Adnesion Receptors of the Insect Immune System

描述(由申请人提供)：在遇到他们认为 识别为异物，是昆虫细胞(血细胞)的主要反应 免疫系统是它们聚集在表面的多个层上 一个称为封装的过程中的外来对象。作为启动的 聚集和封装发生时，血细胞将与平时不同 非粘连状态变为粘连状态，并开始表达新的粘连 协调封装过程的蛋白质。许多病原体和 然而，寄生虫能够通过以下方式绕过昆虫的这种宿主防御 阻止或抑制黏附受体的表达。 尽管已知多种黏附受体参与了 哺乳动物免疫系统中细胞的相互作用，没有类似的受体 参与调节包裹体的是昆虫已知的。建立 黏附受体在昆虫免疫反应中的作用，这项研究将 使用研究充分的大型蛾Manduca sexta，通过几条路线继续前进。 与浆细胞黏附和包膜有关的三组蛋白质 将会被调查。(1)颗粒细胞特异性蛋白的功能 将检测浆细胞黏附中的Lacunin。这种多结构域蛋白 存在于异物表面和界面处的胶囊中 贴壁的浆细胞。实验将测试凝血酶反应蛋白的作用 胞浆细胞黏附中的Lacunin结构域。(2)昆虫细胞的功能 血细胞包膜中免疫球蛋白超家族的黏附蛋白 将会被调查。代表推定粘连的重组蛋白 三种表面蛋白的结构域也具有亚胺类球蛋白结构域 因为针对这些表面蛋白产生的抗体将被检测其 对血细胞聚集和包埋的影响。(3)两个浆细胞 在包囊中起作用的完整膜蛋白将是 特色化的。针对这些表面蛋白的单抗破坏了 浆细胞聚集。和封装性。这些单抗是 用于亲和纯化蛋白质进行部分测序。带着信息 现在可以从每个蛋白质的几个肽的部分序列中获得， 将产生探针，用于筛选血细胞cDNA文库并获得 它们的完整序列，这应该揭示出这些 黏附受体。 了解昆虫免疫反应的分子基础将 清楚地有助于了解昆虫血液中病原体的命运 人类疾病的传播者。

DESCRIPTION (provided by the applicant): Upon encountering objects that they recognize as foreign, a primary response of the cells (hemocytes) of the insect immune system is their aggregation in multiple layers on the surfaces of the foreign object in a process known as encapsulation. As the initiation of aggregation and encapsulation occurs, hemocytes switch from their usual nonadherent state to an adherent state and begin expressing new adhesion proteins that orchestrate the encapsulation process. Many pathogens and parasites, however, are able to circumvent this host defense of insects by either preventing or suppressing the expression of adhesion receptors. Although a great variety of adhesion receptors are known to be involved in the interactions of cells in the mammnalian immune system, no comparable receptors involved in regulating encapsulation are yet known for insects. To establish the role of adhesion receptors in the insect immune response, this study will proceed by several routes using the large, well-studied moth Manduca sexta. Three groups of proteins implicated in plasmatocyte adhesion and encapsulation will be investigated. (1) The function of the granular cell-specific protein lacunin in adhesion of plasmatocytes will be tested. This multidomain protein is present in capsules at the interface between the foreign surface and the adherent plasmatocytes. Experiments will test the role of the thrombospondin domains of lacunin in plasmatocyte adhesion. (2) The function of insect cell adhesion proteins from the immunoglobulin superfamily in hemocyte encapsulation will be investigated. Recombinant proteins representing the putative adhesive domains of three surface proteins having iminunoglobulin-like domains as well as antibodies generated to these surface proteins will be assayed for their effects on aggregation and encapsulation of hemocytes. (3) Two plasmatocyte integral membrane proteins, which function in encapsulation, will be characterized. Monoclonal antibodies against these surface proteins disrupt plasmatocyte aggregation. and encapsulation. These monoclonal antibodies were used to affinity purify the proteins for partial sequencing. With information now available on the partial sequences of several peptides from each protein, probes will be generated for screening of a hemocyte cDNA library and obtaining their complete sequences, which should reveal additional features of these adhesion receptors. Understanding the molecular underpinnings of the insect immune response will clearly help in understanding the fate of pathogens in the blood of insect vectors of human diseases.