DNA prime/MVTT boost regimen with HIV-1 mosaic Gag enhances the potency of antigen-specific immune responses

Wan Liu, Yik Chun Wong, Samantha M.Y. Chen, Jiansong Tang, Haibo Wang, Ka Loon Allen Cheung, Zhiwei Chen*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

8 Citations (Scopus)


HIV-1 diversity and latent reservoir are the major challenges for the development of an effective AIDS vaccine. It is well indicated that Gag-specific CD8+ T cells serve as the dominant host immune surveillance for HIV-1 control, but it still remains a challenge for vaccine design to induce broader and stronger cytotoxic T cell immunity against the virus. Genetic variation of the HIV-1 gag gene across different clades is one of the reasons for the reduction of antigenic epitope coverage. Here, we report an immunization strategy with heterologous vaccines expressing a mosaic Gag antigen aimed to increase antigenic breadth against a wider spectrum of HIV-1 strains. Priming using a DNA vaccine via in vivo electroporation, followed by boosting with a live replication-competent modified vaccinia TianTan (MVTT) vectored vaccine, elicited greater and broader protective Gag-specific immune responses in mice. Compared to DNA or MVTT homologous immunization, the heterologous DNA/MVTT vaccination resulted in higher frequencies of broadly reactive, Gag-specific, polyfunctional, long-lived cytotoxic CD8+ T cells, as well as increased anti-Gag antibody titer. Importantly, the DNA/MVTT heterologous vaccination induced protection against EcoHIV and mesothelioma AB1-Gag challenges. In summary, the stronger protective Gag-specific immunity induced by the heterologous regimen using two safe vectors shows promise for further development to enhance anti-HIV-1 immunity. Our study has important implications for immunogen design and the development of an effective HIV-1 heterologous vaccination strategy.

Original languageEnglish
Pages (from-to)4621-4632
Number of pages12
Issue number31
Publication statusPublished - 25 Jul 2018

Scopus Subject Areas

  • Molecular Medicine
  • Immunology and Microbiology(all)
  • veterinary(all)
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

User-Defined Keywords

  • Heterologous vaccine
  • HIV-1
  • Immune breadth
  • Immune potency
  • Mosaic Gag antigen
  • Protective immunity


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