幽门螺杆菌脂多糖的抗原变异

Antigenic variation in Helicobacter pylori lipopolysaccharide.

目的：研究幽门螺杆菌（Ｈｅｌｉｃｏｂａｃｔｅｒｐｙｌｏｒｉ，Ｈｐ）标准菌株ＮＣＴＣ１１６３７的脂多糖（Ｌｉｐｏｐｏｌｙｓａｃｈａｒｉｄｅ，ＬＰＳ）的抗原变异。方法：利用血清学标定及菌溶免疫印迹研究ＨｐＬＰＳ的抗原变异，并用聚丙烯酰胺凝胶电泳及免疫印迹以鉴定ＮＣＴＣ１１６３７及变异株的性质。结果：Ｈｐ的ＬＰＳ表现出０２％～０．５％的抗原变异从而产生几种不同的ＬＰＳ变异株。其一种抗原变异是ＮＣＴＣ１１６３７失去了α１，３－岩藻糖变为表达ｉ抗原的变异株Ｋ４１，而不再表达ＬｅｗｉｓＸ（ＬｅＸ），这种由Ｌｅｘ到ｉ抗原的变异是可逆性的；第二种变异是由于获得了α１，２－岩藻糖从而表达Ｌｅｘ和Ｌｅｙ（ＩＣ）；第三种抗原变异是由于失去了多聚主链从而导致变异株（１ｂ）表达单体Ｌｅｙ。结论：Ｈｐ的标准株的ＬＰＳ表现出抗原变异。

Aims: To investigate the antigenic variation in Helicobacter pylori(Hp) type strain (NCTC 11637) lipopolysaccharide (LPS). Methods: Serotyping and colony blot were used to investigate the antigenic variation in Hp LPS.The characterization of NCTC 11637 and its variants was checked by using the methods of SDS-polyacrylamids gel(SDS-PAGE) and Western blot.Resulits: Hp LPS display a high fraquency (0.2% to 0.5%) of antigenic variation,resulting in the presence of several LPS variants in one bacterial cell population,One type of antigenic variation implied the loss of α1,3 -linked fucose,resulting in variants that expressed the i antigen.The switch of LeX (NCTC 11637) to i antigen (K4.1) was reversible;A second group of variants (1c) arose by acquisition of α1,2 -linked fucose which hence expressed LeX plus LeY;A third proup of variants (1b) arose by loss of polymeric main chain which resulted in expression of monomeric LeY.Conclusions: Hp type strain LPS displays antigenic variation,which may incress the heterogeneity of H.pylori.