ELPylated Anti-human TNF Therapeutic Single-domain Antibodies for Prevention of Lethal Septic Shock

Tumour necrosis factor (TNF) is a major pro-inflammatory cytokine involved in multiple inflammatory diseases. The detrimental activity of TNF can be blocked by various antagonists, and commercial therapeutics based upon this principle have been approved for treatment of diseases including rheumatoid arthritis, Crohn's disease and psoriasis. In a search for new, improved anti-inflammatory therapeutics we have designed a single-domain monoclonal antibody (V(H) H), which recognizes TNF. The antibody component (TNF-V(H) H) is based upon an anti-human TNF Camelidae heavy-chain monoclonal antibody, which was linked to an elastin-like polypeptide (ELP). We demonstrate that ELP fusion to the TNF-V(H) H enhances accumulation of the fusion protein during biomanufacturing in transgenic tobacco plants. With this study, we show for the first time that this plant-derived anti-human TNF-V(H) H antibody was biologically active in vivo. Therefore, therapeutic application of TNF-V(H) H-ELP fusion protein was tested in humanized TNF mice and was shown to be effective in preventing death caused by septic shock. The in vivo persistence of the ELPylated antibody was ∼24 fold longer than that of non-ELPylated TNF-V(H) H.