气道嗜酸细胞呈递抗原的研究

A study on antigen presentation of eosinophils in vivo and in vitro

目的 探讨嗜酸细胞 (EOS)在体内和体外呈递抗原的过程和特征。方法 以鸡卵清蛋白 (OVA)致敏和雾化吸入刺激BALB/c小鼠以诱发EOS在气道聚集后将其分离纯化。将曾在气道接触抗原的EOS和致敏T细胞在体外共同培养 ;同时 ,将EOS注入致敏小鼠气道 ,然后在预定的时间收集气管旁淋巴结细胞进行培养。观察由于EOS呈递抗原所引发T细胞在体外和体内的增殖反应的变化。结果 在体外实验中 ,如果没有EOS存在 ,T细胞不增殖。EOS数量逐渐增加之后 ,T细胞随即出现明显的增殖反应并呈数量相关性。在体内实验中 ,致敏小鼠气管内注入EOS 1天后气管旁淋巴结的T细胞增殖反应即有所增强 ,3天后达到峰值 ,1周以后下降。体内T细胞增殖反应随着注入气管的EOS数量的增加而增强。此外 ,无论是体内还是体外实验 ,暴露于某一抗原的EOS仅能将抗原呈递给经同一抗原致敏的T细胞。结论 EOS无论在体内还是在体外均能摄取和处理抗原 ,然后将抗原信息呈递给致敏T细胞促使后者增殖。并且 。

Objective To elucidate the process and characteristics of antigen presentation of eosinophils in vitro and in vivo .Methods BALB/c mice were sensitized and challenged by ovalbumin to recruit the aggregated eosinophil in the airways. The isolated airway eosinophils were co cultured with sensitized T lymphocytes. Meanwhile, purified eosinophils were instilled into the trachea of sensitized mice, and then T cells from the draining lymph nodes were collected. The proliferation responses of T cells both in vitro and in vivo were observed.Results In the absence of eosinophils in in vitro experiments, T cells did not proliferate even when incubated with exogenous antigen. The addition of ovalbumin sensitized eosinophils ( in vivo ) yielded significant eosinophil dose dependent increases in T cell proliferation. In sensitized mice that received airway instillation of antigen exposed eosinophils, T cell proliferation in the paratracheal lymph nodes developed within 1 day, reaching peak at day 3, and declined over 1 week. The in vivo T cell proliferative responses increased with increasing numbers of eosinophils instilled into the tracheas. In both in vitro and in vivo experiments, antigen exposed could only present antigen to T cells sensitized with the same antigen. Conclusions Eosinophils can uptake and process antigen both in vitro and in vivo , and then present processed antigen to sensitized T cells and thus induce T cell proliferation. Moreover, eosinophil induced T cell proliferation is antigen specific.