中文摘要：

为研究不同日龄雏鸡免疫后诱导消化道的共同黏膜免疫反应，本实验采用新城疫病毒（NDV） LaSota疫苗株经滴鼻点眼途径免疫雏鸡，分别于免疫后不同时间采集消化道洗脱液和胆汁样品，采用间接ELISA对其IgM、IgG和SIgA抗体水平进行检测。结果显示：NDV特异性IgM于免疫后4 d即可检出，并于第7 d达到峰值后迅速下降；而IgA于免疫后第7 d可检测到，并于第21 d达到较高水平。13日龄免疫组总抗体水平高于6日龄之前免疫组，但1日龄和3日龄免疫组不能够诱导消化道黏膜产生抗体。胃肠道不同部位免疫反应强度不同。其中前胃和十二指肠两个部位的免疫反应较强，而回肠和盲肠的免疫反应较弱。此外，胆汁中以较高SIgA抗体水平为主。研究表明，NDV弱毒苗滴鼻点眼后能够诱导消化道产生共同黏膜免疫反应，并且与日龄存在相关性。该研究结果为雏鸡共同黏膜免疫机制的研究和有效防制新城疫提供了实验依据。

英文摘要：

To investigate the common mucosal immune responses in gastrointestinal tract of chicks vaccinated with Newcastle disease virus （NDV） vaccine via ocular-nasal route, the SIgA, IgG and IgM were detected by indirect ELISA in gastrointestinal washings and bile at different days post immunization （DPI）, respectively. The results showed that NDV IgM was initially detected at 4 DPI, and decreased rapidly after reaching the peak level at 7 DPI. SIgA was detected at 7 DPI and reached the higher level at 21 DPI. The total antibody levels in 13-day-old chicks vaccinated with attenuated NDV vaccine were higher than that in 6-day-old vaccinated chicks. However, different parts of gastrointestinal tract had varying immune response intensity. The stronger immune responses were detected in first stomach and duodenum, while the weak immune responses were induced in ileum and cecum. In addition, the highest levels of SIgA were in bile. Therefore, the results revealed that gastrointestinal mucosal immune response degree varied with the increase of age. These results could provide experimental basis to study the early mechanism of common mucosal immune responses and to effective control of ND.