Xu Bohuai, Zhang Xiuqiang, Wang Yaowen, Chen Jia
The First Affiliated Hospital of Ningbo University, Ningbo 315000, China.
Health Science Center, Ningbo University, Ningbo 315211, China.
Microorganisms. 2025 Jul 14;13(7):1661. doi: 10.3390/microorganisms13071661.
, a parasitic protozoan, causes zoonotic infections with severe health impacts in humans and warm-blooded animals, underscoring the urgent need for effective vaccines to control these infections. In this study, a DNA vaccine encoding TgROP5, TgROP18, TgGRA7, TgGRA15, and TgMIC6 was formulated using the eukaryotic expression vector pVAX I. IL-24 was delivered as a molecular adjuvant using plasmid pVAX-IL-24. BALB/c, C57BL/6, and Kunming mouse strains received the DNA immunization, after which antibody levels, cytokine production, and lymphocyte surface markers were analyzed to assess immune responses. Additionally, survival rates and brain cyst counts were measured 1 to 2 months post-vaccination in experimental models of toxoplasmosis. As a result, compared to controls, the DNA vaccine cocktail significantly increased serum IgG levels, Th1 cytokine production, and proportions of CD4+/CD8+ T cells, leading to extended survival and reduced brain cyst counts post-challenge with ME49. Furthermore, the five-gene DNA vaccine cocktail conferred greater protection compared to single-gene immunizations. Co-administration of IL-24 significantly enhanced the immune efficacy of the multi-gene DNA vaccination. Our findings suggest that IL-24 is an effective molecular adjuvant, enhancing the protective immunity of DNA vaccines against , supporting its potential role in vaccine strategies targeting other apicomplexan parasites.
弓形虫是一种寄生原生动物，可导致人畜共患感染，对人类和温血动物的健康产生严重影响，这凸显了迫切需要有效的疫苗来控制这些感染。在本研究中，使用真核表达载体pVAX I构建了一种编码TgROP5、TgROP18、TgGRA7、TgGRA15和TgMIC6的DNA疫苗。使用质粒pVAX-IL-24将IL-24作为分子佐剂。BALB/c、C57BL/6和昆明小鼠品系接受了DNA免疫，之后分析抗体水平、细胞因子产生和淋巴细胞表面标志物以评估免疫反应。此外，在弓形虫病实验模型中，在接种疫苗后1至2个月测量存活率和脑囊肿数量。结果，与对照组相比，DNA疫苗混合物显著提高了血清IgG水平、Th1细胞因子产生以及CD4+/CD8+ T细胞比例，导致在用ME49攻击后存活期延长且脑囊肿数量减少。此外，与单基因免疫相比，五基因DNA疫苗混合物提供了更大的保护。IL-24的共同给药显著增强了多基因DNA疫苗接种的免疫效果。我们的研究结果表明，IL-24是一种有效的分子佐剂，可增强DNA疫苗对弓形虫的保护性免疫，支持其在针对其他顶复门寄生虫的疫苗策略中的潜在作用。
