Department of Morphology and Pathology, Graduate Program in Evolutionary Genetics and Molecular Biology Federal, University of São Carlos (UFSCar), São Carlos (SP), Brazil,
Department of Genetics and Evolution, Graduate Program in Evolutionary Genetics and Molecular Biology, Federal University of São Carlos (UFSCar), São Carlos (SP), Brazil.
Cell Physiol Biochem. 2023 Oct 9;57(5):379-394. doi: 10.33594/000000664.
BACKGROUND/AIMS: Swine erysipelas is a disease caused by , a Gram-positive bacillus, which has great economic importance because it leads to the loss of the swine herd. To control this disease, animals are immunized with a cellular vaccine of killed or attenuated , but even with herd vaccination, cases of swine erysipelas outbreaks have been reported in the United States, China and Japan, leading to the search for other antigenic components of the bacteria that may promote greater protection against . The surface protein SpaA from has been shown to be a candidate to constitute a subunit vaccine, since it has already been reported to induce a host immune response against the bacterium. DnaK, a hsp70 molecular chaperone, also seems to be a good candidate in the composition of a vaccine, as it has been demonstrated to be an antigenic protein of the bacteria.
This work evaluated the immunogenicity and protection induced by the e SpaA and DnaK recombinant proteins in a murine model, by intramuscular administration to mice with two doses of 100 µg at 21-day interval between them. The candidate proteins were tested either separately and together, compared with the commercial vaccine and the non-vaccination condition, and mice were challenged with a virulent strain of . Serum was collected to assess the produced antibodies and peripheral blood cells, whereas spleen and kidney tissues were assayed for presence by colony counting.
A survival curve of the animals was performed, which confirmed the protection induced by the proteins. IgG antibodies increased in the animal serum inoculated with the proteins when compared to the control, and a significant delay in disease symptoms was observed.
These results suggest that DnaK and SpaA are immunogenic in mice and interfere with the disease development.
背景/目的：猪丹毒是由革兰氏阳性杆菌引起的疾病，具有重要的经济意义，因为它会导致猪群的损失。为了控制这种疾病，动物用细胞疫苗（杀死或减毒的）进行免疫接种，但即使进行了群体免疫接种，在美国、中国和日本仍有猪丹毒爆发的病例报告，这导致人们寻找该细菌的其他抗原成分，以促进对其的更大保护。已经表明，来自的表面蛋白 SpaA 是构成亚单位疫苗的候选物，因为它已经被报道能诱导宿主对细菌的免疫反应。热休克蛋白 70 分子伴侣 DnaK 似乎也是疫苗成分的一个很好的候选物，因为它已被证明是细菌的一种抗原蛋白。
本工作通过肌肉内给药，在小鼠模型中评估了 e SpaA 和 DnaK 重组蛋白的免疫原性和保护作用，每 21 天间隔给予两次 100 µg 的剂量。候选蛋白分别和一起进行了测试，与商业疫苗和非接种条件进行了比较，并对小鼠进行了强毒菌株的攻毒。收集血清以评估产生的抗体和外周血细胞，而脾脏和肾脏组织则通过集落计数来检测的存在。
对动物进行了生存曲线分析，证实了这些蛋白诱导的保护作用。与对照组相比，用蛋白接种的动物血清中的 IgG 抗体增加，并且观察到疾病症状出现明显延迟。
这些结果表明，DnaK 和 SpaA 在小鼠中具有免疫原性，并能干扰疾病的发展。
