Yoshikai Y, Matsuzaki G, Kishihara K, Nomoto K, Yokokura T, Nomoto K
Department of Immunology, Kyushu University, Fukuoka, Japan.
Infect Immun. 1988 Aug;56(8):2069-74. doi: 10.1128/iai.56.8.2069-2074.1988.
To determine whether environmental antigens such as intestinal microflora contribute to expansion of the T-cell repertoire, age-related changes in the expression level of T-cell antigen receptor genes encoding gamma, beta, and alpha chains were compared in the lymphoid tissues of conventional versus germfree mice. Irrespective of the conditions of maintenance, an age-associated increase in the expression of the gamma-chain gene was evident in the thymus and spleen. Both conventional and germfree old mice (age, 40 weeks) had a relatively high proportion of Thy1+ L3T4- Lyt2- cells but a reduced level of Thy1+ L3T4- Lyt2+ cells in the thymus compared with their counterparts (age 8 weeks). The thymic dysfunction but not the stimulation by intestinal microflora may contribute to this age-related increase in gamma-gene transcripts in these tissues. On the other hand, an age-associated increase in the expression of gamma RNA was not evident in the mesenteric lymph nodes of germfree mice, although a remarkable increase in the gamma-chain gene messages was detected in the lymph nodes of the aged conventional mice. These results suggest that the expression of gamma RNA in cells of gut-associated lymphoid tissue is partly influenced by intestinal microflora.
为了确定诸如肠道微生物群等环境抗原是否有助于T细胞受体库的扩增，我们比较了常规饲养小鼠和无菌小鼠淋巴组织中编码γ、β和α链的T细胞抗原受体基因表达水平的年龄相关变化。无论饲养条件如何，γ链基因的表达在胸腺和脾脏中均呈现出与年龄相关的增加。与8周龄的对照小鼠相比，40周龄的常规饲养老年小鼠和无菌老年小鼠胸腺中Thy1+L3T4-Lyt2-细胞比例相对较高，但Thy1+L3T4-Lyt2+细胞水平降低。胸腺功能障碍而非肠道微生物群的刺激可能导致这些组织中γ基因转录本与年龄相关的增加。另一方面，无菌小鼠肠系膜淋巴结中γRNA的表达没有明显的年龄相关增加，尽管在老年常规饲养小鼠的淋巴结中检测到γ链基因信息显著增加。这些结果表明，肠道相关淋巴组织细胞中γRNA的表达部分受肠道微生物群的影响。
