Antitumor activity of a self-adjuvanting glyco-lipopeptide vaccine bearing B cell, CD4+ and CD8+ T cell epitopes

Cancer Immunol Immunother. 2009 Feb;58(2):187-200. doi: 10.1007/s00262-008-0537-y. Epub 2008 Jun 27.

Abstract

Molecularly defined synthetic vaccines capable of inducing both antibodies and cellular anti-tumor immune responses, in a manner compatible with human delivery, are limited. Few molecules achieve this target without utilizing external immuno-adjuvants. In this study, we explored a self-adjuvanting glyco-lipopeptide (GLP) as a platform for cancer vaccines using as a model MO5, an OVA-expressing mouse B16 melanoma. A prototype B and T cell epitope-based GLP molecule was constructed by synthesizing a chimeric peptide made of a CD8(+) T cell epitope, from ovalbumin (OVA(257-264)) and an universal CD4(+) T helper (Th) epitope (PADRE). The resulting CTL-Th peptide backbones was coupled to a carbohydrate B cell epitope based on a regioselectively addressable functionalized templates (RAFT), made of four alpha-GalNAc molecules at C-terminal. The N terminus of the resulting glycopeptides (GP) was then linked to a palmitic acid moiety (PAM), obviating the need for potentially toxic external immuno-adjuvants. The final prototype OVA-GLP molecule, delivered in adjuvant-free PBS, in mice induced: (1) robust RAFT-specific IgG/IgM that recognized tumor cell lines; (2) local and systemic OVA(257-264)-specific IFN-gamma producing CD8(+) T cells; (3) PADRE-specific CD4(+) T cells; (4) OVA-GLP vaccination elicited a reduction of tumor size in mice inoculated with syngeneic murine MO5 carcinoma cells and a protection from lethal carcinoma cell challenge; (5) finally, OVA-GLP immunization significantly inhibited the growth of pre-established MO5 tumors. Our results suggest self-adjuvanting glyco-lipopeptide molecules as a platform for B Cell, CD4(+), and CD8(+) T cell epitopes-based immunotherapeutic cancer vaccines.

Publication types

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

MeSH terms

  • Adjuvants, Immunologic*
  • Animals
  • B-Lymphocytes / immunology*
  • CD4-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / immunology*
  • Cancer Vaccines / chemistry
  • Cancer Vaccines / immunology*
  • Cancer Vaccines / therapeutic use
  • Cell Line
  • Cell Line, Tumor
  • Epitopes, T-Lymphocyte / immunology*
  • Female
  • Glycolipids / immunology
  • Humans
  • Interferon-gamma / metabolism
  • Lipopeptides / therapeutic use*
  • Mice
  • Mice, Inbred C57BL
  • Molecular Structure
  • Ovalbumin / metabolism
  • Protein Kinases / immunology
  • TOR Serine-Threonine Kinases

Substances

  • Adjuvants, Immunologic
  • Cancer Vaccines
  • Epitopes, T-Lymphocyte
  • Glycolipids
  • Lipopeptides
  • Interferon-gamma
  • Ovalbumin
  • Protein Kinases
  • MTOR protein, human
  • mTOR protein, mouse
  • TOR Serine-Threonine Kinases