多发性骨髓瘤与白细胞介素-6

白细胞介素-6是多发性骨髓瘤(multiple myeloma,MM)瘤细胞生长和生存的关键因子,也是MM患者发病的主要因子。IL-6/IL-6R系统通过不同通路影响多发性骨髓瘤瘤细胞生长并导致患者骨损害、类风湿性关节炎等一系列并发症。针对IL-6/IL-6R系统的治疗方法将给MM的治疗带来重大的进展。     

The family of the IL-6-Type cytokines: Specificity and promiscuity of the receptor complexes

The cytokines IL-6, LIF, CNTF, OSM, IL-11, and CT-1 have been grouped into the family of IL-6-type cytokines, since they all require gp130 for signal transduction. Interestingly, gp130 binds directly to OSM, whereas complex formation with the other cytokines depends on additional receptor subunits. Only limited structural information on these cytokines and their receptors is available. X-ray structures have been solved for the cytokines LIF and CNTF, whose up-up-down-down four-helix bundle is common to all of these cytokines, and for the receptors of hGH and prolactin, which contain two domains with a fibronectin III-like fold. Since cocrystallization and x-ray analysis of the up to four different proteins forming the receptor complexes of the IL-6-type cytokines is unlikely to be achieved in the near future, model building based on the existing structural information is the only approach for the time being. Here we present model structures of the complexes of human and murine IL-6 with their receptors. Their validity can be deduced from the fact that published mutagenesis data and the different receptor specificity of human and murine IL-6 can be understood. It is now possible to predict the relative positions and contacts for all molecules in their respective complexes. Such information can be used for the rational design of cytokine and receptor antagonists, which may have a valuable therapeutic perspective. Proteins 27:96–109 © 1997 Wiley-Liss, Inc.     

Maximal T cell IL-13 production requires monocyte or monokine participation

The T cell-secreted lymphokine interleukin 13 (IL-13) exerts pleiotropic effects on monocytes (Mphi) and B cells. Since accessory cells, like Mphi and B cells, also act in antigen-presenting and lymphokine augmentation of T cells, Mphi and B cells may be able to effect T cell IL-13 production. Purified T cells produced slightly less IL-13 than the lower T cell numbers contained in peripheral blood mononuclear cell population, further suggesting accessory cell augmentation. Addition of 10% B cells [either unstimulated or pokeweed mitogen (PWM)-stimulated] to autologous T cells only moderately augmented T cell IL-13 levels. PWM-stimulated B cell culture supernates had even less augmenting effect on T cell IL-13 levels and unstimulated B cell culture supernates did not augment T cell IL-13 production. In contrast to the moderately augmenting effect of B cells or their stimulated culture supernates, addition of 10% Mphi, either unstimulated or muramyl dipeptide (MDP)+IFN-gamma stimulated, to autologous T cells produced a highly significant increase in T cell IL-13 production. Mphi culture supernates were equally effective in augmenting T cell IL-13 levels, suggesting both that cell-to-cell contact is not critical for Mphi augmentation of T cell IL-13 levels, and that Mphi secreted factors are pivotal. CD64(+) Mphi (or their culture supernates), which are known as poor antigen-presenting cells, also effectively augmented T cell IL-13 production, further supporting the involvement of Mphi secreted factors. Finally, experiments with exogenous addition of recombinant monokines, as well as neutralization experiments with different cytokine antibodies, suggested IL-1beta as a primary cytokine involved in the augmentation of T cell IL-13 levels by accessory cells. However, these experiments also indicated other unidentified Mphi factors as playing a significant role in producing maximal T cell IL-13 production.     

IL-6 and its role in IgA nephropathy development

IL-6 is considered one of the well characterized cytokines exhibiting homeostatic, pro- and anti-inflammatory activities, depending on the receptor variant and the induced intracellular cis- or trans-signaling responses. IL-6-activated pathways are involved in the regulation of cell proliferation, survival, differentiation, and cell metabolism changes.Deviations in IL-6 levels or abnormal response to IL-6 signaling are associated with several autoimmune diseases including IgA nephropathy (IgAN), one of most frequent primary glomerulonephritis worldwide. IgAN is associated with increased plasma concentration of IL-6 and increased plasma concentration of aberrantly galactosylated IgA1 immunoglobulin (Gd-IgA1). Gd-IgA1 is specifically recognized by autoantibodies, leading to the formation of circulating immune complexes (CIC) with nephritogenic potential, since CIC deposited in the glomerular mesangium induce mesangial cells proliferation and glomerular injury. Infection of the upper respiratory or digestive tract enhances IL-6 production and in IgAN patients is often followed by the macroscopic hematuria.This review recapitulates general aspects of IL-6 signaling and summarizes experimental evidences about IL-6 involvement in the etiopathogenesis of IgA nephropathy through the production of Gd-IgA1 and regulation of mesangial cell proliferation.     

Tryptophan (W) at position 37 of murine IL-12/IL-23 p40 is mandatory for binding to IL-12Rβ1 and subsequent signal transduction

Interleukin (IL)-12 and IL-23 are composite cytokines consisting of p35/p40 and p19/p40, respectively, which signal via the common IL-12 receptor β1 (IL-12Rβ1) and the cytokine-specific receptors IL-12Rβ2 and IL-23R. Previous data showed that the p40 component interacts with IL-12Rβ1, whereas p19 and p35 subunits solely bind to IL-23R and IL-12Rβ2, resulting in tetrameric signaling complexes. In the absence of p19 and p35, p40 forms homodimers and may induce signaling via IL-12Rβ1 homodimers. The critical amino acids of p19 and p35 required for binding to IL-23R and IL-12Rβ2 are known, and two regions of p40 critical for binding to IL-12Rβ1 have recently been identified. In order to characterize the involvement of the N-terminal region of p40 in binding to IL-12Rβ1, we generated deletion variants of the p40-p19 fusion cytokine. We found that an N-terminal deletion variant missing amino acids M23 to P39 failed to induce IL-23-dependent signaling and did not bind to IL-12Rβ1, whereas binding to IL-23R was maintained. Amino acid replacements showed that p40W37K largely abolished IL-23-induced signal transduction and binding to IL-12Rβ1, but not binding to IL-23R. Combining p40W37K with D36K and T38K mutations eliminated the biological activity of IL-23. Finally, homodimeric p40D36K/W37K/T38K did not interact with IL-12Rβ1, indicating binding of homodimeric p40 to IL-12Rβ1 is comparable to the interaction of IL-23/IL-12 and IL-12Rβ1. In summary, we have defined D36, W37, and T38 as hotspot amino acids for the interaction of IL-12/IL-23 p40 with IL-12Rβ1. Structural insights into cytokine–cytokine receptor binding are important to develop novel therapeutic strategies.     

The vanilloid capsaicin induces IL-6 secretion in prostate PC-3 cancer cells

Capsaicin (8-methyl-N-vanillyl-6-nonenamide), a constituent of green and red peppers, has been linked with suppression of tumorigenesis through a mechanism that is not well understood. In the present study, we examined the effects of capsaicin on the production of the cytokine interleukin (IL)-6 by PC-3 cells at both protein and mRNA levels which were evaluated by ELISA and real-time PCR, respectively. Capsaicin-treated PC-3 cells increased the synthesis and secretion of IL-6 which was abrogated by the transient receptor potential vanilloid receptor subtype 1 (TRPV1) antagonist capsazepine, as well as by inhibitors of PKC-α, phosphoinositol-3 phosphate kinase (PI-3K), Akt and extracellular signal-regulated protein kinase (ERK). We analyzed the role of capsaicin in the tumor necrosis factor (TNF)-α secretion by PC-3 cells which was increased at shorter times than IL-6 production. Furthermore, incubation of PC-3 cells with an anti-TNF-α antibody blocked the capsaicin-induced IL-6 secretion. These results raise the possibility that capsaicin-mediated IL-6 increase in prostate cancer PC-3 cells is regulated at least in part by TNF-α secretion and signaling pathway involving Akt, ERK and PKC-α activation.     

Biology of IL-27 and its Role in the Host Immunity against Mycobacterium Tuberculosis

IL-27, a heterodimeric cytokine of IL-12 family, regulates both innate and adaptive immunity largely via Jak-Stat signaling. IL-27 can induce IFN-γ and inflammatory mediators from T lymphocytes and innate immune cells. IL-27 has unique anti-inflammatory properties via both Tr1 cells dependent and independent mechanisms. Here the role and biology of IL-27 in innate and adaptive immunity are summarized, with special interest with immunity against Mycobacterium tuberculosis.     

Synthesis of andrographolide derivatives and their TNF-alpha and IL-6 expression inhibitory activities

The synthesis of a series of andrographolide derivatives was described and their inhibitory effects on TNF-α and IL-6 secretion in mouse macrophages were also evaluated. Most of the tested compounds showed inhibitory effects, and the compounds with the structure of 12-hydroxy-14-dehydroandrographolide showed better inhibitory activity than the compounds with the structure of isoandrographolide.     

Association of Polymorphisms in the Interleukin 6 Receptor Complex with Obesity and Hyperandrogenism

Objective: Interleukin‐6 (IL‐6), is an inflammatory cytokine that may influence the pathogenesis of obesity and hyperandrogenism. IL‐6 exerts its actions through a heterodimeric receptor consisting of two membrane‐bound glycoproteins: an 80‐kDa IL‐6 binding unit (IL6R‐α) and a 130‐kDa IL‐6 signal transducer (gp130). Genetic variability at these loci might contribute to explain the development of obesity and hyperandrogenism. Research Methods and Procedures: We have evaluated the possible association of several polymorphisms in the IL6R‐α and gp130 genes with obesity and/or hyperandrogenism in a case‐control study involving 143 hyperandrogenic patients and 45 healthy women from Spain. Results: A microsatellite CA‐repeat polymorphism in the IL6R‐α locus was associated with obesity. The frequency of the common 149‐bp allele was markedly increased in obese women compared with controls when considering patients and controls as a whole (0.41 vs. 0.29, χ² = 17.085, p < 0.050). On the other hand, the uncommon Arg148 allele of the Gly148Arg polymorphism in the gp130 gene was more frequent in controls compared with hyperandrogenic patients (0.17 vs. 0.08, χ² = 5.605, p = 0.026). Controls carrying Arg148 alleles had lower 11‐deoxycortisol and 17‐hydroxyprogesterone concentrations, a lower response of androstenedione to 1–24 adrenocorticotropin, and an almost significant decrease in free testosterone levels, suggesting that Arg148 alleles in the gp130 gene have a protective effect against androgen excess and adrenal hyperactivity. Discussion: Polymorphisms in the gp130 and IL6R‐α loci influence hyperandrogenism and obesity, respectively. Our present results further suggest that proinflammatory genotypes are involved in the pathogenesis of these common metabolic disorders.     

The combined effects of anti-TNFalpha antibody and IL-1 receptor antagonist in human rheumatoid arthritis synovial membrane

TNFalpha and IL-1 are the pivotal cytokines involved in rheumatoid arthritis (RA). More recently, the biological therapy targeting TNFalpha or IL-1 has been impressively effective for many RA patients, however, it remains insufficient in some patients. In the present study, we examined the combined effects of two agents against TNFalpha and IL-1 in human RA synovial membrane. Synovial explants (an ex vivo model) and synovial fibroblasts (an in vitro model) were prepared from 11 RA patients, and then anti-TNFalpha antibody (Anti-TNFalpha) and IL-1 receptor antagonist (IL-1Ra), either alone or in combination, were added to the synovial explants and fibroblasts. IL-6 and MMP-3 production were measured after incubation. As a result, their production significantly decreased by the combination of agents compared with the control group in both the synovial explants and fibroblasts. The efficacy of this combination was also observed for IL-6 production compared with each agent alone in the synovial explants, and for IL-6 and MMP-3 production compared with each agent alone in the synovial fibroblasts. Therefore, the combination of Anti-TNFalpha and IL-1Ra appears more beneficial in synovial membrane, particularly when compared with a single agent alone.     

Blockade of SDF-1/CXCR4 reduces adhesion-mediated chemoresistance of multiple myeloma cells via interacting with interleukin-6

Resistance to chemotherapy represents a major cause for treatment failure in multiple myeloma (MM). Herein, this study was conducted to explore the effect of SDF-1/CXCR4 and interleukin-6 (IL-6) in MM cell adhesion-mediated chemoresistance. Enzyme-linked immunosorbent assay was applied to detect expressions of SDF-1α and IL-6 in MM patients and healthy controls. RPMI-8226 cells and isolated bone marrow stromal cells (BMSCs) were stimulated using recombinant SDF-1α and IL-6. Effect of cocultured BMSCs and RPMI-8226 cells on chemosensitivity and apoptosis of RPMI-8226 cells was analyzed. Effect of doxorubicin on the adhesion rate of RPMl-8226 cells to BMSCs was analyzed by calcitonin test. Effect of SDF-1α-induced upregulation of IL-6 on chemotherapeutic resistance and apoptosis of RPMI-8226 cells in adhesion state was analyzed. Cell adhesion model was treated with recombinant protein SDF-1α and phosphoinositide 3-kinase (P13K) inhibitor Wortmarmin. The levels of P13K and protein kinase B (AKT) and its phosphorylation as well as the expression of IL-6 were analyzed. SDF-1α was positively correlated with IL-6. Recombinant human SDF-1α increased IL-6 expression and induced IL-6 secretion in a time- and dose-dependent manner in BMSCs, which was inhibited by IL-6 and SDF-1α neutralizing antibodies. Coculture of MM cells with BMSCs increased the drug resistance and inhibited the apoptosis on MM cells. SDF-1α-induced IL-6 upregulation mediates chemoresistance and apoptosis of RPMI-8226 cells in adhesion state. SDF-1α may up-regulate the expression of IL-6 by activating the P13K/AKT signaling pathway. SDF-1/CXCR4 may up-regulate the expression of IL-6 through the activation of the P13K/AKT signaling pathway, thereby affecting the chemoresistance mediated by adhesion in MM cells.     

Estrogen‐related receptor alpha triggers the proliferation and migration of human non‐small cell lung cancer via interleukin‐6

Human non‐small cell lung cancer (NSCLC) is one of the leading causes of cancer deaths worldwide. Estrogenic signals have been suggested to be important for the growth and metastasis of NSCLC cells. Our present data showed that estrogen‐related receptor alpha (ERRα), while not ERRβ or ERRγ, was significantly elevated in NSCLC cell lines as compared with that in normal bronchial epithelial cell line BEAS‐2B. The expression of ERRα in clinical NSCLC tissues was significantly greater than that in their matched normal adjacent tissues. Over expression of ERRα can trigger the proliferation, migration, and invasion of NSCLC cells, while si‐ERRα or ERRα inhibitor showed opposite effects. ERRα can increase the mRNA and protein expression of IL‐6, while not IL‐8, IL‐10, IL‐22, VEGF, TGF‐β, or TNF‐α, in NSCLC cells. Silence of IL‐6 attenuated ERRα induced proliferation and cell invasion. Furthermore, our data revealed the inhibition of NF‐κB, while not ERK1/2 or PI3K/Akt, abolished ERRα induced production of IL‐6. This might be due to that overexpression of ERRα can increase the expression and nuclear translocation of p65 in NSCLC cells. Collectively, our data showed that activation of NF‐κB/IL‐6 is involved in ERRα induced migration and invasion of NSCLC cells. It suggested that ERRα might be a potential target for NSCLC treatment.     

TL1A increased IL-6 production on fibroblast-like synoviocytes by preferentially activating TNF receptor 2 in rheumatoid arthritis

TNF-like protein 1A (TL1A), a member of tumor necrosis factor family, recognized as a ligand of death receptor 3 (DR3) and decoy receptor 3 (DcR3). The interaction of TL1A and DR3 may participate in the pathogenesis of some autoimmune diseases including rheumatoid arthritis (RA). Our previous results showed that high concentrations of TL1A could be found in synovial and serum in RA patients, and it was correlated with disease severity. In addition, TL1A could promote Th17 differentiation induced by TGF-β and IL-6 and increased the production of IL-17A. In the present study, we found that TL1A could promote the expression of IL-6 on fibroblast-like synoviocytes (FLS) of RA patients via NF-κB and JNK signaling pathway. TL1A-stimulated FLS increased the percentage of Th17 of peripheral blood mononuclear cells (PBMC) in RA via the production of IL-6, a critical cytokine involved in the differentiation of Th17. Moreover, the blocking of tumor necrosis factor receptor 2 (TNFR2) decreased TL1A-stimulated IL-6 production by RA FLS. Our results suggest that TL1A was capable of acting on RA FLS to elevate IL-6 expression, which promoted the production of Th17. More importantly, we showed that TL1A could influence RA FLS through binding to TNFR2 rather than DR3 on FLS, which indicated that the treatment of TNF inhibitors not only blocked the TNF but also suppressed the TL1A in RA patients.     

Production of TNFα and IL-6 by Activated Whole Blood from HIV-1 Infected Patients Detected by a One-Stage Procedure: Relationship with the Phenotype of HIV-1 Isolates

Diluted whole blood (WB) culturing may be the most appropriate milieu in which to study cytokine production in vitro. We tested TNFα and IL-6 production using small volumes of WB (25 μl) from HIV-1 positive patients with a one-step procedure that combines WB stimulation with LPS, PHA and cytokine measurement. We studied 49 patients without secondary infection or at distance of secondary infection staged according to the 1993 classification of the CDC and 12 healthy seronegative subjects. Heparinized blood from 5 control subjects had been collected sequentially during a period of 5 months. The individual variations of TNFα and IL-6 production were limited for all these individuals. In 1 out of 20 CDC group A patients, 6 out of 17 CDC group B patients and 3 out of 12 CDC group C patients, we obtained higher values of TNFα than the mean + 2 S.D. of the control group. In 3 out of 20 CDC group A patients, 1 out of 17 CDC group B patients without AIDS and 5 out of 12 CDC group C patients, the TNFα values were lower than the mean ?2 S.D. of the control group. Low IL-6 values were obtained in 1 out of 20 CDC group A patients and 1 out of 17 CDC group B patients and 3 out of 12 CDC group C patients. There was no correlation between TNFα production in vitro and plasma level of TNFα. We found no correlation between the levels of cytokines and monocyte count or between the levels of cytokines and CD4 T-cell count in peripheral blood. Our data point out a disarray in TNFα and IL-6 production by WB from HIV-1 infected patients. The relationship between the disarray of cytokine production and cytopathogenicity of HIV-1 isolates in the P4 cell line was investigated in this study. We found a correlation between the high level of TNFα produced by WB and the phenotype of HIV-1 isolates isolated from patients. The one-stage procedure used in this work is of potential value to investigate the activation status of cells for monitoring HIV-1 positive individuals and predicting HIV-1 phenotype.     

Production of IL-6, in contrast to other cytokines and chemokines, in macrophage innate immune responses: effect of serum and fungal (Blastomyces) challenge

Murine peritoneal macrophages, after adherence and establishment in culture in vitro in the presence of medium containing fetal bovine serum (FBS) for 20 h, then cultured for 20 h, produced several cytokines. If, in the second 20 h period, a fungus (heat-killed Blastomyces, HK-Bd) was introduced, a more complex pattern of cytokine (particularly TNF) and chemokine production ensued. The cytokine production, assayed by antibody array and also quantitation in supernatants, was depressed (particularly TNF) by the addition of mouse serum to these cultures, with the exception of IL-6. Macrophages could be cultured in the presence or absence of serum during the initial 20 h adherence and establishment period, enabling study of the effect of serum factors. In the absence of serum, with or without fungal stimulation, cytokine and chemokine production was more restricted, largely to TNF and IL-6. The addition of mouse serum [corrected] resulted in marked depression of TNF and enhancement of IL-6. The combination of HK-Bd and mouse serum resulted in more IL-6 production than either component alone. The enhancement of IL-6 by mouse serum was concentration-dependent and maximal at 8 h. The effects of fungus or serum on macrophage production of cytokines were similar in an outbred and an inbred mouse strain. The larger repertoire of cytokine production in the macrophages that had been cultured longer (20 h+20 h) in serum may be related to maturation of cell receptors. IL-6 production in vivo in response to fungal-serum complexes could affect pathogenesis by opposing the host defense modulation by proinflammatory cytokines or by modulating the destructive effects of inflammation on host tissues.     

Involvement of PKC-β in PTH, TNF-α, and IL-1β Effects on IL-6 Promoter in Osteoblastic Cells and on PTH-Stimulated Bone Resorption

Protein kinase C (PKC) has been shown to be activated by parathyroid hormone (PTH) in osteoblasts. Prior evidence suggests that this activation mediates responses leading to bone resorption, including production of the osteoclastogenic cytokine interleukin-6 (IL-6). However, the importance of specific PKC isozymes in this process has not been investigated. A selective antagonist of PKC-β, LY379196, was used to determine the role of the PKC-β isozyme in the expression of IL-6 in UMR-106 rat osteoblastic cells and in bone resorption in fetal rat limb bone organ cultures. PTH, tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) induced translocation of PKC-α and -β_I to the plasma membrane in UMR-106 cells within 5 min. The stimulation of PKC-β_I translocation by PTH, TNF-α or IL-1β was inhibited by LY379196. In contrast, LY379196 did not affect PTH, TNF-α-, or IL-1β-stimulated translocation of PKC-α. PTH, TNF-α, and IL-1β increased luciferase expression in UMR-106 cells transiently transfected with a −224/+11 bp IL-6 promoter-driven reporter construct. The IL-6 responses were also attenuated by treatment with LY379196. Furthermore, LY379196 inhibited bone resorption elicited by PTH in fetal rat bone organ cultures. These results indicate that PKC-β_I is a component of the signaling pathway that mediates PTH-, TNF-α-, and IL-1β-stimulated IL-6 expression and PTH-stimulated bone resorption.     

Prerequisites for Functional Interleukin 31 Signaling and Its Feedback Regulation by Suppressor of Cytokine Signaling 3 (SOCS3)

Interleukin-31 (IL-31) is a T helper type 2 cell-derived cytokine tightly associated with inflammatory skin disorders. IL-31-induced signaling is mediated by a receptor complex composed of oncostatin M receptor β and the cytokine-specific receptor subunit IL-31Rα, of which there are several isoforms. The latter can be classified as long or short isoforms with respect to their intracellular domain. At present, the signaling capabilities of the different isoforms remain inchoately understood, and potential mechanisms involved in negative regulation of IL-31Rα signaling have so far not been studied in detail. Here, we show that both the long and short isoforms of IL-31Rα are capable of inducing STAT signaling. However, the presence of a functional JAK-binding box within IL-31Rα is an essential prerequisite for functional IL-31-mediated STAT3 signaling. Moreover, both the long and short isoforms require oncostatin M receptor β for their activity. We also show that IL-31 induces expression of four suppressor of cytokine signaling family members and provide evidence that SOCS3 acts as a potent feedback inhibitor of IL-31-induced signaling. Taken together, this study identifies crucial requirements for IL-31 signaling and shows its counter-regulation by SOCS3.