Role of receptor binding in toxicity, immunogenicity, and adjuvanticity of Escherichia coli heat-labile enterotoxin
Role of receptor binding in toxicity, immunogenicity, and adjuvanticity of Escherichia coli heat-labile enterotoxin
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DOI：
10.1128/iai.65.12.4943-4950.1997
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发表时间：
1997-12-01
影响因子：
3.1
通讯作者：
Clements, JD
中科院分区：
文献类型：
--
作者：
Guidry, JJ;Cardenas, L;Clements, JD
通过比较天然大肠杆菌（LT）和LT（G33 D）（一种E亚单位受体结合突变体）与半乳糖和GR II结合的能力、对小鼠Y-1肾上腺肿瘤细胞的毒性、刺激Caco-2细胞中腺苷酸环化酶的能力、在专利小鼠模型中的肠毒性，以及口服免疫原性和佐剂性。与天然LT相比，LT（G33 D）不能结合Sepharose 4 B或GM 1的半乳糖基部分，但保留了凝集素样结合6%琼脂糖珠上固定的半乳糖的能力。LT（G33 D）在专利小鼠模型中没有肠毒性，但对小鼠Y-1肾上腺肿瘤细胞显示出残留毒性，并且具有与天然LT相当的刺激Caco-2细胞中腺苷酸环化酶的能力（5，000 pmol/mg蛋白质vs 6，900 pmol/mg蛋白质）。此外，LT（G33 D）不能作为有效的口服佐剂诱导针对共同施用抗原的免疫球蛋白G或A。此外，LT（G33 D）引起针对自身的可忽略的血清和粘膜抗体应答。这些数据表明LT的毒性、免疫原性和口服佐剂性依赖于B亚基与神经节苷脂GM 1的结合。
The role of receptor binding in the toxicity, immunogenicity, and adjuvanticity of the heat-labile enterotoxin of Escherichia coli (LT) was examined by comparing native LT and LT(G33D), a E-subunit receptor binding mutant, with respect to the ability to bind to galactose and to GR II, toxicity on mouse Y-1 adrenal tumor cells, the ability to stimulate adenylate cyclase in Caco-2 cells, enterotoxicity in the patent mouse model, and oral immunogenicity and adjuvanticity. In contrast to native LT, LT(G33D) was unable to bind to the galactosyl moiety of Sepharose 4B or GM1 but did retain the lectin-like ability to bind to immobilized galactose on 6% agarose beads. LT(G33D) had no enterotoxicity in the patent mouse model but exhibited residual toxicity on mouse Y-1 adrenal tumor cells and had an ability equivalent to that of native LT to stimulate adenylate cyclase in Caco-2 cells (5,000 versus 6,900 pmol per mg of protein). In addition, LT(G33D) was unable to serve as an effective oral adjuvant for induction of immunoglobulin G or A directed against a coadministered antigen, Furthermore, LT(G33D) elicited negligible serum and mucosal antibody responses against itself. These data indicate that the toxicity, immunogenicity, and oral adjuvanticity of LT are dependent upon binding of the B subunit to ganglioside GM1.