In vitro effect of branched polyethyleneimine (bPEI) on cells infected with human immunodeficiency virus: enhancement of viral replication.

Polyethyleneimine (PEI) is a chemical compound that used is as a carrier in gene therapy/delivery. Some studies have investigated the microbicidal potential and antiviral activity (prophylactic or therapeutic) of PEI and its derivatives. The aim of this study was to investigate the effect of branched polyethyleneimine (bPEI) on human immunodeficiency virus (HIV) replication. Infected cells were treated with bPEI for 36 hours, and the concentration of the viral protein P24 (as a virus replication marker) was determined in cell culture supernatants. This study indicated that bPEI increased HIV replication and decreased the viability of infected cells through cytotoxicity. The toxicity of bPEI its association with and cell death (apoptosis, autophagy and necrosis) have been reported in several studies. To investigate bPEI-induced cytotoxicity, we examined apoptosis and autophagy in cells treated with bPEI, and a significant increase in HIV viral load, the P24 antigen level, autophagy, and necrosis observed. Thus, treatment with bPEI leads to cytotoxicity and higher HIV virus yield.

Inherent anti-HIV activity of biocompatible anionic citrate-PEG-citrate dendrimer.

The development of new combinations to empower better protection against HIV infection is particularly important. Anionic polymers can block HIV infection. In the current study, first generation (G1) and second generation (G2) novel water-soluble anionic citrate-PEG-citrate dendrimers were synthesized and characterized with Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and dynamic light scattering (DLS) methods. After the biocompatibility of the G2 dendrimer was determined, its antiviral activity was evaluated. This function may contribute to the peripheral groups of this dendrimer (carboxylate group). In order to measure the inhibitory effect of G2 on HIV infection, both pre-treatment (treated with G2 dendrimer before HIV infection) and co-treatment (simultaneously treated with G2 dendrimer and HIV infection) were used in vitro. The results showed the good synthesis of the G2 dendrimer, and the dendrimer showed antiviral properties (ICC50:0.4 mM) and low toxicity (CC50:0.6 mM) at high concentrations. A strong inhibitory effect was found when the co-treatment approach was used. This study achieved promising results which encourage the use of G2 dendrimers as anti-HIV agents.

Conjugated anionic PEG-citrate G2 dendrimer with multi-epitopic HIV-1 vaccine candidate enhance the cellular immune responses in mice.

Multi-epitope vaccines might cause immunity against multiple antigenic targets. Four immunodominant epitopes of HIV-1 genome were used to construct a polytope vaccine, formulated by dendrimer. Two regimens of polytopes mixture with dendrimer were utilized to immunize BALB/c mice. Adjuvants were also used to boost immune responses. The conjugated polytope could arouse significant cellular immune responses (P < 0.05) and Th1 response showed higher intensity compared to Th2 (P < 0.05). Our study depicted that conjugated dendrimer with multi-epitopic rHIVtop4 would efficiently induce cell-mediated immune responses and might be considered as promising delivery system for vaccines formulation.