High-affinity, human antibody-like antibody fragment (single-chain variable fragment) neutralizing the lethal factor (LF) of Bacillus anthracis by inhibiting protective antigen-LF complex formation.

ABSTRACT: The anthrax lethal toxin (LT) consists of two subunits, the protective antigen (PA) and the lethal factor (LF), and is essential for anthrax pathogenesis. Several recombinant antibodies directed against PA and intended for medical use have been obtained, but none against LF, despite the recommendations of anthrax experts. Here we describe an anti-LF single-chain variable fragment (scFv) that originated from an immunized macaque (Macaca fascicularis) and was obtained by phage display. Panning of the library of 1.8 x 10(8) clones allowed the isolation of 2LF, a high-affinity (equilibrium dissociation constant, 1.02 nM) scFv, which is highly neutralizing in the standardized in vitro assay (50% inhibitory concentration, 1.20 +/- 0.06 nM) and in an in vivo assay. The scFv neutralizes anthrax LT

SUBMITTER: Pelat T 

PROVIDER: S-EPMC1932538 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature