Recombinant Lactobacillus as an Oral Mucosal Vaccine Against HIV-1

描述（由申请人提供）：HIV-1的传播主要发生在粘膜表面，因此成功的HIV-1疫苗必须诱导粘膜体液和细胞免疫反应。几个世纪以来，乳酸菌一直被用于加工和保存食品，并以其益生菌活性而闻名。最近，乳酸菌家族的成员已被探索作为疫苗载体。加色乳杆菌是人类口腔和胃肠道的常见共生菌，可能特别有用，作为抗HIV-1的口腔黏膜疫苗载体。L. gasseri在口腔定植，并作为肠道定植的来源。此外，L. gasseri激活树突状细胞，刺激细胞因子的产生，导致T细胞的Th1极化。在初步研究中，单次口服剂量后，表达HIV-1 Gag的重组L. gasseri诱导结肠和生殖道中血清IgG、粘膜IgA和细胞介导的反应。为了更好地确定口服免疫后加氏乳杆菌的剂量、分布和持续时间。然后，我们将通过共同表达鞭毛蛋白作为一种通过TLR5刺激先天免疫系统的手段来完善L. gasseri作为一种免疫原，并确定L. gasseri是否可以为真核表达Env提供DNA疫苗。调节性T细胞在粘膜免疫中的作用将通过消耗Treg同时进行口服免疫来评估。最后，一个强大的挑战研究将进行，以确定是否l.g asseri可以诱导保护性免疫。这些研究将使用HIV-1的猫/FIV模型进行，因为猫具有与人类相似的口咽黏膜相关淋巴组织，可以使用统计相关数字进行经济研究，并且可以使用细胞相关和无细胞病毒阴道感染致病性FIV。项目说明：HIV-1的传播主要发生在粘膜表面，因此成功的HIV-1疫苗必须诱导粘膜体液和细胞免疫反应。乳酸菌是一种常见的益生菌，存在于人类口腔和胃肠道中，因此可能是一种特别有效的HIV-1疫苗载体。本文提出的研究将探讨设计重组加氏乳杆菌的策略，该重组加氏乳杆菌可以通过口腔黏膜诱导针对HIV-1的保护性免疫反应。

DESCRIPTION (provided by applicant): Transmission of HIV-1 occurs predominately at mucosal surfaces and therefore a successful vaccine against HIV-1 must induce mucosal humoral and cellular immune responses. Lactic acid bacteria have been used for centuries to process and preserve food and are well known for their probiotic activities. Recently members of the lactic acid bacteria family have been explored as vaccine vectors. Lactobacillus gasseri is a common commensal of the human oral cavity and gastrointestinal tract and may be particularly useful as an oral mucosal vaccine vector against HIV-1. L. gasseri colonizes the oral cavity and serves as a source for colonization of the intestinal tract. In addition, L. gasseri activates dendritic cells and stimulates cytokine production that leads to Th1 polarization of T cells. In preliminary studies, recombinant L. gasseri expressing HIV-1 Gag induced serum IgG, mucosal IgA and cell mediated responses measured in the colon and reproductive tract after a single oral dose. Here we propose to better determine the dose, distribution and persistence of L. gasseri after oral immunization. We will then refine L. gasseri as an immunogen by co-expressing flagellin as a means to stimulate the innate immune system through TLR5 and determining whether L. gasseri can deliver a DNA vaccine for the eukaryotic expression of Env. The role of regulatory T cells in mucosal immunization will be assessed by depleting Treg concomitant with oral immunization. Finally, a robust challenge study will be performed to determine whether L. gasseri can induce protective immunity. These studies will be performed using the cat/FIV model of HIV-1 since cats have oropharyngeal mucosa associated lymphoid tissue similar to humans, can be economically studied using statistically relevant numbers, and can be vaginally challenged with pathogenic FIV using cell-associated and cell-free virus. Project Narrative: Transmission of HIV-1 occurs predominately at mucosal surfaces and therefore a successful vaccine against HIV-1 must induce mucosal humoral and cellular immune responses. Lactobacillus gasseri is a common probiotic bacterium found in the human oral cavity and gastrointestinal tract and as such may be a particularly effective vaccine vector against HIV-1. Studies proposed here will investigate strategies to engineer recombinant L. gasseri that can induce a protective immune response against HIV-1 via the oral mucosa.