A variety of cytokines and immunologically relevant surface molecules are expressed by normal human skeletal muscle cells under proinflammatory stimuli

Muscle is an attractive target for gene therapy and for immunization with DNA vaccines and is also the target of immunological injury in myositis. It is important therefore to understand the immunologic capabilities of muscle cells themselves. In this study, we show that proinflammatory stimuli induce the expression of other cytokines such as IL-6, transforming growth factor-beta (TGF-β), and granulocyte-macrophage colony-stimulating factor (GM-CSF) by muscle cells themselves, as well as the up-regulation of human leucocyte antigen (HLA) class I, class II and intercellular adhesion molecule-1 (ICAM-1). Thus, muscle cells have an inherent ability to express and respond to a variety of cytokines and chemokines. The levels of HLA class I, class II and ICAM-1 in inflamed muscle may be affected by the secreted products of the stimulation.     

Novel aspects on the contribution of T cells and dendritic cells in the pathogenesis of myositis

This review focuses on recent advances and new hypothesis in the understanding of the T and dendritic cells contribution to the pathogenesis of idiopathic inflammatory myopathies (IIMs), especially polymyositis (PM) and dermatomyositis (DM). The new data show that non-specific amplification of muscle inflammation by T lymphocyte and dendritic cells may result from the local production of cytokines and chemokines. Synergistic interactions between these factors explain some of the clinical features. The potent role of these molecules suggests their potential for therapeutic manipulation using specific inhibitors.     

Secretion of cytokines and chemokines by polarized human epithelial cells from the female reproductive tract

BACKGROUND: Pro-inflammatory chemokines that attract and cytokines that activate immune cells contribute to normal physiological homeostasis in the female reproductive tract, and are needed to deal effectively with potential pathogenic microbes. Mucosal epithelial cells are capable of producing these factors that communicate with cells of the innate and adaptive immune systems. METHODS: Epithelial cells from Fallopian tube, endometrium and endocervix were isolated and grown to high transepithelial resistance in cell inserts from seven patients who had hysterectomies. Interleukin (IL)-8, IL-6, granulocyte colony-stimulating factor (G-CSF), monocyte chemoattractant protein-1 (MCP-1), granulocyte-macrophage colony-stimulating factor (GM-CSF), tumour necrosis factor-alpha (TNF-alpha) and macrophage inflammatory peptide-1beta (MIP-1beta) were assessed by Luminex bead analysis or enzyme-linked immunosorbent assay (ELISA) in epithelial cell conditioned media from the apical and basolateral compartments. RESULTS: With the exception of MCP-1, the seven chemokines/cytokines constitutively produced by the polarized epithelial cells were preferentially secreted apically. A concentration pattern was found in all cases, with IL-8 and IL-6 produced in the greatest quantity. CONCLUSIONS: The concentrations of IL-8, IL-6, G-CSF and MCP-1 are similar to the levels found in reproductive tract fluids of patients with infection. The constitutive secretion and compartmentalization of large quantities of bioactive chemokines and cytokines provide additional evidence for the role of epithelial cells as gatekeepers of innate immune protection in the female reproductive tract.     

Doxycycline alters the expression of inflammatory and immune-related cytokines and chemokines in human endometrial cells: implication in irregular uterine bleeding

BACKGROUND: Increased production of pro-inflammatory mediators is considered central in the manifestation of events leading to irregular uterine bleeding in progestin-only contraceptive users. Evidence suggests that in addition to its antimicrobial property, doxycycline (Dox) acts as an anti-inflammatory agent mainly through the suppression of pro-inflammatory mediators. METHODS: We tested this hypothesis in the endometrial environment using an in vitro model consisting of isolated human endometrial glandular epithelial and stromal cells and a human endometrial surface (HES) epithelial cell line cultured under defined conditions. RESULTS: We found that Dox at doses ranging from 1 to 100 microg/ml had a limited growth-inhibitory effect on these cells, whereas Dox in a dose-dependent manner inhibited the production of tumour necrosis factor-alpha (TNF-alpha). Using multiplex cytokine/chemokine protein analysis to test a broader range of Dox activity, we found that Dox at 25 microg/ml either alone or in the presence of 17beta-estradiol (E2), medroxyprogesterone acetate (MPA) and E2+MPA (10(-8) M) as well as TNF-alpha (25 ng/ml), representing the endometrial environment exposed to contraceptives as well as inflammatory conditions, respectively, altered the production of multiple cytokines and chemokines as compared with untreated controls. These actions of Dox occurred in cell-, ovarian steroid- and cytokine/chemokine-dependent manners. Although Dox reduced the regulatory action of steroids on the production of these cytokines/chemokines, it was less effective on TNF-alpha-treated cells. CONCLUSIONS: The results support the hypothesis that Dox, by modulating the endometrial expression of multiple inflammatory-related cytokines/chemokines in a cell- and cytokine/chemokine-dependent manner, may have a therapeutic potential in patients experiencing irregular uterine bleeding, in particular in progestin-dominant contraceptive users.     

Immunomodulatory properties of human serum immunoglobulin A: anti-inflammatory and pro-inflammatory activities in human monocytes and peripheral blood mononuclear cells

Our study investigated the immunomodulatory activities of human plasma-derived serum immunoglobulin (Ig)A. Previous findings seem contradictory indicating either pro- or anti-inflammatory activities. We used serum IgA purified from large plasma pools and studied the modulation of the release of cytokines and chemokines from resting and lipopolysaccharide (LPS, endotoxin)-stimulated human adherent monocytes and human peripheral blood mononuclear cells (PBMC). Our results indicate that IgA down-modulates the release of the pro-inflammatory chemokines monocyte chemoattractant protein (MCP) 1, macrophage inflammatory protein (MIP) 1alpha and MIP1beta from LPS-stimulated PBMC and the release of MCP1, MIP1alpha and MIP1beta from LPS-stimulated monocytes. Furthermore, we confirmed previous reports that plasma-derived serum IgA down-modulates the release of the pro-inflammatory cytokines, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha, from LPS-stimulated monocytes and PBMC, and up-regulates the release of IL-1 receptor antagonist (IL-1RA) from resting and LPS-stimulated monocytes and resting PBMC. This IgA-mediated up-regulation of IL-1RA is independent of the simultaneous up-regulation of IL-1beta release, as shown by blocking the biological activity of IL-1beta with a neutralizing antibody. On the other hand, we also found an IgA-induced pro-inflammatory activity, namely IgA-mediated up-regulation of the release of pro-inflammatory IL-1beta as well as down-regulation of the anti-inflammatory cytokines IL-10 and IL-12p40 from LPS-stimulated monocytes and PBMC and a down-regulation of transforming growth factor (TGF)-beta from resting and LPS-stimulated PBMC. We conclude that human serum IgA has both an anti-inflammatory and a pro-inflammatory capacity and this dual capacity might contribute to the feedback mechanisms maintaining a balance between pro-inflammatory and anti-inflammatory activities.     

Cytokines: the yin and yang of vitiligo pathogenesis

Introduction: Dysregulation of melanocyte function is associated with vitiligo, an idiopathic autoimmune hypopigmentary skin disorder, caused by the selective destruction of melanocytes. Cytokines, the key mediators of immune response, which are pivotal in maintaining immune homeostasis, are crucial in vitiligo pathogenesis. Several studies indicate that there is an imbalance between pro- and anti-inflammatory cytokines in the skin and serum of vitiligo patients.

Areas covered: In this comprehensive review, we have summarized the correlation of cytokine imbalance and vitiligo pathogenesis, its role in melanocyte biology, and its impact on vitiligo treatment. We have integrated various published reports on the levels of major cytokines from skin and serum samples of vitiligo patients. We have also discussed the role of endoplasmic reticulum and oxidative stress on cytokine imbalance and vice versa leading to destruction of melanocytes.

Expert commentary: The review reflects that dysregulation of cytokines is multifactorial, ranging from genetic predisposition to altered protein expression relevant to vitiligo pathogenesis. We emphasize that cytokine imbalance in systemic and skin microenvironment plays a crucial role in vitiligo pathogenesis and has promising potential as therapeutic targets for vitiligo.     

Interaction between chronically HIV-infected promonocytic cells and human umbilical vein endothelial cells: role of proinflammatory cytokines and chemokines in viral expression modulation

HIV type 1 expression was significantly up-regulated in chronically infected promonocytic cell line (U1) co-cultured with human umbilical vein endothelial cells (HUVEC). Virus replication, evaluated as supernatant p24 release, was higher when U1 were co-cultured with IL-1β-activated HUVEC than with unstimulated HUVEC. When non-adherent U1 were removed from co-cultures, the remaining U1 cells adherent to the endothelial monolayer still showed enhanced HIV replication in comparison with an equal number of U1 cultured alone. While addition of adhesion molecule blocking antibodies (anti-intercellular adhesion molecule-1 (ICAM-1), -vascular cell adhesion molecule-1 (VCAM-1), -CD18 and -very late antigen-4 (VLA-4)) strongly inhibited adherence of U1 cells to endothelial monolayers, such treatment resulted in only a partial reduction in p24 release. Furthermore, HIV replication in U1 cells was enhanced on culture in HUVEC-conditioned media. Such data suggest that soluble mediators secreted by endothelial monolayers may modulate HIV-1 expression. Indeed, addition of cytokine and chemokine antagonists to both U1/HUVEC co-cultures and to U1 cultured in HUVEC-conditioned media clearly down-regulated p24 release. Anti-IL-6, anti-tumour necrosis factor-alpha (TNF-α) and, particularly, anti-MCP-1 MoAbs reduced p24 release, while anti-IL-8 polyclonal antiserum and IL-1 receptor antagonist (IL-1Ra) had no significant effect. Thus, the interaction between HUVEC and infected monocytic cells up-regulates HIV-1 replication predominantly through production of endothelium-derived soluble factors including MCP-1, TNF-α and IL-6. This phenomenon may influence the passage of HIV-1 from latency to productive replication and enhance virus spreading during physiological and/or pathological contact of monocytes with endothelium.     

Expression and modulation of IFN-gamma-inducible chemokines (IP-10, Mig, and I-TAC) in human brain endothelium and astrocytes: possible relevance for the immune invasion of the central nervous system and the pathogenesis of multiple sclerosis.

Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS) mediated by blood-derived immune cells invading the CNS. This invasion could be determined by chemokines, and their role within the MS-affected brain is still poorly defined. We investigated the expression by RT-PCR and protein release by ELISA of the interferon-gamma (IFN-gamma)-inducible chemokines in human brain microvascular endothelial cells (HBMECs) and astrocytes. The monokine induced by IFN-gamma (Mig) behaves as a homing chemokine constitutively expressed in HBMECs and astrocytes, whereas the IFN-gamma-inducible 10-kDa protein (IP-10) and IFN-inducible T cell alpha-chemoattractant (I-TAC) are induced only after inflammatory stimuli. The biologic activity of IFN-gamma-inducible chemokines from an endothelial source was analyzed, and the transendothelial migration of activated lymphocytes was partly antagonized by specific antibodies, especially anti-Mig antibody. Our data highlight the capability of cells of the CNS to activate the chemoattractant machinery in a proinflammatory environment and in MS.     

Bresol inhibits phosphodiesterase 4 gene expression and modulates the levels of select mediators of inflammation in human monocytic cells

Bresol–a poly-herbal formulation, has been reported to be effective against bronchial asthma and allergic rhinitis in children. In vivo studies have supported the anti-histaminic and anti-anaphylactic action of bresol. However, the mechanism of action of bresol in modulation of inflammation has not been studied at the cellular and molecular level. The present study was aimed to elucidate the mechanism(s) of action of bresol at the cellular and molecular levels, using human monocyte leukemia cells. The effects of bresol on phosphodiesterase 4B (PDE4B) gene expression were analyzed using human monocytic U937 leukemia cells. The ability of bresol to stimulate cAMP formation in these cells, as well as its effects on mediators of inflammation like tumor necrosis factor-α (TNFα), nitric oxide (NO), and cycloxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated U937 cells, were also studied. The results here indicated that bresol exhibited potential anti-inflammatory properties by inhibiting LPS-induced PDE4B gene expression in the cells. Bresol also dose dependently activated cAMP formation, and inhibited TNFα, NO, as well as COX-2 formation in the LPS-stimulated cells. Based upon the results, we concluded that the reported anti-inflammatory activity of bresol might be attributed to its abilities to inhibit PDE4B and thus elevate cAMP levels in human monocytes. The anti-inflammatory effects of bresol might also be a result of the capacity of bresol to modulate the formation of TNFα, NO, and COX-2 in monocytes.     

代偿性酸中毒、炎性反应和病因是影响急性肾损伤预后的重要因素

目的分析影响急性贤损伤(AKI)预后的因素,评判不同病因对预后的影响。方法回顾性分析507例AKI病例,分为预后良好组和预后不良组,收集临床资料,根据治疗前后SCr变化,分析AKI预后的危险因素和病因对预后的影响。结果预后良好组253例(49.9%),预后不良组254例(50.1%)。预后不良组年龄较大(P0.001),SCr基线值较高(P0.01),贫血和低白蛋白血症的发生率较高(P0.01和P0.001),炎性指标更高(P0.001)。通过Logistic回归分析建立预后模型,分析结果显示,即使代谢性酸中毒处于HCO3-降低而p H值正常的阶段,仍是影响预后的危险因素(P0.05),MODS(P0.001)、炎性因子(P0.01)和少尿(P0.01)也是影响预后的危险因素;血白蛋白(P0.01)和血红蛋白(P0.05)是预后的保护性因素。本研究中,AKIN 1、2期中最常见病因为重症感染导致的AKI,AKIN 3期中最常见小管间质损害,不同分期对预后的影响无显著差别。结论 1)代偿性酸中毒、MODS、炎性反应和少尿是AKI预后的危险因素;2)需重视病因对AKI临床结局的影响。     

Oestrogen receptor β is expressed in adult human skeletal muscle both at the mRNA and protein level

Aim: There are two known oestrogen receptors (ER), oestrogen receptor α (ERα) and the recently cloned oestrogen receptor β (ERβ). ERα mRNA has been detected in mouse, rat, bovine and human skeletal muscle. ERβ mRNA has been detected in bovine skeletal muscle. To our knowledge, no study has investigated the expression of oestrogen receptor β in human skeletal muscle. Therefore, the primary aim of the present investigation was to study ERβ mRNA and protein expression in human skeletal muscle. In addition the ERα expression was also studied. Methods: Muscle biopsies were taken from vastus lateralis in six healthy adults (three women and three men). mRNA expression was detected with real‐time PCR (TaqMan) and protein localization by immunohistochemistry. Results: A clear expression of ERα and ERβ mRNA was seen in skeletal muscle in all subjects. The ERα mRNA expression was 180 fold higher compared with that of ERβ mRNA. Immunohistochemistry demonstrated positive staining for ERβ, but not for ERα, with localization to the nuclei of skeletal muscle fibres. On average, 70% of all nuclei were ERβ‐positive. Conclusion: The present study shows for the first time ERβ mRNA and protein expression in human skeletal muscle tissue in both males and females.     

Transplantation and inflammation: implications for the modification of chemokine function

Oxidative stress is a major and recurring cause of damage during inflammation, especially following organ transplantation. Initial ischaemia–reperfusion injury causes the production of many reactive oxygen and nitrogen species, and subsequent recruitment and activation of inflammatory cells can lead to further oxidative stress. This stress is well known to cause damage at the cellular level, for example by induction of senescence leading to the production of a characteristic senescence‐associated secretory phenotype. Chemokines are an important component of the senescence‐associated secretory phenotype, recruiting further leucocytes and reinforcing the stress and senescence responses. As well as inducing the production of proteins, including chemokines, oxidative stress can alter proteins themselves, both directly and by induction of enzymes capable of modification. These alterations can lead to important modifications to their biological activity and also alter detection by some antibodies, potentially limiting the biological relevance of some immunochemical and proteomic biomarkers. Peroxynitrite, a reactive nitrogen species generated during inflammation and ischaemia, can cause such modifications by nitrating chemokines. Matrix metalloproteinases, released by many stressed cells, can cleave chemokines, altering function, while peptidylarginine deiminases can inactivate certain chemokines by citrullination. This review discusses the relationship between inflammation and post‐translational modification, focusing on the functional modulation of transplant‐relevant pro‐inflammatory chemokines.     

The role of T-regulatory cells and Toll-like receptors in the pathogenesis of human inflammatory bowel disease

Two related chronic inflammatory diseases, Crohn's disease and ulcerative colitis, are together often referred to as inflammatory bowel disease (IBD). Current treatment options are not curative, and patients face lifelong therapy and debilitation. IBD is thought to be the product of a combination of genetic and environmental factors that result in the abnormal regulation of immune responses. Experimental models have demonstrated that normal CD4+ T-regulatory (Treg) cell responses and commensal bacteria are required for the maintenance of gut immune homeostasis. Recent evidence that CD4+ T cells express Toll-like receptors (TLRs) and respond directly to TLR ligands, suggests that signals from commensal bacteria may directly affect T-cell responses in the gut. In this review, we focus on evidence that defects in Treg cells may underlie IBD in humans. In addition, we discuss evidence that direct signaling via TLRs to T cells can affect IBD and that T-cell-dependent responses to bacterial proteins, such as flagellin, are central to the aetiology of this disease.     

CD137 (ILA/4-1BB), expressed by primary human monocytes, induces monocyte activation and apoptosis of B lymphocytes

Human CD137 is a member of the tumor necrosis factor (TNF) receptor family and the homologue of murine 4-1BB. Recent studies have demonstrated that CD137 promotes accessory T cell activation, and regulates proliferation and survival of T lymphocytes. This study reports on the expression and function of CD137 in peripheral blood monocytes. While monocytes showed constitutive expression in 10 out of 18 healthy donors, CD137 was not expressed on resting T or B lymphocytes. Immobilized antibodies to CD137 markedly induced the production of IL-8 and TNF-alpha protein and mRNA, and led to inhibition of IL-10 expression by primary monocytes. Furthermore, cross-linking of CD137 on monocytes resulted in an increase of B lymphocyte apoptosis mediated by direct cell-cell contact of both cell populations. In conclusion, this study identified CD137 as a new receptor involved in monocyte activation by inducing a characteristic cytokine release profile. In addition, CD137 may play a role in monocyte-dependent control of B lymphocyte survival.     

Autocrine and immune cell‐derived BDNF in human skeletal muscle: implications for myogenesis and tissue regeneration

The neurotrophin system has a role in skeletal muscle biology. Conditional depletion of BDNF in mouse muscle precursor cells alters myogenesis and regeneration in vivo. However, the expression, localization and function of BDNF in human skeletal muscle tissue is not known, so the relevance of the rodent findings for human muscle are unknown. Here we address this by combining ex vivo histological investigations on human biopsies with in vitro analyses of human primary myocytes. We found that BDNF was expressed by precursor and differentiated cells both in vitro and in vivo. Differential analysis of BDNF receptors showed expression of p75NTR and not of TrkB in myocytes, suggesting that the BDNF–p75NTR axis is predominant in human skeletal muscle cells. Several in vitro functional experiments demonstrated that BDNF gene silencing or protein blockade in myoblast cultures hampered myogenesis. Finally, histological investigations of inflammatory myopathy biopsies revealed that infiltrating immune cells localized preferentially near p75NTR‐positive regenerating fibres and that they produced BDNF. In conclusion, BDNF is an autocrine factor for skeletal muscle cells and may regulate human myogenesis. Furthermore, the preferential localization of BDNF‐producing immune cells near p75NTR‐positive regenerating myofibres suggests that immune cell‐derived BDNF may sustain tissue repair in inflamed muscle. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Interleukin-31 induces cytokine and chemokine production from human bronchial epithelial cells through activation of mitogen-activated protein kinase signalling pathways: implications for the allergic response

Interleukin-31 (IL-31) is a novel T-helper-lymphocyte-derived cytokine that plays an important role in allergic skin inflammation and atopic dermatitis. It has recently been implicated in bronchial inflammation. We investigated the functions and mechanisms of IL-31-induced activation of human bronchial epithelial cells. The gene and protein expressions of candidate cytokines/chemokines from IL-31-stimulated human bronchial epithelial BEAS-2B cells were first quantified by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activity of different mitogen-activated protein kinases (MAPKs) in IL-31-stimulated BEAS-2B cells was assessed by Western blot. The IL-31 could significantly elevate the gene and protein expressions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) of BEAS-2B cells in both time-dependently and dose-dependently. Combination of IL-31 with either IL-4 or IL-13 further enhanced VEGF and CCL2 production while IL-31 could synergistically augment the release of EGF, VEGF, CCL2, IL-6 and IL-8 in cocultures of BEAS-2B cells and eosinophils. In addition, IL-31 could activate p38 MAPK, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) of BEAS-2B cells. Selective inhibitors of p38 MAPK (SB203580), ERK (PD98059), and JNK (SP600125) could differentially inhibit the production of EGF, VEGF and CCL2, thereby suggesting a role for MAPKs in IL-31 functions. In conclusion, the activation of MAPKs can be crucial for IL-31-mediated activation of bronchial epithelial cells, thereby providing an immunological role for IL-31 in bronchial inflammation, at least partly, via epithelial EGF, VEGF and CCL2 production.