Production of interleukin-1 and tumor necrosis factor by bone marrow-derived macrophages: effect of cisplatin and lipopolysaccharide

Mature macrophages derived in vitro from bone marrow progenitors under the influence of either L929 CM (a source of M-CSF) or GM-CSF have been shown to differ morphologically and functionally. Treatment of these bone marrow-derived macrophages with cisplatin or LPS resulted in the expression of enhanced tumoricidal activity and the production of significant amounts of extracellular and membrane-associated IL-1 and TNF. rGM-CSF-derived bone marrow macrophages produced higher amounts of TNF and IL-1 activity than L929CM-derived macrophages. Untreated bone marrow-derived macrophages showed little IL-1 and TNF activity. Bone marrow macrophages cultured with medium alone also did not respond to cisplatin or LPS for the production of IL-1 and TNF. Neutralization studies with anti-IL-1 and anti-TNF antibodies inhibited the IL-1 and TNF activity of bone marrow-derived macrophages. These results suggest that cisplatin or LPS treatment of murine bone marrow-derived macrophages results in increased expression of both released and membrane-associated IL-1 and TNF.     

CELL ADHESION MOLECULE EXPRESSION WITHIN HUMAN GLOMERULAR AND KIDNEY ORGAN CULTURE

A glomerular and kidney organ culture method was developed to study cytokine inducibility of adhesion molecules and MHC antigen expression. Glomerular cells showed constitutive expression of intercellular cell adhesion molecule-1 (ICAM-1) and MHC class I and II antigens, but not vascular cell adhesion molecule-1 (VCAM-1), E-selectin, or P-selectin. Expression of E-selectin on glomerular endothelial cells (ECs) was induced by interleukin-1 (IL-1), tumour necrosis factor (TNF), interferon-γ (IFN-γ) and granulocyte/macrophage-colony stimulating factor (GM-CSF); this induction was inhibited by transforming growth factor beta (TGFβ) and by IL-4. P-selectin expression was never seen within glomeruli. VCAM-1 was constitutively expressed by Bowman's capsule and proximal tubules and was weakly induced on glomerular ECs by TNF and IL-4 in combination. Glomerular endothelial ICAM-1 expression was increased by IL-1, TNF, IFN-γ, and GM-CSF, while TGFβ inhibited induction by TNF and IL-1. Expression of MHC class I and II antigens by glomerular ECs was constitutive; further upregulation of MHC class II by IFN-γ was observed. These studies suggest that leukocyte–endothelial cell interactions that occur within the kidney follow broadly similar principles as are proposed to occur elsewhere in the body but, in addition, there are subtle differences that reflect local conditions. © 1997 by John Wiley & Sons, Ltd.     

小鼠骨髓源性巨噬细胞极化的体外诱导方法探究

目的:探究小鼠骨髓前体细胞体外诱导成为不同极化状态(M1和M2)巨噬细胞的优化方法。方法:健康C57BL/6小鼠麻醉处死,收集其股骨和胫骨腔内容物,经筛网过滤、红细胞裂解后,在RPMI-1640完全培养基中培养16h,收集未贴壁的骨髓前体细胞重新接种于6孔板。根据培养基中所加刺激剂的种类、剂量不同进行实验分组,于不同时点收集细胞,光镜下观察各组细胞形态学变化,流式细胞术及RT-qPCR检测不同极化状态巨噬细胞的相应标志物。结果:(1)小鼠骨髓前体细胞经50μg/L巨噬细胞集落刺激因子(M-CSF)刺激72 h后,CD11b阳染率达到90%以上;刺激96 h后,F4/80的阳染率达到95%以上。40μg/L的粒-巨噬细胞集落刺激因子(GM-CSF)刺激96 h后,CD11b阳染率也达到了90%以上,F4/80阳染率至144 h达到峰值(58.2%);(2)在M-CSF刺激所得单核-巨噬细胞的基础上,给予M1型巨噬细胞诱导剂(25μg/L LPS和10μg/L IFN-γ)刺激24 h,可见CD86的阳染率大于90%;给予M2型巨噬细胞诱导剂(20μg/L IL-4和IL-13)刺激后CD206的阳染率始终处于较低水平(10%左右);(3)在GM-CSF刺激的基础上,给予M1型巨噬细胞诱导剂刺激24 h,可见CD86的阳染率大于90%;而当细胞接受M2型巨噬细胞诱导剂刺激96 h,CD206的阳染率达68.98%;(4)RT-qPCR结果显示在给予相应极化诱导剂刺激后,M1型巨噬细胞标志物诱导型一氧化氮合酶(iNOS)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、IL-12,以及M2型巨噬细胞标志物:几丁质酶3样蛋白3(Chi3l3/Ym1)、甘露糖受体(MR)和精氨酸酶1(Arg-1)的mRNA表达均明显高于对照组(P<0.01)。结论:(1)C57BL/6小鼠骨髓前体细胞受到M-CSF或GM-CSF诱导后90%以上细胞均可向单核细胞分化,M-CSF可诱导90%以上的细胞为成熟巨噬细胞,GM-CSF可诱导58%的细胞为成熟巨噬细胞;(2)在M-CSF前期诱导的基础上,联合LPS和IFN-γ易于诱导出M1型巨噬细胞,但联合IL-4和IL-13难以获得M2型巨噬细胞;(3)在GM-CSF前期诱导的基础上,联合LPS和IFN-γ易于诱导出M1型巨噬细胞,联合IL-4和IL-13也可将大部分细胞诱导成为M2型巨噬细胞。     

小鼠骨髓源性巨噬细胞极化的体外诱导方法探究

目的:探究小鼠骨髓前体细胞体外诱导成为不同极化状态(M1和M2)巨噬细胞的优化方法。方法:健康C57BL/6小鼠麻醉处死,收集其股骨和胫骨腔内容物,经筛网过滤、红细胞裂解后,在RPMI-1640完全培养基中培养16h,收集未贴壁的骨髓前体细胞重新接种于6孔板。根据培养基中所加刺激剂的种类、剂量不同进行实验分组,于不同时点收集细胞,光镜下观察各组细胞形态学变化,流式细胞术及RT-qPCR检测不同极化状态巨噬细胞的相应标志物。结果:(1)小鼠骨髓前体细胞经50μg/L巨噬细胞集落刺激因子(M-CSF)刺激72 h后,CD11b阳染率达到90%以上;刺激96 h后,F4/80的阳染率达到95%以上。40μg/L的粒-巨噬细胞集落刺激因子(GM-CSF)刺激96 h后,CD11b阳染率也达到了90%以上,F4/80阳染率至144 h达到峰值(58.2%);(2)在M-CSF刺激所得单核-巨噬细胞的基础上,给予M1型巨噬细胞诱导剂(25μg/L LPS和10μg/L IFN-γ)刺激24 h,可见CD86的阳染率大于90%;给予M2型巨噬细胞诱导剂(20μg/L IL-4和IL-13)刺激后CD206的阳染率始终处于较低水平(10%左右);(3)在GM-CSF刺激的基础上,给予M1型巨噬细胞诱导剂刺激24 h,可见CD86的阳染率大于90%;而当细胞接受M2型巨噬细胞诱导剂刺激96 h,CD206的阳染率达68.98%;(4)RT-qPCR结果显示在给予相应极化诱导剂刺激后,M1型巨噬细胞标志物诱导型一氧化氮合酶(iNOS)、白细胞介素6(IL-6)、肿瘤坏死因子α(TNF-α)、IL-12,以及M2型巨噬细胞标志物:几丁质酶3样蛋白3(Chi3l3/Ym1)、甘露糖受体(MR)和精氨酸酶1(Arg-1)的mRNA表达均明显高于对照组(P<0.01)。结论:(1)C57BL/6小鼠骨髓前体细胞受到M-CSF或GM-CSF诱导后90%以上细胞均可向单核细胞分化,M-CSF可诱导90%以上的细胞为成熟巨噬细胞,GM-CSF可诱导58%的细胞为成熟巨噬细胞;(2)在M-CSF前期诱导的基础上,联合LPS和IFN-γ易于诱导出M1型巨噬细胞,但联合IL-4和IL-13难以获得M2型巨噬细胞;(3)在GM-CSF前期诱导的基础上,联合LPS和IFN-γ易于诱导出M1型巨噬细胞,联合IL-4和IL-13也可将大部分细胞诱导成为M2型巨噬细胞。     

Interferon-γ and interleukin-4 reciprocally regulate the production of monocytes/macrophages and neutrophils through a direct effect on committed monopotential bone marrow progenitor cells

We studied the direct effects of interferon-γ (IFN-γ) in single cell colony assays of CD34⁺HLA-DR++ bone marrow progenitor cells stimulated by either granu-locyte-colony-stimulating factor (G-CSF), interleukin(IL)-3, granulocyte/macro-phage-colony-stimulating factor (GM-CSF), combinations of these CSF or medium conditioned by the 5637 human bladder carcinoma cell line. In this culture system IFN-γ stimulated monocytic colonies (CFU-M) no matter which CSF or CSF combination was used to support them and inhibited granulocytic colonies (CFU-G) if they were generated in the presence of G-CSF. IL-4 antagonized the myelopoietic effects of IFN-γ: the IFN-γ induced suppression of G-CSF-supported CFU-G, as well as the stimulation of CFU-M, were reversed by IL-4. In all cultures, IFN-γ had a limited, but statistically non-significant, inhibitory effect on CFU-GM, which was not affected by the presence of IL-4. These data show that IFN-γ and IL-4 reciprocally regulate the generation of myeloid cells involved in humoral (neutrophils) and cellular (macrophages) immune responses through a direct effect on monopotential myeloid progenitor cells.     

HCMV感染对单核细胞HLA－DR表达的影响

本文采用细胞ＥＬＩＳＡ法，研究发现人巨细胞病毒（ＨＣＭＶ）感染对单核细胞ＨＬＡ－ＤＲ的影响。结果表明ＨＣＭＶ感染后１ｄ，单核细胞ＨＬＡ－ＤＲ表达显著增高（Ｐ＜０．０１），以后逐渐降低，ｄ５降至对照水平；ＩＦＮγ（５００Ｕ／ｍｌ）．ＴＮＦ（２５０Ｕ／ｍｌ）、ＩＬ－６（５００／ｍｌ）、ＩＬ－１（５００／ｍｌ）均能不同程度地刺激单核细胞ＨＬＡ－ＤＲ表达；ＨＣＭＶ感染后，细胞因子刺激ＨＬＡ－ＤＲ表达的水平在感染后ｄ５，较对照组均显著降低（Ｐ＜０．０１）；ＩＬ－１＋ＩＦＮ－γ及ＴＮＦ＋ＩＦＮ－γ在刺激单核细胞ＨＬＡ－ＤＲ表达时有协同作用；ＨＣＭＶ感染后，ＩＦＮ－γ＋ＩＬ－１及ＴＮＦ＋ＩＦＮ协同刺激单核细胞ＨＬＡ－ＤＲ表达水平较对照组显著降低（Ｐ＜０．０１）。结果提示：在ＨＣＭＶ感染引起免疫抑制过程中，其引起单核细胞ＨＬＡ－ＤＲ表达降低是一重要机制。     

Interleukin-3 enhances cytokine production by LPS-stimulated macrophages

In addition to its hematopoietic activities, interleukin-3 (IL-3) can modulate macrophage functions. We have studied the production of interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor (TNF) by mouse peritoneal macrophages triggered by lipopolysaccharide (LPS) in the presence or absence of IL-3. Interleukin-3 at the concentration used (i.e., 100 U/ml) did not induce the production of any cytokines, whereas it enhanced significantly the secretion of IL-1, IL-6 and TNF by LPS-stimulated macrophages. The synergistic activity of IL-3 was observed over a wide range of Escherichia coli or Salmonella enteritidis LPS concentrations. No additive effect was noticed between IL-3 and granulocyte/macrophage colony-stimulating factor (GM-CSF), another factor able to enhance LPS-induced IL-1 production. Thus, IL-3 can potentiate the inflammatory response induced by endotoxin from Gram-negative bacteria through a potentiation of cytokine production.     

Effect of In vivo administration of cisplatin on the colony forming ability of murine bone marrow cells

In vitro colony forming ability of bone marrow cells obtained from cisplatin-treated C3H/He mice was studied. Mice were administered cisplatin in a single intraperitoneal dose of 10 mg/kg body wt, 24 h prior to the harvest of femoral bone marrow cells. Incubation of untreated bone marrow cells without any CSF in vitro showed little colony forming ability which was marginally enhanced in cisplatin-treated bone marrow cells. Presence of M-CSF (250 U/ml) or GM-CSF (250 U/ml) in the culture medium significantly augmented the colony forming ability of both untreated and cisplatin-treated bone marrow cells. In the presence of M-CSF, colony forming units - macrophage (CFU-M) were predominantly high in untreated bone marrow cells, followed with CFU - granulocyte - macrophage (CFU-GM). The number of CFU-M was significantly up-regulated in response to M-CSF in bone marrow cells obtained from cisplatin administered mice, whereas the number of CFU-GM remained unchanged, as compared to untreated mice. Both CFU-M and CFU-GM were enhanced in the presence of GM-CSF in untreated bone marrow cells. Cisplatin-treated bone marrow cells on incubation in the presence of GM-CSF showed a significant enhancement of CFU-M and GM as compared to untreated samples. IL-1 (100 U/ml) in the presence of M-CSF significantly up-regulated colony forming ability of cisplatin-treated bone marrow cells, whereas TNF (100 U/ml) inhibited the colony forming ability. These effects of IL-1 and TNF on the in vitro colony formation of cisplatin-treated bone marrow cells were reversed in the presence of anti-IL-1 and anti-TNF antibodies, respectively.     

Interferon-γ-inducing factor enhances T helper 1 cytokine production by stimulated human T cells: synergism with interleukin-12 for interferon-γ production

The novel cytokine interferon-γ-inducing factor (IGIF) augments natural killer (NK) cell activity in cultures of human peripheral blood mononuclear cells (PBMC), similarly to the structurally unrelated cytokine interleukin (IL)-12. IGIF has been found to enhance the production of interferon-γ (IFN-γ) and granulocyte/macrophage colony-stimulating factor (GM-CSF) while inhibiting the production of IL-10 in concanavalin A (Con A)-stimulated PBMC. In this study, when anti-CD3 monoclonal antibody (mAb)-stimulated human enriched T cells were exposed to IGIF, the cytokine dose-dependently enhanced the proliferation of the cells and this could be completely inhibited by a neutralizing antibody against IL-2 at lower concentrations of IGIF. Neutralizing antibody against IFN-γ had only insignificant inhibitory effects on T cell proliferation at higher concentrations of IGIF. Enzyme-linked immunosorbent assays (ELISA) revealed that, like PBMC, T cells exposed to IGIF produced large amounts of IFN-γ; however, changes in the production of IL-4 and IL-10 were minimal. IGIF, but not IL-12, significantly enhanced IL-2 and GM-CSF production in T cell cultures, as determined by CTLL-2 bioassay and ELISA, respectively; however, both IGIF and IL-12 enhanced IFN-γ production by the T cells. When T cells were exposed to a combination of IGIF and IL-12, a synergistic effect was observed on the production of IFN-γ, but not on production of IL-2 and GM-CSF. In conclusion, IGIF enhances T cell proliferation apparently through an IL-2-dependent pathway and enhances Th1 cytokine production in vitro and exhibits synergism when combined with IL-12 in terms of enhanced IFN-γ production but not IL-2 and GM-CSF production. Based on structural and functional differences from any known cytokines, it was recently proposed that this cytokine be designated interleukin-18.     

Cytokine regulation of the interleukin-1 receptor antagonist protein in U937 cells

A naturally occurring receptor-level antagonist of interleukin-1 (IRAPorIL-1 ra) has recently been cloned. To determine what stimuli might regulate this inhibitor, cytokines were tested for their effects on the steady-state level of IRAP mRNA in phorbol ester-differentiated U937 cells. The cytokines tested fell into one of three groups: (a) inducers: granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-4, (b) weak inducers (<2-fold stimulation): [IL-lα, IL-Iγ, and transforming growth factor-β (TGF-γ)] and (c) cytokines with no effect: (IL-2, platelet-derived growth factor, acidic fibroblast grouth factor, basic fibroblast growth factor, epidermal growth factor, granulocyte colony-stimulating factor, IL-3, IL-5, IL-6, interferon-y, multi-colony stimulating factor, tumor necrosis factor -a and IRAP itself. One hundred U/ml of either GM-CSF or IL-4 was the dose inducing peak IRAP mRNA expression; that peak expression occurred 12 h after addition of cytokine. GM-CSF induced a 34 ±15-fold increase in IRAP mRNA, and IL-4 induced a 15± 6-fold increase. In the same RNA samples, GM-CSF increased IL-ip mRNA 5.9 ± 1.7-fold, but IL-4 decreased IL-Iγ mRNA to half that of control levels (0.45 ± 0.17). Thus, a single stimulus (IL-4) decreased the expression of an agonist (IL-1) while it increased the expression of an antagonist (IRAP). When U937 cells were treated with both IL-4 and GM-CSF, the level of IRAP mRNA induced was additive, suggesting that the cytokines acted differently to increase IRAP mRNA levels. The level of IL-1 mRNA in cells treated with both IL-4 and GM-CSF was intermediate. Dexamethasone and cycloheximide inhibited all mRNA increases and did not reverse IL-4-induced decreases in IL-1 mRNA. These studies have identified two cytokines which induce IRAP in the monocytic cells studied, and have partially characterized the differential regulation of IL-1 and its antagonist, IRAP.     

Pro- and anti-inflammatory control of M-CSF-mediated macrophage differentiation

Macrophages play a key role in inflammation, tissue regeneration and tolerance. Their differentiation is regulated by tissue cells derived CSF-1 (M-CSF). The ability of macrophages to use autocrine M-CSF to control their differentiation and function remained controversial. In this study we investigated the regulation of M-CSF production by Th1 and Th2 cytokines (IFN-γ and IL-4) and tolerogenic stimuli – glucocorticoid dexamethasone in primary human monocyte derived macrophages. We show that IFN-γ and IL-4 efficiently induce production of M-CSF while glucocorticoid inhibited it in a dose dependent manner. Since glucocorticoid inhibits production of inflammatory cytokines we tested whether this effect is a result of inhibited M-CSF production. We showed that exogenous M-CSF rescues the ability of glucocorticoid-treated macrophages to produce TNF and IL-6 in response to LPS. These data indicate that glucocorticoid-treated macrophages retain the ability to respond to M-CSF. Analyzing the mechanism of this responsiveness, we showed that dexamethasone up-regulates surface expression of M-CSF receptor – CSF-1R. We conclude that the ability of macrophages to produce M-CSF secures macrophage differentiation under Th1 and Th2 conditions if tissue cells are unable to supply enough M-CSF. Increased surface expression of CSF-1R in tolerogenic conditions guarantees response to minute amounts of exogenous M-CSF.     

Interleukin-10 inhibits IgE-mediated nitric oxide synthase induction and cytokine synthesis in normal human keratinocytes

Human keratinocytes (HK) generate nitric oxide (NO) and proinflammatory mediators following activation with either IgE/anti-IgE immune complexes or a combination of lipopolysaccharide (LPS) and interferon-γ (IFN-γ). Recently, interleukin-10 (IL-10) has been shown to down-regulate various inflammatory responses and to be secreted by lymphocytes and dendritic cells during skin inflammatory reactions. We show here that IL-10 down-regulates the production of tumor necrosis factor (TNF)-α and IL-6 by activated HK. Also, induction of inducible nitric oxide synthase (iNOS) expression in HK by IgE/anti-IgE or LPS/IFN-γ is significantly reduced by the addition of IL-10. This effect is dose dependent and correlates with reduction of iNOS mRNA production and enzyme level. Therefore, IL-10 down-regulates NO-mediated HK inflammatory responses and may thus participate in the regulation of the skin immune network.     

Gene expression and secretion of cytokines and cytokine receptors from highly purified CD56+ natural killer cells stimulated with interleukin-2, interleukin-7 and interleukin-12

Interleukin (IL)-2 IL-7 and IL-12 stimulate the generation of lymphokine-activated killer activity and proliferation in natural killer (NK) cells by different mechanisms. In this study, we have compared the ability of IL-2, IL-7 and IL-12 to induce expression of cytokines and cytokine receptors both at the gene and protein level. IL-2 and IL-12 stimulated the CD56⁺ NK cells to release significant amounts of soluble p55 and p75 tumor necrosis factor receptor (TNFR), whereas less amounts of soluble TNFR were detected in IL-7-stimulated cultures. The p55 and p75 TNFR mRNA were expressed in resting NK cells, and no further induction was observed after cytokine-stimulation. Compared to the effects of IL-2, IL-7 induced lower, but substantial levels of granulocyte-macrophage colony-stimulating factor (GM-CSF) mRNA, and IL-7 was a more potent GM-CSF-inducing stimulus than IL-12. IL-12 induced higher levels of interferon-γ (IFN-γ) mRNA than did IL-2, and IL-7 only weakly influenced the IFN-γ expression. In accordance with the mRNA studies, IL-7 induced the secretion of high amounts of GM-CSF and no or low levels of IFN-γ, whereas high amounts of IFN-γ and low levels of GM-CSF were detected in supernatants from IL-12-stimulated NK cells. In conclusion, IL-2, IL-7 and IL-12 differentially regulate expression of cytokines and cytokine receptors both at the gene and protein level.     

Protective effect of SPR-901 (RBS) on the decrease of peripheral leukocyte number in 5-fluorouracil-treated mice.

5-Fluorouracil (5-FU) induces a decrease in the number of peripheral leukocytes (leukopenia), which is one of the major obstacles in the chemotherapy of cancer. The number of peripheral leukocytes decreased by day 4 in mice injected i.p. with 130 mg/kg of 5-FU and recovered to the normal level by day 8. Such a decrease by 5-FU was prevented to some extent by the oral administration of 30 mg/kg/day of SPR-901. Proliferative responses of bone marrow cells to granulocyte/macrophage colony stimulating factor (GM-CSF) or granulocyte colony stimulating factor (G-CSF) were suppressed by 5-FU treatment and their recoveries were enhanced by SPR-901. The serum level of IL-6 in 5-FU-treated mice was increased by SPR-901. All of the mice treated with 300 mg/kg of 5-FU in combination with SPR-901 survived over 15 days, however, only 4 of 10 mice treated only with 300 mg/kg of 5-FU survived. These results suggest that SPR-901 acts on macrophages directly or indirectly, giving rise to the enhanced production of IL-1, IL-6, and other factors. Some of the factors derived from SPR-901 activated macrophages, perhaps mainly IL-6, act on the early stage of development of multipotent bone marrow progenitors synergistically with GM-CSF.     

Effect of combination interleukin-3 (IL-3) and granulocytemacrophage colony stimulating factor (GM-CSF) on hematopoiesis administered to retrovirus-infected immunodeficient mice receiving dose-escalation zidovudine (AZT)

We have previously demonstrated that continuous administration of dose-escalation zidovudine (AZT) in either normal or LP-BM5 MuLV immunodeficient virus-infected mice (MAIDS) was associated with the development of anemia, neutropenia, and thrombocytopenia. Hematopoietic growth factors/cytokines are being evaluated to determine their efficacy in ameliorating the hematopoietic toxicity associated with AZT. In normal mice receiving AZT, an increase in only plasma erythropoietin and not GM-CSF, Meg-CSF or TNF-α has been reported. This article describes studies that investigated the effect of combination interleukin-3 (IL-3) and granulocyte-macrophage colony stimulating factor (GM-CSF) administered in normal non-viral, viral-infected, and viral-infected C57BL6 mice receiving dose-escalation AZT, i.e. 0.1 mg/ml, 1.0 mg/ml, and 2.5 mg/ml placed in the drinking water. Non-viral control mice responded to IL-3/GM-CSF by increasing erythropoiesis, myelopoiesis and platelet production measured by increased bone marrow and spleen derived erythroid, myeloid and platelet precursor stem cells cultured in semi-solid media. Virus-infected control mice not receiving IL-3/GM-CSF developed pancytopenia. Administration of IL-3/GM-CSF to virus-infected mice receiving dose-escalation AZT did not ameliorate the peripheral pancytopenia associated with immunodeficiency disease and AZT treatment, even though erythroid, myeloid and platelet precursor progenitor cells were increased at certain times when compared to either normal or viral-infected mice receiving IL-3/GM-CSF. These results indicate that the combination use of IL-3 and GM-CSF in vivo is only a partially effective growth factor/cytokine treatment to ameliorate the hematopoietic toxicity associated with the use of the anti-viral drug zidovudine.     

Induction of macrophage nitric oxide production by interferon-γ and tumor necrosis factor-α is enhanced by interleukin-10

Interleukin-10 (IL-10) has been reported to inhibit nitric oxide (NO) synthesis and microbicidal activity of interferon-γ (IFN-γ)-stimulated macrophages (MΦ) by preventing the secretion of tumor necrosis factor-α (TNF-α) which serves as an autocrine activating signal. We have examined the effects of recombinant IL-10 on the capacity of IFN-γ together with exogenous TNF-α to induce NO synthesis by bone marrow-derived MΦ. Under these conditions and in contrast to its reported deactivating potential, IL-10 strongly enhanced NO synthesis measured as nitrite (NO) release (half maximal stimulation at approximately 10 U/ml). IL-10 further increased NO production by MΦ stimulated in the presence of optimal concentrations of prostaglandin E₂, a positive modulator of MΦ activation by IFN-γ/TNF-α. Increased steady state levels of NO synthase mRNA were observed in 4-h IFN-γ/TNF-α cultures and enhanced NO release was evident 24 h but not 48 h after stimulation. These results suggest that the effects of IL-10 on MΦ function are more complex than previously recognized.     

B7-1 expression of Langerhans cells is up-regulated by proinflammatory cytokines,and is down-regulated by interferon-γ or by interleukin-10

Langerhans cells (LC) act as potent antigen-presenting cells (APC) for primary and secondary T cell-dependent immune responses. LC express several costimulatory and/or adhesion molecules such as B7/BB1, which has been implicated as one of the important determinants for professional APC. Recent studies have shown that B7/BB1 antigens comprise three distinct molecules termed B7-1, B7-2, and B7-3. We have examined the regulatory properties of B7-1 expression in LC using various cytokines including interleukin (IL)-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, IL-7, IL-10, interferon (IFN)-γ, granulocyte/macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor (TNF)-α. We have demonstrated: 1) that the B7-1 expression of LC is reproducibly up-regulated by either GM-CSF, TNF-α, IL-1α, IL-1β, or IL-4 in a dose- and time-dependent manner, 2) that GM-CSF exhibits the most active effect on B7-1 up-regulation in each experiment, 3) that IFN-γ or IL-10 profoundly inhibits the B7-1 expression of LC in a dose- and time-dependent manner, and 4) that the down-regulatory ability of IFN-γ or IL-10 neutralizes the activity of up-regulatory cytokines. The enhancing or inhibitory action of these cytokines on B7-1 expression occurs selectively because none of the cytokines consistently affects I-A expression of LC. These data suggest that the B7-1 expression of LC may be dynamically regulated by these up- and down-regulatory cytokines in normal and inflammatory epidermal microenvironment.