Expression and activity of the chermic F(ab')_2 fragment of anti-CD20 antibody / 中国免疫学杂志

ABSTRACT

Objective:To highly express the secretory gene engineering anti CD20F(ab') 2 in the E.coli,simplify working processes and enhance the bioactivity of the antibody fragment.Methods:Using the single factor analysis to optimize the ferment parameters.A culture method which most suit for E.coli secreting anti CD20F(ab') 2 was selected.The anti CD20F(ab') 2 was extracted from periplasm then purified it using the strptococal protein G affinity colume and the S200 HR size exclusion chromatography.The activity of anti CD20F(ab') 2 inhibiting the growth of cell Daudi in vitro was eamined using MTT.Results:Using the optimized culture method,the yield of anti CD20F(ab') 2 was distinctly enhanced from 1.9～2.2 mg/L to 3.7～4.3 mg/L and the proportion of anti CD20F(ab') 2 in all the extract also was improved from 9.7～13.2% to 38.1%～46.8%.After the S200 HR size exclusion chromatography,the purity of anti CD20F(ab') 2 could exceed 85%.The outcome of MTT exmiination showed the IC 50 of anti CD20F(ab') 2 and Fab' were 14.6 ?g/ml and 39.5 ?g/ml,respectively.Conclusion:The gene engineering anti CD20F(ab') 2 could highly express in the E.coli by using the optimized culture method.The anti CD20F(ab') 2 inhibited the growth of Daudi cells in vitro more strong than anti CD20Fab'.