The PapG tip adhesin of P fimbriae protects Escherichia coli from neutrophil bactericidal activity.
The PapG tip adhesin of P fimbriae protects Escherichia coli from neutrophil bactericidal activity.
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P 菌毛的 PapG 尖端粘附素可保护大肠杆菌免受中性粒细胞杀菌活性的影响。
DOI：
10.1128/iai.62.12.5296-5304.1994
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发表时间：
1994
影响因子：
3.1
通讯作者：
Abraham,SN
中科院分区：
文献类型：
--
作者：
Tewari,R;Ikeda,T;Malaviya,R;MacGregor,JI;Little,JR;Hultgren,SJ;Abraham,SN
与无菌毛的K-12菌株Escherichia coli ORN 103相比，P-菌毛的E. coliORN 103/pPAP 5与人中性粒细胞的相互作用很弱，并能抵抗中性粒细胞的体外杀菌活性。PapG是位于P菌毛远端的Gal α（1->4）Gal结合部分，它似乎是这种效应的原因，因为一个同基因的PapG突变体，E. coliORN 103/pPAP 24与中性粒细胞的结合作用与无菌毛大肠杆菌相似。coliORN103。虽然没有直接证据，但PapG介导的粘附性差可能与其静电性质有关，因为分离的PapG蛋白的pI为5.2，这表明在生理pH范围内它具有净负电荷。抗PapG抗体克服了PapG的保护作用，并显著增强了P-菌毛E.大肠杆菌与嗜中性粒细胞一起杀死细菌。当一株P-菌毛型临床E.将大肠杆菌菌株或其等基因PapG衍生物注射到小鼠的腹膜腔中，相似数量的中性粒细胞被募集到注射部位。培养2 h后，P-菌毛E.在小鼠腹膜中，在中性粒细胞流入中存活的大肠杆菌生物体的数量大约是存活的PapG-细菌数量的四倍。这一结果表明，PapG蛋白，这是战略性地位于远端区域的P-原纤维结构，保护E。嗜中性粒细胞的杀菌作用。
Compared with Escherichia coli ORN103, a nonfimbriated K-12 strain, P-fimbriated E. coli ORN103/pPAP5 was found to interact poorly with human neutrophils and resist their bactericidal activity in vitro. PapG, the Gal alpha(1-->4)Gal binding moiety located at the distal end of the P fimbrial filament, appeared to be responsible for this effect because an isogenic PapG- mutant, E. coli ORN103/pPAP24, exhibited binding interactions with neutrophils that were similar to nonfimbriated E. coli ORN103. Although no direct evidence is available, the poor adherence mediated by PapG could be related to its electrostatic properties because the isolated PapG protein had a pI of 5.2, which indicated that in the physiological pH range it possessed a net negative charge. Antibodies against PapG overcame the protective effect of PapG and markedly enhanced the interactions of P-fimbriated E. coli with neutrophils resulting in bacterial killing. When a P-fimbriated clinical E. coli strain or its isogenic PapG- derivative was injected into the peritoneal cavities of mice, a similar number of neutrophils was recruited to the site of injection. After 2 h, the number of P-fimbriated E. coli organisms that survived the neutrophil influx in the mouse peritoneum was approximately four times more than the number of surviving PapG- bacteria. This result demonstrates that the PapG protein, which is strategically located at the distal region of the P-fibrillum structure, protects E. coli from the bactericidal action of neutrophils.