Peptide mimic for influenza vaccination using nonnatural combinatorial chemistry
John J. Miles, … , David A. Price, Andrew K. Sewell
John J. Miles, … , David A. Price, Andrew K. Sewell
Published March 12, 2018
Citation Information: J Clin Invest. 2018;128(4):1569-1580. https://doi.org/10.1172/JCI91512.
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Research Article Immunology Infectious disease

Peptide mimic for influenza vaccination using nonnatural combinatorial chemistry

Abstract

Polypeptide vaccines effectively activate human T cells but suffer from poor biological stability, which confines both transport logistics and in vivo therapeutic activity. Synthetic biology has the potential to address these limitations through the generation of highly stable antigenic “mimics” using subunits that do not exist in the natural world. We developed a platform based on D–amino acid combinatorial chemistry and used this platform to reverse engineer a fully artificial CD8+ T cell agonist that mirrored the immunogenicity profile of a native epitope blueprint from influenza virus. This nonnatural peptide was highly stable in human serum and gastric acid, reflecting an intrinsic resistance to physical and enzymatic degradation. In vitro, the synthetic agonist stimulated and expanded an archetypal repertoire of polyfunctional human influenza virus–specific CD8+ T cells. In vivo, specific responses were elicited in naive humanized mice by subcutaneous vaccination, conferring protection from subsequent lethal influenza challenge. Moreover, the synthetic agonist was immunogenic after oral administration. This proof-of-concept study highlights the power of synthetic biology to expand the horizons of vaccine design and therapeutic delivery.

Authors

John J. Miles, Mai Ping Tan, Garry Dolton, Emily S.J. Edwards, Sarah A.E. Galloway, Bruno Laugel, Mathew Clement, Julia Makinde, Kristin Ladell, Katherine K. Matthews, Thomas S. Watkins, Katie Tungatt, Yide Wong, Han Siean Lee, Richard J. Clark, Johanne M. Pentier, Meriem Attaf, Anya Lissina, Ann Ager, Awen Gallimore, Pierre J. Rizkallah, Stephanie Gras, Jamie Rossjohn, Scott R. Burrows, David K. Cole, David A. Price, Andrew K. Sewell

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Figure 2

A fully synthetic agonist designed from CPL scan data is recognized by multiple influenza-specific clones and is highly resistant to human proteases and gastric acid.

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A fully synthetic agonist designed from CPL scan data is recognized by m...
(A) Clone ALF3 was incubated with C1R-A2 target cells pulsed with the indicated concentrations of D–amino acid candidate agonists predicted from the D–amino acid CPL scan (Figure 1). MIP-1β release in the supernatants was quantified by ELISA. Errors from 2 replicates depict SEM. (B) ALF3 was incubated overnight with the indicated concentrations of GILGFVFTL and gppqwnnpp. Errors from 2 replicates depict SEM. (C) Chromium release cytotoxicity assay using ALF3 and CIR-A2 targets incubated with gppqwnnpp and GILGFVFTL peptides at the concentrations shown. Errors from 2 replicates depict SEM. (D) As in A but including GILGFVFTL with clones GD, SG11, and SG25. ALF3 was also included for comparison. Errors from 2 replicates depict SEM. (E) The GILGFVFTL or gppqwnnpp peptides were added to human serum or MilliQ water and sampled in triplicate at the indicated time points. Ion peak signals that identified each peptide were quantified using LCMS. Stability was calculated as the area percentage of each serum-treated or water-treated ion peak relative to the same ion peak at 0 minutes. (F) GILGFVFTL and gppqwnnpp were added to simulated gastric acid (NaCl, pepsin, and HCl; pH 1.2) and sampled in triplicate at the indicated time points. Ion peak signals that identified each agonist were quantified using LCMS. Stability was calculated as the area percentage of each gastric acid–treated ion peak relative to the same ion peak at 0 minutes. Recovery rates of gppqwnnpp in human serum and gastric acid were significantly higher compared with GILGFVFTL at all time points beyond 0 minutes (P < 0.00001). Errors from 3 replicates depict SEM. In some panels, error bars are smaller than the plot symbols.