Alzuherri H M, Woodall C J, Clarke C J
Department of Veterinary Pathology, universtiy of Edinburgh,Easter Bush, Roslin, UK.
Vet Immunol Immunopathol. 1996 Jan;49(4):331-45. doi: 10.1016/0165-2427(95)05477-4.
Mycobacterium avium subspecies paratuberculosis is an intracellular parasite of intestinal macrophages and causes a chronic granulomatous enteritis in sheep and other ruminants (paratuberculosis or Johne's disease). Macrophages can be produced a variety of immunoregulatory cytokines that may influence mycobacterial killing and produce disordered inflammation within the gut. In this study, messenger RNA (mRNA) was extracted from intestinal tissue from control and multibacillary diseased sheep and profiles for the cytokines tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), IL-6, transforming growth factor-beta1 (TGF-beta1) and granulocyte-macrophage colony stimulating factor (GM-CSF) were semi-quantified using reverse transcriptase polymerase chain reactions (RT-PCR). Infected intestinal tissues had significantly increased mRNA for TNF-alpha, IL-1beta and IL-6 but TGF-beta1 and GM-CSF mRNA levels were significantly different from controls. Supernatants from in vitro intestinal cultures were assayed for TNF-alpha activity using the PK(15)-1512 cytotoxicity bioassay and levels were significantly raised in diseased samples. TNF-alpha was not detected in any serum samples. Further analysis on intestinal tissues from sheep with the different, paucibacillary, form of the disease showed significant elevation of TNF-alpha mRNA but not other cytokines tested. Increased pro-inflammatory cytokine expression in the intestine coincident with a failed or misdirected immune response may contribute to the pathogenesis of paratuberculosis and the persistence of a chronic inflammatory state.
副结核分枝杆菌鸟亚种是肠道巨噬细胞的一种细胞内寄生虫，可在绵羊和其他反刍动物中引起慢性肉芽肿性肠炎（副结核病或约内氏病）。巨噬细胞可产生多种免疫调节细胞因子，这些细胞因子可能影响分枝杆菌的杀灭，并在肠道内引发炎症紊乱。在本研究中，从对照绵羊和多菌型患病绵羊的肠道组织中提取信使核糖核酸（mRNA），并使用逆转录聚合酶链反应（RT-PCR）对细胞因子肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、IL-6、转化生长因子-β1（TGF-β1）和粒细胞-巨噬细胞集落刺激因子（GM-CSF）的表达谱进行半定量分析。感染的肠道组织中TNF-α、IL-1β和IL-6的mRNA显著增加，但TGF-β1和GM-CSF的mRNA水平与对照有显著差异。使用PK(15)-1512细胞毒性生物测定法检测体外肠道培养上清液中的TNF-α活性，患病样本中的水平显著升高。在任何血清样本中均未检测到TNF-α。对患有不同少菌型疾病形式的绵羊肠道组织进行的进一步分析显示，TNF-α的mRNA显著升高，但其他检测的细胞因子未升高。肠道中促炎细胞因子表达增加，同时伴有免疫反应失败或方向错误，可能有助于副结核病的发病机制以及慢性炎症状态的持续存在。
