MODULATING THE LOCAL IMMUNE MICROENVIRONMENT TO PROLONG ALLOGRAFT SURVIVAL

调节局部免疫微环境以延长同种异体移植物的存活

• 批准号: 6301970
• 负责人: JEFFREY R MORGAN
• 金额: $ 18.8万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-01 至 2000-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6301970
• 关键词: CD28 molecule; SCID mouse; T lymphocyte; apoptosis; cell differentiation; cell proliferation; disease /disorder model; epidermal growth factor; gene expression; gene therapy; genetic manipulation; genetic transduction; homologous transplantation; human tissue; immunosuppression; interleukin 10; keratinocyte; leukocyte activation /transformation; nonhuman therapy evaluation; skin transplantation; tissue /cell culture; transfection /expression vector; transforming growth factors; transplant rejection; wound healing

Unlike allografts or other solid organs or tissues, the availability of allogeneic keratinocytes is not the major problem or current limitation. Allogeneic keratinocytes are readily available from numerous tissue sources; moreover, these cells have tremendous growth potential. Estimates that are that a 1cm2 biopsy can be expanded to 1m2 of cultured epithelium within 30 days. The challenge is to develop strategies that facilitate the long term survival of allografts of cultured keratinocytes without the use of systemic immunosuppressive drugs, which depress the entire immune system, thereby increasing the risk of cancer and infections. Strategies are needed that achieve immunosuppression which is local and confined to the transplanted organ and/or immunosuppression, which induces donor-specific hypo-responsiveness or even donor-specific tolerance. These needs are especially relevant to the skin. Although the surgical procedure of skin transplantation is relatively easy, immunological barriers to the acceptance of skin allografts are formidable, thus making skin allografts perhaps the most difficult organ to transplant. It is our hypothesis that local immunosuppression and/or donor specific tolerance for grafts of cultured keratinocytes can be achieved through the over-expression of one or more immunosuppressive factors (FasL, CTLA-4, IL-10) by the keratinocytes of the graft. To test this hypothesis, we propose to genetically modify keratinocytes with recombinant retroviruses expressing these immunosuppressive factors and to evaluate the survival of these modified allogeneic cells in animal models of allograft rejection. Modified murine keratinocytes will be tested in 2 donor-recipient models with increasing levels of mismatch and severity of allograft response; mismatch of class I and mismatch of class I, and mismatch of class I, II, and minor antigens. Modified human keratinocytes will be tested in a model of human allograft rejection by grafting keratinocytes to immunodeficient mice which have been engrafted with human immune cells and are competent to reject an allograft. In each of these models, we will gain a better understanding of allograft rejection by determining if immunosuppressive factor expression alters the kinetics and cell populations involved in the response. We will also determine if this regimen induces donor-specific tolerance. In addition to providing new information on the pathways of allograft rejection, these studies may lead to the development of a "universal" epidermal allograft for numerous applications in gene therapy.

与同种异体移植物或其他实体器官或组织不同， 同种异体角质形成细胞不是主要问题或目前的限制。 同种异体角质形成细胞可从许多组织中获得 此外，这些细胞具有巨大的生长潜力。 据估计，1 cm 2的活检可以扩大到1 m2的培养 30天内的上皮细胞。挑战在于制定战略， 促进培养的同种异体移植物的长期存活， 角质形成细胞而不使用全身免疫抑制药物， 抑制整个免疫系统，从而增加患癌症的风险 和感染需要采取免疫抑制策略 其是局部的并且局限于移植的器官，和/或 免疫抑制，诱导供体特异性低反应性，或 甚至是捐赠者的特异性耐受性。这些需要特别关系到 皮肤虽然皮肤移植的外科手术是 相对容易，免疫屏障接受皮肤 同种异体移植是可怕的，因此使皮肤同种异体移植可能是最 难以移植的器官 我们的假设是，局部免疫抑制和/或供体特异性 对培养的角质形成细胞移植物的耐受性可以通过 一种或多种免疫抑制因子（FasL， CTLA-4、IL-10）。为了验证这一 假设，我们建议用以下基因修饰角质形成细胞： 表达这些免疫抑制因子的重组逆转录病毒， 为了评估这些修饰的同种异体细胞在动物中的存活， 同种异体移植排斥模型。修饰的鼠角质形成细胞将 在2个捐助者-接受者模式中进行了检验，错配程度增加 和同种异体移植反应的严重程度; I类错配和 I类，以及I类、II类和次要抗原的错配。修饰的人 角质形成细胞将在人同种异体移植排斥模型中进行测试， 将角质形成细胞移植到免疫缺陷小鼠， 与人类免疫细胞结合并有能力排斥同种异体移植物。在 每一种模型，我们都将更好地了解同种异体移植物 通过确定免疫抑制因子表达是否改变 动力学和参与反应的细胞群体。我们还将 确定这种方案是否诱导供体特异性耐受。此外 为同种异体移植排斥反应的途径提供新的信息， 这些研究可能导致“通用”表皮的发展 同种异体移植物在基因治疗中有许多应用。