The regulation of peripheral immune system development by gut microbiota discovered by Yan Shi group
Source：Yan Shi
2016-03-21
Dr Yan Shi and colleagues from School of medicine, Tsinghua University, have reported that a wave of CD45+CD11b+CD103+RALDH+ dendritic cells, driven by commensal fungi, migrates to the peripheral lymph nodes after birth and promotes lymph node maturation. These results entitled with “Peripheral Lymphoid Volume Expansion and Maintenance Are Controlled by GutMicrobiota via RALDH+ Dendritic Cells” were published in Immunity of February 16th 2016.
The emerging role of commensal microbiota on immune system development is increasingly being recognized. Germ-free mice show clear developmental defects in secondary lymphoid organs after birth. How the microbiota contributes to these changes remains unknown. The authors found that a population of CD11c+CD11b+CD103+RALDH+ (neonatal migratory or neo-mi) DCs in neonatal peripheral lymph nodes, which had never reported in the existing literature. Isolated from SPF mice, these cells promoted peripheral lymph node development when iv injected into germ-free mice. Depletion of bacteria and fungi in the mouse intestine showed that neo-mi DCs migrated out of lamina properia in response to fungi. When these RALDH expressing cells were blocked with DEAB, the lymph nodes development was inhibited. After the arrival of these cells, high endothelial venules started theaddressin profile conversion from MAdCAM-1dominated neonatal pattern to PNAd-dominated adult pattern. Interestingly, these retinoic acid producing cells imprinted lymphocytes transiting through those lymph nodes for gut homing ability by up-regulate α4β7 and CCR9 chemotactic receptors through retinoic acid signaling. Hence, lymphocytes were redirected to the gut in the early weeks after birth. A small number of neo-mi DCs were also presented in the adult mice peripheral lymph nodes. Vitamin A deficient mice suffer from lymph node structure attrition and cellularityloss due to the absence of this small population of DCs. Therefore, this finding indicates that the presence of these cells is essential for the adult lymph nodes structure maintenance. These outcomes contribute to enhance our understanding of commensal fungi in regulating immune system development.
Article: Zhang, Z., Li, J., Zheng, W., Zhao, G., Zhang, H., Wang, X., … Shi, Y. (2016). Peripheral Lymphoid Volume Expansion and Maintenance Are Controlled by Gut Microbiota via RALDH+ Dendritic Cells. Immunity, 44(2), 330–342.
http://doi.org/10.1016/j.immuni.2016.01.004
The emerging role of commensal microbiota on immune system development is increasingly being recognized. Germ-free mice show clear developmental defects in secondary lymphoid organs after birth. How the microbiota contributes to these changes remains unknown. The authors found that a population of CD11c+CD11b+CD103+RALDH+ (neonatal migratory or neo-mi) DCs in neonatal peripheral lymph nodes, which had never reported in the existing literature. Isolated from SPF mice, these cells promoted peripheral lymph node development when iv injected into germ-free mice. Depletion of bacteria and fungi in the mouse intestine showed that neo-mi DCs migrated out of lamina properia in response to fungi. When these RALDH expressing cells were blocked with DEAB, the lymph nodes development was inhibited. After the arrival of these cells, high endothelial venules started theaddressin profile conversion from MAdCAM-1dominated neonatal pattern to PNAd-dominated adult pattern. Interestingly, these retinoic acid producing cells imprinted lymphocytes transiting through those lymph nodes for gut homing ability by up-regulate α4β7 and CCR9 chemotactic receptors through retinoic acid signaling. Hence, lymphocytes were redirected to the gut in the early weeks after birth. A small number of neo-mi DCs were also presented in the adult mice peripheral lymph nodes. Vitamin A deficient mice suffer from lymph node structure attrition and cellularityloss due to the absence of this small population of DCs. Therefore, this finding indicates that the presence of these cells is essential for the adult lymph nodes structure maintenance. These outcomes contribute to enhance our understanding of commensal fungi in regulating immune system development.
Article: Zhang, Z., Li, J., Zheng, W., Zhao, G., Zhang, H., Wang, X., … Shi, Y. (2016). Peripheral Lymphoid Volume Expansion and Maintenance Are Controlled by Gut Microbiota via RALDH+ Dendritic Cells. Immunity, 44(2), 330–342.
http://doi.org/10.1016/j.immuni.2016.01.004
