Department of Internal Medicine, Reproduction and Population Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9820, Merelbeke, Belgium.
Vet Res. 2023 Mar 1;54(1):16. doi: 10.1186/s13567-023-01145-1.
Mycoplasma hyopneumoniae is the primary agent of enzootic pneumonia in pigs. To minimize the economic losses caused by this disease, M. hyopneumoniae vaccination is commonly practiced. However, the persistence of M. hyopneumoniae vaccine-induced immunity, especially the cell-mediated immunity, till the moment of slaughter has not been investigated yet. Therefore, on two commercial farms, 25 pigs (n = 50) received a commercial bacterin intramuscularly at 16 days of age. Each month, the presence of M. hyopneumoniae-specific serum antibodies was analyzed and the proliferation of and TNF-α, IFN-γ and IL-17A production by different T cell subsets in blood was assessed using recall assays. Natural infection with M. hyopneumoniae was assumed in both farms. However, the studied pigs remained M. hyopneumoniae negative for almost the entire trial. Seroconversion was not observed after vaccination and all pigs became seronegative at two months of age. The kinetics of the T cell subset frequencies was similar on both farms. Mycoplasma hyopneumoniae-specific cytokine-producing CD4CD8 T cells were found in blood of pigs from both farms at one month of age but decreased significantly with increasing age. On the other hand, T cell proliferation after in vitro M. hyopneumoniae stimulation was observed until the end of the fattening period. Furthermore, differences in humoral and cell-mediated immune responses after M. hyopneumoniae vaccination were not seen between pigs with and without maternally derived antibodies. This study documents the long-term M. hyopneumoniae vaccine-induced immune responses in fattening pigs under field conditions. Further research is warranted to investigate the influence of a natural infection on these responses.
猪肺炎支原体是猪地方性肺炎的主要病原体。为了将这种疾病造成的经济损失降到最低，常对猪进行支原体疫苗接种。然而，支原体疫苗诱导的免疫，特别是细胞免疫，在屠宰前的持续时间尚未得到研究。因此，在两个商业养殖场中，25 头猪（n=50）在 16 日龄时肌肉内接种了商业菌苗。每个月都分析了猪肺炎支原体特异性血清抗体的存在，并使用回忆试验评估了血液中不同 T 细胞亚群的增殖和 TNF-α、IFN-γ和 IL-17A 的产生。假设两个养殖场都发生了支原体自然感染。然而，在整个试验过程中，研究猪几乎一直保持支原体阴性。接种后未观察到血清转化，所有猪在两个月大时都转为血清阴性。两个养殖场的 T 细胞亚群频率动力学相似。在一个月大时，两个养殖场的猪血液中都发现了产生支原体细胞因子的 CD4CD8 T 细胞，但随着年龄的增长，这些细胞显著减少。另一方面，在体外刺激支原体后观察到 T 细胞增殖，直到育肥期结束。此外，在有和没有母源抗体的猪之间，支原体疫苗接种后的体液和细胞免疫反应没有差异。本研究记录了育肥猪在田间条件下长期的支原体疫苗诱导免疫反应。需要进一步研究自然感染对这些反应的影响。
