Interleukin-12 (IL-12), consisting of p40 and p35 subunits, produces both p70 heterodimer and free p40. p70 is essential for the induction of T-helper 1 (Th1) and cytotoxic T-cell (CTL) immunity, whereas p40 inhibits p70-mediated function. Here, we found that mutations introduced into N-glycosylation sites (N220 of murine p40 and N222 of human p40) reduced secretion of p40 but not p70. Co-immunization of N220 mutant mlL-12 gene with hepatitis C virus (HCV) E2 DNA significantly enhanced long-term E2-specific CD8+ T-cell response and protection against tumor challenge compared with that of wild type. Our results indicate that the ratio of p70 to p40 is important for generating sustained long-term cell-mediated immunity. Thus, the mutant lL-12 could be utilized for the development of DNA vaccines as an adjuvant for the generation of long-term memory T-cell responses.
Bibliographical noteFunding Information:
Acknowledgments The authors acknowledge Sang-Chun Lee and Su-Il Park for devoted animal care. We are grateful to Hye-Ryun Kim and Se-Hwan Yang for faithful reading and comments. This work was supported by National Research Laboratory grant from Korea Institute of Science and Technology Evaluation and Planning (2000-N-NL-01-C-202) and grants from POSCO (2000Y013), Superior Research Center supported by Korea Science and Engineering Foundation, and ProGen Co. Ltd.
All Science Journal Classification (ASJC) codes
- Applied Microbiology and Biotechnology
- Molecular Medicine
- Biomedical Engineering