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.

Analysis of the Peripheral Blood Helper T-Cell 17- Cell Level and Monocyte/Lymphocyte Ratio for Colorectal Cancer Prognosis Prediction

Objective: To investigate the value of peripheral blood helper T cell 17 cell level and monocyte/lymphocyte ratio to predict the prognosis of colorectal cancer patients. Methods: 74 colorectal cancer patients who attended Hospital 960 from January 2021 to January 2022 were retrospectively analyzed. Clinical data of the patients were collected, including gender, age, and histologic type. Immunohistochemical indexes such as Th17 cell level and monocyte/ lymphocyte ratio in the peripheral blood of patients were also collected. The prognosis of patients after treatment, as well as peripheral blood Th17 and MLR levels, were observed and analyzed. Results: After follow-up after treatment, in the final 74 patients, the prognosis was good in 32 patients, accounting for 43.24%, and the prognosis was bad in 42 patients, accounting for 56.76%. There were no significant differences between the average age and tumor diameters of the good prognosis and poor prognosis groups (P > 0.05). However, the TNM staging, intervention taken, differentiation degree, presence of distant metastasis, presence of lymph node metastasis, Th17 level, and MLR level are significantly different between the two groups (P < 0.05). Conclusion: Peripheral blood Th17 and MLR have predictive value for the prognosis of colorectal cancer patients, and high levels of peripheral blood Th17 and MLR imply poor prognosis. The detection of peripheral blood Th17 and MLR levels is simple and convenient and can be used as indicators to provide a reference for the prognostic assessment of colorectal cancer patients.

Effects of living and metabolically inactive mesenchymal stromal cells and their derivatives on monocytes and macrophages

Mesenchymal stromal cells (MSCs) are multipotent and self-renewing stem cellsthat have great potential as cell therapy for autoimmune and inflammatorydisorders, as well as for other clinical conditions, due to their immunoregulatoryand regenerative properties. MSCs modulate the inflammatory milieu by releasingsoluble factors and acting through cell-to-cell mechanisms. MSCs switch theclassical inflammatory status of monocytes and macrophages towards a nonclassicaland anti-inflammatory phenotype. This is characterized by an increasedsecretion of anti-inflammatory cytokines, a decreased release of pro-inflammatorycytokines, and changes in the expression of cell membrane molecules and inmetabolic pathways. The MSC modulation of monocyte and macrophage phenotypesseems to be critical for therapy effectiveness in several disease models, sincewhen these cells are depleted, no immunoregulatory effects are observed. Here,we review the effects of living MSCs (metabolically active cells) and metabolicallyinactive MSCs (dead cells that lost metabolic activity by induced inactivation) andtheir derivatives (extracellular vesicles, soluble factors, extracts, and microparticles)on the profile of macrophages and monocytes and the implications forimmunoregulatory and reparative processes. This review includes mechanisms ofaction exhibited in these different therapeutic appro-aches, which induce the antiinflammatoryproperties of monocytes and macrophages. Finally, we overviewseveral possibilities of therapeutic applications of these cells and their derivatives,with results regarding monocytes and macrophages in animal model studies andsome clinical trials.

Phenotypic and functional characteristics of dendritic cells derived from human peripheral blood monocytes

Objective: This study is aimed at developing a simple and easy way to generate dendritic cells (DCs) from human peripheral blood monocytes (PBMCs) in vitro. Methods: PBMCs were isolated directly from white blood cell rather than whole blood and purified by patching methods (collecting the attached cell and removing the suspension cell). DCs were then generated by culturing PBMCs for six days with 30 ng/ml recombinant human granulocyte-macrophage stimulating factor (rhGM-CSF) and 20 ng/ml recombinant human interleukin-4 (rhIL-4) in vitro. On the sixth day, TNF-alpha (TNFα) 30 ng/ml was added into some DC cultures, which were then incubated for two additional days. The morphology was monitored by light microscopy and transmission electronic microscopy, and the phenotypes were determined by flow cytometry. Autologous mixed leukocyte reac-tions (MLR) were used to characterize DC function after TNFα or lipopolysaccharide (LPS) stimulations for 24 h. Results: After six days of culture, the monocytes developed significant dendritic morphology and a portion of cells expressed CD1a, CD80 and CD86, features of DCs. TNFα treatment induced DCs maturation and up-regulation of CD80, CD86 and CD83. Autologous MLR demonstrated that these DCs possess potent T-cell stimulatory capacity. Conclusion: This study developed a simple and easy way to generate DCs from PBMCs exposed to rhGM-CSF and rhIL-4. The DCs produced by this method acquired morphologic and antigenic characteristics of DCs.

B7-H4 expression is elevated in human U251 glioma stem-like cells and is inducible in monocytes cultured with U251 stem-like cell conditioned medium

Previous studies indicated that B7-H4,the youngest B7 family,negatively regulates T cell-mediated immunity and is significantly overexpressed in many human tumors.Tumor stem cells are purported to play a role in tumor renewal and resistance to radiation and chemotherapy.However,the link between B7-H4and tumor stem cells is unclear.In this study,we investigated B7-H4 expression in the medium of human glioma U251 cell cultures.Immunofluorescence results showed that U251 cells cultured in serum-free medium(supplemented with 2%B27,20 ng/mL epidermal growth factor,20 ng/mL basic fibroblast growth factor)maintained stem-like cell characteristics,including expression of stem cell marker CD133 and the neural progenitor cell markers nestin and SOX2.In contrast,U251 cells cultured in serum-containing medium highly expressed differentiation marker glial fibrillary acidic protein.Flow cytometry analysis showed serum-free medium-cultured U251 cells expressed higher intracellular B7-H4 than serumcontaining medium-cultured U251 cells(24%-35%vs.8%-11%,P<0.001).Immunofluorescence in purified monocytes from normal human peripheral blood mononuclear cells revealed moderate expression of B7-H4 after stimulation with conditioned medium from U251 cells cultured in serum-containing medium.Moreover,conditioned medium from U251 stem-like cells had a significant stimulation effect on B7-H4expression compared with serum-containing conditioned medium(P<0.01).Negative costimulatory molecule B7-H4 was preferentially expressed in U251 stem-like cells,and conditioned medium from these cells more effectively induced monocytes to express B7-H4 than conditioned medium from U251 cells cultured in the presence of serum.Our results show that U251 stem-like cells may play a more crucial role in tumor immunoloregulation with high expression of B7-H4.

Distinct toll-like receptor expression in monocytes and T cells in chronic HCV infection

瞄准：丙肝病毒经常建立长期的感染。最近的研究建议病毒、细菌的感染在与控制相比的感染 HCV 的病人是更普通的。病原体被像使用费的受体(TLR ) 认出塑造适应、天生的有免疫力的回答。方法：在这研究，估计感染 HCV 的主人的能力认识到入侵病原体，我们调查了像使用费的受体表示在天生(单核白血球) 并且适应(T 房间) 由即时 PCR 的有免疫力的房间。结果：我们决定 RNA 为 TLR 铺平 2， 6。7， 8， 9 和 10 个 mRNA 层次起来与控制相比在感染 HCV 的病人在单核白血球和 T 房间调整了。TLR4 在 T 淋巴细胞在仅仅上面被调整，当 TLR5 有选择地在感染 HCV 的病人的单核白血球被增加时。MD-2， TLR4 合作受体，当 CD14 和 MyD88 仅仅在单核白血球被增加时，在病人的单核白血球和 T 房间被增加。结论：我们的数据在多半在感染 HCV 的个人联系到病原体和有免疫力的防卫的天生的识别的 TLR 表示上披露新奇详情。

Modulation of the immune response by heterogeneous monocytes and dendritic cells in lung cancer

Different subpopulations of monocytes and dendritic cells(DCs)may have a key impact on the modulation of the immune response in malignancy.In this review,we summarize the monocyte and DCs heterogeneity and their function in the context of modulating the immune response in cancer.Subgroups of monocytes may play opposing roles in cancer,depending on the tumour growth and progression as well as the type of cancer.Monocytes can have pro-tumour and anti-tumour functions and can also differentiate into monocyte-derived DCs(moDCs).MoDCs have a similar antigen presentation ability as classical DCs,including cross-priming,a process by which DCs activate CD8 T-cells by crosspresenting exogenous antigens.DCs play a critical role in generating anti-tumour CD8 T-cell immunity.DCs have plastic characteristics and show distinct phenotypes depending on their mature state and depending on the influence of the tumour microenvironment.MoDCs and other DC subsets have been attracting increased interest owing to their possible beneficial effects in cancer immunotherapy.This review also highlights key strategies deploying specific DC subpopulations in combination with other therapies to enhance the anti-tumour response and summarizes the latest ongoing and completed clinical trials using DCs in lung cancer.

Expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin on dendritic cells generated from human peripheral blood monocytes

瞄准：从人的外部血产生树枝状的房间(DC ) 并且检测树枝状的房间特定的细胞间的粘附分子 3 的表示抓住 nonintegrin (DC 签名；CD209 ) 为在丙肝的 DC 签名的进一步的学习病毒(HCV ) 传播。方法：外部血单核白血球被 Ficoll-Hypaque 沉积从健康个人的血孤立并且在完全的中等包含 rhGM-CSF 和 rhIL-4 有教养。房间每二天是有教养的七天了，与 cytokine 增加获得不成熟的 DC。有教养的房间的特征在轻、扫描的显微镜下面被观察，并且 DC 签名的表示被免疫荧光染色检测。结果：在七天的文化以后，有 DC 的典型特征的很多房间出现了。他们的特征在轻、扫描的电子显微镜下面被观察。这些房间有 bipolar 的象那些那样的许多房间形状伸长房间，精致的星形细胞和 DC。DC 签名被免疫荧光在栽培树枝状的房间上染色和它的表示水平检测高。结论：有 DC 签名的高表情的 DC 能在完全的中等包含 rhGM-CSF 和 rhIL-4 从人的外部血单核白血球被产生。

IN VITRO ANTI-HEPATOMA EFFECTS OF MONOCYTES AND KUPFFER CELLS ISOLATED FROM HEPATOMA PATIENTS AFTER TREATMENT WITH BIOLOGICAL IMMUNE STIMULANTS

Monocytes (MC), lymphocytes (LC) and Kupffer cells (KC) were isolated respectively from blood and surgical liver samples of patients suffering from he-patocellular carcinoma (HCC). 13 patients were given BCG, mixed bacterium vaccine (MBV) and human white blood cell interferon (IFN), the other 3 patients were not treated with any biological immune stimulants (BIS) and served as controls. The cytosta-tic and cytotoxic effects of MC and KC on human hepatoma SMMC-7721 (TC) were assayed in vitro and the numbers of T total (Tt), T helper (Th) and T suppressor (Ts) cells were counted using CD monoclonal antibody immunofluorescence. The results were as follows: (1) On the 7th day after the first administration of BIS, the cytostatic and cytotoxic effects of MC on TC showed obvious increase over pre-administration. The activity of BIS was 1 ?5 times as high as that in the controls. (2) After 3 administrations, the cytostatic effect of MC on TC increased to the normal level (84%), while the controls remained as before (45%). (3) On the 7th day after first administration, cytostatic and cytotoxic effects of KC on TC were 0.5 and 1 times higher respectively than those of the controls. (4) The numbers of Tt and Th of patients given BIS increased continuously; on the contrary Ts decreased in number. These results indicate that combined use of BCG, MBV and IFN can actively enhance the immune anti-hepatoma function of patients suffering from HCC.

Malarial pigment enhances heat shock protein-27 in THP-1 cells:new perspectives for in vitro studies on monocyte apoptosis prevention

Objective:To investigate the effect of malarial pigment(hemozoin,HZ) on expression of heat shock proteins(HSPs) and cell viability in human monocytes by using a stable cell line(THP-1 cells).Methods:THP-1 cells were fed with native HZ or treated with pro-apoptotic molecule gliotoxin for 9 h.Thereafter,the protein expression of HSP-27 and HSP-70 was evaluated by western blotting.Alternatively,HZ-fed cells were cultured up to 72 h and cell viability parameters(survival,apoptosis and necrosis rates) were measured by flow cytometric analysis. Results:HZ increased basal protein levels of HSP-27 without altering those of HSP-70 in THP-1 cells,and promoted long-term cell survival without inducing apoptosis.As expected,gliotoxin inhibited HSP-27 protein expression and promoted long-term cell apoptosis.Conclusions: Present data show that HZ prevents cell apoptosis and enhances the expression of anli-apoptotic HSP-27 in THP-1 cells,confirming the previous evidences obtained from HZ-fed immunopurified monocytes.Since the use of a stable cell line is pivotal to perform HSP-27 silencing experiments, monocytic THP-1 cells could be a good candidate line for such an approach,which is heavily required to clarify the role of HSP-27 in survival of impaired HZ-fed monocytes during falciparum malaria.

Adult endothelial progenitor cells from human peripheral blood maintain monocyte/macrophage function throughout in vitro culture

密度坡度 centrifugation 从外部血孤立的 Mononuclear 房间(MNC ) 是人的 fibronectin 涂的文化盘子上的 plated 并且在 EGM-2 有教养中等。依附塑造锭子的房间，由一些调查者作为 endothelial 祖先房间(EPC ) 报导了，从支持者回合房间伸长了，但是没从以前想了的房间的一个小数字增殖。主要 EPC 的生长曲线证明房间几乎没有很少 proliferative 能力。当他们能也表示 CD14 时，流动 cytometry 分析证明房间能表示一些 endothelial 系标记，它在整个文化被认为单核白血球 / 巨噬细胞系的一个标记。在 endothelial 函数试金，房间比在反向的抄写聚合酶的成熟 endothelial 房间锁住反应并且没显示一个能力在 vitro 在 angiogenesis 试金开发像试管的结构表明了 eNOS 的表示的底层。在这研究，我们由低密度的脂蛋白(Dil-Ac-LDL ) 和印度墨水举起测试的联合标记 Dil 的乙酰 ated 识别了 EPC 的单音的似细胞的功能。所有房间是双的为在天的 Dil-Ac-LDL 和印度墨水举起积极 4 文化， 14 和 28，它意味着 EPC 在整个文化维持了单音的似细胞的功能。因此，尽管从外部 MNC 的成年 EPC 有一些 endothelial 系性质，他们维持典型 monocytic 功能并且几乎没有很少 proliferative 能力。

Proteomic profile of human monocytic cells infected with dengue virus

Objective: To identify the changes in the proteome of U937 cells infected with dengue virus(DENV).Methods: In this study, differentiated U937 cultures were infected with two DENV-2strains, one of which was associated with dengue(DENV-2/NG) and the other one with severe dengue(DENV-2/16681), with the aim of determining the cellular proteomic profiles under different infection conditions. Cellular proteins were extracted and separated by two-dimensional electrophoresis, and those proteins with differential expression profiles were identified by mass spectrometry. The obtained results were correlated with cellular viability, the number of infectious viral particles, and the viral DNA/protein quantity.Results: In comparison with non-infected cultures, in the cells infected with the DENV-2/NG strain, nine proteins were expressed differentially(five were upregulated and four were downregulated); in those cultures infected with the DENV-2/16681 strain, six proteins were differentially expressed(two were downregulated and four were upregulated). The downregulated proteins included fatty acid-binding protein, heterogeneous nuclear ribonucleoprotein 1, protein disulfide isomerase, enolase 1, heat shock 70 k Da protein 9, phosphotyrosyl phosphatase, and annexin IV. The upregulated proteins included heat shock 90 k Da protein AA1, tubulin beta, enolase 1, pyruvate kinase,transaldolase and phospholipase C-alpha.Conclusions: Because the monocyte/macrophage lineage is critical for disease pathogenicity, additional studies on these proteins could provide a better understanding of the cellular response to DENV infection and could help identify new therapeutic targets against infection.

Oxidatively Modified Very Low Density Lipoprotein Enhances Monocyte Adhesion to Endothelial Cells

Very low density lipoprotein (VLDL) was incubated with CuCl2(10 μmol/L) at room temperature for 24 hours.The thiobarbituric acid reactive substance (TBARS) was much higher and the electrophoretic mobility was much faster in VLDL after incubation with CuCl2 than that in VLDL without incubation with CuCl2.It demonstrated that VLDL was oxidatively modified by Cu2+. Endothelial cells were pretreated with normal VLDL ( N-VLDL ) and oxidatively modified VLDL (OVLDL) and then the adhesion of monocyte to endothelial cells was assayed. We observed that O-VLDL at all the concentrations used enhanced monocyte adhesion to endothelial cells significantly. The results suggest that oxidative modification of VLDL may play a role in the early stage of atherogenesis by increasing monocyte adhesion to endothelial cells.

Effect of serum concentration on adhesion of monocytic THP-1 cells onto cultured EC monolayer and EC-SMC co-culture

Background:The adhesion of monocytes to the endothelium following accumulation of low-density lipoprotein (LDL) in subendothelial spaces is an important step in the development of intimal hyperplasia in arterially implanted vein grafts and atherosclerosis in both animals and humans. However, it is not well known how serum factors affect the adhesion of monocytes. Methods: We have studied the effect of fetal calf serum (FCS), which we considered a source of LDL, on the adhesion of monocytes to endothelial cells (ECs) by using human monocytic THP-1 cells and both a monolayer of cultured bovine aortic endothelial cells (EC monoculture) and a co-culture with bovine aortic smooth muscle cells (EC-SMC co-culture). Results: It was found that the addition of FCS to the medium greatly affected the adhesion of THP-1 cells, and the higher the concentration of FCS in the medium, the greater the adhesion of THP-1 cells to endothelial cells. Adhesion of THP-1 cells to an EC-SMC co-culture was approximately twofold greater than that to an EC monoculture, and after adhering to endothelial cells, many THP-1 cells trans-migrated into the layer of smooth muscle cells. Conclusion: The results suggest that the elevation of the LDL (cholesterol) level in blood provides a favorable condition for the development of intimal hyperplasia and atherosclerosis by promoting the adhesion of monocytes to the endothelium and their subsequent migration into subendothelial spaces.

The role of monocyte-lineage cells in human immunodeficiency virus persistence: mechanisms and progress

Human immunodeficiency virus type 1(HIV-1) persistence is a major barrier to the successful treatment and eradication of acquired immunodeficiency syndrome(AIDS).In addition to resting CD4+ T cells,a significant long-lived compartment of HIV-1 infection in vivo includes blood monocytes and tissue macrophages.Studying HIV-1 persistence in monocyte-lineage cells is critical because these cells are important HIV-1 target cells in vivo.Monocyte-lineage cells,including monocytes,dendritic cells(DCs) and macrophages,play a significant role in HIV-1 infection and transmission.These cells have been implicated as viral reservoirs that facilitate HIV-1 latency and persistence.A better understanding of HIV-1 interactions with monocyte-lineage cells can potentially aid in the development of new approaches for intervention.This minireview highlights the latest advances in understanding the role of monocyte-lineage cells in HIV-1 persistence and emphasizes new insights into the mechanisms underlying viral persistence.

Essential role of monocytes and macrophages in the progression of acute pancreatitis

Acute pancreatitis(AP) is an inflammatory condition of the pancreas caused by an imbalance in factors involved in maintaining cellular homeostasis.Earliest events in AP occur within acinar cells accompanied by other principal contributors to the inflammatory response i.e.the endothelial cells,immunocytes(granulocytes,monocytes/macrophages,lymphocytes) and neutrophils.Monocytes/macrophages are important inflammatory mediators,involved in the pathophysiology of AP,known to reside in the peritoneal cavity(in the vicinity of the pancreas) and in peripancreatic tissue.Recent studies suggested that impaired clearance of injured acini by macrophages is associated with an altered cytokine reaction which may constitute a basis for progression of AP.This review focuses on the role of monocytes/macrophages in progression of AP and discusses f indings on the inflammatory process involved.

Role of the CXCR4-SDF1-HMGB1 pathway in the directional migration of cells and regeneration of affected organs

In recent years,several studies have reported positive outcomes of cell-based therapies despite insufficient engraftment of transplanted cells.These findings have created a huge interest in the regenerative potential of paracrine factors released from transplanted stem or progenitor cells.Interestingly,this notion has also led scientists to question the role of proteins in the secretome produced by cells,tissues or organisms under certain conditions or at a particular time of regenerative therapy.Further studies have revealed that the secretomes derived from different cell types contain paracrine factors that could help to prevent apoptosis and induce proliferation of cells residing within the tissues of affected organs.This could also facilitate the migration of immune,progenitor and stem cells within the body to the site of inflammation.Of these different paracrine factors present within the secretome,researchers have given proper consideration to stromal cell-derived factor-1(SDF1)that plays a vital role in tissue-specific migration of the cells needed for regeneration.Recently researchers recognized that SDF1 could facilitate site-specific migration of cells by regulating SDF1-CXCR4 and/or HMGB1-SDF1-CXCR4 pathways which is vital for tissue regeneration.Hence in this study,we have attempted to describe the role of different types of cells within the body in facilitating regeneration while emphasizing the HMGB1-SDF1-CXCR4 pathway that orchestrates the migration of cells to the site where regeneration is needed.

Day 100 Absolute Monocyte/Lymphocyte Prognostic Score and Survival Post Autologous Peripheral Blood Hematopoietic Stem Cell Transplantation in Diffuse Large B-Cell Lymphoma

Day 100 prognostic factors post-autologous peripheral blood hematopoietic stem cell transplantation (APBHSCT) to predict clinical outcomes in diffuse large B-cell lymphoma (DLBCL) patients have not been studied. Thus, we retrospectively examined if day 100 absolute monocyte/lymphocyte prognostic score (AMLPS-100) affects clinical outcomes by landmark analysis from day 100 post-APBHSCT in DLBCL. Only DLBCL patients in complete remission at day 100 post-APBHSCT were evaluated. From 2000 to 2007, 134 consecutive DLBCL patients are qualified for the study. Patients with a day 100 absolute monocyte count (AMC-100) ≥ 630 cells/μL and day 100 absolute lymphocyte count (ALC-100) ≤ 1000 cells/μL experienced inferior overall survival (OS) and progression free survival (PFS). On multivariate analysis, the AMC-100 and ALC-100 remained independent predictors of OS and PFS. Combining both values into the AMLPS-100, the 5-year OS rates for low, intermediate, and high AMLPS-100 risk groups were 94% (95% CI, 83.0% - 98.1%), 70% (95% CI, 58.6% - 80.1%), and 13% (95% CI, 3.4% - 40.5%), respectively;and the 5-year PFS rates were 87% (95% CI, 74.0% - 94.1%), 68% (95% CI, 56.0% - 77.8%), and 13% (95% CI, 3.4% - 40.5%), respectively. The AMLPS-100 is a simple biomarker score that can stratify clinical outcomes from day 100 post-APBHSCT in DLBCL patients.