同种移植排斥
中文名称
通路描述
同种移植排斥是受者对供体组织表达的异种抗原产生的同种免疫反应的后果。器官同种移植后，存在两种抗原呈递途径。在直接途径中，受者 T 细胞反应于供体细胞表面表达的完整异种 MHC 分子。该途径可激活宿主 CD4 或 CD8 T 细胞。相比之下，供体 MHC 分子（以及所有其他蛋白）从移植体脱落，可被受者 APC 摄取，并在自 MHC 分子背景下呈递给受者 T 细胞——即间接途径。这种呈递主要激活 CD4 T 细胞。只有能直接识别供体 MHC 分子的 T 细胞才能对移植细胞进行直接细胞毒性攻击。尽管如此，具有间接异种特异性的 T 细胞可通过激活巨噬细胞，导致组织损伤和纤维化，并且可能对于发展对移植的异种抗体反应也很重要。
英文描述
Allograft rejection is the consequence of the recipient's alloimmune response to nonself antigens expressed by donor tissues. After transplantation of organ allografts, there are two pathways of antigen presentation. In the direct pathway, recipient T cells react to intact allogeneic MHC molecules expressed on the surface of donor cells. This pathway would activate host CD4 or CD8 T cells. In contrast, donor MHC molecules (and all other proteins) shed from the graft can be taken up by host APCs and presented to recipient T cells in the context of self-MHC molecules - the indirect pathway. Such presentation activates predominantly CD4 T cells. A direct cytotoxic T-cell attack on graft cells can be made only by T cells that recognize the graft MHC molecules directly. Nontheless, T cells with indirect allospecificity can contribute to graft rejection by activating macrophages, which cause tissue injury and fibrosis, and are also likely to be important in the development of an alloantibody response to graft.
所含基因
39 个基因