Induction of chicken cytokine responses in vivo and in vitro by lipooligosaccharide of Campylobacter jejuni HS:10

Campylobacter jejuni is a pathogen of the gastrointestinal tract of humans, but colonizes chickens for prolonged periods without causing disease. It is unclear what host and bacterial mechanisms maintain a non-inflammatory state in chickens. The present work was undertaken to characterize cytokine responses of chickens to purified lipooligosaccharide (LOS) of C jejuni HS:10. Chickens were injected with purified LOS, and expression of interleukin (IL)-1 beta (pro-inflammatory cytokine), IL-8 (pro-inflammatory chemokine), interferon (IFN)gamma (Th1-like cytokine), IL-10 (immune regulatory/anti-inflammatory cytokine) and IL-13 (Th2-like cytokine) was evaluated in spleen using quantitative RT-PCR, up to 24h post-injection. In an in vitro study, splenocytes were incubated with LOS, and cytokine expression followed up to 18 h. Chickens injected with LOS had increased expression of IL-1 beta up to 24 h later. Expression of IL-8 was significantly increased at 2 h but then declined below baseline. Expression of IFN gamma, and IL-10 was increased significantly at 2 h, but declined thereafter. Splenocytes incubated with LOS had increased expression of IL-1 beta and IL-8 up to 18 h of incubation. Expression of IFN gamma was increased at 6 and 18 h, IL-10 was increased at 2 h, but expression of IL-13 did not differ significantly up to 18 h. It is concluded that LOS of C jejuni can induce expression of pro-inflammatory IL-1 beta and IL-8, as well as IF gamma and IL-10 in chickens. More extensive studies with more prolonged exposure to LOS are needed to further clarify the interaction between C jejuni and the chicken host. (C) 2013 Elsevier B.V. All rights reserved.