Open AccessCirculating and broncho-alveolar interleukin-6 in relation to body temperature in an experimental model of bovine Chlamydia psittaci infection
Author(s) -
Annette Prohl,
Carola Ostermann,
Christoph Rummel,
Joachim Roth,
Petra Reinhold
Publication year - 2017
Publication title -
plos one
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.99
H-Index - 332
ISSN - 1932-6203
DOI - 10.1371/journal.pone.0189321
Subject(s) - chlamydia psittaci , immunology , inflammation , interleukin , biology , inoculation , peripheral blood , interleukin 6 , chlamydia , medicine , cytokine
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.