Ogonczyk-Makowska Daniela, Fasquelle François, Vreulx Anaïs-Camille, Scuotto Angelo, Degraeve Amélie, Thiroux Bryan, Martin Louise Françoise, Tahas Stamatios Alan, Jakobsen Jeanne Toft, Jungersen Gregers, Betbeder Didier
Vaxinano SAS, 84 Rue Du Dr Yersin, 59120, Loos, France.
Copenhagen ZOO, Roskildevej 32, 2000, Frederiksberg, Denmark.
Int J Parasitol Parasites Wildl. 2024 Nov 7;25:101017. doi: 10.1016/j.ijppaw.2024.101017. eCollection 2024 Dec.
is a ubiquitous parasite causing significant mortality in captive wildlife, especially marsupials. Historically, treatment has been unrewarding and no vaccine was available. An intranasal vaccine based on purified inactivated was developed for toxoplasmosis prevention. A vaccination campaign started in early 2017 and was successful in preventing toxoplasma-related mortality in marsupials in many European and South American zoos. Amongst the vaccinated wallabies, about 30% were T. gondii seropositive before the vaccination, and no toxoplasma-related deaths were observed since the administration of the vaccine. The objective of this case study was to assess the potential effect of the vaccination on a seropositive wallaby. It is important to note that this vaccine doesn't induce any humoral response in sheep, and squirrel monkeys but induces a strong T-cell response. A seropositive Yellow-footed rock wallaby () from Copenhagen Zoo received two doses of the aforementioned intranasal vaccine. Blood samples were collected before each vaccination and used for peripheral blood mononuclear cell isolation. The impact of the vaccination on the lymphocyte phenotype was characterized by flow cytometry. Cell size, represented by forward scatter, and granularity, represented by side scatter parameters were analyzed. Two doses of the vaccine induced a respective 30.1 and 25.6% increase in cell size and granularity in lymphocytes stimulated with antigens, as assessed by flow cytometry. These changes were likely correlated with T-cell activation, which indicates that two doses of the vaccine might have boosted the already-existing T-cell memory response against in a seropositive animal. No morphological changes were observed in lymphocytes from an unvaccinated seronegative wallaby. This is the first documented case of boosting an already-existing cellular immune response against toxoplasmosis by the vaccine in a seropositive Yellow-footed rock wallaby.
是一种普遍存在的寄生虫，在圈养野生动物尤其是有袋动物中导致大量死亡。从历史上看，治疗一直没有成效，也没有可用的疫苗。一种基于纯化灭活的鼻内疫苗被开发用于预防弓形虫病。2017年初开始了一项疫苗接种运动，成功地预防了许多欧洲和南美洲动物园中有袋动物的弓形虫相关死亡。在接种疫苗的沙袋鼠中，约30%在接种前弓形虫血清呈阳性，自接种疫苗以来未观察到与弓形虫相关的死亡。本案例研究的目的是评估疫苗接种对一只血清阳性沙袋鼠的潜在影响。需要注意的是，这种疫苗在绵羊和松鼠猴中不会诱导任何体液反应，但会诱导强烈的T细胞反应。一只来自哥本哈根动物园的血清阳性黄脚岩袋鼠（）接受了两剂上述鼻内疫苗。在每次接种前采集血样，用于分离外周血单个核细胞。通过流式细胞术表征疫苗接种对淋巴细胞表型的影响。分析了以前向散射表示的细胞大小和以侧向散射参数表示的颗粒度。通过流式细胞术评估，两剂疫苗分别使受抗原刺激的淋巴细胞的细胞大小和颗粒度增加了30.1%和25.6%。这些变化可能与T细胞活化相关，这表明两剂疫苗可能增强了血清阳性动物中已有的针对的T细胞记忆反应。在未接种疫苗的血清阴性沙袋鼠的淋巴细胞中未观察到形态变化。这是首次有文献记载在血清阳性黄脚岩袋鼠中通过疫苗增强已有的针对弓形虫病的细胞免疫反应的案例。
