Optimizing Immunogenicity of Lactobacillus as a 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。乳酸杆菌是人类胃肠道的一种非常常见的寄生菌，商业上用于加工和保存食物，因此它是安全的，不太可能刺激抗载体免疫应答。乳酸杆菌易于生产、储存，并且由于功能基因组学已被充分理解，因此可高度操作。众所周知的益生菌活性至少部分是由于乳杆菌与树突细胞的相互作用。乳酸杆菌激活DC并刺激细胞因子产生，导致T细胞的Th 1极化。我们已经进行了初步的免疫原性研究，并证明了使用乳杆菌作为HIV-1疫苗载体的原理证明，但必须进一步优化载体以增加免疫原性。在这里提出的研究中，我们将调查宿主/载体的相互作用，以确定动力学和重组乳酸杆菌的胃肠道定植的位置，以及重组蛋白的表达是否影响土著植物群。将确定HIV-1抗原表达的最佳亚细胞位置，并在小鼠中对粘膜和全身体液和细胞免疫应答进行全面评估。为了进一步增加免疫原性，鞭毛蛋白将由乳杆菌表达，作为通过TLR 5刺激增加胃肠道中先天免疫激活的方法。这些研究将共同确定乳酸杆菌是否值得进一步开发作为抗HIV-1的口服疫苗载体。公共卫生相关性：这些研究的目的是利用乳酸杆菌开发一种新的HIV疫苗策略。使用乳酸杆菌的疫苗是安全的，生产成本低，并且可以口服。如果成功，这一战略将对艾滋病毒预防产生重大影响。

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. Lactobacillus is a very common commensal of the human gastrointestinal tract and is used commercially to process and preserve food, thus it is safe and unlikely to stimulate anti-vector immune responses. Futhermore, Lactobacillus is easy to manufacture, store and is highly manipulatable as the functional genomics are well understood. The well-known probiotic activities are due at least in part to the interaction of Lactobacillus with dendritic cells. Lactobacillus activates DC and stimulates cytokine production that leads to Th1 polarization of T cells. We have performed preliminary immunogenicity studies and demonstrated proof-of-principle for the use of Lactobacillus as a vaccine vector against HIV-1 but the vector must be further optimized to increase immunogenicity. In the studies proposed here, we will investigate the host/vector interaction to determine the kinetics and location of gastrointestinal colonization by recombinant Lactobacillus and whether recombinant protein expression affects the indigenous flora. The optimal subcellular location for HIV-1 antigen expression will be determined and a comprehensive assessment of mucosal and systemic humoral and cellular immune responses will be performed in mice. To further increase immunogenicity, flagellin will be expressed by the Lactobacillus as a method to increase innate immune activation in the gastrointestinal tract via TLR5 stimulation. Together these studies will determine whether Lactobacillus is worth further development as an oral vaccine vector against HIV-1. PUBLIC HEALTH RELEVANCE: The purpose of these studies is to develop a novel HIV vaccine strategy using Lactobacillus. A vaccine using lactobacilli would be safe, inexpensive to manufacture, and could be delivered orally. If successful, this strategy could have a significant impact on HIV prevention.