QMS Technology to Deplete T Cell Alloreactivity

描述(申请人提供)：异基因造血干细胞移植仍然是许多恶性血液病患者的唯一治疗选择。移植物抗宿主病(GvHD)是限制造血细胞跨越组织相容性障碍移植的一个主要因素，它有效地限制了移植给少数患者，这些患者将从治疗中受益。广泛去除供者的T细胞可以消除移植物抗宿主病。然而，T细胞耗尽的一个重要后果是移植后严重而持久的T细胞免疫缺陷状态，导致严重的机会性病毒和真菌感染，显著限制了生存。移植后过继输注成熟的记忆T细胞可能会对机会性感染提供保护，并缩短免疫缺陷的时间，直到成功的免疫重建。然而，这一策略在降低T细胞耗竭移植后死亡率方面的成功，将取决于选择性地移除介导GvHD的同种异体反应性T细胞，同时保留能够对病毒和第三方抗原产生反应的大量记忆T细胞。虽然已经研究了许多方法，但耗尽同种异体反应性T细胞的程度仅限于3log，这并没有完全预防GvHD，也限制了可以输入以提高免疫力的T细胞的数量。供体T细胞体外激活不完全和/或激活细胞的无效耗竭可能导致同种异体反应性的次优耗竭。这项建议的总体目标是开发一种有效去除同种异体反应性T细胞的系统，供临床使用。具体地说，我们的目标是1)通过研究培养条件和不同抗原在激活的T细胞上选择性表达的动力学来优化激活最大数量的供者特异性T细胞的条件，作为耗竭的靶点，2)开发一种GMP级高性能免疫磁分离系统，四极磁细胞分选(QMS)，用于临床规模的激活的供体T细胞的耗竭，能够在保持同种异体反应性T细胞的3log耗竭的同时保留q&gt；80%的第三方反应性。这项建议中开发的技术应该会极大地促进过继供者T细胞疗法的临床试验的发展，以改善T细胞耗尽的不匹配干细胞移植后的免疫功能。

DESCRIPTION (provided by applicant): Allogeneic hematopoietic stem ceil transplantation remains the only curative option for many patients with hematological malignancies. Graft-versus-host disease (GvHD) is a major limitation to transplantation of hematopoeitic cells across histocompatibility barriers, and effectively limits transplantation to a minority of patients who would benefit from treatment. Extensive T cell depletion of the donor graft can eliminate GvHD. A significant consequence of T cell depletion, however, is a profound and long-lasting T cell immunodeficiency state post-transplant resulting in severe opportunistic viral and fungal infections that significantly limit survival. The adoptive infusion of mature, memory T cells post-transplant may offer protection against opportunistic infection, and shorted the period of immunodeficiency until successful immune reconstitution occurs. The success of this strategy in reducing mortality following T cell depleted transplants, however, will depend on the selective removal of alloreactive T cells that mediate GvHD, while retaining a high repertoire of memory T cells capable of reacting to viral and third party antigens. Although a number of methods have been investigated, the extent of depleting alloreactive T cell has been limited only to <3 log, which has not fully prevented GvHD and limited the number of T cells that can be infused to improve immunity. Either incomplete in-vitro activation of donor T cells with alloreactive potential and/or inefficient depletion of the activated cells likely contributes to suboptimal depletion of alloreactivity. The overall goal of this proposal is to develop a system for efficient depletion of alloreactive T cells for clinical use. Specifically, we aim to 1) Optimize the conditions for activating the maximum number of donor-specific T cells by studying culture conditions and the kinetics of different antigens expressed selectively on activated T cells for use as targets in depletion, and 2) Develop a GMP grade hiqh-performance immunomagnetic separation system, quadrupole magnetic cells sorting (QMS), for clinical scale depletion of activated donor T cells that is capable of >=3 log depletion of alloreactive T cells while retaininq >80% of third party reactivity. The technology developed in this proposal should greatly facilitate the development of clinical trials of adoptive donor T cell therapy to improve immune function following T-cell-depleted mismatched stem cell transplants.