en 30090206 <p>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 <em>Escherichia coli (E. coli)</em> 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 <em>E. coli</em>.<br /> Methods: For this purpose, the fragment coding for anti-CD20 huscFv subcloned into the pET22b (+) and transformed into the <em>E. coli</em> 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.&nbsp;<br /> 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 325 <em>&micro;g/ml</em> soluble anti-CD20 scFv.&nbsp;<br /> Conclusion: The result of this study demonstrated remarkable effect of pKJE7 chaperone on enhancement of soluble expression of anti-CD20 huscFv antibody in <em>E. coli</em>.</p> Molecular chaperones, Non Hodgkin lymphoma, Single chain antibody 141 146 https://www.ajmb.org/En/Article.aspx?id=318 https://www.ajmb.org/PDF/En/FullText/318.pdf MohammadrezaYousefiDrug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran1277SafarFarajniaDrug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran1278AhadMokhtarzadehFaculty of Medicine, Gonabad University of Medical Sciences, Gonabad, Iran1279BahmanAkbariDepartment of Medical Biotechnology, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran1280ShivaAhdi KhosroshahiBiotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran1281MinaMamipourDepartment of Biotechnology, Higher Education Institute of Rab-Rashid, Tabriz, Iran1282HassanDariushnejadImmunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran1283VahidehAhmadzadehBiotechnology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran11433