A purified recombinant lipopeptide as adjuvant for cancer immunotherapy

Biomed Res Int. 2014:2014:349783. doi: 10.1155/2014/349783. Epub 2014 Mar 11.

Abstract

Synthetic lipopeptides have been widely used as vaccine adjuvants to enhance immune responses. The present study demonstrated that the tryptic N-terminal fragment of the lipoprotein rlipo-D1E3 (lipo-Nter) induces superior antitumor effects compared to a synthetic lipopeptide. The lipo-Nter was purified and formulated with protein or peptide vaccines to determine if lipo-Nter could be used as a novel adjuvant and could induce antitumor immunity in a cervical cancer model. Purified lipo-Nter activated the maturation of bone marrow-derived dendritic cells (BM-DCs), leading to the secretion of TNF-α through TLR2/6 but not TLR1/2. A recombinant mutant HPV16 E7 (rE7m) protein was mixed with lipo-Nter to immunize the mice; the anti-E7 antibody titers were increased, and the T helper cells were skewed toward the Th1 fate (increased IL-2 and decreased IL-5 secretion). Single-dose injection of rE7m and lipo-Nter inhibited tumor growth, but the injection of rE7m alone did not. Accordingly, lipo-Nter also enhanced the antitumor immunity of the E7-derived peptide but not the synthetic lipopeptide (Pam3CSK4). We demonstrated that the lipo-Nter of a bacterial-derived recombinant lipoprotein is a novel adjuvant that could be used for the development of a new generation of vaccines.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adjuvants, Immunologic / pharmacology*
  • Animals
  • Cell Line, Tumor
  • Dendritic Cells / immunology
  • Female
  • Immunity, Cellular / immunology
  • Immunization / methods
  • Immunotherapy / methods
  • Interleukin-2 / immunology
  • Interleukin-5 / immunology
  • Lipopeptides / immunology*
  • Lipopeptides / pharmacology*
  • Mice
  • Mice, Inbred C57BL
  • Papillomavirus E7 Proteins / immunology
  • Recombinant Proteins / immunology*
  • Recombinant Proteins / pharmacology*
  • T-Lymphocytes, Helper-Inducer / immunology
  • Tumor Necrosis Factor-alpha / immunology
  • Uterine Cervical Neoplasms / immunology*
  • Uterine Cervical Neoplasms / therapy
  • Vaccines, Subunit / immunology

Substances

  • Adjuvants, Immunologic
  • Interleukin-2
  • Interleukin-5
  • Lipopeptides
  • Papillomavirus E7 Proteins
  • Recombinant Proteins
  • Tumor Necrosis Factor-alpha
  • Vaccines, Subunit
  • oncogene protein E7, Human papillomavirus type 16