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Construction and evaluation of wild and mutant ofatumumab scFvs against the human CD20 antigen
Reza Maleki1, Azam Rahimpour2, Masoumeh Rajabibazl1
1Department of Clinical Biochemistry, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Several monoclonal antibodies targeting the CD20 have been produced and Ofatumumab is a case in point. Although whole antibodies target cancer cells effectively, their applications are restricted in some ways. Single-chain fragment variable antibodies, rather than employing the entire structure of antibodies, have proven a practical approach for creating completely functional antigen-binding fragments. In current research, the DNA coding sequence of and of the wild and mutant forms of ofatumumab were joined with a flexible linker separately. Using the E. coli BL21 (DE3) expression system, the -linker- genes were cloned into the pET-28 a (+), and the associated recombinant proteins were produced. Purified and refolded scFvs (scFv-C and scFv-) represented a concentration of around 0.7 mg/ml from 1 L of initial E. coli culture with a molecular weight of about 27 kDa. Affinity measurement disclosed anti-CD20 scFv- possesses a higher affinity constant compared to anti-CD20 scFv- The recombinant scFvs exclusively attach to Raji cells but not to Jurkat cells, according to a cell-ELISA analysis. The MTT test signified anti-CD20 scFvs could affect cell viability in Raji cells but had no impact on Jurkat cells and also, Raji cells viability was affected more significantly by anti-CD20 scFv-
Several monoclonal antibodies targeting the CD20 have been produced and Ofatumumab is a case in point. Although whole antibodies target cancer cells effectively, their applications are restricted in some ways. Single-chain fragment variable antibodies, rather than employing the entire structure of antibodies, have proven a practical approach for creating completely functional antigen-binding fragments. In current research, the DNA coding sequence of and of the wild and mutant forms of ofatumumab were joined with a flexible linker separately. Using the E. coli BL21 (DE3) expression system, the -linker- genes were cloned into the pET-28 a (+), and the associated recombinant proteins were produced. Purified and refolded scFvs (scFv-C and scFv-) represented a concentration of around 0.7 mg/ml from 1 L of initial E. coli culture with a molecular weight of about 27 kDa. Affinity measurement disclosed anti-CD20 scFv- possesses a higher affinity constant compared to anti-CD20 scFv- The recombinant scFvs exclusively attach to Raji cells but not to Jurkat cells, according to a cell-ELISA analysis. The MTT test signified anti-CD20 scFvs could affect cell viability in Raji cells but had no impact on Jurkat cells and also, Raji cells viability was affected more significantly by anti-CD20 scFv-

