Leishmania infantum induces high phagocytic capacity and intracellular nitric oxide production by human proinflammatory monocyte

BACKGROUND The mechanism of resistance to SbIII in Leishmania is complex, multifactorial and involves not only biochemical mechanisms, but also other elements, such as the immune system of the host. OBJECTIVES In this study, putative changes in the immunological profile of human monocytes infected with wild-type (WT) and antimony (SbIII)-resistant Leishmania (Viannia) braziliensis and Leishmania (Leishmania) infantum lines were evaluated. METHODS Susceptibility assays WT and SbIII-resistant L. braziliensis and L. infantum were performed using lines THP-1 human monocytic lineage. Phagocytic capacity, cytokine profile, intracellular nitric oxide (NO) production and surface carbohydrate residues profile were performed in peripheral blood monocytes by flow cytometry. FINDINGS The phagocytic capacity and intracellular NO production by classical (CD14++CD16-) and proinflammatory (CD14++CD16+) monocytes were higher in the presence of L. infantum lines compared to L. braziliensis lines. The results also highlight proinflammatory monocytes as the cellular subpopulation of major relevance in a phagocytosis event and NO expression. It is important to note that L. infantum induced a proinflammatory cytokine profile characterised by higher levels of TNF-α in culture supernatant than L. braziliensis. Conversely, both Leishmania lines induce high levels of IL-6 in culture supernatant. Analysis of the expression profile of surface carbohydrates showed that L. braziliensis presents 4.3-fold higher expression of galactose(β1,4)N-acetylglucosamine than L. infantum line. Interestingly, the expression level of α-N-acetylgalactosamine residues was 2-fold lower in the SbIII-resistant L. braziliensis line than its counterpart WT line, indicating differences in surface glycoconjugates between these lines. MAIN CONCLUSIONS Our results showed that L. braziliensis and L. infantum induce different innate immune responses and a highly inflammatory profile, which is characteristic of infection by L. infantum, the species associated with visceral disease.

Expression and significance of CD64 on monocyte subsets from patients with rheumatoid arthritis / 中国免疫学杂志

Objective:To investigate the expression of CD64 on monocyte subset from patients with rheumatoid arthritis (RA) and its significance and to clarify its role in the development of RA.Methods:The peripheral blood from 44 patients and 22 healthy controls (HC)were collected,the proportions of each monocyte subset and the CD64 expression on monocyte subsets were detected by flow cytometry.The proportions of each monocyte subset and the expression of TIGIT on monocyte subsets were compared between RA patients and HC.The correlations of CD64 expression on monocyte subsets with laboratory index were analyzed.The data were statistically analyzed.Results:(1)The proportion of intermediate monocytes in patients with RA was significantly higher than that in healthy volunteers (P＜0.01),while the proportion of classical and nonclassical monocytes in patients with RA was significantly lower than that in healthy volunteers (P＜0.05).(2) The expression of CD64 (MFI) on monocyte subsets were significantly elevated in RA patients compared to healthy volunteers (P＜0.05).(3)The expression of CD64 on classical monocytes and intermediate monocytes were positively correlated with DAS28 score (rs =0.308,P =0.044;rs =0.302,P =0.049).(4) The expression of CD64 (MFI) on monocyte subsets were positively correlated with ESR and CRP (rs =0.410,P=0.008;rs =0.475,P=0.003;rs =0.448,P=0.003;rs =0.473,P =0.004;rs =0.348,P =0.026;rs =0.340,P =0.042).(5) The expression of CD64 on classical monocytes and intermediate monocytes were significantly increased in patients with positive RF and ACPA respectively (P＜0.05).(6)The RA patients with high levels of CD64 on intermediate monocytes exhibited significantly higher levels of IL-6 compared with the RA patients with low levels of D64 on intermediate monocytes (P＜0.05).Conclusion:In RA,the expression of CD64.on monocyte subsets are elevated,and the expression of CD64 on classical monocytes and intermediate monocytes associated with the inflammatory markers,the production of antibodies and the disease activity.In addition,the expression of CD64 on intermediate monocytes associated with cytokine.

Expression of LP-PLA2 mRNA in peripheral blood monocytes subsets of patients with type 2 diabetes mellitus / 中华内分泌代谢杂志

Objective To investigate the role of monocyte subsets in the pathogenesis of type 2 diabetes mellitus(T2DM), the expression was detected on lipoprotein-associated phospholipase A2(LP-PLA2) mRNA in peripheral blood monocytes subsets of type 2 diabetic patients. Methods After the peripheral blood of 32 type 2 diabetic patients and 22 healthy controls were collected,the percentages of the monocytes subsets were detected by flow cytometry. The expression of LP-PLA2 mRNA in monocytes subsets were detected by PCR. After monocyte subsets of healthy subjects were induced into macrophages and stimulated by the serum of type 2 diabetic patients for 24h,LP-PLA2 mRNA expression was detected. Results Compared with the control group, the percentage of classical monocytes in T2DM group was decreased, while the LP-PLA2 mRNA expression and percentage of nonclassical,intermediate monocytes were significantly increased(all P<0.05). In addition,the homeostasis model assessment for insulin resistance index was positively correlated with LP-PLA2 mRNA expression in non-classical(P<0.05)and intermediate monocytes(P<0.01)of type 2 diabetic patients. Compared with type 2 diabetic patients without carotid atherosclerosis, the levels of LP-PLA2 mRNA in intermediate and nonclassical monocytes were significantly higher than those in type 2 diabetic patients with carotid atherosclerosis(P<0.05). The level of LP-PLA2 mRNA in non-classical monocytes-derived macrophages stimulated with the serum of type 2 diabetic patients was significantly higher than that in the control group(P<0.05). Conclusion Monocytes subsets from type 2 diabetic patients are abnormally skewed toward to intermediate and non-classical monocytes with high expression of LP-PLA2 mRNA,which may play an important role in the pathogenesis of type 2 diabetes mellitus and atherosclerosis.

Characteristic of peripheral blood monocyte subsets and chemokines in early stage of acute coronary syndrome / 复旦学报（医学版）

Objective To investigate the expression of monocyte subsets and their chemokine,i.e.,monocyte chemoattractant protein (MCP-1) and fractalkine (FKN),in patients with acute coronary svndrome (ACS),and to analyze their correlation.Methods Patients with the syndrome of pectoralgia and to be inspected with coronary angiography (CAG) in our hospital from Sep.to Dec.,2016 were included.Patients' venous blood was collected on the operation day before operation,the level and proportion of monocyte (Mon) subsets,which was namely CD14 + CD16-Mon (Mon1),CD14+CD16 + Mon (Mon2) and CD14-CD16 + Mon (Mon3) according to the expression of cluster differentiation-14 (CD14) and CD16,were detected by flow cytometry (FCM).Patients' venous blood was collected on the operation day before operation and one day after operation,the concentrations of MCP-1 and FKN in plasma were measured by ELISA.We compared the expression levels of MCP-1-Mon1 and FKN-Mon3,and analyzed their relationship between each other respectively in different groups.Results Diagnosed according to the clinical symptoms,myocardial markers,electrocardiogram and CAG results,70 individuals were analyzed,including 30 patients with acute myocardial infarction (AMI group),25 patients with unstable angina pectoris (UAP group) and 15 patients with the chest pain symptoms and normal CAG results (control group).The percentage of Mon1 in the AMI group was higher than that in the other groups (P＜0.05);no difference was observed for Mon3 among the groups (P＞0.05).The Mon3/Mon1 ratio in the AMI group was lower than that in the control group (P＜0.05).Moreover,the levels of FKN and MCP-1 in the ACS group were greater than those in the control group.The level of red blood cell distribution width (RDW) was significantly increased in the AMI and UAP group than that in the control group (P＜0.05).There was a significant correlation between FKN and Mon3 (P＜0.05,R=0.650 2).Conclusions The monocyte subset of Mon1 and Mon3 increased in the early stage of ACS,with their chemokine (FKN and MCP-1) increasing at the same time.There is a significant correlation between FKN and Mon3,which indicates MCP-1-Mon1 and FKN-Mon3 may participate in the pathophysiological process of early ACS in patients.

Abnormality and significance of monocyte subsets in peripheral blood of patients with rheumatoid arthritis / 中国免疫学杂志

Objective:To explore the role of peripheral blood monocyte subsets in the pathogenesis of rheumatoid arthritis (RA),we therefore decided to compare the percentage of monocyte subpopulations in peripheral blood,as well as cytokines secretion function,to that of healthy controls. Methods:22 patients with RA and 22 cases of healthy controls ( HC) were drew 3 ml fresh venous blood into a tube containing heparin. The percentage of monocyte subsets,expression of Toll-like receptor(TLR)2,HLA-DR,triggering receptor expressed on myeloid cells-1(TREM-1) on intermediate monocyte and mean fluorescence intensity(MFI) of intracellular tumor necrosis factor-α ( TNF-α) were evaluated with the methods of flow cytometry ( FCM ) . The correlation between percentage of monocyte subsets and serum cytokines was explored. Statistical significance between parametric data was determined by the students't-test. Results:Compared to HC controls, the percentages of intermediate monocytes were significant higher in RA patients [ ( 11. 7 ± 1. 6)% vs (4. 6±1. 2)%,P0. 05),while MFI of intracellular TNF-αin intermediate monocytes of RA patients were significant higher than that of HC controls (46. 3±6. 4 vs 36. 7±8. 3,P<0. 05). In addition,RA patients showed a positive correlation between the percentage of CD14highCD16+ monocytes and DAS28 scores(r=0. 538,P=0. 009),as well as the serum levels of TNF-α,IL-17 ( r=0. 471,P=0. 027;r=0. 593,P=0. 003). Conclusion:Monocyte subpopulations from RA patients are abnormally skewed toward to in-termediate monocytes which has high expression of TLR2 , TREM-1 and the function of TNF-α secretion. Therefore, intermediate monocytes may play a role in the pathophysiology of RA. By modulating polarization or blocking monocyte cell surface receptors could be a new treatment of RA.