title: Efficient augmentation of a long-lasting immune responses in HIV-1 gag DNA vaccination by IL-15 plasmid boosting.
abstract: Cytokines are major regulators of the immune response, and have been used as adjuvants to improve vaccine potency. In this study, we investigated the adjuvant effects of interleukin (IL)-15 on improving the immunogenicity of human immunodeficiency virus (HIV)-1 gag DNA vaccine in Balb/c mice. During a 370-day follow-up, cellular and humoral immune responses in three separate cohorts of mice were monitored. These results were exemplified through: lymphocyte proliferation, induction of antigen-specific CD8(+) T lymphocytes, long-term production of specific antibodies, and proportion of differentiated memory CD8(+) T cells. These data revealed that just boost of IL-15 at day 8 after co-immunization induced more homeostatic cell proliferation, augmented proliferation frequency of IFN-gamma-secreting antigen-specific CD8(+) T lymphocytes, maintained the long-lasting humoral immune response and promoted the turnover of memory T cell precursors into central memory T cells. Taken together, our data demonstrated that a single IL-15 boosting can enhance both the humoral and cellular immune responses of the HIV-1 gag DNA vaccination. This novel boosting strategy may facilitate the application of IL-15 as an adjuvant for HIV vaccination.
authors.affiliation: Department of Immunology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Li
authors.forename: Shirui
authors.initials: S
authors.lastname: Li
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.forename: Bixia
authors.initials: B
authors.lastname: Tang
authors.forename: Lianxian
authors.initials: L
authors.lastname: Cui
authors.forename: Wei
authors.initials: W
authors.lastname: He
mesh_terms: D016915:AIDS Vaccines / Q000276:immunology*; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D049109:Cell Proliferation; D005260:Female; D015483:HIV Antibodies / Q000097:blood; D015658:HIV Infections / Q000276:immunology / Q000517:prevention & control*; D007117:Immunization, Secondary; D007156:Immunologic Memory; D007371:Interferon-gamma / Q000096:biosynthesis; D019409:Interleukin-15 / Q000276:immunology*; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D016176:T-Lymphocyte Subsets / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*; D054301:gag Gene Products, Human Immunodeficiency Virus / Q000276:immunology*
chemical_list: D016915:AIDS Vaccines; D015483:HIV Antibodies; D019409:Interleukin-15; D019444:Vaccines, DNA; D054301:gag Gene Products, Human Immunodeficiency Virus; D007371:Interferon-gamma