Understand B Cell Immunity Against HIV-1 gp41 MPER

项目2的研究人员将专注于评估针对不同平台提供的gp41-MPER抗原的B细胞免疫反应。具体目标是： 目的1.比较B细胞对单价和多价gp41MPER抗原的反应。利用AIMS 1和AIMS 2中开发的多价抗原递送平台，我们将在定性和定量上检验我们的假设，即多价抗原能够诱导优于单价抗原的抗体反应。我们还将测试第二个假设，即通过免疫多个表位可以优先诱导针对特定表位(例如2F5或4E10表位)的更强抗体反应。 同一抗原的变异体，其中所有变异体中唯一保守的元件是目标表位。 目的2.通过共刺激分子的共提呈增强B细胞免疫应答。我们的目标是利用共刺激分子增强对多价抗原的抗体反应。在这方面，我们将检验我们的假设，即与作为自由分子存在时相比，当共刺激分子与抗原物理连接时(如在我们的递送平台中)，针对抗原的抗体反应将被更大程度地刺激。我们将评估CDI54和BLyS的刺激作用。 目的3.比较不同gp41免疫原在体内诱导TFH和GC反应的能力。使用gp41MPER多聚体与项目1中描述的不同传递平台(GNP或基于DNA的阵列)以及本项目目标2中描述的协同刺激相结合，我们的目标将是评估免疫后体内CD4+T辅助细胞和B细胞的反应。具体地说，我们将用每一种改造的gp41疫苗来挑战小鼠，并测量单次暴露后T滤泡辅助细胞(TFH)和生发中心(GC)的反应，以及单次或多次暴露后的记忆B细胞反应 这些发现将与AIMS 1和2中测量的抗gp41抗体反应相关联。

Investigators in Project 2 will focus on evaluation of B cell immune responses against gp41-MPER antigens being delivered by different platforms. The specific aims are: Aim 1. To compare B cell responses to monovalent vs. multivalent gp41 MPER antigens. Using multivalent antigen delivery platforms developed in Aims 1 and 2, we will test our hypothesis that multivalent antigens are capable of inducing antibody responses that are superior to monovalent antigens, qualitatively and quantitatively. We will also test a second hypothesis that it is possible to preferentially elicit stronger antibody responses towards a particular epitope (e.g. 2F5 or 4E10 epitopes) by immunizing with multiple variants of the same antigen where the only conserved element amongst all the variants is the target epitope. Aim 2. To enhance B cell immune responses by co-presentation of costimulatory molecules. Our goal is to enhance antibody responses against multivalent antigens using costimulatory molecules. In this regard, we will test our hypothesis that antibody responses against antigens will be stimulated to a greater extent when costimulatory molecules are physically linked to antigens (as they would be in our delivery platforms), compared to when then are presented as free molecules. We will evaluate stimulatory effects of CDI54 and BLyS. Aim 3. To compare the ability of different gp41 immunogens to elicit TFH and GC responses in vivo. Using the gp41 MPER multimers coupled with the different delivery platforms described in Project 1 (GNP or DNA based arrays) and with the co-stimuli described in Aim 2 of this Project, our goal will be to assess the in vivo CD4+ T helper cell and B cell response after immunization. Specifically, we will challenge mice with each of the engineered gp41 vaccines, and measure the T follicular helper (TFH) cell and germinal center (GC) response after a single exposure, and the memory B cell response after single or multiple exposures These findings will be correlated with anti-gp41 antibody responses measured in Aims 1 and 2.