N.K. Koltsov Institute of Developmental Biology of Russian Academy of Sciences, Moscow, Russia.
Cell Immunol. 2010;266(1):83-9. doi: 10.1016/j.cellimm.2010.09.001. Epub 2010 Sep 15.
Immune proteasomes in thymus are involved in processing of self-antigens, which are presented by MHC class I molecules for rejection of autoreactive thymocytes in adults and probably in perinatal rats. The distribution of immune proteasome subunits LMP7 and LMP2 in thymic cells have been investigated during rat perinatal ontogenesis. Double immunofluorescent labeling revealed LMP7 and LMP2 in thymic epithelial and dendritic cells, as well as in CD68 positive cells - macrophages, monocytes - at all developmental stages. LMP2 and LMP7 were also detected by flow cytometry in almost all thymic CD90 lymphocytes through pre- and postnatal ontogenesis. Our results demonstrate that the immune proteasomes are expressed in all types of thymic antigen presenting cells during perinatal ontogenesis, suggesting the establishment of the negative selection in the thymus at the end of fetal life. The observation of the immune proteasome expression in T lymphocytes suggests their role in thymocyte differentiation besides antigen processing in thymus.
胸腺中的免疫蛋白酶体参与自身抗原的加工，这些自身抗原由 MHC I 类分子呈递，以在成人和可能在围生期大鼠中排斥自身反应性胸腺细胞。在大鼠围生期发生过程中，研究了免疫蛋白酶体亚基 LMP7 和 LMP2 在胸腺细胞中的分布。双免疫荧光标记显示 LMP7 和 LMP2 存在于胸腺上皮细胞和树突状细胞中，以及 CD68 阳性细胞——巨噬细胞、单核细胞——在所有发育阶段。通过产前和产后发生，流式细胞术也在几乎所有胸腺 CD90 淋巴细胞中检测到 LMP2 和 LMP7。我们的结果表明，在围生期发生过程中，免疫蛋白酶体在所有类型的胸腺抗原呈递细胞中表达，这表明在胎儿生命末期在胸腺中建立了阴性选择。免疫蛋白酶体在 T 淋巴细胞中的表达表明，它们除了在胸腺中进行抗原加工外，还在胸腺细胞分化中发挥作用。
