survival of pancreatic cancer patients. We searched for related studies in PubMed, EMBASE, Ovid, and Cochrane Library from the time the databases were established to Mar 30, 2017. We identified studies reporting the prognostic value of FoxP3+Treg cells in patients with pancreatic cancer. Overall survival (OS) and disease-free survival (DFS)/progression-free survival (PFS)/relapse-free survival (RFS) were investigated by pooling the data. The pooled hazard ratios (HRs) with 95% confidence intervals (95% CI) were used to evaluate the association between FoxP3+Treg cells and survival outcomes of pancreatic cancer patients. A total of 972 pancreatic cancer patients from 8 studies were included in our meta-analysis.ResultsHigh levels of infiltration with FoxP3+Treg cells were significantly associated with poor OS (HR=2.13; 95% CI 1.64–2.77; P<0.05) and poor DFS/PFS/RFS (HR=1.70; 95% CI 1.04 ~ 2.78; P< 0.05). Similar results were also observed in the peritumoral tissue; high levels of FoxP3+Treg cells were associated with poor OS (HR =2.1795% CI, CI 1.50–3.13).ConclusionThis meta-analysis indicated that high levels of intratumoral or peritumoral FoxP3+Treg cell infiltration could be recognized as a negative factor in the prognosis of pancreatic cancer.

Hydrogel-load exosomes derived from dendritic cells improve cardiac function via Treg cells and the polarization of macrophages following myocardial infarction

BackgroudMyocardial infarction (MI) is one of the leading causes of global death. Dendritic cell-derived exosomes (DEXs) provide us with the possibility of improving cardiac function after MI but are limited by low retention times and short-lived therapeutic effects. In this study, we developed a novel drug delivery system incorporating alginate hydrogel that continuously releases DEXs and investigated the mechanisms underlying the action of DEXs in the improvement of cardiac function after MI.ResultsWe incorporated DEXs with alginate hydrogel (DEXs-Gel) and investigated controlled released ability and rheology, and found that DEXs-Gel release DEXs in a sustainable mammer and prolonged the retention time of DEXs but had no detrimental effects on the migration in vivo. Then DEXs-Gel was applicated in the MI model mice, we found that DEXs-Gel siginificantly enhanced the therapeutic effects of DEXs with regards to improving cardiac function after MI. Flow cytometry and immunofluorescence staining revealed that DEXs significantly upregulated the infiltration of Treg cells and M2 macrophages into the border zoom after MI, and DEXs activated regulatory T (Treg) cells and shifted macrophages to reparative M2 macrophages, both in vitro and in vivo.ConclusionOur novel delivery method provides an innovative tool for enhancing the therapeutic effects of DEXs after MI. Further analysis revealed that DEXs exert effect by activating Treg cells and by modifying the polarization of macrophages.Graphic

Inhibitory Effect of Dihydroartemisinin on the Proliferation and Migration of Melanoma Cells and Experimental Lung Metastasis From Melanoma in Mice.

Melanoma is aggressive and can metastasize in the early stage of tumor. It has been proved that dihydroartemisinin (DHA) positively affects the treatment of tumors and has no apparent toxic and side effects. Our previous research has shown that DHA can suppress the formation of melanoma. However, it remains poorly established how DHA impacts the invasion and metastasis of melanoma. In this study, B16F10 and A375 cell lines and metastatic tumor models will be used to investigate the effects of DHA. The present results demonstrated that DHA inhibited the proliferative capacity in A375 and B16F10 cells. As expected, the migration capacity of A375 and B16F10 cells was also reduced after DHA administration. DHA alleviated the severity and histopathological changes of melanoma in mice. DHA induced expansion of CD8+CTL in the tumor microenvironment. By contrast, DHA inhibited Treg cells infiltration into the tumor microenvironment. DHA enhanced apoptosis of melanoma by regulating FasL expression and Granzyme B secretion in CD8+CTLs. Moreover, DHA impacts STAT3-induced EMT and MMPS in tumor tissue. Furthermore, Metabolomics analysis indicated that PGD2 and EPA significantly increased after DHA administration. In conclusion, DHA inhibited the proliferation, migration and metastasis of melanoma in vitro and in vivo. These results have important implications for the potential use of DHA in the treatment of melanoma in humans.