Imaoka A, Matsumoto S, Setoyama H, Okada Y, Umesaki Y
Yakult Central Institute for Microbiological Research, Tokyo, Japan.
Eur J Immunol. 1996 Apr;26(4):945-8. doi: 10.1002/eji.1830260434.
Intraepithelial lymphocytes (IEL), particularly alpha beta TCR-bearing IEL (alpha beta-IEL), dramatically increase in number after microbial colonization of formerly germ-free (ex-GF) mice (Umesaki et al., Immunology 1993. 79: 32). In this study, the kinetics of expansion of IEL after microbial colonization in ex-GF mice were investigated by the bromodeoxyuridine (BrdUrd) continuous labeling method. In GF mice, gamma delta- and alpha beta-IEL were gradually labeled with BrdUrd, reaching approximately 30% and 15% labeling, respectively, after 10 days of continuous BrdUrd labeling. In conventional (CV) mice, the percentage of BrdUrd-labeled alpha beta-IEL was a little higher than that for gamma delta-IEL. The maximal labeling for alpha beta-IEL and gamma delta-IEL reached 50-60% and 40%, respectively, in 10 days. In the case of conventionalized ex-GF mice, continuous labeling was started 11 days after microbial colonization of GF mice because alpha beta-IEL outnumbered gamma delta-IEL during this period. In this case, 75% of alpha beta-IEL and 67% of gamma delta-IEL were labeled with BrdUrd in 10 days. On the other hand, the apparent half lives of alpha beta-IEL and gamma delta-IEL were 10 and 20 days, respectively in CV mice. These results strongly suggest that the number of IEL, particularly alpha beta-IEL, increases after microbial colonization through recruitment into the cell cycle of a large proportion of IEL or their immediate precursors. The difference in the relative BrdUrd-labeling rate of alpha beta-IEL to that of gamma delta-IEL between germ-free and conventionalized mice indicates a preferential increase in the alpha beta-IEL subset during the course of conventionalization.
上皮内淋巴细胞（IEL），尤其是携带αβTCR的IEL（αβ-IEL），在先前无菌（ex-GF）小鼠被微生物定殖后数量急剧增加（Umesaki等人，《免疫学》1993年。79: 32）。在本研究中，通过溴脱氧尿苷（BrdUrd）连续标记法研究了ex-GF小鼠微生物定殖后IEL的扩增动力学。在GF小鼠中，γδ-IEL和αβ-IEL逐渐被BrdUrd标记，连续BrdUrd标记10天后，分别达到约30%和15%的标记率。在常规（CV）小鼠中，BrdUrd标记的αβ-IEL的百分比略高于γδ-IEL。αβ-IEL和γδ-IEL的最大标记率在10天内分别达到50 - 60%和40%。对于常规化的ex-GF小鼠，由于在此期间αβ-IEL数量超过γδ-IEL，所以在GF小鼠微生物定殖11天后开始连续标记。在这种情况下，75%的αβ-IEL和67%的γδ-IEL在10天内被BrdUrd标记。另一方面，在CV小鼠中，αβ-IEL和γδ-IEL的表观半衰期分别为10天和20天。这些结果有力地表明，微生物定殖后IEL数量增加，尤其是αβ-IEL，是通过大量IEL或其直接前体进入细胞周期实现的。无菌小鼠和常规化小鼠之间αβ-IEL与γδ-IEL相对BrdUrd标记率的差异表明，在常规化过程中αβ-IEL亚群优先增加。
