Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2023 Aug 9;31(8):1288-1300.e6.
doi: 10.1016/j.chom.2023.07.002. Epub 2023 Jul 28.

Potent cross-neutralization of respiratory syncytial virus and human metapneumovirus through a structurally conserved antibody recognition mode

Affiliations

Potent cross-neutralization of respiratory syncytial virus and human metapneumovirus through a structurally conserved antibody recognition mode

Xiaolin Wen et al. Cell Host Microbe. .

Abstract

Respiratory syncytial virus (RSV) and human metapneumovirus (hMPV) infections pose a significant health burden. Using pre-fusion conformation fusion (F) proteins, we isolated a panel of anti-F antibodies from a human donor. One antibody (RSV-199) potently cross-neutralized 8 RSV and hMPV strains by recognizing antigenic site III, which is partially conserved in RSV and hMPV F. Next, we determined the cryoelectron microscopy (cryo-EM) structures of RSV-199 bound to RSV F trimers, hMPV F monomers, and an unexpected dimeric form of hMPV F. These structures revealed how RSV-199 engages both RSV and hMPV F proteins through conserved interactions of the antibody heavy-chain variable region and how variability within heavy-chain complementarity-determining region 3 (HCDR3) can be accommodated at the F protein interface in site-III-directed antibodies. Furthermore, RSV-199 offered enhanced protection against RSV A and B strains and hMPV in cotton rats. These findings highlight the mechanisms of broad neutralization and therapeutic potential of RSV-199.

Keywords: adaptive immunity; antibodies; broad neutralization; human; human metapneumovirus; monoclonal; neutralizing; protective in vivo; respiratory syncytial virus.

PubMed Disclaimer

Conflict of interest statement

Declaration of interests J.E.C. has served as a consultant for Luna Labs USA, Merck Sharp & Dohme Corporation, Emergent Biosolutions, GlaxoSmithKline, and BTG International Inc. He is a member of the Scientific Advisory Board of Meissa Vaccines, a former member of the Scientific Advisory Board of Gigagen (Grifols), and founder of IDBiologics. The laboratory of J.E.C. received unrelated sponsored research agreements from AstraZeneca, Takeda, and IDBiologics during the conduct of the study. T.S.J. has served as a consultant for Pfizer. Vanderbilt University has applied for patents for some of the antibodies in this paper.

Figures

Figure 1.
Figure 1.
A. Neutralization curves for RSV-reactive or control antibodies against diverse strains of RSV. B. Neutralizing activity of RSV-, hMPV-, or RSV- and hMPV-reactive mAbs against diverse strains of RSV and hMPV.
Figure 2.
Figure 2.. Two human mAbs strongly bind to both RSV and hMPV F proteins and compete for binding.
(A) ELISA binding of RSV-199, MEDI8897, MPE8, RSV-90 or rDENV-2D22 to hMPV prefusion F protein, RSV strain A2 pre-fusion F protein (SC-TM) or RSV strain A2 post-fusion F protein. Data are mean ± standard deviations (S.D.) of technical triplicates from a representative experiment repeated twice. (B) Competition-binding of monoclonal antibodies reactive with hMPV prefusion F protein. Values in squares are the percent binding of the monoclonal antibody in the presence of the competing monoclonal antibody relative to a mock-competition control. Black squares indicate full competition (<33% relative binding); grey squares indicate intermediate competition; white squares indicate no competition (>67% relative binding).
Figure 3.
Figure 3.. Structural insights into anti-F antibody epitopes and hMPV F dimerization.
Cryo-EM structures of complexes of (A) monomeric hMPV F+ Fab RSV-199, (B) dimeric hMPV F + Fab RSV-199, (C) hMPV F + Fab hMPV-4I3 and (D) hMPV F + Fab hMPV-2J6. The proximity of 2J6 to adjacent F subunits in a modeled trimer is shown below. (E) docking of hMPV-4I3, hMPV-2J6 and RSV-199 Fabs onto a model of the hMPV F trimer. (F, G) hMPV F dimer observed in complexes with Fab RSV-199; one protomer is colored grey the other is colored red. Residues surrounding the furin cleavage site at the dimer interface are colored in blue. (H) Asymmetric packing of residues 92 to 112 comprising the furin cleavage site and N-terminal residues of the fusion peptide into the neighboring F protomer.
Figure 4.
Figure 4.. Structural basis for cross-neutralization of hMPV and RSV by RSV-199.
(A) Cryo-EM structure of RSV F protein + mAb RSV-199 trimers. (B) RSV-199 epitope on the RSV F protein surface. Conserved residue surfaces are shown in blue. (C) RSV-199 epitope on the hMPV F protein surface. Conserved residue surfaces are shown in blue. (D) Superposition of single protomer complexes of hMPV F and RSV F RSV-199 complexes. (E) Interactions of LCDR1 and LCDR3 at the RSV or hMPV F interface. (F) Interactions of the antibody HCDR3 at the RSV or hMPV F interface. (G) Interactions of the antibody HCDR1 and HCDR2 at the RSV or hMPV F interface. (VH, VL indicates heavy chain variable region and light chain variable region; DI and DII indicate domain-I and domain-II)
Figure 5.
Figure 5.. Accommodation of the antibody HCDR3 sequence for structural diversity in F protein antigenic site III.
(A, B) Superposition of RSV-199, MPE8 and ADI19425 Fabs on an RSV F trimer. (C) The heavy chain variable region of RSV-199 adopts a rotated pose compared to that of MPE8 and ADI19425, pivoting about conserved interactions mediated by the HCDR1 and HCDR2 loops. HCDR3 loops adopt distinct structures and interactions to accommodate their different lengths and sequences. (D) The light chain variable region of RSV-199 shifts away from the RSV F trimer surface relative to MPE8 and ADI19425 Fabs. (E) HCDR3 sequence and length diversity of RSV-199, MPE8 and ADI19425 Fabs. (F) Y91/93 and Y31/33, which are important for affinity of binding to F protein, adopt similar positions in RSV-199 despite shifts in the Fab pose on F.
Figure 6.
Figure 6.. In vivo efficacy of RSV-199 in cotton rats against challenge with RSV subgroup A or B and hMPV A2 virus strains.
Cotton rats were treated with the indicated concentrations (mg/kg) of mAb, and then inoculated intranasally with the RSV strain indicated. Viral burden at 4 dpi for RSV and 5 dpi for hMPV in the lungs, measured by plaque assay; comparisons were made using a one-way ANOVA with Dunn’s post hoc test (n = 5 cotton rats per group). Animals with an “X” in the circle indicates below detectable levels of serum human IgG.

Similar articles

Cited by

References

    1. Collins PL, and Karron RA (2013). Respiratory syncytial virus and metapneumovirus. In Fields Virology, Knipe DM, and Howley PM, eds. (Wolters Kluwer Health Adis (ESP)).
    1. Boivin G, De Serres G, Cote S, Gilca R, Abed Y, Rochette L, Bergeron MG, and Dery P (2003). Human metapneumovirus infections in hospitalized children. Emerg Infect Dis 9, 634–640. 10.3201/eid0906.030017. - DOI - PMC - PubMed
    1. Freymouth F, Vabret A, Legrand L, Eterradossi N, Lafay-Delaire F, Brouard J, and Guillois B (2003). Presence of the new human metapneumovirus in French children with bronchiolitis. Pediatr Infect Dis J 22, 92–94. 10.1097/00006454-200301000-00024. - DOI - PubMed
    1. Mazur NI, Terstappen J, Baral R, Bardaji A, Beutels P, Buchholz UJ, Cohen C, Crowe JE Jr., Cutland CL, Eckert L, et al. (2022). Respiratory syncytial virus prevention within reach: the vaccine and monoclonal antibody landscape. Lancet Infect Dis. 10.1016/S1473-3099(22)00291-2. - DOI - PMC - PubMed
    1. Crank MC, Ruckwardt TJ, Chen M, Morabito KM, Phung E, Costner PJ, Holman LA, Hickman SP, Berkowitz NM, Gordon IJ, et al. (2019). A proof of concept for structure-based vaccine design targeting RSV in humans. Science 365, 505–509. 10.1126/science.aav9033. - DOI - PubMed

LinkOut - more resources