Half-Life Extension of the IgG-Degrading Enzyme (IdeS) Using Fc-Fusion Technology.

Imlifidase (IdeS) is a bacterial protease that hydrolyzes human IgG in their hinge region, decreasing their half-life and abrogating their Fc-mediated properties. It is now successfully used in therapy to prevent graft rejection during kidney transplants and is being clinically evaluated in several IgG-mediated autoimmune diseases. IdeS short half-life however limits its clinical use, particularly in the case of chronic diseases that would request repeated administrations.

Enhancing the detection of an anti-SAG1 scFv-alkaline phosphatase immunoconjugate.

The purpose of this study was to implement a fluorometric method for enhancing the detection sensitivity of in biological fluids. To address this challenge, we designed and produced a recombinant immunoconjugate tool based on a single-chain antibody fragment anti- SAG1 antigen (scFvSG15) genetically fused to the bacterial alkaline phosphatase (AP) using 4-methyl-umbelliferyl-phosphate as fluorogenic substrate. The anti-SAG1 scFv-AP conjugate was fully bifunctional and was used successfully in different assays including immunoblot, fluorometric ELISA and direct immunofluorescence.