Enantiospecific adjuvant activity of cationic lipid DOTAP in cancer vaccine

Cancer Immunol Immunother. 2011 May;60(5):629-38. doi: 10.1007/s00262-011-0970-1. Epub 2011 Jan 26.


Commercially available DOTAP is a racemic mixture of two enantiomers. The adjuvanticity of each isomer was examined using a peptide/lipid complex as a therapeutic vaccine in an established murine cervical cancer model. This simple vaccine consists of a cationic lipid (DOTAP) and a major histocompatibility complex (MHC) class I-restricted epitope of the Human Papillomavirus (HPV) 16 protein E7. Dose-dependent tumor regression experiments have been completed for racemic DOTAP/E7, (R)-DOTAP/E7 and (S)-DOTAP/E7. Tumor-bearing mice treated with (R)-DOTAP/E7 complexes have shown tumor regression in a dose-dependent manner comparable to those mice treated with a racemic DOTAP with E7 peptide. These data are supported by IFN-γ production by CD8(+) splenocytes, in vivo cytotoxic T-lymphocytes (CTL) response, CD8(+) tumor-infiltrating lymphocytes (TIL), and IFN-γ production by CD8(+) TIL in (R)-DOTAP/E7-vaccinated mice. When (S)-DOTAP/E7 is delivered, tumor progression is delayed. While IFN-γ production is absent from CD8(+) splenocytes in mice vaccinated with (S)-DOTAP/E7, IFN-γ production by CD8(+) TIL is present, supporting our hypothesis that (S)-DOTAP has limited activity. Activation of bone marrow-derived dendritic cells by the enantiomeric formulations has also been evaluated, as well as cytokine production and toxicity with no considerable differences between the groups. The results show the DOTAP enantiomers act differently as adjuvants in vivo, with (R)-DOTAP being more effective at stimulating a CD8(+) anti-tumor response.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic*
  • Animals
  • CD8 Antigens / immunology
  • Cancer Vaccines / administration & dosage
  • Cancer Vaccines / immunology*
  • Cytokines / biosynthesis
  • Dendritic Cells / immunology
  • Fatty Acids, Monounsaturated / chemistry
  • Fatty Acids, Monounsaturated / immunology*
  • Female
  • Interferon-alpha / biosynthesis
  • Interferon-gamma / biosynthesis
  • Lymphocytes, Tumor-Infiltrating / immunology
  • Mice
  • Mice, Inbred C57BL
  • Papillomavirus E7 Proteins / immunology*
  • Quaternary Ammonium Compounds / chemistry
  • Quaternary Ammonium Compounds / immunology*
  • T-Lymphocytes, Cytotoxic / immunology
  • T-Lymphocytes, Cytotoxic / metabolism
  • Uterine Cervical Neoplasms / immunology*
  • Uterine Cervical Neoplasms / therapy*


  • Adjuvants, Immunologic
  • CD8 Antigens
  • Cancer Vaccines
  • Cytokines
  • Fatty Acids, Monounsaturated
  • Interferon-alpha
  • Papillomavirus E7 Proteins
  • Quaternary Ammonium Compounds
  • oncogene protein E7, Human papillomavirus type 16
  • Interferon-gamma
  • 1,2-dioleoyloxy-3-(trimethylammonium)propane