The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, Midlothian, EH25 9RG, UK.
Scotland's Rural College, West Main Road, Edinburgh, EH9 3JG, UK.
Vet Res. 2018 Jan 9;49(1):3. doi: 10.1186/s13567-017-0501-y.
Campylobacter jejuni is the leading cause of bacterial food-borne gastroenteritis worldwide and human infections are frequently associated with handling and consumption of contaminated poultry. The polysaccharide capsule of C. jejuni plays important roles in colonisation of the chicken gut, invasion of epithelial cells and serum resistance and is subject to modification with O-methyl phosphoramidate (MeOPN) in most strains. In this study, the cytokine responses of mouse bone marrow-derived macrophages (mBMMs), chicken bone marrow-derived macrophages (chBMMs) and human monocyte-derived macrophages (hMDMs) were measured following infection with C. jejuni 11168H wild-type (WT) or isogenic mutants lacking either the capsule (Δcj1439) or its MeOPN modification (Δcj1417). Consistent with previous observations using murine bone marrow-derived dendritic cells, mutants lacking the capsule or MeOPN elicited enhanced transcription of IL-6 and IL-10 in mBMMs compared to wild-type C. jejuni. However, the lack of capsule and MeOPN did not alter IL-6 and IL-10 expression in chBMMs and hMDMs compared to C. jejuni WT. Phagocytosis assays showed the acapsular mutant was not impaired in uptake or net intracellular survival after phagocytosis in both chicken and human macrophages; however, the phagocytosis of the MeOPN mutant was significantly decreased in both chicken and human macrophages. In conclusion, differences in the response of macrophages of varying host origin to Campylobacter were detected. The absence of MeOPN modification on the capsule of C. jejuni did not alter the levels of innate cytokine expression in both chicken and human macrophages compared to the 11168H WT, but affected phagocytosis by host macrophages.
空肠弯曲菌是全球细菌性食源性胃肠炎的主要致病菌，人类感染常与接触和食用受污染的家禽有关。空肠弯曲菌的多糖荚膜在鸡肠道定植、侵袭上皮细胞和血清抗性方面发挥着重要作用，并且在大多数菌株中会受到 O-甲基磷酰胺（MeOPN）的修饰。在这项研究中，通过感染空肠弯曲菌 11168H 野生型（WT）或缺乏荚膜（Δcj1439）或其 MeOPN 修饰（Δcj1417）的同基因突变体，测量了小鼠骨髓来源的巨噬细胞（mBMMs）、鸡骨髓来源的巨噬细胞（chBMMs）和人单核细胞来源的巨噬细胞（hMDMs）的细胞因子反应。与使用鼠骨髓来源树突状细胞的先前观察结果一致，与野生型空肠弯曲菌相比，缺乏荚膜或 MeOPN 的突变体在 mBMMs 中引发了 IL-6 和 IL-10 的转录增强。然而，与空肠弯曲菌 WT 相比，缺乏荚膜和 MeOPN 并没有改变 chBMMs 和 hMDMs 中的 IL-6 和 IL-10 表达。吞噬作用测定表明，在鸡和人巨噬细胞中，无荚膜突变体在吞噬作用后摄取或净细胞内存活均不受影响；然而，MeOPN 突变体的吞噬作用在鸡和人巨噬细胞中均显著降低。总之，检测到不同宿主来源的巨噬细胞对空肠弯曲菌反应的差异。与 11168H WT 相比，空肠弯曲菌荚膜上 MeOPN 修饰的缺失并未改变鸡和人巨噬细胞中固有细胞因子表达的水平，但影响了宿主巨噬细胞的吞噬作用。
