Effect of lipoteichoic acid on IL-2 and IL-5 release from T lymphocytes in asthma and COPD

Susceptibility to infections with gram-positive bacteria, which are an important trigger of exacerbations, is increased in COPD and asthma. Unraveling the underlying mechanisms may help developing therapeutic strategies to reduce exacerbation rates. The aim of this study was to evaluate the effects of lipoteichoic acid (LTA), a danger signal from gram-positive bacteria, on T cell cytokines related to bacterial infection defense in COPD and asthma. T cell populations within peripheral blood mononuclear cells (PBMCs) were ex-vivo activated towards T(H)2/T(C)2 subtypes and subsequently stimulated with LTA. IL-2 and IL-5 concentrations in cell culture supernatants were measured by ELISA comparative between non-smokers (NS), current smokers without airflow limitation (S), smokers with moderate to severe COPD and mild to moderate asthmatics (A) (each n=10). IL-2 and IL-5 baseline levels were without differences between the cohorts. After T cell activation, IL-2 and IL-5 releases were increased in all cohorts, however, for IL-2 this increase was significantly higher in S and by trend in COPD compared to the other groups. LTA time-dependently suppressed IL-2 release in NS, S and COPD but not in A. LTA reduced IL-5 release in COPD and A but not in NS and S. Summarized, LTA reduces T(H)2/T(C)2 cytokines indicating immunosuppressive effects, which are dysregulated in COPD and asthma. This implies a misguided response to gram-positive bacterial infections, which might help to explain the increased susceptibility to bacterial infections in COPD and asthma.     

CD4＋T淋巴细胞分选方法的效果评价

目的 建立一种准确且对细胞活性影响小的分离人外周血CD4＋T细胞的分选方法.方法 对人外周血依次采用密度梯度离心（density gradient centrifugation,DGC）和免疫磁珠分选（magnetic-activated cell sorting,MACS）进行CD4＋T细胞分选.分选后的细胞用流式细胞仪（flow cytometry,FCM）、倒置显微镜及细胞周期分析进行分选纯度和生长状态检测.结果 Percoll密度梯度离心法收集的单个核细胞中CD4＋T细胞纯度为（38.8±2.7）％,免疫磁珠分选后CD4＋T细胞纯度为（96.2±0.7）％,两者比较差异有统计学意义（P＜0.01）,且分选后细胞形态及功能完好,24 h内活性最高.结论 密度梯度离心和免疫磁珠分选相结合可以有效提高CD4＋T细胞的分选纯度及保持其活性,可继续用于相关功能研究.     

特异性免疫治疗对哮喘大鼠白细胞介素-10和CD_4~＋CD_（25）~＋调节性T细胞的影响

目的：探讨特异性免疫治疗（specific immunotherapy,SIT）对哮喘大鼠白细胞介素-10（IL-10）和CD4＋CD25＋调节性T细胞（CD4＋CD25＋Tr）的影响。方法：40只健康雄性清洁级Wistar大鼠随机均分成正常对照组、哮喘组、SIT对照组和SIT治疗组,每组10只。通过卵蛋白（OVA）雾化吸入的方法对致敏大鼠进行SIT干预,观察各组支气管肺泡灌洗液（BALF）中细胞分类及计数结果、血清和BALF中IL-10水平及外周血CD4＋CD25＋Tr百分率变化。结果：正常对照组BALF和血清中IL-10浓度分别高于哮喘组和SIT对照组（均为P〈0.01）,哮喘组和SIT对照组BALF和血清中IL-10浓度低于SIT治疗组（P〈0.01,P〈0.05）;正常对照组外周血CD4＋CD25＋Tr百分率显著高于哮喘组、SIT对照组和SIT治疗组（P〈0.01）,而SIT治疗组CD4＋CD25＋Tr百分率分别高于哮喘组和SIT对照组（P〈0.05）。结论：通过上调体内IL-10和CD4＋CD25＋Tr趋于正常状态可能是SIT治疗哮喘有效的重要机制。     

CD4+IL-10+调节性T细胞在特应性皮炎患者中的改变

摘要 目的 探讨特应性皮炎患者CD4+IL-10+调节性T细胞及其细胞因子的改变。方法 用流氏细胞仪直接免疫荧光法检测AD患者外周血CD4+IL-10+T细胞的绝对计数和百分率;用酶联免疫吸附试验检测外周血细胞因子IL-10、TGF-β的浓度。 结果AD患者CD4+IL-10+T细胞绝对计数为0.26+0.126×109/L,占CD4+T细胞的百分率是12.76+4.85%;而对照组CD4+IL-10+T细胞绝对计数为0.016+0.007×109/L,占CD4+T细胞的百分率是3.27+1.03%。经t检验,AD患者CD4+IL-10+T细胞绝对计数和百分率均高于对照组,有统计学差异（p <0.05）。 AD患者外周血IL-10浓度为126.59+59.46 pg/ml,高于正常对照组（31.47+10.96 pg/ml）,经t检验,有统计学差异（p<0.05）。AD患者外周血TGF-β浓度为407.23+155.88 pg/ml,高于正常对照组（359.47+99.21 pg/ml）,但经t检验,没有统计学差异（p>0.05）。CD4+IL-10+T细胞绝对计数、百分率均与外周血IL-10浓度呈正相关,有统计学意义（r=0.47,r=0.65, p <0.05）;而与外周血TGF-β无统计学相关性（r=0.15,r=0.21 , p >0.05）。结论 IL-10可能是Trl发挥功能的主要因子,通过下调由Thl和Th2细胞介导的炎症反应过程,参与免疫调节。     

Differential effect of sodium arsenite during the activation of human CD4+ and CD8+ T lymphocytes

Contamination of water with arsenic is a problem affecting several regions of the world. Peripheral blood mononuclear cells (PBMC) from chronically exposed individuals show a lower replicating activity than non-exposed individuals when stimulated with phytohemagglutinin (PHA). We have previously reported that PBMC from healthy donors treated in vitro with 1 muM sodium arsenite (NaAsO2) and stimulated with PHA showed a reduction in proliferation by a delay in cell cycle entry and a decrease in the rounds of cell division. In this paper we tested the effect of 1-5 muM NaAsO2 on the proliferation, viability, blast transformation, expression of the CD4 and CD8 molecules, and during the activation and proliferation of both CD4+ and CD8+ T lymphocytes. We found a reduction in cell proliferation and an increase in non-dividing cells with higher concentrations of NaAsO2 (2-5 microM) when proliferation was studied by 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE) dilution. The use of 7-aminoactinomycin D (7-AAD) in CFSE-labeled cells allowed us to detect an increase in percentage of non-dividing cells, and an increase in apoptotic/dead cells mainly in non-proliferating cells. Analysis of the expression of CD4 and CD8 molecules on these cells showed that concentrations > or = 2 microM NaAsO2 reduced the expression of the CD8 molecule and induced apoptosis/death in CD4+ cells. Analysis of blast transformation by flow cytometry showed an accumulation of CD8+ resting cells in the presence of NaAsO2. Analysis of CD25 and CD69 expression in kinetics experiments in both subtypes showed a delay in the expression of CD25 and a delay in the downregulation of the CD69 molecule, in both CD4+ and CD8+ cells. However, in the case of CD8+ cells, we detected an accumulation of a CD25- CD69- population in the presence of increasing concentrations of NaAsO2. Altogether, our results show that NaAsO2 alters the expression kinetics of the early activation molecules CD25 and CD69 similarly in both subtypes. In addition, activated and non-activated CD4+ cells die by apoptotic mechanisms and although a percentage of CD8+ cells also die by apoptosis, a subpopulation of these cells is unable to activate and thus accumulates as resting cells.     

消癌平注射液联合化疗对中晚期肺癌患者CD4~+CD25~+FOXP3~+调节型T细胞的影响

目的探讨消癌平注射液联合化疗对中晚期肺癌患者CD4+CD25+FOXP3+调节型T细胞的影响。方法 71例Ⅲ～Ⅳ期非小细胞肺癌患者随机分为治疗组与对照组,治疗组36例采用化疗联合消癌平注射液;对照组35例单独采用化疗,两组化疗均采用GP方案。完成2周期后,通过流式细胞仪测定两组患者治疗前后外周血中CD4+CD25+FOXP3+调节型T细胞比例。结果治疗后治疗组患者CD4+FOXP3+T细胞占CD4+T细胞及CD4+CD25+T细胞的比例分别为(6.2±2.4)%和(27.6±6.0)%,而对照组分别为(8.2±0.5)%和(32.1±7.6)%,两组比较差异有统计学意义(P<0.05)。CD4+T细胞占总淋巴细胞的比例,治疗组较对照组明显提高(P<0.05)。结论消癌平注射液是一种较为理想的免疫增强剂,联合化疗可明显改善非小细胞肺癌患者的细胞免疫功能。     

Fluoxetine treatment to rats modifies serotonin transporter and cAMP in lymphocytes,CD4+ and CD8+ subpopulations and interleukins 2 and 4

Several lines of evidences indicate that antidepressants produce various immunomodulatory effects. Fluoxetine, an antidepressant and selective serotonin reuptake inhibitor, modulates immune cells in vitro. To explore the in vivo influence of fluoxetine on lymphocytes, male Sprague–Dawley rats were treated daily, 10 mg/kg, or with saline solution for 1, 2 and 3 weeks. The presence of serotonin transporter in CD3+, CD4+ and CD8+ subpopulations of T lymphocytes was determined by immunofluorescence. Serotonin transporter was also labeled with [³H]paroxetine, specific binding defined with imipramine. Plasma levels of pro-inflammatory interleukin 2 (IL-2), and anti-inflammatory interleukin 4 (IL-4), were measured by ELISA; and cAMP concentration by radioimmunoassay. Fluoxetine significantly increased the number of lymphocytes expressing serotonin transporter and elevated the binding of [³H]paroxetine. The percentage of CD4+ cells decreased, that of CD8+ increased, and CD3+ did not change. The ratio CD4+/CD8+ was significantly lowered. Fluoxetine administration elevated the levels of IL-4 at 1, 2 and 3 weeks; and of IL-2, at 2 and 3 weeks. IL-4/IL-2 ratio was significantly increased in fluoxetine group respecting the controls and was similar during the 3 weeks of treatment. Fluoxetine produced a significant decrease in cAMP concentrations in lymphocytes, probably by secondary activation of serotonin receptors. Treatment with fluoxetine modified immune parameters in plasma and lymphocytes of rats, which might be relevant for its systemic therapeutic action as an antidepressant.     

Kappa-opioid receptor agonist suppression of HIV-1 expression in CD4+ lymphocytes

Synthetic kappa-opioid receptor (KOR) agonists have been shown to suppress HIV-1 expression in acutely infected macrophages. In the present study, we examined the effects of the KOR ligand trans-3,4-dichloro-N-methyl-N[2-(1-pyrolidinyl)cyclohexyl]benzeneaceamide methanesulfonate (U50,488) on HIV-1 expression in CD4+ lymphocytes, the main target cell of this virus. When U50,488 was added to activated CD4+ lymphocytes, HIV-1 expression was inhibited in a concentration- and time-dependent manner with maximal suppression (approximately 60%) at 10(-7) M U50,488. The KOR selective antagonist nor-binaltorphimine (nor-BNI) had no effect by itself on viral expression but blocked the antiviral property of U50,488, suggesting that U50,488 was acting via a KOR-related mechanism. Support for the involvement of KOR was provided by the findings that 34% of activated CD4+ lymphocytes were positive for KOR, using an immunofluorescence technique, and that seven additional synthetic KOR ligands also inhibited HIV-1 expression. The results of this study broaden understanding of the antiviral properties of KOR ligands to include cells outside of the nervous system and suggest a potential role for these agents in the treatment of HIV-1 infection.     

急性白血病患者CD4+CD25+FoxP3+调节性T细胞、IL-17和IL-23的表达及临床意义

目的观察急性白血病(AL)患者外周血中CD4+CD25+FoxP3+调节性T细胞比例、血清白细胞介素(IL)17和IL-23的表达及其临床意义。方法用流式细胞术测定25例AL患者[急性髓系白血病(AML)15例,急性淋巴细胞白血病(ALL)10例]和10例健康体检者(对照组)外周血中CD4+CD25+FoxP3+调节性T细胞比例,ELISA法测定血清中IL-17和IL-23的表达,分析其间的相关性。结果 AML患者组CD4+CD25+FoxP3+调节性T细胞比例显著高于对照组[(6.52±3.25)vs.(3.58±1.02)](P<0.05);AML和ALL组血清IL-17水平显著高于对照组[(7.21±2.00),(7.47±1.63)vs.(4.52±1.62)](P<0.05)。AL患者血清IL-17和IL-23水平显著正相关(P<0.05)。结论 CD4+CD25+Foxp3+调节性T细胞和IL-17细胞在AML的免疫功能抑制中可能有重要作用,而IL-17细胞在ALL的免疫功能抑制中可能产生作用。     

Estradiol enhances capacity of TLR-matured splenic dendritic cells to polarize CD4+ lymphocytes into IL-17/GM-CSF-producing cells in vitro

There are little data on modulatory effects of estrogens on rat dendritic cell (DC) responses to inflammatory stimuli, and consequently their ability to activate and polarize CD4+ T lymphocyte-mediated immune responses. Splenic conventional DCs from young female Albino Oxford rats were activated in vitro with LPS (TLR4 agonist) or R848 (TLR7/8 agonist) in the presence and absence of 17β-estradiol (E2), and their allostimulatory and CD4+ lymphocyte polarizing ability in mixed leukocyte culture (MLC) were studied. Irrespective of the E2 presence, LPS and R848 up-regulated the expression of MHC II on DCs, so they exhibited enhanced allostimulatory capacity in co-culture with CD4+ lymphocytes. On the other hand, E2 promoted stimulatory action of both TLRs on OX62+ DC IL-23 production, augmented their stimulatory effects on IL-6 and IL-1β production, but diminished their enhancing effects on the expression IL-10 and IL-27 by DCs. Consequently, in MLC, OX62+ DCs activated/matured in the co-presence of E2 and either LPS or R848 increased the levels of IL-17, the signature Th17 cell cytokine, when compared with those activated/matured in the absence of E2. GM-CSF levels were also increased in these MLC. Given that the expression of IL-7 mRNA was diminished in DCs activated/matured in the co-presence of E2 and TLR, this increase most likely did not reflect enhanced differentiation of Th cells producing GM-CSF only (Th-GM).ConclusionsE2 augments capacity of LPS- and R848-activated/matured DCs from young rat spleen to induce differentiation of IL-17- and GM-CSF-producing cells.     

Modulation of collagen-induced arthritis by IL-4 and dexamethasone: the synergistic effect of IL-4 and dexamethasone on the resolution of CIA

We investigated effects of IL-4, dexamethasone (DXM), and the combination of IL-4 and DXM, low- or high-dose, on collagen-induced arthritis (CIA) in DBA/1 mice and correlated severity of arthritis with changes in IL-10 and IFN-gamma. Compared with control mice, mice treated with IL-4 had increased IL-10 with the same degree of arthritis, whereas mice treated with high-dose DXM had decreased IL-10 and increased IFN-gamma production with less severe arthritis. Mice treated with low-dose DXM showed the absence of IL-10 and increased IFN-gamma production with a trend toward the resolution of arthritis. Mice treated with IL-4 and low-dose DXM had neither IL-10 nor IFN-gamma production but revealed less severe arthritis, compared with mice treated with low-dose DXM alone. These results suggest that the beneficial effects of high-dose DXM and the combination of IL-4 and DXM on CIA are independent of IL-10 and IFN-gamma.     

登革热患者外周血CD4＋、CD8＋T细胞及IL-6的检测分析

目的 :观察登革热患者外周血CD4 、CD8 T细胞及IL—6的变化 ,探讨其在登革热疾病的发生和发展中的作用。方法 :12例健康人和18例登革热患者于治疗前后采静脉血 ,采用流式细胞仪检测CD4 、CD8 T细胞并计算CD4 /CD8 比值 ,ELISA检测血清IL—6水平 ,同时作外周血白细胞、血小板计数。结果 :与正常健康人和治疗后相比 ,登革热患者治疗前外周血CD4 细胞百分比、CD4 /CD8 比值明显降低 (P<0 01) ,CD8 细胞百分比和血清IL—6显著增高 (P<0 01) ,白细胞、血小板计数均明显下降 (P<0 01) ;治疗后患者以上指标与正常对照组比较差异无显著性。结论 :CD4 、CD8 T细胞在登革病毒感染后异常激活 ,CD4 /CD8 比值明显降低 ,IL—6分泌增高 ,可能在登革热的发病中起重要作用。     

Head and neck cancer triggers increased IL-6 production of CD34+ stem cells from human cord blood

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) are infiltrated by various kinds of immune cells, which show massively impaired immune functions. The influence of HNSCC on CD34 + progenitor cells from human cord blood was analyzed. MATERIALS AND METHODS: CD34+ cells were isolated from human cord blood by 'magnetic bead separation' using magnetically labelled antibodies. Immunofluorescent staining of CD34+ cells in solid HNSCC was carried out. Cytokine levels of IL-6, IL-8, and IL-10 were analyzed with flow cytometry using the BD CBA Human Soluble Protein Flex Set system (Becton Dickinson). RESULTS: We demonstrated that HNSCC triggered CD34+ cells to produce increased levels of the tumor-promoting cytokine IL-6 and thus they participate in the development of the microenvironment of head and neck cancer. CONCLUSION: HNSCC modulates the cytokine secretion profile of tumor infiltrating cells to escape from efficient immune responses und to trigger its own malignant progression.     

The C5a receptor antagonist PMX205 ameliorates experimentally induced colitis associated with increased IL-4 and IL-10

Background and Purpose

Anti-complement therapies have not been advanced for treating the inflammatory bowel diseases (IBDs) despite a growing body of evidence that blocking C5a protects against induced colitis in rodents. The purpose of this study was to further build on this evidence by examining the efficacy, mechanism and specificity of a potent, non-competitive and orally active C5a receptor (CD88) antagonist, PMX205, in the dextran sulphate sodium (DSS) model of murine innate colitis.

Experimental Approach

Mice with DSS added to their drinking water were orally administered 100 or 200 μg day⁻¹ PMX205 in prophylactic and therapeutic regimens. Clinical illness, colon histology and local generation of inflammatory mediators were measured to evaluate the impact of PMX205 on disease.

Key Results

PMX205 significantly prevented DSS-induced colon inflammation in both regimens, associated with lower pro-inflammatory cytokine production and nitrotyrosine staining in colon sections. Additionally, the levels of anti-inflammatory cytokines IL-4 and IL-10 were increased. PMX205 had no significant effect on C5a levels. The beneficial effect of PMX205 was seen in two strains of mice of differing sensitivities to DSS inflammation, but was inactive in mice lacking CD88.

Conclusions and Implications

Pharmacological inhibition of C5a activity by PMX205 is efficacious in preventing DSS-induced colitis, providing further evidence that targeting CD88 in IBD patients could be a valuable therapeutic option.     

Effects of IL-12 and IL-18 on HBcAg-specific cytokine production by CD4 T lymphocytes of children with chronic hepatitis B infection

The influence of IL-12 and IL-18 was evaluated on hepatitis B core antigen (HBcAg)-specific cytokine production (IFN-gamma, IL-4, IL-5 and IL-10) by CD4 T lymphocytes isolated from peripheral blood of children with chronic hepatitis B. CD4 T cells were isolated from peripheral blood of 20 children with chronic active hepatitis B, cultured for 48h in presence of rHBcAg and of co-stimulators, IL-12 or IL-18 or IL-12+IL-18 or in their absence (control). Production of studied cytokines was examined using the ELISPOT assay. Co-stimulation with IL-12 or IL-18 was found to significantly augment the HBcAg-specific secretion of IFN-gamma. However, the most pronounced stimulatory effect was observed in the presence of IL-12+IL-18 and resulted in peak levels of IFN-gamma production. The obtained results allowed concluding that the anti-HBV activity of Th1 lymphocytes is strongly induced by IL-12+IL-18 and may contribute to viral clearance in children with chronic hepatitis B infection.     

CD4+CD25+ regulatory T cells in health and disease

1. Over the past 5 years, tremendous progress has been made in understanding the suppressive mechanisms of T regulatory (Treg) cells. The Treg cells, a subpopulation of T cells, have been shown to play an important role in maintaining peripheral tolerance and the prevention of autoimmunity. 2. Various populations of Treg cells have been described, including thymically derived CD4(+)CD25(+) Treg cells. These naturally occurring Treg cells are present in the periphery and are capable of suppressing proliferation and effector T cell responses both in vitro and in vivo. 3. In addition, a second subset of Treg cells, type 1 T regulatoary (Tr1) and Th3 cells, exert their suppressive capacity via cytokines such as interleukin-10 and transforming growth factor-beta and are contact independent. 4. The present review summarizes the characteristics and molecular basis of CD4(+)CD25(+) Treg cells, as well as their therapeutic potential in modulating inflammatory diseases, such as inflammatory bowel disease and rheumatoid arthritis.     

Peripheral CD4+ CD25+ Treg cell expansion in lung transplant recipients is not affected by calcineurin inhibitors

CD4+CD25+ regulatory T (Treg) cells have been shown to play a role in allograft tolerance and their peripheral counts vary according to the degree of graft acceptance in lung transplant recipients (LTR). Recent studies demonstrate that certain drugs might modulate generation, expansion and activity of Treg cells. Aim of this study was to evaluate the effect of therapeutic regimens used in our institution on peripheral CD4+CD25(high)CD69- Treg cell numbers in a group of 51 LTR with stable clinical conditions. They were treated with standard immunosuppression: calcineurin inhibitor (CNI)+azathioprine (AZA)+steroids (n=28) or with CNI+mycophenolate mofetil (MMF)+steroids (n=11) or with CNI+steroids (n=12). These stable LTR were compared with age-matched healthy controls (n=35) and with 19 LTR who developed bronchiolitis obliterans syndrome (BOS) and were treated analogously. Stable LTR showed higher peripheral Treg cell counts with respect to age-matched healthy controls (59.9+/-31.8/mul versus 42.1+/-16.9/mul, respectively; p<0.05). This increase was detectable in all patients treated with CNI either in association with AZA or MMF. During these treatments a significant expansion of Treg cell counts was detectable during acute rejection (AR) episodes (86.03+/-26.6/mul during AR versus 36.34+/-7.6 before AR; p<0,05). Moreover, the development of BOS was associated to a significant decrease of Treg cell counts irrespective to the immunosuppressive regimen used. In conclusion, therapeutic regimens based on CNI seem to allow a certain degree of peripheral Treg cell expansion in stable LTR.     

Substance P increases and prolongs increased output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo: is it a mediator of immunological memory?

There are receptors on lymphocytes for substance P which are found both on small recirculating and on blast lymphocytes. The principal effect of substance P on lymphocytes appears to be a stimulating one, both in vitro and in vivo. The in vivo administration of substance P to sheep by acute infusion into cannulated afferent lymphatics of peripheral lymph nodes has been found to stimulate efferent lymph flow and the output into efferent lymph of both small recirculating and blast lymphocytes. We here report that substance P both enhances and prolongs the enhancement of the output of T4 (CD4) lymphocytes from lymph nodes of sheep in vivo. This output-stimulating effect appears to be specific to T4 (CD4) lymphocytes and is associated with a depressant effect on the output of T8 (CD8) and B lymphocytes. The output-stimulating effect on small T4 (CD4) lymphocytes is quite prolonged, lasting in excess of 96 h after a single 50 micrograms acute infusion. A brief post-infusion depression in T4 (CD4) lymphocyte output is associated with an equally brief, but marked, elevation in the output into efferent lymph of the arachidonic acid metabolite, thromboxane B2. The output-stimulating effect of substance P on blast T lymphocytes is confined to the T4 (CD4) blast lymphocytes. Substance P or a similar molecule may be of value when a specific T4 (CD4) lymphocyte output stimulant effect is desired. A single prior (6 days) acute infusion of substance P into a popliteal lymph node via its cannulated afferent lymphatic produced profound changes in the response to nodal drainage area immunization with killed S. muenchen bacteria. The latent period prior to increased antibody production was abolished, as was the standard post-immunization 'shutdown' period of decreased output of lymphocytes into efferent lymph. These changes were accompanied by a marked and progressive increase in antibody production. The findings reported here suggest substance P-induced long-term potentiation (LTP) of the immune response and raise the question of an involvement of substance P as a major mediator of immunological memory.     

The synthetic PPARgamma agonist troglitazone inhibits IL-5-induced CD69 upregulation and eosinophil-derived neurotoxin release from eosinophils

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear receptor that regulates lipid metabolism. Recently, PPARgamma was reported to be a negative regulator in the immune system. Eosinophils also express PPARgamma, however, the role of PPARgamma in eosinophil functions is not well understood. Surface expression of CD69 and eosinophil-derived neurotoxin (EDN) release are well-known activation markers of eosinophils. We investigated the effect of a PPARgamma agonist on human eosinophil functions such as IL-5-induced CD69 surface expression and EDN release. IL-5 significantly induced eosinophil CD69 surface expression analyzed using flow cytometry and EDN release measured by ELISA. IL-5-induced eosinophil CD69 surface expression and EDN release were significantly inhibited by the synthetic PPARgamma agonist troglitazone, and these effects were reversed by a PPARgamma antagonist. The PPARgamma agonist troglitazone has a potent inhibitory effect on activation and degranulation of eosinophils, and it may be a therapeutic modality for the treatment of allergic diseases.