MUCOSAL IMMUNE RESPONSES OF A RECOMBINANT CHLAMYDIA TRACHOMATIS MOMP PROTEIN

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 沙眼衣原体是世界上细菌性传播疾病的主要原因。我们利用重组沙眼衣原体肺炎MOMP(主要外表面蛋白)亚单位蛋白开发了一种黏膜疫苗原型。在这个原型中，MOMP分子与修饰的霍乱毒素(CTB)基因融合，作为粘膜佐剂(rMOMP-CTB)。我们已经报道，用这种疫苗鼻腔免疫的小鼠会产生强烈的粘膜和全身免疫反应。此外，rMOMP-CTB黏膜免疫可保护小鼠免受沙眼衣原体的攻击感染。接下来，我们研究了细胞因子在保护小鼠免受这种挑战感染中可能发挥的作用。用rMOMP对免疫小鼠脾细胞进行体外再刺激，48h后收集上清液。培养上清液中Th1(IL-2、IL-12p40和干扰素-γ)和Th2(IL-4、IL-5和IL-10)细胞因子用细胞因子酶联免疫吸附试验检测，rMOMP免疫小鼠后可产生Th1(干扰素-γ和IL-12p40)和Th2(IL-5)类细胞因子。干扰素-γ和IL-12p40细胞因子的水平与沙眼衣原体免疫小鼠的细胞诱生水平相当。然而，沙眼衣原体小鼠的细胞比rMOMP免疫的小鼠产生更多的IL-10。有趣的是，只有来自rMOMP小鼠的细胞才能诱导高水平的IL-5。这一发现具有重要意义，并与沙眼衣原体攻击感染前后这些小鼠全身和粘膜中高水平的IgA产生有关。众所周知，小鼠IL-5可以通过刺激B细胞刺激IgA的产生。此外，这种细胞因子对B细胞同型转换、生长和分化为分泌IgA的浆细胞至关重要。这些发现有力地表明，rMOMP在rMOMP免疫的小鼠中比沙眼衣原体免疫的小鼠诱导了与保护性免疫相关的强大的Th1/Th2细胞因子反应。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Chlamydia trachomatis is the leading cause of bacterial sexually transmitted diseases in the world. We have developed a prototype mucosal vaccine utilizing the recombinant C. trachomatis mouse pneumonitis MOMP (major outer surface protein) subunit protein. In this prototype the MOMP molecule is genetically fused with modified cholera toxin (CTB) as a mucosal adjuvant (rMOMP-CTB). We have reported that mice immunized intranasally with this vaccine develop strong mucosal and systemic immune responses. In addition, mucosal immunization with rMOMP-CTB protected mice from a challenge infection with live C. trachomatis. We next investigated the role that cytokines may play in protecting mice from this challenge infection. Spleen cells obtained from immunized mice were restimulated in vitro with rMOMP, and supernatants were collected after 48 hr post-stimulation. Th1 (IL-2, IL-12p40 and IFN-y) and Th2 (IL-4, IL-5 and IL-10) cytokines in supernatants were analyzed using cytokine ELISA's. Mice immunized with rMOMP elicited Th1 (IFN-y and IL-12p40) and Th2 (IL-5) type responses. The levels of both IFN-y and IL-12p40 cytokines were comparable to those that were induced by cells from C. trachomatis immunized mice. However, cells from the C. trachomatis mice produced more IL-10 than those from rMOMP immunized mice. Interestingly only cells from rMOMP mice induced high levels of IL-5. This finding is of significance, and correlates with the high systemic and mucosal production of IgA in these mice before and after a challenge infection with live C trachomatis. Murine IL-5 is known to stimulate the production of IgA by stimulated B cells. Moreover, this cytokine is crucial for B-cell isotype switch, growth and differentiation into IgA-secreting plasma cells. These findings strongly suggest that rMOMP elicited strong Th1/Th2 cytokine responses that correlated with protective immunity in rMOMP immunized mice than in the C. trachomatis mice.