Production and Characterization of Human Immunoglobulin Producing Goats for Diagnostic Reagents and Therapeutics

Project Summary/Abstract
The ultimate goal of this phase II STTR proposal is to expand the capabilities of SABandapos;s diversitAb™ platform by
continuing advanced development of Transchromosomic goats (TcGs). This will be accomplished by producing
male and female goat endogenous immunoglobulin gene knockout cell lines that contain SAB Capraandapos;s human
artificial chromosome (HAC) which encodes the entire repertoire of the germline human antibody genes thereby
greatly improving the production efficiency of fully human antibodies in TcGs. To further advance the TcG
platform towards commercial production of therapeutic and diagnostic antibody products, optimization of the
antibody purification process, development of quality control assays, and further development of a purified TcG-
derived pandemic influenza antibody product targeting H7N9 by completing in-vitro and in-vivo evaluation is also
proposed.
To accomplish these goals, endogenous immunoglobulin gene knockouts will be facilitated utilizing the
CRISPR/Cas9 system in domestic Nubian/Boar goat fetal fibroblast (GFF) cells, and transfer of the SAB-
designed HAC into the knockout cells will be accomplished by microcell mediated chromosome transfer (MMCT).
HAC-containing knockout GFF cells will be used to produce embryos by somatic cell nuclear transfer (SCNT).
After gestation and birth of multiple TcGs, molecular characterization will be completed, presence of the
knockouts and HAC will be confirmed, and human IgG production will be confirmed and evaluated. Two of these
TcGs will then be hyperimmunized with a plasmid DNA vaccine targeting H7N9. Plasma will be collected from
the hyperimmunized TcGs, and anti-H7N9 fully human IgG will be purified from the TcG plasma. The in-vitro
potency and in-vivo efficacy of the purified TcG-derived anti-H7N9 human IgG product will then be evaluated.
Optimization of established purification procedures will be undertaken to ensure efficient and effective purification
of TcG-derived human IgG from plasma, and development of quality control assays to evaluate product identity,
purity, and potency will be completed.
SABandapos;s diversitAb™ platform for human antibody production is currently utilized in transchromosomic bovines
against a wide range of antigens including viruses, bacteria, oncology targets, recombinant proteins, and DNA
vaccines. This proven technology has the advantages of scalability, simplicity, and broad applicability. The
addition of TcGs to the platform allows for simpler and cheaper rapid-response production of small volume
targeted products as well as diagnostic reagents for serological testing of emerging infectious diseases.Project Narrative
The research proposed in this application seeks to expand the capabilities of SABandapos;s diversitAb™ platform by
continuing advanced development of Transchromosomic goats (TcGs) that express human polyclonal antibodies
for use as targeted immunotherapies and/or diagnostic reagents for serological testing. Immunotherapy products
derived from TcGs will combine the beneficial effects of current animal derived antibody products with improved
efficacy and safety while eliminating the risk of anaphylaxis and serum sickness associated with xenobiotic IgG
administration. A TcG-derived anti-H7N9 fully human IgG product will also be developed through this proposal,
potentially addressing the global need for highly effective therapeutics against avian lineage influenza virus
infections in humans.