Immunization-induced AMI and CMI against malaria

描述(由申请人提供)：通过接种疫苗控制恶性疟疾将需要使用多种有效组合的寄生虫抗原进行免疫。在这一点上，在血期裂殖子表面表达的蛋白质作为疫苗靶标很有吸引力，因为它们在红细胞侵袭和获得血清抗体方面具有重要的功能。然而，由于对保护反应的了解不足，以及缺乏这种免疫的可测量相关性，基于裂殖子抗原的疫苗在人体试验方面的进展一直受到阻碍。本应用的目的是确定两种裂殖子表面蛋白AMA-1(顶膜抗原-1)和MSP-1(裂殖子表面蛋白-1)免疫的保护性免疫参数。由于单独使用AMA-1或MSP-1免疫的最佳配方可能不同，我们的重点将放在对联合抗原免疫有效的配方上。我们有一个简单、可行的系统，使用重组AMA-1和MSP-1的组合来免疫小鼠对抗查鲍迪疟原虫。良好的B细胞反应和显著的抗体产生是保护所必需的，使用明矾或奎尼尔A作为佐剂可以实现这一点。然而，攻击前抗体效价本身并不能预测保护效果。此外，在B细胞缺陷小鼠中的研究揭示了一种抗体不依赖的细胞介导成分对Pc MSP-1诱导的保护作用。我们将检查抗体的特异性、浓度、同型和亲和力，以确定预测保护效果的可测量参数。通过大规模DNA微阵列分析，我们将确定Pc AMA-1+Pc MSP-1免疫和保护动物与完全感染查巴迪疟原虫小鼠的CD4+T细胞的基因表达谱。Pc AMA-1+Pc MSP-1在体外诱导的保护性T细胞和B细胞反应的相关性将通过被动免疫研究和选定的免疫基因敲除小鼠在体内得到验证。我们预计，随着AMA-1和MSP-1的联合制剂进入临床试验，所获得的信息可以用于评估Aotus猴子和人类的免疫反应。

DESCRIPTION (provided by applicant): The control of Plasmodium falciparum malaria by vaccination will require immunization with multiple parasite antigens effectively formulated in combination. In this regard, proteins expressed on the surface of blood-stage merozoites are attractive as vaccine targets given their functional importance in the invasion of erythrocytes and accessibility to serum antibodies. However, progress toward human trials of merozoite antigen based vaccines has been hampered by an inadequate understanding of protective responses and a lack of measurable correlates of that immunity. The objective of this application is to define parameters of protective immunity targeted by vaccination with two merozoite surface proteins, apical membrane antigen-1 (AMA-1) and merozoite surface protein-1 (MSP-1). Since optimal formulations for immunizations with AMA-1 or MSP-1 alone may differ, our focus will be on formulations that are effective for combined antigen immunizations. We have a simple, workable system using combinations of recombinant AMA-1 and MSP-1 to immunize mice against Plasmodium chabaudi malaria. A good B cell response and significant antibody production are necessary for protection and can be achieved utilizing Alum or Quil A as adjuvant. However, prechallenge antibody titers alone are not predictive of protective efficacy. Furthermore, studies in B cell deficient mice revealed an antibody independent, cell mediated component to Pc MSP-1 induced protection. We will examine antibody specificity, concentration, isotype and avidity to define measurable parameters that predict protective efficacy. By large-scale DNA microarray analyses, we will determine gene expression profiles of CD4+ T cells from Pc AMA-1 + Pc MSP-1 immunized and protected animals compared to those from mice fully susceptible to P. chabaudi malaria. Correlates of Pc AMA-1 + Pc MSP-1 induced protective T cell and B cell responses defined in vitro will be validated in vivo by passive immunization studies and through the immunization of selected immunological knockout mice. We expect that the information gained can be applied to the evaluation of immune responses in Aotus monkeys and humans as combined formulations of AMA-1 and MSP-1 move into clinical trials.