Soluble cytokine receptors in biological therapy

Due to their fundamental involvement in the pathogenesis of many diseases, cytokines constitute key targets for biotherapeutic approaches. The discovery that soluble forms of cytokine receptors are involved in the endogenous regulation of cytokine activity has prompted substantial interest in their potential application as immunotherapeutic agents. As such, soluble cytokine receptors have many advantages, including specificity, low immunogenicity and high affinity. Potential disadvantages, such as low avidity and short in vivo half-lifes, have been addressed by the use of genetically-designed receptors, hybrid proteins or chemical modifications. The ability of many soluble cytokine receptors to inhibit the binding and biological activity of their ligands makes them very specific cytokine antagonists. Several pharmaceutical companies have generated a number of therapeutic agents based on soluble cytokine receptors and many of them are undergoing clinical trials. The most advanced in terms of clinical development is etanercept (Enbrel, Immunex), a fusion protein between soluble TNF receptor Type II and the Fc region of human IgG1. This TNF-alpha; antagonist was the first soluble cytokine receptor to receive approval for use in humans. In general, most agents based on soluble cytokine receptors have been safe, well-tolerated and have shown only minor side effects in the majority of patients. Soluble cytokine receptors constitute a new generation of therapeutic agents with tremendous potential for applications in a wide variety of human diseases. Two current areas of research are the identification of their most promising applications and characterisation of their long-term effects.     

首发精神分裂症患者细胞因子水平对照研究

目的 探讨首发精神分裂症患者的细胞因子水平,为揭示精神分裂症的病因、发病机制、临床诊断及治疗提供理论依据.方法 将78例首发精神分裂症患者设为研究组,35名正常健康体检者设为对照组,采用放射免疫分析法检测两组血浆白细胞介素-1β、白细胞介素-2、白细胞介素-6、白细胞介素-8、肿瘤坏死因子-α,研究组于治疗1周、8周末采用阳性与阴性症状量表评定精神症状.结果 研究组血浆白细胞介素-1β、白细胞介素-2、白细胞介素-6、白细胞介素-8、肿瘤坏死因子-α水平均显著高于对照组(P＜0.05或0.01).研究组血浆肿瘤坏死因子-α升高与白细胞介素-1β水平升高呈显著正相关,阳性与阴性症状量表评分与白细胞介素水平无显著相关性.Ⅰ型精神分裂症患者白细胞介素-2水平显著高于Ⅱ型患者(P＜0.01),白细胞介素-8水平显著低于Ⅱ型患者(P＜0.05).结论 精神分裂症患者的免疫功能处于亢进状态,细胞因子水平与精神病理存在一定相关性.     

Soluble leptin receptors and serum leptin in end-stage renal disease: relationship with inflammation and body composition

BACKGROUND: Elevated serum leptin (S-leptin) levels have been reported in patients with end-stage renal disease (ESRD). Apart from the decreased glomerular filtration rate (GFR), body composition and inflammation may affect leptin levels in ESRD. Leptin circulates both free of and bound to soluble leptin receptors (sOB-R), which are the main determinants of leptin activity and have not been described in ESRD until now. DESIGN: To analyze the association between S-leptin, sOB-R, and inflammation and body composition, we studied 149 (62% males) normal weight (BMI 24.7 +/- 0.4 kg m(-2)) ESRD patients (51 +/- 1 years old) shortly before the start of dialysis (GFR 7.0 +/- 0.2 mL min(-1)). sOB-R and plasma interleukin-6 (IL-6; n= 113) levels were evaluated using ELISA, S-leptin using RIA, and body composition was assessed by X-ray absorptiometry (n = 139). Forty-one healthy subjects age (51 +/- 1 years), BMI (23.6 +/- 0.5 kg m(-2)) and gender-matched (59% males) were used as controls. RESULTS: Median S-leptin was higher in the ESRD patients (10.0 ng mL(-1)) compared with the controls (3.9 ng mL(-1)) (P < 0.001). The median sOB-R did not differ significantly between the ESRD patients (44 U mL-1) and the controls (37 U mL-1). Thus, the sOB-R/S-leptin ratio was lower in the ESRD patients (9.5 +/- 1.2 vs. 12.3 +/- 1.8; P < 0.01) than the controls. A negative correlation was observed between S-leptin and sOB-R (Rho = -0.42; P < 0.0001) in the ESRD patients, a positive correlation was observed between lean body mass and the sOB-R/S-leptin ratio (Rho = 0.33, P = 0.0001) whereas fat mass was negatively correlated to both sOB-R (Rho = -0.26, P = 0.002), and the sOB-R/S-leptin ratio (Rho = -0.62, P < 0.0001). Positive correlations were observed between IL-6 and S-leptin (Rho = 0.19; P < 0.05) and weak but significant body fat mass (Rho = 0.20; P < 0.05), respectively. CONCLUSIONS: This study demonstrates that despite markedly elevated S-leptin levels in the ESRD patients, sOB-R did not differ from the controls. In view of the anorexigenic and pro-atherogenic effects of leptin, further elucidation of the consequences of free bioactive leptin in the development of complications such as malnutrition and cardiovascular disease in ESRD patients is required.     

Soluble interleukin-2 receptors increase during the active periods in cluster headache

OBJECTIVE: To investigate whether cytokines are altered during the active period of cluster headache. BACKGROUND: Patients with cluster headache show activation of the hypothalamus in PET studies and via endocrinologic parameters. Data also suggest an inflammatory process occurs in cluster headache. A connection between the presumed inflammatory cause, an immunological activation, and the hypothalamus could be generated by certain cytokines. DESIGN AND METHODS: ELISA was used to determine the serum levels of soluble interleukin-2 receptors, interleukin-1, interleukin-6, and 2 soluble interleukin-6 receptors (sIL-6R and soluble gp130) in 18 patients with cluster headache (6 women and 12 men) during the cluster period and in 17 healthy controls who were headache-free (3 women and 14 men). RESULTS: Patients with cluster headache had significantly increased soluble interleukin-2 receptors (413.6+/-223 U/mL vs. 290.0+/-112 U/mL; P <.05) compared with controls. Serum levels of interleukin-1 (0.29+/-0.30 pg/mL vs. 0.13+/-0.13 pg/mL, n.s.), interleukin-6 (0.87+/-0.6 pg/mL vs. 0.91+/-0.7 pg/ml; n.s.), soluble interleukin-6 receptors (33,131+/-8,349 pg/mL vs. 35,063+/-7,606 pg/mL; n.s.), or soluble gp130 (289+/-59 pg/mL vs. 283+/-20 pg/mL; n.s.) did not differ between the 2 groups, although patients with cluster tended to have higher interleukin-1 values. CONCLUSIONS: Because elevated soluble interleukin-2 receptors indicate T cell activation, our findings suggest immune activation during cluster headache. Because interleukin-2 can activate the hypothalamus and stimulate the release of Corticotropin-releasing Factor (CRF), interleukin-2 could link a putative immunological cause of cluster headache with the observed hypothalamic activation. Systemic changes of interleukin-1 or the interleukin-6 system do not seem to play a role in cluster headache, as no alterations of serum levels were observed. Even so, unchanged serum levels do not exclude limited local production.     

Inflammatory cytokines and their receptors in arterial and mixed venous blood before, during and after infusion of drained untreated blood

Wound blood for postoperative autologous transfusion is drained through an area of damaged tissue, the surgical wound, and contains inflammatory mediators. The inflammatory cytokines interleukin-1-beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) and their modulators interleukin-1-receptor antagonist (IL-1Ra), interleukin 6 soluble receptor (IL-6sR), soluble tumour necrosis factor receptor 1 (sTNF-R1) and interleukin 10 (IL-10), together with white cell count (WCC) and white cell differential count were measured in arterial and mixed venous blood before, during and after infusion of postoperatively drained untreated blood in nine patients operated for thoracic scoliosis. We found a transient increase in IL-6, an increase in TNF-RI, an increase in IL-8 with granulocytosis and a decrease in IL-10 in the systemic circulation. The increase in IL-6 was higher in mixed venous than in arterial blood.     

Plasma cytokine levels in migraineurs and controls

BACKGROUND: The vasoactive peptide, calcitonin gene-related peptide (CGRP), is released from primary afferent neurons in the trigemino-vascular circulation during migraine headache. CGRP at physiological concentrations and possibly via stimulation of its selective receptors on T-cells, triggers the secretion of cytokines. Cytokines play an important role in several physiological and pathological settings such as immunology, inflammation, and pain. OBJECTIVE: To investigate plasma levels of pro- and anti-inflammatory cytokines in migraineurs and healthy controls. METHODS: We studied 25 migraine patients, during and outside attacks, and 18 healthy control subjects measuring plasma levels of IL-6, IL-10, tumor necrosis factor alpha (TNFalpha), IL-4, IL-1 beta, and IL-2 using ELISA. RESULTS: Circulating levels of IL-10, TNFalpha, and IL-1 beta during attacks were significantly higher in comparison to their levels outside attacks (P=.0003, P=.03, and P=.05, respectively). IL-10 and TNF serum levels were higher in patients studied soon after headache onset and lower over time (P=.004 and P=.05). CONCLUSION: Our results suggest that TNFalpha, IL-1 beta, and IL-10 may be involved in the pathogenesis of migraine attacks.     

Expert opinion on the use of biological therapy in non-infectious uveitis

Introduction: Conventional immunosuppressive drugs, anti-TNF alpha treatments and biotherapies are increasingly being used in non-infectious uveitis.

Areas covered: The present work was led by a multidisciplinary panel of experts, including internal medicine specialists, rheumatologists and ophthalmologists, and proposes an extensive review on the use of biological agents in non-infectious uveitis.

Expert opinion: In case of dependency to steroids or sight-threatening disease, conventional immunosuppressive drugs (methotrexate, azathioprine and mycophenolate mofetil) and/or biological therapies such as anti-TNF alpha treatments (adalimumab, infliximab) can be used to achieve and maintain disease quiescence. Interferon is an efficient immunomodulatory drug that can be proposed as second-line therapy in specific indications (eg. refractory macular edema, sight-threatening Behçet’s uveitis). Other biologics, especially tocilizumab, are showing promising results.

Local treatments (steroids, sirolimus etc.) can be used as adjuvant therapies in case of unilateral relapse. Therapeutic response must always be evaluated by clinical examination and appropriate ancillary investigations.     

Anti-cytokines: promising tools for diagnosis and immunotherapy

Anti-Cytokines belong to a new family of biological response modifiers which interfere with the biological functions of Cytokines. An imbalance between Cytokines and natural anti-Cytokines may represent an important factor to explain the pathogenesis of some human diseases. Indeed, dysregulation of anti-cytokine serum levels was observed in cancers and auto-immune and infectious diseases. It was sometimes associated with disease activity and in some circumstances they may help to predict clinical response to treatment. Control of disease activity in septic shock and auto-immune diseases was demonstrated after administration of anti-Cytokines such as soluble TNF receptors and ILlra inhibitors. Therefore these agents are promising tools for diagnosis and immunotherapy.     

Soluble cytokine receptors are present in normal human urine

Affinity chromatography of crude human urinary proteins on either human rIL-6, human rIFN-gamma, or anti-IFN-gamma-R mAb yielded the two respective soluble receptors in significant quantities. A single sequence of 30 amino acid residues was obtained by NH2-terminal microsequencing of the protein peak purified in tandem by affinity chromatography on an IL-6 column and reversed-phase HPLC. This sequence was identical to the predicted NH2-terminal sequence of IL-6-R as previously reported. Analysis of the eluted proteins from both IFN-gamma and anti-IFN-gamma-R columns by inhibition of solid phase RIA, ELISA, SDS-PAGE, and Western blotting proved the existence of soluble IFN-gamma-R in normal urine. Our finding, together with the already known presence of urinary TNF binding proteins and a soluble IL-2-R both in plasma and in urine, indicates that release of soluble cytokine receptors into body fluids is a general phenomenon that occurs under normal physiological conditions.     

血清炎性细胞因子与孤独症谱系障碍相关性的探讨

目的研究炎性细胞因子与孤独症谱系障碍(ASD)的相关性,寻找诊治该病的新的血清标志物。方法采用蛋白质芯片技术对20例ASD病例及20例健康对照儿童血清标本的干扰素γ、白细胞介素、巨噬细胞炎性蛋白等40种炎性细胞因子进行测定分析。结果 ASD病例组的粒细胞-巨噬细胞集落刺激因子,多种白细胞介素如IL-4、IL-5、IL-10、IL-11、IL-13、IL-17A,以及CXC类趋化因子9等细胞因子表达水平高于健康对照组(P0.05);而巨噬细胞炎性蛋白1α、巨噬细胞炎性蛋白1β、血小板源生长因子B亚基、CC类趋化因子5、金属蛋白酶组织抑制剂1、金属蛋白酶组织抑制剂2、肿瘤坏死因子受体Ⅱ等细胞因子表达水平低于健康对照组(P0.05)。结论 ASD儿童血清中巨噬细胞炎性蛋白等多种炎性细胞因子呈显著性升高或降低,提示ASD的发病机制与免疫系统受炎性刺激有关。     

Leukotriene receptors in atherosclerosis

Leukotriene‐forming enzymes are expressed within atherosclerotic lesions and locally produced leukotrienes exert pro‐inflammatory actions within the vascular wall by means of cell surface receptors of the BLT and CysLT receptor subtypes. The migration and accumulation of inflammatory cells that follow leukotriene receptor activation have been implicated in atherosclerosis initiation and progression. Leukotriene receptors are in addition expressed on endothelial and vascular smooth muscle cells, associated with intimal hyperplasia in early atherosclerosis and restenotic lesions after angioplasty. Taken together, recent evidence suggests that leukotriene receptors may be a potential target in the treatment of atherosclerosis and in the prevention of restenosis after coronary interventions.     

Streptococcus sanguinis‐induced cytokine release from platelets

Summary. Background: There is increasing evidence that both chronic and acute infections play a role in the development and progression of atherothrombotic disorders. One potential mechanism is the direct activation of platelets by bacteria. A wide range of bacterial species activate platelets through heterogeneous mechanisms. The oral micro‐organism S. sanguinis stimulates platelet aggregation in vitro in a strain‐dependent manner, although there are no reports of associated cytokine production. Objective: The aim of the present study was to determine whether platelet activation by S. sanguinis involved the release of pro‐inflammatory and immune modulating factors, and whether activation was enhanced by epinephrine. Methods and results: Four strains of S. sanguinis and one of S. gordonii stimulated the release of RANTES, PF4, sCD40L and PDGF‐AB, whereas only one S. sanguinis strain caused the release of sCD62p. Epinephrine enhanced S. sanguinis‐induced platelet aggregation and phosphorylation of phospholipase Cγ2 and Erk, but inhibited RANTES, PF4, sCD40L and PDGF‐AB release. Wortmannin inhibited S. sanguinis‐induced aggregation and release; however, only aggregation was partially reversed by epinephrine. Conclusions: The present study demonstrates that platelets respond to S. sanguinis with both prothrombotic and pro‐inflammatory/immune‐modulating responses. Epinephrine, potentially released in response to infection and/or stress, can significantly enhance the prothrombotic response, thereby providing a putative link between bacteraemia and acute coronary events during stress. In contrast, epinephrine inhibited the pro‐inflammatory/immune‐modulating response by an undetermined mechanism.     

Crucial role of the interleukin 1 receptor family member T1/ST2 in T helper cell type 2-mediated lung mucosal immune responses.

T1/ST2 is an orphan receptor of unknown function that is expressed on the surface of murine T helper cell type 2 (Th2), but not Th1 effector cells. In vitro blockade of T1/ST2 signaling with an immunoglobulin (Ig) fusion protein suppresses both differentiation to and activation of Th2, but not Th1 effector populations. In a nascent Th2-dominated response, anti-T1/ST2 monoclonal antibody (mAb) inhibited eosinophil infiltration, interleukin 5 secretion, and IgE production. To determine if these effects were mediated by a direct effect on Th2 cells, we next used a murine adoptive transfer model of Th1- and Th2-mediated lung mucosal immune responses. Administration of either T1/ST2 mAb or T1/ST2-Ig abrogated Th2 cytokine production in vivo and the induction of an eosinophilic inflammatory response, but failed to modify Th1-mediated inflammation. Taken together, our data demonstrate an important role of T1/ST2 in Th2-mediated inflammatory responses and suggest that T1/ST2 may prove to be a novel target for the selective suppression of Th2 immune responses.     

Th2 cytokine inhibition and cough in asthmatic and bronchitic patients

BACKGROUND: Activated T helper lymphocytes are present in the airway and their production of cytokines is important in the pathogenesis of asthma, however, the relationship between T helper lymphocyte‐derived cytokines and airway cough reflex sensitivity remains unknown. METHODS: The effect of the orally active Th2 cytokine inhibitor suplatast tosilate on cough response to inhaled capsaicin was examined in eleven patients with stable atopic asthma and compared with patients having non‐atopic asthma and chronic bronchitis (the latter of which is not related to Th2 cytokines). Capsaicin cough threshold, defined as the lowest concentration of capsaicin eliciting five or more coughs, was measured as an index of airway cough reflex sensitivity. Concentration of serum total IgE level was also measured after treatment with suplatast tosilate. RESULTS: The cough threshold after two weeks treatment with suplatast tosilate was significantly greater than the value with placebo accompanied by decrease of serum IgE level in atopic asthmatics. This significance was not observed in patients with non‐atopic asthma or chronic bronchitis. CONCLUSIONS: Th2 cytokines may be possible modulators augmenting airway cough reflex sensitivity in atopic asthmatic airways but not in non‐atopic asthmatic or bronchitic airways.     

Human cancer gene therapy with cytokine gene-modified cells

Cytokines can impede tumour growth and activate innate and adaptive immune responses, leading to elimination of cancer cells. For many years, it was believed that systemic administration of recombinant cytokines might become a standard treatment of different cancer types. However, due to a high toxicity of therapeutic doses and a low efficacy, even in combination with chemotherapy, this strategy is generally not accepted. On the other hand, cancer gene therapy approaches utilising cells modified with cytokine genes seem to represent a novel promising approach. For the last decade, numerous Phase I and II clinical trials evaluating different therapies based on cytokine gene-modified cells have been carried out. In the early studies, several strategies have been shown to improve clinical outcomes and induce strong antitumour immune responses. Recently, a few prospective, randomised, Phase III clinical trials have been initiated in order to finally determine the efficacy of particular cancer immunogene therapy strategies. This article reviews the present status and perspectives of clinical trials of cancer immunotherapies utilising cytokine gene-modified cells.     

雷公藤甲素治疗糖皮质激素抵抗型支气管哮喘

目的　观察雷公藤甲素对糖皮质激素抵抗型 (SR)支气管哮喘 (哮喘 )患者血清细胞因子水平、哮喘症状和肺功能的影响 ,探讨雷公藤甲素对SR哮喘有无治疗作用。方法　SR哮喘患者 16例 ,随机分组为A、B 2组 ,每组各8例。 2组患者均予口服丙卡特罗 5 0～ 10 0 μg/d和茶碱 4 0 0mg/d ,并急性发作时吸入沙丁胺醇 2 0 0～ 80 0 μg/d。A组患者同时联合应用雷公藤甲素 33μg/次 ,口服 ,每日 3次。疗程 4周。疗程开始及结束时分别行血清干扰素 (IFN) γ、白细胞介素 (IL) 4、IL 5水平测定 ,哮喘临床积分和肺功能检查。结果　治疗后 ,A组患者血清IFN γ和肺功能指标用力肺活量 (FVC % )、第 1秒钟用力呼气容积 (FEV1% )、最大呼气流量 (PEF % )、5 0 %肺活量时最大呼气流量( V50 % )、2 5 %肺活量时最大呼气流量 ( V2 5% )均显著增高 ,哮喘临床积分和血清IL 4、IL 5显著降低 (与A组治疗前比较P <0 .0 1;与B组治疗后比较P <0 .0 5 )。B组治疗后与治疗前比较 ,上述各项指标均无显著改变 (P >0 .0 5 )。结论　雷公藤甲素是治疗SR哮喘的有效选择。