Interleukin-1 receptor antagonist as a treatment of HIV infection

The human immunodeficiency virus (HIV) apparently utilizes human chromosome 2, interleukin-1 (IL-1), glucocorticoid hormones, and viral Tat protein to accelerate its replication and the synthesis of all HIV proteins. HIV Tat protein binds to the long terminal repeat (LTR) ribonucleic acid, including the trans-acting responsive (TAR) sequence and the promoter region to increase HIV replication. Tat-TAR transactivation requires a factor encoded on the long arm of chromosome 2. The interaction of HIV with chromosome 2 may also cause the observed inhibition of interleukin-1 receptor antagonist (IL-1RA), thus increasing the production of IL-1. IL-1, in turn, stimulates the HIV-1 enhancer region of the LTR, thus increasing HIV gene expression and replication. IL-1 also induces glucocorticoid hormone synthesis which stimulates HIV in the virion infectivity factor (Vif) region, thus increasing HIV infectivity. It is, thus, proposed that IL-1RA not only may serve to inhibit HIV-induced IL-1, but may be the unidentified human chorionic gonadotropin-associated factor recently found to have anti-HIV and anti-Kaposi's sarcoma activity.     

Interleukin-1 as a possible agent for treatment of infection

Treatment of experimental animals with bacterial products, such as cell wall components of gram-negative bacteria, leads to enhanced resistance to a variety of microorganisms. Since interleukin-1 and other pro-inflammatory cytokines are induced by such bacterial products, it has been investigated whether these cytokines are induced by such bacterial products, it has been investigated whether these cytokines are also capable of enforcing host resistance. It has been possible to demonstrate that a low dose of interleukin-1 protects mice against death from either gram-negative or gram-positive bacteria,Candida albicans andPlasmodium berghei. The protection against lethal bacterial and fungal infection can be produced in both normal and neutropenic animals. Despite extensive investigations, the mechanism of protection is not understood. A possible mechanism, which is currently being investigated, is that interleukin-1 interferes with the deleterious action of the pro-inflammatory cytokines during the lethal phase of the infection.     

Interleukin-1 receptor antagonist (IL-1ra) as a probe and as a treatment for IL-1 mediated disease.

The natural human IL-1 receptor antagonist (IL-1ra) has been produced in a recombinant organism and has been used to study IL-1 action in vivo. The receptor antagonist mitigates the pathophysiology associated with animal models of ulcerative colitis through reducing IL-1 mediated neutrophil recruitment into the affected tissue. It also reduces joint swelling and damage in an animal model of rheumatoid arthritis, possibly by reducing IL-1 mediated synthesis of proteases by the synovial fibroblasts and chondrocytes of the joint. The receptor antagonist is not immunosuppressive in rodents, indicating that it is working by blocking the inflammatory reaction rather than any underlying defect in specific immunity.     

Interleukin-1 receptor antagonist gene polymorphism,vaginal interleukin-1 receptor antagonist concentrations,and vaginal ureaplasma urealyticum colonization in pregnant women

Ureaplasma urealyticum is the microorganism most frequently isolated from amniotic fluids of women in preterm labor. The relationship between vaginal colonization with U. urealyticum, vaginal interleukin-1 receptor antagonist (IL-1ra) levels, and the IL-1ra genotype in pregnant women was examined. Vaginal specimens, obtained with a cotton swab from 207 women in their first trimester of pregnancy, were tested for IL-1ra concentrations by enzyme-linked immunosorbent assay and for U. urealyticum and IL-1ra genotypes by PCR. U. urealyticum was detected in 85 (41.1%) women. The median IL-1ra level was 450 ng/ml in women positive for U. urealyticum, as opposed to 225 ng/ml in women negative for this microorganism (P < 0.0001). Sixty-two percent of the 16 women who were homozygous for allele 2 of the IL-1ra gene (IL-1RN*2) were colonized with U. urealyticum, as opposed to 47% of the 49 women who were IL-1RN*1/IL-1RN*2 heterozygotes and 34% of the 133 women who were IL-1RN*1 homozygotes (P < 0.05). Median IL-1ra levels were 750 ng/ml in IL-1RN*2 homozygotes, 300 ng/ml in IL-1RN*1/IL-1RN*2 heterozygotes, and 250 ng/ml in IL-1RN*1 homozygotes (P = 0.02). The vast majority of subjects had an uneventful pregnancy and delivered a healthy infant at term. The IL-1ra genotype or U. urealyticum colonization was unrelated to birth weight. Pregnant women who are colonized with U. urealyticum during the first trimester have elevated vaginal IL-1ra concentrations and a higher prevalence of the IL-1RN*2 homozygote genotype than do noncolonized women.     

IL-1β血清水平及IL-1B和IL-1受体拮抗剂基因多态性与胃癌关系探讨

目的 探讨白细胞介素(IL)-1β血清水平及IL-1B和IL-1RN基因多态性与胃癌及幽门螺杆菌(Hp)感染胃癌发生发展的相关性.方法 以酶联免疫吸附试验(ELISA)测定IL-1β血清水平及抗Hp抗体IgG、IgM和IgA浓度;采用基因芯片技术检测260例胃癌患者和284例不相关联的健康对照人群中IL-1B-31C/T、-511C/T位点单核苷酸多态性(SNP);以琼脂糖凝胶电泳检测IL-1RN基因多态性(VNTR).结果 胃癌组IL-1β血清水平[(802±148) ng/L]显著高于对照组[(501±125) ng/L],P<0.01;胃癌组Hp感染率明显高于对照组[P<0.001, 相对危险度(OR)=2.59].胃癌组IL-1B-31TT基因型频率明显高于对照组(P<0.01,OR=1.95);胃癌组IL-1B-511TT基因型频率明显高于对照组(P<0.05,OR=1.62);Hp阳性(Hp+)胃癌组-511TT基因型频率明显高于Hp阴性(Hp-)胃癌(P<0.05,OR= 2.00);胃癌组T-T单体型频率显著高于对照组(χ2=4.45,P<0.05).不论在胃癌组还是在Hp+胃癌组,携带IL-1B-31T或-511T等位基因者血清IL-1β水平均高于其相应CC基因型携带者,且IL-1B-31T、-511T携带者在Hp+胃癌组较Hp-胃癌组的IL-1β水平显著增高(P<0.001).未见IL-1RN基因型及其他IL-1B基因型与胃癌或Hp+胃癌有显著相关性.结论 IL-1B-31TT基因型与胃癌易感性相关;IL-1B-511TT基因型与胃癌特别是Hp+胃癌易感性相关.IL-1B-31T/-511T等位基因均与IL-1β血清水平显著相关(P<0.001).T-T单体型可能是胃癌的遗传易感因素.     

Interleukin-1 receptor antagonist protein inhibits interleukin-8 expression in lipopolysaccharide-stimulated human whole blood.

Interleukin-8 (IL-8) is a neutrophil and lymphocyte chemoattractant and activator that may play an important role in mediating events at sites of inflammation. IL-8 is produced by many cell types in response to a variety of inducers, including interleukin-1 (IL-1). Studies were conducted to address the question of whether an inhibitor of IL-1 action, IL-1 receptor antagonist protein (IRAP), would suppress IL-8 production. Lipopolysaccharide (LPS)-stimulated human whole blood was used as an ex vivo model of local cytokine production. Preliminary time course studies showed that plasma IL-1 beta levels were fully induced by 6 hours (approximately 15 ng/ml) and persisted at this level over 24 hours. IL-8 production, in contrast, reached a plateau between 6 to 12 hours (5 ng/ml) and then increased rapidly to 17 ng/ml at 24 hours. Addition of IRAP was found to dose-dependently inhibit IL-8 expression at the levels of both protein and mRNA. A 50% reduction in IL-8 protein release occurred at an IRAP dose of 8 micrograms/ml (5 x 10(-7) mol/l) at 24 hours. A 2 hour delay in the addition of IRAP relative to LPS still permitted optimal reduction in IL-8 release, whereas delays of 4-8 hours reduced or eliminated the inhibitory effect. IRAP was found to have no effect on the LPS-stimulated production of IL-1 alpha or IL-1 beta. In addition, experiments performed with isolated peripheral blood cells demonstrated that, whereas monocytes were the major producers of IL-8, IRAP was equally effective in reducing IL-8 production in neutrophil and mononuclear cell suspensions. These studies further document the role of IL-1 in inducing the production of IL-8 and indicate that the ability of IRAP to suppress IL-8 expression may be an important mechanism of the anti-inflammatory properties of this molecule.     

A novel mutation in the interleukin-1 receptor antagonist associated with intrauterine disease onset

Deficiency of the IL-1 receptor antagonist (DIRA) is a recently described rare autoinflammatory disease, caused by loss of function mutations in IL1RN leading to the unopposed activation of the IL-1 pathway. We describe a novel nonsense mutation in the IL1RN gene, associated with early intrauterine onset, death and multiorgan involvement in a prematurely born baby. The protein prediction model indicated that the novel Q119X mutation would result in a nonfunctional protein by impairing the ability of the IL-1Ra to bind and antagonize signaling through the IL-1R. Since the disorder may mimic severe bacterial infections and the treatment with anakinra is life saving, we intend to raise awareness of the syndrome and the possibility of a founder mutation that may lead to the diagnosis of additional cases in Turkey. The clinical suspicion of DIRA is critical to avoid improper management of the patients with antibiotics alone and death from multiorgan failure.     

Interleukin-1 receptor antagonist in newborn babies and pregnant women

We have used patch-clamp techniques to study the effect of the sulfhydryl group oxidizing agents mercury and thimerosal on calcium-activated nonselective cation channels from brown adipose tissue. 100 nmol/l mercury and 50 mol/l thimerosal induced a complete block. Blockade could be reversed by reduction of the mercaptide by dithiotreitol (DTT). Mercury was found to be the most potent blocker (IC₅₀-value 21×10^–9 mol/l), whereas thimerosal (IC₅₀-value 1.5×10^–6 mol/l) was as effective as 3,5-dichlorodiphenylamine-2-carboxylic acid (DCDPC). The DCDPC effect, however, could not be reversed by DTT, indicating different blocking mechanisms. It is concluded that SH-groups are involved in gating of the calcium-activated nonselective channel.     

In vivo transfer of interleukin-1 receptor antagonist gene in osteoarthritic rabbit knee joints: prevention of osteoarthritis progression

The goal of this study was to determine the efficacy of local IL-1Ra gene therapy by intra-articular plasmid injections on structural changes in the meniscectomy rabbit model of osteoarthritis. A partial meniscectomy of the right knee was performed on the rabbits through a medial parapatellar incision. The rabbits were then divided into four experimental groups. Group 1 received no treatment. Group 2 received three consecutive intra-articular injections at 24-hour intervals of 0.9% saline containing a lipid, gammaAP-DLRIE/DOPE, and a DNA plasmid, VR1012. Group 3 received three consecutive injections of saline containing 1000 microg of canine IL-1Ra plasmid and lipid. The injections were given starting 4 weeks post-surgery. Rabbits from Group 1 were killed 4 weeks post-surgery, and all other rabbits 8 weeks post-surgery. The severity of macroscopic and microscopic changes on cartilage on the medial and femoral condyles and tibial plateaus and synovium were graded separately. Specimens were also processed for immunohistochemical staining using a rabbit polyclonal antibody against canine IL-1Ra. The level of canine IL-1Ra in synovial fluid was determined using enzyme-linked immunosorbent assay. The presence of the DNA plasmid in the synovium was tested by polymerase chain reaction. A significant reduction in the width of osteophytes and size of macroscopic lesions (P < 0.04) was observed, and was dependent on the amount of IL-1Ra plasmid injected. A significant reduction was also noted in the severity of histologic cartilage lesions (P < 0.01) in the group that received the highest dosage (1000 microg) of IL-1Ra plasmid. IL-1Ra was detected in synovial fluid by enzyme-linked immunosorbent assay and by immunohistochemical staining in the synovium and cartilage of rabbits that received injections containing the IL-1Ra plasmid. Polymerase chain reaction analysis of synovial DNA revealed the presence of the cloned cDNA dog IL-1Ra up to 4 weeks after the first intra-articular injection. This study demonstrates that direct in vivo transfer of the IL-1Ra gene into osteoarthritis knee cells using intra-articular injections of a plasmid vector and lipids can significantly reduce the progression of experimental osteoarthritis. This avenue may therefore represent a promising future treatment for osteoarthritis.     

Comparative responses of human and rabbit interleukin-1 in vivo: effect of a recombinant interleukin-1 receptor antagonist.

The ability of recombinant human and rabbit interleukin-1 alpha (IL-1 alpha) in inducing inflammatory responses in rabbit skin were compared. Intradermal (i.d.) injections of recombinant human IL-1 alpha and recombinant rabbit IL-1 alpha induced intense accumulation of 111In-labelled neutrophils which was dependent on the dose of the cytokines administered. Both forms of IL-1 alpha induced very small levels of plasma protein leakage. Co-injection of the cytokines with the mRNA synthesis inhibitor actinomycin D (Act D) attenuated the number of neutrophils accumulating in response to both human and rabbit forms of IL-1 alpha. Local injection of a recombinant human IL-1 receptor antagonist (IL-1Ra) caused a dose-dependent inhibition of local inflammatory responses initiated by human and rabbit IL-1 alpha s well as rabbit IL-1 beta indicating the species cross-reactivity of the antagonist. IL-1Ra was selective for IL-1 in rabbit skin, as responses induced by C5ades Arg and formyl-methionyl-leucyl-phenylalanine (FMLP) were not inhibited. IL-1Ra significantly inhibited the IL-1-induced neutrophil accumulation only when co-injected with the cytokine. The local administration of the antagonist 30 min after rabbit IL-1 alpha failed to inhibit the inflammatory response. These results suggest that the in vivo events leading to the accumulation of neutrophils in response to IL-1 alpha are rapidly initiated.     

Interleukin-1 receptor antagonist inhibits arthrofibrosis in a post-traumatic knee immobilization model

BackgroundTherapies for arthrofibrosis after knee surgery are needed to prevent loss of joint function. Interleukin-1 receptor antagonists (IL-1RA) have shown promise in treating established arthrofibrosis in pilot clinical studies. The objective of this study was to evaluate the ability of intra-articular injection of IL-1RA to prevent knee joint contracture in a post-traumatic knee immobilization model.Methods20 male Sprague Dawley rats were block randomized into two groups: control and IL-1RA. Rats underwent intra-articular surgical trauma of the right knee with placement of an immobilization suture, securing the knees in 150° flexion. On post-operative days 1 and 8, each group received a 0.1 ml intra-articular injection of either saline (control) or anakinra (IL-1RA:single dosage; 2.63 mg/kg). Rats were euthanized fourteen days after surgery and the immobilization femorotibial angles were measured on the operative limbs with the suture and musculature intact. Subsequently, musculature was removed and femorotibial angles were measured in the operative and non-operative limbs with a defined extension moment applied with the posterior capsule intact or cut. A contracture angle was calculated as the angular difference between the operative and non-operative limb.ResultsThe immobilization knee flexion angle did not differ (P = 0.761) between groups (control: 152 ± 9; IL-1RA: 150 ± 11). The joint contracture angles (smaller angle = improved outcome) were reduced by 12 degrees on average in the IL-1RA group compared to the control for both the capsule intact (P = 0.024) and cut (P = 0.019) states.ConclusionsIntra-articular IL-1RA injection was found to diminish knee extension deficits associated with arthrofibrosis in a post-traumatic joint immobilization model.     

Lipopolysaccharide induces human interleukin-1 receptor antagonist and interleukin-1 production in the same cell.

A new member of the interleukin-1 (IL-1) family has recently been described. Human IL-1 receptor antagonist (IL-1ra) is structurally related to IL-1 alpha and IL-1 beta but binds to IL-1 receptors on various target cells without demonstrable agonist activity. Understanding the mechanisms of regulation of IL-1ra production may clarify the biology of this unique cytokine as well as elucidate its possible role as a natural anti-inflammatory protein. The effects of lipopolysaccharide (LPS) on IL-1 alpha, IL-1 beta and IL-1ra production was studied at a single-cell level by use of cytokine-specific antibodies and indirect immunofluorescence technique. The peak synthesis of IL-1ra and IL-1 alpha/beta occurred in peripheral blood monocytes obtained from healthy blood donors within 4 and 6 h of cell stimulation, respectively. By double-staining procedure all IL-1ra-positive cells were also IL-1 alpha and/or beta positive. Thus, endotoxin induced simultaneous synthesis of the IL-1 gene family in the same cells. Only monocytes contributed to the production of IL-1 alpha, beta and IL-1ra during the 96 h of cell culture. The maximum number of IL-1ra-producing monocytes was 48 +/- 16% as compared to peak production of IL-1 alpha and beta which occurred in 75 +/- 9% and 80 +/- 12% (p < 0.001), respectively, of all peripheral blood monocytes. The incidence of IL-1 alpha- and beta-containing cells was not only significantly higher but also occurred for a longer time period, 72 h as compared to 24 h for IL-1ra localized in the Golgi organelle. However, IL-1ra-containing cells with a diffuse cytoplasmic appearance were also evident (20%-30%) at a later stage, 12 to 72 h after stimulation. Blocking IL-1 surface receptors by addition of exogenous recombinant IL-1 beta before stimulation could not inhibit the diffuse cytosolic localization. This indicates that the "late" staining pattern did not reflect IL-1ra being secreted and internalized after binding to extracellular receptors. Thus, perhaps IL-1ra modulates IL-1 effector mechanisms by receptor interactions both inside and outside the cell.     

Interleukin-1beta and interleukin-1 receptor antagonist gene polymorphism in postmenopausal women: correlation to bone mineral density and susceptibility to osteoporosis

OBJECTIVE: Osteoporosis is a common disorder with a strong genetic component. Our aim was to investigate the correlations of the interleukin-1beta (IL-1beta) and interleukin-1 receptor antagonist (IL-1Ra) gene polymorphisms with bone mineral density (BMD) and their relationship to osteoporosis. METHODS: The IL-1beta (promoter and exon 5) and IL-1Ra (intron 2) gene polymorphisms were determined using polymerase chain reaction. BMD of the lumbar spine and proximal femur were measured using dual-energy X-ray absorptiometry. RESULTS: The prevalence of each genotype of the interleukin-1 related genes in the study population was: (1) 14% C/C, 71.5% C/T, and 14.5% T/T in IL-1beta promoter; (2) 95.3% E1/E1 and 4.7% E1/E2 in IL-1beta exon 5; (3) 92.4% I/I, 6.4% I/II, and 1.2% II/II in IL-1Ra intron 2. After adjustment for potential confounding factors such as age, height, weight, years since menopause, and daily calcium intake, subjects with genotype E1/E2 (n=8) in IL-1beta exon 5 had lower BMD values and a significantly greater risk for osteoporosis (OR 10.6, 95% CI 1.3-83.8) at the lumbar spine when compared with subjects with genotype E1/E1 (n=164) in IL-1beta exon 5. CONCLUSION: The Taq I IL-1beta exon 5 gene polymorphism is associated with reduced BMD and predisposes women to osteoporosis at the lumbar spine, but our results should be interpreted with caution because of the small number of subjects with the unfavorable E1/E2 genotype.     

白介素1β及白介素1受体拮抗剂基因多态性与哮喘的相关性研究

哮喘是一种多基因遗传病,是由多种基因和环境因子相互作用引起.目前认为IL-1基因多态性与多种慢性炎症性疾病有关[1].本文应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)技术和PCR技术初步探讨IL-1β基因启动子区域(-511C/T)和IL-1RN基因第2内含子可变数目串联重复序列(VNTR)多态性与人群哮喘的关系.     

Polymorphisms in interleukin-1beta and interleukin-1 receptor antagonist genes and malaria in Ghanaian children

We have investigated the possible associations between polymorphisms in two interleukin-1 (IL-1) genes and severity of Plasmodium falciparum malaria in Ghanaian children with cerebral malaria, severe anaemia or uncomplicated malaria and controls. There was no significant difference in genotype and allele frequencies in IL-1beta exon 5 or interleukin-1 receptor antagonist (IL-1ra) polymorphisms between the studied groups, suggesting that the two polymorphisms may not be involved in the pathogenesis of severe malaria. When parasitaemias in uncomplicated malaria patients were evaluated, a significantly higher level of parasitaemia was observed among carriers of IL-1beta A2 allele as compared with noncarriers of this allele (P = 0.01). The mean parasitaemia in an age-matched asymptomatic group did not reveal such associations. These data suggest that IL-1beta exon 5 allele 2 may play a possible role in the clinical outcome of uncomplicated malaria.     

Glomerular expression of interleukin-1 receptor antagonist and interleukin-1 beta genes in antibody-mediated glomerulonephritis.

Interleukin-1 (IL-1) is a powerful proinflammatory cytokine whose function is modulated by a natural IL-1 receptor antagonist (IL-1ra). There are few data about kinetics of in vivo synthesis of IL-1ra at tissue level, except in response to bacterial endotoxin. The purpose of this study was to examine the kinetics of local expression of IL-1ra gene in relation to IL-1 beta gene in a model of anti-glomerular basement membrane antibody-mediated glomerulonephritis. Rats were killed in groups of 5 or 6 at 0, 4, 6, 24, 48, and 96 hours after induction of glomerulonephritis. Messenger RNA for IL-1ra and IL-1 beta was undetectable by Northern blot in normal glomeruli but increased markedly 4 to 6 hours after induction of nephritis. The increase in IL-1ra mRNA was more sustained than that of IL-1 beta mRNA. In situ hybridization showed that IL-1 beta mRNA increased diffusely within glomeruli, while IL-1ra mRNA was expressed more discretely. Expression of these mRNA in noninflamed tissues, spleens and lungs, was different, particularly increase in IL-1ra mRNA was more substantial than that of IL-1 beta. These observations suggest that differential expression of IL-1ra and IL-1 beta might focus inflammation in glomeruli while protecting more distant sites. They also raise the possibility of reducing glomerular injury by therapeutic measures that upregulate glomerular synthesis of IL-1ra while reducing that of IL-1 beta.     

西藏藏族人群白细胞介素1受体拮抗剂基因多态性

目的:研究白细胞介素-1受体拮抗剂(IL-1Ra)在西藏藏族健康人群中的分布特点,并与其他不同人群进行比较.方法:采用PCR的方法,对125名西藏拉萨市藏族人群IL-1Ra基因的可变数目串联重复序列多态性进行检测,计算其基因型频率和等位基因频率,并结合文献与其他不同人群进行比较分析.结果:西藏藏族人群IL-1Ra位点基因型以A1/A1纯合子型最为多见(频率为90.40%),A1/A2杂合子型次之(频率为9.60%),A2/A2纯合子型未检测到;其等位基因分布也是以A1等位基因最为多见 (频率为95.20%),其次为A2等位基因(频率为4.80%).西藏藏族人群的等位基因频率分布与美国人、德国人、非洲白人差异较大,具有统计学意义.而与亚洲人群包括日本人和中国汉族差异较小.结论:西藏拉萨市藏族人群中IL-1Ra位点以A1等位基因为主,其多态性分布与其他人群之间存在明显的差异,为进一步研究IL-1Ra基因多态性与疾病的关系奠定了基础.     

Effect of treatment with interleukin-1 receptor antagonist on the development of carrageenan-induced pleurisy in the rat

Pretreatment of rats with the human interleukin-1 receptor antagonist (IL-1ra) by the subcutaneous route at –0.5 h, relative to the intrapleural injection of carrageenan (CG), suppressed the infiltration of cells into the pleural cavity of intact and adrenalectomized rats at 5 h (28 and 74% reduction in intact animals at 0.3 and 10 mg/kg, respectively). Exudate volume at 5 h was also suppressed at dosages of IL-1ra 3 mg/kg. IL-1ra was still effective as an antiinflammatory agent in the 5-h pleurisy model when administered 1 or 2 h, but not 3 h, after CG. The addition of IL-1ra to a maximally effective antiinflammatory dosage of indomethacin (5 mg/kg) resulted in further reductions of cell number and exudate volume, suggesting that the antiinflammatory effects of IL-1ra in the 5-h model were not due solely to inhibition of IL-1-induced prostaglandin biosynthesis. The antiinflammatory effects of suboptimal dosages of IL-1ra and dexamethasone, administered in combination, were essentially additive. In 24-h pleurisy, IL-1ra reduced exudate volume and PMN number after a single dosage of 10 mg/kg, subcutaneously at –0.5 h and after dosages of 3 mg/kg at –0.5 and 5 h. Additional dosages of IL-1ra (3 mg/kg) at 10 and 15 h did not further inhibit PMN accumulation. Treatment with IL-1ra did not affect macrophage accumulation in 24-h CG-induced pleurisy. IL-1ra was not active as an antiinflammatory agent in the 24-h pleurisy model after three dosages of IL-1ra (3mg/kg) at 5, 10 and 15 h.