Doherty M L, Bassett H F, Quinn P J, Davis W C, Monaghan M L
Faculty of Veterinary Medicine, University College Dublin, Ballsbridge, Ireland.
Am J Vet Res. 1995 Oct;56(10):1300-6.
Systemic administration of dexamethasone led to a significant reduction in the size of the tuberculin reaction in response to intradermal injection of bovine purified protein derivative in 18 cattle experimentally sensitized to Mycobacterium bovis (P < 0.01) and 8 cattle naturally infected with M bovis (P < 0.001). The reaction in 6 of the 7 M bovis infected cattle that received dexamethasone was classified as negative for the standard interpretation of the single intradermal comparative tuberculin test. Significantly fewer BoCD2+ (P < 0.05) and BoCD4+ T cells (P < 0.001) were present at the reaction site and in blood of dexamethasone-treated cattle, compared with untreated control cattle. Significantly fewer cells expressing the interleukin-2 receptor and WC1+ gamma delta T cells (P < 0.001), and a significantly greater number of cells expressing the ACT2 antigen (P < 0.05) were found at the reaction site in dexamethasone treated cattle than in controls. The number of BoCD8+ T cells at the reaction site and in blood was not significantly affected by administration of dexamethasone. In vitro production of interferon-gamma by lymphocytes incubated with bovine purified protein derivative also was significantly lower (P < 0.01) in the dexamethasone treated cattle.
对18头经实验感染牛分枝杆菌致敏的牛以及8头自然感染牛分枝杆菌的牛进行皮内注射牛纯化蛋白衍生物，然后全身性给予地塞米松，结果发现结核菌素反应大小显著减小（实验致敏牛中P < 0.01，自然感染牛中P < 0.001）。在接受地塞米松治疗的7头感染牛分枝杆菌的牛中，有6头牛的反应按照单次皮内比较结核菌素试验的标准解读被判定为阴性。与未治疗的对照牛相比，地塞米松治疗的牛的反应部位和血液中的BoCD2 +（P < 0.05）和BoCD4 + T细胞（P < 0.001）显著减少。在地塞米松治疗的牛的反应部位发现，表达白细胞介素-2受体的细胞和WC1 + γδ T细胞显著减少（P < 0.001），而表达ACT2抗原的细胞数量显著增加（P < 0.05）。地塞米松的给药对反应部位和血液中的BoCD8 + T细胞数量没有显著影响。在地塞米松治疗的牛中，与牛纯化蛋白衍生物一起孵育的淋巴细胞体外产生干扰素-γ的能力也显著降低（P < 0.01）。
