Repertoire characterization and validation of gB-specific human IgGs directly cloned from humanized mice vaccinated with dendritic cells and protected against HCMV

PLoS Pathog. 2020 Jul 15;16(7):e1008560. doi: 10.1371/journal.ppat.1008560. eCollection 2020 Jul.

Abstract

Human cytomegalovirus (HCMV) causes serious complications to immune compromised hosts. Dendritic cells (iDCgB) expressing granulocyte-macrophage colony-stimulating factor, interferon-alpha and HCMV-gB were developed to promote de novo antiviral adaptive responses. Mice reconstituted with a human immune system (HIS) were immunized with iDCgB and challenged with HCMV, resulting into 93% protection. Immunization stimulated the expansion of functional effector memory CD8+ and CD4+ T cells recognizing gB. Machine learning analyses confirmed bone marrow T/CD4+, liver B/IgA+ and spleen B/IgG+ cells as predictive biomarkers of immunization (≈87% accuracy). CD8+ and CD4+ T cell responses against gB were validated. Splenic gB-binding IgM-/IgG+ B cells were sorted and analyzed at a single cell level. iDCgB immunizations elicited human-like IgG responses with a broad usage of various IgG heavy chain V gene segments harboring variable levels of somatic hypermutation. From this search, two gB-binding human monoclonal IgGs were generated that neutralized HCMV infection in vitro. Passive immunization with these antibodies provided proof-of-concept evidence of protection against HCMV infection. This HIS/HCMV in vivo model system supported the validation of novel active and passive immune therapies for future clinical translation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / pharmacology
  • Antibodies, Neutralizing / immunology
  • Antibodies, Neutralizing / pharmacology
  • Antibodies, Viral / immunology*
  • Antigens, Viral / immunology
  • Cytomegalovirus / immunology
  • Cytomegalovirus Infections / immunology*
  • Cytomegalovirus Vaccines / immunology*
  • Dendritic Cells / immunology
  • Disease Models, Animal
  • Humans
  • Immunization, Passive*
  • Immunoglobulin G / immunology*
  • Immunoglobulin G / pharmacology
  • Mice

Substances

  • Antibodies, Monoclonal
  • Antibodies, Neutralizing
  • Antibodies, Viral
  • Antigens, Viral
  • Cytomegalovirus Vaccines
  • Immunoglobulin G

Grants and funding

R.S./S.T./V.V./H.O. Hannover: This work was financed by grants of the German Center for Infections Research (DZIF-TTU07.803 and DZIF-TTU07.805 to R.S.), by a research collaboration grant of “The Jackson Laboratory” and by the German Research Council (DFG/SFB738 Project A6 to R.S. and MM; DFG/REBIRTH Unit 6.4 to R.S.). S.T. received a RegSci Ph.D. fellowship, H.O. received a DZIF-Strucmed fellowship and V.V. received a DAAD/ZIB Ph.D. fellowship. F.K./C.K./ Univ. Cologne: This work was funded by grants from the German Center for Infection Research (DZIF, F.K.), the German Research Foundation (CRC 1279, F.K.; CRC 1310, C.K. and F.K.; Heisenberg-Program KL2389/2-1, F.K.) and the European Research Council (ERC-StG639961, F.K.). M.M.-H./ S.K./ Braunschweig: S.K. was supported by the German Federal Ministry of Education and Research (BMBF) for the eMED project SYSIMIT and by the Helmholtz-Gemeinschaft, Zukunftsthema “Immunology and Inflammation” (ZT-0027). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.