Soluble expression of humanized anti-cd20 single chain antibody in escherichia coli by cytoplasmic chaperones co-expression

Background: CD20 is an important cell surface receptor that is used for target therapy of B cell lymphoma and some related blood diseases due to vital function of CD20. In previous studies, a Rituximab based humanized single chain variable fragment [scFv] antibody showed good reactivity against B cell related cancer cells. But this recombinant protein produced Inclusion Bodies [IBs] in Escherichia coli [E. coli] cytoplasm .The aim of this study was to investigate the effect of coexpression with cytoplasmic chaperones on expression and solubility of humanized anti-CD20 scFv in E. coli

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Methods: For this purpose, the fragment coding for anti-CD20 huscFv subcloned into the pET22b [+] and transformed into the E. coli BL21 [DE3] was evaluated. In order to inhibit the production of IBs, the effects of co-expression with cytoplasmic chaperones GroEL, DnaK, GroES, Tig, DnaJ and GrpE were investigated

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Result: Coexpression with cytoplasmic chaperones led to increased soluble expression of anti-CD20 recombinant protein. Among investigated chaperones, pKJE7 chaperone plasmid containing DnaJ, GrpE, DnaK chaperone genes had significant effects with an expression yield of 325Mug/ml soluble anti-CD20 scFv

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Conclusion: The result of this study demonstrated remarkable effect of pKJE7 chaperone on enhancement of soluble expression of anti-CD20 huscFv antibody in E. coli