"Stapling" scFv for multispecific biotherapeutics of superior properties.

Single-chain fragment variable (scFv) domains play an important role in antibody-based therapeutic modalities, such as bispecifics, multispecifics and chimeric antigen receptor T cells or natural killer cells. However, scFv domains exhibit lower stability and increased risk of aggregation due to transient dissociation ("breathing") and inter-molecular reassociation of the two domains (VL and VH). We designed a novel strategy, referred to as stapling, that introduces two disulfide bonds between the scFv linker and the two variable domains to minimize scFv breathing.

Serologic assay to quantify human immunoglobulin G antibodies to the Staphylococcus aureus iron surface determinant B antigen.

A direct binding Luminex assay has been developed and validated for the detection of human immunoglobulin G (IgG) antibodies to the Staphylococcus aureus iron surface determinant B protein (IsdB) in serum following natural infection or immunization with investigational Saccharomyces cerevisiae-derived IsdB-based vaccines. To ensure that IsdB-specific IgG antibodies are measured following immunization with S. cerevisiae-derived IsdB, an Escherichia coli-produced IsdB antigen is used in the assay.