MUCOSAL IMMUNITY TO CHLAMYDIAL INFECTION

这个项目的目标是直接确定衣原体是否 特异性分泌型IgA（sIgA）在保护免受或 解决小鼠生殖道衣原体感染。为了 为了解决这个问题，我们将1）产生分泌 衣原体特异性多聚IgA（pIgA）单克隆抗体（mAb） 表面成分，以及2）确定其防护能力， 衣原体生殖道感染的小鼠模型。 mAb将 通过皮下植入分泌单克隆抗体的 同源小鼠背部的杂交瘤（背包肿瘤系统）。这 这种方法之所以成为可能，是因为全身递送的pIgA是 与分泌片段特异性复合并转运至粘膜 表面的IgA和IgA，而单体IgA（mIgA）和IgG不是。到目前为止， 已经产生了三种鼠杂交瘤，其产生特异于 沙眼衣原体MoPn的表面。 这些杂交瘤产生于 使用肠系膜淋巴结衍生的淋巴细胞的融合实验 富集IgA表面阳性细胞的群体。 使用pIgA 和分泌IgG的杂交瘤，我们目前正在进行一项试验， 在我们的实验室中进行了一个实验来表征背包肿瘤系统。 初步数据表明，肿瘤发展的发病率是 > 80%，这种肿瘤产生高水平的mAb，并且这种肿瘤 生长速率在肿瘤细胞系之间显著不同。与此 根据这些信息，我们现在可以评估抗衣原体sIgA在 保护生殖道粘膜免受衣原体定植， 以及它在解决生殖道感染中的作用。 相同的mAb集合将允许未来的研究， 体外中和衣原体感染性的体内保护，如 以及粘膜特异性IgA抗体依赖性 细胞毒性作为保护性免疫的潜在机制。

The goal of this project is to directly determine whether Chlamydia specific secretory IgA (sIgA) plays a role in protection from, or resolution of, chlamydial infection of the mouse genital tract. In order to address this question we will 1) produce murine hybridomas that secrete polymeric IgA (pIgA) monoclonal antibodies (mAbs) specific to chlamydial surface components, and 2) determine their ability to protect against chlamydial genital tract infection in a murine model. mAbs will be administered to naive animals by subcutaneously implanting a mAb secreting hybridoma in the backs of syngeneic mice (backpack tumor system). This approach is made possible by the fact that systemically delivered pIgA is specifically complexed with secretory piece and transported to mucosal surfaces as sIgA, whereas monomeric IgA (mIgA) and IgG are not. To date, three murine hybridomas have been generated that produce pIgA specific for the surface of Chlamydia trachomatis MoPn. These hybridomas resulted from fusion experiments using mesenteric lymph node derived lymphocyte populations that were enriched for IgA surface positive cells. Using pIgA and IgG secreting hybridomas, we are currently conducting a pilot experiment to characterize the backpack tumor system in our laboratory. Preliminary data indicate that the take rate for tumor development is >80%, that high levels of mAb are produced by such tumors, and that tumor growth rates vary significantly between tumor cell lines. With this information, we can now evaluate the role of anti-chlamydial sIgA in protection against chlamydial colonization of the genital tract mucosae as well as its role in resolving established infections of the genital tract. The same collection of mAbs will allow for future studies that compare in vivo protection with in vitro neutralization of chlamydial infectivity, as well as, investigations of mucosae specific IgA antibody dependent cellular cytotoxicity as a potential mechanism of protective immunity.