LPS及IL-1ra对系膜细胞产生一氧化氮及增殖的影响

目的 :观察脂多糖 (LPS)对体外培养的系膜细胞 (GMC)产生NO的影响及这一过程对GMC增殖的影响。方法 :用培养的第一、二代SD大鼠肾小球系膜细胞进行实验 ,分别加入LPS或LPS加白细胞介素 - 1受体拮抗剂 (IL - 1ra) ,2 4h后用经典的Griess方法测定培养上清中亚硝酸盐含量 ,用 [3 H]-TdR掺入率测定GMC的增殖 ,狭缝和Northern杂交测定iNOSmRNA表达。结果 :LPS刺激后 ,GMC出现iNOSmRNA的表达及亚硝酸盐增多 [(0 6 4± 0 2 5 )nmmol/ 10 4 细胞vs (0 12± 0 0 6 )nmmol/ 10 4 细胞 ],GMC增殖 (3735± 1177 9vs 1785± 2 80 6 ) ;LPS加IL - 1ra组 ,iNOSmRNA表达比LPS组减少 40 % ,上清亚硝酸盐含量更高 [(3 2 8± 0 33)nmmol/ 10 4 细胞 ],GMC增殖被抑制 (818± 77 2 7)。结论 :LPS诱导GMCiNOSmRNA表达及亚硝酸盐增多 ,并有GMC增殖。IL - 1ra部分拮抗iNOSmRNA的表达 ,但亚硝酸盐产量更高 ,GMC增殖被抑制     

阿司匹林对炎症条件下人血管内皮细胞一氧化氮的产生及诱导型一氧化氮合酶mRNA表达的影响

目的:探讨炎症时阿司匹林(AS)对内皮细胞一氧化氮(NO)的产生及诱导型一氧化氮合酶(iNOS)基因表达的抑制作用。方法:Griess法测上清液NO^-₂/NO^-₃水平、黄递酶法测NOS活性、常规生化法测乳酸脱氢酶(LDH)、丙二醛(MDA)浓度,染料排除法测细胞活力,RT-PCR技术分析iNOSmRNA水平。结果:白介素(IL)-1β、肿瘤坏死因子(TNF)-α、γ-干扰素(INF)联用脂多糖(LPS)诱导后上清液中NO^-₂/NO^-₃由(4.27±0.75)μmol/L增加到(9.35±1.25)μmol/L,对内皮细胞造成明显的损伤。但3mmol/LAS组NO生成及NOS活性明显降低,LDH释放率及MDA浓度下降,细胞存活率上升,与NO诱导组相比差异显著。并随AS剂量的增加对NO的抑制及对细胞的保护作用更加明显,但AS对生理水平的NO没有抑制作用。同时发现10mmol/L浓度以下AS对iNOSmRNA表达水平没有影响;但10-20mmol/L的AS则可在转录水平上抑制iNOSmRNA的表达。并观察到水杨酸钠及消炎痛不具有抑制NO产生的作用。结论:AS具有明显抑制IL-1β、TNF-α、γ-INF及LPS诱导NO生成的作用,从而保护血管内皮细胞避免炎症时高浓度NO的损伤。     

正常人外周血TCRVα24+ NKT细胞体外活化特性观察

目的:探讨正常人外周血自然杀伤T(NKT)细胞的数量以及体外活化后表达CD69、IFN-γ和IL-4的规律并与CD3⁺ T细胞进行比较。方法:取正常成人外周血,直接三色荧光标记后溶血获取有核细胞,或以佛波醇酯(PDB)+离子霉素(Ion)刺激并培养6h,经三色荧光标记后溶血并获取有核细胞,以流式细胞术分析NKT细胞和T细胞的数量以及表达CD69和IL-4、IFN-γ的情况。结果:NKT细胞约占外周血T淋巴细胞总数的(1.34±0.42)%(x±s);PDB+Ion活化6h后NKT细胞CD69表达率为(96.71±1.33)%,明显高于对照组(11.47±2.86)%(P＜0.05);同样条件下CD3⁺T细胞CD69表达率分别为(98.60±0.47)%和(1.07±0.45)%(P＜0.05);当莫能菌素(monensin)存在时以PDB+Ion刺激6h后,IL-4阳性NKT细胞的百分比为48.62±2.44,明显高于对照组31.57±3.31(P＜0.05);IFN-γ阳性NKT细胞百分比为46.65±11.91,也高于对照组13.45±6.29(P＜0.01)。CD3⁺T细胞在刺激后表达IL-4和IFN-γ均明显升高,但IL-4表达率远远低于NKT细胞;而且对照组CD3⁺T细胞两种细胞因子表达率都明显低于NKT细胞。结论:正常成人外周血含有少量的NKT细胞,这些细胞IL-4和IFN-γ的表达率明显高于CD3⁺T细胞,是特定微环境里的重要免疫调节细胞。     

炎性细胞因子及脂多糖诱导产生的一氧化氮对人血管内皮细胞的损伤作用

目的:探讨炎症过程诱生的一氧化氮(NO)对内皮细胞的损伤及其作用机制。方法:黄递酶法及Griess法检测可诱导性NO合酶(iNOS)活性、NO₂^-/NO₃^-水平,RT-PCR技术分析iNOSmRNA的表达;同时观察NO产生后对内皮细胞的损伤作用。结果:IL-1β2×10⁵U/L、TNF-α5×10⁵U/L、γ-INF2×10⁵U/L联用LPS(10mg/L)可诱导出高浓度NOS合成及NO产生,比单用这些细胞因子或LPS诱导的量高两倍多,iNOSmRNA的表达水平也显著增加;同时MDA及LDH释放率明显增加,细胞存活率下降,并伴随细胞受损的形态学改变。而单用上述细胞因子或LPS,以及降低剂量或缩短处理时间,其诱生的NOS及NO与正常对照相比P＞0.05;但MDA及LDH释放率仍增加明显。使用2倍剂量的这些炎性细胞因子或延长处理时间到48h,与标准剂量及24h组相比NOS和NO的增加虽不显著,但细胞生长受限更明显。NOS抑制剂能阻止NO的产生及其对细胞的损伤作用。结论:炎性细胞因子及脂多糖可激活iNOS大量表达诱生高浓度的NO,对内皮细胞具有明显的氧化损伤作用。     

蛋白激酶C抑制剂对T细胞表达IL-2及IFN-γ的影响

目的:研究蛋白激酶C(PKC)抑制剂H7和棉酚对体外活化T细胞表达白细胞介素-2(IL-2)和γ-干扰素(INF-γ)的影响。方法:在莫能菌素(monensin)存在时,以佛波醇酯(PDB)+离子霉素(I)体外活化人外周血单个核细胞(PBMC),以流式细胞术胞内细胞因子检测法分析H7和棉酚对CD3⁺T细胞表达IL-2和IFN-γ水平的影响。结果:PDB+I处理PBMC4h后,表达IL-2和IFN-γ的CD3⁺T细胞百分率分别为16.64±2.04和25.81±3.53(x±s),而对照组二者的比率为1.06±0.22及3.12±0.77(P＜0.05)。棉酚(50μmol/L)可明显抑制IL-2及IFN-γ的表达,抑制后表达率分别为2.08±0.12及9.01±1.90。H7作用比棉酚强,50μmol/L的H7抑制后的IL-2及IFN-γ阳性T细胞比率分别为0.43±0.06和2.40±0.27。结论:PKC在CD3⁺T细胞表达IL-2及IFN-γ中发挥重要作用;PKC抑制剂H7及棉酚明显抑制IL-2及IFN-γ的表达,提示H7和棉酚可通过抑制PKC活性,对依赖于T细胞功能的特异性免疫应答有调节作用。     

LPS急性肺损伤大鼠肺巨噬细胞TL R4与IL-18 mRNA表达的变化

目的: 观察LPS急性肺损伤(ALI)大鼠肺巨噬细胞Toll样受体4(Toll-like receptor 4, TLR4)及IL-18mRNA表达的变化,探讨TLR4与IL-18在ALI中的作用。方法: 运用RT-PCR与ELISA检测TLR4和IL-18 mRNA的表达及肺巨噬细胞培养液上清TNF-α浓度。结果: LPS急性肺损伤组TLR4与IL-18 mRNA表达显著高于正常对照组(0.43±0.07 vs 0.25±0.03, 0.38±0.02 vs 0.16±0.03), TNF-α分泌显著多于正常对照组(0.74±0.02 vs 0.41±0.02)。结论:LPS急性肺损伤时肺巨噬细胞TLR4功能及其介导的信号转导作用加强, IL-18分泌增加, 表明二者在急性肺损伤中起重要作用。     

四氯化碳性脂肪肝血清游离脂肪酸谱变化

目的:探讨CCl₄性脂肪肝血清游离脂肪酸谱的变化。方法:以40%CCl₄腹部皮下注射的方法复制CCl₄性脂肪肝大鼠模型。用气相色谱方法测定血清游离脂肪酸谱。结果:CCl₄性脂肪肝模型组血清游离脂肪酸谱中多不饱和脂肪酸水平明显低于对照组[油酸C18:1,(28.672±7.332/mg.L^-1vs41.373±2.180/mg.L^-1),亚油酸C18:2(16.739±0.871/mg.L^-1vs24.959±5.325/mg.L^-1),花生四烯酸C20:4(6.105±2.656/mg.L^-1vs9.802±0.779/mg.L^-1),P<005],而饱和脂肪酸的水平则显著高于对照组[月桂酸C12：0(3.368±0.330/mg.L^-1vs2.7420.351/mg.L^-1),肉豆蔻酸C14:0(27.1363.158/mg.L^-1vs16.152±0.638/mg.L^-1),棕榈酸C16:0(51.731±9.561/mg.L^-1vs34.522±1.401/mg.L^-1),P<005]。结论:CCl₄性脂肪肝血清中不饱和脂肪酸水平明显降低,饱和脂肪酸水平显著升高。     

2型糖尿病患者CD14CD16单核细胞的水平及其对LPS和IL-15刺激的反应

目的: 研究2型糖尿病(T2DM)患者外周血CD14⁺CD16⁺单核细胞的比例及脂多糖(LPS)联合白细胞介素 15(IL-15)对其的影响,以了解炎症性免疫反应在T2DM中的可能作用机制。方法: 对28例T2DM患者和20例健康志愿者外周血用流式细胞术检测CD14⁺CD16⁺单核细胞的比例,并分离其外周血单个核细胞(PBMC),用LPS和IL-15干预4 h,收集PBMC和培养上清。分别采用Western blotting检测PBMC内STAT5和p-STAT5蛋白表达。免疫荧光检测p-STAT5蛋白表达,ELISA法检测外周血25-羟维生素D₃ 和IL-6浓度,免疫比浊法检测其外周血C-反应蛋白(CRP)水平, ELISA法检测LPS和IL-15干预后细胞培养上清IL-6和单核细胞趋化蛋白-1(MCP-1)的浓度。结果: T2DM组外周血CD14⁺CD16⁺单核细胞数量明显高于正常对照组(P<0.01),并与血清CRP和IL-6水平呈正相关(r=0.394,P<0.05和r=0.741,P<0.01),与25(OH)D₃浓度呈负相关(r=0.409,P<0.01),且25(OH)D₃水平与CRP和IL-6水平均呈负相关(r=-0.479和r=-0.774,均P<0.01),LPS联合IL-15刺激后PBMC的p-STAT5蛋白表达水平和PBMC培养上清IL-6、MCP-1浓度明显高于正常对照组(P<0.01),且T2DM患者p-STAT5的表达存在激活现象。结论: T2DM患者体内存在单核细胞功能紊乱,这种功能紊乱可能与活性维生素D₃不足有关,二者可能参与了T2DM患者体内免疫炎症反应并与微炎症互为因果,从而导致了T2DM及其并发症的发生发展;其作用机制可能与STAT5信号通路的激活有关。     

脂多糖活化星形胶质细胞并下调其内向整流性钾离子通道(Kir4.1)的表达

目的探讨脂多糖(LPS)对星形胶质细胞的活化作用及内向整流性钾离子通道4.1(Kir4.1)表达的影响。方法分离培养新生SD大鼠大脑皮层星形胶质细胞;LPS处理或者和白细胞介素1受体拮抗剂(IL-1ra)处理培养的细胞,MTT法检测细胞活力,免疫细胞化学技术检测星形细胞胶质纤维酸性蛋白(GFAP)的表达,ELISA检测细胞培养上清中的IL-1β的水平,实时定量PCR法检测星形胶质细胞IL-1β和Kir4.1 mRNA的表达情况。结果 LPS促进星形胶质细胞的活化具有浓度和时间依赖性。LPS可促进星形胶质细胞IL-1β的分泌和IL-1βmRNA的表达,下调Kir4.1 mRNA的表达;与LPS组相比较,IL-1ra可以有效对抗上述两结果。结论 LPS可诱导培养的星形胶质细胞活化;LPS下调星形胶质细胞Kir4.1 mRNA表达可能与IL-1β有关。     

人外周血CD8+T细胞CD28、CD56及CD57表达水平的老年性改变

目的:通过对健康老年人与青年人外周血CD8⁺T细胞CD28、CD56及CD57表达水平的比较性研究,探讨免疫衰老的细胞学机制。方法:采用三色免疫荧光标记流式细胞术分析青年组(20-35岁)与老年组(60-75岁)外周血CD8⁺CD28⁺、CD8⁺CD56⁺及CD8⁺CD57⁺T细胞水平。结果:老年组外周血CD8⁺CD28⁺T细胞明显低于青年组,阳性百分率分别为34.07±5.29和49.84±7.43(P＜0.05);而老年组CD8⁺CD56⁺T细胞及CD8⁺CD57⁺T细胞均明显高于青年组,前者阳性百分率分别为6.60±2.40和2.10±0.35,后者阳性百分率分别为41.82±6.01和22.89±2.80(P＜0.05)。结论:老年人CD8⁺T细胞CD28、CD56及CD57的表达率均随年龄增长有明显改变;CD28表达下降可能是引起免疫系统功能降低的重要原因,而CD56、CD57表达水平的增加则可能是机体对细胞免疫功能下降的一种代偿性适应。     

白细胞介素13抑制肾小球系膜细胞增殖及白细胞介素6表达

目的:探讨白细胞介素13(IL-13)对体外培养的大鼠系膜细胞的增殖及其产生白细胞介素6(IL-6)的影响。方法:用四甲基偶氮唑(MTT)法测定系膜细胞增殖,用逆转录聚合酶链反应(RT-PCR)及酶联免疫吸附法(ELISA)测定系膜细胞IL-6mRNA表达及其蛋白水平。结果:IL-13在1、10、100μg/L浓度范围呈剂量依赖性地抑制系膜细胞的增殖;5%FCSRPMI1640培养条件下系膜细胞IL-6mRNA表达及IL-6分泌水平较低,脂多糖(LPS)可刺激系膜细胞IL-6mRNA的表达及提高IL-6分泌水平,而IL-13可抑制LPS诱导的系膜细胞IL-6分泌及其mRNA表达。结论:IL-13抑制体外培养的系膜细胞增殖及LPS诱导的系膜细胞IL-6的产生,IL-13可能对于肾小球肾炎的系膜细胞炎症反应具有拮抗作用。     

Role of interleukin-1 in mesangial cell proliferation and matrix deposition in experimental mesangioproliferative nephritis.

We examined the functional role of interleukin (IL)-1 in mesangial cell proliferation during rat anti-Thy-1 nephritis by blocking its action with IL-1 receptor antagonist (IL-1ra). Anti-Thy-1 nephritis was induced by intravenous injection of 5 mg/kg OX-7 IgG (day 0) into inbred Wistar rats. Groups of animals (n = 9) were implanted with a micro-osmotic pump on day -1, which delivered 25 micrograms/hour human recombinant IL-1ra or saline continuously until the rats were killed at day 6, the peak of mesangial cell proliferation. Immunostaining showed that IL-1 was expressed by mesangial cells during disease. IL-1ra treatment did not affect the mild, but significant, proteinuria seen after OX-7 injection. Compared with saline treatment, IL-1ra treatment reduced mesangial cell proliferation (decreases 24% P < 0.05), glomerular hypercellularity (decreases 29%; P < 0.05), and glomerular macrophage accumulation (decreases 20%; P < 0.05). However, IL-1ra treatment had no effect on glomerular IL-1 beta mRNA expression and caused only a small reduction in the high levels of glomerular expression of platelet-derived growth factor-beta protein (decreases 6%; P < 0.05). IL-1ra caused a modest reduction in the marked up-regulation of glomerular transforming growth factor-beta 1 mRNA expression on day 6 (decreases 26%; P < 0.05), although urinary excretion of this factor was unaffected. Interestingly, IL-1ra treatment had relatively little effect upon glomerular deposition of laminin, fibronectin, and collagen type IV seen in this acute disease. In conclusion, this study has 1) demonstrated that IL-1 is expressed by mesangial cells in vivo, 2) demonstrated that IL-1 is a mesangial cell growth factor in experimental mesangioproliferative nephritis, and 3) suggests that IL-1 has little or no fibrogenic activity in mesangial matrix deposition.     

几种中药有效成分对大鼠系膜细胞IL-6 mRNA表达的影响

目的与方法:体外培养大鼠系膜细胞,以脂多糖(lipopolysaccharide, LPS)刺激后,分别加入补肾活血泄浊汤有效成分川芎嗪、大黄素、灵芝多糖,应用Northern杂交技术,观察上述几种中药有效成分对系膜细胞IL-6基因表达的影响,以探讨补肾活血泄浊汤治疗肾小球肾炎的机制。结果:川芎嗪、大黄素、灵芝多糖均可抑制IL-6基因的表达,以大黄素最为显著。结论: 结果提示补肾活血泄浊汤可能通过抑制IL-6基因的表达,从而减轻系膜细胞增生。     

Interleukin-6 and Interleukin-6 Receptor are Expressed by Cultured Glomerular Epithelial Cells

Interleukin-6 (IL-6) has been extensively studied in mesangial cells but little is known about the expression of this cytokine and its receptor in glomerular epithelial cells (GEC). IL-6 was detected in the culture supernatants of human GEC and its production was enhanced in time and dose dependent manner by lipopolysaccharide (LPS), interleukin-1β (IL-Iβ) and tumour necrosis alpha (TNF-α). Quiescent, serum-starved GEC did not express clearly IL-6 mRNA. Stimulation of cells with LPS, TNF-α or IL-1β resulted in an increase of detectable IL-6 mRNA. Interestingly, it was found that IL-6 induced its own mRNA attesting that this cytokine was secreted in autocrine fashion by GEC. GEC expressed IL-6 receptor (IL-6R) as demonstrated directly by the existence of IL-6R mRNA detected by northern blotting. Stimulation of GEC by pro-inflammatory mediators such as LPS increased the expression of IL-6R mRNA. The soluble form of IL-6 receptor (sIL-6R) was not detectable in the culture supernatants harvested from untreated or cytokine-treated cells. We investigated further, whether IL-6 may influence growth of cultured GEC. Incubation of GEC with recombinant (r) IL-6 resulted in a dose dependent increase in ³H thymidine incorporation indicating that IL-6 acts as an autocrine growth factor for GEC. We conclude that GEC are a potent source of IL-6, the local excessive expression of IL-6 and its receptor may play a substantive role in the regulation of processes which appear critical to the initiation of progressive glomerular disease such as cell proliferation.     

Benznidazole, a drug employed in the treatment of Chagas' disease, down-regulates the synthesis of nitrite and cytokines by murine stimulated macrophages.

Benznidazole (BZL) is a nitroheterocyclic drug employed in the chemotherapy of Chagas' disease, a protozoan disease caused by Trypanosoma cruzi. Because this parasite mostly replicates in macrophages, we investigated whether BZL was likely to modify the synthesis of macrophage mediators such as nitrite, tumour necrosis factor-alpha (TNF-alpha), IL-1beta, IL-6 and IL-10. Control and stimulated murine macrophages (lipopolysaccharide (LPS) and/or interferon-gamma (IFN-gamma)) were treated with BZL and measurements were carried out in culture supernatants collected 24 h later. Synthesis of nitrite, IL-6 and IL-10 was maximal upon combined stimulation with LPS + IFN-gamma, whereas lower amounts of the three mediators were detected when both stimuli were given alone. BZL treatment significantly reduced nitrite, IL-6 and IL-10 production, to undetectable levels in some cases, particularly IL-6 and IL-10. LPS was the most potent stimulus of IL-1beta and TNF-alpha production, followed by LPS + IFN-gamma and IFN-gamma in decreasing order. BZL partly inhibited TNF-alpha synthesis, but this effect was smaller than that observed for nitrite, IL-6 and IL-10. LPS-induced production of IL-1beta was also affected by BZL. Semiquantification of gene expression for inducible nitric oxide synthase (iNOS) showed that BZL completely inhibited iNOS gene induction by IFN-gamma, and resulted in respective inhibitions of 30% and 50% with LPS- and LPS + IFN-gamma-stimulated cells. BZL was not cytotoxic on macrophage cultures, as shown by the lactate dehydrogenase activity. Besides its trypanocidal activity, BZL may also alter the balance between pro- and anti-inflammatory mediators with important consequences for the course of T. cruzi infection.     

IL-13对LPS诱导人系膜细胞分泌IL-12的影响

目的: 探讨白细胞介素13（IL-13）对肾小球系膜细胞分泌白细胞介素12（IL-12）的影响作用。方法: 用酶联免疫吸附（ELISA）法和逆转录聚合酶链反应（RT-PCR）法检测系膜细胞IL-12蛋白和L-12p40 mRNA表达。结果: LPS诱导系膜细胞的IL-12p40 mRNA表达及其蛋白分泌（P<0.01）。IL-13在1-100 μg/L浓度范围内呈剂量依赖性抑制LPS诱导的系膜细胞IL-12分泌及其mRNA表达（P<0.05或P<0.01）。结论: IL-13可能通过抑制LPS诱导系膜细胞分泌IL-12，而调整了体内Th1/Th2细胞因子平衡。     

丝裂原激活蛋白激酶在内毒素脂多糖诱导大鼠施万细胞一氧化氮合酶表达中的作用

目的 主要研究丝裂原激活蛋白激酶(MAPK)信号途径在内毒素脂多糖(LPS)诱导大鼠施万细胞(Scs)诱导型一氧化氮合酶(iNOS)基因表达和一氧化氮(NO)产生中的作用.方法 先用3种MAPK的特异性抑制剂PD98059(ERK1/2)、SB202190(P38 MAPK)和SP600125(JNK)以不同浓度预处理细胞1h,再用LPS作用施万细胞4 h后,用RT-PCR检测细胞中iNOS mRNA、IL-6 mRNA和TNF-α mRNA的表达;Western blotting观察iNOS蛋白水平的表达变化;通过测定细胞培养液中亚硝酸盐含量来观察NO的水平.结果 LPS可显著激活施万细胞中MAPK信号通路诱导iNOS表达.MAPK的抑制剂预处理细胞后,可显著抑制细胞iNOS mRNA和NO的合成及IL-6 mRNA和TNF-α mRNA的表达.结论 MAPK信号通路参与了LPS介导的大鼠施万细胞iNOS基因表达和NO产生,通过阻断细胞内信号转导通路来减少iNOS及其他细胞因子的产生,为抑制周围神经损伤后的炎症以及免疫反应发生提供了一条新思路.     

α7nAChR参与生理浓度糖皮质激素的抗炎作用*

 目的： 探讨α7烟碱型乙酰胆碱受体（α7nAChR）在生理浓度糖皮质激素（GCs）抗炎过程中的作用。方法: MTT法检测不同浓度氢化可的松对小胶质细胞BV-2活性的影响;在建立LPS刺激的BV-2细胞炎症模型基础上,实验分组如下：(1) 空白对照组;(2) LPS组;(3) GCs＋LPS组;(4) α7nAChR阻断剂甲基牛扁亭碱（MLA）＋GCs＋LPS组,ELISA法测定细胞上清中TNF-α和IL-1β的含量。结果: 2 000 和1 000 nmol/L 氢化可的松可分别使细胞存活率降低至(76.9±5.5)%和(90.8±7.3)%,表现出超生理剂量GCs的细胞损伤作用。LPS明显刺激BV-2细胞释放TNF-α和IL-1β,并呈现时间和剂量依赖性。生理浓度（500和250 nmol/L）的氢化可的松均可减少LPS诱导BV-2细胞释放TNF-α和IL-1β,10 nmol/L MLA预处理BV-2细胞能拮抗GCs抑制炎症因子释放的作用。结论: α7nAChR参与了生理浓度GCs的抗炎作用。     

Interferon-gamma stimulates the secretion of IL-1, but not of IL-6, by glomerular mesangial cells.

IL-1 activity in culture supernatant and cell lysate from rat mesangial cells stimulated with interferon-gamma (IFN-gamma) was measured by a thymocyte proliferation assay. While IFN-gamma alone had no effect on the secretion or the intracellular pool of IL-1, the enhancement by IFN-gamma of IL-1 secretion in response to lipopolysaccharide (LPS) was observed. The stimulatory effect of culture supernatant on thymocyte proliferation was abrogated by preincubation with the anti-IL-1 antibody. At least 4-h incubation with IFN-gamma and LPS was required to detect enhancing effect of IFN-gamma. The addition of as little as 1 U/ml IFN-gamma significantly increased IL-1 secretion in the presence of 10 micrograms/ml LPS. The IL-6 activity in culture supernatants was determined by measurement of thymidine uptake in mouse IL-6-dependent cell line (MH60.BSF2). Mesangial cells secreted IL-6 in culture supernatant without additional stimuli and LPS distinctly increased it as described previously. However, in contrast to IL-1 production, no effect of IFN-gamma on IL-6 secretion was observed in the presence or absence of LPS. Moreover, we determined whether enhanced IL-1 release is associated with Ia expression on mesangial cells. IFN-gamma alone and the combination with LPS induced marked expression of Ia antigen, whereas LPS alone did not. We conclude that IFN-gamma stimulates the production of IL-1, but not IL-6, by mesangial cells and suggest an important role of IFN-gamma in the pathogenesis of glomerulonephritis by regulating the mesangial production of IL-1 and the accessory cell function of mesangial cells.