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.

Lysosomal acid lipase is critical for myeloid-derived suppressive cell differentiation, development, and homeostasis

Lysosomal acid lipase （LAL） cleaves cholesteryl esters （CE） and triglycerides （TG） to generate cholesterol and free fatty acid in lysosomes of cells. The down-stream metabolic products of fatty acids are ligands for activation of peroxisome proliferator-activated re-ceptor gamma （PPARγ）. Accumulation of CEs and TGs is resulted from lack of functional LAL in lysosomes of cells, especially in myeloid cells. One characteristic phenotype in LAL knock-out （ lal-/- ） mice is systemic elevation of myeloid-derived suppressive cells （MDSCs）. MDSCs infltrate into multiple distal organs, alter T cell development, and suppress T cell proliferation and lym-phokine production in lal-/- mice, which lead to severe pathogeneses in multiple organs. The gene transcrip-tional profle analysis in MDSCs from the bone marrow has identified multiple defects responsible for MDSCs malformation and malfunction in lal-/- mice, including G protein signaling, cell cycles, glycolysis metabolism, mitochondrial bioenergetics, mTOR pathway etc. In a sep-arate gene transcriptional profle analysis in the lung of lal-/- mice, matrix metalloproteinase 12 （MMP12） and apoptosis inhibitor 6 （Api6） are highly overexpressed due to lack of ligand synthesis for PPARγ. PPARγ nega-tively regulates MMP12 and Api6. Blocking the PPAR signaling by overexpression of a dominant negative PPARγ （dnPPARγ） form, or overexpressing MMP12 or Api6 in myeloid or lung epithelial cells in inducible transgenic mouse models results in elevated MDSCs and infammation-induced tumorigenesis. These stud-ies demonstrate that LAL and its downstream effectors are critical for MDSCs development, differentiation and malfunction.

Single-cell transcriptome profiling of sepsis identifies HLA-DR^(low)S100A^(high)monocytes with immunosuppressive function

Background Sustained yet intractable immunosuppression is commonly observed in septic patients,resulting in aggravated clinical outcomes.However,due to the substantial heterogeneity within septic patients,precise indicators in deciphering clinical trajectories and immunological alterations for septic patients remain largely lacking.Methods We adopted cross-species,single-cell RNA sequencing(scRNA-seq)analysis based on two published datasets containing circulating immune cell profile of septic patients as well as immune cell atlas of murine model of sepsis.Flow cytometry,laser scanning confocal microscopy(LSCM)imaging and Western blotting were applied to identify the presence of S100A9^(+)monocytes at protein level.To interrogate the immunosuppressive function of this subset,splenic monocytes isolated from septic wild-type or S100a9^(–/–)mice were co-cultured with naive CD4^(+)T cells,followed by proliferative assay.Pharmacological inhibition of S100A9 was implemented using Paquinimod via oral gavage.Results scRNA-seq analysis of human sepsis revealed substantial heterogeneity in monocyte compartments following the onset of sepsis,for which distinct monocyte subsets were enriched in disparate subclusters of septic patients.We identified a unique monocyte subset characterized by high expression of S100A family genes and low expression of human leukocyte antigen DR(HLA-DR),which were prominently enriched in septic patients and might exert immunosuppressive function.By combining single-cell transcriptomics of murine model of sepsis with in vivo experiments,we uncovered a similar subtype of monocyte significantly associated with late sepsis and immunocompromised status of septic mice,corresponding to HLA-DR^(low)S100A^(high)monocytes in human sepsis.Moreover,we found that S100A9^(+)monocytes exhibited profound immunosuppressive function on CD4^(+)T cell immune response and blockade of S100A9 using Paquinimod could partially reverse sepsis-induced immunosuppression.Conclusions This study identifies HLA-DR^(low)S100A^(high)monocytes correlated with immunosuppressive state upon septic challenge,inhibition of which can markedly mitigate sepsis-induced immune depression,thereby providing a novel therapeutic strategy for the management of sepsis.

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.

Effects of Shugan Jianpi Formula(疏肝健脾方)on Myeloid-Derived Suppression Cells-Mediated Depression Breast Cancer Mice

Objective： To observe the intervention effect of Shugan Jianpi Formula （疏肝健脾方,SGJPF） on a breast cancer mouse model with depression and investigate the underlying mechanism of SGJPF in preventing the development of breast cancer. Metkods： The breast cancer model was induced by inoculation of breast cancer cells, the depression model was induced by chronic stress stimuli, and the depression cancer model was established by combining the two factors. The mice were divided into 7 groups： normal control, depression model, tumor model, depression tumor model, SGJPF, chemotherapy, and SGJPF＋chemotherapy groups. The last 3 groups were depression breast cancer mice and treated respectively with SGJPF, chemotherapy drug gemcitabine （GEM）, and SGJPF alongside GEM. The condition of the mice was evaluated by the expression of 5-hydroxytryptamine in hippocampus after the sucrose water test and open field test, weight change, and survival time. Tumor growth was monitored with in vivo imaging. Flow cytometry was used to analyze the level of myeloid-derived suppression cell （MDSC） in the mouse spleen, T cell subsets, and the early apoptosis of CD8~ T cells, Results： The SGJPF＋GEM group had the highest inhibition rate and the longest survival time （P〈0.01）. The MDSC level and the apoptosis rate of CD8＊ T cells was the highest in the SGJPF＋GEM group （P〈0.05）. Conclusions： Depressive disorders and tumor growth could suppress the immune function of mice to different degrees, and the microenvironment in late 4T1 inflammatory breast cancer may play an important role in the pathological process. SGJYF could regulate the immune microenvironment by reducing CD8＊ T lymphocyte apoptosis and tumor cell activity, increasing immune surveillance capability, and inhibiting MDSC proliferation, thus prolonging the survival time of tumor-bearing mice.

Glucocorticoid receptor promotes the function of myeloid-derived suppressor cells by suppressing HIF1α-dependent glycolysis

Immunomodulatory signaling imposes tight regulations on metabolic programs within immune cells and consequentially determines immune response outcomes.Although the glucocorticoid receptor(GR)has been recently implicated in regulating the function of myeloid-derived suppressor cells(MDSCs),whether the dysregulation of GR in MDSCs is involved in immune-mediated hepatic diseases and how GR regulates the function of MDSCs in such a context remains unknown.Here,we revealed the dysregulation of GR expression in MDSCs during innate immunological hepatic injury(IMH)and found that GR regulates the function of MDSCs through modulating HIF1α-dependent glycolysis.Pharmacological modulation of GR by its agonist(dexamethasone,Dex)protects IMH mice against inflammatory injury.Mechanistically,GR signaling suppresses HIF1αand HIF1α-dependent glycolysis in MDSCs and thus promotes the immune suppressive activity of MDSCs.Our studies reveal a role of GR-HIF1αin regulating the metabolism and function of MDSCs and further implicate MDSC GR signaling as a potential therapeutic target in hepatic diseases that are driven by innate immune cell-mediated systemic inflammation.

The possible role and clinical implication of myeloid-derived suppressor cells in the peripheral blood of patients with hepatitis B virus-related acute-on-chronic liver failure

Objective To explore the possible role and clinical implications of myeloid-derived suppressor cells(MDSC)in the peripheral blood of patients with hepatitis B virus(HBV)-related acute-on-chronic liver failure(HBVACLF).Methods A total of 25 HBV-ACLF patients

Recent advances in myeloid-derived suppressor cell biology

In recent years,studying the role of myeloid-derived suppressor cells(MDSCs)in many pathological inflammatory conditions has become a very active research area.Although the role of MDSCs in cancer is relatively well established,their role in non-cancerous pathological conditions remains in its infancy resulting in much confusion.Our objectives in this review are to address some recent advances in MDSC research in order to minimize such confusion and to provide an insight into their function in the context of other diseases.The following topics will be specifically focused upon:(1)definition and characterization of MDSCs;(2)whether all MDSC populations consist of immature cells;(3)technical issues in MDSC isolation,estimation and characterization;(4)the origin of MDSCs and their anatomical distribution in health and disease;(5)mediators of MDSC expansion and accumulation;(6)factors that determine the expansion of one MDSC population over the other;(7)the Yin and Yang roles of MDSCs.Moreover,the functions of MDSCs will be addressed throughout the text.

胸腺法新对非小细胞肺癌患者髓源性抑制细胞的影响

目的通过胸腺法新与NSCLC患者外周血来源的髓源性抑制细胞共同培养,观察胸腺法新对髓源性抑制细胞亚群的影响,探索其可能的作用机制。方法收集2021年1月至2022年12月江西省胸科医院经病理组织学或细胞学检查确诊的30例NSCLC患者的外周静脉血和肿瘤组织以及30例健康志愿者的外周静脉血。以HLA-DR^(-)CD14^(-)CD33^(+)作为NSCLC患者的髓源性抑制细胞标志,运用流式细胞仪检测并分析NSCLC患者外周血单个核细胞(PBMNC)、肿瘤组织髓源性抑制细胞的表达及外周血单个核细胞与胸腺法新共培养前后髓源性抑制细胞比例的变化。结果NSCLC患者手术前外周血中髓源性抑制细胞表达为(1.62±0.46)%,明显高于健康志愿者的(0.41±0.14)%,差异有统计学意义(P<0.01);与健康组外周血中髓源性抑制细胞表达比较,NSCLC患者肿瘤组织中表达明显增高,两者分别是(0.41±0.14)%、(0.96±0.39)%,差异有统计学意义(P<0.01);NSCLC患者肿瘤组织中髓源性抑制细胞表达低于外周血中的表达,两者分别是(0.96±0.39)%、(1.62±0.46)%,差异有统计学意义(P<0.01)。胸腺法新与NSCLC患者外周血单个核细胞共培养前后,髓源性抑制细胞表达分别是(1.62±0.46)%、(0.53±0.11)%,差异有统计学意义(P<0.01)。结论髓源性抑制细胞参与NSCLC疾病进展过程,胸腺法新与NSCLC患者外周血共培养后髓源性抑制细胞表达下降,表示胸腺法新可能通过促进其分化成熟而调节患者的免疫功能。

中性粒细胞的免疫抑制亚群及功能和机制研究进展

中性粒细胞是健康成人外周血中数量最多的白细胞,是抗感染的第一道防线。具有免疫抑制性作用的中性粒细胞亚群包括如肿瘤相关中性粒细胞(TAN)、低密度中性粒细胞(LDN)。这些中性粒细胞亚群通过程序性死亡蛋白1及其配体1(PD-1/PD-L1)、抗原提呈、活性氧(ROS)、精氨酸酶1(Arg1)、诱导型一氧化氮合酶(iNOS)等途径,调节T细胞免疫功能、促进血管生成和肿瘤生长,参与多种生理和病理过程,产生了许多新兴的治疗靶点和预后指标。

Myeloid-specific expression of Stat3C results in conversion of bone marrow mesenchymal stem cells into alveolar type Ⅱ epithelial cells in the lung

Bone marrow mesenchymal stem cells (BMSCs) and myeloid lineage cells originate from the bone marrow, and influence each other in vivo. To elucidate the mechanism that controls the interrelationship between these two cell types, the signaling path- way of signal transducer and activator of transcription 3 (Stat3) was activated by overexpressing Stat3C in a newly established c-fms-rtTA/(TetO)7-CMV-Stat3C bitransgenic mouse model, In this system, Stat3C-Flag fusion protein was overexpressed in myeloid lineage cells after doxycycline treatment. Stat3C overexpression induced systematic elevation of macrophages and neutrophils in multiple organs. In the lung, tissue neoplastic pneumocyte proliferation was observed. After in vitro cultured hSP-B 1.5-kb lacZ BMSCs were injected into the bitransgenic mice, BMSCs were able to repopulate in multiple organs, self-renew in the bone marrow and spleen, and convert into alveolar type II epithelial cells. The bone marrow transplantation study indicated that increases of myeloid lineage cells and BMSC-AT II cell conversion were due to malfunction of myeloid progenitor cells as a result of Stat3C overexpression. The study supports the concept that activation of the Stat3 pathway in myeloid cells plays an important role in BMSC function, including homing, repopulating and converting into residential AT II epithelial cells in the lung.

CD14^+HLA-DR^(low/-)髓系来源抑制性细胞在Graves病中的检测及临床意义

目的:检测Graves病(Graves’disease,GD)患者外周血中髓系来源抑制性细胞(myeloid-derived suppressor cel l s,MDSCs)表达情况,探讨MDSCs在GD发生、发展中的作用。方法:收集52例初诊GD患者和30例健康志愿者外周血,以CD14+H L A-D Rl ow/-作为MDSCs的免疫标记,分别应用流式细胞术及ELISA方法检测外周血中MDSCs的比例及血浆细胞因子Arg-1,IL-6,G-CSF浓度;并分析MDSCs与GD患者甲状腺功能相关性。结果:GD患者外周血MDSCs比例明显升高,相比对照组差异有统计学意义(P<0.05),且GD患者病情平稳后,MDSCs水平较治疗前明显下降(P<0.05);MDSCs水平与GD患者甲状腺功能未见明显相关性;GD患者外周血浆A rg-1水平未见明显升高,IL-6及G-CSF浓度显著升高(P<0.05)。结论:GD患者外周血MDSCs升高,可能是GD发生和发展的重要因素。

Neutrophils in cancer—unresolved questions

There is growing recognition that neutrophils play an important role in cancer initiation, progression and metastasis. Although they are typically characterized as short-lived effector cells, neutrophils have been shown to acquire immunosuppressive and pro-tumorigenic functions that promote tumor progression and escape. As such, inhibition of their function or depletion of neutrophils are being explored as potential cancer therapies. However, growing evidence of neutrophil diversification in cancer and their potential anti-tumor roles raise many unresolved questions. Here, we review recent advances that address the definition,origin and function of neutrophils in cancer, and elaborate on obstacles that make the study of neutrophils challenging. We envision that this review will provide the groundwork for focused design of therapeutics that will specifically target "tumorreprogrammed" neutrophils while sparing normal neutrophils to improve patient outcomes.