Iarilin A A, Kharchenko T Iu
Radiats Biol Radioecol. 1993 Jul-Aug;33(4):542-8.
The lobes of thymus of newborn mice irradiated on 17 day of embryonic life or on 1 day after the birth were transplanted under the renal capsule of adult mice. The recipients were thymectomized, lethally irradiated and reconstituted by syngeneic bone marrow cells treated by monoclonal anti-Thy-1-antibody and complement 1 month before the transplantation of thymus. Colonization of the thymus transplants, number and functional activity of T cells in peripheral lymphoid organs of recipients were measured 30 day after the transplantation of thymus. The colonization of the thymus transplants was decreased after irradiation of the thymus donors in doses of 6 and 8 Gy. The number of L3T4+ cells (T helpers) in the lymph nodes of the recipients and the level of the humoral immune response on thymus-dependent antigen were decreased after the exposure of the thymus donors to dose of 1 Gy or higher and the level of graft-versus-host reactivity of lymph node cells--after the dose of 2 Gy and higher. The degree of the suppression of the humoral immune response was higher when the donors of thymus were irradiated in embryonal period of development than after the birth. Thus the damage of the components of thymic microenvironment responsible for the T cell development can be arisen by relatively low doses of ionizing irradiation.
将胚胎期第17天或出生后第1天接受照射的新生小鼠的胸腺叶移植到成年小鼠的肾包膜下。受体在胸腺移植前1个月进行胸腺切除、致死性照射，并用单克隆抗Thy-1抗体和补体处理的同基因骨髓细胞进行重建。在胸腺移植30天后，测量胸腺移植的定植情况、受体外周淋巴器官中T细胞的数量和功能活性。胸腺供体接受6 Gy和8 Gy剂量照射后，胸腺移植的定植减少。胸腺供体接受1 Gy或更高剂量照射后，受体淋巴结中L3T4+细胞（T辅助细胞）的数量以及对胸腺依赖性抗原的体液免疫反应水平降低；接受2 Gy或更高剂量照射后，淋巴结细胞的移植物抗宿主反应性水平降低。与出生后相比，胸腺供体在胚胎发育时期接受照射时，体液免疫反应的抑制程度更高。因此，相对低剂量的电离辐射可导致负责T细胞发育的胸腺微环境成分受损。
