Study on the formation and function of exosomes

外泌体由蛋白质和脂质组成，它们是由包括感染细菌的细胞在内的细胞分泌的。为了检测脂质A部分的结构，我们开发了一种质谱分析脂质A的方法。我们发现2,5 -二羟基苯甲酸基质更适合检测氨基阿拉伯糖修饰。鼠伤寒沙门氏菌LpxR可能通过3'- o -去酰化解毒脂质A；然而，去酰化在其适应宿主细胞中的作用尚不清楚。细胞内复制实验表明，lpxR-null菌株的生长低于野生型菌株，表明脂质a3 '- o -去酰化有利于细胞内生长。

Exosomes are composed of proteins and lipids, which are secreted from cells including those infected with bacteria. In order to examine the structure of lipid A portion of LPS, which is potentially involved in the exosomes, we developed a method for mass spectrometry analysis of lipid A. We found that 2, 5-dihydroxybenzoic acid matrix was preferable for the detection of aminoarabinose modification. Salmonella Typhimurium LpxR potentially detoxifies lipid A by 3'-O-deacylation ; however, the involvement of deacylation in its adaptation to host cells remains unclear. Intracellular replication assay demonstrated that growth of the lpxR-null strain was lower than that of the wild-type strain, indicating that lipid A 3'-O-deacylation is beneficial for intracellular growth.