Prohl Annette, Ostermann Carola H, Rummel Christoph D, Roth Joachim, Reinhold Petra
Institute of Molecular Pathogenesis at 'Friedrich-Loeffler-Institut' (Federal Research Institute for Animal Health), Jena, Germany.
Institute of Veterinary Physiology and Biochemistry, Justus-Liebig-University Giessen, Germany.
PLoS One. 2017 Dec 27;12(12):e0189321. doi: 10.1371/journal.pone.0189321. eCollection 2017.
In rodent models of experimentally induced fever, the important role of interleukin-6 (IL-6) as a circulating endogenous pyrogen is well established. Studies employing larger animal species and real infections are scarce. Therefore, we assessed bioactive IL-6 in peripheral blood and in broncho-alveolar lavage fluid (BALF) of calves after intra-bronchial inoculation with vital Chlamydia psittaci (Cp), with inactivated Cp, or with BGM cells. Only calves inoculated with vital Cp developed fever (peak at 2-3 days after challenge) and significantly increased IL-6 activity. Controls inoculated with either inactivated Cp or BGM cells also expressed increased bioactive IL-6, but no fever developed. Activity of IL-6 in BALF was significantly higher compared to blood serum. This experimental model of Cp infection revealed no apparent relation between IL-6 in blood and body temperature, but did reveal a relation between IL-6 and other markers of inflammation in BALF. We conclude that a local inflammatory response in the lungs of infected calves caused fever, which developed by mechanisms including other mediators besides IL-6.
在实验性诱导发热的啮齿动物模型中，白细胞介素-6（IL-6）作为一种循环内源性致热原的重要作用已得到充分证实。采用大型动物物种和实际感染的研究很少。因此，我们评估了支气管内接种活鹦鹉热衣原体（Cp）、灭活Cp或BGM细胞后，犊牛外周血和支气管肺泡灌洗液（BALF）中的生物活性IL-6。只有接种活Cp的犊牛出现发热（攻击后2-3天达到峰值）且IL-6活性显著增加。接种灭活Cp或BGM细胞的对照组也表现出生物活性IL-6增加，但未出现发热。BALF中IL-6的活性明显高于血清。这种Cp感染实验模型显示血液中的IL-6与体温之间没有明显关系，但确实揭示了BALF中IL-6与其他炎症标志物之间的关系。我们得出结论，感染犊牛肺部的局部炎症反应导致了发热，其发生机制包括IL-6以外的其他介质。
