Diversity of Saccharomyces boulardii CNCM I-745 mechanisms of action against intestinal infections

Figure 7 Effect of Saccharomyces boulardii CNCM I-745 on intestinal mononuclear phagocytes: Dendritic cells expressing CD103 (CD103⁺DC) and macropahge expressing the fractalkine receptor (CX3CR1MΦs). A.CD103⁺DC which expresses the CCR7 on their surface phagocytes the Salmonella (ST) and migrate to the mesenteric lymph nodes (MLN). CX3CR1MΦs which have a high phagocytosis capacity, include bacteria, do not migrate, but remain in the LP where they stimulate T lymphocytes. These MΦs are able to form extensions that pass between the epithelial cells and capture the antigens in the intestinal lumen, among other pathogenic bacteria such as ST. Saccharomyces boulardii CNCM I-745 induces the recruitment of CX3CR1MΦs and promotes phagocytosis of ST by these cells. S. boulardii CNCM I-745 effects the expansion of Ly6C inflammatory monocytes, which are the precursors of CX3CR1 DCs in the bone marrow. In addition, S. boulardii CNCM I-745 reduces the number of ST that migrate to MLN by decreasing the number of migratory DCs. B.In vitro studies have shown that S. boulardii CNCM I-745 can modify lipopolysaccharide activation of migratory DCs. This effect would be due to a molecule of low molecular weight (< 3 kDa) present in S. boulardii CNCM I-745 conditioned medium[64]. Sb: Saccharomyces boulardiiCNCM I-745; ST: Salmonella; MLN: Mesenteric lymph nodes; DCs: Dendritic cells; LPS: Lipopolysaccharide.