乳酸片球菌K15可通过激活IgA产生分子机制来增加唾液中的IgA浓度

Title：
The molecular mechanism for activating IgA production by Pediococcus acidilactici K15 and the clinical impact in a randomized trial

DOI：
10.1038/s41598-018-23404-4

Abstract：
IgA secretion at mucosal sites is important for host defence against pathogens as well as maintaining the symbiosis with microorganisms present in the small intestine that affect IgA production. In the present study, we tested the ability of 5 strains of lactic acid bacteria stimulating IgA production, being Pediococcus acidilactici K15 selected as the most effective on inducing this protective immunoglobulin. We found that this response was mainly induced via IL-10, as efficiently as IL-6, secreted by K15-stimulated dendritic cells. Furthermore, bacterial RNA was largely responsible for the induction of these cytokines; double-stranded RNA was a major causative molecule for IL-6 production whereas single-stranded RNA was critical factor for IL-10 production. In a randomized, double-blind, placebo-controlled clinical trial, ingestion of K15 significantly increased the secretory IgA (sIgA) concentration in saliva compared with the basal level observed before this intervention. These results indicate that functional lactic acid bacteria induce IL-6 and IL-10 production by dendritic cells, which contribute to upregulating the sIgA concentration at mucosal sites in humans.

All Authors：
Tadaomi Kawashima,Naho Ikari, Tomoko Kouchi, Yasuyuki Kowatari, Yoshiro Kubota, Naoki Shimojo & Noriko M Tsuji

First Authors：
Tadaomi Kawashima

Correspondence：
Tadaomi Kawashima

摘要：

      黏膜部位IgA的分泌对宿主抵抗病原体和维持肠道菌群共生非常重要；细胞实验表明，乳酸片球菌K15诱导B细胞分泌IgA的能力最强；其主要机制为：K15分别通过双链RNA及单链RNA刺激树突细胞分泌IL-6和IL-10，从而刺激B细胞分泌IgA； 在一项随机、双盲、安慰剂对照临床试验中，补充K15可显著增加受试者唾液中IgA浓度，主要是功能性乳酸菌通过诱导树突细胞产生IL-6和IL-10，从而增加人类黏膜部位sIgA浓度。