Intranasal administration of human immunodeficiency virus type‐1 (HIV‐1) DNA vaccine with interleukin‐2 expression plasmid enhances cell‐mediated immunity against HIV‐1

Open Access
Publisher Website
Google Scholar
Abstract
DNA vaccine against human immunodeficiency virus type‐1 (HIV‐1) can induce substantial levels of HIV‐1‐specific humoral and cell‐mediated immunity. To develop more potent HIV‐1 DNA vaccine formulations, we used a murine model to explore the immunomodulatory effects of an interleukin‐2 (IL‐2) expression plasmid on an HIV‐1 DNA vaccine following intranasal administration of the combination. When the vaccine and expression plasmid were incorporated into cationic liposomes and administered to mice, the HIV‐1‐specific delayed‐type hypersensitivity response and cytotoxic T lymphocyte activity were significantly increased. Restimulated immune lymphoid cells showed enhanced production of both IL‐2 and interferon‐γ and reduced secretion of IL‐4. The level of total antibody to HIV‐1 antigen was not greatly changed by coadministration of the DNA vaccine and IL‐2 expression plasmid. An analysis of serum HIV‐1‐specific IgG subclasses showed a significant drop in the IgG1/IgG2a ratio in the group that received the plasmid–vaccine combination. These results demonstrate that the IL‐2 expression plasmid strongly enhances the HIV‐1‐specific immune response via activation of T helper type‐1 cells.