SURFACE CARBOHYDRATES OF PNEUMOCYSTIS CARINII

卡氏肺孢子虫肺炎是艾滋病的主要死因 患者 在卡氏肺孢子虫发育过程中， 新的脱囊滋养体逐渐开始获得一个电子致密的 外套 完全发育后，囊肿带有一个突出的电子透明 间隔和一个重涂层，富含碳水化合物的外膜， 抗原活性。 几种糖蛋白，包括116 kDa和 沿着α-葡聚糖和β-葡聚糖的45-50 Kda物质占了 囊壁碳水化合物含量（8%）。 卡氏肺孢子虫的结构 碳水化合物在发育过程中的外膜衣，和 成熟后，尚未阐明。 什么是结构 糖蛋白的寡糖链 有哪些 葡聚糖的结构，以及它们如何与壁结合 糖蛋白？ 滋养体是否表现出独特的 成熟的包囊，这种变异是否与糖基化的差异有关 模式？ 人肺中是否存在卡氏肺杆菌特异性抗原 对比老鼠肺 表面糖蛋白是否直接与 CD 4 +T细胞，如果是这样，碳水化合物在其中发挥重要作用吗？ 互动？ 葡聚糖除了结构作用外还有其他作用吗？ 的 拟议的研究将解决这些问题：1。确定 获得的gp 116和gp 45 -50的寡糖链的结构 来自大鼠和人类卡氏肺孢子虫滋养体和包囊。2.完全 表征葡聚糖和其他多糖的结构 卡氏肺孢子虫的细胞壁中发现的 3.比较抗原模式， 分离的成熟孢囊的碳水化合物的结构差异， 滋养体糖蛋白，以及大鼠与人肺卡氏肺孢子虫。4. 检查卡氏肺孢子虫表面糖蛋白和/或碳水化合物 与CD 4 +T细胞结合。 拟议研究的总体目标是分析 卡氏疟原虫包囊和滋养体表面的碳水化合物结构 通过比较两种发育的糖基化模式， 阶段，并确定这些碳水化合物是否参与 介导宿主细胞反应。 获得的数据将进一步促进我们的 了解卡氏肺孢子虫表面分子与 宿主细胞和有价值的策划新的治疗策略， P.艾滋病患者卡氏肺炎

Pneumocystis carinii pneumonia is the leading cause of death in AIDS patients. During P. carinii development, the outer membrane of the newly excysted trophozoite gradually begins to acquire an electron-dense outer coat. Fully developed, the cyst bears a prominent electron-lucent space and a heavily coated, carbohydrate-rich outer membrane exhibiting antigenic activities. Several glycoproteins, including a 116 kDa and a 45-50 Kda species, along with alpha- and beta-glucans, account for the cyst wall carbohydrate content (8%). The structure of P. carinii carbohydrates during the development of the outer membrane coat, and after maturation, has not been elucidated. What are the structures of the oligosaccharide chains of the glycoproteins? What are the structures of the glucans, and how are they associated with the wall glycoproteins? Do trophozoites exhibit a unique antigenic pattern from mature cysts, and is this variation do to differences in glycosylation patterns? Are there antigens specific for P. carinii in human lungs versus rat lungs? Do the surface glycoproteins directly interact with CD4+T cells, and if so, do carbohydrates play a significant role in this interaction? Is there more than a structural role to the glucans? The proposed study will address these questions by: 1. Determining the structures of the oligosaccharide chains of gp116 and gp45-50, obtained from rat and human P. carinii trophozoites and cysts. 2. Completely characterizing the structure of the glucans and other polysaccharides found in the wall of P. carinii. 3. Comparing antigenic patterns and structural differences in carbohydrates of isolated mature cyst and trophozoite glycoproteins, and of rat versus human lung P. carinii. 4. Examining whether P. carinii surface glycoproteins and/or carbohydrates bind to CD4+T cells. The overall objective of the proposed studies is to analyze the carbohydrate structures of P. carinii cyst and trophozoite surface antigens by comparing glycosylation patterns of both developmental stages, and to determine if these carbohydrates are involved in mediating host cellular responses. The data obtained will further our understanding of the interactions of P. carinii surface molecules with host cells and be valuable in scheming new therapeutic tactics to combat P. carinii pneumonia in AIDS patients.