Generation of a highly stable, internalizing anti-CD22 single-chain Fv fragment for targeting non-Hodgkin's lymphoma.

The generation of a single chain Fv (scFv) fragment derived from the anti-CD22 monoclonal antibody LL2 resulted in a molecule with good antigen binding but very poor stability properties, thus hampering its clinical applicability. Here we report on the construction of an engineered LL2 scFv fragment by rational mutagenesis. The contribution of uncommon wild-type sequence residues for providing stability to the conserved common core structure of immunoglobulins was examined.