移植免疫2013 课件.ppt

宿主免疫功能低下； 移植物含足够免疫活性细胞； 识别受者MHC抗原、mH抗原； 产生针对宿主组织器官损伤； 主要见于异基因骨髓移植。 Complications of Allogeneic BM Transplants Graft versus host disease Immunologically competent cells from donor Affects liver, skin, gut (jaundice, rash, diarrhea) Acute or chronic Graft versus leukemia effect may be beneficial Rejection of allogeneic marrow cells. Acute GVHR 移植物抗白血病效应Graft versus leukemia effect BMT(同卵双生，自体移植）:无GVHD，高复发率。 Allo-BMT:复发率明显减少。 NK cells express inhibitory receptors that are specific for MHC class I alleles . In humans these molecules are known as Killer Immunoglobulin-like Receptors (KIRs). 移植物NK细胞杀伤受者残留肿瘤细胞 KIR 基因具有高度的群体遗传多样性，主要表达于NK 细胞,T 细胞亚群的细胞膜表面. KIR：HLA-I 分子形成受体：配体关系.主要产生抑制信号，调节NK 细胞的活化 HLA genes are located on chromosome at loci KIR genes are located at 供受体可能出现HLA相同，而KIR 不合的情况. 相应KIR受体分子或HLA-I配体分子的缺如，将改变NK 活化阈值. Lysis Lysis leukemia DC NK DC DC NK NK Donor alloreactive NK cells Lysis T T T Kill recipient APCs = protection from GvHD Kill recipient T cells = improved engraftment Kill leukemia = GvL effect NK Cells for Stem Cell Transplantation Alloreactive NK cells could be deliberately infused to prevent leukemic relapses. Alloreactive NK cells kill the host dendritic cells (DCs). Removal of DCs prevents the presentation of host antigens to graft T cells which is the crucial step in initiating GvH reactions. Immune privilege in the cornea Keratoplasty is the oldest and one of the most successful forms of solid tissue transplantation. Does not require the aid of tissue typing or systemic immunosuppressive drugs. Contributing factors Expression of MHC class I molecules is markedly reduced . There is no constitutive expression of MHC class II molecules . Lacks both blood and lymph vessels. Lacks bone marrow-derived antigen-presenting cells (APC). 第3节 移植排斥反应的防治原则 Methods of Increasing Graft Survival Screening of preformed allo-antiboby. ABO blood groups Panel reactive antibody HLA matching. Crucial for Allo-BMT SNPs typing