Evidence for Horizontal Gene Transfer of Two Antigenically Distinct O Antigens in Bordetella bronchiseptica
Evidence for Horizontal Gene Transfer of Two Antigenically Distinct O Antigens in Bordetella bronchiseptica
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DOI：
10.1128/iai.01448-08
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发表时间：
2009-08-01
影响因子：
3.1
通讯作者：
Harvill, Eric T.
中科院分区：
文献类型：
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作者：
Buboltz, Anne M.;Nicholson, Tracy L.;Harvill, Eric T.
宿主免疫是抗原多样性的主要驱动力，导致病原体可以逃避密切相关菌株诱导的免疫。在这里，我们显示了两个支气管败血波尔德氏菌株，RB50和1289，分别表达两个抗原性不同的O-抗原血清型(分别为O1和O2)。当对另外18株支气管败血杆菌进行血清学分型时，发现所有菌株都表达O1或O2血清型。比较基因组杂交和聚合酶链式反应筛选表明，O1或O2血清型的表达分别与含有经典或替代O-抗原基因的菌株相关。对49株支气管败血杆菌进行多位点序列分型分析，构建了系统发育树，发现这两个O-抗原基因座并不与某一特定的谱系相关联，证明这两个基因座在支气管败血杆菌之间是水平转移的。用纯化的RB50(O1)、1289(O2)或RB50 Delta WBM(O抗原缺失)菌株的脂多糖免疫小鼠的实验表明，这些O抗原在体内不具有交叉保护作用。O-抗原血清型之间缺乏交叉免疫似乎是导致抗体介导的菌株间清除效率低下的原因之一。总之，这些数据与支气管败血杆菌的O抗原基因座在菌株之间水平转移并编码不同的抗原血清型，导致低效交叉免疫的想法是一致的。
Host immunity is a major driving force of antigenic diversity, resulting in pathogens that can evade immunity induced by closely related strains. Here we show that two Bordetella bronchiseptica strains, RB50 and 1289, express two antigenically distinct O-antigen serotypes (O1 and O2, respectively). When 18 additional B. bronchiseptica strains were serotyped, all were found to express either the O1 or O2 serotype. Comparative genomic hybridization and PCR screening showed that the expression of either the O1 or O2 serotype correlated with the strain containing either the classical or alternative O-antigen locus, respectively. Multilocus sequence typing analysis of 49 B. bronchiseptica strains was used to build a phylogenetic tree, which revealed that the two O-antigen loci did not associate with a particular lineage, evidence that these loci are horizontally transferred between B. bronchiseptica strains. From experiments using mice vaccinated with purified lipopolysaccharide from strain RB50 (O1), 1289 (O2), or RB50 Delta wbm (O antigen deficient), our data indicate that these O antigens do not confer cross-protection in vivo. The lack of cross-immunity between O-antigen serotypes appears to contribute to inefficient antibody-mediated clearance between strains. Together, these data are consistent with the idea that the O-antigen loci of B. bronchiseptica are horizontally transferred between strains and encode antigenically distinct serotypes, resulting in inefficient cross-immunity.