Optimized second-generation recombinant mycobacteria vaccine vectors against HIV

 描述(申请人提供)：艾滋病毒/艾滋病困扰着3300万人，迫切需要一种能够阻止艾滋病毒传播的预防性疫苗。重组卡介苗(RBCG)和污垢分枝杆菌(RSmeg)是很有前景的疫苗载体，在实验动物中被证明能诱导对多种病原体的保护性免疫。然而，有充分的证据表明，目前的分枝杆菌疫苗载体具有局限性。具有免疫原性的rBCG和rSmeg载体是不稳定的，因为它们被多拷贝和异构体表达载体转化。这些由整合的单拷贝质粒产生的分枝杆菌疫苗载体是稳定的，但不能表达足够数量的疫苗抗原来在小鼠和猴子身上诱导免疫反应。在这个方案中，我们将探索一种创新的方法，利用分枝杆菌噬菌体来产生整合熟练的表达载体，用于工程第二代rBCG和rSmeg疫苗载体，这些载体不仅稳定，而且具有明显更高的疫苗抗原表达。将在小鼠身上进行临床前免疫原性测试，以评估第二代分枝杆菌疫苗载体在诱导抗SIV免疫反应方面是否会优于旧原型。我们将把新的rBCG和rSmeg载体与重组腺病毒载体配对，以诱导强大的系统和粘膜抗体以及T细胞反应。这些临床前研究是开发新的和改进的重组卡介苗和耻垢分枝杆菌作为潜在的艾滋病和其他疾病候选疫苗载体的关键一步。

 DESCRIPTION (provided by applicant): HIV/AIDS afflicts 33 million people and a preventive vaccine that will stop transmission of HIV is desperately needed. Recombinant BCG (rBCG) and M. smegmatis (rSmeg) are promising vaccine vectors that were shown to induce protective immunity against a number of pathogens in laboratory animals. However, there is ample evidence demonstrating that current mycobacteria vaccine vectors have limitations. rBCG and rSmeg vectors that are immunogenic are unstable since they are transformed with multi-copy and episomal expression plasmids. Those mycobacteria vaccine vectors that are produced by integrative single-copy plasmids are stable but do not express sufficient amounts of the vaccine antigen to induce an immune response in mice and monkeys. In this proposal, we will explore an innovative approach by exploiting mycobacteriophages to generate integration-proficient expression plasmids for engineering second-generation rBCG and rSmeg vaccine vectors that are not only stable but also have markedly higher expression of vaccine antigens. Preclinical immunogenicity testing in mice will be conducted to assess whether the second generation mycobacteria vaccine vectors will outperform old prototypes in inducing anti-SIV immune responses. We will partner the new rBCG and rSmeg vectors with recombinant adenovirus vectors for eliciting robust systemic and mucosal antibody and T cell responses. These preclinical studies are a critical step towards developing new and improved recombinant BCG and M. smegmatis as potential candidate vaccine vectors against AIDS and other diseases.