Robert E. Bird

[4] Construction of single-chain Fv derivatives of monoclonal antibodies and their production in Escherichia coli

Publisher Summary This chapter focuses on genetic and protein engineering applied to immunoglobulin molecules that have produced novel new ways of generating and preserving specificities. The generality of the single-chain Fv (scFv) technology is based on the observation that the basic structure of the individual immunoglobulin domains is conserved in all antibodies. It is then assumed that this framework structure is sufficiently stable that, as long as a linker or other adjoining region does not interfere with the domain structure and the ability of the V L and V H to associate, the individual domains will fold and associate to form a molecule that mimicks the antigen combining region of an antibody heterodimer. A scFv molecule consists of the variable domains of an antibody tethered together by a designed protein linker such that the antigen combining site is regenerated in a single protein. Applications under development include the use of genetic fusions of scFvs to potent toxins and the use of radiolabeled scFv molecules to image tumors that express antigens recognized by the scFv. The incorporation of scFv into a genetic fusion with other functional polypeptides or other scFvs has the potential to generate novel and useful functional combinations.

New concepts in monoclonal antibody based radioimmunodiagnosis and radioimmunotherapy of carcinoma

It is now generally agreed that while numerous monoclonal antibodies (MAbs) have been shown to efficiently target tumors in patients, much still needs to be accomplished to optimize MAb based tumor targeting and the use of MAbs in the therapy of human carcinoma. This article will review some recent studies undertaken in our laboratory in an attempt to generate novel recombinant constructs and test new principles to aid in optimizing MAb based diagnosis and therapy. Three areas will be covered: (a) the analysis of dose fractionation protocols; (b) the generation of recombinant/chimeric (rec/chi) MAbs including the generation of a single chain antigen binding protein (SCA); and (c) the use of recombinant interferons (rec IFNs) to selectively up-regulate tumor antigen expression. Each of these topics has been previously described in detail and appropriate references to these articles are included.