Molecular Evolution of Broadly Neutralizing Llama Antibodies to the CD4-Binding Site of HIV-1

PLoS Pathogens

Michael S. Seaman¹  Vanina Grippo²  Luke Granger³  Alexander Kliche⁴  Nika M. Strokappe⁵  Theo Verrips⁵  Lucy Rutten⁵  Paul Kellam⁶  Rachael Bashford-Rogers⁶  Willie Koh⁷  Ariberto Fassati⁷  Gillian Dekkers⁷  Laura E. McCoy⁷  Dan Frampton⁷  Ian Anderson⁷  Robin A. Weiss⁷ 

[1] Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, United States of America;Centro de Virología Animal, Instituto de Ciencia y Tecnología Dr. César Milstein, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina;Department of Infectious Diseases, King's College London School of Medicine, Guy's Hospital, London, United Kingdom;Institute of Medical Microbiology, University of Regensburg, Regensburg, Germany;QVQ B.V., Utrecht, The Netherlands;Wellcome Trust Sanger Institute, Cambridge, United Kingdom;Wohl Virion Centre and Medical Research Council (MRC) Centre for Medical Molecular Virology, Division of Infection and Immunity, University College London, London, United Kingdom

关键词: Antibodies;    HIV;    Antigens;    HIV-1;    Enzyme-linked immunoassays;    Cloning;    Sequence alignment;    Immune response;   

DOI  :  10.1371/journal.ppat.1004552

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

To date, no immunization of humans or animals has elicited broadly neutralizing sera able to prevent HIV-1 transmission; however, elicitation of broad and potent heavy chain only antibodies (HCAb) has previously been reported in llamas. In this study, the anti-HIV immune responses in immunized llamas were studied via deep sequencing analysis using broadly neutralizing monoclonal HCAbs as a guides. Distinct neutralizing antibody lineages were identified in each animal, including two defined by novel antibodies (as variable regions called VHH) identified by robotic screening of over 6000 clones. The combined application of five VHH against viruses from clades A, B, C and CRF_AG resulted in neutralization as potent as any of the VHH individually and a predicted 100% coverage with a median IC50 of 0.17 µg/ml for the panel of 60 viruses tested. Molecular analysis of the VHH repertoires of two sets of immunized animals showed that each neutralizing lineage was only observed following immunization, demonstrating that they were elicited de novo. Our results show that immunization can induce potent and broadly neutralizing antibodies in llamas with features similar to human antibodies and provide a framework to analyze the effectiveness of immunization protocols.

【 授权许可】

CC BY