title: Species-Specific Chromosome Engineering Greatly Improves Fully Human Polyclonal Antibody Production Profile in Cattle.
abstract: Large-scale production of fully human IgG (hIgG) or human polyclonal antibodies (hpAbs) by transgenic animals could be useful for human therapy. However, production level of hpAbs in transgenic animals is generally very low, probably due to the fact that evolutionarily unique interspecies-incompatible genomic sequences between human and non-human host species may impede high production of fully hIgG in the non-human environment. To address this issue, we performed species-specific human artificial chromosome (HAC) engineering and tested these engineered HAC in cattle. Our previous study has demonstrated that site-specific genomic chimerization of pre-B cell receptor/B cell receptor (pre-BCR/BCR) components on HAC vectors significantly improves human IgG expression in cattle where the endogenous bovine immunoglobulin genes were knocked out. In this report, hIgG1 class switch regulatory elements were subjected to site-specific genomic chimerization on HAC vectors to further enhance hIgG expression and improve hIgG subclass distribution in cattle. These species-specific modifications in a chromosome scale resulted in much higher production levels of fully hIgG of up to 15 g/L in sera or plasma, the highest ever reported for a transgenic animal system. Transchromosomic (Tc) cattle containing engineered HAC vectors generated hpAbs with high titers against human-origin antigens following immunization. This study clearly demonstrates that species-specific sequence differences in pre-BCR/BCR components and IgG1 class switch regulatory elements between human and bovine are indeed functionally distinct across the two species, and therefore, are responsible for low production of fully hIgG in our early versions of Tc cattle. The high production levels of fully hIgG with hIgG1 subclass dominancy in a large farm animal species achieved here is an important milestone towards broad therapeutic applications of hpAbs.
authors.affiliation: SAB Biotherapeutics, Inc., Sioux Falls, South Dakota, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsushita
authors.affiliation: Kyowa Hakko Kirin, Co., Ltd., Chiyoda-ku, Tokyo, Japan; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Akiko
authors.initials: A
authors.lastname: Sano
authors.affiliation: SAB Biotherapeutics, Inc., Sioux Falls, South Dakota, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, Utah, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Zhongde
authors.initials: Z
authors.lastname: Wang
authors.affiliation: SAB Biotherapeutics, Inc., Sioux Falls, South Dakota, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Jin-An
authors.initials: JA
authors.lastname: Jiao
authors.affiliation: Trans Ova Genetics, Sioux Center, Iowa, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Poothappillai
authors.initials: P
authors.lastname: Kasinathan
authors.affiliation: SAB Biotherapeutics, Inc., Sioux Falls, South Dakota, United States of America; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Eddie J
authors.initials: EJ
authors.lastname: Sullivan
authors.affiliation: Kyowa Hakko Kirin, Co., Ltd., Chiyoda-ku, Tokyo, Japan; Hematech, Inc., Sioux Falls, South Dakota, United States of America.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Kuroiwa
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D000911:Antibodies, Monoclonal / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D061067:Antibodies, Monoclonal, Humanized / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D000941:Antigens / Q000737:chemistry / Q000276:immunology; D002417:Cattle; D045744:Cell Line, Tumor; D002645:Chickens; D002874:Chromosome Mapping; D022222:Chromosomes, Artificial, Human / Q000737:chemistry / Q000276:immunology*; D055786:Gene Knockout Techniques; D005818:Genetic Engineering; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D008214:Lymphocytes / Q000166:cytology / Q000276:immunology; D054420:Pre-B Cell Receptors / Q000235:genetics / Q000276:immunology*; D013045:Species Specificity
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000941:Antigens; D007074:Immunoglobulin G; D054420:Pre-B Cell Receptors