Sahar Eshghjoo, Asghar Abdoli, Shohreh Khatami, Zahra Noormohammadi
ABSTRACT
Background: Vaccines have been in use as a prophylactic strategy for more than 200 years and remain the best defense against the infectious diseases. New formulations should be adopted to improve efficacy of HIV polytope vaccine. Lack of efficient delivery system is a major obstacle for up taking and transporting the antigenic molecules to the cytosol of antigen presenting cells present by immune cells. To this end, HIV polytope candidate vaccine was formulated with chitosan nanoparticles as biodegradable delivery system.
Materials and methods: The HIV polytope protein was expressed by prokaryotic expression system. The protein purified by Ni-NTA affinity chromatography and dialyzed against PBS buffer for overnight. Next 6 µg/ml of Trimethyl chitosan and 380 µg/ml of purified protein was mixed and solved by adding tripoly phosphate (TPP) solution, at ambient temperature and pH 7.4 while stirring.
Result: The mean size distribution of nanoparticles were determined by dynamic light scattering using Zetasizer . Formulated nanoparticles showed the potential of 10.3 mV and conductivity of 0.0449 mS/cm. loading efficiency was 70%.
Test Results showed that Immunization with HIV-1 tat/pol/gag/env led to a significant increase in the proliferative responses of lymphocytes, IL-4 and IFN-γ cytokine production and humoral immune response in comparison with the control groups.
Background: Conclusion: These findings demonstrate that N-Trimethyl chitosan nanoparticles may be a potent delivery system for HIV polytope candidate vaccine delivery.
Key Words: AIDS, Vaccine, Chitosan, Formulation, Polytope.