NEDD9 promotes cancer stemness by recruiting myeloid-derived suppressor cells via CXCL8 in esophageal squamous cell carcinoma

Objective:Esophageal squamous cell carcinoma(ESCC)has high morbidity and mortality rates worldwide.Cancer stem cells(CSCs)may cause tumor initiation,metastasis,and recurrence and are also responsible for chemotherapy and radiotherapy failures.Myeloid-derived suppressor cells(MDSCs),in contrast,are known to be involved in mediating immunosuppression.Here,we aimed to investigate the mechanisms of interaction of CSCs and MDSCs in the tumor microenvironment.Methods:ESCC tissues and cell lines were evaluated.Neural precursor cell expressed,developmentally downregulated 9(NEDD9)was knocked down and overexpressed by lentiviral transfection.Quantitative PCR,Western blot,immunohistochemistry,cell invasion,flow cytometry,cell sorting,multiplex chemokine profiling,and tumor growth analyses were performed.Results:Microarray analysis revealed 10 upregulated genes in esophageal CSCs.Only NEDD9 was upregulated in CSCs using the sphere-forming method.NEDD9 expression was correlated with tumor invasion(P=0.0218),differentiation(P=0.0153),and poor prognosis(P=0.0373).Additionally,NEDD9 was required to maintain the stem-like phenotype.Screening of chemokine expression in ESCC cells with NEDD9 overexpression and knockdown showed that NEDD9 regulated C-X-C motif chemokine ligand 8(CXCL8)expression via the ERK pathway.CXCL8 mediated the recruitment of MDSCs induced by NEDD9 in vitro and in vivo.MDSCs promoted the stemness of ESCC cells through NEDD9 via the Notch pathway.Conclusions:As a marker of ESCC,NEDD9 maintained the stemness of ESCC cells and regulated CXCL8 through the ERK pathway to recruit MDSCs into the tumor,suggesting NEDD9 as a therapeutic target and novel prognostic marker for ESCC.

Emerging roles of myeloid derived suppressor cells in hepatic inflammation and fibrosis

Myeloid derived suppressor cells(MDSC) are a heterogeneous population of immune cells that are potent suppressors of immune responses. MDSC emerge in various compartments in the body, such as blood, bonemarrow or spleen, especially in conditions of cancer, infections or inflammation. MDSC usually express CD11 b, CD33, and low levels of human leukocyte antigen-DR in humans or CD11 b and Gr1(Ly6C/G) in mice, and they can be further divided into granulocytic or monocytic MDSC. The liver is an important organ for MDSC induction and accumulation in hepatic as well as extrahepatic diseases. Different hepatic cells, especially hepatic stellate cells, as well as liver-derived soluble factors, including hepatocyte growth factor and acute phase proteins(SAA, KC), can promote the differentiation of MDSC from myeloid cells. Importantly, hepatic myeloid cells like neutrophils, monocytes and macrophages fulfill essential roles in acute and chronic liver diseases. Recent data from patients with liver diseases and animal models linked MDSC to the pathogenesis of hepatic inflammation, fibrosis and hepatocellular carcinoma(HCC). In settings of acute hepatitis, MDSC can limit immunogenic T cell responses and subsequent tissue injury. In patients with chronic hepatitis C, MDSC increase and may favor viral persistence. Animal models of chronic liver injury, however, have not yet conclusively clarified the involvement of MDSC for hepatic fibrosis. In human HCC and mouse models of liver cancer, MDSC are induced in the tumor environment and suppress anti-tumoral immune responses. Thus, the liver is a primary site of MDSC in vivo, and modulating MDSC functionality might represent a promising novel therapeutic target for liver diseases.

Circulating myeloid-derived suppressor cells in patients with pancreatic cancer

BACKGROUND： Myeloid-derived suppressor cells （MDSCs） are heterogeneous cell types that suppress T-cell responses in cancer patients and animal models, some MDSC subpopulations are increased in patients with pancreatic cancer. The present study was to investigate a specific subset of MDSCs in patients with pancreatic cancer and the mechanism of MDSCs increase in these patients. METHODS： Myeloid cells from whole blood were collected from 37 patients with pancreatic cancer, 17 with cholangiocarcinoma, and 47 healthy controls. Four pancreatic cancer cell lines were co- cultured with normal peripheral blood mononudear cells （PBMCs） to test the effect of tumor cells on the conversion of PBMCs to MDSCs. Levels of granulocyte-macrophage colony-stimulating factor （GM-CSF） and arginase activity in the plasma of cancer patients were analyzed by enzyme-linked immunosorbent assay. RESULTS： CD14＋/CD11b＋/HLA-DR MDSCs were increased in patients with pancreatic or bile duct cancer compared with those in healthy controls, and this increase was correlated with clinical cancer stage. Pancreatic cancer cell lines induced PBMCs to MDSCs in a dose-dependent manner. GM-CSF and arginase activity levels were significantly increased in the se rum of patients with pancreatic cancer. CONCLUSIONS： MDSCs were tumor related： tumor cells induced PBMCs to MDSCs in a dose-dependent manner and circulating CD14＋/CD11b＋/HLA-DR- MDSCs in pancreatic cancer patients were positively correlated with tumor burden. MDSCs might be useful markers for pancreatic cancer detection and progression.

Cyclooxygenase-2 Blockade Inhibits Accumulation and Function of Myeloid-derived Suppressor Cells and Restores T Cell Response after Traumatic Stress

Myeloid-derived suppressor cells （MDSCs） play a crucial role in T cell dysfunction, which is related to poor outcome in patients with severe trauma. Cyclooxygenase-2 （Cox-2） contributes to immune disorder in trauma and infection via production of prostaglandin E2. However, the role of Cox-2 in the accumulation and function of MDSCs after traumatic stress has not been fully elucidated. In the present study, we treated murine trauma model with NS398, a selective Cox-2 inhibitor. Then the percentages of CD1 lb＋/Gr-l＋ cells, proliferation and apoptosis of CD4＋ T cells were determined. Ar- ginase activity and arginase-1 （Arg-1） protein expression of splenic CDllb＋/Gr-I＋ cells, and de- layed-type hypersensitivity （DTH） response were analyzed. The results showed that Cox-2 blockade significantly decreased the percentages of CD1 lb＋/Gr-l＋ cells in the spleen and bone marrow 48 and 72 h after traumatic stress. NS398 inhibited arginase activity and down-regulated the Arg-1 expression of splenic CD1 lb＋/Gr-l＋ ceils. Moreover, NS398 could promote proliferation and inhibit apoptosis of CD4＋ T cells. It also restored DTH response of traumatic mice. Taken together, our data revealed that Cox-2 might play a pivotal role in the accumulation and function of MDSC after traumatic stress.

Changes in the frequency of myeloid-derived suppressor cells after transarterial chemoembolization with gelatin sponge microparticles for hepatocellular carcinoma

Purpose: A series of clinical studies have established the safety and efficacy of transcatheter arterial chemoembolization(TACE) with gelatin sponge microparticles(GSMs) in treating hepatocellular carcinoma(HCC). HCC can lead to obvious necrosis inside tumors, especially larger ones, although it is unclear whether such necrotic tumor tissue can induce favorable immune reactions against the tumor. Myeloid-derived suppressor cells(MDSCs)have immunosuppressive functions and are currently considered a very important cell type affecting tumor immunity. This study observed changes in MDSC frequency in peripheral blood before and after GSM–TACE to evaluate the effect on the immune function of HCC patients.Methods: Eight patients diagnosed with HCC underwent GSM–TACE treatment in the Hepatobiliary Interventional Department of Beijing Tsinghua Chang Gung Hospital, Beijing, China;we followed up with the patients over a period of 30 days post-surgery. We used flow cytometry(FCM) to quantify the frequency of MDSCs in peripheral blood before TACE, 10 days after surgery and 30 days after surgery.Results: MDSC frequency after GSM–TACE had a significant downward trend. Pre-TACE, it was 30.73% ? 11.93%,decreasing to 18.60% ? 11.37% at 10 days after operation. This decrease was not statistically significant(P > 0.05). MDSC frequency was even lower 30 days after TACE(7.63% ? 7.32%) than at 10 days after TACE(P < 0.05), and there was a significant difference compared with pre-TACE(P < 0.001). We evaluated tumor response at 30 days after GSM–TACE according to the Modified Response Evaluation Criteria in Solid Tumors(mRECIST), and all eight patients showed partial response(PR).Conclusion: Our results confirmed that GSM–TACE was beneficial for improving anti-tumor immunity in the treatment of HCC.

Amplification of Functional Myeloid-derived Suppressor Cells during Stem Cell Mobilization Induced by Granulocyte Colony-stimulation-factor

The effects of granulocyte colony-stimulation-factor （G-CSF） on stem cell mobilization and its impact on the amplification of myeloid-derived suppressor cells （MDSCs） of donor mice were ex- amined. A mouse model of stem cell mobilization was established by consecutive subcutaneous injec- tion of 100 μg/kg G-CSF for 5 days. The blood from the donor mice was routinely examined during mobilization. Stem cells and MDSCs were analyzed by flow cytometry. The immunosuppressive mole- cules derived from MDSCs in serum and spleen, including hydrogen dioxide （H202） and nitric oxide （NO）, and the activity of nitric oxide synthase （NOS） were determined during the mobilization. Apop- tosis of T lymphocytes was assessed by using Annexin-V/PI. During stem cell mobilization, the number of lymphocytes and white blood cells in the peripheral blood was increased, and peaked on the 4th day. The number of stem cells in G-CSF-treated mice was significantly greater than that in controls （P〈0.01）. The expansions of MSDCs were also observed after G-CSF mobilization, with a more notable rate of growth in the peripheral blood than in the spleen. The activity of NOS and the production of NO were increased in the donor mice, and the serum H202 levels were approximately 4-fold greater than the con- trois. Consequently, apoptosis of T lymphocytes was increased and showed a positive correlation with the elevated percentage of MDSCs. It was concluded that G-CSF could provide sufficient peripheral blood stem cells for transplantation. Exogenous administration of G-CSF caused the accumulation of MDSCs in the peripheral blood and the spleen, which could lead to apoptosis ofT lymphocytes and may offer a new strategy for the prevention and treatment of graft versus host disease.

Effects of methionine enkephalin on immune enhancement by reducing myeloid derived suppressor cells and reprogramming liver metabolism in colon cancer mice

OBJECTIVE To investigate enhanced immune function of methionine encephalin(MENK)and its anti-tumor mechanism in CT26 colon cancer mouse model.METHODS 3×10~6CT26 cells were implanted subcutaneously in BALB/c mice.Four days after,MENK was peritoneally administrated at the concentration of 20 mg·kg^(-1) for 14 d.The percentage of MDSCs in bone marrow,spleen,blood,tumor and liver were detected by flow cytometry.Non-esterified fatty acid(NEFA),triglycerides(TG)and total cholesterol(T-CHO)in liver homogenate were tested by a NEFA test kit,a TG test kit and a T-CHO test kit respectively.qRT-PCR and Western blot were used to measure m RNA and protein levels of inflammation-,glycometabolsim-and lipometabolsim-associated indexes in liver.RESULTS MENK decreased percentages of MDSCs in bone marrow,spleen,blood and tumor in colon cancer mice.MENK-treated mice displayed elevated ratio of CD4^+T and CD8^+T cells in spleen as well as increased T and B lymphocytes proliferation.Meanwhile,MENK also ameliorated liver damage reflected by lower levels of GPT and GOT in serum and reduced risks of cancer-associated index including inflammation,high lipid and high glucose.Furthermore,MENK lowered down the levels of NEFA,TG and T-CHO in liver homogenate.MENK treatment decreased expression of p-STAT3,increased expression of p-AKT,IRS1 and Glut4 at protein level as well as reduced lipogenesis-associated genes and elevated glycolysis-associated genes in liver of tumor bearing mice.Also,abated expression of genes associated with MDSCs generation(M-CSF,GM-CSF,IL-6,IL^(-1)β)and migration(S100A9,KC)was observed within shrunken subcutaneous tumor by MENK intervention.CONCLUSION MENK has the ability to strength immune function against colon cancer by reducing MDSCs and improving liver metabolism.

GM3-containing nanoparticles in immunosuppressed hosts:Effect on myeloid-derived suppressor cells

Cancer vaccines to date have not broadly achieved a significant impact on the overall survival of patients. The negative effect on the immune system of the tu-mor itself and conventional anti-tumor treatments such as chemotherapy is, undoubtedly, a key reason for these disappointing results. Myeloid-derived suppres-sor cells （MDSCs） are considered a central node of the immunosuppressive network associated with tumors. These cells inhibit the effector function of natural killer and CD8＋ T cells, expand regulatory T cells and can differentiate into tumor-associated macrophages within the tumor microenvironment. Thus, overcoming the suppressive effects of MDSCs is likely to be criti-cal for cancer immunotherapy to generate effective anti-tumor immune responses. However, the capacity of cancer vaccines and particularly their adjuvants to overcome this inhibitory population has not been well characterized. Very small size proteoliposomes （VSSP） is a nanoparticulated adjuvant specifcally designed to be formulated with vaccines used in the treatment of immunocompromised patients. This adjuvant contains immunostimulatory bacterial signals together with GM3 ganglioside. VSSP promotes dendritic cell maturation, antigen cross-presentation to CD8＋ T cells, Th1 polar-ization, and enhances CD8＋ T cell response in tumor-free mice. Currently, four cancer vaccines using VSSP as the adjuvant are in Phase？Ⅰ？and Ⅱ clinical trials. In this review, we summarize our work characterizing the unique ability of VSSP to stimulate antigen-specifc CD8＋ T cell responses in two immunocompromised sce-narios; in tumor-bearing mice and during chemother-apy-induced leukopenia. Particular emphasis has been placed on the interaction of these nanoparticles with MDSCs, as well as comparison with other cancer vac-cine adjuvants currently in preclinical or clinical studies.

维生素D缺乏患者血清25羟维生素D水平与M-MDSCs、TNF-α、IL-10的差异性分析

目的探讨维生素D缺乏患者血清25羟维生素D[25(OH)D]水平与单核细胞型髓源抑制性细胞(M-MDSCs)、肿瘤坏死因子-α(TNF-α)和白细胞介素-10(IL-10)的相关性。方法选取2022年6—9月于银川市第一人民医院就诊的维生素D缺乏症患者24例(维生素D缺乏组)和同期健康体检者24例(正常对照组),收集基础临床指标,采集外周抗凝血,分离外周血浆和血细胞后,提取外周血单个核细胞(PBMCs),采用流式细胞术分析CD45+白细胞和CD45^(+)CD15^(-)CD11b^(+)HLA^(-)DR^(-)CD14^(+)M-MDSCs,采用ELISA法检测外周血清TNF-α、IL-10水平,采用Pearson相关分析探讨血清25(OH)D与M-MDSCs、TNF-α及IL-10的相关性。结果与正常对照组相比,维生素D缺乏组患者外周血白细胞增加、M-MDSCs增高(P均<0.05),血浆中TNF-α水平升高、IL-10降低(P均<0.05)。相关性分析结果显示,25(OH)D与CD45^(+)白细胞、M-MDSCs和TNF-α呈负相关,与IL-10呈正相关(P均<0.05)。结论维生素D缺乏患者25(OH)D水平降低后可促进炎症发生,并与M-MDSCs密切相关。

The protective role of myeloid-derived suppressor cells in concanavalin A-induced hepatic injury

The mechanism underlying T cell-mediated fulminant hepatitis is not fully understood. In this study, we investigated whether myeloid derived suppressor cells （MDSCs） could prevent the concanavalin A （ConA）- induced hepatitis through suppressing T cell proliferation. We observed an increase in the frequencies of MDSCs in mouse spleen and liver at early stage of ConA treatment, implicating that the MDSCs might be involved in the initial resistance of mice against ConA- mediated inflammation. Subpopulation analysis showed that the MDSCs in liver of ConA-induced mice were mainly granulocytic MDSCs. Adoptive transfer of the bone marrow-derived MDSCs into ConA-treated mice showed that the MDSCs migrated into the liver and spleen where they suppressed T cell proliferation through ROS pathway. In addition, the frequencies of MDSCs in mice were also significantly increased by the treatment with immune suppressor glucocorticoids. Transfer of MDSCs into the regulatory T cell （Treg）- depleted mice showed that the protective effect of MDSCs on ConA-induced hepatitis is Treg-independent. In conclusion, our results demonstrate that MDSCs possess a direct protective role in T cell-mediated hepatitis, and increasing the frequency of MDSCs by either adoptive transfer or glucocorticoid treatment represents a potential cell-based therapeutic strategy for the acute inflammatory disease.

白藜芦醇通过诱导G-MDSCs凋亡和M-MDSCs分化延缓Lewis荷瘤小鼠肿瘤生长

目的:探讨白藜芦醇对髓源抑制性细胞(myeloid-derived suppressor cells,MDSCs)的影响及其抗肿瘤免疫的作用。方法:建立小鼠Lewis肺癌移植瘤模型,用白藜芦醇(白藜芦醇组,n=6)和PBS(对照组,n=6)分别灌胃处理,测量肿瘤体积和重量;用流式细胞术检测小鼠体内各群MDSCs细胞比率;用免疫磁珠分选技术分离出荷瘤小鼠脾脏粒系MDSCs(G-MDSCs)及单核系MDSCs(M-MDSCs),经白藜芦醇分别刺激12 h后,流式细胞术检测GMDSCs凋亡及M-MDSCs分化情况。结果:与对照组比较,白藜芦醇组荷瘤小鼠肿瘤体积显著减小(P <0. 05),肿瘤重量减轻(P <0. 01),脾脏中总MDSCs、M-MDSCs比率无明显变化,G-MDSCs比率下调;肿瘤组织中总MDSCs和G-MDSCs比率均显著减少(P均<0. 05),M-MDSCs比率无显著差异。白藜芦醇分别处理G-MDSCs、M-MDSCs后,早期和晚期凋亡的G-MDSCs总数明显高于对照组,M-MDSCs表面CD11c和F4/80的表达显著上调。结论:白藜芦醇可通过促进G-MDSCs凋亡和M-MDSCs分化抑制肿瘤生长。

Contribution of myeloid-derived suppressor cells to tumor-induced immune suppression,angiogenesis,invasion and metastasis

Growing evidence suggests that myeloid-derived suppressor cells （MDSCs）,which have been named ＂immature myeloid cells＂ or ＂myeloid suppressor cells＂ （MSCs）,play a critical role during the progression of cancer in tumor-bearing mice and cancer patients.As their name implies,these cells are derived from bone marrow and have a tremendous potential to suppress immune responses.Recent studies indicated that these cells also have a crucial role in tumor progression.MDSCs can directly incorporate into tumor endothelium.They secret many pro-angiogenic factors as well.In addition,they play an essential role in cancer invasion and metastasis through inducing the production of matrix metalloproteinases （MMPs）,chemoattractants and creating a pre-metastatic environment.Increasing evidence supports the idea that cancer stem cells （CSCs） are responsible for tumorigenesis,resistance to therapies,invasion and metastasis.Here,we hypothesize that CSCs may ＂hijack＂ MDSCs for use as alternative niche cells,leading to the maintenance of stemness and enhanced chemo-and radio-therapy resistance.The countermeasure that directly targets to MDSCs may be useful for against angiogenesis and preventing cancer from invasion and metastasis.Therefore,the study of MDSCs is important to understand tumor progression and to enhance the therapeutic efficacy against cancer.

Hepatic immune tolerance induced by hepatic stellate cells

The liver, which is a metabolic organ, plays a pivotal role in tolerance induction. Hepatic stellate cells(Hp SCs), which are unique non-parenchymal cells, exert potent immunoregulatory activity during cotransplantation with allogeneic islets effectively protecting the islet allografts from rejection. Multiple mechanisms participate in the immune tolerance induced by Hp SCs, including the marked expansion of myeloid-derived suppressor cells(MDSCs), attenuation of effector T cell functions and augmentation of regulatory T cells. Hp SC conditioned MDSC-based immunotherapy has been conducted in mice with autoimmune disease and the results show that this technique may be promising. This article demonstrates how Hp SCs orchestrate both innate immunity and adaptive immunity to build a negative network that leads to immune tolerance.

Hypertonic saline resuscitation contributes to early accumulation of circulating myeloid-derived suppressor cells in a rat model of hemorrhagic shock

Background Hemorrhagic shock is usually associated with complicated immune and inflammatory responses, which are sometimes crucial for the prognosis. As regulators of the immune and inflammatory system; proliferation, migration, distribution and activation of myeloid-derived suppressor cells （MDSCs） are intimately linked to the inflammation cascade. Methods In a model of severe hemorrhagic shock, thirty-five rats were randomly divided into control, sham, normal saline resuscitation （NS）, hypertonic saline resuscitation （HTS）, and hydroxyethyl starch resuscitation （HES）, with seven in each group. MDSCs were analyzed by flow cytometric staining of CD11b/c＊Gra~ in peripheral blood mononuclear cells （PBMC）, spleen cell suspensions, and bone marrow nucleated cells （BMNC）. Simultaneously, the expressions of arginase-1 （ARG-1） and inducible nitric oxide synthase （iNOS） mRNA in MDSCs were evaluated by quantitative reverse transcription-polymerase chain reaction （qRT-PCR）. Results In the early stage after hemorrhagic shock, fluid resuscitation and emergency treatment, the MDSCs in the PBMC of NS, HTS and HES groups markedly increased, and MDSCs in BMNC of these groups decreased accordingly, significantly different to the control group. In hemorrhagic shock rats infused with HTS at the early resuscitation stage, MDSCs in PBMC increased about 2 and 4 folds, and MDSCs in BMNC decreased about 1.3 and 1.6 folds, as compared to the sham group respectively, with statistically significant difference. Furthermore, compared to the NS and HES groups, the MDSCs in PBMC of HTS group increased 1.6 and 1.8 folds with statistically significant differences; the MDSCs decrease in BMNC was not significant. However, there was no statistically significant difference in MDSCs of spleen among the five groups. In addition, compared to the control, sham, NS and HES groups, the ARG-1 and iNOS mRNA of MDSCs in PBMC, spleen and BMNC in the HTS group had the highest level of expression, but no statistically significant differences were noted. Conclusions In this model of rat with severe and controlled hemorrhagic shock, small volume resuscitation with HTS contributes to dramatically early migration and redistribution of MDSCs from bone marrow to peripheral circulation, compared to resuscitation with NS or HES.

Increased circulating of myeloid-derived suppressor cells in myelodysplastic syndrome

Myelodysplastic syndrome （MDS） is a group of clonal .hematopoietic stem cell disorders, characterizedby varying degrees ot peripheral cytopema caused by ineffective dysplasia of the myeloid lineages. MDS also has a high risk of progression to acute myeloid leukemia. But the role of immune abnormalities in the pathogenesis of MDS is still not clear. Myeloid-derived suppressor cells （MDSCs） constitute a heterogeneous population of immature cells derived from the bone marrow. In the recent years, MDSCs were reported to play an important role in suppressing lymphocytes in tumor-bearing animal models and cancer patients. This could be one of the mechanisms on tumor immune evasion, which aggravates the development and growth of tumors. In a mice model, MDSCs are characterized by co- expression of GR1 and CDllb. In humans, the phenotype of MDSCs was accepted as Lin- HLA-DR- CD33＋.l In the present study, we investigated the level of circulating MDSCs （Lin- HLA-DR- CD33＋） in patients with MDS and evaluated the association between MDSCs and malignancy in MDS. METHODS Patients Thirty-five patients with MDS （24 men and 11 women, median age 59 years （age range 21-83）, including refractory anemia （n=3）; refractory anemia with ringed sideroblasts （n=3）; refractory cytopenia with multilineage dysplasia （n=9）; refractory anemia with excess blast-I （n=4）; refractory anemia with excess blast-II （n=16））, and without other systemic diseases, were enrolled in the present study. All the patients underwent diagnosis in the Department of Hematology, General Hospital of Tianjin Medical University from March 2011 to April 2012, according to the diagnostic criteria of MDS proposed between 2007 and 2008. After treatment for three months, 14 MDS patients were investigated again for their MDSCs changes. Twenty normal healthy individuals were selected as controls （9 men and 11 women, median age 34 years （age range 26-82））. The study was approved by the Ethics Committee of Tianjin Medical University. Informed written consent was obtained from all the patients and normalindividuals in accordance with the Declaration of Helsinki Flow cytometric analysis Peripheral blood samples were collected in EDTA- anticoagulant tubes from the patients and normal individuals. The number of circulating MDSCs was measured by using flow cytometry （FCM） assay. The markers used in the assay were anti-CD33-APC, anti-LIN- FITC （CD3, CD14, CD16, CD19, CD20, CD56） and anti- HLA-DR-PE antibodies （BD Biosciences, USA）. The number of stem cells from the bone marrow, which was collected in heparin-anticoagulant tubes, was measured by FCM using anti-CD34-PerCP antibodies （BD Biosciences）. Data acquisition and analysis were carried out by using FACS-Calibur flow cytometer （BD Biosciences）, with the Cell Quest software （Becton Dickinson, version 3.1）.

Engagement of sialylated glycans with Siglec receptors on suppressive myeloid cells inhibits anticancer immunity via CCL2

The overexpression of sialic acids on glycans,called hypersialylation,is a common alteration found in cancer cells.Sialylated glycans can enhance immune evasion by interacting with sialic acid-binding immunoglobulin-like lectin(Siglec)receptors on tumorinfiltrating immune cells.Here,we investigated the effect of sialylated glycans and their interaction with Siglec receptors on myeloid-derived suppressor cells(MDSCs).We found that MDSCs derived from the blood of lung cancer patients and tumor-bearing mice strongly express inhibitory Siglec receptors and are highly sialylated.In murine cancer models of emergency myelopoiesis,Siglec-E knockout in myeloid cells resulted in prolonged survival and increased tumor infiltration of activated T cells.Targeting suppressive myeloid cells by blocking Siglec receptors or desialylation strongly reduced their suppressive potential.We further identified CCL2 as a mediator involved in T-cell suppression upon interaction between sialoglycans and Siglec receptors on MDSCs.Our results demonstrated that sialylated glycans inhibit anticancer immunity by modulating CCL2 expression.

ITP患者M-MDSC表达水平变化对其相关免疫功能的影响

目的:探讨单核细胞型髓系来源抑制性细胞(M-MDSC)在原发性免疫性血小板减少症(ITP)患者中表达水及Arg-1与iNOS的mRNA水平。分选CD4^(+)T细胞、M-MDSC和CD14^(+)HLA-DR^(+)细胞。并以CFSE标记CD4^(+)T细胞,ITP组患者外周血中Arg-1表达水平较对照组未见明显差异(P>0.05),而其iNOS表达水平明显升高(P<0.01)。ITP干扰素。结论:M-MDSC可能与ITP患者体内存在的免疫耐受功能紊乱有关,并可能成为监测ITP患者疗效的新指标。

Personalized cancer vaccines from bacteria-derived outer membrane vesicles with antibody-mediated persistent uptake by dendritic cells

Nanocarriers with intrinsic immune adjuvant properties can activate the innate immune system while delivering tumor antigen,thus efficiently facilitating antitumor adaptive immunity.Bacteria-derived outer membrane vesicles(OMVs)are an excellent candidate due to their abundance of pathogen associated molecular patterns.However,during the uptake of OMVs by dendritic cells(DCs),the interaction between lipopolysaccharide and toll-like receptor 4 induces rapid DC maturation and uptake blockage,a phenomenon we refer to as“maturation-induced uptake obstruction"(MUO).Herein we decorated OMV with the DC-targeting aDEC205 antibody(OMV-DEC),which endowed the nanovaccine with an uptake mechanism termed as 4<not restricted to maturation via antibody modifying”(Normandy),thereby overcoming the MUO phenomenon.We also proved the applicability of this nanovaccine in identifying the human tumor neoantigens through rapid antigen display.In summary,this engineered OMV represents a powerful nanocarrier for personalized cancer vaccines,and this antibody modification strategy provides a reference to remodel the DC uptake pattern in nanocarrier design.

Emergence of immunotherapy as a novel way to treat hepatocellular carcinoma

Tumor immunity proceeds through multiple processes, which consist of antigen presentation by antigen presenting cells(APCs) to educate effector cells and destruction by the effector cytotoxic cells. However, tumor immunity is frequently repressed at tumor sites. Malignantly transformed cells rarely survive the attack by the immune system, but cells that do survive change their phenotypes to reduce their immunogenicity. The resultant cells evade the attack by the immune system and form clinically discernible tumors. Tumor microenvironments simultaneously contain a wide variety of immune suppressive molecules and cells to dampen tumor immunity. Moreover, the liver microenvironment exhibits immune tolerance to reduce aberrant immune responses to massively-exposed antigens via the portal vein, and immune dysfunction is frequently associated with liver cirrhosis, which is widespread in hepatocellular carcinoma(HCC) patients. Immune therapy aims to reduce tumor burden, but it is also expected to prevent non-cancerous liver lesions from progressing to HCC, because HCC develops or recurs from noncancerous liver lesions with chronic inflammatory states and/or cirrhosis and these lesions cannot be cured and/or eradicated by local and/or systemic therapies. Nevertheless, cancer immune therapy should augment specific tumor immunity by using two distinct measures: enhancing the effector cell functions such as antigen presentation capacity of APCs and tumor cell killing capacity of cytotoxic cells, and reactivating the immune system in immune-suppressive tumor microenvironments. Here, we will summarize the current status and discuss the future perspective on immune therapy for HCC.

M-MDSC在非霍奇金淋巴瘤中表达及临床意义

目的探讨单核细胞型髓系来源抑制性细胞(M-MDSC)在非霍奇金淋巴瘤(NHL)患者中的表达水平以及临床意义。方法选取2017年9月至2020年1月解放军第九○一医院和安徽医科大学第二附属医院35例初诊NHL患者作为试验组,同期选取20例健康志愿者作为对照组。比较两组研究对象M-MDSC、精氨酸酶-1(Arg-1)mRNA及诱导型一氧化氮合酶(iNOS)mRNA的表达水平。分析M-MDSC与NHL患者年龄、性别、临床分期、病理分型、乳酸脱氢酶(LDH)以及IPI评分等临床指标的相关性。结果试验组患者M-MDSC表达水平为(32.64±11.23)%,高于对照组,差异有统计学意义(P<0.05)。Ⅲ~Ⅳ期、LDH升高及IPI评分为3~5分的NHL患者,M-MDSC水平升高,差异有统计学意义(P<0.05)。试验组患者Arg-1水平为(18.12±5.25)ng/mL,iNOS mRNA相对水平为(12.36±3.68),均高于对照组,差异有统计学意义(P<0.05)。结论M-MDSC参与NHL患者发病过程,与疾病进展密切相关,可能成为治疗NHL的新靶点。