Tehran University of Medical Sciences

Science Communicator Platform

Stay connected! Follow us on X network (Twitter):
Share this content! On (X network) By
Co-Utilization of a Tlr5 Agonist and Nano-Formulation of Hiv-1 Vaccine Candidate Leads to Increased Vaccine Immunogenicity and Decreased Immunogenic Dose: A Preliminary Study Publisher Pubmed



Rostami H1 ; Ebtekar M1 ; Ardestani MS2 ; Yazdi MH3, 4 ; Mahdavi M5
Authors
Show Affiliations
Authors Affiliations
  1. 1. Department of Immunology, Tarbiat Modares University, Tehran, Iran
  2. 2. Department of Radiopharmacy and Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
  3. 3. Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
  4. 4. Evidence Based Medicine Group, Pharmaceutical Biotechnology Sciences Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
  5. 5. Department of Immunology, Pasteur Institute of Iran, Tehran, Iran

Source: Immunology Letters Published:2017


Abstract

Vaccines currently available for AIDS show poor efficiency, demonstrating the need for new strategies to increase their immunogenicity. In this study, the HIV-1P24-Nef peptide was used as a model vaccine, followed by utilization of a novel strategy to increase its immunogenicity. There is a growing interest in using TLR agonists for vaccine formulations. Such molecules bind to their receptors on immune cells, especially the cell surface of antigen presenting cells, thereby activating these cells and inflammatory responses. In the present study, FLiC (flagellin molecule sequence from Pseudomonas aeruginosa) was used as a TLR5 agonist. In addition, PLGA nanoparticles were used as a transmitter system to enhance vaccine efficiency and its effective transfer to immune systems. In light of this, the P24-Nef peptide was conjugated to FLiC through chemical reactions. The HIV-1P24-Nef/FLiC conjugate was constructed as a nano-vaccine using PLGA particles. Subsequently, mice were immunized intradermally three times with three-week intervals with HIV-p24-Nef/FLiC/PLGA, HIV-p24-Nef/PLGA, FLiC/PLGA, PLGA, and PBS in two doses (20 and 5 μg). Three weeks after the last booster injection, cell proliferation was assessed using the Brdu/ELISA assay, and cytotoxicity was evaluated by CFSE and splenocyte cytokine secretion (IL-4 and IFN-γ); in addition, IgG1 and IgG2a antibody isotype titers were determined using a commercial ELISA kit. Our results showed that Co-utilization of TLR5 and nano-particles not only improves vaccine immunogenicity but also decreases the immunogenic dose of vaccine candidate required. We showed that the immune system was effectively stimulated via the nano-vaccination strategy using the TLR5 agonists. The effect of this strategy showed variations in different parameters of the immune system; in this regard, cellular immune responses had a higher stimulation level, compared with humoral immune responses. © 2017
Experts (# of related papers)