Heparin-mimetic sulfated oligoxylan inhibitors of malaria parasites

疟疾寄生虫的肝素模拟硫酸化寡聚木聚糖抑制剂

• 批准号: 7968641
• 负责人: AUDREY L STONE
• 金额: $ 5.72万
• 依托单位: EUNICE KENNEDY SHRIVER NATIONAL INSTITUTE OF CHILD HEALTH & HUMAN DEVELOPMENT
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7968641
• 关键词: Address; Agreement; Ally; Anti-malarial drug resistance; Anticoagulants; Antimalarials; Antithrombins; Biological Assay; Biological Models; Biopolymers; CYP1A1 gene; Calculi; Cells; Cerebral Malaria; Cessation of life; Charge; Child; Clinical; Clinical Research; Confidentiality; Culicidae; Data; Development; Disease; Dose; Endothelium; Erythrocytes; Family; Fractionation; GAG Gene; Glucuronic Acids; Glycosaminoglycans; Goals; Growth; HIV Infections; HIV-1; Health Sciences; Hemorrhage; Heparin; Heparitin Sulfate; Hepatocyte; Human; Immunity; In Vitro; Incidence; Inorganic Sulfates; Invaded; Keratan Sulfate; Knowledge; Lead; Libraries; Life; Ligands; Maintenance; Malaria; Malaria Vaccines; Medical; Methods; Microcirculation; Molecular; Molecular Conformation; Nature; Parasite resistance; Parasites; Patients; Personal Satisfaction; Pharmaceutical Preparations; Pharmacologic Substance; Physiological; Plasmodium falciparum; Preparation; Preventive; Process; Property; Proteins; Public Health; Reporting; Research; Role; Solutions; Specificity; Sporozoites; Structure; Symptoms; System; Techniques; Testing; Thrombin; Tissues; Toxic effect; United States National Institutes of Health; Unspecified or Sulfate Ion Sulfates; Vaccine Design; Vaccines; Variant; Virulent; Virus; Xylans; Xylose; base; biological systems; combinatorial; density; dosage; drug development; inhibitor/antagonist; mimetics; mimicry; novel; pathogen; polysulfated glycosaminoglycan; pre-clinical; prevent; programs; receptor; sugar

The initial infective process of the malaria parasite in humans is between the invading parasite and hepatocytes of the host. In several studies, the portal for this invasion has implicated the heparin/heparan sulfate (H/HS) receptor systems. Heparin also inhibits the rosetting and cytoadhesion of parasitized Plasmodium falciparum erythrocytes (PfRBC) to normal RBC and the endothelium, and clears blockage of the microcirculation which ameliorates life-threatening symptoms of cerebral malaria when administered in children. - Early on, at NIH, we discovered that heparin assumed helical structures in solution. We classified the various sulfated glycosaminoglycan biopolymers (GAG, mucopolysaccharides) on the basis of the specificity of their optically active structures and demonstrated (AL Stone 1963/4 Biopolymers 2/3) that H/HS (and keratosulfate) comprise a Class of GAGs, separate from other GAG types. They are multifunctional physiological modulator biopolymers. They are found in most tissues of the body where they not only govern the level of activity/function of numerous normal proteins and cell systems, but they also seem to serve as receptors for various human pathogens in a mechanism(s) that needs further elucidation. -Malaria ranks in the top three deadliest diseases globally (more than 300 million clinical cases per year). 1-3% of the Pf parasites are highly virulent, causing severe and cerebral malaria and the death of about 2-3 million people per year (90 % young children). There is no preventive vaccine, and malaria parasites are increasingly resistant to anti-malarial drugs. We applied our combinatorial family of heparin-mimetic S-oligoS (See HD 001315-14) in a preliminary study to characterize their in vitro inhibition capacities against malaria parasites. This revealed that the heparin-based inhibition of P. yoelii sporozoite (freshly isolated from infected mosquitoes) invasion of hepatocytes was governed by a degree of structural specificity and was concentration dependent. Two highly active library Components were identified: Component 6 (mass = 7200) and Component 11 (mass = 3700) which displayed 43 and 56 percent inhibition at 3.5 and 5 micromolar, resp. We reported early on that CP11, as well as other Components of mass less than 5000, had negligible capacity to mimic heparin's anticoagulant activation of antithrombin against thrombin (which causes the occasional bleeding toxicity when pharmaceutical heparin is administered clinically). Thus, Cp11 was selected for development of an enlarged preparation of purified Cp11 for preclinical and clinical studies was undertaken and is ongoing to insure adequate fractionation with good yield for this relatively small-sized S-OligoS Component. Importantly, last year's efforts to renew our mutual Confidentiality Agreement were realized this year, and contribution of a large lot of heparin-mimetic pharmaceutical starting material for an additional preparation of our HIV-1 fusion inhibitor, SOLIS, was transferred and received from Munich, D.R.. This will enable newly devised enlarged preparations of Components Cp11 and Cp8A/8B, as well. -Structural studies will be extended and further developed on the Cp11: E.g., Studies on a specific tetrasaccharide structural motif of three xyloses and a glucuronic acid as a branch on the xylan chain (90 percent sulfated yielding a high negative charge density) which we have demonstrated for S-OligoS H/HS mimetic Components, and obtained spectroscopic evidence indicating an increase in the number of stable motifs with increasing mass; Spectroscopic examination for presence of alternative sugar ring conformation, which was demonstrated unequivocally in the SOLIS structure. Such alternate forms induce specific distance and angle alterations in the otherwise uniform S-OligoS chain properties. Such a motif could accommodate the subtle specific variations in geometries involving sulfates that are required for mutifunctional mimicry of the heparins. Elucidation of the Cp11 structure might enable application of advanced high throughput methods in further drug development. -Recently developed statistical analysis was used by clinicians to calculate findings (Science319:1603 2006) that HIV infection in malaria endemic regions is spread at a rate 8 percent higher than in other regions where HIV-AIDS is on the rise, and vise-versa, due to an unexplained vullnerability of either patient to the second pathogen. We had suggested previously that co-treatment of malaria and HIV-AIDS would be feasible because of the close similarity in the physicochemical proerties of the respective S-oligoS inhibitors. The preliminary studies on the combined dosing of the Cp11 and SOLIS (S-OligoS malaria parasite and HIV-1 inhibitors, resp.) in vitro indicated a decrease in SOLIS capacity to protect against fusion between the virus and target CMESS (CD4 human line). Given the complexity of the biological systems which may be involved, the data are currently interpreted based on various biological models to generate appropriate studies which will be conducted with the Cp11 to elucidate this interpathogenesis. the S-OligoS structure contains a tetrasaccharide motif motif of three xyloses and a glucuronic acid as a branch on the xylan chain i.e., -D-glucuronyl-alpha 1,2 beta 1,4 D-(xylyl)3 with one third or less of the GlcA being O-methylated. The sugars are within 90 percent sulfated yielding a high negative charge density. Such a motif could accommodate the subtle variations in geometries involving sulfates that are required for mutifunctional mimicry of the heparins.

人类疟原虫寄生虫的最初感染过程在宿主的入侵寄生虫和肝细胞之间。在几项研究中，该入侵的门户涉及肝素/肝素硫酸盐（H/HS）受体系统。肝素还抑制了寄生的恶性疟原虫红细胞（PFRBC）对正常RBC和内皮细胞的玫瑰胶和细胞粘附，并在儿童服用时会减轻微循环的阻塞，从而清除脑危害症状的症状。 - 早期，在NIH，我们发现肝素在溶液中采用了螺旋结构。我们根据其光学活性结构的特异性对各种硫酸化的糖胺聚糖生物聚合物（GAG，粘多糖）进行了分类（Al Stone 1963/4生物聚合物2/3），该结构（Al Stone 1963/4生物聚合物2/3）将H/hs（和角膜硫酸盐）与其他GAG类型分开。 它们是多功能的生理调节剂生物聚合物。它们在人体的大多数组织中发现，它们不仅控制着许多正常蛋白质和细胞系统的活性/功能水平，而且它们似乎还可以作为需要进一步阐明的机制中各种人类病原体的受体。 - 马拉里亚（Malaria）在全球最致命的三种疾病中排名（每年超过3亿个临床病例）。 1-3％的PF寄生虫具有高度毒性，导致严重和脑疟疾，每年约有2-3万人死亡（90％的幼儿）。没有预防性疫苗，疟疾寄生虫越来越对抗疟疾药物具有抗性。我们在一项初步研究中应用了肝素模拟S-Oligos（参见HD 001315-14）的组合家族，以表征其对疟疾寄生虫的体外抑制能力。 这表明，基于肝素的P. yoelii孢子岩（从感染的蚊子中分离出来）侵袭肝细胞的抑制作用受到一定程度的结构特异性的控制，并且浓度取决于浓度。确定了两个高度活跃的文库组件：组件6（质量= 7200）和组分11（质量= 3700），在3.5和5 micrololar时显示43％和56％的抑制作用。 我们在CP11的早期以及其他质量小于5000的成分的早期报道，可以忽略地模仿肝素对抗凝血酶对凝血酶的抗凝剂激活（在临床上给药时偶尔会导致药物肝素时偶尔出血毒性）。 因此，选择了CP11进行临床前研究和临床研究的扩大制备纯化的CP11，并正在进行为这种相对较小的S-Oligos成分提供良好产量的足够分馏。 重要的是，今年实现了去年续签我们相互保密协议的努力，以及许多肝素模拟药物的起始材料的贡献，以额外准备我们的HIV-1融合抑制剂Solis，并从慕尼黑转移并从D.R. - 结构研究将在CP11上进行扩展并进一步开发：质量增加；光谱检查是否存在替代糖环构象，这在Solis结构中明确证明了这一点。 这种替代形式在原本均匀的S-Oligos链特性中诱导特定的距离和角度变化。 这样的基序可以适应涉及硫酸硫酸盐的几何形状的细微特异性变化，而硫酸盐是肝素模仿所需的。 阐明CP11结构可能使高级高通量方法在进一步的药物开发中应用。 -Recently developed statistical analysis was used by clinicians to calculate findings (Science319:1603 2006) that HIV infection in malaria endemic regions is spread at a rate 8 percent higher than in other regions where HIV-AIDS is on the rise, and vise-versa, due to an unexplained vullnerability of either patient to the second pathogen. 我们以前曾建议，由于相应的S-Oligos抑制剂的物理化学方面的相似性，疟疾和HIV-AID的共同治疗是可行的。 对CP11和SOLIS（S-橄榄虫寄生虫和HIV-1抑制剂）的联合剂量的初步研究，体外表明，索利斯能力降低了可防止病毒与靶CMESS（CD4人类系）之间融合的能力。 鉴于可能涉及的生物系统的复杂性，目前根据各种生物学模型来解释数据，以生成适当的研究，这些研究将与CP11进行，以阐明这种互助作用。 S-Oligos结构包含三种木糖和葡萄糖酸的四糖基序，作为Xylan链上的分支，即-d-葡萄糖苷-Alpha 1,2ββ1,4d-（xylyl）3，三分之一或更少的glca glca被蛋白甲基化。糖在90％的硫酸盐之内，产生高电荷密度。这样的基序可以适应涉及肝素模仿所需的硫酸盐的几何形状的细微变化。