Paramyxoviruses are enveloped viruses that enter cells by fusing directly with the cell membrane. During entry the two viral surface glycoproteins HN (the receptor-binding molecule) and F (the viral fusion protein) cooperate in a highly specific way to mediate fusion upon receptor binding. However, during virus replication and assembly in the cytoplasm the fusion process is silent, and until an incoming virus meets its target cell, the fusion machine is inactive. How is the fusion process coordinated in time and place? To understand these mechanisms and elucidate how paramyxoviruses enter cells, we study the human parainfluenza virus (HPIV), an important cause of respiratory disease in children. Our results have uncovered fundamental roles of the receptor binding protein in paramyxovirus fusion, and principles of coordinated interaction between the glycoproteins during the viral life cycle. We have developed new, interdisciplinary tools to dissect the complex process whereby paramyxoviruses control entry, and central questions in the field can now be addressed.
Specific Aim 1. Mechanisms by which the diverse functions of the paramyxovirus receptor-binding molecule are coordinated. How does attachment by the primary receptor binding site of HN translate into the F-triggering that is promoted by HN's second binding/triggering site? Mutations at HN's two functional binding sites will be used to study how HN works to trigger F. These experiments will define how the activities of HN are coordinated for HPIV, and how distinct strategies in other paramyxoviruses accomplish the same ends.
Specific Aim 2. How the receptor-binding molecule and the fusion molecule communicate during fusion and entry. What is the nature of the communication between HN and F during fusion and entry, and how is this communication regulated? A series of innovative strategies will test the hypothesis that specific HN-F interactions regulate F-activation. These experiments will for the first time define the biologically relevant dialog between the molecules that comprise the paramyxovirus fusion machine.
Specific Aim 3. Regulation of fusion during the paramyxoviral life cycle in airway cells. Correct timing of F-activation is essential for entry;for infection, triggering must occur only when F is in contact with the target cell membrane. How are the diverse functions of these proteins regulated during the viral life cycle, and can we subvert this regulation as a strategy for antivirals? We will test the hypothesis that dysregulation of F-triggering precludes successful infection, in a system that represents human lung epithelium. We will determine whether compounds can prematurely trigger F, and whether this may prevent airway infection, providing a new antiviral strategy. The underlying principles revealed here will offer insights into complex molecular machines that require allosteric activation. The results will likely apply to other pathogens that must trigger these key entry activities only at a specific time and place to initiate infection.

Public Health Relevance

This research proposal will lead to a better understanding of how paramyxoviruses enter human cells to initiate infection. Newly identified mechanisms involved in the entry process could serve as potential new targets for antivirals to treat or prevent human respiratory diseases.

National Institute of Health (NIH)
National Institute of Allergy and Infectious Diseases (NIAID)
Research Project (R01)
Project #
Application #
Study Section
Virology - B Study Section (VIRB)
Program Officer
Kim, Sonnie
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Weill Medical College of Cornell University
Schools of Medicine
New York
United States
Zip Code
Iketani, Sho; Shean, Ryan C; Ferren, Marion et al. (2018) Viral Entry Properties Required for Fitness in Humans Are Lost through Rapid Genomic Change during Viral Isolation. MBio 9:
Mathieu, Cyrille; Porotto, Matteo; Figueira, Tiago N et al. (2018) Fusion Inhibitory Lipopeptides Engineered for Prophylaxis of Nipah Virus in Primates. J Infect Dis 218:218-227
Figueira, T N; Palermo, L M; Veiga, A S et al. (2017) In Vivo Efficacy of Measles Virus Fusion Protein-Derived Peptides Is Modulated by the Properties of Self-Assembly and Membrane Residence. J Virol 91:
Chen, Ya-Wen; Huang, Sarah Xuelian; de Carvalho, Ana Luisa Rodrigues Toste et al. (2017) A three-dimensional model of human lung development and disease from pluripotent stem cells. Nat Cell Biol 19:542-549
Figueira, Tiago N; Freire, João M; Cunha-Santos, Catarina et al. (2017) Quantitative analysis of molecular partition towards lipid membranes using surface plasmon resonance. Sci Rep 7:45647
Augusto, Marcelo T; Hollmann, Axel; Porotto, Matteo et al. (2017) Antiviral Lipopeptide-Cell Membrane Interaction Is Influenced by PEG Linker Length. Molecules 22:
Mathieu, Cyrille; Augusto, Marcelo T; Niewiesk, Stefan et al. (2017) Broad spectrum antiviral activity for paramyxoviruses is modulated by biophysical properties of fusion inhibitory peptides. Sci Rep 7:43610
Palermo, Laura M; Uppal, Manik; Skrabanek, Lucy et al. (2016) Features of Circulating Parainfluenza Virus Required for Growth in Human Airway. MBio 7:e00235
Mathieu, C; Huey, D; Jurgens, E et al. (2015) Prevention of measles virus infection by intranasal delivery of fusion inhibitor peptides. J Virol 89:1143-55
Gui, Long; Jurgens, Eric M; Ebner, Jamie L et al. (2015) Electron tomography imaging of surface glycoproteins on human parainfluenza virus 3: association of receptor binding and fusion proteins before receptor engagement. MBio 6:e02393-14

Showing the most recent 10 out of 32 publications