鸡嗉囊中淋巴细胞发育的研究

A study on development of lymphocytes in the chicken crop

【目的】研究鸡出壳后不同日龄嗉囊中T淋巴细胞及其亚群和B淋巴细胞的定位分布及数量变化规律等一系列的发育过程．【方法】采用单克隆抗体，通过免疫组织化学方法，观察并统计各取材日龄相应细胞的分布和数量．【结果和结论】1日龄时， CD3＋、CD4＋和CD8＋细胞即已出现， Bu-1 b＋细胞于出壳后4日龄时出现．定位分布上， CD3＋细胞主要分布于黏膜上皮基底层及固有层中，7日龄首次出现以CD3＋细胞为中心的淋巴聚集物；CD4＋细胞主要分布于固有层中；CD8＋细胞最初主要分布在黏膜固有层中，随日龄增长逐渐向上皮方向突入，最终形成含有CD8＋细胞浸润的淋巴上皮；Bu-1b＋细胞主要分布于黏膜固有层中，特别是在小血管周围．于35日龄观察到以Bu-1b＋细胞为中心的生发中心．在数量变化上，CD3＋、CD4＋、CD8＋细胞数量整体呈逐渐增加趋势，部分阳性细胞数量在14和21日龄时稍有下降，35～56日龄时阳性细胞数量缓慢增加，基本达到成熟水平．Bu-1b＋细胞数量随着日龄的增加持续增多，且后期的增长速率大于T细胞的增长速率．结果表明，嗉囊作为鸡消化系统的一部分，具有由淋巴细胞和淋巴聚集物构成的免疫防线，为肠相关淋巴组织中的一个重要组成部分．

[Objective]To study the appearance , distribution and quantity variation of immunocytes-T lymphocytes and its subpopulations and B lymphocytes in different periods , analyzing the developmental process of immunocytes in the chicken crop .[Method]The mono-antibodies and immunohistochemistry was used to observe the distribution and count the number of the relevant cell in every age .[Result and conclusion]The results showed that CD3 ＋, CD4 ＋and CD8 ＋cells appeared in the first day after post-hatching .Bu-1 b＋cells were observed in the 4 rh day .CD3 ＋cells mainly distributed in the epithelium and lamina propria , and the lymphoid aggregates covered by CD 3 ＋cells were first observed in the 7 th day af-ter post-hatching.CD4 ＋cells were located in the lamina propria .At first, CD8 ＋cells mainly distributed in the lamina propria of the mucosa .With the age increasing , CD8 ＋cells slightly migrated and infiltrated to the epithelium of the mucosa , which were transformed to the lymphoepithelium .Bu-1 b＋cells mainly distributed in the lamina propria , especially around the vessels .The germinal center which was covered by the Bu-1a ＋cells was first observed in the 35th day after post-hatching.The amount of CD3 ＋, CD4 ＋, and CD8 ＋cells kept increasing with the age; the amount of parts of positive cells decreased in the 14th and 21th day;it slightly increased after this date and reached mature level around the 56th day.Bu-1b＋cells continuously kept increasing with age , its rising rate was higher than T lymphocytes during the later period.The research showed that as a part of the digest system in the chicken , the crop posses ses the mucosal immunity which consists of the lymphoid aggregates and the lymphocytes .The crop is an impor-tant part of gut-associated lymphoid tissue （ GALT） .