Interleukin-15 Increases Vaccine Efficacy through a Mechanism Linked to Dendritic Cell Maturation and Enhanced Antibody Titers
Abstract
Interleukin-15 (IL-15) is generally considered to be a growth factor for natural killer cells and for sustaining T-cell memory. Previous data from our laboratory demonstrated that IL-15 is also an important factor for developing human dendritic cells. In this study, we investigated the effect of IL-15 on antibody responses to a recombinant staphylococcal enterotoxin B (SEB) vaccine (STEBVax), in a pre-clinical model of toxic-shock syndrome induced by SEB. We observed that mouse spleen cells treated with IL-15 in ex vivo culture gained a dendritic cell-like phenotype. Administration of IL-15 to mice also resulted in an increased number of mature CD11c+ dendritic cells in mouse spleens. A significant, IL-15 dose-dependent increase in antigen-specific antibody was observed after co-administration with vaccine and an aluminum-based adjuvant (alhydrogel). Furthermore, the co-administration of IL-15 with STEBVax and alhydrogel also protected mice from lethal toxic shock above the levels that obtained without IL-15. Thus, the vaccine response enhanced by IL-15 appears to be mediated by mature dendritic cells, and results in prevalent sero-conversion to Th2-dependent antibodies. This suggests a potential use of IL-15 as an adjuvant for antibody-dependent responses to vaccines.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 26, 2007
- Accession Number
- ADA476405
Entities
People
- Gordon T. Ruthel
- Kamal U. Saikh
- Robert G Ulrich
- Steven Nystrom
- Teri L. Kissner
Organizations
- United States Army Medical Research Institute of Infectious Diseases