Enhanced Cytotoxic CD8 T Cell Priming Using Dendritic
Cell-Expressing Human Papillomavirus-16 E6/E7-p16INK4 Fusion Protein with
Sequenced Anti-Programmed Death-1.
Garcia-Bates TM1, Kim E2, Concha-Benavente F3, Trivedi S4,
Mailliard RB5, Gambotto A2, Ferris RL6.
1. Department of Otolaryngology, University of Pittsburgh,
Pittsburgh, PA 15232; Department of Infectious Diseases and Microbiology,
Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
15232;
2. Department of Surgery, University of Pittsburgh,
Pittsburgh, PA 15232;
3. Department of Immunology, University of Pittsburgh,
Pittsburgh, PA 15232; and.
4. Department of Otolaryngology, University of Pittsburgh,
Pittsburgh, PA 15232;
5. Department of Infectious Diseases and Microbiology,
Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA
15232;
6. Department of Otolaryngology, University of Pittsburgh,
Pittsburgh, PA 15232; Department of Immunology, University of Pittsburgh,
Pittsburgh, PA 15232; and Cancer Immunology Program, University of Pittsburgh
Cancer Institute, Pittsburgh, PA 15213 ferrisrl@upmc.edu.
Abstract
The incidence of human
papillomavirus (HPV)-related head and neck squamous cell carcinoma has
increased in recent decades, though HPV prevention vaccines may reduce this
rise in the future. HPV-related cancers express the viral oncoproteins E6 and
E7. The latter inactivates the tumor suppressor protein retinoblastoma (Rb),
which leads to the overexpression of p16(INK4) protein, providing unique Ags
for therapeutic HPV-specific cancer vaccination. We developed potential adenoviral
vaccines that express a fusion protein of HPV-16 E6 and E7 (Ad.E6E7) alone or
fused with p16 (Ad.E6E7p16) and also encoding an anti-programmed death (PD)-1
Ab. Human monocyte-derived dendritic cells (DC) transduced with Ad.E6E7 or
Ad.E6E7p16 with or without Ad.αPD1 were used to activate autologous CD8 CTL in
vitro. CTL responses were tested against naturally HPV-infected head and neck
squamous cell carcinoma cells using IFN-γ ELISPOT and [(51)Cr]release assay.
Surprisingly, stimulation and antitumor activity of CTL were increased after
incubation with Ad.E6E7p16-transduced DC (DC.E6E7p16) compared with Ad.E6E7
(DC.E6E7), a result that may be due to an effect of p16 on cyclin-dependent
kinase 4 levels and IL-12 secretion by DC. Moreover, the beneficial effect was
most prominent when anti-PD-1 was introduced during the second round of
stimulation (after initial priming). These data suggest that careful sequencing
of Ad.E6E7.p16 with Ad.αPD1 could improve antitumor immunity against
HPV-related tumors and that p16 may enhance the immunogenicity of DC, through
cyclin-dependent pathways, Th1 cytokine secretion, and by adding a nonviral Ag
highly overexpressed in HPV-induced cancers.
J Immunol. 2016 Mar 15;196(6):2870-8. doi:
10.4049/jimmunol.1502027. Epub 2016 Feb 5.
Md. PhD. Fernando Concha. Ex-miembro del GII
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