High expression of recombinant human catalase and its immunomodulatory effects on H1N1 influenza virus infection

• Published in: Process biochemistry (1991) Vol. 48; no. 4; pp. 588 - 592
• Main Authors: Shi, Xun-Long, Shi, Zhi-Hui, Feng, Mei-Qing, Ye, Li, Zhu, Hai-Yan, Li, Ji-Yang, Ju, Dian-Wen, Zhou, Pei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.04.2013
• Subjects: animal models; antioxidants; bioreactors; catalase; dose response; H1N1 influenza virus; Human catalase; human diseases; humans; immunomodulation; Immunomodulatory activity; Influenza A virus; Influenza virus; lungs; phagocytosis; Phagocytotic and mononuclear phagocytic system; Pichia pastoris; pneumonia; Recombinant; recombinant proteins; spleen; therapeutics; thymus gland; viral load; Western blotting; H1N1 influenza virus; Human catalase; Immunomodulatory activity; Phagocytotic and mononuclear phagocytic system; Pichia pastoris; Recombinant
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2013.01.002

► Overexpression of recombinant human catalase. ► Simpler purification procedure of rhCAT. ► rhCAT inhibited influenza virus replication. ► rhCAT activated the phagocytotic function of mononuclear phagocytic system. Catalase is a key antioxidant enzyme and has been implicated in many pathophysiological processes of human diseases. In a previous study, we developed a yeast-based expression system for recombinant human catalase (rhCAT), and proved its therapeutic effects for treating H1N1 virus-induced pneumonia. However, the preparation of rhCAT was insufficient for further research applications. Here, we describe a much more convenient construction strategy for rhCAT based on the Pichia pastoris GS115 strain in a 14L bioreactor. Quantitative-PCR, Western blotting, and activity assay were used to demonstrate the stable and efficient high-level expression (1500U/mL; 77% recovery) achieved by this newly developed simple two-step purification procedure. The rhCAT synthesized by this new procedure was applied to an H1N1-infected mouse model (doses of 50 and 100kU/mice/day) to assess its capabilities for inducing immunomodulatory effects. The results showed that the rhCAT could restore the impaired phagocytosis, alleviate the induced reductions in spleen and thymus organ weights, and markedly reduce the lung tissue viral load, all in a dose-dependent manner. Thus, this study provides not only a simple method for large-scale preparation of active rhCAT, but also in vivo evidence of the recombinant protein's immunomodulatory activity which may have clinical applications in treating H1N1 or other viral infections.