不同日龄鸡鼻腔黏膜相关淋巴组织中T淋巴细胞亚群分布的变化规律

Localization changes of T lymphocyte subpopulations in chicken nasal-associate lymphoid tissues at different ages

为了解鸡鼻腔黏膜相关淋巴组织(NALT)不同时期的免疫状态,选择不同日龄的海兰白鸡的鼻组织,利用免疫组织化学方法研究CD4+、CD8+T淋巴细胞亚群的出现、定位分布及数量变化过程。结果显示,CD8+T淋巴细胞最初于胚胎20日出现,而CD4+T淋巴细胞于出壳后1日龄出现。在定位分布上,NALT以鼻泪管开口处的最为发达,随着4日龄时鼻泪管周围NALT的出现,CD4+T淋巴细胞便成为NALT中主要的T淋巴细胞亚群,并且在14日龄以后,T淋巴细胞亚群的分布更具区域化,即CD4+T淋巴细胞聚集在鼻黏膜上皮下固有层底端,占据NALT的中下部区域,而CD8+T淋巴细胞则分散在NALT的中部。在数量变化上,T淋巴细胞亚群整体呈逐渐增加趋势,其中4日龄之前CD8+细胞的数量多于CD4+细胞,而此后各日龄CD4+细胞的数量都显著多于CD8+细胞。结果表明,鸡NALT中T淋巴细胞亚群的分布和数量都呈现日龄相关性变化,并且在14日龄达到较为成熟的水平。

The aim of this study was to investigate the immune states in different ages of chicken nasal associate lymphoid tissues. Using nasal tissues of Hailanbai chicken at different ages, the location,distribution changes and quantity of CD4＋ and CD8＋ T lymphocyte subpopulations in nasal-associate lymphoid tissue（NALT） were studied using immunohistochemistry staining. In result, CD8＋ lymphocytes appeared firstly on embryonic day 20,while CD4＋ cells appeared at 1-day-old. NALT around nasolacrimal duct open- ings was well developed with the appearance of NALT around nasolacrimal duct at 7-day-old,and CD4＋ T lymphocytes were the main T lymphocyte subsets in NALT at 7-day-old, the distribution of T lymphocyte subsets was more regionalization and CD4＋ T lymphocytes were enriched at the bottom of the lamina propria of the nasal mucosa and occupied in the lower region of NALT,while CD8＋ T lymphocytes scattered in the middle of NALT. The amount of T lymphocytes subpopulations increased gradually,and the number of CDS＊ cells was higher than that of CD4＋ cells before 4-day-old. Afterwards the number of CD4＋ cells was significantly higher than that of CD8＋ cells at each age. In conclusion, the distribution and amount of T lymphocyte subsets in chicken NALT are age-related,and reach a constant level at 14-day-old.