This investigation was performed to assess the supplementation of probiotics on cytokine expression and lymphocyte subpopulation in Campylobacter coli challenged chickens. Thirty-six individuals were equally separated into four experimental treatments: C = untreated chickens, LB = probiotic control (Lactobacillus fermentum), Cc = Campylobacter-challenged control, LBCc = probiotic + Cc. All chicks were slaughtered and cecum samples were collected on day 4 postinfection. Gene expression analysis, using reverse transcription quantitative PCR (RT-qPCR), revealed significant differences in cytokine transcript expression between untreated and probiotic-treated chickens. In addition, flow cytometry was used to quantitate the levels of lymphocyte subpopulations. Principal component analysis showed that probiotic administration induced an overall downregulation of cytokine expression. C. coli exposure provoked a similar response to that of L. fermentum but to a lesser extent. Colonization of C. coli in the presence of the probiotic evoked a complex response with an upregulation of some type II cytokines, including interleukin IL-4 and IL-13, which could explain the increased presence of antibodies in both lamina propria and epithelium. Moreover, despite that the percentage of CD8 intraepithelial lymphocytes (IELs) was found to be higher, downregulation of proinflammatory cytokines IL-15, IL-16, and interferon γ was observed. This suggests that the detected CD8 are not effector cells but induced IELs, which release antimicrobial peptides, and are ready to be primed upon encountering antigen. These outcomes demonstrate that probiotic administration promotes a humoral response to a C. coli infection while dampening any potential inflammation mediated by effector T cells in 1-week-old chicks.

中文翻译：

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发酵乳杆菌给药可调节感染弯曲杆菌的肉鸡的细胞因子表达和淋巴细胞亚群水平。

进行这项研究是为了评估益生菌对感染弯曲杆菌的鸡中细胞因子表达和淋巴细胞亚群的影响。36 个人被平均分成四个实验处理：C = 未处理的鸡，LB = 益生菌对照（发酵乳杆菌），Cc = 弯曲杆菌- 挑战对照，LBCc = 益生菌 + Cc。在感染后第 4 天屠宰所有小鸡并收集盲肠样品。使用逆转录定量 PCR (RT-qPCR) 进行的基因表达分析揭示了未处理和益生菌处理的鸡之间细胞因子转录表达的显着差异。此外，流式细胞术用于定量淋巴细胞亚群的水平。主成分分析显示益生菌给药诱导细胞因子表达的整体下调。大肠杆菌暴露引起了与发酵乳杆菌相似的反应，但程度较轻。大肠杆菌的定植在益生菌存在的情况下引起复杂的反应，一些 II 型细胞因子上调，包括白细胞介素 IL-4 和 IL-13，这可以解释固有层和上皮中抗体的存在增加。此外，尽管发现 CD8 上皮内淋巴细胞 (IEL) 的百分比较高，但观察到促炎细胞因子 IL-15、IL-16 和干扰素 γ 的下调。这表明检测到的 CD8 不是效应细胞，而是诱导 IEL，它们释放抗菌肽，并准备好在遇到抗原时被激发。这些结果表明，益生菌的施用促进了对大肠杆菌感染的体液反应，同时抑制了 1 周龄雏鸡中由效应 T 细胞介导的任何潜在炎症。