Elevated local production of neopterin from alveolar macrophages in patients with internal lung diseases

• 1.1. We measured the neopterin level in the supernatant of cultured alveolar macrophages from patients with interstitial lung diseases (ILD patients) as a marker for the activation of alveolar macrophage.
• 2.2. In ILD patients, the supernatant neopterin level (40.1±7.8 pmol/ml) was significantly higher (P<0.01) than that in control subjects (10.0±1.6 pmol/ml).
• 3.3. We also found that macrophage-colony stimulating factor (M-CSF) and interleukin-2 (IL-2) augmented neopterin production from alveolar macrophage in both ILD patients (51.6±10.4 and 60.1±10.8 pmol/ml, respectively, P<0.01) and control subjects (28.1±6.0 and 25.7±4.9 pmol/ml, respectively).
• 4.4. These findings suggest that alveolar macrophages produce neopterin by M-CSF or IL-2.

     

Cytokines in the thymus: production and biological effects

All types of thymic cells are able to produce cytokines either spontaneously or after stimulation. The main producers of cytokines in the thymus are thymic epithelial cells (TEC) and thymocytes. Thymic cytokines act at short distance and their effects are limited by the internal space of the organ. The spectrum of biological effects of thymic cytokines is determined by the expression of cytokine receptors on the thymic cell surface. Some cytokines produced by the thymic cells of one type are supplied to cells of other types; other cytokines act as autocrine factors. Examples of paracrine thymic cytokines are IL-7 (produced by TEC or stromal fibroblasts induces CD4(-)CD8(-) thymocyte growth and differentiation) and INFgamma (produced by thymocytes, induces TEC activation). An example of an autocrine factor is IL-2, for which the producers and targets are thymocytes. The ability of thymocytes to produce cytokines and express cytokine receptors is gradually reduced as they mature from the stage of CD44(+)CD3(-)CD4(-)CD8(-) precursor cells to the stage of CD3(lo)CD4(+)CD8(+) cortical thymocytes; in the latter stage both these capacities become completely blocked. This change reflects the decrease of cytokine dependence of the respective processes. After the completion of the selection process, the capacity of thymocytes to produce cytokines and respond to their action is restored. Some differences in the function of the cytokine system in thymus and peripheral compartments of the immune system can be noted. 1. Unlike the periphery, where cytokine production and receptor expression are inducible, the synthesis of cytokines and expression of their receptors in the thymus has mainly a "spontaneous" character (or it is induced by cell-cell interactions). 2. Cytokines tightly interact, forming a cytokine network both at the periphery and in the thymus, but the structure of the peripheral and intrathymic cytokine network is different. The latter can be termed as a "minor cytokine network". Some peptide hormone-like factors play a significant role in the intrathymic cytokine network. 3. The principal role of thymic cytokines is to provide constitutive processes (migration and development of thymocytes, regulation of cell number in the cell populations, etc.), but not inducible ones (inflammation, immune response, etc.) as in the periphery. 4. The functions of some cytokines in the thymus can be significantly different from those in the periphery of the immune system. For example, proinflammatory cytokines act in the thymus as factors or cofactors of thymocyte or TEC activation, proliferation or differentiation. The key cytokines of Th1 and Th2 cells - IFNgamma and IL-4 - do not participate in the immune response but mediate the dialogue between thymocyte and TEC and play a role in autoregulating the thymocyte population. The functions of many cytokines in the thymus are not established up to now. Detailed analysis of the "minor cytokine network" and intrathymic cytokine effects will reveal some unknown events of thymus physiology.     

Inhibition of osteoclastogenesis by a phosphodiesterase 4 inhibitor XT-611 through synergistic action with endogenous prostaglandin E2

We examined the effect of a phosphodiesterase 4 (PDE4) inhibitor, 3,4-dipropyl-4,5,7,8-tetrahydro-3H-imidazo[1,2-i]-purin-5-one (XT-611) on osteoclast formation in three different mouse bone-marrow cell (BMC) culture systems. We confirmed that selective inhibitors of PDE4, including XT-611, among several PDE inhibitors decreased osteoclast formation in the BMC culture system. XT-611 also inhibited osteoclast formation in co-culture of mouse bone-marrow stromal cell line ST2 and adherent cell-depleted (ACD)-BMCs. However, it did not inhibit osteoclastogenesis in culture of ACD-BMCs alone in the presence of macrophage-colony stimulating factor (M-CSF) and soluble receptor activator of NF-kappaB ligand (sRANKL). XT-611 significantly increased prostaglandin E(2) (PGE(2)) production from ST2 cells and, in combination with PGE(2), synergistically increased cAMP concentration in osteoclast progenitors. In the ST2 co-culture system, XT-611 did not influence the expression of RANKL, osteoprotegerin and RANK mRNAs. By combined treatment with XT-611 and PGE(2) of ACD-BMCs, osteoclast multinucleation was clearly inhibited with decrease in the expression of calcitonin receptor mRNA, while the expression of RANK and c-fms (an M-CSF receptor) mRNAs was unchanged. These results indicate that the PDE4 inhibitor inhibits osteoclastogenesis by acting on osteoclast progenitors synergistically with PGE(2) secreted from stromal cells, but not by influencing the cell-to-cell interaction between stromal cells and osteoclast progenitors.     

巨噬细胞极化对心肌成纤维细胞活化的影响

目的 观察巨噬细胞极化上清对心肌成纤维细胞活化的影响。方法 提取SD大鼠的骨髓细胞和心肌成 纤维细胞。利用巨噬细胞集落刺激因子（M-CSF）处理骨髓细胞后,加入刺激因子：M0（无刺激因子）、M1（100 μg/L脂 多糖+10 μg/L干扰素-γ）、M2（20 μg/L白细胞介素-4）诱导巨噬细胞极化。将极化后的不同型别巨噬细胞及其培养 上清分别与心肌成纤维细胞共培养,分别设空白对照组、M0组、M1组和M2组,通过细胞免疫荧光检测心肌成纤维细 胞中纤维化蛋白的表达水平;实时荧光定量逆转录聚合酶链反应检测巨噬细胞和成纤维细胞特征分子的表达; Western blot检测纤维化相关蛋白及转化生长因子β受体（TGFβR）、血小板衍生生长因子受体（PDGFRs）信号通路活 化情况。结果 经M-CSF及相应刺激因子诱导,成功获得M1和M2型巨噬细胞。细胞共培养结果显示,与M0组相 比,M1组上清培养的心肌成纤维细胞中胶原蛋白1（Col1a1）和Col3a1的mRNA水平以及平滑肌肌动蛋白（α-SMA）表 达水平显著降低（P＜0.05）,而M2组上清培养的心肌成纤维细胞中Col1a1和Col3a1的mRNA水平以及α-SMA、结缔 组织生长因子（CCN2）表达水平显著升高（P＜0.05）。M1组上清培养的心肌成纤维细胞中PDGFRβ蛋白磷酸化水平 显著低于 M0 组（P＜0.01）,而 M2 组上清培养的心肌成纤维细胞中 PDGFRβ 蛋白磷酸化水平显著高于 M0 组（P＜ 0.05）。结论 M1型巨噬细胞上清能够抑制心肌成纤维细胞活化,而M2型巨噬细胞上清能够激活心肌成纤维细胞。 M1型巨噬细胞抑制纤维化的作用可能与抑制PDGFRβ通路的活化有关。     

Effects of naturin 2 on colony formation by hematopoietic progenitor cells in human umbilical cord blood mediated by induction of release of growth factors

Naturin 2, a health drink, contains a mixture of Chinese herb plants and is a potent immunomodulator. It has anti-tumor effects mediated by immune system. In the present study, low density (LD) and purified CD34+ cells (enriched for hematopoietic stem [HSC] and progenitor [HPC]) from human umbilical cord blood (CB) were assayed for colony formation in response to Naturin 2. First, we examined the in vitro activity of Naturin 2 on HPC. Naturin 2 by itself stimulated colony formation derived from either LD or CD34+ CB cells. The stimulatory effect by Naturin 2 was mediated by both direct and indirect action on HSCs/HPCs. The indirect action is via releasing of cytokines in the 5 day-conditioned media by LD CB cells with Naturin 2. The stimulatory activities in the 5 day-conditioned media (CM) could be blocked by the neutralization antibodies against interleukin (IL)-3, granulocyte macrophage (GM)-colony stimulating factor (CSF), IL-1 alpha, IL-1 beta and M-CSF. Therefore, the stimulatory activities detected in the media conditioned are due to the cytokines released in the cultures. In addition, we have also determined that addition of Naturin 2 to the cultures with LD or CD34+ cells stimulated by IL-3 and/or GM-CSF resulted in a decrease of colony formation. The inhibitory effect of Naturin 2 was mediated, at least in part, by releasing suppressive cytokines, interferon (IFN)-gamma and tumor necrosis factor (TNF)-alpha, in the 3 day--CM, since antibodies against these two suppressive cytokines partially blocked the inhibitory activity. These results demonstrate that Naturin 2 has differential effects on hematopoiesis.     

Paeonol inhibits RANKL-induced osteoclastogenesis by inhibiting ERK, p38 and NF-kappaB pathway

Numerous studies have indicated that inflammatory cytokines play a major role in osteoclastogenesis, leading to the bone resorption that is frequently associated with osteoporosis. Paeonol (2'-hydroxy-4'-methoxyacetophenone), the main active compound of the traditionally used Chinese herb Paeonia lactiflora Pallas, has anti-inflammatory activity. Here we found that paeonol markedly inhibited the receptor activator of nuclear factor kappa B ligand (RANKL) plus macrophage colony stimulating factor (M-CSF)-induced osteoclastic differentiation from bone marrow stromal cells and RAW264.7 macrophage cells. In addition, in an assay of osteoclast activity on substrate plates, paeonol significantly decreased the resorption activity of mature osteoclasts. Treatment of RAW264.7 macrophages with RANKL induced extracellular signal-regulated kinases (ERK), p38 and c-Jun N-terminal kinase (JNK) phosphorylation. However, RANKL-induced ERK, p38 but not JNK phosphorylation was attenuated by paeonol. Furthermore, RANKL-mediated increase of IkappaBalpha phosphorylation, p65 phosphorylation at Ser(536), kappaB-luciferase activity and NF-kappaB binding activity was inhibited by paeonol. In addition, paeonol also prevented the bone loss inducing by ovariectomy in vivo. Our data suggest that paeonol inhibits osteoclastogenesis from bone marrow stromal cells and macrophage cells via attenuated of RANKL-induced ERK, p38 and NF-kappaB activation, which in turn protect bone loss from ovariectomy.     

Ultrafiltered pig leukocyte extract (IMUNOR) decreases nitric oxide formation and hematopoiesis-stimulating cytokine production in lipopolysaccharide-stimulated RAW 264.7 macrophages

A low-molecular-weight (<12 kDa) ultrafiltered pig leukocyte extract, IMUNOR, was tested in experiments in vitro on non-stimulated and lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages in order to assess modulation of nitric oxide (NO) production (measured indirectly as the concentration of nitrites), hematopoiesis-stimulating activity of the supernatant of the macrophage cells (ascertained by counting cell colonies growing from progenitor cells for granulocytes and macrophages (GM-CFC) in vitro), and the release of hematopoiesis-stimulating cytokines. No hematopoiesis-stimulating activity and cytokine or NO production were found in the supernatant of non-stimulated macrophages. It was found that IMUNOR does not influence this status. Supernatant of LPS-stimulated macrophages was characterized by hematopoiesis-stimulating activity, as well as by the presence of nitrites, interleukin-6 (IL-6), and granulocyte colony-stimulating factor (G-CSF). A key role in the hematopoiesis-stimulating activity of the supernatant of LPS-stimulated macrophages could be ascribed to G-CSF since the formation of the colonies could be abrogated nearly completely by monoclonal antibodies against G-CSF. IMUNOR was found to suppress all the mentioned manifestations of the LPS-activated macrophages. When considering these results together with those from our previous in vivo study revealing stimulatory effects of IMUNOR on radiation-suppressed hematopoiesis, a hypothesis may be formulated which postulates a homeostatic role of IMUNOR, consisting in stimulation of impaired immune and hematopoietic systems but also in cutting back the production of proinflammatory mediators in cases of overstimulation which threats with undesirable consequences.     

<Emphasis Type="Italic">Vatairea macrocarpa</Emphasis> (Leguminosae) lectin activates cultured macrophages to release chemotactic mediators

The lectin from the legume Vatairea macrocarpa is a galactose/N-acetylgalactosamine binding protein that induced cellular inflammatory response mediated by resident cells. This study investigated which inflammatory mediators would be released from lectin-activated cells. The intraperitoneal injection in rats of the supernatant from cultured macrophages, but not from mast cells, stimulated with lectin induced a time- and dose-dependent release of a neutrophil chemotactic factor, termed MNCF-VML. Pharmacological modulation with dexamethasone inhibited both the lectin-induced chemotactic activity in vivo and also the lectin-induced release of MNCF-VML into the supernatant of cultured macrophages. Cyclooxygenase and lipoxygenase metabolites are apparently not involved in the action of this factor or its release, since indomethacin or MK886 were unable to affect the lectin response. The molecular weight of MNCF-VML was found to be greater than 5 kDa, which led to the investigation of which cytokine(s) could be involved by the following approaches: (a) treatment of animals with antiserum to tumor necrosis factor alpha (TNF-α), interleukin (IL)-1, or IL-8 before intraperitoneal injection of lectin and (b) addition of antiserum to TNF-α, IL-1, or IL-8 to the supernatant of lectin-stimulated macrophages before intraperitoneal administration. Antiserum to TNF-α, but not IL-1 nor IL-8, inhibited the neutrophil migration induced either by lectin or MNCF-VML. Our data suggest that neutrophil migration induced by V. macrocarpa lectin occurs via the release of cytokines such as TNF-α by macrophages. Thus, this lectin may represent an important tool to better understand pathological situations where an excess of leukocytes at inflammatory sites causes tissue injury.     

The cascade of inflammatory cytokines regulating synthesis of acute phase proteins

The acute phase cytokines: interleukin 1, tumor necrosis factor alpha (cachectin) and beta (lymphotoxin), hepatocyte stimulating factor and several interferons, all belong to the family of endotoxin-inducible, low molecular weight proteins. Their synthesis in macrophages, fibroblasts, lymphocytes, epithelial and some tumor cells is enhanced by the same cytokines, often in the autocrine manner, and suppressed by dexamethasone. The principal hepatocyte stimulating factor (HSF) regulating synthesis of acute phase proteins is probably identical with IFN-beta 2/BSF-2/IL-6, but other inflammatory cytokines (IL-1, TNF alpha, IFN-gamma) are able to induce distinct sets of acute phase proteins, or to modulate the final response pattern. The effect of hrIFN-gamma on production of acute phase proteins by human hepatoma Hep G2 cells is discussed in detail. It is concluded that the cascades of inflammatory cytokines in different tissues represent amplification and regulatory pathways controlling the development of acute phase response in vivo.     

Adoptive transfer of activated human autologous macrophages results in regression of transplanted human melanoma cells in SCID mice.

The potential anti-tumor activity of human macrophages, grown in macrophage colony stimulating factor (M-CSF), was examined in mice homozygous for the mutation severe combined immune deficiency (scid) bearing xenografts of autologous human melanoma. Injection of scid mice, bearing subcutaneous melanoma xenografts, with the cultured macrophages or with the macrophage culture supernatant, once or repeatedly, resulted in partial to complete regression of tumors. Since a large number of such macrophages (greater than 1 x 10(9)) could be grown in vitro for repeated injection, the scid-human chimera can serve as an in vivo model to examine the role of human macrophages in tumor immunity and to explore the potential of the in vitro cultured macrophages in the therapy of cancer.     

The Role of IL-17 in Joint Destruction

Interleukin-17 (IL-17) is a recently cloned cytokine secreted by activated memory CD4(+) T cells and modulates the early stage of immune responses. IL-17 stimulates epithelial, endothelial and fibroblastic stromal cells to secrete several cytokines such as IL-6, IL-8 and granulocyte colony-stimulating factor, as well as prostoglandin E2. IL-17 also stimulates the production and expression of proinflammatory cytokines, IL-1beta and tumor necrosis factor-alpha by human macrophages. IL-17 may be involved in osteoclastic bone resorption in rheumatoid arthritis patients. Recently, several groups have reported that IL-17 plays important roles in both the immune response and joint destruction in patients with rheumatoid arthritis. The control of IL-17 expression in these patients could provide directions for the development of new treatment strategies for joint destruction. (c) 2002 Prous Science. All rights reserved.     

The effects of interleukin (IL)-4 and IL-10 on macrophage growth-stimulating activities of oxidized low density lipoprotein (LDL), acetylated LDL and macrophage colony-stimulating factor: the activity of oxidized LDL is refractory to the inhibitory cytokines.

We have previously reported that ligands of scavenger receptor such as acetylated low density lipoprotein (acetyl-LDL) and oxidized LDL induced growth of peripheral macrophages in vitro. This suggests the possibility that in addition to foam cell formation, modified or oxidized LDLs induce macrophage proliferation in atherosclerotic lesions. To learn further the physiological regulation of macrophage growth, we comparatively examined the effect of interleukin (IL)-4 and IL-10 which have been reported to be suppressive to various macrophage functions on macrophage growth-stimulating activities of the acetyl-LDL, oxidized LDL and macrophage colony-stimulating factor (M-CSF). An in vitro study showed that the activity of M-CSF-containing L-cell-conditioned medium was the most sensitive to the suppressive effects of these cytokines. The growth-inducing activity of acetyl-LDL was significantly inhibited by both IL-4 and IL-10. On the other hand, the activity of oxidized LDL was not attenuated by IL-4 or IL-10. These data indicate that macrophage growth-stimulating activity of oxidized LDL, in contrast to that of M-CSF or acetyl-LDL, is refractory to these suppressive cytokines. Oxidized LDL may act as a potent macrophage growth-stimulating factor in atherosclerotic or other inflammatory sites, even when these cytokines are produced by inflammatory and immunological reactions in situ.     

Macrophage Colony-Stimulating Factor in the Pathogenesis of HIV Infection: Potential Target for Therapeutic Intervention

Macrophage colony stimulating factor (M-CSF) appears to play a major role in promoting and maintaining reservoirs of human immunodeficiency virus type 1 (HIV-1) in infected individuals. HIV-1 infection induces production of M-CSF by macrophages, which in turn promotes further infection of macrophages via increases in CD4 and CCR5 receptors, as well as increases in virus gene expression. M-CSF promotes the ontogeny and survival of macrophages, contributing to both the number and longevity of these infected cells. M-CSF dysregulation promotes the differentiation of monocytes toward macrophages and osteoclasts and at the same time may inhibit differentiation toward dendritic cells, resulting in immune impairment. The potential role of M-CSF in HIV-associated end organ diseases including HIV-associated dementia, HIV-associated nephropathy, and osteoporosis is discussed. This review emphasizes the need for developing M-CSF antagonists for treatment of HIV-1-infected patients.     

Suppression of polyclonal immunoglobulin production by a soluble factor produced by a human thymus hybridoma

A human thymus cell hybridoma was established using thymus cells obtained from a patient with common variable hypogammaglobulinemia and associated thymoma. This hybridoma secreted a suppressor factor for polyclonal antibody synthesis. Supernatants of this hybrid showed 40-80% suppression of both IgM and IgG synthesis by pokeweed mitogen-stimulated human peripheral blood lymphocytes. Hybridoma supernatants were suppressive for immunoglobulin production only if added within the initial 48 h of the seven-day culture period. Suppression of antibody production by the hybridoma supernatant was prevented by preabsorption with T lymphocytes. Further, the suppressor factor was shown to inhibit antibody production in reconstructed cultures containing T4+ cells and B cells, yet the suppression could be abrogated by increasing the number of T4+ cells. The hybrid supernatant had no affect on the proliferation of human mononuclear cells in response to pokeweed mitogen, lipopolysaccharide, concanavalin A or alloantigen but inhibited phytohemagglutinin-induced proliferation. The target cell population for the inhibition of phytohemagglutinin responsiveness was shown to be a T4+ lymphocyte (helper inducer T cell). These results suggest that thymus hybridoma cells can produce immunoregulatory products that act through the modulation of T4+ lymphocyte function. To our knowledge this is the first human thymus cell hybridoma to be reported. Studies on such cell lines may provide important information on immunoregulatory thymic factors.     

Role of mitogen-activated protein kinase family in serum-induced leukaemia inhibitory factor and interleukin-6 secretion by bone marrow stromal cells

1: In the haematopoietic microenvironment, bone marrow stromal cells play an important role in regulating haematopoiesis by expressing various cytokines, including leukaemia inhibitory factor (LIF) and interleukin-6 (IL-6). However, the intracellular signal that regulates cytokine secretion in bone marrow stromal cells has not been determined. The aim of this study was to evaluate the role of mitogen-activated protein kinase (MAPK) family in serum-induced secretion of LIF and IL-6 by bone marrow stromal cells. 2: Transformed human bone marrow stromal cells (HS-5) were stimulated with foetal calf serum (FCS) to produce LIF and IL-6. FCS also induced activation of extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun NH(2)-terminal kinase (JNK). 3: Both PD98059 (MAPK/ERK kinase inhibitor) and SB203580 (p38 MAPK inhibitor) attenuated FCS-induced LIF protein production and gene expression. SB203580 decreased IL-6 production and gene expression, but PD98059 had no effect on IL-6 production and gene expression. 4: Expression of a dominant-negative mutant form of JNK1 that blocked FCS-induced JNK activity had no effect on protein production and gene expression of these cytokines. 5: These findings demonstrate that both ERK and p38 MAPK are involved in FCS-induced LIF secretion, whereas only p38 MAPK is important for IL-6 secretion, and that FCS-induced activation of JNK has no effect on the production of LIF and IL-6. We conclude that, in spite of their similar biological effects, they are differentially regulated at the level of MAPK activity in bone marrow stromal cells.     

Cytokine/anti-cytokine therapy – novel treatments for asthma?

Asthma is a chronic inflammatory disease of the airways and there are no preventions or cures. Inflammatory cells through the secretion of cytokines and pro-inflammatory molecules are thought to play a critical role in pathogenesis. Type 2 CD4(+) lymphocytes (Th2 cells) and their cytokines predominate in mild to moderate allergic asthma, whereas severe steroid-resistant asthma has more of a mixed Th2/Th1 phenotype with a Th17 component. Other immune cells, particularly neutrophils, macrophages and dendritic cells, as well structural cells such as epithelial and airway smooth muscle cells also produce disease-associated cytokines in asthma. Increased levels of these immune cells and cytokines have been identified in clinical samples and their potential role in disease demonstrated in studies using mouse models of asthma. Clinical trials with inhibitors of cytokines such as interleukin (IL)-4, -5 and tumour necrosis factor-α have had success in some studies but not others. This may reflect the design of the clinical trials, including treatments regimes and the patient population included in these studies. IL-13, -9 and granulocyte-macrophage colony-stimulating factor are currently being evaluated in clinical trials or preclinically and the outcome of these studies is eagerly awaited. Roles for IL-25, -33, thymic stromal lymphopoietin, interferon-γ, IL-17 and -27 in the regulation of asthma are just emerging, identifying new ways to treat inflammation. Careful interpretation of results from mouse studies will inform the development and application of therapeutic approaches for asthma. The most effective approaches may be combination therapies that suppress multiple cytokines and a range of redundant and disconnected pathways that separately contribute to asthma pathogenesis. Astute application of these approaches may eventually lead to the development of effective asthma therapeutics. Here we review the current state of knowledge in the field.     

Melatonin antagonises the cyclosporine A immunosuppressive effects in rat thymuses

Cyclosporine A (CsA) is a powerful immunosuppressant inducing marked involution of the thymus with disappearance of interdigitating cells (IDCs) and reducing the number of macrophages (Mphi). Melatonin (Mel) is a potent antioxidant agent that could be useful in attempting to reduce CsA toxicity. Moreover, Mel has been found to exert positive influence on lymphocytes, spleen and thymus. In this study, we evaluated the effects of Mel on the thymic involution induced by CsA. CsA caused profound changes in thymic cytoarchitecture, i.e. the complete disappearance of thymic medulla and reduced the number of acid phosphatase positive macrophages. There was no difference between thymic morphology of Mel-treated rats and the control animals injected only with olive oil. The simultaneous Mel-CsA administration prevented the involution of the thymic medulla and the reduction of the number of macrophages. These findings suggested that Mel probably antagonized the immunosuppressive CsA effects.