title: A novel dendritic cell targeting HPV16 E7 synthetic vaccine in combination with PD-L1 blockade elicits therapeutic antitumor immunity in mice.
abstract: Human papilliomavirus (HPV) oncogene E7, essential for the transformation and maintenance of the malignancy of cervical cancer cells, represents an ideal tumor-specific antigen for vaccine development. However, due to the poor immunogenicity of E7 protein, an effective therapeutic E7 vaccine is still lacking. Dendritic cells (DCs) are probably the most potent antigen presenting cells for the induction of cytotoxic T lymphocyte (CTL) response, which is crucial for tumor control. In this study, we tested whether targeting the E7 antigen to DCs in vivo would elicit therapeutic antitumor CTL response. We generated the DEC205-specific single-chain variable fragment (scFv) and E7 long peptide fusion protein [scFv(DEC205)-E7] based on the novel method of protein assembly we recently developed. This fusion protein vaccine demonstrated highly efficient DC-targeting in vivo and elicited much stronger protective CTL response than non-DC-targeting control vaccine in naive mice. Furthermore, the scFv(DEC205)-E7 vaccine showed significant therapeutic antitumor response in TC-1 tumor bearing mice. Importantly, PD-L1 blockade further improved the therapeutic effect of the scFv(DEC205)-E7 vaccine. Thus, the current study suggests an efficient strategy for cervical cancer immunotherapy by combining the DC(DEC205)-targeting E7 vaccine and PD-L1 blockade.
authors.affiliation: Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China; Department of Pathology, University of Texas, Southwestern Medical Center, Dallas, TX, USA.
authors.forename: Zhida
authors.initials: Z
authors.lastname: Liu
authors.affiliation: Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China; University of Chinese Academy of Sciences, Beijing, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Wang
authors.affiliation: Department of Pathology, University of Texas, Southwestern Medical Center , Dallas, TX, USA.
authors.forename: Yang-Xin
authors.initials: YX
authors.lastname: Fu
authors.affiliation: Key Laboratory of Infection and Immunity, Institute of Biophysics, Chinese Academy of Sciences , Beijing, China.
authors.forename: Mingzhao
authors.initials: M
authors.lastname: Zhu
keywords: Cervical cancer; DEC205; HPV E7; PD-1; PD-L1; dendritic cell; therapeutic vaccine