Introduction of the YTE mutation into the non-immunogenic HIV bnAb PGT121 induces anti-drug antibodies in macaques
PublisherPublic Library of Science
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AbstractRecombinant antibodies play increasingly important roles as immunotherapeutic treatments for human cancers as well as inflammatory and infectious diseases and have revolutionized their management. In addition, their therapeutic potential may be enhanced by the introduction of defined mutations in the crystallizable fragment (Fc) domains eg YTE (M252Y/ S254T/T256E) and LS (M428L/N434S), as a consequence of increased half-lives and prolonged duration of protection. However, the functional properties of any biologic may be compromised by unanticipated immunogenicity in humans, rendering them ineffective. Several potent broadly neutralizing HIV monoclonal antibodies (bnAbs) have been identified that protect against SHIV challenge in macaque models and reduce HIV viremia in HIV-infected individuals. In the present study, the pharmacokinetics and immunogenicity of one or more 5mg/kg subcutaneous (SC) injections in naive macaques of the HIV bnAb PGT121 and its PGT121-YTE mutant, both produced in plants, have been compared towards prolonging efficacy. Induction of anti-drug/anti-idiotypic antibodies (ADA, anti-id) has been monitored using both binding ELISAs and more functional inhibition of virus neutralization (ID50) assays. Timing of the anti-Id responses and their impact on pharmacokinetic profiles (clearance) and efficacy (protection) have also been assessed. The results indicate that ADA induction in naive macaques may result both from injection of the previously non-immunogenic PGT121 into pre-primed animals and also by the introduction of the YTE mutation. Binding ADA antibody levels, induced in 7/10 macaques within two weeks of a first or second PGT121-YTE injection, were closely associated with both reduced pharmacokinetic profiles and loss of protection. However no correlation was observed with inhibitory ADA activity. These studies provide insights into both the structural features of bnAb and the immune status of the host which may contribute to the development of ADA in macaques and describe possible YTE-mediated changes in structure/orientation of HIV bnAbs that trigger such responses.
SponsorsYR received funding from National Institutes of Health, National Institute of Allergy and Infectious Diseases (NIAID) grant #R44AI081621, which provided support in the form of salaries for authors YR, XJ LU, LM and JL but had no additional role in the study design, data collection and analysis, decision to publish or preparation of the manuscript. DM and CL were funded in part by NIH/NIAID NHP Humoral Immunology Laboratory Contract #HHSN27201100016C.
Rights/TermsThis is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85061928378&doi=10.1371%2fjournal.pone.0212649&partnerID=40&md5=0d21df5d0a441672c88d505116317101; http://hdl.handle.net/10713/8643