Inhibition of IL-12 synthesis of peripheral blood mononuclear cells (PBMC) stimulated with a bacterial superantigen by pooled human immunoglobulin: implications for its effect on Kawasaki disease (KD)

The aim of this study was to further assess the role of pooled human immunoglobulin (PHIG) on cytokine production from PBMC stimulated with a bacterial superantigen. Human PBMC were cultured with Streptococcus pyrogenic exotoxin A (SPE-A) with or without PHIG and several proinflammatory cytokine levels of culture supernatants were measured. Serum cytokine levels of KD patients before and after PHIG therapy were also examined. PHIG greatly reduced the production of IL-12, interferon-gamma (IFN-γ) and other cytokines from SPE-A-stimulated PBMC, while exogenous IL-12, but neither IL-1 nor tumour necrosis factor-alpha (TNF-α), restored IFN-γ production inhibited by PHIG. Although PHIG partially adsorbed SPE-A, its inhibitory effect on cytokine production was not played by anti-SPE-A antibody. Although purified CD4⁺ T cells cultured with human HLA-DR-transfected mouse L cells and SPE-A could not effectively produce IFN-γ, they produced large amounts of IFN-γ if exogenous IL-12 was introduced. KD patients in the acute phase had higher levels of serum IFN-γ than did controls and patients with bacterial infection. Although IL-12 levels of children with or without KD were not significantly different, IL-12 levels of children were much higher than those of adults. However, serum levels of IL-12 of KD patients were transiently but significantly decreased by PHIG therapy and IFN-γ amounts subsequently reverted to basal levels thereafter. These findings indicate that PHIG inhibits IL-12 production of SPE-A-activated monocytes and thereby decreases IFN-γ synthesis by T cells and suggest that inhibition of IL-12 and IFN-γ production is an important part of the mechanisms underlying PHIG therapy on KD.     

Failure of P strain mice to respond to vaccination against schistosomiasis correlates with impaired production of IL-12 and up-regulation of Th2 cytokines that inhibit macrophage activation

In contrast to most inbred strains, P mice fail to develop significant resistance to Schistosoma mansoni infection as a result of vaccination with either radiation-attenuated cercariae or schistosome antigens plus Bacillus Calmette Guérin, and this failure correlates with defects in macrophage larvicidal activity. Supernatant fluids from antigen-treated in vitro cultures of splenocytes from vaccinated P mice demonstrate less macrophage stimulatory activity than do supernatants from cells of vaccine-responsive strains such as C57BL/6. This is not due either to diminished production of the macrophage-activating cytokine IFN-γ by P mice, or to a lesser responsiveness of macrophages from P mice to activation by IFN-γ. Rather, P splenocytes produce two-to threefold higher amounts of IL-4 and IL-10, cytokines which down-regulate the cytotoxic potential of IFN-γ-treated macrophages. Thus, the macrophage-activating potential of cytokine preparations from vaccinated P mice can be completely recovered by in vitro treatment with antibodies to IL-4 or IL-10. Moreover, lower levels of IL-12, a cytokine involved in promoting development of Th1 responses, are produced by splenocytes from P mice as compared to C57BL/6 counterparts. These studies indicate that a genetic predisposition toward an impaired production of IL-12 and an increased production of down-regulatory Th2 cytokines correlate with low response to vaccination against S. mansoni.     

Th1 and Th2 Cytokine Modulation by IL-10/IL-12 Imbalance in Autoimmune Haemolytic Anaemia (AIHA)

Recent studies about autoimmune diseases in animal models and in humans focused their attention on lymphocyte activation and in vitro cytokine production. The respective contribution of the Th1 and Th2 cytokines to the pathogenesis of autoimmune diseases is still a matter of debate. In this study the role of IL-2, IL-4, IFN- &#110, IL-10 and IL-12 cytokines were investigated by examining their spontaneous and mitogen-induced (OKT3 and PHA or LPS) synthesis and T-cells proliferative response by peripheral blood mononuclear cells to determine their role in the pathogenesis of AIHA. Thirteen patients affected by AIHA, idiopathic or associated with other diseases, and 13 healthy subjects, randomly selected from a group of blood donors, were investigated. This study indicated that AIHA is characterised by increased basal synthesis of IL-4 and decreased levels of IFN- &#110 compared with healthy controls ( p <0,01). These results suggest that there is a basal decrease of Th1 cytokine and an increase of the Th2 ones. Enhanced IL-2 levels in AIHA patients are likely due to the necessity of a T-cell proliferation stimulus rather than produced as Th1 prevalent stimulation. Furthermore, it has been observed a significant increase in IL-12 production in LPS stimulated cultures from healthy controls, but not in AIHA patients, that shows IL-10 increased levels, which could cause a secondary decrease in IFN- &#110 production and a stimulation of Th2 differentiation. These observations indicate that decreased production of Th1-type cytokines and prevalent Th2 ones leading to autoantibodies production in AIHA may be secondary to the imbalance between IL-10 and IL-12. These results strongly suggest that manipulation of the cytokine network, i.e. IL-10/IL-12 balance, maintained by cells of the innate immune system, can have a strong effect on the incidence of AIHA and their modulation might be useful for a therapeutic control of the disorder.     

呼吸道合胞病毒毛细支气管炎患儿IL4/IFNγ水平变化及意义

为研究Th1/Th2类细胞因子 (CK )在呼吸道合胞病毒毛细支气管炎 (RSV毛支 )发病中的作用 ,本文采用酶联免疫吸附试验 ,对 2 0例RSV毛支患儿和 15例健康婴幼儿外周血单个核细胞 (PBMC )经植物血凝素 (PHA )刺激培养后 ,测定上清液中某些细胞因子 ,并同时检测患儿血浆总IgE水平。实验结果表明 :(1)经PHA刺激培养后 ,RSV毛支组上清液中IL 4,IFN γ水平及IL 4/IFN γ比值与对照组比较 ,差异有显著性 (P <0 0 1、 0 0 5、 0 0 1)。RSV毛支组血浆总IgE水平较对照组明显升高 (P <0 0 1) ;(2 )相关分析 :培养上清液中IL 4水平 ,IL 4/IFN γ比值与血浆总IgE水平间呈显著正相关 ,IFN γ与IgE间呈显著负相关。此外IL 4与IFN γ间呈显著负相关。结果提示 ,RSV毛支患儿存在Th1/Th2功能紊乱 ,主要表现为Th2细胞功能亢进 ;IL 4、IFN γ参与了RSV感染时的免疫病理机制。     

IL-13和IL-4在哮喘发病中的作用及相互关系

目的　探讨IL 13在哮喘发病中的作用及其与IL 4的相互关系。方法　哮喘组 2 4例 ,男 17例 ,女 7例 ;健康对照组 2 4例 ,男 12例 ,女 12例。用ELISA法检测不同时段PBMC培养上清IL 13和IL 4水平及加IL 13单克隆抗体 (McAb)和IL 4McAb干预后PBMC培养上清IL 4、IL 12、IL 13和IFN γ水平。结果　 (1)IL 13动态变化 :①对照组PBMC培养 3d、5d、7d水平均较培养 1d水平高 ,差异有显著性 ,培养 3d的水平较培养 5d、7d的高 ,差异有显著性 ;②哮喘组PBMC培养 3d、5d、7d的水平均较培养 1d的水平高 ,差异有显著性 ,培养 5d的水平均较培养 3d、7d的水平高 ,但之间差异无显著性 ;③哮喘组PBMC培养 3d、5d、7d的IL 13水平均较对照组高 ,差异有显著性。 (2 )IL 4动态变化 :①对照组和哮喘组PBMC培养 1d后 ,IL 4水平明显上升 ,第 3天仍保持较高水平 ,第 5、7天明显下降 ;②哮喘组 1d、3d、5d和 7d水平均较对照组高 ,差异有显著性。 (3)IL 4McAb干预后 ,哮喘组和正常组IL 13水平与对应小鼠IgG组相比有显著性降低 ,哮喘组IFN γ水平与对应小鼠IgG组相比有显著性增高。 (4)IL 13McAb干预后IL 12水平在哮喘组和正常组均提高 ,与对应小鼠IgG组相比差异有显著性。 (5 )IL 13McAb和IL 4McAb联合干预后哮喘组I     

SLE患者IFN-γ、IL-4及IL-12水平变化及意义

从Th1/Th2细胞代表性细胞因子IFN γ/IL 4和IL 12水平的变化分析SLE患者Th1/Th2细胞的偏移现象。本实验通过半定量PCR法和ELISA酶联免疫检测法检测上述三种细胞因子含量。实验结果显示 ,SLE患者IL 4/IFN γ基因水平比值为0 32 8,高于对照组 (0 0 7)。ELISA检测显示IL 12在SLE患者血清中为 (38 39± 15 1)pg/ml,低于对照组 (84 97± 13 7)pg/ml(P <0 0 5 )。结论 :SLE患者Th1/Th2细胞因子平衡失调 ,IL 4细胞因子基因水平增高 ,同时血清中IL 12水平降低。     

Immuno-regulatory cytokines in asthma: IL-15 and IL-13 in induced sputum

BACKGROUND: The importance of Th2-type lymphocyte function in asthmatic airway inflammation is well recognized, but less is known about the factors which regulate the function of these lymphocytes in asthma. The macrophage-derived cytokine, interleukin (IL)-15 has a number of T cell regulatory properties which might be of relevance to asthma and its treatment. OBJECTIVE: The aims were to identify and quantify the T cell regulatory cytokine IL-15 in induced sputum samples from asthmatic patients, in comparison with IL-13, and to relate the levels of these cytokines to treatment with inhaled steroids. METHODS: Induced sputum was collected from 16 asthmatics (eight steroid and eight non-steroid treated) and eight normal controls. IL-15 and IL-13 levels were measured by enzyme-linked immunoassay (ELISA) in sputum. IL-15 levels were also measured in sputum cell culture supernatants and localized to specific sputum cells by immuno-cytochemistry. RESULTS: IL-15 levels were increased and IL-13 levels were decreased in sputum fluid from steroid-treated compared with non-steroid-treated asthmatics. IL-15 was localized specifically to macrophages and the proportion of these cells expressing IL-15 correlated with sputum fluid IL-15 and IL-15 levels in cell culture supernatants, and all were higher in the steroid-treated asthmatics. CONCLUSION: IL-15 and IL-13 production appears to be reciprocally regulated by steroid therapy in asthma patients. The steroid-associated increase in IL-15 may regulate a fundamental shift away from an inflammatory Th2-type environment in asthma and may be an essential component of the cytokine modulation underlying the therapeutic benefit of corticosteroids in this condition.     

Sequential production of cytokines by dengue virus-infected human peripheral blood leukocyte cultures.

The study was undertaken to elucidate the sequence of appearance of T helper (Th)1- and Th2-type cytokines in human peripheral blood leucocyte cultures infected in vitro with dengue type 2 virus. Commercial sandwich enzyme-linked immunosorbent assay kits were used to assay the levels of tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), interleukin (IL)-2, IL-4, IL-5, IL-6, and IL-10 in culture supernatants. Culture supernatants were also screened for the cytotoxic factor and the dengue virus titres determined. The cytokines that appeared in the culture supernatants on the first day post-infection (p.i.) were cytotoxic factor, TNF-alpha, IL-2, and IL-6; their levels were highest on the second day p.i. IFN-gamma appeared on the second day with a peak on the third day p.i. The levels of these cytokines declined quickly, except for human cytotoxic factor (hCF) and IL-2. The cytokines that appeared later were IL-10 and IL-5 on the fourth day and IL-4 on the sixth day p.i. Dengue virus replicated in the peripheral blood leucocyte (PBL) cultures and was present throughout the course of the study. The findings of the present study show that dengue virus induced a predominant Th1-type cytokine response during the first 3 days of infection of PBL cultures that was replaced by a Th2-type response later.     

Enhanced prostaglandin E2 production by monocytes in atopic dermatitis (AD) is not accompanied by enhanced production of IL-6, IL-10 or IL-12

AD is associated with a bias of the T helper cells to show increased IL-4 and reduced interferon-gamma (IFN-γ) production. The production of IFN-γ and IL-4 and the development of Th cells into either high IFN-γ or high IL-4 producers is strongly influenced by factors produced by antigen-presenting cells (APC), like IL-12 and prostaglandin E₂ (PGE₂). IL-12 selectively enhances IFN-γ production and favours the development of IFN-γ-producing Th cells, whereas PGE₂ selectively inhibits IFN-γ production by Th cells. The aim of this study was to test whether the increased IL-4/IFN-γ production ratio by Th cells in AD can be explained by an increased PGE₂/IL-12 production ratio by the APC. Monocytes were used as APC source. PGE₂ and IL-12 production by lipopolysaccharide (LPS)-stimulated monocytes from 12 AD patients and 12 non-atopic controls was determined using two complementary experimental systems, whole blood cultures and purified monocytes. In addition, we determined IL-6 production as a measure of monocyte activation, and IL-10 production because IL-12 production by monocytes is highly influenced by endogenously produced IL-10. The monocytes from AD patients showed normal production levels of IL-6 and IL-10, a two-fold, but non-significant decrease in IL-12 production, and a significantly (three-fold) higher PGE₂ production than those from non-atopic controls. Here we show for the first time that enhanced PGE₂ production by monocytes in AD is not accompanied by a general rise in cytokine production. We conclude that AD is indeed associated with an increased PGE₂/IL-12 production ratio by monocytes.     

CO-OPERATION OF IL-1 AND IL-2 ON T-CELL ACTIVATION IN MONONUCLEAR CELL CULTURES

In search of an optimized anti-cancer immunotherapy, the combination of IL-2 and IL-1 has been tried. In an in-vitro LAK model, this cytokine cocktail seemed to be quite promising. In our in-vitro model of IL-2 induced T-cell activation we have therefore investigated the co-operation of these two potent immunostimulators. Mononuclear cells were stimulated with CD3 activating antibody in the presence of different cytokines and blocking or neutralizing antibodies. Cytokine concentrations were detected in the supernatants with ELISA. Intracellular IFN-γ and IL-4 in the different T-cell subsets was measured by flow cytometry. IL-1 and IL-1 receptor antagonist (IL-1Ra) were up-regulated by IL-2, this was achieved independently of IL-12 or CD40/CD40L interaction. As a negative feedback mechanism, IL-1β induced its natural antagonist, IL-1Ra. Both endogenous and exogenous IL-10 suppressed IL-1β and induced IL-1Ra, thus markedly decreased the amount of functional IL-1. The combination of IL-2 and IL-1β lead to a mildly increased Interferon-gamma (IFN-γ) secretion (+20%, p < 0.05), however, this appeared to be the result of an increased IFN-γ production per secreting cell, rather than of an increased recruitment of non-secreting cells. Similarly, IL-6 was also induced in an additive fashion (+30%, p < 0.05). For both cytokines, this effect could be significantly augmented by neutralizing IL-1Ra. Concentrations of IL-2 induced IL-10 and soluble Fas ligand (sFasL) were not affected by IL-1β. We were thus able to demonstrate that IL-1 relays its activity through different pathways than IL-2. Furthermore, we could show that the potentially synergistic action of IL-2 and IL-1 was hindered by the simultaneous induction of signficant amounts of IL-1Ra. From the latter findings we conclude that the combination of IL-2 and IL-1 for cytokine-induced anti-tumor activity may not, but a combination of IL-2 and anti-IL-1Ra might prove beneficial.     

刀豆蛋白A对帕金森患者外周血单个核细胞分泌IL-10和IFN-γ的作用

目的:观察帕金森病(PD)病人外周血单个核细胞(PBMC)经刀豆蛋白A(Co-nA)诱导培养后分泌白介素-10(IL-10)和干扰素-γ(IFN-γ)的能力。方法:23例PD患者分为早中期组(12例)和晚期组(11例),24例健康人群作为对照组,分离各组外周血单个核细胞,并用ConA诱导刺激。采用ELISA分别检测各组培养上清液中IL-10和IFN-γ含量。结果:对照组和早中期组PD患者经ConA诱导培养的PBMC分泌IL-10水平显著高于普通培养(P<0.05);晚期组分泌IL-10水平明显低于对照组和早中期组(P<0.01)。各组PD患者PBMC分泌IFN-γ水平ConA培养比普通培养都有升高,早中期组最高(P<0.01);PD早中期组ConA培养的PBMC分泌IFN-γ水平显著高于对照组和晚期组(P<0.01)。结论:刀豆蛋白对PD患者PBMC分泌IL-10和IFN-γ有促进作用;免疫机制在PD发病和发展中起着重要的作用。     

Th1 (IL-2, interferon-gamma (IFN-γ)) and Th2 (IL-10, IL-4) cytokine production by peripheral blood mononuclear cells (PBMC) from patients with systemic lupus erythematosus (SLE)

We investigated the production of IL-2, IFN-γ, IL-10 and IL-4 by PBMC from 24 patients with SLE and 10 healthy individuals. Basal and mitogen-stimulated (lipopolysaccharide and phytohaemagglutinin (LPS + PHA)) cytokine production was determined in a whole blood assay (WBA). Supernatants were collected and assayed with specific ELISAs. Although the IL-2 and IFN-γ contents did not differ significantly between patients and controls under both conditions, statistically significant correlations were found between each cytokine and disease activity (SLAM index) after stimulation (respectively, r= 0.501, P = 0.01 and r = 0.631, P = 0.001). PBMC IL-10 production was significantly higher for patients than controls (P = 0.05), but no correlation between IL-10 levels and the SLAM index was obtained. IL-4 production was not statistically different between SLE patients and controls. For stimulated WBAs, the IL-10/IL-2 and IL-10/IFN-γ ratios were significantly correlated with disease severity (P = 0.02; P = 0.001, respectively). Overall, our data suggest that SLE is characterized by an elevated production of IL-10, reflecting the basal state of activation of the immune system. During exacerbation of SLE, IL-2 and IFN-γ are synthesized in larger amounts and may cause the tissue damage observed.     

In vitro responsiveness to IL-18 in combination with IL-12 or IL-2 by PBMC from patients with bronchial asthma and atopic dermatitis

Interleukin (IL)-18 is a proinflammatory cytokine and is now recognized as an important regulator of both helper T cells (Th) 1 and 2 cytokine production. An increased IL-18 secretion has been reported in patients with allergic disorders. It is predominantly produced by activated macrophages, and synergizes with IL-12 and IL-2 to induce IFN-gamma synthesis, thereby promoting Th1 cytokine response. Paradoxically, IL-18, by itself, strongly induces immunoglobulin (Ig) E and allergic inflammation, indicating a role for IL-18 in promoting Th2 response. We investigated the inducing effect in vitro of combining IL-18 and Il-12 or Il-2 on Th1- and Th2-type cytokines production by peripheral blood mononuclear cells (PBMC) from patients with allergic diseases. PBMC derived from 44 allergic patients [23 bronchial asthma (BA) and 21 atopic dermatitis (AD)] and 20 healthy controls were cultured with IL-18 in the presence of phytohemagglutinin (PHA) and IL-12 or IL-2. The levels of IFN-gamma, IL-13, and IL-4 in the culture supernatants were measured using enzymatic immunoassaying. IFN-gamma production was detected in all cultures from nonallergic controls stimulated with IL-18 in the presence of IL-12; however, the results for five BA patients and five AD patients were under the detection limit for IFN-gamma. In collaboration with IL-2, IL-18 was able to induce IFN-gamma production by PBMCs from all nonallergic controls and all allergic patients, with the exception of one AD patient. Synergistic induction of IL-13 production was found in cultures with IL-18 + IL-2, and the IL-13 induction was significantly increased in BA patients when compared with that in nonallergic controls (P = 0.006). The stimulation by IL-18, even in combination with IL-2, failed to induce IL-4 production by PBMC from both nonallergic controls and allergic patients. Although the induction of IFN-gamma by IL-18 + IL-12 was impaired in around a quarter of the allergic patients, the impairment of the IFN-gamma production was completely restored by IL-2 in the presence of IL-18. Thus, IL-18 enhances IFN-gamma production through an IL-12-dependent pathway and exhibits synergism when combined with IL-2 in terms of enhanced IL-13 and IFN-gamma production, suggesting the involvement of IL-18/IL-12/IL-2 pathway in modulating Th1/Th2 cytokine response.     

Levels of IL-12 in the sera of patients with systemic lupus erythematosus (SLE)--relation to Th1- and Th2-derived cytokines

IL-12 is a cytokine that induces Th1-derived cytokines (interferon-gamma (IFN-gamma) and IL-2). The significance of IL-12 in human autoimmunity is no clear, and the serum levels of IL-12 in SLE are not clearly established. Therefore, we examined the levels of IL-12 in 39 patients with active SLE, with sandwich ELISA. The levels of IL-12 in patients were significantly higher than in normal subjects. Patients with high levels of IL-12 also had high levels of IFN-gamma, while their levels of IL-13 were significantly lower than in patients with normal levels of IL-12. Patients with pulmonary involvement had high levels of IL-12, and steroid therapy decreased the IL-12 level in three patients. In a retrospective study of seven patients, various changes of IL-12 and IL-13 were recognized before disease flare. Thus, in SLE patients, the level of IL-12 was increased and this increase was related to the change of Th1- or Th2-derived cytokines with some organ involvement.     

慢性丙型肝炎患者抗病毒治疗前PBMC细胞因子的研究

目的 研究准备抗病毒治疗的慢性丙型肝炎患者的免疫特点.方法 将30例慢性丙型肝炎患者和10例正常对照外周血单个核细胞(PBMC)体外培养72 h后,用ELISA法检测培养上清中细胞因子IL-2、IL-4、IL-10、IL-12、IFN-γ和TNF-α的浓度.结果 (1)慢性丙型肝炎患者PBMC培养上清中IFN-γ、IL-10和TNF-α的水平明显升高(P＜0.05),没有检测到IL-2、IL-4、IL-12的基础分泌.(2)不同病情患者间的细胞因子的分泌水平差异无统计学意义(P＞0.05).结论 慢性丙型肝炎患者体内TH2型细胞因子的分泌占优势.提示通过调整TH1/TH2失衡可能达到抗病毒治疗目的.     

IL-6 promotes immune responses in human ulcerative colitis and induces a skin-homing phenotype in the dendritic cells and Tcells they stimulate

Dendritic cells (DCs) control the type and location of immune responses. Ulcerative colitis (UC) is considered a Th2 disease mediated by IL-13 where up to one third of patients can develop extraintestinal manifestations. Colonic biopsies from inflamed and noninflamed areas of UC patients were cultured in vitro and their supernatants were used to condition human blood enriched DCs from healthy controls. Levels of IL-13 in the culture supernatants were below the detection limit in most cases and the cytokine profile suggested a mixed profile rather than a Th2 cytokine profile. IL-6 was the predominant cytokine found in inflamed areas from UC patients and its concentration correlated with the Mayo endoscopic score for severity of disease. DCs conditioned with noninflamed culture supernatants acquired a regulatory phenotype with decreased stimulatory capacity. However, DCs conditioned with inflamed culture supernatants acquired a proinflammatory phenotype with increased expression of the skin-homing chemokine CCR8. These DCs did not have decreased T-cell stimulatory capacity and primed T cells with the skin-homing CLA molecule in an IL-6-dependent mechanism. Our results highlight the role of IL-6 in UC and question the concept of UC as a Th2 disease and the relevance of IL-13 in its etiology.     

Difference in mononuclear cell cytokine profile of tuberculosis patients before and after treatment and its influence on in vitro multinucleate giant cell formation

The present study focuses on correlation of in vitro multinucleate giant cell (MGC) forming ability with cytokine production in case of tuberculosis patients before and after treatment. In vitro MGC formation was carried out by treating monocytes with culture supernatant of Con A or PPD stimulated peripheral mononuclear cells. MGC formation was significantly lower for monocytes of untreated patients compared to control monocytes when incubated with respective autologous culture supernatant. MGC forming ability increased significantly for monocytes of treated patients incubated with autologous culture supernatant at the end of two months of treatment. Analysis of the supernatants revealed higher IL-10 levels and lower IFN-γ and IL-2 levels in untreated patients compared to treated patients and controls. The findings suggest that changes in IL-10, IFN-γ and IL-2 levels produced by mononuclear cells of patients before and after treatment might influence the functionality of monocytes and thereby the pathology of tuberculosis.