Safety and potency studies of HIV DNA vaccines

总结： 由于体液和细胞以及免疫应答对于AIDS可能都是重要的，因此构建了两种HIV-1多基因质粒DNA，其含有在人CMV和鼠内源性AKV启动子调控下的来自pNL 4 -3 DNA的gag和env基因。 通过恒河猴和猪尾猕猴的直接DNA注射来分析体液和T细胞增殖免疫应答的发展。在恒河猴中，两种DNA均产生了相似水平的T细胞增殖反应，而恒河猴和猪尾猕猴中的体液反应与疫苗DNA的启动子强度直接相关。与AKV-DNA相比，使用更少量和更少的CMV-DNA注射产生对Gag和Env的长期可加强抗体。破伤风类毒素注射用于证明动物对已知抗原的类似应答能力。 为了评估针对HIV-1的保护，用寡聚gp 160的单次注射加强DNA接种的猪尾猕猴和恒河猴（以增强env应答）。在加强后4周评价Env抗体应答表明，与对照动物相比，HIV-1 DNA接种动物中对gp 120和gp 41的抗体滴度增加。未检测到中和抗体。用SHIV-IIIb攻击恒河猴。在蛋白加强后4周，HIV-1 DNA疫苗+蛋白免疫导致血浆病毒RNA减少，表明动物受到部分保护。用HIV-1攻击猪尾猕猴。HIV-1 DNA接种动物的血浆病毒载量分析表明，在接种CMV-HIV DNA的动物中，通过bDNA PCR检测不到病毒。研究正在进行中，以调查PBMC中的病毒序列，以确定在DNA疫苗接种的动物中是否实现完全保护。

Summary: Since both humoral and cellular and immune responses may be important against AIDS, two HIV-1 multigenic plasmid DNAs were constructed containing the gag and env genes from pNL4-3 DNA under the regulation of the human CMV and murine endogenous AKV promoters. Development of humoral and T cell proliferative immune responses were analyzed by direct DNA injection of rhesus and pig-tailed macaques. Similar levels of T-cell proliferative responses were generated with both DNAs in rhesus macaques whereas the humoral responses in rhesus and pig-tailed macaques correlated directly with the promoter strength of the vaccine DNA. Long-term, boostable antibodies to Gag and Env were generated using less amount and fewer injections of CMV-DNA than with AKV-DNA. Tetanus toxoid injection was used to demonstrate ability of the animals to respond similarly to a known antigen. To evaluate protection against HIV-1, DNA vaccinated pig-tailed and rhesus macaques were boosted with a single injection of oligomeric gp160 (to enhance the env response). Evaluation of the Env antibody responses at 4 weeks post-boost indicated increased antibody titers to gp120 and gp41 in the HIV-1 DNA vaccinated animal as compared with the control animals. No neutralizing antibodies were detected. The rhesus macaques were challenged with SHIV-IIIb. At 4 weeks post-protein boost, the HIV-1 DNA vacine + protein immunization resulted in reduction of plasma viral RNA indicating that the animals were partially protected. Pig-tailed macaques were challenged with HIV-1. Plasma viral load analysis of the HIV-1 DNA vaccinated animals demonstrated absence of detectable virus by bDNA PCR in animals vaccinated with the CMV-HIV DNA. Studies are underway to investigate viral sequences in the PBMCs to determine whether complete protection was achieved in the DNA vaccinated animals.