Snakebite is an important public health problem in tropical and subtropical regions. Macrovipera lebetina
is one of the most dangerous snakes in Iran. Envenoming by this snake
can lead to respiratory distress, heart attack, bleeding, and death. The
specific treatment available is immunized equine serum, which has
several side effects like serum sickness. Nowadays, single-chain fragment variable antibodies (scFvs) are one of the fast growing classes of monoclonal antibodies, which are suggested for treatment of envenoming. This study aimed to achieve a fully human scFv antibody against M. lebetina venom from human non-immune library. In this study, scFvs against M. lebetina venom were isolated by phage display
technique. Using three rounds of biopanning, two specific scFvs (C37
and C69) with the highest affinity were selected. The selected scFvs
purified by nickel affinity chromatography. The specific binding of purified antibodies were confirmed by enzyme-linked immunosorbent assay. The LD50 as well as HD50
concentration of the crude venom were obtained to be 45 μg and
120 μg/ml, respectively. C69 neutralized 48% of the hemolysis activity
of M. lebetina venom and C37 survived 66% of mice after 115 min
of envenoming. Taken together, the results indicate the potential of
human non-immune libraries for selection of functional antibodies
against M. lebetina venom.