柔红霉素与抗兔晶状体上皮细胞单克隆抗体偶联物的制备及其免疫学特性

Preparation and immunological characteristic of an monoclonal antibody and daunorubicin conjugate on rabbit lens epithelial cells

目的 评价柔红霉素(daunorubicin,DNR)与抗兔晶状体上皮细胞单克隆抗体免疫偶联物对兔晶状体上皮细胞的免疫特异性。方法 采用过碘酸盐氧化法将抗兔晶状体上皮细胞单克隆抗体LM_1与柔红霉素结合;Bradford蛋白检测法和紫外吸收光谱法检测偶联物中LM_1与DNR的克分子比;ELISA法检测LM_1与DNR偶联后抗体活性的变化;免疫组织化学法检测偶联物在兔眼组织的免疫特异性。结果 偶联物表现出单抗LM_1和DNR的生物学活性及紫外光谱特征,偶联产物中DNR与LM_1的克分子比约为12∶1,即每个抗体分子可以携带约12个药物分子。偶联后抗体的活性保持为原有活性的76.5％以上。免疫组化显示偶联物仅在兔晶状体上皮细胞呈阳性表达,在其他眼组织为阴性表现。结论 抗兔晶状体上皮细胞单克隆抗体与柔红霉素的免疫偶联物在体外可以选择性地结合到兔晶状体上皮细胞并保持特异的免疫活性。

Objective To evaluate the immunological characterization of daunorubiciri (DNR) coupled to monoclonal antibodies (McAb) reactive with rabbit lens epithelial cells (LECs). Methods A murine monoclonal antibody LMj reactive with rabbit lens epithelial cells was conjugated to DNR via sodium periodate oxidation method. The molar ratio of LM1 and DNR in the conjugate was measured by Bradford protein assay and UV absorption spectra assay. The immunological activity of the antibody in conjugate was assessed by ELISA. The specific binding characterization on rabbit eye tissue was evaluated by immunohistochemistry method. Results The conjugate showed biological activities and UV spectra characteristics of DNR and McAb LMi. The molar ratio of LMi to DNR in the conjugate was 12 : 1. That meant each McAb molecular could carry 12 drug moleculars in the conjugate. The immunological activity of antibody in the conjugate retained more than 76. 5% of the original McAb LMi. Immunohistochemistry assay revealed .that positive staining of antibody expression only was shown in rabbit LECs but negative staining in other eye tissue. Conclusion It is suggested that the immunoconjugate of McAb LMi linked to DNR have retained specific immunological activity and exhibited selective binding to rabbit LECs in vitro.