羧胺三唑抑制肿瘤细胞诱导的巨噬细胞中肿瘤坏死因子-α的释放

目的观察体外培养的肿瘤细胞对巨噬细胞炎症因子——肿瘤坏死因子-α(TNF-α)的诱导作用;初步探索羧胺三唑(CAI)对肿瘤诱导的巨噬细胞中TNF-α释放的影响。方法利用transwell装置,建立Lewis肺癌细胞(LLC)与RAW264.7巨噬细胞共培养体系,采用荧光定量PCR方法和ELISA方法分别分析RAW264.7中TNF-α的表达和释放;用LLC条件培养基(LCM)诱导RAW264.7,同时给予CAI处理,采用CCK-8方法分析LCM和CAI对RAW264.7活力的影响,采用ELISA方法分析CAI对诱导后的RAW264.7中TNF-α释放的影响。结果与LLC共培养24 h可显著增加RAW264.7中TNF-α相对表达量[单独培养vs共培养,(1.00±0.12)vs(2.23±0.17),P<0.01]和释放[单独培养vs共培养,(65.21±12.76)vs(143.92±19.22)pg/ml,P<0.05];LCM和CAI在1 h和4 h对RAW264.7活力没有影响,CAI可以显著抑制LCM对RAW264.7中TNF-α释放的诱导(4 h,P<0.01)。结论 LLC肿瘤微环境可以诱导RAW264.7中TNF-α的表达增加;CAI对这种诱导的抑制使其在肿瘤环境中表现出一定的抗炎作用,可能是其抗肿瘤作用的机制之一。     

Imperatorin Attenuates LPS-Induced Inflammation by Suppressing NF-κB and MAPKs Activation in RAW 264.7 Macrophages

Imperatorin is a type of coumarin compound with antibacterial and antiviral activities. In the present study, we examined the anti-inflammatory effects of imperatorin in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages by investigating its impact on the production and expression of cytokines and the major signal-transduction pathways. We found that imperatorin downregulated LPS-induced levels of TNF-??, IL-1??, and IL-6 in RAW 264.7 macrophages in a concentration-dependent manner, and it significantly inhibited expression of TNF-?? and IL-6 (P?<?0.05 or P?<?0.01). The phosphorylation of mitogen-activated protein kinases and nuclear factor-kappaB (NF-??B) p65 protein were analyzed by western blotting. In RAW 264.7 macrophages treated with 1?mg/L of LPS, imperatorin significantly inhibited p38 and Jun N-terminal kinase phosphorylation protein expression. However, there was no significant change in p-ERK. Furthermore, imperatorin also inhibited NF-??B translocation into the nucleus through blockage of I??B?? phosphorylation and degradation.     

Macrophages produce IL-33 by activating MAPK signaling pathway during RSV infection

It has been reported that RSV infection can enhance IL-33 production in lung macrophages. However, little is known about specific signaling pathways for activation of macrophages during RSV infection. In the present study, by using real-time RT-PCR as well as western blot assay, it became clear that RSV infection can enhance not only the expression of mRNAs for MAPK molecules (including p38, JNK1/2, and ERK1/2), but also the levels of MAPK proteins in lung macrophages as well as RAW264.7 cells. Furthermore, infection with RSV resulted in an increased level of phosphorylated MAPK proteins in RAW264.7 cells, suggesting that MAPK signaling pathway may participate in the process of RSV-induced IL-33 secretion by macrophages. In fact, the elevated production of IL-33 in RAW264.7 was attenuated significantly by pretreatment of the cells with special MAPK inhibitor before RSV infection, further confirming the function of MAPKs pathway in RSV-induced IL-33 production in macrophages. In contrast, the expression of NF-κB mRNA as well as the production of NF-κB protein in lung macrophages and RAW264.7 cells was not enhanced markedly after RSV infection. Moreover, RSV infection failed to induce the phosphorylation of NF-κB in RAW264.7 cells, suggesting that NF-κB signaling pathway may be not involved in RSV-induced IL-33 production in macrophages. Conclusion, these results indicate that RSV-induced production of IL-33 in macrophages is dependent on the activation of MAPK signaling pathway.     

葫芦素E对脂多糖诱导RAW264.7巨噬细胞炎症反应的影响及作用机制

分析葫芦素E(CuE)对脂多糖(LPS)诱导的小鼠RAW264.7巨噬细胞炎症反应的影响,研究其抗炎作用的分子机制。采用改良MTT法检测RAW264.7细胞的增殖;以碘化丙锭染色检测CuE对细胞周期的影响;采用细胞内细胞因子染色法分析肿瘤坏死因子(TNF-α)的表达;免疫荧光染色分析胞内Actin的结构;应用免疫印迹法检测CuE对G-肌动蛋白(G-ac-tin)及核转录因子NF-κB核转位的影响。实验结果显示CuE对RAW264.7细胞的增殖具有剂量依赖性抑制作用,并降低细胞内G-actin的水平;CuE明显阻止LPS诱导的细胞伸展和伪足形成,使细胞周期阻滞于G2/M期。同时,CuE还明显抑制LPS活化的RAW264.7细胞表达促炎因子TNF-α,并显著降低LPS诱导的转录因子NF-κB的核转位作用。这些结果表明,CuE通过破坏RAW264.7巨噬细胞的肌动蛋白细胞骨架,引起细胞周期阻滞,并抑制LPS诱导的NF-κB核转位以及TNF-α的表达,从而发挥抗炎作用。     

香菇茯苓银耳复合多糖对小鼠巨噬细胞功能的作用研究

目的：研究香菇茯苓银耳复合多糖对不同状态下巨噬细胞功能的调节作用。方法：将巨噬细胞株RAW264.7细胞分别与复合多糖（CP）、复合多糖联合LPS（CP+LPS）、复合多糖预孵育后联合LPS（Pre-CP+LPS）共孵育,采用荧光显微镜和流式细胞仪检测RAW264.7细胞吞噬荧光微球情况;采用Griess试剂检测RAW264.7细胞分泌NO水平;采用流式细胞术检测巨噬细胞表面活化标志物CD40、CD80和CD86的表达水平。结果：RAW264.7细胞与复合多糖共孵育条件下,复合多糖可以增强RAW264.7细胞对荧光微球的吞噬作用,且随着时间的延长愈加明显;复合多糖低浓度对RAW264.7细胞分泌NO无影响,当浓度达1 000 μg/ml时才能促进其显著分泌NO;复合多糖可以提高RAW264.7细胞CD40、CD80和CD86分子表达水平。在LPS刺激条件下,复合多糖联合LPS与复合多糖预孵育后联合LPS两种处理都可以减轻LPS导致的CD40、CD80和CD86活化标志过表达现象。结论：复合多糖对不同状态下巨噬细胞功能具有调节作用,即可以促进静息状态下巨噬细胞活化和吞噬作用,而对活化状态的巨噬细胞功能具有抑制作用。     

肾上腺素对小鼠巨噬细胞中促炎／抗炎介质比值的影响

目的：研究肾上腺素对脂多糖（LPS）诱导的小鼠单核巨噬细胞株RAW264.7中促炎介质［肿瘤坏死因子（TNF-α）、一氧化氮（NO）、环加氧酶-2（COX-2）］和抗炎介质［血红素氧化酶-1（HO-1）、白介素10（IL-10）］表达及NF-κB活化的影响。 方法： 以10 μg/L的LPS刺激体外培养的RAW264.7细胞作为炎症模型，加入不同浓度的肾上腺素（1、5、10、50 μmol/L）孵育24 h后，收集培养上清并提取细胞总蛋白，酶联免疫法测定上清中TNF-α、IL-10浓度，Griess法检测上清NO含量(以NO2-/NO3-表示)，免疫印迹法检测细胞总蛋白中COX-2、HO-1、IκB-α的含量。 结果： 10 μg/L的LPS明显诱导TNF-α、NO(NO2-/NO3-)、COX-2、IL-10及HO-1的产生；LPS+肾上腺素组与LPS单独作用组相比促炎介质TNF-α、NO(NO2-/NO3-)、COX-2的表达量显著下降，而抗炎介质IL-10、HO-1的表达却明显增强；肾上腺素与LPS共同作用组中IκB-α的含量与单独LPS作用组相比无明显差异。 结论： 肾上腺素下调LPS诱导的巨噬细胞中促炎介质的表达同时促进抗炎介质的表达，这种效应并不通过影响NF-κB的活化来实现。     

Up-regulation of growth factor independence 1 in endotoxin tolerant macrophages with low secretion of TNF-α and IL-6

Objective

Endotoxin tolerance refers to a low response to lipopolysaccharide (LPS). We hypothesized that growth factor independence 1 (Gfi1) involves in the endotoxin tolerance in macrophages.

Methods

Endotoxin tolerance was induced in the RAW264.7 cell line and thioglycolate-elicited murine peritoneal macrophages by incubation with 100 ng/ml LPS for 20 h. Macrophages without the pretreatment were set as control. Both endotoxin tolerant and control cells were then stimulated with 1,000 ng/ml LPS for indicated period of incubation. Gfi1 mRNA expression and protein production were investigated by real-time PCR and Western blotting, respectively. ELISA was performed to quantify the secretion of TNF-α and IL-6.

Result

Compared with non-endotoxin tolerant macrophages, endotoxin tolerant cells secreted a lower amount of TNF-α and IL-6. The mRNA expression of Gfi1 in endotoxin tolerant macrophages was higher than that of control in both RAW264.7 cells and thioglycolate-elicited murine peritoneal macrophages. The protein production was accordingly up-regulated in endotoxin tolerant RAW264.7 cells.

Conclusion

In in vitro endotoxin tolerant macrophages, the expression of Gfi1 mRNA and protein were up-regulated after high dose LPS stimulation, accompanied with a blunted TNF-α and IL-6 secretion. Gfi1 might participate in the mechanism of endotoxin tolerance.     

Direct Effects of Activin A on the Activation of Mouse Macrophage RAW264.7 Cells

Macrophages play critical roles in innate immune and acquired immune v/a secreting pro-inflammatory mediators, phagocytosing microorganisms and presenting antigens. Activin A, a member of transforming growth factor （TGF-β） superfamily, is produced by macrophages and microglia cells. In this study, we reported a direct effect of activin A as a pro-inflammatory factor on mouse macrophage cell line RAW264.7 cells. Our data revealed that activin A could not only increase IL-1β and IL-6 production from RAW264.7 cells, but also promote pinocytic and phagocytic activities of RAW264.7 cells. In addition, activin A obviously up-regulated MHC Ⅱ expression on the surface of RAW264.7 cells, whereas did not influence MHC I expression. Activin A also enhanced CD80 expression, which is a marker of activated macrophages, but did not influence RAW264.7 cell proliferation. These data suggest that activin A may regulate primary macrophage-mediated innate and acquired immune response via promoting the activation of rest macrophages.     

Bidirectional Immunomodulatory Activities of Polysaccharides Purified From Pleurotus nebrodensis

A novel Pleurotus nebrodensis polysaccharide (PN50G) was purified, characterized, and cultured with RAW264.7 macrophages to evaluate its bidirectional immunostimulating characteristics. PN50G was purified by using Sepharose 4B gel filtration; the molecular weight of PN50G was distributed at 2,000 kDa. The total protein and carbohydrate constituent ratios in PN50G were 2.6?±?0.9 % and 92.4?±?6.1 % (w/w), respectively, which suggests that PN50G may be a major proteo-polysaccharide component. The phagocytosis of macrophages was improved significantly, and remarkable changes were observed in the morphology of PN50G-treated cells. Compared with the control group, the productions of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and inducible nitric oxide synthase (iNOS) in the macrophages as well as the messenger RNA expressions were strongly induced by PN50G. Pro-/anti-inflammatory (IL-6/IL-10, TNF-α/IL-10, NO/IL-10) cytokine secretion ratios by lipopolysaccharide-stimulated RAW264.7 macrophages were significantly decreased by PN50G treatments in a dose-dependent manner under an excessive immune experimental model. This study suggests that purified PN50G can improve immunity and suppress immune overactivity in LPS-induced macrophages in a preventive manner to coordinate innate immunity and inflammatory responses.     

Functional expression of Nramp1 in vitro in the murine macrophage line RAW264.7

Mutations at the Nramp1 locus in vivo cause susceptibility to infection by unrelated intracellular microbes. Nramp1 encodes an integral membrane protein abundantly expressed in the endosomal-lysosomal compartment of macrophages and is recruited to the phagosomal membrane following phagocytosis. The mechanism by which Nramp1 affects the biochemical properties of the phagosome to control microbial replication is unknown. To devise an in vitro assay for Nramp1 function, we introduced a wild-type Nramp1(G169) cDNA into RAW 264.7 macrophages (which bear a homozygous mutant Nramp1(D169) allele and thus are permissive to replication of specific intracellular parasites). Recombinant Nramp1 was expressed in a membranous compartment in RAW264.7 cells and was recruited to the membrane of Salmonella typhimurium and Yersinia enterocolitica containing phagosomes. Evaluation of the antibacterial activity of RAW264.7 transfectants showed that expression of the recombinant Nramp1 protein abrogated intracellular replication of S. typhimurium. Studies with a replication-defective S. typhimurium mutant suggest that this occurs through an enhanced bacteriostatic activity. The effect of Nramp1 expression was specific, since (i) it was not seen in RAW264.7 transfectants overexpressing the closely related Nramp2 protein, and (ii) control RAW264.7 cells, Nramp1, and Nramp2 transfectants could all efficiently kill a temperature-sensitive, replication-defective mutant of S. typhimurium. Finally, increased antibacterial activity of the Nramp1 RAW264.7 transfectants was linked to increased phagosomal acidification, a distinguishing feature of primary macrophages expressing a wild-type Nramp1 allele. Together, these results indicate that transfection of Nramp1 cDNAs in the RAW264.7 macrophage cell line can be used as a direct assay to study both Nramp1 function and mechanism of action as well as to identify structure-function relationships in this protein.     

TGF-β1下调炎性巨噬细胞RAW264.7 TLR4受体的表达

目的探讨TGF-β1对小鼠巨噬细胞RAW264.7 TLR4受体表达的调节作用。方法 Teal-Time PCR法检测RAW264.7细胞TGF-β1和TLR4受体mRNA表达,ELISA法检测RAW264.7细胞TGF-β1的分泌,流式细胞术检测RAW264.7细胞TLR4受体的表达。结果一定剂量的LPS促进RAW264.7分泌TGF-β1,且呈剂量依赖关系,一定剂量的TGF-β1单独刺激下调RAW264.7的TLR4受体的表达,TGF-β1能够下调LPS活化的RAW264.7细胞TLR4受体表达。结论 TGF-β1可以通过下调巨噬细胞TLR4受体表达来控制机体炎性反应,这可能是TGF-β1作为免疫抑制剂抑制炎症反应的重要途径之一。     

氧化剂对RAW264.7细胞M-CSF

目的:揭示氧化应激对巨噬细胞巨噬细胞集落刺激因子(M-CSF)基因表达的影响。方法:采用逆转录多聚酶链反应(RT-PCR)技术,观察氧化剂叔丁基氢过氧化物(tbOOH)对RAW264.7细胞M-CSF mRNA表达的影响。结果:一定浓度的tbOOH(1.5×10^-4 mol/L)能够诱导RAW264.7细胞M-CSF mRNA表达,且随tbOOH浓度的增加,其对M-CSF mRNA的诱导作用增强;另外,环己酰亚胺(cycloheximide)及acetovanilone可减弱tbOOH对RAW264.7细胞M-CSF表达的诱导。结论:tbOOH可诱导RAW264.7细胞M-CSF mRNA的表达,且作用在转录水平,该过程中有新的蛋白质合成及内源性活性氧产生的参与。     

Bacterial Cell Wall Constituents Induce Hepcidin Expression in Macrophages Through MyD88 Signaling

Hepcidin is a key regulator of iron recycling by macrophages that is synthesized mainly by hepatocytes but also by macrophages. However, very little is known about the molecular regulation of hepcidin in macrophages. In the present study, we investigated hepcidin regulation in the RAW264.7 macrophage cell line and in murine peritoneal macrophages stimulated with different Toll-like receptor (TLR) ligands. We found that TLR-2 and TLR-4 ligands activated hepcidin expression in RAW264.7 cells and in wild-type murine peritoneal macrophages, but not in murine peritoneal macrophages isolated from TLR2(-/-), TLR-4-deficient or MyD88(-/-) mice. IL-6 production by RAW264.7 cells stimulated with lipopolysaccharide (LPS, TLR4 ligand) was enhanced by high amounts of iron present in the culture medium. We conclude that hepcidin expression in macrophages is regulated mainly through TLR2 and TLR4 receptors via the MyD88-dependent signaling pathway and that autocrine regulation of iron accumulation in macrophages by hepcidin may affect the levels of proinflammatory cytokine production.     

Upregulation of heme oxygenase-1 via PI3K/Akt and Nrf-2 signaling pathways mediates the anti-inflammatory activity of Schisandrin in Porphyromonas gingivalis LPS-stimulated macrophages

The lipopolysaccharide (LPS) of Porphyromonas gingivalis is thought to induce periodontitis. In this study, we isolated Schisandrin from the dried fruits of Schisandra chinensis and examined the anti-inflammatory effect of Schisandrin in macrophages stimulated with LPS from P. gingivalis. First, Schisandrin inhibited LPS-induced pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6. And Schisandrin suppressed the nuclear translocation and activity of NF-κB and phosphorylation of IκBα in LPS-stimulated RAW 264.7 cells. Next, the presence of a selective inhibitor of HO-1 (SnPP) and a siRNA specific for HO-1 inhibited Schisandrin-mediated anti-inflammatory activity. Furthermore, Schisandrin induced HO-1 expression of RAW 264.7 cells through Nrf-2, PI3K/Akt, and ERK activation. Therefore, these results suggest that the anti-inflammatory effects of Schisandrin on P. gingivalis LPS-stimulated RAW 264.7 cells may be due to a reduction of NF-κB activity and induction of the expression of HO-1, leading to TNF-α, IL-1β, and IL-6 down-regulation.     

Alcohol extracts of Echinacea inhibit production of nitric oxide and tumor necrosis factor-alpha by macrophages in vitro

It has been suggested that Echinacea has anti-inflammatory activity in vivo. Nitric oxide (NO), tumor necrosis factor-alpha (TNF-α), and interleukin-1beta are important mediators in the inflammatory response. The effect of alcohol extracts of E. angustifolia (EA), E. pallida (EPA) and E. purpurea (EP) on the production of these inflammatory mediators in both LPS-stimulated RAW 264.7 macrophages in vitro and murine peritoneal exudate cells (PECs) in vivo were investigated. As macrophages produce these inflammatory mediators in response to pathogenic infection, parallel cultures of macrophages were studied for phagocytosis and intracellular killing of Salmonella enterica. EPA and EP in vitro inhibited NO production and TNF-α release in a dose-dependent manner. RAW 264.7 cells treated with EA or EP showed decreased killing over 24 h, although EA enhanced bacterial phagocytosis. Upon bacterial infection, RAW 264.7 cells produce high levels of NO; however, an Echinacea-mediated decrease in NO production was observed. Echinacea alcohol extracts administered orally at 130 mg/kg per day for seven days had a weak effect on NO production and phagocytosis by LPS-stimulated PECs. The results indicated that all Echinacea species significantly decreased inflammatory mediators in vitro, however, only EA and EP reduced bacterial killing. Oral administration of Echinacea alcohol extracts did not adversely affect the development and anti-bacterial function of inflammatory PECs in vivo, however, NO production was decreased during bacterial infection of PECs.     

黄芩抗内毒素组分的制备及其生物学活性研究

目的:研究从黄芩中分离提取拮抗内毒素(LPS)组分的制备方法及其生物学活性。方法:采用大孔吸附树脂AB-8将黄芩水提物分离成若干组分,应用生物传感器技术检测各组分与LPS的活性中心LipidA的结合活性,ELISA法检测各组分对LPS刺激RAW264.7细胞释放肿瘤坏死因子α(TNF-α)的影响;由此筛选出能与LipidA结合并对LPS刺激的RAW264.7细胞活化具有抑制作用的组分,进一步观察所得组分对脓毒血症模型动物的保护作用。结果:采用大孔吸附树脂AB-8从黄芩中共分离到5种组分(SbG-1～5),其中SbG-4、SbG-5与LipidA具有较高结合活性,特异性结合值(RU)分别为113.36arc/s、73.75arc/s;SbG-4、SbG-5(100mg/L)可显著抑制LPS(100μg/L)诱导的RAW264.7细胞释放TNF-α(P<0.05);SbG-4能显著提高热灭活大肠杆菌(1.33×1011CFU/Kg)所致脓毒血症小鼠的72h存活率(P<0.05),并呈剂量效应关系。结论:从黄芩中分离提取的具有拮抗LPS活性的SbG-4可抑制LPS刺激的RAW264.7细胞活化,并对脓毒血症模型动物具有显著的保护作用。     

Inhibition of Titanium Particle-Induced Inflammation by the Proteasome Inhibitor Bortezomib in Murine Macrophage-Like RAW 264.7 Cells

Wear particle-induced inflammatory osteolysis is the major cause of aseptic loosening after total joint replacement. The predominant cell type within periprosthetic tissues is macrophages. We investigate the anti-inflammatory effects of the proteasome inhibitor bortezomib (Bzb) on murine macrophage-like RAW 264.7 cells stimulated with titanium (Ti) particles. RAW 264.7 cells were cultured with 1 nM Bzb and 0.1 mg/ml Ti particles for 48 h; cells without Ti and Bzb or without Bzb were used as negative and loading controls. Results showed that the expression of inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-10), chemokines [monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1α)], and inflammatory enzymes [inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2)] increased in RAW 264.7 cells cultured with Ti. Bzb treatment significantly reduced the expression of TNF-α, IL-1β, IL-6, MCP-1, MIP-1α, iNOS, and COX-2 and induced the expression of IL-10 in a time-dependent manner. These results suggest that Bzb inhibits Ti-induced inflammation in macrophages, and provide a promising therapeutic target for treating or preventing aseptic loosening.     

NLRC5 Mediates Cytokine Secretion in RAW264.7 Macrophages and Modulated by the JAK2/STAT3 Pathway

The nucleotide-binding domain leucine-rich repeat proteins (NLRs), a class of innate immune receptors that respond to pathogen attack or cellular stress, have gained increasing attention. NLRC5 is the largest member of NLR family, which has recently been identified as a critical regulator of immune responses. In this study, we explore the role of NLRC5 in cytokine secretion and the role of the JAK2/STAT3 signaling pathway in lipopolysaccharide-induced NLRC5 expression in RAW264.7 cells. We demonstrated that overexpression of NLRC5 results in a downregulation of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) secretion; on the other hand, knockdown of NLRC5 by transfecting siRNA enhanced IL-6 and TNF-α secretion in RAW264.7 cells. These results indicated that NLRC5 plays a negative role in the regulation of IL-6 and TNF-α. Meanwhile, AG490 (a specific inhibitor of the JAK2/STAT3 signaling pathway) and JAK2 siRNA were used to manipulate JAK2/STAT3 activity. Finally, the results showed that AG490 and JAK2 siRNA inhibited NLRC5 expression and the expression levels of p-JAK2 and p-STAT3. We, for the first time, demonstrate that the inhibition of the JAK2/STAT3 signaling pathway results in decrease of NLRC5 expression.     

小鼠巨噬细胞内表达结核分枝杆菌CFP10-ESAT6融合蛋白对细胞增殖和凋亡的影响

 目的：建立培养滤液蛋白10-早期分泌性抗原靶6（CFP10-ESAT6）真核表达质粒并转染RAW2647巨噬细胞,观察胞内表达CFP10-ESAT6对细胞活性及凋亡的影响,并初步探讨其机制。方法：将CFP10-ESAT6融合基因插入真核表达质粒pEGFP-N1,构建重组质粒,转染RAW264.7巨噬细胞。采用MTT的方法测定CFP10-ESAT6融合蛋白对RAW264.7巨噬细胞活性的影响,采用结核分枝杆菌19 kD脂蛋白和十字孢碱（staurosporine）处理RAW264.7巨噬细胞,并以流式细胞术检测细胞凋亡率以及Toll样受体2（TLR2）的表达。结果：成功构建了重组质粒pEGFP-N1/CFP10-ESAT6并转染至RAW264.7巨噬细胞;与对照组相比,胞内表达CFP10-ESAT6不能影响巨噬细胞的活性,但可以明显抑制结核分枝杆菌19 kD脂蛋白所造成的凋亡(P＜0.05),并显著抑制了TLR2的表达(P＜0.05)。结论：巨噬细胞内表达的CFP10-ESAT6融合蛋白不具有细胞毒性作用,但可以通过下调TLR2的表达来抑制结核分枝杆菌19 kD脂蛋白所造成的凋亡。