Dose-dependent effects of Lactobacillus rhamnosus on serum interleukin-17 production and intestinal T-cell responses in pigs challenged with Escherichia coli
The mechanism underlying the dose effect of probiotics on ameliorating diarrhea has not been fully elucidated.Here, low (1×109 CFU/mL) or high (1×1011 CFU/mL) doses ofLactobacillus rhamnosus ATCC 7469 were administered orally to piglets for 1 week before F4 (K88)-positive enterotoxigenic Escherichia coli (F4+ ETEC) challenge.Administration of a low, but not a high, dose of L.rhamnosus decreased the percentage of CD3+ CD4+ CD8-T cells in the peripheral blood.Notably, transiently increased serum concentrations of interleukin-17A (IL-17A) were observed after F4+ ETEC challenge in pigs pretreated with a high dose of L.rhamnosus.Administration of L.rhamnosus increased the percentage of the small intestinal lamina propria CD3+ CD4+ CD8-cells and Peyer”s patch CD3+ CD4-CD8-and CD3-CD4-CD8+ cells.The percentage of ileal intraepithelial CD3+ CD4-CD8+ cells increased only in the high-dose piglets.Administration of L.rhamnosus downregulated expression of ileal IL-17A after F4+ ETEC challenge but had no effect on expression of gamma interferon (IFN-γ), IL-12, IL-4, and FOXP3 mRNA in the small intestine.Expression of jejunal IL-2, ileal transforming growth factor β1 (TGF-β1), and ileal IL-10 was upregulated in the low-dose piglets after F4+ ETEC challenge.Our findings suggest that amelioration of infectious diarrhea in piglets by L.rhamnosus is associated with the generation of lamina propria CD3+ CD4+ CD8-T cells, the expansion of Peyer”s patch CD3+ CD4-CD8-and CD3-CD4-CD8+ cells, and the attenuation of F4+ ETEC-induced increase in CD3+ CD4+ CD8+ T cells in the small intestine.However, consumption of high doses of L.rhamnosus may increase levels of serum IL-17A after F4+ ETEC challenge, thus eliciting a strong proinflammatory response.
ZHU Yaohong LI Xiaoqiong ZHANG Wei ZHOU Dong LIU Haoyu WANG Jiufeng
College of Veterinary Medicine, China Agricultural University, Beijing 100193, P.R.China Department of Animal Nutrition and Management, Faculty of Veterinary Medicine and Animal Science, Sw
国内会议
中国畜牧兽医学会兽医内科与临床诊疗学分会第八届代表大会暨学术研讨会
大庆
英文
43-58
2015-07-22（万方平台首次上网日期，不代表论文的发表时间）