Effects of thyroxine-driven precocious metamorphosis on maturation of adult-type allograft rejection responses in early thyroidectomized frogs.
Effects of thyroxine-driven precocious metamorphosis on maturation of adult-type allograft rejection responses in early thyroidectomized frogs.
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甲状腺素驱动的性早熟对早期甲状腺切除青蛙成年型同种异体移植排斥反应成熟的影响。
DOI：
10.1111/j.1432-0436.1988.tb00719.x
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Cohen,N
中科院分区：
文献类型：
--
作者：
Rollins-Smith,LA;Parsons,SC;Cohen,N
与成体同种异体皮肤移植的反应性模式不同，南非爪蛙幼体要么对成体主要组织相容性复合体(MHC)不同的皮肤移植物产生耐受性，要么缓慢排斥它们。幼虫无法排斥在次要组织亲和性(H)基因座(MHC相合)不相容的移植物；相反，它们变得免疫耐受。我们在此报道，早期甲状腺切除(甲状腺)幼虫被迫在甲状腺素(T4)治疗方案中早熟变态，表现出幼虫样反应，因为它们排斥微小H基因座或一种MHC单倍型的同种异体皮肤的能力与年龄匹配的完整变性后对照显著受损。在非洲爪哇正常个体发育过程中，幼体阶段淋巴细胞数量增加，变态过程中淋巴细胞数量减少，6-12月龄时淋巴细胞数量增加至成体水平。甲状腺切除和低剂量的甲状腺素治疗限制了幼虫器官中发育的淋巴细胞的数量，并在变态期间极大地减少了这些数量低于对照水平。由于这些变化是阶段依赖的，而不是年龄依赖的，低T4处理的甲状旁腺蛙的第二波淋巴生成可能与I类MHC抗原的表达不同步。因此，受损的同种异体排斥反应可能反映了缺乏能够有效识别微小H同种异体抗原和/或自身和同种异体I类抗原的细胞群。
In contrast to the adult pattern of allograft reactivity, larval South African clawed frogs (Xenopus) either become tolerant of adult major histocompatibility complex (MHC) disparate skin grafts or reject them slowly. Larvae fail to reject grafts that are incompatible at minor histocompatibility (H) loci (MHC‐identical); rather, they become immunologically tolerant. We report here that early thyroidectomized (thyroidx) larvae, forced to metamorphose precociously on a regimen of thyroxine (T4) treatment, showed larva‐like responses in that their ability to reject skin allografts that differed by minor H loci or one MHC haplotype was significantly impaired relative to agematched intact postmetamorphic controls. During the normal ontogeny ofXenopus, lymphocyte numbers increase in larval life, decrease during metamorphosis, and increase to adult levels at 6‐12 months of age. Thyroidectomy and a low‐dose regimen of thyroxine treatment limited the number of lymphocytes that developed in larval organs and very dramatically reduced those populations below control levels during metamorphosis. Because these changes were stage‐dependent rather than age‐dependent, the second wave of lymphopoiesis in thyroidx frogs treated with low T4may occur out of synchrony with the expression of Class I MHC antigens. Impaired allograft rejection, therefore, may reflect the absence of a population of cells that can effectively recognize minor H alloantigens and/or self and allo Class I antigens.