Enhancement of VP1-specific immune responses and protection against EMCV-K challenge by co-delivery of IL-12 DNA with VP1 DNA vaccine

You Suk Suh, Sang Jun Ha, Chu Hee Lee, Jeong Im Sin, Young Chul Sung

Research output: Contribution to journalArticle

9 Citations (Scopus)


It has been reported that co-delivery of IL-12 DNA with a DNA vaccine further enhances antigen (Ag)-specific protective immunity in pathogenic challenge models. However, the enhancing effects of antibody by IL-12 have been controversial. To clarify this issue, we constructed an IL-12 expression vector, co-immunized IL-12 DNA with an encephalomycocarditis virus (EMCV)-D VP1 plasmid vaccine, and then evaluated immune modulatory effects and protection against lethal EMCV-K challenge. We observed that VP1-specific IgG production, as well as seroconversion rates, were significantly enhanced by IL-12 co-injection, indicating that IL-12 can enhance antibody responses in this model system. In particular, co-injection with VP1 plus IL-12 DNA into the same leg enhanced systemic Ag-specific IgG production to a significantly greater extent than either the separate leg injection of VP1 and IL-12 DNA or VP1 DNA vaccine alone. This suggests that local co-expression of IL-12 along with antigens is more important for enhanced antibody production. Furthermore, IgG2a isotype was significantly enhanced by IL-12 DNA co-injection, indicating a Th1 bias. In addition, co-delivery of IL-12 DNA was demonstrated to enhance VP1-specific Th cell proliferative responses. When animals were challenged with a lethal dose of EMCV-K, IL-12 DNA-co-immunized animals exhibited enhanced survival, as compared to VP1 DNA vaccine alone. These studies suggest that IL-12 plays an important role in increasing Ag-specific Th1 type antibody and cellular responses, resulting in enhanced protection against lethal EMCV-K challenge.

Original languageEnglish
Pages (from-to)1891-1898
Number of pages8
Issue number15-16
Publication statusPublished - 2001 Feb 28

All Science Journal Classification (ASJC) codes

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

Fingerprint Dive into the research topics of 'Enhancement of VP1-specific immune responses and protection against EMCV-K challenge by co-delivery of IL-12 DNA with VP1 DNA vaccine'. Together they form a unique fingerprint.

  • Cite this