摘要
为建立一种高效碘标单克隆抗体HAb18法,以溴代琥珀酰亚胺(NBS)为氧化剂,传统氯胺T法为对照,对产物^(125)I-HAb18的标记率、比活度、免疫活性、体外稳定性及在荷人肝癌裸鼠体内的生物分布等进行评价。结果NBS标记率为83%～92%,比活度0.56～2.00MBq/μg,标记率随NBS用量增加而增高,最佳用量比为抗体(μg):^(125)I(MBq):NBS(μg)=5:12:1;^(125)I-HAb18的免疫活性分数为0.54～0.72,随比活度增高而下降;亲和常数为8.17×10~9L/mol;体外-20℃存放5天放化纯度和免疫活性分别降至原来的80%和40%;两种标记法的生物分布差异无显著性(P>0.05)。结果表明,该法可高效碘标记单克隆抗体,标记后无需纯化,特别适合大剂量^(131)I标记。
PURPOSE To develop a method of high efficiency iodination of McAb HAb18 which needn't to be purified. METHODS An anti-hepatocellular carcinoma (HCC) McAb HAb18 was iodinated using N-bromosuccinimide (NBS) as oxidant. The conventional chloramine T(Ch-T) method was used as control. Labeling condition of NBS method was optimized and radiolableled conjugate ^(125)I-HAb18 was assessed in labeling efficiency, specific activity, immunoreaetivity, in vitro stability and biodistribution in hepatoma xenografted nude mice. RESULTS 1) The labeling efficiency increased as the amount of NBS increased, ranged from 83% to 92%; specific activity could reach up to 2.00 MB_(q/μg); 2) The immunoreactivity fraction (r) reduced as the specific activity increased, ranged from 0.54 to 0.72 and the optimal ratio of antibody (μg) : ^(125)I(MBq): NBS(μg) was 5:12:1; 3) The affinity constant Ka of ^(125)I-HAb18, measured by Scatchard plot, was 8.17×10~9L/mol; 4) The radiochemical purity of ^(125)I-HAb18 reduced to 80% and only 40% of initial cell binding rate remained after 5 days in vitro storage (-20℃); 5) No significant difference in biodistribution was observed between the NBS and conventional Ch-T method (P>0.05). CONCLUSIONS NBS method was a high efficiency iodination of McAb and especially suitable for high dose ^(131)I labeling in RIT.
出处
《中华核医学杂志》
CAS
CSCD
北大核心
1996年第2期95-97,共3页
Chinese Journal of Nuclear Medicine
基金
国家"863"计划资助
关键词
单克隆抗体
肝肿瘤
碘
同位素标记
Antibodies,monoclonal Liver neoplasms Iodine radioisotopes Isotope Labeling
