A rice-based soluble form of a murine TNF-specific llama variable domain of heavy-chain antibody suppresses collagen-induced arthritis in mice

摘要

Tumor necrosis factor alpha (TNF) plays a pivotal role in chronic inflammatory diseases such as rheumatoid arthritis and Crohn's disease. Although anti-TNF antibody therapy is now commonly used to treatpatients suffering from these inflammatory conditions, the cost of treatment continues to be a concern. Here, we developed a rice transgenic system for the production of a llama variable domain ofa heavy-chain antibody fragment (VHH) specific for mouse TNF in rice seeds (MucoRice-mTNF-VHH). MucoRice-mTNF-VHH was produced at high levels in the rice seeds when we used our most recenttransgeneoverexpression system with RNA interference technology that suppresses the production ofmajor rice endogenous storage proteins while enhancing the expression of the transgene- derived protein. Production levels of mTNF-VHH in rice seeds reached an average of 1.45% (w/w). Further, approximately91% of mTNF-VHH was released easily when the powder form of MucoRice- mTNF-VHH was mixed withPBS. mTNF-VHH purified by means of single-step gel filtration from rice PBS extract showed high neutralizing activity in an in vitro mTNF cytotoxicity assay using WEHI164 cells. In addition, purified mTNF-VHH suppressed progression of collagen-induced arthritis in mice. These results show that this rice- expressionsystem is useful for the production of neutralizing VHH antibody specific for mTNF. (C) 2014 Elsevier B.V. All rights reserved.