内毒素核心糖脂单克隆抗体的血清学反应性及保护作用的初步研究

Serological Cross-reactivities and Protective Activities of Monoclonal Antibodies against Core Glycolipide of Salmonella Minnesota R595

以S.minnesota R595菌为免疫原,通过细胞融合获得8株分泌抗核心糖脂单抗的杂交瘤细胞系。对其中的两株代表性单抗2D6E7和3H4 2F7的血清学反应性以及在小鼠Hb/Mu腹腔感染模型中的保护作用进行了初步研究。菌体吸收试验和间接免疫荧光试验(ⅡF)表明,单抗能与多种革兰氏阴性杆菌(GNB)产生交叉反应,并且光滑型GNB的煮沸菌体荧光染色呈阳性,活菌染色呈阴性。保护性试验结果表明,3H4 2F7单抗能显著提高S.minnesota(野生菌株),鼠伤寒杆菌和E.Coli等光滑型GNB攻击的小鼠存活率(P<0.05),显示出抗核心糖脂单抗的良好交叉保护作用。若攻击前、后2h或攻击同时输入单抗3H4 2F7,对光滑型GNB的感染均有明显保护效果(P<0.05);2D6 E7单抗未表现有保护活性。

Eight hybridoma cell lines secreting monoclonal antibodies against core glycolipide of Salmonella minnesota R595 were obtained by fusion of Sp2/0 myeloma cells with spleen tells from BALB/c mice immunized with heat-killed whole cells of R595. In vitro serological cross-reactivities of two McAbs, 2D6E7 and 3H4 2F7 and their in vivo cross protection against peritoneal infection by Gram-negative bacilli (GNBs) were investigated by using murine Hb/Mu model. The results of adsorption test and indirect immunofluorescence (ⅡF) showed that these McAbs cross-reacted with various GNBs other than S. minnesota and boiled smooth GNBs were positively stained by ⅡF while viable smooth GNBs were negatively stained. Preliminary study on the protectivities of the two McAbs demonstrated that, when administered at 2 h before and after or during the bacterial challenge, McAb 3H42F7 significantly increased the survival rate of mice challenged with some heterologous GNBs such as S. minnesota wild strain, S. typhimurium wild strain and E. coli clinical isolate (p<0.05) which confirmed cross-protective activities of anti-core LPS antibodies. In the mean-, while, McAb 2D6E7 showed no significant protection in this model (p>0.05).