Broadly neutralizing antibodies (BNAb) to HIV-1 primarily target the conserved membrane proximal ectodomain region (MPER) of the viral gpl60 envelope protein. We have studied the HxB2 MPER segment in lipid environments by a combination of nuclear magnetic resonance (NMR), electron paramagnetic resonance (EPR) and surface plasmon resonance (SPR) methodologies. Structural analyses reveal a tilted N-terminal a-helix (aa 664-672) connected via a short hinge (673-674) to a fiat C-terminal helical segment (675-683), collectively forming a metastable L-shaped structure immersed in the membrane. The 4E10 BNAb extracts buried W672 and F673 following initial encounter with the surface embedded MPER while the 2F5 BNAb lifts up residues N-terminal to the hinge region, exposing L669 and W670. BNAb CDRH3 interactions with lipid appear critical for neutralizing activity of both BNAbs. These data have implications for vaccine design and suggest how BNAbs can perturb tryptophan residue associated viral fusion involving the MPER. Here we shall examine how other BNAbs or newly created MPER-binding antibodies induce conformational change around W672 and F673 or elsewhere using several distinct MPER segment sequences. We shall determine whether such structural changes upon antibody binding are linked to viral neutralization. Moreover, specificity and diversity of antibodies arising during natural HIV-1 infection vs. elicited upon vaccination will be compared. Sensitive EPR residue depth and inter-residue distance measurements will allow for relatively rapid screening of detectable changes in MPER conformation. Once identified by EPR, interaction will be followed by detailed NMR analysis. How lipid constituents of the virosome, including cholesterol, affect the membrane-embedded structure of the MPER, or its ability to undergo conformational changes upon antibody binding, will be assessed. In addition, lipid-enveloped nanoparticles as carriers of natively configured MPER segments, including those with a bioresorbable poly (lactide-co-glycolide)(PLGA) core harboring.

Public Health Relevance

Given that globally, to date, 65 million human infections with HIV-1 have been estimated, the development of a vaccine eliciting broadly neutralizing antibodies in normal subjects will be an enormous preventive advance in the fight against AIDS.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Program--Cooperative Agreements (U19)
Project #
Application #
Study Section
Special Emphasis Panel (ZAI1-PTM-A)
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Dana-Farber Cancer Institute
United States
Zip Code
Moyer, Tyson J; Zmolek, Andrew C; Irvine, Darrell J (2016) Beyond antigens and adjuvants: formulating future vaccines. J Clin Invest 126:799-808
Donius, Luke R; Cheng, Yuxing; Choi, Jaewon et al. (2016) Generation of Long-Lived Bone Marrow Plasma Cells Secreting Antibodies Specific for the HIV-1 gp41 Membrane-Proximal External Region in the Absence of Polyreactivity. J Virol 90:8875-90
Song, Likai; Liu, Zhanglong; Kaur, Pavanjeet et al. (2016) Toward increased concentration sensitivity for continuous wave EPR investigations of spin-labeled biological macromolecules at high fields. J Magn Reson 265:188-96
Abbott, Robert K; Thayer, Molly; Labuda, Jasmine et al. (2016) Germinal Center Hypoxia Potentiates Immunoglobulin Class Switch Recombination. J Immunol 197:4014-4020
Hanson, Melissa C; Crespo, Monica P; Abraham, Wuhbet et al. (2015) Nanoparticulate STING agonists are potent lymph node-targeted vaccine adjuvants. J Clin Invest 125:2532-46
Liu, Haipeng; Irvine, Darrell J (2015) Guiding principles in the design of molecular bioconjugates for vaccine applications. Bioconjug Chem 26:791-801
Irvine, Darrell J; Hanson, Melissa C; Rakhra, Kavya et al. (2015) Synthetic Nanoparticles for Vaccines and Immunotherapy. Chem Rev 115:11109-46
Hanson, Melissa C; Abraham, Wuhbet; Crespo, Monica P et al. (2015) Liposomal vaccines incorporating molecular adjuvants and intrastructural T-cell help promote the immunogenicity of HIV membrane-proximal external region peptides. Vaccine 33:861-8
Hatfield, Stephen M; Kjaergaard, Jorgen; Lukashev, Dmitriy et al. (2015) Immunological mechanisms of the antitumor effects of supplemental oxygenation. Sci Transl Med 7:277ra30
Sitkovsky, Michail V; Hatfield, Stephen; Abbott, Robert et al. (2014) Hostile, hypoxia-A2-adenosinergic tumor biology as the next barrier to overcome for tumor immunologists. Cancer Immunol Res 2:598-605

Showing the most recent 10 out of 23 publications