Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 16 2 2017 05 07 147 158 EN Ai-Li Li Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Yi-qio Sun Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Peng Du Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Xiang-Chen Meng Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Ling Guo Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Shuang Li Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China Chao Zhang Key laboratory of Dairy Science, Ministry of Education, College of Food Sciences, Northeast Agriculture University, Xiangfang District, Harbin, Heilongjiang, China 2015 12 01 2016 02 07 Our previous study reported that Lactobacillus acidophilus(L.acidophilus)  key laboratory of dairy science  (KLDS) 1.0738 had an effective impact on inhibiting β-lactoglobulin (β-lg) allergy. This study further investigated the anti-allergic activity of peptidoglycan (PGN) isolated from KLDS 1.0738. This study aimed to assess whether toll-like receptor 2 (TLR2)/NF-kappaB (NF-κB) signaling activated by PGN was responsible for reducing allergic inflammation.  Our data showed that administration of  L. acidophilus PGN inhibited IgE production and improved the Treg/Th17 balance toward a Treg response in a mouse model of β-lg allergy. In addition, treating different doses L. acidophilus PGN to sensitized mice significantly increased TLR2 levels, along with enhancing NF-κB expression, especially in medium and high concentration (p<0.05). Further analysis revealed that the mRNA expression of TLR2 and NF-κB were positively correlated with the Foxp3 mRNA expression (p<0.05), but were negatively correlated with the RORγt mRNA expression in L. acidophilus PGN-treated group compared to allergy group (p<0.05). This study suggests PGN was similar to probiotics in preventing β-lg allergy through regulating Treg/Th17 imbalance, and activation of TLR2/NF-κB signaling may be involved in this process. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/712 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/712/731