Studies in the Pathogenesis of Systemic Capillary Leak Syndrome

全身毛细血管渗漏综合征发病机制的研究

• 批准号: 10272154
• 负责人: Kirk m Druey
• 金额: $ 65.64万
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 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/10272154
• 关键词: Actins; Acute; Address; Adherens Junction; Adult; Alleles; American Association of Cancer Research; Anaphylaxis; Angiogenic Proteins; Angioneurotic Edema; Angiopoietin-2; Animal Model; Antibodies; Antigen Targeting; Antihypertensive Agents; Binding; Biological; Biological Assay; Blood; Blood Cells; Blood Vessels; Blood capillaries; CCL2 gene; CXCL10 gene; Candidate Disease Gene; Capillary Leak Syndrome; Cell Line; Child; Chromosome 6; Clinical Protocols; Collaborations; DNA sequencing; Defect; Diagnosis; Disease; Disease remission; Edema; Endothelial Cells; Endothelium; Etiology; Event; Extravasation; Flare; Functional disorder; Genes; Genetic; Goals; Growth and Development function; Hematopoietic; Histamine; Human; Hypersensitivity; Hypotension; Hypovolemia; Immune; Immunoglobulin G; Immunoglobulins; In Vitro; Inbred Strains Mice; Infection; Inflammation Mediators; Inflammatory; Interleukin-6; Intravenous Immunoglobulins; Link; Liquid substance; Literature; Maps; Mediator of activation protein; Medical; Modeling; Molecular; Monoclonal Antibodies; Monoclonal gammopathy of uncertain significance; Morbidity - disease rate; Multiple Myeloma; Mus; Mutation; Names; Nature; Odds Ratio; Oliguria; Paraproteins; Parents; Pathogenesis; Patients; Penetrance; Permeability; Phase I Clinical Trials; Plasma; Plasma Cells; Plasmacytic Leukemia; Polymorphism Analysis; Population; Predisposition; Process; Property; Protein Array; Proteins; Proteome; Protocols documentation; RNA; Rare Diseases; Reporting; Research; Rodent Model; Role; Sample Size; Sepsis; Shock; Signal Pathway; Signs and Symptoms; Single Nucleotide Polymorphism; Skin; Source; Stimulus; Stress Fibers; Susceptibility Gene; Symptoms; Syndrome; TIE-2 Receptor; Testing; Tissues; United States National Institutes of Health; Variant; Vascular Endothelial Growth Factors; Xenograft Model; anasarca; angiogenesis; attenuation; biomedical referral center; cadherin 5; chemotherapy; clinical center; cohort; cytokine; density; exome sequencing; experience; genetic analysis; genetic association; genome sequencing; genome-wide; genomic locus; immunoregulation; macromolecule; meetings; mortality; mouse model; novel; novel therapeutic intervention; pre-clinical; premalignant; receptor; response; solute; specific biomarkers; stressor; trait; transcriptome; tumor; whole genome

Immune dysregulation may contribute to the pathophysiologic findings seen in SCLS. A MGUS, a premalignant precursor to multiple myeloma (MM), is a condition characterized by a clonal plasma cell population that secretes monoclonal immunoglobulins (Ig, also referred to as a paraprotein). MGUS is detectable in a majority of SCLS cases. Several patients with SCLS in whom MGUS evolved into myeloma or plasma cell leukemia experienced fewer capillary leak episodes after chemotherapy for their hematopoietic disorder. These findings suggest that the monoclonal paraprotein from the dysregulated plasma cell population may be the direct or indirect source of the pathophysiologic findings observed. Current studies are focused on identifying the target antigen of SCLS monoclonal Ig, if any, using high-throughput protein arrays. We are also characterizing the transcriptome of blood cell RNA and the proteome of SCLS serum/plasma, both pre- and post-attack, to determine whether specific biomarkers of acute SCLS symptoms and/or etiological factors can be identified. We have now evaluated nearly 75 patients with a confirmed diagnosis of SCLS under this protocol in the last 11 years. We are the primary referral center in the U.S. for SCLS. Circulating permeability factors, vascular endothelial growth factor (VEGF), angiopoietin 2 (Angpt-2), CXCL10, CCL2, and IL-6, were elevated in episodic SCLS sera compared to remission sera. These findings suggest that angiogenic proteins and proinflammatory cytokines that induce endothelial cell (EC) hyper-permeability may contribute to transient EC barrier dysfunction around SCLS flares. The transient episodes of hypotensive shock and anasarca in SCLS are thought to arise from reversible microvascular barrier dysfunction. Application of episodic but not convalescent SCLS sera to human microvascular ECs caused vascular endothelial cadherin internalization, disruption of interendothelial junctions, actin stress fiber formation, and increased permeability in complementary functional assays. EC contraction and temporary attenuation of adherens junctions may thus permit leakage of solutes and proteins into the extravascular space during acute episodes. In fiscal year 20, we continued to study mechanisms underlying the discovery that the skin microvasculature and endothelial cell lines from SCLS patients are hyper-responsive to routine inflammatory mediators such as VEGF and histamine. Current studies are aimed at identifying molecular defects in the signaling pathways that underly these abnormalities. The role of specific gene defects in SCLS, if any, is unknown; e.g. whether the endothelium is genetically programmed for hyper-responsiveness to routine stimuli. There are no consistent familial aggregations in SCLS, and whole exome sequencing of unrelated adults with SCLS and several parent-child trios failed to reveal a uniform exotic etiology. Using Affymetrix Single Nucleotide Polymorphism (SNP) microarrays, we performed the first genome-wide SNP analysis of SCLS in a cohort of 12 disease subjects and 18 controls. From unbiased high-density mapping of single-nucleotide polymorphisms (SNPs), a small genetic interval, 3p25.3, was identified as the highest-ranking candidate susceptibility locus (p 10-6) with an odds ratio of 41. Odds ratios (7-41) and p values (10-4 and 10-6) for the top SCLS-associated variants were outsized for such a small sample size. These results imply high penetrance for a rare disease allele that remains to be identified. Currently, we are performing whole genome sequencing of DNA from patients to test the hypothesis that they are prone to exaggerated responses to otherwise mundane inflammatory stressors due to underlying genetic defect(s). In FY20, we described an original rodent model of SCLS. We identified an inbred mouse strain, SJL, which recapitulates cardinal features of SCLS, including susceptibility to histamine- and infection-triggered vascular leak. We named this trait Histamine hypersensitivity (Histh/Histh) and mapped it to Chromosome 6. Histh is syntenic to the genomic locus most strongly associated with SCLS in humans (3p25.3), revealing that the predisposition to develop vascular hyperpermeability has a strong genetic component conserved between humans and mice and providing a naturally occurring animal model for SCLS. Genetic analysis of Histh may reveal orthologous candidate genes that contribute not only to SCLS, but also to normal and dysregulated mechanisms underlying vascular barrier function more generally. Finally, we entered into a collaboration with PharmAbcine, Inc. to study a monoclonal antibody, PMC-403, which targets the Angpt2 receptor, Tie2. PMC-403 is a novel agonistic antibody that binds to human-Tie2 receptor and promotes stabilization of leaky blood vessels in tumor models in mice. The key findings were presented recently at the American Association of Cancer Research (AACR) meeting 2020, and PMC-403 is expected to enter a phase I clinical trial in 2022. We will investigate PMC-403 in the preclinical mouse model of SCLS and its effects on SCLS ECs to inflammatory mediators in vitro.

免疫失调可能导致 SCLS 的病理生理学结果。 MGUS 是多发性骨髓瘤 (MM) 的癌前前体，是一种以分泌单克隆免疫球蛋白（Ig，也称为副蛋白）的克隆浆细胞群为特征的疾病。大多数 SCLS 病例中均可检测到 MGUS。 几位 MGUS 演变为骨髓瘤或浆细胞白血病的 SCLS 患者在接受造血障碍化疗后，毛细血管渗漏事件减少。 这些发现表明，来自失调的浆细胞群的单克隆副蛋白可能是观察到的病理生理学结果的直接或间接来源。目前的研究重点是使用高通量蛋白质阵列来鉴定 SCLS 单克隆 Ig 的靶抗原（如果有）。 我们还对攻击前和攻击后的血细胞 RNA 转录组和 SCLS 血清/血浆的蛋白质组进行了表征，以确定是否可以识别急性 SCLS 症状和/或病因因素的特定生物标志物。在过去 11 年里，我们已经根据该方案评估了近 75 名确诊为 SCLS 的患者。我们是美国 SCLS 的主要转诊中心。与缓解期血清相比，阵发性 SCLS 血清中的循环渗透因子、血管内皮生长因子 (VEGF)、血管生成素 2 (Angpt-2)、CXCL10、CCL2 和 IL-6 升高。这些发现表明，诱导内皮细胞 (EC) 高渗透性的血管生成蛋白和促炎细胞因子可能导致 SCLS 耀斑周围短暂的 EC 屏障功能障碍。 SCLS 中短暂的低血压休克和全身水肿被认为是由可逆性微血管屏障功能障碍引起的。将偶发性而非恢复期 SCLS 血清应用于人微血管 EC，导致血管内皮钙粘蛋白内化、内皮间连接破坏、肌动蛋白应力纤维形成以及补充功能测定中通透性增加。因此，在急性发作期间，内皮细胞收缩和粘附连接的暂时减弱可能导致溶质和蛋白质渗漏到血管外空间。在第 20 财年，我们继续研究其背后的机制，发现 SCLS 患者的皮肤微血管系统和内皮细胞系对 VEGF 和组胺等常规炎症介质过度敏感。目前的研究旨在识别这些异常背后的信号通路中的分子缺陷。 特定基因缺陷在 SCLS 中的作用（如果有的话）尚不清楚；例如内皮细胞是否通过基因编程对常规刺激产生过度反应。 SCLS 不存在一致的家族聚集，对不相关的 SCLS 成人和几个亲子三人组的全外显子组测序未能揭示统一的外来病因。使用 Affymetrix 单核苷酸多态性 (SNP) 微阵列，我们对 12 名疾病受试者和 18 名对照者进行了首次 SCLS 全基因组 SNP 分析。根据单核苷酸多态性 (SNP) 的无偏高密度图谱，一个小的遗传区间 3p25.3 被确定为排名最高的候选易感位点 (p 10-6)，优势比为 41。优势比 (对于如此小的样本量，与 SCLS 相关的顶级变体的 p 值（10-4 和 10-6）过大。这些结果意味着有待鉴定的罕见疾病等位基因具有高外显率。目前，我们正在对患者的 DNA 进行全基因组测序，以检验以下假设：由于潜在的遗传缺陷，他们容易对普通的炎症应激源产生过度的反应。 在 2020 财年，我们描述了 SCLS 的原始啮齿动物模型。 我们鉴定了一种近交小鼠品系 SJL，它概括了 SCLS 的主要特征，包括对组胺和感染触发的血管渗漏的易感性。我们将这种性状命名为组胺超敏性 (Histh/Histh)，并将其映射到 6 号染色体。 Histh 与人类 SCLS 最密切相关的基因组位点 (3p25.3) 同线性，表明血管通透性过高的倾向具有很强的遗传性。人类和小鼠之间保守的成分，并为 SCLS 提供自然发生的动物模型。 Histh 的遗传分析可能揭示直系同源候选基因，这些基因不仅有助于 SCLS，而且还有助于更广泛的血管屏障功能的正常和失调机制。 最后，我们与 PharmAbcine, Inc. 合作研究一种单克隆抗体 PMC-403，其靶向 Angpt2 受体 Tie2。 PMC-403 是一种新型激动性抗体，可与人 Tie2 受体结合并促进小鼠肿瘤模型中渗漏血管的稳定。该关键发现最近在美国癌症研究协会（AACR）2020年会议上公布，PMC-403预计将于2022年进入I期临床试验。我们将在SCLS临床前小鼠模型中研究PMC-403及其疗效SCLS ECs 对体外炎症介质的影响。