IMMUNOLOGY OF BABESIOSIS

血液寄生虫病是世界上一半牲畜的地方病 生产领域，是最重要的障碍，以改善 发展中国家的肉类和牛奶生产。估计超过 仅巴贝斯虫病就有5亿头牛的风险，尽管几十年来 研究，仍然没有有效，实用和安全的方法， 使牲畜免疫这种疾病。牛巴伯氏菌的病理学 牛的感染与恶性疟原虫引起的感染非常相似 感染，并以全身性循环系统 寄生红细胞在毛细血管中的紊乱和隔离 床，尤其是大脑。开发一个成功的 巴贝斯虫疫苗是基于观察，从急性 感染与保护性免疫的发展有关， 用粗寄生虫提取物免疫可诱导部分保护 随后的挑战。然而，人们对它知之甚少。 保护性抗原的性质或它们引起的免疫反应。因为 细胞介导的免疫效应机制在获得 对其他原生动物感染的保护性免疫，我们建议研究 巴贝斯虫特异性T细胞与巴贝斯虫蛋白的相互作用 使用牛T细胞克隆在细胞和分子水平上检测抗原， 纯化以及重组抗原。T细胞产生细胞因子 细胞和巨噬细胞刺激后，及其对寄生虫的影响 的可行性，也将予以审查。这项建议的目的是 鉴定保护性巴贝斯虫抗原和免疫效应机制 在牛身上负责控制巴贝虫病该等资料不 用于针对该疾病的疫苗的合理设计，以及 另一些疾病，如疟疾，是由血原虫寄生虫引起的。

Hemoparasitic diseases are endemic in half of the world's livestock production areas and are the most important obstacle to the improvement of meat and milk production in developing nations. It is estimated that over 500 million cattle are at risk for babesiosis alone, and despite decades of research, there is still no effective, practical and safe means of immunizing livestock against this disease. The pathology of Babesia bovis infection in cattle is very similar to that caused by Plasmodium falciparum infection in humans, and is characterized by a generalized circulatory disturbance and sequestration of parasitized erythrocytes in the capillary beds, especially in the brain. The feasibility of developing a successful babesial vaccine is based on observations that recovery from an acute infection is associated with development of protective immunity, and that immunization with crude parasite extracts can induce partial protection against subsequent challenge. However, very little is known about the nature of protective antigens or the immune responses they evoke. Because cell-mediated immune effector mechanisms are crucial in obtaining protective immunity against other protozoan infections, we propose to study the interactions of Babesia-specific T cells and defined babesial protein antigens at the cellular and molecular level using bovine T cell clones and purified as well as recombinant antigens. The production of cytokines by T cells and macrophages following stimulation, and their effect on parasite viability, will also be examined. The intent of this proposal is to identify protective babesial antigens and immunologic effector mechanisms in cattle responsible for controlling babesiosis. Such information is useful for the rational design of a vaccine against this disease as well as others, such as malaria, caused by hemoprotozoan parasites.