Cloning and Expression of human IL-11 in E. coli

Interleukin-11 (IL-11) is a thrombopoietic growth factor that stimulates the proliferation of hematopoietic stem cells and megakaryocytes and induces megakaryocyte maturation resulting in increased platelet production. IL-11 has recently been approved for treatment of chemotherapy induced thrombocytopenia in cancer patients. This cytokine is the first growth factor that gained FDA approval for this application. The aim of this study was cloning and recombinant expression of human IL-11 in E. coli. RNA was extracted from a human bone marrow sample and used for cDNA synthesis. cDNA was applied for amplification of IL-11 gene by PCR. The PCR product was cloned, sequenced and expressed in E. coli using pET28a expression vector. Amplification of human IL-11 gene using primers designed on mature full length coding region of IL-11 resulted in a 531 bp fragment as visualized by agarose gel electrophoresis. Sequencing of the cloned fragment confirmed the identity of sequence of cloned gene. Expression by pET28a vector resulted in a high level production of recombinant IL-11 which appeared as a 24 kDa protein in the SDS-PAGE analysis of induced culture. The result of the present study indicated that the E. coli expression system is a suitable expression system for recombinant expression of human IL-11 and could be used for mass production of this cytokine due to high-density cell growth and fast product formation.