Structure & Function of E.histolytica Adherence Lectin

描述(申请人提供)：阿米巴虫通过 肠道上皮引发阿米巴结肠炎，这是世卫组织估计的一种疾病 每年杀死10万人。我们推测溶组织内阿米巴 侵袭需要肠壁上皮细胞中毒。 260 kDa凝集素转移到上皮细胞膜。我们建议 这是一个由三个步骤组成的过程：(A)初步遵守 通过GPI连接的150 kDa寄生虫凝集素的上皮细胞GainAc；(B) 二次募集到完整膜的寄主-寄生虫界面 260 kDa Ga1NAc凝集素；和(C)插入基底外侧上皮细胞 胞质为260 kDa的凝集素胞浆尾部。沉醉于生活中的 假设上皮细胞是由细胞表面的整合素基序产生的。 凝集素胞质尾巴干扰上皮细胞结合 细胞外基质的整合素。我们将通过4个具体的例子来测试这一点 目标。具体目标1将完成结构和功能 溶组乳杆菌新发现的150 kDa凝集素的特性 特定目标2将研究150 kDa和260 kDa凝集素的相互作用 在阿米巴与上皮细胞的相互作用过程中。《特定目标3》将进行测试 寄生虫向猪肾上皮细胞转移的机制及后果 260 kDa凝集素。特定目标4将干预依附/入侵过程 通过使用RNA取消150和/或260 kDa凝集素的功能 干扰。这些研究的成功完成将揭开 阿米巴入侵和杀害人类，并承诺提供有效和 阿米巴病防治的合理途径。

DESCRIPTION (provided by the applicant): Invasion of amoebae through the intestinal epithelium initiates amebic colitis, a disease estimated by the WHO to kill 100,000 people annualiy. We hypothesize that Entamoeba histolytica invasion requires intoxication of the epithelial cells lining the intestine by transfer of the 260 kDa lectin into the epithelial cell membrane. We propose that this is a 3 step process consisting of: (A) initial adherence to epithelial cell GaINAc via the GPI-linked 150 kDa parasite lectin; (B) secondary recruitment to the host-parasite interface of the integral membrane 260 kDa Ga1NAc lectin; and (C) insertion into the baso-lateral epithelial cell cytoplasm of the 260 kDa lectin cytoplasmic tail. Intoxication of the epithelial cells is hypothesized to result from the integrin motifs on the lectin cytoplasmic tail interfering with the binding of epithelial cell integrins to the extracellular matrix. We will test this through 4 specific aims. Specific Aim 1 will complete the structural and functional characterization of the newly described 150 kDa lectin of E. histolytica. Specific Aim 2 will study the interaction of the 150 kDa and 260 kDa lectins during amebic interaction with the epithelial cells. Specific Aim 3 will test the mechanism and consequences of parasite transfer to epithelial cells of the 260 kDa lectin. Specific Aim 4 will intervene in the adherence/invasion process by abrogating the functions of the 150 and/or 260 kDa lectins using RNA interference. SUCCESSFUL COMPLETION of these studies will unravel the enigma of amebic invasion and killing of humans, and promises to provide effective and rational approaches to the prevention and treatment of amebiasis.