title: Stimulation of Tumor-Specific Immunity by p5 HER-2/neu Generated Peptide Encapsulated in Nano-liposomes with High Phase Transition Temperature Phospholipids.
abstract: BACKGROUND
  The aim of this study is to evaluate the possible advantages of liposomes with high transition temperature (Tm) in the function of a vaccine for P5 HER2/neu-generated peptide and its adjuvant action to elicit CD8+ T cell response and its efficacy in TUBO in vivo tumor mice model, which over expresses the HER2/neu oncogene. P5, a hydrophobic peptide, was encapsulated in the nanoliposomes consisting of DSPC/DSPG/Chol(Tm 54°C) with a chaotropic loading system via 7M urea and described by size, zeta potential, encapsulation efficiency, and the structural stability of SDS-PAGE.
  
  
  METHODS
  We immunized the mice for three times subcutaneously based on a two-week intervals using encapsulated peptide in the nanoliposomes, empty liposome, P5 in PBS, and PBS. Enzyme-linked immunospot assay, cytotoxicity test, and flow cytometric studies followed by the size of tumor and survival time measurements, which were done in TUBO tumor mice version.
  
  
  RESULTS
  Findings of ELISpot and flow cytometric analysis showed that immunization with Lip-p5 nanoliposomes has enhanced the antigen-specific IFN-γ response of CD8+ T cells and induced CTL response, which resulted in a smaller tumor and longer survival time. In addition to increase in amounts of IFN-γ-CD8+ T cells in a group, which was immunized with Lip-P5, our findings also revealed a Th1 shift in the group immunized with an empty liposome with reduced frequencies of IL-4-producing cells and increase of IFN-γ-producing cells.
  
  
  CONCLUSIONS
  The results indicated that simple liposomes consisting of phospholipids with high transition temperature could be an effective vaccine vehicle for tumor-associated antigens for inducing cell mediate immunity.
authors.affiliation: Department of Basic Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran.
authors.forename: Mona
authors.initials: M
authors.lastname: Yazdani
authors.affiliation: Department of Immunology, Faculty of Medicine, ShahidBeheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Seyed Amir
authors.initials: SA
authors.lastname: Jalali
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Badiee
authors.affiliation: School of Pharmacy, ShahidBeheshti University of Medical Science, Tehran, Iran.
authors.forename: Sheida
authors.initials: S
authors.lastname: Shariat
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mercedeh
authors.initials: M
authors.lastname: Mansourian
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Leila
authors.initials: L
authors.lastname: Arabi
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Azam
authors.initials: A
authors.lastname: Abbasi
authors.affiliation: Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Saberi
authors.affiliation: Biotechnology Research Center, Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mahmoud Reza
authors.initials: MR
authors.lastname: Jaafari
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005260:Female; D007371:Interferon-gamma / Q000276:immunology; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles; D009368:Neoplasm Transplantation; D010446:Peptide Fragments / Q000494:pharmacology*; D010743:Phospholipids / Q000737:chemistry*; D018719:Erb-b2 Receptor Tyrosine Kinases; D044366:Transition Temperature
chemical_list: D019496:Cancer Vaccines; D007371:Interferon-gamma; D008081:Liposomes; D010446:Peptide Fragments; D010743:Phospholipids; D018719:Erb-b2 Receptor Tyrosine Kinases
keywords: Cancer vaccine; P5 HER2/neu peptide; cell mediated immunity; liposomes; nanoliposomes; phase transition temperature