SHIP and Immunoregulatory Cell Function

描述(由申请人提供)：我们以前证明SHIP表达是异基因骨髓移植排斥反应所必需的(1)和限制这种移植用途的GvHD。(1，2)我们最近已经证明，在异基因BMT前一周诱导SHIP缺乏足以保护受者免受急性GvHD的影响。(3)宿主抗原提呈细胞(APC)负责触发同种异体T细胞反应(4)，介导GVHD。(5)SHIP-/-小鼠外周淋巴器官中髓系抑制细胞(MySC)的显著扩增拮抗APC启动的异基因T细胞反应(2，3)。我们最近发现纯化的Ship-/-MySC比WT MySC具有更强的抑制能力。(3)此外，我们还发现在胚系SHIP缺陷小鼠和诱导性SHIP缺陷小鼠中Treg细胞数量和功能增加。我们推测，在SHIP缺陷的移植受者中，MySC和/或Treg细胞功能的增强可以保护他们免受GvHD的影响，并可能减少固体器官移植排斥反应。我们最近建立了髓系细胞和T细胞的谱系特异性SHIP缺失模型。我们现在将确定髓系或T细胞限制性消融移植受者SHIP表达是否足以消除急性移植物抗宿主病(目标1)。最近建立了可诱导的FLOX/FLOX Ship缺失模型(MxCreSHIP)，并证明这是一个有效的系统，在该模型中我们可以在清髓性移植中保护成年受者免受GvHD的影响，现在我们将通过其他异基因骨髓移植程序来确定诱导Ship缺陷是否也对GvHD具有保护作用(目标2)。在目标3中，我们将使用MX-CreSHIP模型和SHIP的RNAi靶向来确定诱导性SHIP缺陷是否可以提高同种异体器官移植的成功率。我们还开发了RNAi方法来可逆地抑制体内SHIP的表达。针对SHIP表达的RNAi靶向也将在目标2中进行测试，以了解其保护受体免受GvHD的能力，并在目标3中确定其是否可以促进实体器官移植的植入。具体目标是：目标1：确定宿主保护GvHD所需的SHIP缺陷细胞谱系。目的2：明确船体缺陷可用于促进异基因骨髓移植的方式。目的3：确定船舶缺陷是否能促进同种异体器官移植。公共卫生相关性我们相信，这些研究将证明，关闭一个特定的基因可以防止移植的骨髓和与受者不匹配的器官发生排斥反应。此外，这些研究将确定接受这些不匹配的移植所需的免疫细胞类型。

DESCRIPTION (provided by applicant): We previously demonstrated that SHIP expression is necessary for rejection of allogeneic BM grafts(1) and the GvHD that limits the utility of such transplants.(1,2) We have recently shown that induction of SHIP-deficiency for a one week period prior to allogeneic BMT is sufficient to protect a recipient from acute GvHD.(3) Host antigen presenting cells (APC) are responsible for triggering allogeneic T cell responses(4) that mediate GVHD.(5) A profound expansion of Myeloid Suppressor Cells (MySC) in the peripheral lymphoid organs of SHIP-/- mice antagonizes APC priming of allgeneic T cell responses (2,3). We have recently shown that purified SHIP-/- MySC have greater suppressive capacity than WT MySC.(3) In addition, we have shown that Treg cell numbers and function are increased in germline SHIP-deficient mice and mice with induced SHIP- deficiency. We hypothesize then that increased MySC and/or Treg cell function in SHIP-deficient transplant recipients protects them from GvHD and may also reduce solid organ allograft rejection. We have recently established lineage-specific SHIP deletion models for both myeloid cells and T cells. We will now determine whether myeloid- or T cell-restricted ablation of SHIP expression in transplant recipients is sufficient to abrogate acute GvHD (Aim 1). Having recently established an inducible flox/flox SHIP deletion model (MxCreSHIP ) and demonstrated that this is an effective system in which we can protect adult recipients from GvHD in a myeloablative transplant, we will now determine whether induced SHIP-deficiency is also protective from GvHD with other allogeneic BMT procedures (Aim 2). In Aim 3, we will use the MX-CreSHIP model and RNAi targeting of SHIP to determine whether induced SHIP deficiency can enhance the success of allogeneic organ transplantation. We have also developed RNAi approaches to reversibly inhibit SHIP expression in vivo. RNAi targeting of SHIP expression will also be tested in Aim 2 for its ability to protect recipients from GvHD and in Aim 3 to determine if it can facilitate engraftment of solid organ allografts. The Specific Aims are: Aim 1: Define the SHIP-deficient cell lineages required for host protection from GvHD. Aim 2: Define the manner in which SHIP-deficiency can be used to enhance allogeneic BM transplantation. Aim 3: Determine whether SHIP-deficiency can facilitate the transplantation of allogeneic organ grafts. PUBLIC HEALTH RELEVANCE We believe these studies will demonstrate that turning off one specific gene can prevent the rejection of transplanted bone marrow and organs that are not matched to the recipient. In addition, these studies will identify the types of immune cell types required for acceptance of these unmatched transplants.