Immunotherapy using NK cells to promote engraftment

描述(申请人提供)：使用骨髓移植(BMT) 然而，对于各种疾病的治疗，急性毒性 与骨髓移植中的条件反射过程相关联，导致了 非清髓性条件作用疗法。宿主效应细胞对BMC移植物的排斥反应仍然是一个重要的问题。自然杀伤(NK)细胞是 自发介导对转化的或病毒感染的细胞的杀伤 MHC-不受限制的方式。我们之前已经证明，激活的NK细胞 供体类型的细胞可促进小鼠异基因骨髓移植后的供体植入。 我们现在建议评估NK细胞转移的效果 非清髓性模型，以确定是否激活了NK细胞，或者作为整体 或通过使用纯化的亚群，可以促进供者的BMC 嫁接。我们假设激活供者类型的NK细胞，特别是 当纯化的或具有抑制性受体的那些(Ly-49在 小鼠)阻断，可以消除或抑制宿主同种异体反应细胞的到来 与它们接触，从而获得更强的植入能力 随后的供者骨髓细胞。为了实现这一目标，我们制定了4个具体目标： 特定目标1将评估供者NK细胞转移对促进 使用同种异体菌株组合和模型的供体嵌合体 减少全身照射(TBI)作为一种调理方案。 对宿主NK和T细胞介导的排斥反应通路的影响将是 使用体外和体内试验进行评估。捐献者嵌合体的程度， 移植物抗宿主病的证据和耐受诱导的特异性将被评估。 特异性目标2将确定特定的Ly-49 NK细胞亚群的转移 将增强捐赠者NK细胞阻止后续骨髓的能力 拒绝。NK细胞亚群携带特异性Ly-49抑制受体 主机MHC将被移除，从而允许传输的 增加宿主效应细胞的数量，从而提高植入率。特定的 目的3将使用针对Ly-49成员的各种抗体的F(ab？)2片段来阻断与MHC抑制性受体的相互作用。 特定目标4将破译NK细胞抑制宿主的机制 抵抗。各种免疫抑制细胞因子的中和抗体 (即转化生长因子-β)和使用基因敲除小鼠(即穿孔素)作为NK的来源 细胞将被用来确定细胞因子相对于裂解途径的作用 NK细胞的免疫抑制作用。这些研究应该会导致 提高非清髓疗法的疗效，并开发一种方法 诱导耐受性。

DESCRIPTION (provided by applicant): Bone marrow transplantation (BMT) is used for the treatment of a variety of disorders, however, the acute toxicities associated with the conditioning procedure in BMT has led to the emergence of non-myeloablative conditioning therapies. Rejection of the BMC graft by host effector cells remains a significant concern. Natural killer (NK) cells are cells that spontaneously mediate the killing of transformed or virally infected cells in a MHC-unrestricted manner. We have previously shown that activated NK cells of donor-type can improve donor engraftment after allogeneic BMT in mice. We now propose to assess the effects of NK cell transfer using a non-myeloablative model to ascertain if activated NK cells, either as whole populations or through the use of purified subsets, can promote donor BMC engraftment. We hypothesize that activated NK cells of donor-type, particularly when either purified or those who have their inhibitory receptors (Ly-49 in the mouse) blocked, can eliminate or suppress host alloreactive cells that come into contact with them resulting in greater engraftment capability of subsequent donor BMC. Toward this goal we have developed 4 Specific Aims: Specific Aim 1 will assess the effects of donor NK cell transfer on promoting donor chimerism using allogeneic strain combinations and models involving decreasing amounts of total body irradiation (TBI) as a conditioning regimen. The effect on both host NK and T cell-mediated rejection pathways will be assessed using both in vitro and in vivo assays. Extent of donor chimerism, evidence for GVHD, and specificity of tolerance induction will be assessed. Specific Aim 2 will determine if transfer of specific Ly-49 NK cell subsets will enhance the ability of the donor NK cells to prevent subsequent marrow rejection. NK cell subsets bearing Ly-49 inhibitory receptors specific for the host MHC will be removed allowing for greater reactivity of the transferred population for the host effector cells and thus improve engraftment. Specific Aim 3 will use F(ab?)2 fragments of various antibodies specific for Ly-49 members to block the interaction with the inhibitory receptors with MHC. Specific Aim 4 will decipher the mechanism by which NK cells inhibit host resistance. Neutralizing antibodies to various immunosuppressive cytokines (i.e. TGF-beta) and the use of knockout mice (i.e. perforin) as a source of NK cells will be used to determine the role of cytokines versus lytic pathways in the immunosuppressive effect of NK cells. These studies should result in improving the efficacy of non-myeloablative therapies and to develop a means to induce tolerance.