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.     

Recombinant interferon-gamma inhibits the expression of IL-4 receptors on human lymphocytes.

Interferon gamma (IFN-gamma) has been shown to inhibit many of the activities of IL-4, including the induction of IgE synthesis and the proliferation of T cell clones. Here we demonstrate that IFN-gamma is able to inhibit the expression of IL-4 receptors on peripheral blood lymphocytes from both normal healthy donors and from patients with chronic lymphocytic leukaemia. Inhibition was shown to be dose-dependent and did not affect the binding affinity of the receptor as shown by Scatchard analysis. IFN-gamma was unable to displace labelled IL-4 from its membrane receptor, which demonstrates that IFN-gamma and IL-4 do not compete for the same membrane binding protein. The ability of IFN-gamma to down-regulate IL-4 receptors may be important in controlling certain immune responses.     

IL-4 and interferon-gamma production in children with atopic disease.

In vitro studies have implicated reciprocal roles for IL-4 and interferon-gamma (IFN-gamma) in the regulation of IgE production. As elevated IgE is a major feature of atopic disease, an important question is whether an imbalance of IL-4 and IFN-gamma is present in vivo. The production of IL-4 and IFN-gamma in phytohaemagglutinin (PHA)-stimulated peripheral blood mononuclear cell cultures from atopic children was examined to determine if there is an increased production of IL-4 and/or a reduced production of IFN-gamma. Highly atopic children with IgE > 600 U/ml produced significantly more IL-4 and less IFN-gamma in vitro than age-matched non-atopic controls. Production of IL-4 and IFN-gamma in mildly atopic children was equivalent to controls. These findings indicate that highly atopic children have an imbalance of IL-4 and IFN-gamma production and that the degree of imbalance relates to severity of the atopic state. The ratio of in vitro IL-4: IFN-gamma production correlated positively with serum IgE, which suggests that the balance of these two cytokines is a factor in the regulation of IgE, in vivo. It remains to be determined whether this imbalance of IL-4 and IFN-gamma in the highly atopic children is the cause or result of the disease process.     

Increased IL-2, IL-4 and interferon-gamma (IFN-gamma) in steroid-sensitive nephrotic syndrome.

We investigated the production of cytokines by peripheral blood mononuclear cells (PBMC) and serum cytokine concentrations in children with steroid-sensitive idiopathic nephrotic syndrome (SSNS). PBMC from patients off treatment were collected during remission and relapse and cultured in medium alone or stimulated with calcium ionophore plus phorbol myristate acetate. Control PBMC were taken from healthy age-matched children. IL-2 was measured by bioassay, IL-4 by immunoradiometric assay, and IL-8 and IFN-gamma by ELISA. After 24 h culture without stimulation, IL-2, IL-4 and IFN-gamma were not detectable in the supernatant in any of the children. After stimulation, the supernatant concentrations of IL-2 (median 172 U/ml at 24 h) and IL-4 (160 pg/ml at 24 h; 210 pg/ml at 72 h) were significantly increased in relapse compared with remission (IL-2 37 U/ml; IL-4 65 pg/ml and 60 pg/ml) and controls (IL-2 69 U/ml; IL-4 40 pg/ml and 40 pg/ml) (P < 0.05). The concentration of IFN-gamma was not significantly increased in relapse compared with remission and controls (600, 325, and 145 U/ml, respectively, at 72 h). IL-8 concentrations were similar in relapse, remission and controls with stimulation (median 32, 40 and 40 ng/ml, respectively) and without (30, 17 and 10 ng/ml). IL-2 was not detectable in serum, but IL-4, IL-8 and IFN-gamma were measurable in about half the patients, both in relapse and remission, though were virtually undetectable in controls. We conclude that relapse of SSNS in children is associated with T lymphocyte activation with release of IL-2, IL-4 and IFN-gamma.     

Cross-regulatory role of interferon-gamma (IFN-gamma), IL-4 and IL-10 in schistosome egg granuloma formation: in vivo regulation of Th activity and inflammation.

This study examined the relationship of IL-4, IL-10 and IFN-gamma with regard to the local granuloma (GR) and draining lymph node (LN) response to Schistosoma mansoni eggs. Synchronized GR were induced in naive and schistosome-infected mice at the vigorous (8 weeks) and late chronic (20 weeks) stages. In LN cultures, IL-10 and IFN production peaked on day 4 and was greatest for 8 week-infected mice. All GR cultures contained IFN, but compared with naive mice IL-10 production was accelerated at 8 weeks and abrogated at 20 weeks, consistent with expansion and abatement of Th2 activity. Cytokine neutralization was performed in egg-challenged, naive mice that were adoptively sensitized with lymphoid cells from 8 week-infected donors. GR size, GR macrophage tumour necrosis factor (TNF) production and egg antigen-elicited IL-2, IL-4, IL-5, IL-10 and IFN were examined on day 4 of GR formation. Anti-IFN augmented GR area by 40%, increased local IL-4 and IL-10, but decreased IFN and TNF production. In corresponding LN cultures, IFN decreased by about 50%, while IL-2, IL-4, IL-10 and IL-5 increased by nearly two-, four-, five- and six-fold, respectively. Anti-IL-10 did not affect GR size or GR cytokines, but abrogated GR area by 40%, along with a reduction in local IL-4 and TNF production. In LN, IL-4 depletion reduced IL-4 and IL-5 by 60-70% and increased IFN levels. These results support the notion of a cross-regulatory network in which IFN inhibits Th2 and IL-10 inhibits Th1 cells. IL-4 fosters Th2 cells differentiation in LN, but also performs a critical recruitment function in the eosinophil-rich schistosome egg-induced GR, whereas IFN contributes to enhanced GR macrophage function.     

Interleukin-4 and interferon-gamma production by peripheral blood mononuclear cells from food-allergic patients

The aim of this study was to investigate whether patients with food allergy had a cytokine imbalance of interleukin (IL)-4 and interferon-gamma (IFN-γ) production. Diagnostic procedures including skin prick tests, determination of food-specific serum IgEs, and positive double-blind, placebo-controlled, food challenges identified 15 adult patients. They were compared with 15 age- and sex-matched healthy subjects. Peripheral blood mononuclear cells (PBMC) were incubated for 24, 48, and 72 h in the presence of phytohemagglutinin plus phorbol myristate acetate. After mitogen stimulation, culture supernatants from patients with food allergy contained significantly less IFN-γ but increased IL-4 when compared with healthy controls. Secretion of IL-4 was maximal at 24 h and IFN-γ secretion was maximal at 72 h. There was no correlation between cytokine secretion in vitro and serum IgE level. These findings demonstrated that an imbalance of IL-4 and IFN-γ production is present in food allergy, as documented in other allergic diseases, but other mechanisms are probably also involved.     

Dual action of IL-4 on mite antigen-induced IgE synthesis in lymphocytes from individuals with bronchial asthma.

Polyclonal IgE synthesis was efficiently induced by Dermatophagoides farinae (Df) antigen in freshly derived peripheral blood lymphocytes from mite-sensitive individuals with bronchial asthma. The in vitro IgE production was significantly correlated with total serum IgE values. The induced IgE synthesis was inhibited in a dose-dependent manner by antibodies to IL-4, indicating a role for endogenous IL-4. Although IL-4 alone increased IgE production, high concentrations (1-100 U/ml) of the cytokine inhibited Df antigen-stimulated production of IgE. However, low concentrations (0.001-0.01 U/ml) of IL-4 significantly enhanced Df antigen-induced IgE production, as did high doses of IL-4 when endogenous IL-4 was neutralized by antibodies to IL-4. Two other cytokines, IL-10 and interferon-gamma (IFN-gamma), showed contrasting actions, as judged from experiments with, exogenous cytokine and anti-cytokine antibodies: IL-10 enhanced and IFN-gamma inhibited Df antigen-induced IgE synthesis. Thus, mite-stimulated IgE production in lymphocytes from individuals with bronchial asthma appears to be regulated by at least three cytokines: IL-4, IL-10, and IFN-gamma.     

Chronic mucocutaneous candidiasis. I. Altered antigen-stimulated IL-2, IL-4, IL-6 and interferon-gamma (IFN-γ) production

Patients with chronic mucocutaneous candidiasis (CMC) present with persistent infections with the opportunistic yeast Candida. Impaired cell-mediated responses to Candida have been documented in CMC patients, but the defect remains poorly understood. The importance of Th1 cytokines in resistance and Th2 in susceptibility to Candida infections has recently been demonstrated in murine models. In our studies we evaluated production of IL-2 and IFN-γ (markers of Th1 type responses) as well as IL-4 and IL-6 (Th2 type markers) following stimulation with two kinds of Candida antigens (CAgs), polysaccharide antigens, tetanus toxoid and pokeweed mitogen. Our results demonstrate that CMC patients have impaired cytokine production upon in vitro stimulation with CAgs resulting in low or absent IL-2, increased IL-6 and either absent or increased IFN-γ production. Cytokine production following stimulation by other antigens was unaltered. The overall cytokine-producing capacity assessed through mitogen stimulation was also intact. Addition of IFN-α or IFN-γ to culture in an attempt to modify cytokine production did not have significant effects. Levels of soluble IL-6 receptors were not increased and could not account for increased IL-6 production. Our studies support the hypothesis that Candida antigens trigger a predominantly Th2 instead of a Th1 cytokine response in patients with CMC.     

Lower levels of IL-4 and IL-10 influence lipodystrophy in HIV/AIDS patients under antiretroviral therapy

Background

The role of interleukins in the pathogenesis of lipodystrophy in HIV/AIDS-patients is still not understood. The aim of this study was to evaluate the relationship between serum levels of interleukins between HIV/AIDS-patients with or without lipodystrophy, as well as between different subgroups of lipodystrophy (lipoatrophy, lipohypertrophy, mixed-fat-redistribution) and patients without lipodystrophy.

Immunoregulatory properties of IL-13 in patients with inflammatory bowel disease; comparison with IL-4 and IL-10

Activated monocytes with increased expression of proinflammatory cytokines play a major role in inflammatory bowel disease (IBD). Immunoregulatory cytokines such as IL-4 and IL-10 can effectively suppress the proinflammatory response of activated monocytes. IL-13 is a recently described antiinflammatory agent in vitro. The aim of our study was to determine the in vitro immunosuppressive capacity of IL-13, IL-4 and IL-10 in patients with IBD. Peripheral blood monocytes were isolated from 27 patients with ulcerative colitis (UC), 27 patients with Crohn's disease (CD) and 16 healthy controls. Cells were stimulated with pokeweed mitogen (PWM) after treatment with IL-13, IL-4 and IL-10, and secretion of IL-1β, tumour necrosis factor-alpha (TNF-α) and IL-6 was assessed using sandwich ELISA systems. Peripheral blood monocytes secreted significantly increased amounts of TNF-α and IL-6 under stimulation with PWM in patients with CD, while UC patients showed significantly elevated levels of IL-1β. The antiinflammatory cytokines IL-13, IL-4 and IL-10 were all capable of inhibiting monocyte secretion of IL-1β in a dose-dependent manner. With regard to IL-13 and IL-4, there was no significant suppression of TNF-α and IL-6 in patients with active IBD. By contrast, IL-10 was able to down-regulate all proinflammatory cytokines in active IBD as well as in controls. Proinflammatory cytokines from patients with inactive IBD could be significantly down-regulated by all three immunoregulatory cytokines. The inhibitory effect of IL-13 on TNF-α and IL-6 production in differentiated macrophages was diminished in IBD patients, as well as in controls. In disease controls we also observed a reduced inhibition of TNF-α and IL-6 after treatment with IL-13. In conclusion, the antiinflammatory activity of IL-13 is partially reduced in patients with active IBD. The hyporesponsiveness of activated and differentiated monocytes to IL-13 and IL-4 does not seem to be a disease-specific phenomenon.     

IgE production in atopic patients is not related to IL-4 production.

To analyse whether there is a general defect in T or B cell function in atopic individuals we have measured cytokine and IgE production by peripheral blood lymphocytes, isolated from 19 atopic donors (17 asthma/rhinitis and two dermatitis patients) in comparison with 19 non-atopic controls. After stimulation of lymphocytes with anti-CD2 and anti-CD28, we found no significant difference in IL-2, IL-4 and interferon-gamma (IFN-gamma) production. To examine the correlation between the production of IgE and IL-4, we stimulated lymphocytes with anti-CD2 and rIL-2. Under this condition both T cell IL-4 and B cell IgE production can be measured. No significant difference was found for the amount of IgE and IL-4 produced between the two groups (P > 0.05). The non-atopic donors showed a good correlation between IL-4 and IgE production (r = 0.70). Surprisingly, within the atopic group there was no correlation between IgE and IL-4 production at all (r = -0.04). The ratio of IgE to IL-4 was higher (although not significantly) in the atopic group. Our data suggest that in atopic donors IgE production is less dependent on IL-4, and that other cytokines are involved.     

Recombinant gp120 induces IL-10 in resting peripheral blood mononuclear cells; correlation with the induction of other cytokines.

Immunological abnormalities present in HIV-1-infected individuals often reflect an imbalance of cytokine production. The HIV-1 gp120 has the ability to induce a number of cytokines, and to enhance immunoglobulin release by normal peripheral blood mononuclear cells (PBMC) in vitro, in the absence of IL-2 production and of lymphoproliferation. This study provides evidence that gp120 is a potent IL-10 inducer in normal PBMC cultures. The pattern of other cytokines induced by gp120 includes interferon-alpha (IFN-alpha) and IFN-gamma, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-1 alpha and -beta, and not IL-2 and IL-4. These findings further define the pattern of cytokine release induced by gp120 on human resting PBMC. Furthermore, the present findings roughly parallel those observed both in the sera of patients and in the mononuclear cells from HIV+ individuals early after infection, suggesting that gp120 could be a good candidate as one of the agents responsible for cytokine dysregulation observed in HIV-1-infected individuals.     

IL-4 production is increased in cigarette smokers.

Cigarette smoking has been associated with both increases in serum levels of total IgE and an increased risk of developing allergic-like symptoms. IL-4 and interferon-gamma (IFN-gamma) have reciprocal roles in the regulation of IgE synthesis, and as such prompted us to evaluate, in smokers, the production of these two cytokines. We demonstrate that phytohaemagglutinin (PHA)-induced IL-4 production by peripheral blood mononuclear cells (PBMC) of smokers (n = 19) is significantly higher than that of non-smokers (n = 10, P < 0.005). In addition, PBMC from heavy smokers, defined by the number of cigarettes smoked per day, produced significantly higher levels of IL-4 than those of light smokers. No difference between the groups was found for IFN-gamma production. Our data suggest an imbalance in cytokine production occurring in individuals who smoke. This imbalance, favouring IL-4 production, may be part of the mechanism responsible for the observed increases in serum IgE and allergic-like symptoms associated with cigarette smoking.     

Increased levels of interferon-gamma (IFN-gamma), IL-4 and transforming growth factor-beta (TGF-beta) mRNA expressing blood mononuclear cells in human HIV infection.

Evidence has been presented for the involvement of IFN-gamma, IL-4 and TGF-beta in AIDS. Measured plasma levels may, however, poorly reflect in vivo production, since cytokines act auto- and paracrinally and have very short half life in plasma. In situ hybridization with complementary DNA oligonucleotide probes was used to enumerate blood mononuclear cells expressing cytokine messenger RNA (mRNA). HIV-infected patients had elevated blood levels of cells expressing each of the cytokines, with predominance for cells expressing TGF-beta mRNA. All AIDS patients included had elevated numbers of IL-4 mRNA-expressing cells, and levels of cells expressing this cytokine correlated inversely with counts of CD4+ cells in blood, reflecting the involvement of Th2-like cells in later stages of HIV infection. The described approach should be useful in further studies of cytokines in HIV infection and other diseases.     

肾病综合征患者血清IL-4和IL-10水平的变化及意义

目的通过观察肾病综合征(NS)免疫治疗前后白细胞介素-4(interleukin-4,IL-4)和IL-10水平的变化,探讨其临床意义。方法以ELISA检测52例NS患者在接受强的松和环磷酰胺治疗前及4周后血清IL-4和IL-10水平。结果NS患者血清IL-4水平显著增高(P<0.01),并与血清β_2微球蛋白呈显著正相关(n=52,r=0.352.P<0.05),血清IL-10水平与健康人无显著差异。治疗4周后血清IL-4和IL-10水平显著降低(P<0.05),尿蛋白排出量显著低于治疗前(P<0.05)。结论IL-4、IL-10参与了NS发病过程,强的松和环磷酰胺可通过调节IL-4和IL-10产生而调节NS的免疫紊乱,NS的免疫治疗方案可根据细胞因子水平(包括抗炎细胞因子IL-4和IL-10)调整。     

Expression profiling of IL-10-regulated genes in human monocytes and peripheral blood mononuclear cells from psoriatic patients during IL-10 therapy

Interleukin-10 (IL-10), originally identified as an inhibitor of pro-inflammatory cytokine production, exerts multiple immunomodulatory functions. Its ability to inhibit a Th1 response has been used in clinical trials for the treatment of inflammatory diseases including psoriasis. However, little is known about the molecular mechanisms of IL-10 functions. We aimed at identifying possible mediators of in vitro IL-10 treatment in monocytes by gene chip technology using Hu95a Affymetrix mRNA arrays with 12,000 genes. To prove relevance of the identified genes for the clinical situation we compared these in vitro results with genes being regulated by IL-10 in peripheral blood mononuclear cells from psoriatic patients undergoing IL-10 therapy. A high proportion of the 1,600 genes up-regulated and 1,300 genes down-regulated in vitro was found to be similarly regulated in vivo. Some genes, which were previously unknown to be regulated by IL-10, can be assigned to known IL-10 functions like e.g. the increase of pathogen clearance. Other new potentially immunomodulating genes have been identified to be regulated by IL-10, but their impact needs to be experimentally evaluated. We could confirm a recently reported up-regulation of heme oxygenase-1 (HO-1). However, we demonstrate that the anti-inflammatory mechanisms of IL-10 remain functional even when HO-1 is irreversibly inhibited.