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（由申请人提供）：许多哺乳动物器官（皮肤、胃、肠、结肠和眼睛）都拥有成体干细胞来源，可以不断补充其快速自我更新的上皮表面。再生医学的一个重要挑战是当这些干细胞因受伤或疾病而被消除时进行替换。眼睛含有两种高度特化的复层鳞状上皮——结膜上皮和角膜上皮。健康的角膜上皮对于维持清晰的角膜和正常视力至关重要。角膜缘含有一小部分罕见的角膜缘干细胞（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”，从而引发新生血管形成、慢性炎症，并最终因角膜不可逆地混浊而失明。已使用多种方法通过移植角膜缘组织或离体扩增的角膜缘细胞来替代 LSC。这些手术已经取得了一些成功，主要使用单侧 LSCD 患者的自体角膜缘组织。双侧 LSCD 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，由于无法前瞻性地识别和纯化 LSC，所有这些程序的成功受到严重限制。最近，来自眼科、遗传学和移植研究部门（麻省眼耳科、布莱根妇女医院和波士顿儿童医院）的一个新的合作研究小组解决了这个问题，该研究小组由该提案的三个 PI 组成，他们发现 ABCB5 基因是主动转运蛋白 ATP 结合盒 (ABC) 超家族的新成员，由干细胞表达 小鼠和人体组织中的角膜缘。 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存活中发挥关键作用，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是由Co-PIs Drs.实验室开发的细胞表面蛋白和特异性单克隆抗体。 M. Frank 和 N. Frank 能够从角膜缘分离纯 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 群体有可能显着改善与 LSCD 相关的角膜疾病的治疗。目前的应用以这些结果为基础，旨在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，当移植到单侧或双侧 LSCD 的受体时，来自角膜缘的 ABCB5+ 干细胞可以作为干细胞来源进行离体分离和扩增，以再生角膜上皮。