单克隆抗体鉴别溶组织内阿米巴的致病性

MONOCLONAL ANTIBODY IDENTIFICATION OF PATHOGENIC ENTAMOEBA HISTOLYTICA

用由溶组织内阿米巴致病株（ＨＭ－１：ＩＭＳＳ）为免疫原诱导产生的特异性单克隆抗体（ＭｃＡｂ）４Ｇ６，与从急性阿米巴痢疾患者或包囊携带者分离的溶组织内阿米巴（Ｅｈ）滋养体进行间接荧光抗体反应和淀粉凝胶电泳同工酶分析。显示，从有发热、腹泻、脓血便患者体内分离的虫株与ＭｃＡｂ４Ｇ６出现阳性反应，滴度达１：５１２０；同工酶分析也属于致病性酶株群Ⅱ。而有发热、腹泻、无脓血便患者体内分离的虫体与ＭｃＡｂ４Ｇ６均为阴性反应，且为非致病性酶株群Ⅰ。提示，致病性虫株与非致病性虫株的免疫原性不同，应用本法可准确鉴别致病性虫株，且简便、价廉、快速，还可用于流行病学调查。

A monoclonal antibody,4G6, was produced against trophozoites of Entamoeba histolytica strain HM-1:IMSS, and showed specific reaction against 30,000 Mr antigen of pathogenic isolates.We examined the reactivity of McAb 4G6 to trophozoites isolated from acute amoebic dysentery or cyst carriers using the indirect fluorescent-antibody test(IFA). Zymodeme analysis was carried out by starch gel electrophoresis.Results showed that McAb 4G6 reacted with the SH-8 strain derived from patient with fever, diarrhea and purulent bloodly-stool.The titer of pooled ascitic fluids was 5 120.Isoenzyme pattern analysis showed it to belong to the pathogenic zymodme Ⅱ. By contrast, McAb 4G6 failed to react with SH-3or SH-6 strain isolated from patients with fever and diarrhea but without purulent discharge, or SH-5,SH-7 strain isolated from cyst carriers. The result of zymodeme analsis showed that these 4 strains of E.histolytica belonged to nonpathogenic zymodeme Ⅰ.This fact suggeste that there are immunological differences between pathogenic and non-pathogenic isolates and that McAb 4G6 can be useful in the identification of pathogenic amoeba. This result also suggests that IFA with McAb is useful for the accurate detection of pathogenic amoeba.It is shown that IFA is a simple economical and rapid method for testing McAb reactivity to amoebic trophozoite, and it useful for epidemiological investigations on amoebiasis.