Phosphocholine （PC） is the immunodominant epitope found on the surface of a number of microorganisms, including Streptococcus pneumoniae （SPn）, and is thought to play a vital role in the pathogenesis of SPn. B cel...Phosphocholine （PC） is the immunodominant epitope found on the surface of a number of microorganisms, including Streptococcus pneumoniae （SPn）, and is thought to play a vital role in the pathogenesis of SPn. B cells expressing M 167Hκ24L immunoglobulin receptors specific for PC have been shown to be autoreactive in that they undergo clonal deletion in both X-linked immune-deficient and Rag-/- mice. We have now shown that B cells expressing M603HK8L PC-specific receptors also delete in Rag-/- mice, whereas those expressing T15HK22L transgenes do not delete. However, T15HK22L B cells are lost in normal heterozygous transgenic mice because they cannot compete with normal B cells. These data indicate that M167Hκ24L and M603H^8L PC-specific B cells are recognizing an autoantigen expressed on membranes which causes them to downregulate their receptors and clonally delete, while T15Hκ22L B cells are tolerized by a soluble form of PC-antigen which results in their being trapped in the spleen. Thus, the types of tolerance seen in autoreactive PC-specific B cells are dependent on the idiotype of the receptors expressed.展开更多
肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidin...肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidine 5'-diphosphocholine,COD-胆碱)和磷脂酰乙醇胺甲基化途径参与了PC的生物合成。文中就PC的合成和转运对VLDL分泌功能的影响进行综述。展开更多
文摘Phosphocholine （PC） is the immunodominant epitope found on the surface of a number of microorganisms, including Streptococcus pneumoniae （SPn）, and is thought to play a vital role in the pathogenesis of SPn. B cells expressing M 167Hκ24L immunoglobulin receptors specific for PC have been shown to be autoreactive in that they undergo clonal deletion in both X-linked immune-deficient and Rag-/- mice. We have now shown that B cells expressing M603HK8L PC-specific receptors also delete in Rag-/- mice, whereas those expressing T15HK22L transgenes do not delete. However, T15HK22L B cells are lost in normal heterozygous transgenic mice because they cannot compete with normal B cells. These data indicate that M167Hκ24L and M603H^8L PC-specific B cells are recognizing an autoantigen expressed on membranes which causes them to downregulate their receptors and clonally delete, while T15Hκ22L B cells are tolerized by a soluble form of PC-antigen which results in their being trapped in the spleen. Thus, the types of tolerance seen in autoreactive PC-specific B cells are dependent on the idiotype of the receptors expressed.
文摘肝为脂蛋白的合成和分泌提供磷脂酰胆碱(phosphatidylcholine,PC),但同时又接受来自血浆脂蛋白中的PC。肝极低密度脂蛋白(very low density lipoprotein,VLDL)的分泌需要PC的生物合成,最近的研究显示5'-胞苷二磷酸-胆碱途径(cytidine 5'-diphosphocholine,COD-胆碱)和磷脂酰乙醇胺甲基化途径参与了PC的生物合成。文中就PC的合成和转运对VLDL分泌功能的影响进行综述。
