Human antibody production in transgenic animals

Area of Science:

• Immunology
• Biotechnology
• Genetics

Background:

• Fully human antibodies derived from transgenic animals are crucial for developing new therapeutics.
• Transgenic rodents and large animals like cattle can produce high-affinity human monoclonal antibodies and specific human immunoglobulin (Ig).

Purpose of the Study:

• To investigate strategies for deriving animals expressing diverse human antibody repertoires.
• To address suboptimal production of fully human antibodies compared to wild-type Ig.
• To identify methods for improving immune response and antibody yield in transgenic systems.

Main Methods:

• Integration of human immunoglobulin gene loci using bacterial artificial chromosomes or yeast artificial chromosomes via oocyte microinjection or ES cell transfection.
• Derivation of ruminants from manipulated fibroblasts with integrated human chromosome fragments or artificial chromosomes.
• Gene targeting in ES or fibroblast cells, or zinc finger technology, to silence endogenous Ig loci.
• Linking human V-region genes to endogenous CH-regions via large constructs or site-specific integration.
• Knocking out endogenous Ig loci and integrating large human IgH loci.

Main Results:

• Silencing endogenous Ig loci was essential for optimal production in all animal strains.
• Fully human antibodies were produced less efficiently than wild-type Ig due to imperfect interaction of human constant regions with endogenous signaling components.
• Linking human V-region genes to endogenous CH-regions significantly improved antibody production and yield.
• Animals with knocked-out Ig loci and integrated large human IgH loci achieved highly diverse human antibody production comparable to normal animals.

Conclusions:

• Strategies involving gene targeting and the integration of large human immunoglobulin loci are effective for producing diverse, high-affinity fully human antibodies in transgenic animals.
• Optimizing the interaction between human antibody V-regions and endogenous signaling components is key to enhancing production efficiency.
• Transgenic animal models offer a powerful platform for the development of human antibody-based therapeutics.