title: Expression, purification and identification of recombinant mouse interleukin 21 protein in E. coli.
abstract: Interleukin 21 (IL-21) is a novel type I cytokine that is significantly homologous to IL-2, IL-4 and IL-15. Its receptor complex contains gammac chain which is also a component of receptors for IL-2, IL-4, IL-7, IL-9 and IL-15, so there may be overlapping or relevancies in their biological functions. IL-21 is capable of co-stimulating mature T cells, B cells, NK cells, and of stimulating CD16 expression on the surface of NK cells to induce ADCC in innate immune response. It can also strengthen the anti-tumor effect of the cellular immunity, especially via enhancing the activities of NK and antigen specific CTL cells. Thus, IL-21 is a potential useful therapeutic molecule for immunotherapy of malignancies, by eliciting innate and adaptive anti-tumor responses in tumor-bearing hosts. In order to study the biological functions of IL-21, we constructed a mIL-21 prokaryotic expression plasmid and expressed the recombinant mIL-21 protein in E. coli in present study. The recombinant plasmid pET28a/mIL-21 with a carboxyl terminal His-tag was subcloned from the pcDNA3.1/mIL-21 and expressed in E. coli. The induced protein was detected by SDS-PAGE, and identified by Western-blot assay with anti-mIL-21 antibody. The recombinant protein was purified via Ni+ affinity chromatography, and renatured with GSH/GSSG system. Our mouse T cell proliferation experiment showed that the recombinant mIL-21 protein could enhance the mouse T cell proliferation either by itself alone or in the presence of Con A.
authors.affiliation: School of Life Science and Technology, China Pharmaceutical University, China.
authors.forename: Weiguo
authors.initials: W
authors.lastname: Tang
authors.forename: Guobing
authors.initials: G
authors.lastname: Chen
authors.forename: Qing
authors.initials: Q
authors.lastname: Gu
authors.forename: Jing
authors.initials: J
authors.lastname: Pan
authors.forename: Wutong
authors.initials: W
authors.lastname: Wu
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D005822:Genetic Vectors; D007378:Interleukins / Q000096:biosynthesis* / Q000235:genetics / Q000302:isolation & purification*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D020673:Protein Renaturation; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000302:isolation & purification; D013154:Spleen / Q000166:cytology; D000098546:Interleukin-21
chemical_list: D007378:Interleukins; D011994:Recombinant Proteins; D000098546:Interleukin-21