Tracking Immune Activation by Stress Proteins In Vivo

描述（由申请人提供）：含有与应激蛋白相关肽的疫苗是已知最有效的T细胞免疫原。然而，它们激活免疫细胞的确切机制尚不清楚。为了解决这一问题，我们将在免疫了与应激蛋白hsp70融合的抗原的小鼠中追踪活化的树突状细胞（dc）和CD8+ T细胞，并确定哪些细胞因子和细胞表面受体是它们反应所必需的。我们的初步研究表明，hspTO融合疫苗比单独抗原或与其他佐剂相比，可引起更有效和持久的特异性CD8+ T细胞反应。我们的基本假设是抗原/hsp70融合物是有效的疫苗，因为它们刺激dc为CD8+ T细胞激活提供最佳微环境。这种微环境的特点是高抗原密度和强共刺激。为了验证这一点，我们将跟踪体内DC和CD8+ T细胞在引流淋巴结中的反应，以及由此产生的外周效应和记忆CD8+ T淋巴细胞。我们的建议的新方面包括：1)量化活化的DC呈递抗原的数量，2)hsp70融合蛋白对DC寿命的影响，3)确定几种报道的hsp70受体中哪些是必要的或足够的，以向体内DC传递激活信号，以及4)确定我们的疫苗具有CD8+ T细胞记忆的深远影响所需的共刺激和细胞因子。这些实验的结果将使我们能够合理地操纵应激蛋白诱导的反应，最终目标是最大限度地利用它们用于癌症治疗。

DESCRIPTION (provided by applicant): Vaccines containing peptides linked to stress proteins are the most potent known T cell immunogens. However, the precise mechanisms by which they activate immune cells remain unclear. To address this, we will track activated dendritic cells (DCs) and CD8+ T cells in mice immunized with antigens fused to the stress protein hsp70, and determine which cytokines and cell surface receptors are required for their responses. Our preliminary studies reveal hspTO fusion vaccines elicit much more potent and durable specific CD8+ T cell responses than antigen alone or with other adjuvants. Our underlying hypothesis is that antigen/hsp70 fusions are potent vaccines because they stimulate DCs to provide an optimal microenvironment for CD8+ T cell activation. This microenvironment is defined by high antigen density and strong costimulation. To test this, we will track in vivo DC and CD8+ T cell responses in draining lymph nodes, and the resultant effector and memory CD8+ T lymphocytes in the periphery. Novel aspects of our proposal include: 1) quantifying the amount of antigen presented by activated DCs, 2) the effect hsp70 fusion proteins have on DC lifespan, 3) determining which of the several reported hsp70-receptors are necessary or sufficient for delivering activation signals to DCs in vivo, and 4) determining the costimulatory and cytokines required for the profound effect our vaccine has CD8+ T cell memory. The results of these experiments will allow us to manipulate stress protein-induced responses rationally with the ultimate goal of maximizing their use for cancer therapy.