Infiltration by monocytes of the central nervous system and its role in multiple sclerosis: reflections on therapeutic strategies

Mononuclear macrophage infiltration in the central nervous system is a prominent feature of neuroinflammation. Recent studies on the pathogenesis and progression of multiple sclerosis have highlighted the multiple roles of mononuclear macrophages in the neuroinflammatory process. Monocytes play a significant role in neuroinflammation, and managing neuroinflammation by manipulating peripheral monocytes stands out as an effective strategy for the treatment of multiple sclerosis, leading to improved patient outcomes. This review outlines the steps involved in the entry of myeloid monocytes into the central nervous system that are targets for effective intervention: the activation of bone marrow hematopoiesis, migration of monocytes in the blood, and penetration of the blood–brain barrier by monocytes. Finally, we summarize the different monocyte subpopulations and their effects on the central nervous system based on phenotypic differences. As activated microglia resemble monocyte-derived macrophages, it is important to accurately identify the role of monocyte-derived macrophages in disease. Depending on the roles played by monocyte-derived macrophages at different stages of the disease, several of these processes can be interrupted to limit neuroinflammation and improve patient prognosis. Here, we discuss possible strategies to target monocytes in neurological diseases, focusing on three key aspects of monocyte infiltration into the central nervous system, to provide new ideas for the treatment of neurodegenerative diseases.

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.

Arsenic trioxide inhibites transgenic tumor necrosis factor-α promoter activity in vascular smooth muscle cells and THP-1 monocytes in vitro

Aim This study was to evaluate the effect of arsenic trioxide （As2O3） on the transgenic TNF-α promoter activity in cultured vascular smooth muscle cells （VSMCs） and THP-1 monocytes. Methods Human TNF-α promoter was constructed by reporter gene system and was transiently transfected into VSMCs and THP-1 in vitro. The promoter activity was tested by luciferase activity with or without LPS and Ang Ⅱ stimulation, before and after different dosage of As2O3 treatment. Results 1. TNF-α promoter effectively expressed in VSMCs and THP-1 compared with CMV promoter （58.3% and 80.9%, respectively）. Both LPS and Ang Ⅱ significantly up-regulated TNF-α promoter activity （P〈0.05）. 2. As2O3 significantly inhibited, both intact and LPS/Ang Ⅱ stimulated promoter activity, in a dose dependent manner （P〈0.05）, and in both cell type. Conclusion These results manifested that, the inhibition effect of As2O3 on the activity of human TNF-α promoter indicated its potential inhibition on pro-inflammatory cytokine genes expression at transcriptional level and its potential anti-inflammatory property in the cardiovascular system.

Effect of HSV-2 Infected Monocytes on the Production of TNF-a and IL-6

Objective: In order to detect the role of monocytes inHSV-2 infection, we studied the effect of herpes sim-plex Virus-2 infection on the production of tumor ne-crosis factor (TNF-σ), interleukin-6 (IL-6) secretedby monocytes. Methods: Monocytes were infected by HSV-2 (333Strain). Culture supernatants were collected at 1, 3,5, 7 days post-infection. The levels of TNF-α, IL-6were measured by enzyme-linked immunosorbent as-say (ELISA). Results: The levels of TNF-α secretion by mono-cytes significantly decreased on first day post-infection. The levels of IL-6 significantly decreasedon first and third days post-infection, and then gradu-ally increased to the control on seventh day post-infection. Conclusions: TNF-α and IL-6 production by mono-cytes was inhibited during HSV-2 infection. The pro-duction of cytokines may play an important role inherpes simplex viurs-2 pathogenicity and immunity.

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.

Monocytes in systematic inflammatory response syndrome:Differences between sepsis and acute pancreatitis

AIM: To unravel the differences between systematic in- flammatory response syndrome (SIRS) of acute pancre- atitis compared to the same syndrome in sepsis. METHODS: Twenty-five patients were enrolled, 12 with sepsis and 13 acute pancreatitis. After diagnosis 20 ml blood was sampled. Half were assayed for isolation of monocytes and 10 ml was centrifuged for serum test of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6). Half of monocytes were incubated in the presence of patients’ serum and supernatants were collected. The other half was treated for estimation of optical photom- etry under caspase-3 inhibition. TNFα and IL-6 were es- timated by an enzyme immunoassay. RESULTS: median ± SE of serum IL-6 in septic patients and acute pancreatitis patients was 192.30 ± 35.40 ng/L and 21.00 ± 16.05 ng/L, respectively (P < 0.01). Re- spective values of caspase-3 were 0.94 ± 0.17 pmol/min 104 cells and 0.34 ± 0.09 pmol/min 104 cells (P < 0.05). IL-6 of monocyte supernatants of patients with sepsis was significantly increased after addition of patients’ serum, while that of patients with acute pancreatitis did not show significant difference. CONCLUSION: The data have shown that monocyte activity is different between acute pancreatitis and sepsis. This phenomenon might be explained as a different pathway to the pro-inflammatory cytokines release or could be a novel anti-inflammatory response in acute pancreatitis.

HCV-specific cytokine induction in monocytes of patients with different outcomes of hepatitis C

AIM:Cytokine release by macrophages critically determines the type of immune response to an antigen.Therefore,we studied hepatitis C virus(HCV)-specific induction of interleukins-1β,-10,-12(IL-1β,IL-10,IL-12),and tumor necrosis factor-α(TNF-α)in monocytes. METHODS:Intracallular cytokine expression was studied by flow cytometry in 23 patients with chronic hepatitis C,14 anti-HCV seropositives without viremia and 11 controls after stimulation of peripheral blood mononuclear calls with recombinant core,NS3,NS4,NSSa and NSSb proteins. RESULTS:Patients with HCV viremia revealed greater spontaneous expression of IL-1β,TNF-α,and IL-10. Furthermore,greater than twofold higher IL-10 expression was induced by the HCV antigens in chronic hepatitis C than in the other two groups(P<0.05).In contrast,neither IL- 12 nor TNF-α was induced preferentially. CONCLUSION:In chronic hepatitis C antigen-specific cytokine induction in monocytes is apparently shifted towards predominant IL-10 induction-not counterbalanced by antiviral type 1 cytokines.This may contribute to persistent viral replication.

Specific function and modulation of teleost monocytes/macrophages: polarization and phagocytosis

Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals.Due to whole genome duplication and en vironme ntal adaptati on,teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals.A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals.In this review,we summarize the differences in polarizati on and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.

Onset of Coronary Heart Disease is Associated with HCMV Infection and Increased CD14^+CD16^+Monocytes in a Population of Weifang,China

Objective To investigate the relationship between human cytomegalovirus(HCMV)infection and peripheral blood CD14+CD16+monocytes in the pathogenesis of coronary heart disease(CHD),and to elucidate the mechanism of pathogenesis in CHD by analyzing the correlation between infection,inflammation,and CHD,to provide a basis for the prevention,evaluation,and treatment of the disease.Methods In total,192 patients with CHD were divided into three groups:latent CHD,angina pectoris,and myocardial infarction.HCMV-IgM and-IgG antibodies were assessed using ELISA;CD14+CD16+monocytes were counted using a five-type automated hematology analyzer;mononuclear cells were assessed using fluorescence-activated cell sorting;and an automatic biochemical analyzer was used to measure the levels of triglyceride,cholesterol,high-and low-density lipoprotein cholesterols,lipoprotein,hs-CRp and Hcy.Results The positive rates of HCMV-IgM and-IgG were significantly higher in the CHD groups than in the control group.HCMV infection affects lipid metabolism to promote immune and inflammatory responses.Conclusion HCMV infection has a specific correlation with the occurrence and development of CHD.The expression of CD14+CD16+mononuclear cells in the CHD group was increased accordingly and correlated with acute HCMV infection.Thus,HCMV antibody as well as peripheral blood CD14+CD16+mononuclear cells can be used to monitor the occurrence and development of CHD.

Effect of Menopause on Gene Expression Profiles of Circu-lating Monocytes: A Pilot in vivo Microarray Study

Menopause is one of the key physiological events in the female life and can increase the risk for a number of complex autoimmune, neurodegenerative, metabolic, and cardiovascular disorders. Circulating monocytes can differentiate into various cell types and play an important role in tissue morphogenesis and immune response. We studied gene expression profiles of peripheral blood monocytes in healthy pre- and postmenopausal women using Affymetrix Human U133A GeneChip array that contains probes for -14,500 genes. Comparative analyses between the samples showed that 20 genes were up- and 20 were down-regulated. Of these genes, 28 were classified into six major GO categories relevant to such biological processes as the cell proliferation, immune response, cellular metabolism, and the others. The remaining 12 genes have yet unidentified biological functions. Our results support the hypothesis that functional state of circulating monocytes is indeed affected by menopause, and resulting changes may be determined through the genomewide gene expression profiling. Several differentially expressed genes identified in this study may be candidates for further studies of menopause-associated systemic autoimmune, neurodegenerative, and cardiovascular disorders. Our study is only the first attempt in this direction, but it lays a basis for further research.

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

AIM： Hepatitis C virus often establishes chronic infections. Recent studies suggest that viral and bacterial infections are more common in HCV-infected patients compared to controls. Pathogens are recognized by Toll-like receptors （TLRs） to shape adaptive and innate immune responses. METHODS： In this study, to infected host to recognize assess the ability of HCV-infected host to recognize invading pathogens, we investigated Toll-like receptor expression in innate （monocytes） and adaptive （T cells） immune cells by realtime PCR. RESULTS： We determined that RNA levels for TLRs 2, 6. 7, 8, 9 and 10 mRNA levels were upregulated in both monocytes and T cells in HCV-infected patients compared to controls. TLR4 was only upregulated in T lymphocytes, while TLR5 was selectively increased in monocytes of HCV-infected patients. MD-2, a TLR4 coreceptor, was increased in patients＇ monocytes and T cells while CD14 and MyD88 were increased only in monocytes. CONCLUSION： Our data reveal novel details on TLR expression that likely relates to innate recognition of pathogens and immune defense in HCV-infected individuals.

Systemic immune inflammation index, ratio of lymphocytes to monocytes, lactate dehydrogenase and prognosis of diffuse large Bcell lymphoma patients

BACKGROUND In malignant tumors,inflammation plays a vital role in the development,invasion,and metastasis of cancer cells.Diffuse large B-cell lymphoma(DLBCL),the most common malignant proliferative disease of the lymphatic system,is commonly associated with inflammation.The international prognostic index(IPI),which includes age,lactate dehydrogenase(LDH),number of extranodal lesions,Ann Arbor score,and Eastern Cooperative Oncology Group(ECOG)score,can evaluate the prognosis of DLBCL.However,its use in accurately identifying highrisk patients and guiding treatment is poor.Therefore,it is important to find novel immune markers in predicting the prognosis of DLBCL patients.AIM To determine the association between the systemic immune inflammation index(SII),ratio of lymphocytes to monocytes(LMR),ratio of LMR to LDH(LMR/LDH),and prognosis of patients with DLBCL.METHODS A total of 68 patients diagnosed with DLBCL,treated in our hospital between January 2016 and January 2020,were included.χ2 test,Pearson’s R correlation,Kaplan Meier curves,and Cox proportional risk regression analysis were used.The differences in the SII,LMR,and LMR/LDH among patients with different clinicopathological features were analyzed.The differences in progression-free survival time among patients with different SII,LMR,and LMR/LDH expressions and influencing factors affecting the prognosis of DLBCL patients,were also analyzed.RESULTS The LMR and LMR/LDH in patients with Ann Arbor stage III–IV,ECOG score≥2,and SII,IPI score 2–5 were significantly higher than those of patients with Ann Arbor stage I-II and ECOG score<2(P<0.05).Patients with high SII,LMR,and LMR/LDH had progression-free survival times of 34 mo(95%CI:32.52–38.50),35 mo(95%CI:33.42–36.58)and 35 mo(95%CI:33.49–36.51),respectively,which were significantly lower than those with low SII,LMR,and LMR/LDH(P<0.05);the SII,LMR,and LMR/LDH were positively correlated(P<0.05).Cox proportional risk regression analysis showed that the SII,LMR,and LMR/LDH were influencing factors for the prognosis of DLBCL patients(hazard ratio=1.143,1.665,and 1.704,respectively;P<0.05).CONCLUSION The SII,LMR,and LMR/LDH are related to the clinicopathological features of DLCBL,and they also influence the prognosis of patients with the disease.

ATG16L1 and NOD2 polymorphisms enhance phagocytosis in monocytes of Crohn's disease patients

AIM: To investigate if the presence of relevant genetic polymorphisms has effect on the effectual clearance of bacteria by monocytes and granulocytes in patients with Crohn&#x02019;s disease (CD).

Role of macrophages and monocytes in hepatitis C virus infections

A number of studies conducted over many years have shown that hepatitis C virus(HCV)can infect a variety of cell types.In vivo infection of monocytes,macrophages,and dendritic cells by HCV has been frequently shown by a number of researchers.These studies have demonstrated replication of HCV by detecting the presence of both negative genomic strands and a variety of non-structural HCV proteins in infected cells.In addition,analyses of genome sequences have also shown that different cell types can harbor different HCV variants.Investigators have also done preliminary studies of which cellular genes are affected by HCV infection,but there have not yet been a sufficient number of these studies to understand the effects of infection on these cells.Analyses of in vitro HCV replication have shown that monocytes,macrophages and dendritic cells can be infected by HCV from patient sera or plasma.These studies suggest that entry and cellular locations may vary between different cell types.Some studies suggest that macrophages may preferentially allow HCV genotype 1 to replicate,but macrophages do not appear to select particular hypervariable regions.Overall,these studies agree with a model where monocytes and macrophages act as an amplification system,in which these cells are infected and show few cytopathic effects,but continuously produce HCV.This allows them to produce virus over an extended time and allows its spread to other cell types.

Effect of bone marrow-derived monocytes transfected with RNA of mouse colon carcinoma on specific antitumor immunity

AIM: To investigate the effect of bone marrow-derived monocytes transfected with RNA of CT-26 (a cell line of mouse colon carcinoma) on antitumor immunity. METHODS: Mouse bone marrow-derived monocytes were incubated with mouse granulocyte macrophage colony stimulating factor (mGM-CSF) in vitro, and the purity of monocytes was detected by flow cytometry. Total RNA of CT-26 was obtained by TRIzol's process, and monocytes were transfected by TransMessenger in vitro. The activity of cytotoxic T lymphocytes (CTL) in vivo was estimated by the modified lactate dehydrogenase (LDH) release assay. Changes of tumor size in mice and animal's survival time were observed in different groups. RESULTS: Monocytes from mouse bone marrow were successfully incubated, and the positive rate of CDllb was over 95%. Vaccination of the monocytes transfected with total RNA induced a high level of specific CTL activity in vivo, and made mice resistant to the subsequent challenge of parental tumor cells. In vivo effects induced by monocytes transfected with total RNA were stronger than those induced by monocytes pulsed with tumor cell lysates. CONCLUSION: Antigen presenting cells transfected with total RNA of CT-26 can present endogenous? tumor antigens, activate CTL, and effectively induce specific antitumor immunity.

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

AIM： To generate dendritic cells （DCs） from human peripheral blood and to detect the expression of dendritic cell-specific intercellular adhesion molecule 3 grabbing nonintegrin （DC-SIGN; CD209） for the further study of DC-SIGN in hepatitis C virus （HCV） transmission. METHODS： Peripheral blood monocytes were isolated from blood of healthy individuals by Ficoll--Hypaque sedimentation and cultured in complete medium containing rhGM-CSF and rhIL-4. Cells were cultured for seven days, with cytokine addition every two days to obtain immature DCs. Characteristics of the cultured cells were observed under light and scanning microscope, and the expression of DC-SIGN was detected by immunofluorescence staining. RESULTS： After seven-day culture, a large number of cells with typical characteristics of DCs appeared. Their characteristics were observed under light and scanning electron microscope. These cells had a variety of cell shapes such as those of bipolar elongate cells, elaborate stellate cells and DCs. DC-SIGN was detected by immunofluorescence staining and its expression level on cultivated dendritic cells was high. CONCLUSION： DCs with a high expression of DC-SIGN can be generated from human peripheral blood monocytes in complete medium containing rhGM-CSF and rhIL-4.

Caspase-1 activation and mature interleukin-1β release are uncoupled events in monocytes

AIM:To investigate whether caspase-1 activation/intracellular processing of pro-interleukin-1β(pro-IL-1β) and extracellular release of mature IL-1β from activated monocytes are separable events.METHODS:All experiments were performed on fresh or overnight cultured human peripheral blood monocytes(PBMCs) that were isolated from healthy donors.PBMCs were activated by lipopolysaccharide(LPS) stimulation before being treated with Adenosine triphosphate(ATP,1 mmol/L),human α-defensin-5(HD-5,50 μg/mL),and/or nigericin(Nig,30 μmol/L).For each experiment,the culture supernatants were collected separately from the cells.Cell lysates and supernatants were both subject to immunoprecipitation with anti-IL1β antibodies followed by western blot analysis with anti-caspase-1 and anti-IL-1β antibodies.RESULTS:We found that pro-IL-1β was processed to mature IL-1β in LPS-activated fresh and overnight cultured human monocytes in response to ATP stimulation.In the presence of HD-5,this release of IL-1β,but not the processing of pro-IL-1β to IL-1β,was completely inhibited.Similarly,in the presence of HD-5,the release of IL-1β,but not the processing of IL-1β,was significantly inhibited from LPS-activated monocytes stimulated with Nig.Finally,we treated LPS-activated monocytes with ATP and Nig and collected the supernatants.We found that both ATP and Nig stimulation could activate and release cleaved caspase-1 from the monocytes.Interestingly,and contrary to IL-1β processing and release,caspase-1 cleavage and release was not blocked by HD-5.All images are representative of three independent experiments.CONCLUSION:These data suggest that caspase-1 activation/processing of pro-IL-1β by caspase-1 and the release of mature IL-1β from human monocytes are distinct and separable events.

Expression of Monocyte Chemoattractant Protein-1 in Monocytes and Effects of Native and Oxidized Very Low Density Lipoproteins

Monocyte chemoattractant protein-1(MCP-1), a potent chemoattractant, is thought to play an important role in migration of monocytes into atherosclerotic lesions. The present study was designed to investigate the capacity of human peripheral blood monocytes to express MCP-1 and effects of native very low density lipoprotein (VLDL) and oxidized VLDL(OX-VLDL) on the expression. The total RNA was extracted from cultured monocytes, which were exposed to VLDL and OX-VLDL, and the media conditioned by monocytes were collected. MCP-1 mRNA expression was examined by Northern blot analysis. MCP-1 protein in conditioned media was determined by using sandwich ELISA. The results showed that monocytes can express MCP-1 after a 24 h incubation at 37℃，and the expression was markedly increased by a exposure to OX-VLDL, whereas the expression was slightly increased when exposed to VLDL. It suggests that the capacity of monocytes to produce MCP-1 that recruits and activates circulating monocytes may be of considerable importance in atherogenesis, and oxidation of VLDL enhances its potential to promote atherogenesis.

Single-cell RNA sequencing reveals classical monocytes are the major precursors of rat osteoclasts

To dissect which subset of bone marrow monocyte is the major precursor of osteoclast,3-month-old rat bone marrow was obtained for single-cell RNA sequencing.A total of 6091 cells were acquired for detailed analysis,with a median number of 1206 genes detected per cell and 17,959 genes detected in total.A total of 19 cell clusters were recognized,with the main lineages identified as B cells,Granulocytes,Monocytes,T cells,Erythrocytes and Macrophages.Monocytes were further divided into classical monocytes and non-classical monocytes.Compared with non-classical monocytes,classical monocytes highly expressed osteoclast differentiation related genes Mitf,Spi1,Fos and Csf1r.Additionally,biological processes of classical monocytes were related to osteoclast differentiation.qPCR revealed differentially expressed genes of classical monocytes played a role in osteoclast differentiation.In conclusion,classical monocytes were identified as the main precursors of osteoclasts in rats,and may contribute to osteoclast differentiation by regulating S100a4,S100a6,S100a10,Fn1,Vcan and Bcl2a1.The results of this study contribute to the understanding of the origin of osteoclasts and may provide potential biomarkers for early diagnosis of bone metabolic diseases,as well as molecular and cellular targets for clinical intervention in bone metabolic diseases.

Waist Circumference-dependent Peripheral Monocytes Change after Gliclazide Treatment for Chinese Type 2 Diabetic Patients

Gliclazide used for the treatment of type 2 diabetes mellitus（T2DM） stimulates insulin secretion and influences peripheral blood monocytes.The roles of gliclazide in peripheral monocytes of newly diagnosed T2 DM patients were investigated in this study.A total of 105 newly diagnosed T2 DM patients with no history of antihyperglycemic medication were treated with gliclazide-modified release for 16 weeks.The total and differential leukocyte profiles of peripheral blood were measured at baseline and week 16.The peripheral blood monocyte count at week 16 was significantly lower than that at baseline（P=0.019）.Peripheral monocytes level at baseline was positively correlated with waist circumference.After gliclazide treatment,the peripheral monocytes were decreased [（320.09±15.13）×10~6/L vs.（294.19±14.22）×10~6/L] in non-abdominal obesity group,but increased in abdominal obesity group [（344.36±17.24）×10~6/L vs.（351.87±16.93）×10~6/L].Compared with non-abdominal obese patients,abdominal obese patients showed higher Δmonocytes（P=0.046） and Δacute insulin secretion（P=0.049）,but lower ΔHb A1c（P=0.047）.There was significantly positive correlation between Δmonocytes and Δacute insulin secretion（P=0.015）,which disappeared after adjusting for age,waist circumference and dosage at baseline.In conclusion,waist circumference is correlated with peripheral monocyte change after gliclazide treatment in Chinese newly diagnosed T2 DM patients.Peripheral monocytes are decreased in non-abdominal obesity group and increased in abdominal obesity group after gliclazide treatment.