The Immunological Pregnancy Protective Effect of Progesterone Is Manifested via Controlling Cytokine Production

PROBLEM: This study was aimed at investigating the involvement of an altered cytokine pattern in the immunomodulatory and anti-abortive effects of a progesterone-induced immunomodulatory protein (PIBF). METHOD: PIBF expression on lymphocytes of healthy pregnant women and from women at risk for premature pregnancy termination was determined. In sera of the same women TNFα was quantified by a bioassay using L929 cells. NK activity was determined by a single cell cytotoxicity assay. Cytokine production of the lymphocytes or murine spleen cells was measured by ELISA or detected by immunocytochemistry. In pregnant mice endogenous PIBF activity was neutralized by anti-PIBF IgG. RESULTS: Sera of women at risk for premature pregnancy termination contained significantly higher concentrations of TNFα than those from healthy pregnant women and PIBF expression on the lymphocytes was inversely related to serum concentration of TNFα. Increased NK activity of lymphocytes after neutralization of endogenous PIBF activity is corrected by anti-IL2 treatment and PIBF inhibits IL12 expression on activated lymphocytes. PIBF increases IL-10 production by activated spleen cells. In pregnant mice, neutralization of endogenous PIBF activity by specific antibody results in increased resorption rate and reduced splenic IL-10 production. CONCLUSIONS: Our data allow the assumption that via blocking IL-12 production PIBF inhibits NK activation with a concomitant reduction of TNFα levels. Disturbances in this system might lead to the expression of the known synergistic effect of IL-12 and TNFα, resulting in a Th1 type cytokine dominance and pregnancy termination.     

胸腺五肽治疗实验性自身免疫性脑脊髓炎的实验研究

目的 应用胸腺五肽(thymopentin,TP-5)干预实验性自身免疫性脑脊髓炎(experiment autoimmue encephalomyelitis,EAE)大鼠,探讨该药物对EAE的治疗作用及其机制.方法 以豚鼠全脊髓匀浆(guinea pig spinal cord homogenate,GPSCH)与完全弗氏佐剂(CFA)为抗原免疫Wistar大鼠建立EAE模型.Wistar大鼠随机分为正常对照组、EAE组、地塞米松(dexamethasone,DXM)组、TP-5小剂量组、TP-5大剂量组.采用双抗体夹心ELISA法检测Wistar大鼠免疫后7、14、21 d不同时间点血清中IL-12、IL-10的含量.结果 与EAE组和TP-5大剂量组比较,TP-5小剂量组和DXM组大鼠的发病率和临床评分显著性降低(P＜0.01);DXM组大鼠的发病率和临床评分低于TP-5小剂量组(P＜0.01).各个时间点EAE组、DXM组、TP-5小剂量组、TP-5大剂量组IL-12含量均较正常对照组明显升高(P＜0.01),免疫后14、21 d DXM组和TP-5小剂量组IL-12水平比EAE组低(P＜0.01);免疫后14、21 dDXM组、TP-5小剂量组IL-10水平与其余3组比较明显升高(P＜0.01).结论 TP-5对EAE有保护作用,其作用机制可能与上调IL-10水平以及下调IL-12水平有关,通过双向调节作用逆转TH1/TH2失衡.     

Altered microRNA Expression and Immunosuppressive Cytokine Production by Regulatory T Cells of Ulcerative Colitis Patients

Regulatory T (Treg) cells are essential for maintenance of peripheral tolerance and prevention of autoimmune diseases in part by producing immunosuppressive cytokines. Recently, microRNAs (miRNAs) have also been involved in autoimmune disorders, not least for their crucial role in the regulation of Treg biology and function. We simultaneously investigated the concentration of IL-35, IL-10, TGF-β, and sCD25 in supernatant of cell culture and the expression patterns of several miRNAs in CD4⁺CD25⁺ CD127^?/low FoxP3⁺ Tregs of ulcerative colitis (UC) patients. Significantly lower levels of IL-10 and IL-35 were observed in Treg cultures of UC patients. miR-21, miR-146a, and miR-155 levels were downregulated and miR-31 level was upregulated in Tregs of patients. Our results suggest that microRNAs may serve as a novel regulator in function and homoeostasis of UC Treg cells, providing a key role for them in pathophysiology of UC.     

Progesterone Suppression of Pregnancy Lymphocytes Is not Mediated by Glucocorticoid Effect

ABSTRACT: This study investigated whether the suppressive effect of progesterone on pregnancy lymphocytes is mediated by specific progesterone receptors. The effects of a competitive progesterone antagonist (RU486) and a specific glucocorticoid receptor blocker (RU43044) were tested on the release of a blocking factor by progesterone-treated pregnancy lymphocytes. RU 486 tested at an equal concentration as progesterone significantly inhibited the production of the blocking factor, while RU 43044 was without effect. These data suggest that in pregnancy, lymphocyte progesterone acts on specific progesterone receptors and glucocorticoid binding sites are not involved.     

Production of interleukins 10 and 12 by peripheral blood mononuclear cells (PBMC) in chronic hepatitis C virus (HCV) infection

We previously reported that interferon-gamma (IFN-γ) production by PBMC in response to HCV core protein was increased in patients with type C chronic liver disease. To understand better the pathophysiology of this disease, we evaluated production of IL-10 and IL-12 by PBMC from 41 patients with chronic HCV infection, including asymptomatic HCV carriers with persistently normal serum ALT values. IL-10 is known to inhibit many effector functions of the immune system, suppressing Th1-type cell development, while IL-12 stimulates differentiation of Th1-type cells, facilitating cell-mediated immunity. IL-10 production was determined by culturing lymphocytes with concanavalin A (Con A), while IL-12 was produced by monocytes in the presence of Staphylococcus aureusCowan 1 (SAC) with or without recombinant HCV core protein, respectively. The cytokine levels in culture supernatants were measured by ELISA. Spontaneous IL-10 production was greater in patients with chronic hepatitis (CH) (229±119 pg/ml, P<0.01) and liver cirrhosis (LC) (185±88 pg/ml, P<0.05) than in controls (119±27 pg/ml), while it was decreased during IFN treatment (70±25 pg/ml). Both HCV core protein and Con A enhanced IL-10 production by cells from HCV-infected patients. IL-12 was not detectable in medium alone cultures, and SAC-induced IL-12 production did not differ between various patient groups and controls. Simultaneous addition of HCV protein resulted in an increase of IL-12 production in chronic liver disease compared with SAC-alone cultures. Addition of IL-10 to the cultures equally suppressed IFN-γ production for both controls and patient groups, but the enhancing effect of IL-12 on IFN-γ production was significantly less in LC than in controls and other patient groups. The findings suggest that secretion of IL-10/IL-12 by cells from control individuals and various patient groups may be different, and that the cytokines might show different effects on IFN-γ production by some cells.     

IL-12和IL-10与实验性自身免疫性脑脊髓炎大鼠发病的相关性

目的:探讨IL-12及IL-10与实验性自身免疫性脑脊髓炎(EAE)大鼠发病的相关性.方法:以豚鼠全脊髓匀浆与福氏完全佐剂为抗原免疫Wistar大鼠建立EAE模型.取脑、脊髓组织石腊包埋, 病理切片, 光镜观察;采用双抗体夹心法ELISA检测Wistar大鼠免疫后7、14、21 d不同时间段血清中IL-12、IL-10的含量.结果:EAE组免疫后第7天IL-12水平即出现明显上调, 早于临床症状的发生, 随免疫后时间的延长, IL-12表达呈逐渐增高后缓慢下降的变化趋势, 并且与EAE大鼠病情评分呈明显正相关(r=0.951, P＜0.01).免疫后第21天EAE组IL-10水平与CFA组和NS组比较明显升高(P＜0.01).结论:IL-12和IL-10分别与EAE的发病和缓解密切相关.     

饮食性缺铜、缺锌对小鼠细胞因子产生的影响

３周龄小鼠饲用６周缺铜饮食后，出现胸腺萎缩、肝脏肿大以及明显的缺铜指征，包括血清Ｃｐ活性、肝Ｃｕ含量、ＣＣＯ和Ｃｕ，Ｚｎ－ＳＯＤ活性明显下降。缺钢小鼠产生的ＴＮＦ－α、ＩＬ－１和ＩＬ－６水平明显低于正常组小鼠。小鼠饲予７周缺锌饮食后，出现明显脱毛，虽然肝Ｚｎ含量降低不明显，但ＴＮＦ－α、ＩＬ－１和ＩＬ－６活性明显降低，说明上述细胞因子是小鼠缺锌的敏感指征之一。本文结果显示正常Ｃｕ、Ｚｎ水平对ＴＮＦ－α、ＩＬ－１和ＩＬ－６产生的重要性，并提示这些细胞因子的改变可能是缺铜、缺锌引起的免疫功能损害的细胞、分子学机理之一。     

Increase in the production of interleukin-6, interleukin-10, and interleukin-12 by lipopolysaccharide-stimulated peritoneal macrophages from women with endometriosis

PROBLEM: To verify whether the peritoneal macrophage (PM) is activated in endometriosis. METHOD OF STUDY: We examined the synthesis of nitric oxide (NO), total antioxidant, interleukin (IL)-6, IL-10, and IL-12 by cultured PMs, which were either unstimulated or stimulated with lipopolysaccharide (LPS), from women with endometriosis (early, n = 12; advanced, n = 11) or without endometriosis (n = 13). RESULTS: After stimulation with 2 ng/mL LPS for 24 hr, PMs from women with early-stage endometriosis secreted more NO, IL-6, and IL-10 than the controls. Higher IL-12 levels were noted in women with advanced endometriosis when compared with the controls. After 2 ng/mL-LPS stimulation for 24 hr, we also detected higher total antioxidant levels in the advanced-endometriosis group than those in the early-endometriosis group. CONCLUSION: The increased production of IL-6, IL-10, and IL-12 by stimulated PMs confirmed previous observations that the PM is the principle source of these cytokines in peritoneal fluid.     

IL-10-Producing Lymphocytes in Inflammatory Disease

IL-10 is an anti-inflammatory cytokine that plays a significant role in controlling inflammation and modulating adaptive immune responses that cause tissue damage. IL-10-producing lymphocytes contribute to the delicate balance between inflammation and immunoregulation, and are thus regarded as a kind of “regulatory cells.” Dysregulation of these cells is linked with susceptibility to numerous inflammatory diseases. In this review, we summarized what is known about the regulatory effects of IL-10 produced by lymphocytes, including T cells, B cells and natural killer cells, in inflammatory diseases. We hope to augment immune responses or prevent immunopathology through making some small changes in the levels of IL-10 produced by lymphocytes, or in the cellular location where it is produced.     

Progesterone regulates IL12 expression in pregnancy lymphocytes by inhibiting phospholipase A2

PROBLEM: Progesterone-induced blocking factor (PIBF) is one of the pathways that mediate the immunological effects of progesterone. PIBF inhibits natural killer (NK) cytotoxic activity. Recently we showed that neutralization of PIBF results in an increased interleukin (IL)-12 expression, which is corrected by cyclooxygenase inhibitors. As exogenous arachidonic acid (AA) voids the NK blocking effect of PIBF, it is likely that PIBF acts before the level of the cyclooxygenase enzyme. Therefore in this study we investigated the effect of PIBF neutralizing antibody and simultaneous phospholipase A2 inhibitor quinacrine (Q) treatment on IL-12 production. METHODS: Pregnancy lymphocytes were treated with anti-PIBF antibody or lipopolysaccharide (LPS) as a positive control, in the presence or absence of Q. IL-12 expression by PBMC was detected by immunocytochemistry. RESULTS: Neutralization of PIBF as well as LPS treatment resulted in an increased IL-12 expression, which was corrected by simultaneous Q treatment. Pre-treatment of lymphocytes with progesterone prevented the stimulating effect of LPS on IL-12 production. CONCLUSION: Progesterone binding of the lymphocytes is followed by the release of PIBF that inhibits AA release. The subsequent block of prostaglandin synthesis reduces IL-12 production and results in a lowered cytotoxic NK activity, which may contribute to a normal pregnancy outcome.     

Regulation of immune responses by interleukin-27

Summary: Cytokine-mediated immunity plays a crucial role in the pathogenesis of various diseases including autoimmunity. Recently, interleukin-27 (IL-27) was identified, which, along with IL-12, IL-23, and IL-35, belongs to the IL-12 cytokine family. These family members play roles in the regulation of T helper (Th) cell differentiation. IL-27 is unique in that while it induces Th1 differentiation, the same cytokine suppresses immune responses. In the absence of IL-27-mediated immunosuppression, hyper-production of various pro-inflammatory cytokines concomitant with severe inflammation in affected organs was observed in IL-27 receptor α chain (WSX-1)-deficient mice infected with Trypanosoma cruzi. Experimental allergic or inflammatory responses were also enhanced in WSX-1-deficient mice. The immunosuppressive effects of IL-27 depend on inhibition of the development of Th17 cells (a newly identified inflammatory T-helper population) and induction of IL-10 production. Moreover, administration of IL-27 or augmentation of IL-27 signaling suppresses some diseases of autoimmune or allergic origin, demonstrating its potential in therapy of diseases mediated by inflammatory cytokines. In this review, we discuss recent studies on the role of IL-27 in immunity to parasitic and bacterial infections as well as in allergy and autoimmunity in view of its pro- and anti-inflammatory properties.     

Cytokine changes in postmenopausal women treated with estrogens: a placebo-controlled study

PROBLEM: Hormone replacement therapy (HRT) is being increasingly used in postmenopausal women. Sex steroids are known to affect the immune system in several ways, although this is mainly based on clinical observations and experimental studies. METHOD OF STUDY: We studied the in vivo effects of transdermal estrogens (50 microg 17 beta-Estradiol/24 hr) on cytokine production in postmenopausal women. A total of 17 women were randomized to either placebo (n = 7) or active estrogen therapy (n = 10) for 14 weeks, with addition of oral medoxyprogesterone acetate 10 mg daily during the last 2 weeks in both groups. Secretion of the cytokines IFN-gamma, IL-4, IL-10 and IL-6 in blood mononuclear cells was determined, spontaneously and after stimulation with common vaccination antigens and mitogen, using the cell ELISA technique. RESULTS: IL-6 production after stimulation with purified protein derivate (PPD) decreased in the estrogen treated group (P < 0.01). Mitogen-induced IL-6 production was reduced in the estrogen treated group in contrast to an increase in the placebo group, leading to a significant difference (P < 0.01) between the groups after 12 weeks of treatment. This difference was eliminated after an addition of progestagens for 2 weeks. No significant changes were noted for IFN-gamma, IL-4 or IL-10 in relation to estrogen or placebo treatment. CONCLUSIONS: In the present controlled study, the main in vivo effect of estrogens was a decrease in IL-6 production, indicating a possible beneficial effect of estrogen therapy.     

IL－10对佐剂性关节炎大鼠腹腔巨噬细胞及脾淋巴细胞诱生IL－8的影响

本文研究了ＩＬ－１０对佐剂性关节炎（ＡＡ）大鼠腹腔巨噬细胞（Ｍφ）及脾淋巴细胞在体外诱生ＩＬ－８的影响，还探讨了ＩＬ－１０经腹腔注射后对ＡＡ大鼠的治疗作用以及在体内对ＩＬ－８合成的影响，并利用核酸杂交技术初步探讨了ＩＬ－１０的作用机制。结果表明，ＡＡ大鼠腹腔Ｍφ及脾淋巴细胞分泌ＩＬ－８的能力明显高于正常大鼠。在体外ＩＬ－１０能显著下调ＩＬ－８的表达。ＡＡ大鼠经ＩＬ－１０治疗后症状明显改善，ＩＬ－８的合成能力降低。ＩＬ－１０能明显下调正常大鼠腹腔ＭφＩＬ－８ｍＲＮＡ表达。总之，ＩＬ－１０在体内外均显著抑制ＩＬ－８的合成，并具有良好的抗炎活性，从而为临床治疗类风湿关节炎（ＲＡ）提供了新制剂。     

Cytokine production by natural killer lymphocytes in follicular and luteal phase of the ovarian cycle in humans

PROBLEM: The aim of this study was to test the hypothesis that, during luteal phase of the ovarian cycle, as compared with follicular phase, the cytokine productive capacity of peripheral natural killer (NK)-lymphocytes in humans is shifted towards a "Th2-type"-like response. METHOD OF STUDY: Intracellular Th1 and Th2 cytokine production by in vitro activated peripheral NK-lymphocytes in a whole blood preparation of the follicular and the luteal phase of the ovarian cycle was measured by flow cytometry. RESULTS: There was no difference in interferon (IFN)-gamma, interleukin (IL)-2, IL-4, and IL-10 cytokine production in activated NK-lymphocytes when comparing luteal phase with follicular phase of the ovarian cycle. However, there was a significant increase in peripheral NK-lymphocyte number in luteal phase compared with follicular phase. CONCLUSION: The cytokine productive capacity of peripheral NK-lymphocytes is not shifted towards a "Th2-type"-like response in the luteal phase as compared with the follicular phase of the ovarian cycle in humans.     

Estradiol Down-Regulates LPS-Induced Cytokine Production and NFkB Activation in Murine Macrophages

PROBLEM: In vivo and in vitro studies have indicated that estradiol can affect cytokine production in different cell types. This study examines whether estradiol affects inflammatory cytokine production by murine splenic macrophages. METHODS: Mouse splenic macrophages were first treated with 17β-estradiol, followed by lipopolysaccharide (LPS) stimulation. The production of cytokines by macrophages with or without estradiol treatment was determined at both the protein and mRNA levels. The nuclear factor-kB (NFkB) activity of activated mouse splenic macrophages was also evaluated by electrophoretic mobility shift assay. RESULT: Our results show that 17β-estradiol decreases LPS-induced IL-1α, IL-6, and TNF-α production but not IL-10, IL-12, and macrophage inflammatory protein (MIP) production by splenic macrophages. Furthermore, inhibition of cytokine production by 17β-estradiol was associated with a decreased LPS-induced NFkB-binding activity. CONCLUSION: Because cytokines are important mediators of immune function, the alteration of cytokine production by 17β-estradiol may thus have a profound effect on the outcome of immune response during inflammation.