Department of Medicine, New York University School of Medicine and Veteran's Administration Medical Center, New York, NY 10016, USA.
J Exp Med. 2009 Dec 21;206(13):3061-72. doi: 10.1084/jem.20090683. Epub 2009 Dec 14.
Variation of surface antigen expression is a mechanism used by microbes to adapt to and persist within their host habitats. Helicobacter pylori, a persistent bacterial colonizer of the human stomach, can alter its surface Lewis (Le) antigen expression. We examined H. pylori colonization in mice to test the hypothesis that host phenotype selects for H. pylori (Le) phenotypes. When wild-type and Le(b)-expressing transgenic FVB/N mice were challenged with H. pylori strain HP1, expressing Le(x) and Le(y), we found that bacterial populations recovered after 8 mo from Le(b)-transgenic, but not wild-type, mice expressed Le(b). Changes in Le phenotype were linked to variation of a putative galactosyltransferase gene (beta-(1,3)galT); mutagenesis and complementation revealed its essential role in type I antigen expression. These studies indicate that H. pylori evolves to resemble the host's gastric Le phenotype, and reveal a bacterial genetic locus that is subject to host-driven selection pressure.
表面抗原表达的变异是微生物适应和在宿主栖息地中生存的一种机制。幽门螺杆菌是一种持久定植于人类胃部的细菌，它可以改变其表面路易斯（Le）抗原的表达。我们研究了幽门螺杆菌在小鼠中的定植，以检验宿主表型选择幽门螺杆菌（Le）表型的假说。当野生型和表达 Le(b)的转基因 FVB/N 小鼠受到表达 Le(x)和 Le(y)的幽门螺杆菌菌株 HP1 的挑战时，我们发现，从 Le(b)-转基因而不是野生型小鼠中恢复的细菌种群表达 Le(b)。Le 表型的变化与一种假定的半乳糖基转移酶基因（β-(1,3)galT）的变异有关；突变和互补实验揭示了它在 I 型抗原表达中的重要作用。这些研究表明，幽门螺杆菌进化为类似于宿主胃中的 Le 表型，并揭示了一个受宿主驱动的选择压力的细菌遗传基因座。
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