title: Liposome-based systems for anti-tumor vaccination: influence of lipopeptide adjuvants.
abstract: We have developed liposome-based synthetic constructs incorporating peptide epitope(s) (ErbB2 p63-67 CTL which is overexpressed in many tumors and/or HA 307-319 T-helper) and lipopeptide adjuvants (Pam3CysSerSer, Pam3CysAlaGly) in order to elicit an anti-tumor immune response. The epitopes, derivatized with a linker containing a cysteine residue, were conjugated on preformed vesicles (dia. approximately 100 nm) containing lipopeptides functionalized with thiol reactive groups (maleimide or bromoacetyl). The therapeutic efficacy of these constructs was evaluated on a Balb/c mice tumor model inoculated with syngenic murine renal carcinoma (Renca) cells expressing human ErbB2 (Her2/neu) receptor. A successful therapeutic vaccination was obtained which was antigen specific. Furthermore, it appeared that the nature of the polar head group of the lipopeptide adjuvant and also its type of functionalization influence the efficacy of the construct. In our study, the best results were obtained with formulations containing a Pam3CSS anchor in association with the CTL and Th epitopes. Considering these promising results studies are in progress with a new generation of liposomes that incorporate a neutral lipid--lacking adjuvant properties--that serves as anchor of the peptide epitopes and new adjuvants synthesized in our laboratory, which are screened for their antitumour activity in a therapeutic setting.
authors.affiliation: Institut Gilbert Laustriat, UMR 7175-LC01 CNRS/Université Louis Pasteur, Département de Chimie Bioorganique, Faculté de Pharmacie, Illkirch, France.
authors.forename: Béatrice
authors.initials: B
authors.lastname: Heurtault
authors.forename: Jean-Sébastien
authors.initials: JS
authors.lastname: Thomann
authors.forename: Justyna
authors.initials: J
authors.lastname: Jedrzejewska
authors.forename: Winfried S
authors.initials: WS
authors.lastname: Wels
authors.forename: Francis
authors.initials: F
authors.lastname: Schuber
authors.forename: Benoît
authors.initials: B
authors.lastname: Frisch
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage* / Q000737:chemistry; D000595:Amino Acid Sequence; D000818:Animals; D019496:Cancer Vaccines / Q000008:administration & dosage*; D007680:Kidney Neoplasms / Q000628:therapy*; D008081:Liposomes; D051379:Mice; D008969:Molecular Sequence Data; D010455:Peptides / Q000008:administration & dosage* / Q000737:chemistry
chemical_list: D000276:Adjuvants, Immunologic; D019496:Cancer Vaccines; D008081:Liposomes; D010455:Peptides