抗隐孢子虫单克隆抗体免疫保护机理的初探

PRELIMIMARY STUDY ON IMMUNOPROTECTIVE MECHANISM OF THE MONOCLONAL ANTIBODY AGAINST CRYPTROSPORIDIUM

探讨抗隐孢子虫单克隆抗体（MCAb）的作用机理。方法检测接种经McAb处理的CSP的宿主MDCK细胞内游离钙离子浓度（［Ca2+]i和细胞膜Na+一K+一ATP酶活性，以及采用3H—TdR掺入法和细胞流式议（FCM）测定宿主MDCK细胞DNA含量。结果与对照组比较，McAbZ3D2不仅可使［Ca2+］i明显降低，以及膜Na+一K+一ATP酶活性增高（P＜0．o1），而且可使MDCK细胞的DNA含量及DNA合成率增高（P<0．01）。结论McAbZ3D2的作用机理可能是中和CSP敏感表位，使跨膜信号［Ca2+］i减少，从而维持细胞膜完整性，达到保护宿主细胞的作用。

Aim To investigate the mechanisms of the action of monoclonal antibody (McAb )againtCryptrosporidium (CS). Methods lntracellular free calcium ([Ca2+]i ) concentration and membrane Na+ -- K+-ATPase activity,as well as the DNA content detcted by using 3H--TdR and flow cytometry techniques werestud-ied in MDCK cells infected with CSP. Results The lower[Ca2+]i concentration, the higher membrane Na+ --K+--ATPase activity (P<0. 01 ),the higher DNA content,and DNA synthesis rate(p<0. 01 ) were demonstrated inMDCK cells treated with Z3D2 compared with controls. Conclusion These data indicated that the protectiveac-tion of McAb Z3D2 might be related to reduction of [Ca2+]i transmembrane signal and maintenance of the integralcell membrane by neutralizing the sensitive epitopes on cell surface of CS.