免疫特权部位：Immune privileged sites 定义：胚胎发育过程中免疫细胞未接触过的部位，如大脑、眼球内容物、精子等。In immune privileged sites, tissue grafts can survive for extended periods of time without rejection occurring，such as Brain、Eyes、Uterus when carrying a fetus、testis (sperm)。 免疫特权：在免疫隔离部位，一直同种异型抗原的组织不诱导应答，移植物不被排斥的现象。