BIOCHEMISTRY OF INSECT HEMOCYTES

许多重要的人类寄生虫病是由昆虫传播的 向量。引起疟疾或丝虫病等疾病的生物体必须 逃避或击败其昆虫媒介的防御反应， 成功传播到人类宿主。 但 昆虫和寄生虫之间的细胞和分子相互作用 生物体还不太了解。与我们详细的 脊椎动物免疫系统的知识， 昆虫的免疫反应在很大程度上仍然是一个谜。 的主要反应 昆虫转化为真核寄生虫的过程是将入侵的生物体包裹起来 寄生昆虫的血细胞。该项目的长期目标是 鉴定和表征来自昆虫血细胞的蛋白质， 参与封装过程。我们将以下列方式处理这个问题： 一组独特的抗曼陀罗血细胞单克隆抗体的应用 我们所创造的六分之一具体目标是： 1)颗粒血细胞囊泡内分子的鉴定， 在浆细胞和颗粒血细胞的表面， 血细胞粘附和包囊。我们将筛选单克隆抗体 抗体，以找到那些可以破坏浆细胞扩散，血细胞 粘附或包封。 2)目标1中鉴定的分子的表征。 我们将使用 单克隆抗体作为试剂破坏血细胞反应， 确定相应抗原的大小，以纯化 相应抗原，并克隆相应抗原的cDNA 从血细胞库中。我们将确定cDNA的序列， 分析推导的血细胞蛋白质的氨基酸序列。 在血细胞包裹中起作用的蛋白质的鉴定是 这是了解它们如何运作的第一步， 了解寄生虫如何避免昆虫的包囊反应 人类疾病的传播媒介。

A number of important human parasitic diseases are transmitted by insect vectors. Organisms that cause diseases such as malaria or filariasis must evade or defeat the defensive responses of their insect vectors if successful transmission to human hosts is to take place. However, the cellular and molecular interactions between insects and such parasitic organisms are not well understood. In comparison with our detailed knowledge of the vertebrate immune system, the molecular mechanisms of insect immune responses remain largely a mystery. The primary response of insects to eukaryotic parasites is encapsulation of the invading organism by the host insect's hemocytes. The long term objective of this project is to identify and characterize proteins from insect hemocytes that are involved in the encapsulation process. We will approach this problem with the use of a unique panel of monoclonal antibodies to hemocytes of Manduca sexta that we have generated. The specific aims are: 1) Identification of molecules within the vesicles of granular hemocytes or on the surface of plasmatocytes and granular hemocytes that are involved in hemocyte adhesion and encapsulation. We will screen our panel of monoclonal antibodies to find those that can disrupt plasmatocyte spreading, hemocyte adhesion, or encapsulation in in vitro assays. 2) Characterization of molecules identified in Aim 1. We will use the monoclonal antibodies that disrupt hemocyte responses as reagents to determine the size of the corresponding antigen, to purify the corresponding antigens, and to clone cDNAs for the corresponding antigens from hemocyte libraries. We will determine the sequences of the cDNAs and analyze the deduced amino acid sequences of the hemocyte proteins. The identification of proteins that function in hemocyte encapsulation is a first step toward understanding how they function and eventually toward understanding how parasites avoid the encapsulation response in insect vectors of human diseases.