PMID- 28902916
OWN - NLM
STAT- MEDLINE
DCOM- 20171020
LR  - 20180203
IS  - 1553-7374 (Electronic)
IS  - 1553-7366 (Linking)
VI  - 13
IP  - 9
DP  - 2017 Sep
TI  - Targeted N-glycan deletion at the receptor-binding site retains HIV Env NFL
      trimer integrity and accelerates the elicited antibody response.
PG  - e1006614
LID - 10.1371/journal.ppat.1006614 [doi]
AB  - Extensive shielding by N-glycans on the surface of the HIV envelope glycoproteins
      (Env) restricts B cell recognition of conserved neutralizing determinants.
      Elicitation of broadly neutralizing antibodies (bNAbs) in selected HIV-infected
      individuals reveals that Abs capable of penetrating the glycan shield can be
      generated by the B cell repertoire. Accordingly, we sought to determine if
      targeted N-glycan deletion might alter antibody responses to Env. We focused on
      the conserved CD4 binding site (CD4bs) since this is a known neutralizing
      determinant that is devoid of glycosylation to allow CD4 receptor engagement, but
      is ringed by surrounding N-glycans. We selectively deleted potential N-glycan
      sites (PNGS) proximal to the CD4bs on well-ordered clade C 16055 native flexibly 
      linked (NFL) trimers to potentially increase recognition by naive B cells in
      vivo. We generated glycan-deleted trimer variants that maintained native-like
      conformation and stability. Using a panel of CD4bs-directed bNAbs, we
      demonstrated improved accessibility of the CD4bs on the N-glycan-deleted trimer
      variants. We showed that pseudoviruses lacking these Env PNGSs were more
      sensitive to neutralization by CD4bs-specific bNAbs but remained resistant to
      non-neutralizing mAbs. We performed rabbit immunogenicity experiments using two
      approaches comparing glycan-deleted to fully glycosylated NFL trimers. The first 
      was to delete 4 PNGS sites and then boost with fully glycosylated Env; the second
      was to delete 4 sites and gradually re-introduce these N-glycans in subsequent
      boosts. We demonstrated that the 16055 PNGS-deleted trimers more rapidly elicited
      serum antibodies that more potently neutralized the CD4bs-proximal-PNGS-deleted
      viruses in a statistically significant manner and strongly trended towards
      increased neutralization of fully glycosylated autologous virus. This approach
      elicited serum IgG capable of cross-neutralizing selected tier 2 viruses lacking 
      N-glycans at residue N276 (natural or engineered), indicating that PNGS deletion 
      of well-ordered trimers is a promising strategy to prime B cell responses to this
      conserved neutralizing determinant.
FAU - Dubrovskaya, Viktoriya
AU  - Dubrovskaya V
AD  - Department of Immunology and Microbiology, The Scripps Research Institute, La
      Jolla, California, United States of America.
FAU - Guenaga, Javier
AU  - Guenaga J
AD  - IAVI Neutralizing Center at TSRI, Department of Research and Development,
      International AIDS Vaccine Initiative, La Jolla, California, United States of
      America.
FAU - de Val, Natalia
AU  - de Val N
AD  - Department of Integrative Structural and Computational Biology, The Scripps
      Research Institute, La Jolla, California, United States of America.
FAU - Wilson, Richard
AU  - Wilson R
AD  - IAVI Neutralizing Center at TSRI, Department of Research and Development,
      International AIDS Vaccine Initiative, La Jolla, California, United States of
      America.
FAU - Feng, Yu
AU  - Feng Y
AUID- ORCID: http://orcid.org/0000-0003-1564-4098
AD  - IAVI Neutralizing Center at TSRI, Department of Research and Development,
      International AIDS Vaccine Initiative, La Jolla, California, United States of
      America.
FAU - Movsesyan, Arlette
AU  - Movsesyan A
AUID- ORCID: http://orcid.org/0000-0001-5601-4100
AD  - Department of Immunology and Microbiology, The Scripps Research Institute, La
      Jolla, California, United States of America.
FAU - Karlsson Hedestam, Gunilla B
AU  - Karlsson Hedestam GB
AD  - Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet,
      Stockholm, Sweden.
FAU - Ward, Andrew B
AU  - Ward AB
AD  - IAVI Neutralizing Center at TSRI, Department of Research and Development,
      International AIDS Vaccine Initiative, La Jolla, California, United States of
      America.
AD  - Department of Integrative Structural and Computational Biology, The Scripps
      Research Institute, La Jolla, California, United States of America.
AD  - The Scripps CHAVI-ID, The Scripps Research Institute, La Jolla, California,
      United States of America.
FAU - Wyatt, Richard T
AU  - Wyatt RT
AUID- ORCID: http://orcid.org/0000-0001-7085-1351
AD  - Department of Immunology and Microbiology, The Scripps Research Institute, La
      Jolla, California, United States of America.
AD  - IAVI Neutralizing Center at TSRI, Department of Research and Development,
      International AIDS Vaccine Initiative, La Jolla, California, United States of
      America.
AD  - The Scripps CHAVI-ID, The Scripps Research Institute, La Jolla, California,
      United States of America.
LA  - eng
GR  - P01 AI104722/AI/NIAID NIH HHS/United States
PT  - Journal Article
DEP - 20170913
PL  - United States
TA  - PLoS Pathog
JT  - PLoS pathogens
JID - 101238921
RN  - 0 (Antibodies, Neutralizing)
RN  - 0 (CD4 Antigens)
RN  - 0 (Epitopes, B-Lymphocyte)
RN  - 0 (HIV Antibodies)
RN  - 0 (Polysaccharides)
RN  - 0 (env Gene Products, Human Immunodeficiency Virus)
SB  - IM
MH  - Animals
MH  - Antibodies, Neutralizing/*immunology
MH  - B-Lymphocytes/immunology
MH  - CD4 Antigens/immunology
MH  - Enzyme-Linked Immunosorbent Assay
MH  - Epitopes, B-Lymphocyte/immunology
MH  - Female
MH  - HIV Antibodies/*immunology
MH  - HIV-1/immunology
MH  - Imaging, Three-Dimensional
MH  - Lymphocyte Activation/immunology
MH  - Microscopy, Electron
MH  - Mutagenesis, Site-Directed
MH  - Polysaccharides/*immunology
MH  - Rabbits
MH  - env Gene Products, Human Immunodeficiency Virus/*immunology
PMC - PMC5640423
EDAT- 2017/09/14 06:00
MHDA- 2017/10/21 06:00
CRDT- 2017/09/14 06:00
PHST- 2017/06/12 00:00 [received]
PHST- 2017/08/29 00:00 [accepted]
PHST- 2017/10/13 00:00 [revised]
PHST- 2017/09/14 06:00 [pubmed]
PHST- 2017/10/21 06:00 [medline]
PHST- 2017/09/14 06:00 [entrez]
AID - 10.1371/journal.ppat.1006614 [doi]
AID - PPATHOGENS-D-17-01245 [pii]
PST - epublish
SO  - PLoS Pathog. 2017 Sep 13;13(9):e1006614. doi: 10.1371/journal.ppat.1006614.
      eCollection 2017 Sep.