IMMUNE PROPHYLAXIS AGAINST AMEBIASIS

肠道原虫溶组织内阿米巴是致病的主要原因。 以及全球范围内的死亡率。一般来说，感染和感染的传播 由此导致的阿米巴结肠炎和肝脓肿是由于卫生条件差造成的。 在这种情况下，没有疫苗可用。通过定义以下机制 组织的寄生虫和裂解与人体免疫反应，实质 疫苗研发取得了进展。无论是体液还是细胞- 介导的机制对阿米巴肝的保护作用 脓肿。粘膜免疫在相关肠病模型中的作用 阿米巴病还没有定义。一种260 kDa半乳糖抑制的寄生虫 黏附蛋白(GIAP)介导滋养体与结肠的结合 粘蛋白、上皮细胞和宿主炎症细胞。GIAP绑定是 组织裂解杆菌对宿主组织依赖于钙离子的裂解所必需的。 Giap由170 kDa的重亚基和35 kDa的轻亚基组成。 重亚单位具有抗原性和糖类结合活性。 纯化的土生GIAP疫苗在沙土鼠中的高效性 阿米巴白色脓肿模型；来自Giap Heavy亚基的基因 已被克隆和测序。已治愈的侵袭性阿米巴病患者 唾液中的SIGA给了武元甲。这项建议的目标是：1) 明确粘膜抗GIAP分泌型IgA在免疫中的作用 肠道阿米巴病；2)构建重组GIAP亚单位疫苗 对肠道阿米巴病和阿米巴肝的灵长类动物模型有效 脓肿；3)确定是否使用所选的重组组织溶血性肠杆菌 抗原与GIAP亚单位结合将增强疫苗效力。 该提案的具体目的和方法是：1)定义SIGA 人感染和实验对GIAP重亚单位的反应 唾液和肠道阿米巴病的酶联免疫吸附试验检测 肠道分泌物；2)确定Giap的哪些部分重 亚基通过产生黏附诱导保护性SIgA反应- 抑制性IgA单抗可重亚单位， 用SIgA法检测GIAP亚基免疫小鼠的效果 猴免疫球蛋白A单抗的免疫应答和被动免疫 重组GIAP抗体及其主动免疫的研究 确定对实验性肠道的保护作用的亚基 阿米巴病；以及3)在恒河猴和沙鼠模型中确定 一种重组阿米巴对实验性肠道和肝脏阿米巴病的疗效 含GIAP亚单位和主要半胱氨酸的阿米巴病亚单位疫苗 蛋白水解酶或肝脓肿特异性29 kDa表面抗原。上一首 研究和初步数据表明，拟议的研究将 大大提高我们对溶组织埃希氏菌粘膜免疫的认识 并导致开发出一种有效的阿米巴病亚单位疫苗。

The enteric protozoan Entamoeba histolytica is a major cause of morbidity and mortality worldwide. In general, transmission of infection and resultant amebic colitis and liver abscess is due to poor sanitary conditions, there is no vaccine available. By defining the mechanisms of parasite and lysis of tissue and the human immune response, substantial progress is vaccine development has occurred. Both humoral and cell- mediated mechanisms are operative in protection against amebic liver abscess. The role of mucosal immunity in a relevant model of intestinal amebiasis has not been defined. A parasite 260kDa galactose-inhibitable adherence protein (GIAP) mediates binding of trophozoites to colonic mucins, epithelial cells and host inflammatory cells. GIAP binding is required for the CA ++ dependent lysis of host tissues by E. histolytica. The GIAP consists of a 170kDa heavy subunit and a 35kDa light subunit, the heavy subunit is antigenic and possesses carbohydrate binding activity. Purified native GIAP is highly efficacious as a vaccine in the gerbil model of amebic livery abscess; the gene from the GIAP heavy subunit has been cloned and sequenced. Patients cured of invasive amebiasis possess salivary sIgA to the GIAP. The objectives of this proposal are: 1) to define the role of mucosal anti-GIAP secretory IgA (sIgA) in immunity intestinal amebiasis; 2) to construct a recombinant GIAP subunit vaccine effective in primate models of intestinal amebiasis and amebic liver abscess; 3) to determine if use of selected E. histolytica recombinant antigens in combination with GIAP subunits will enhance vaccine efficacy. The specific aims and methods of this proposal are: 1) to define the sIgA response to the GIAP heavy subunit in human infection and experimental intestinal amebiasis in the baboon by ELISA assay of salivary and intestinal secretions; 2) to identify which portions of the GIAP heavy subunit elicit protective sIgA responses by production of adherence- inhibitory IgA monoclonal antibodies to may the heavy subunit, immunization of mice with selected GIAP subunits with assay of sIgA responses, and passive immunization of baboons with IgA monoclonal antibodies and active immunization of baboons with recombinant GIAP subunits to determine protection against experimental intestinal amebiasis; and 3) to determine in the baboon and gerbil models of experimental intestinal and liver amebiasis the efficacy of a recombinant amebiasis subunit vaccine containing GIAP subunits and the major cysteine proteinase or the liver abscess specific 29kDa surface antigen. Previous studies and preliminary data indicate that the proposed studies will greatly enhance our understanding of mucosal immunity to E. histolytica and lead to development of an effective amebiasis subunit vaccine.