Soong C J, Kain K C, Abd-Alla M, Jackson T F, Ravdin J I
Department of Medicine, Case Western Reserve University, Cleveland, Ohio.
J Infect Dis. 1995 Mar;171(3):645-51. doi: 10.1093/infdis/171.3.645.
The 170-kDa subunit of the galactose-inhibitable adherence lectin of Entamoeba histolytica mediates attachment to colonic mucins and host cells. The DNA fragment encoding the 170-kDa subunit was produced by polymerase chain reaction (PCR) and divided into four sections by restriction endonucleases. The third section (designated LC3, base pairs 2273-3397) encodes a cysteine-rich fusion protein that was recognized by adherence-inhibitory anti-lectin monoclonal antibodies and serum antibodies from 95% of subjects with amebic liver abscess. Immunization of gerbils with purified recombinant LC3-encoded protein (10 micrograms) with Titermax adjuvant elicited a high-titer serum anti-LC3 IgG antibody response and protective immunity against intrahepatic challenge with 0.5 x 10(6) virulent axenic trophozoites (strain HM1:IMSS; 71% vaccine efficacy, P < .01). In summary, a recombinant cysteine-rich portion of the 170-kDa lectin subunit was highly antigenic, immunogenic, and effective as a subunit vaccine in an experimental animal model of amebic liver abscess.
溶组织内阿米巴半乳糖抑制性黏附凝集素的170-kDa亚基介导其与结肠黏蛋白和宿主细胞的黏附。通过聚合酶链反应（PCR）产生编码170-kDa亚基的DNA片段，并用限制性内切酶将其分为四个部分。第三部分（命名为LC3，碱基对2273 - 3397）编码一种富含半胱氨酸的融合蛋白，该蛋白可被黏附抑制性抗凝集素单克隆抗体以及95%的阿米巴肝脓肿患者的血清抗体识别。用含Titermax佐剂的纯化重组LC3编码蛋白（10微克）免疫沙鼠，可引发高滴度血清抗LC3 IgG抗体反应，并对0.5×10⁶ 毒力纯培养滋养体（菌株HM1:IMSS）的肝内攻击产生保护性免疫（疫苗效力71%，P <.01）。总之，170-kDa凝集素亚基的重组富含半胱氨酸部分具有高度抗原性、免疫原性，并且在阿米巴肝脓肿实验动物模型中作为亚单位疫苗是有效的。
