Neutralization of Lethal Potency of Tetanus Toxin using Phage Display Produced scFv Antibody

Phage display technology provides a new approach for making human antibody fragments that could be applicable in passive immune therapy. We applied the use of this technology to make human single-chain variable fragments (scFvs)specific for tetanus toxin.Tetanus toxin is a neurotoxin constituted by the association of two subunits, mediates its lethal action by blocking neuromuscular vesicle docking.

We previously found that six Human scFvclones inhibit toxin binding to ganglioside GT1b. This is the final report of human tetanus scFvs (scFv 8 and scFv 13) isolated from an immunized library of more than 106 scFv clones with in vivo neutralizing activity.

Only scFv 13 can reduce the in vivo toxicity induced by tetanus toxin. Also, scFv 8 has a weak capability of reducing the in vivo toxicity of the toxin.

These selected ScFvscan be considered as a possible option to substitute the human tetanus immunoglobulin (HTIG) which is extensively current immunotherapy for tetanus patients. Taken together, our results suggest that the use of human tetanus scFvs may lead to a less aggressive passive immune therapy against tetanus.