Takeuchi M, Miyazaki H, Mirokawa K, Yokokura T, Yoshikai Y
Laboratory of Germfree Life, Nagoya University School of Medicine, Japan.
Eur J Immunol. 1993 Jun;23(6):1409-11. doi: 10.1002/eji.1830230637.
Age-related changes in T cell subsets were examined in intestinal intraepithelial lymphocytes (i-IEL), which contain unique T cells differentiating extrathymically. In 2-month-old mice bred under conventional condition, i-IEL consisted of a large number of CD4-CD8 alpha/alpha+ cells bearing either T cell receptor (TcR)alpha/beta or TcR gamma/delta and only a few CD4+CD8 alpha- cells. In aged mice (6 months old and 24 months old), unique CD4+CD8 alpha/alpha+ i-IEL bearing TcR alpha/beta increased in number and conversely the proportion of TcR gamma/delta+ i-IEL was decreased. Such an increase in number of CD4+CD8 alpha/alpha+ cells was detected in i-IEL from aged (14-months old) nude mice, but not in aged (14 months old) germ-free mice, suggesting that a significant fraction of TcR alpha/beta T cells such as CD4+CD8 alpha+ i-IEL can develop along an extrathymic pathway under the influence of intestinal microflora with age.
在肠道上皮内淋巴细胞（i-IEL）中检测了与年龄相关的T细胞亚群变化，i-IEL包含在胸腺外分化的独特T细胞。在常规条件下饲养的2个月大的小鼠中，i-IEL由大量携带T细胞受体（TcR）α/β或TcRγ/δ的CD4-CD8α/α+细胞以及少量CD4+CD8α-细胞组成。在老年小鼠（6个月大和24个月大）中，携带TcRα/β的独特CD4+CD8α/α+i-IEL数量增加，相反，TcRγ/δ+i-IEL的比例下降。在14个月大的老年裸鼠的i-IEL中检测到CD4+CD8α/α+细胞数量增加，但在14个月大的老年无菌小鼠中未检测到，这表明随着年龄的增长，在肠道微生物群的影响下，相当一部分TcRα/βT细胞（如CD4+CD8α+i-IEL）可以沿着胸腺外途径发育。
