ABCB5-positive stem cells for LSCD therapy

用于 LSCD 治疗的 ABCB5 阳性干细胞

• 批准号: 9457457
• 负责人: NATASHA Y FRANK
• 金额: $ 48.95万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-04-01 至 2021-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9457457
• 关键词: Address; Alkalies; Allogenic; Aniridia; Autologous; Bilateral; Binding; Blindness; Boston; Burn injury; Cell Maintenance; Cell Surface Proteins; Cell Survival; Cell Therapy; Cells; Chronic; Clinical; Colon; Conjunctival Epithelium; Cornea; Corneal Diseases; Corneal Injury; Corneal Stroma; Development; Disease; Disease model; Ear; Epithelial; Eye; Genes; Genetic; Hospitals; Human; Immunodeficient Mouse; In Vitro; Inflammation; Injury; Intestines; Knockout Mice; Laboratories; Lysosomal Storage Diseases; Mechanics; Monoclonal Antibodies; Mus; Natural regeneration; Nature; Ophthalmology; Organ; Patients; Pediatric Hospitals; Procedures; Regenerative Medicine; Research; Role; Skin; Source; Stem cell transplant; Stem cells; Stomach; Stratified Squamous Epithelium; Surface; Therapeutic; Time; Tissue Transplantation; Tissues; Transplantation; Transplanted tissue; Vision; Woman; adult stem cell; clinically relevant; corneal epithelium; effective therapy; human tissue; improved; limbal; member; neovascularization; prevent; prospective; public health relevance; regenerative; repaired; self-renewal; stem cell population; stem cell therapy; success

 DESCRIPTION (provided by applicant): Many mammalian organs (skin, stomach, intestines, colon, and eye) possess a source of adult stem cells that continually replenishes their rapidly self-renewing epithelial surface. One important challenge in regenerative medicine is replacing these stem cells when they are eliminated following an injury or disease. The eye contains two highly specialized stratified squamous epithelia- the conjunctival epithelium and the corneal epithelium. A healthy corneal epithelium is essential for maintaining a clear cornea and normal vision. The limbus contains a small subpopulation of rare limbal stem cells (LSC) that continually repopulates the corneal epithelium. Patients with limbal stem cell deficiency (LSCD) are unable to regenerate the corneal epithelium, resulting in "conjunctivalization" of the corneal stroma that triggers neovascularization, chronic inflammation, and ultimately blindness due to an irreversibly opaque cornea. Several approaches have been used to replace LSC by transplanting limbal tissue or ex vivo expanded limbal cells. These procedures have obtained some success, mainly using autologous limbal tissue from patients with unilateral LSCD. Patients with bilateral LSCD have no source of autologous LSC and much less success was observed with allogeneic limbal tissue transplants. However, success of all these procedures was severely limited by the inability to prospectively identify and purify LSC. This problem was recently addressed by a new collaborative research group from the departments of: Ophthalmology, Genetics, and Transplantation Research (Mass Eye & Ear, Brigham & Women's Hospital and Boston Children's Hospital) that comprises the three PIs of this proposal, who discovered that the ABCB5 gene, a new member of the ATP-binding cassette (ABC) superfamily of active transporters, is expressed by stem cells of the limbus in both mouse and human tissues. Normal function of ABCB5+ LSC is required for corneal development and repair, through critical roles in stem cell maintenance and survival, and knockout mice that lack ABCB5 do not develop a fully differentiated mature corneal epithelium. Importantly, ABCB5 is a cell surface protein and specific monoclonal antibodies developed by the laboratories of Co-PIs Drs. M. Frank and N. Frank are capable of isolating pure ABCB5-positive cells from the limbus. Transplantation of purified human ABCB5+ (but not ABCB5-) LSC onto the corneal stroma of immunodeficient mice with induced LSCD restored the corneal epithelium, indicating that this purified LSC population has the potential to significantly improve therapy for corneal disease associated with LSCD. The current application builds upon these results to address the important challenges that prevent successful stem cell therapy for patients with unilateral or bilateral LSCD. Our overall hypothesis is that ABCB5+ stem cells from the limbus can be isolated and expanded ex vivo as a source of stem cells to regenerate the corneal epithelium when transplanted to recipients with either a unilateral or bilateral LSCD.

 描述(申请人提供)：许多哺乳动物器官(皮肤、胃、肠、结肠和眼睛)拥有成体干细胞来源，不断补充其快速自我更新的上皮表面。再生医学中的一个重要挑战是当这些干细胞在受伤或疾病后被消除时替换它们。眼睛含有两个高度特化的复层鳞状上皮--结膜上皮和角膜上皮。一个健康的角膜上皮对于保持透明的角膜和正常的视力是必不可少的。角膜缘含有一小部分稀有的角膜缘干细胞(LSC)，它们不断地重新填充角膜上皮。角膜缘干细胞缺乏症(LSCD)患者无法再生角膜上皮，导致角膜基质结膜化，引发新生血管、慢性炎症，最终由于不可逆转的不透明角膜而失明。通过移植角膜缘组织或体外扩增的角膜缘细胞，已有几种方法用于替代LSC。这些手术已经取得了一些成功，主要使用了单侧LSCD患者的自体角膜缘组织。双侧LSCD的患者没有自体LSC来源，同种异体角膜缘组织移植的成功率要低得多。然而，由于不能前瞻性地识别和纯化LSC，所有这些程序的成功都受到严重限制。最近，来自眼科、遗传学和移植研究部门(大众眼耳、布里格姆妇女医院和波士顿儿童医院)的一个新的协作研究小组解决了这个问题，该小组包括该提案的三个PI，他们发现ABCB5基因是ATP结合盒(ABC)超家族活跃转运蛋白的新成员，在小鼠和人类组织中均由角膜缘干细胞表达。ABCB5+LSC的正常功能是角膜发育和修复所必需的，通过在干细胞维持和生存中发挥关键作用，而缺乏ABCB5的基因敲除小鼠不会发育出完全分化的成熟角膜上皮。重要的是，ABCB5是一种细胞表面蛋白，由Co-Pis博士M.Frank和N.Frank的实验室开发的特异性单抗能够从角膜缘分离出纯ABCB5阳性细胞。将纯化的人ABCB5+(但不是ABCB5-)LSC移植到诱导LSCD的免疫缺陷小鼠的角膜基质上，恢复了角膜上皮，表明这种纯化的LSC群体有潜力显著改善与LSCD相关的角膜疾病的治疗。目前的应用建立在这些结果的基础上，以解决阻碍单侧或双侧LSCD患者成功进行干细胞治疗的重要挑战。我们的总体假设是，来自角膜缘的ABCB5+干细胞可以在体外分离和扩增，作为干细胞的来源，当移植到患有单侧或双侧LSCD的受者身上时，可以再生角膜上皮。