Translation Research in Plasmodium vivax

本研究的目的是鉴定和描述针对间日疟原虫抗原的保护性免疫反应，这些抗原来自疟原虫的红细胞前和蚊子阶段。然后研制疫苗，诱导这些免疫反应，并在猕猴模型中提供保护。(A)将在终身接触间日疟原虫疟疾的流行地区的居民和接受辐照间日疟原虫孢子虫免疫的志愿者中确定被认为参与保护的免疫反应，并证明这些免疫反应可防止孢子虫的攻击。(b)保护性生物活性的测试将在体内通过评估猕猴和人类志愿者的寄生虫血症进行，在体外通过评估血清抑制孢子子侵入肝细胞、肝细胞培养中孢子子的发育和血期培养中血期发育的能力，以及通过评估白按蚊以含配子体的血期培养物为食的卵囊发育来进行。(c)受保护个体和未受保护个体的血清将通过孢子体、肝脏和血液阶段的IFAT以及利用选定的全长重组蛋白、长肽或成分表位的ELISA进行表征。我们将首先关注可用的试剂：PvSP和PvSSP2/TRAP（孢子子和肝期抗原），pvvmsp -1和PvDBP（血期抗原）和Pvs25/28（蚊子肠道中表达的抗原）。其他抗原将在可用时进行研究。淋巴细胞对PvCSP和PvSSP2（以及由各种佐剂、DNA质粒、重组痘病毒和猴子模型配制的蛋白或肽）的表位产生的CTL和干扰素γ反应将通过ELISPOT进行表征。我们将利用血期攻毒模型和新开发的孢子虫攻毒模型。这个研究项目将整合过去十年在哥伦比亚西部精心开发的实验室、灵长类动物设施、昆虫和实地站点的使用，以回答关于这种重要但相对被忽视的疟疾寄生虫的这些关键生物学问题。

The purpose of the research described in this proposal is to identify and characterize protective immune responses against defined and newly discovered Plasmodium vivax antigens from the pre-erythrocytic and mosquito stages of the parasite., and then to formulate vaccines that induce these immune responses and provide protection in the Aotus monkey model. (A) Immune responses thought to be involved in protection will be identified in residents of endemic areas with life-long exposure to P. vivax malaria and also in volunteers immunized with irradiated P. vivax sporozoites and shown to be protected against sporozoite challenge. (b) Testing for protective biological activity will be done in vivo by assessing parasitemia in Aotus monkeys and in human volunteers, and in vitro by assessing the ability of sera to inhibit sporozoite invasion of hepatocytes, development of sporozoites in hepatocyte culture, and development of blood stages in blood stage culture, and by assessing oocyst development in Anopheles albimanus fed on blood stage cultures containing gametocytes. (c) Sera from protected and non protected individuals will be characterized by sporozoite, liver and blood stage IFAT and by ELISA utilizing selected full length recombinant proteins, long peptides or components epitopes. We will focus initially on reagents that are available: PvSP and PvSSP2/TRAP (sporozoite and liver stage antigens), PvMSP-1 and PvDBP (blood stage antigens) and Pvs25/28 (antigens expressed in the mosquito gut). Other antigens will be studied as they become available. Lymphocytes will be characterized by CTL and interferon gamma production by ELISPOT in response to epitopes derived from the PvCSP and PvSSP2 (and from proteins or peptides formulated with various adjuvants, DNA plasmids, and recombinant poxviruses, and monkey models. We will utilize the blood stage challenge model in Aotus and a newly developed sporozoite challenge model in Aotus. This research project will integrate the use of laboratories, primate facilities, insectories and field sites painstakingly developed over the last decade in western Columbia in order to answer these critical biological questions about this important but relatively neglected malaria parasite.