Recombinant Lactobacillus as an Oral Mucosal Vaccine Against HIV-1

描述（由申请方提供）：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应答。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。加氏乳杆菌是人口腔和胃肠道的常见寄生菌，并且可以特别用作抗HIV-1的口腔粘膜疫苗载体。L.加塞里菌在口腔中定植，并作为肠道定植的来源。此外，L. gasseri激活树突状细胞并刺激导致T细胞Th 1极化的细胞因子产生。初步研究表明，重组L.表达HIV-1 Gag的gasseri在单次口服剂量后诱导了血清IgG、粘膜伊加和结肠和生殖道中测量的细胞介导的应答。在这里，我们建议更好地确定剂量，分布和持久性L。gasseri口服免疫后。然后我们将改进L。gasseri作为免疫原，通过共表达鞭毛蛋白作为通过TLR 5刺激先天免疫系统的手段，并确定L. gasseri可以递送用于真核表达Env的DNA疫苗。调节性T细胞在粘膜免疫中的作用将通过伴随口服免疫的Treg耗竭来评估。最后，将进行稳健性挑战研究，以确定L。gasseri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粘膜相关淋巴组织，可以使用统计学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进行致病性FIV阴道攻毒。项目叙述：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应答。加氏乳杆菌是在人类口腔和胃肠道中发现的常见益生菌，因此可能是针对HIV-1的特别有效的疫苗载体。本研究将探讨重组L. gasseri，可以通过口腔粘膜诱导针对HIV-1的保护性免疫应答。

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.