Nagata S, Cohen N
Eur J Immunol. 1983 Jul;13(7):541-5. doi: 10.1002/eji.1830130705.
Thymectomy of very young Xenopus larvae abrogated in vitro proliferative responses to phytohemagglutinin (PHA) and allogeneic leukocytes. Thymectomized (Txd) frogs, however, still rejected first-set skin allografts chronically and second-set grafts (but not third-party grafts) more rapidly. The specific second-set rejection reaction by Txd frogs was transferable in vivo to secondary Txd hosts (with major histocompatibility complex identical to the cell donor) by the subcutaneous injection of a mixture of splenic and peripheral blood leukocytes. Spleen cells used in this adoptive transfer experiment (i.e., immune cells) were responsive to allogeneic cells from the original donor strain as well as from unrelated donors in mixed leukocyte culture in vitro but were still unreactive to PHA. The results are consistent with an extrathymic pathway of alloreactive cell differentiation in this species, although the physiological significance of such a pathway is not clear.
对非常年幼的非洲爪蟾幼体进行胸腺切除，可消除其对植物血凝素（PHA）和同种异体白细胞的体外增殖反应。然而，胸腺切除（Txd）的青蛙仍能长期排斥首次移植的皮肤同种异体移植物，且对第二次移植的移植物（但不包括第三方移植物）排斥反应更快。Txd青蛙的特异性二次排斥反应可通过皮下注射脾脏和外周血白细胞的混合物，在体内转移至二次Txd宿主（其主要组织相容性复合体与细胞供体相同）。在该过继转移实验中使用的脾细胞（即免疫细胞），在体外混合白细胞培养中对来自原始供体菌株以及无关供体的同种异体细胞有反应，但对PHA仍无反应。这些结果与该物种中同种异体反应性细胞分化的胸腺外途径一致，尽管这种途径的生理意义尚不清楚。
