Image_3_Multispecific Antibody Development Platform Based on Human Heavy Chain Antibodies.pdf Starlynn C. Clarke Biao Ma Nathan D. Trinklein Ute Schellenberger Michael J. Osborn Laure-Hélène Ouisse Andrew Boudreau Laura M. Davison Katherine E. Harris Harshad S. Ugamraj Aarti Balasubramani Kevin H. Dang Brett Jorgensen Heather Anne N. Ogana Duy T. Pham Payal P. Pratap Preethi Sankaran Ignacio Anegon Wim C. van Schooten Marianne Brüggemann Roland Buelow Shelley Force Aldred 10.3389/fimmu.2018.03037.s004 https://frontiersin.figshare.com/articles/figure/Image_3_Multispecific_Antibody_Development_Platform_Based_on_Human_Heavy_Chain_Antibodies_pdf/7552376 <p>Heavy chain-only antibodies (HCAbs) do not associate with light chains and their V<sub>H</sub> regions are functional as single domains, forming the smallest active antibody fragment. These V<sub>H</sub> regions are ideal building blocks for a variety of antibody-based biologics because they tolerate fusion to other molecules and may also be attached in series to construct multispecific antibodies without the need for protein engineering to ensure proper heavy and light chain pairing. Production of human HCAbs has been impeded by the fact that natural human V<sub>H</sub> regions require light chain association and display poor biophysical characteristics when expressed in the absence of light chains. Here, we present an innovative platform for the rapid development of diverse sets of human HCAbs that have been selected in vivo. Our unique approach combines antibody repertoire analysis with immunization of transgenic rats, called UniRats, that produce chimeric HCAbs with fully human V<sub>H</sub> domains in response to an antigen challenge. UniRats express HCAbs from large transgenic loci representing the entire productive human heavy chain V(D)J repertoire, mount robust immune responses to a wide array of antigens, exhibit diverse V gene usage and generate large panels of stable, high affinity, antigen-specific molecules.</p> 2019-01-07 04:15:01 heavy chain antibodies VH domains domain antibodies antibody discovery platform next-generation sequencing repertoire sequencing transgenic rats B cell development