ABSTRACT
BACKGROUND: Development of an effective vaccine is highly needed in order to restrict the AIDS pandemic. DNA vaccines initiate both arms of immunity without the potential of causing disease. HIV-1 p24 and gp41 (gag and env) proteins play important roles in viral pathogenesis and are effective candidates for immune induction and vaccine design. OBJECTIVE: In this study, new DNA vaccine candidates constructed from HIV-1 fused p24-gp41 or gp41 alone were evaluated in Balb/c mice for induction of cellular and humoral immune responses. METHODS: Recombinant plasmids, pcDNA3.1/Hygro expression vector containing immunogenic sequences of fused p24-gp41 or gp41alone were produced. Dendrosome used as a system for carrying vectors in laboratory animals, and an IL-12 containing vector (pCAGGS-IL-12) was co-immunized with the p24-gp41 vector as a genetic adjuvant. Induction of effective immune responses against the designed vectors as DNA vaccine candidates in Balb/c mice was evaluated. Levels of total antibodies, IgG isotypes (IgG2a and IgG1); IFN-γ and IL-4 were measured by ELISA. MTT assay was used to evaluate lymphoproliferation. RESULTS: The results confirmed that the immunogenic epitopes of both p24 and gp41 genes are highly effective inducers of immune responses, and administration of fused p24-gp41 alone or along with IL-12 resulted in further enhancement of immune responses. Group 4 that received fused fragments (p24-gp41) along with an IL-12 expressing vector demonstrated a significantly higher Stimulation Index (SI) and IFN-γ production (p<0.0001) with a significant increase in IgG2a/IgG1 ratio, indicating the stimulation of CMI towards Th1. Although gp41 containing vector (group 6) also showed significant increases in both proliferation and IFN-γ production, the responses were persistently lower than that of p24-gp41 containing vectors. Total antibody production was highest in group 6 as expected. CONCLUSION: Dendrosome proved to be an efficient carrier of recombinant plasmids constructed in this study. Further studies are necessary to evaluate these constructs as HIV vaccine candidates.
Subject(s)
AIDS Vaccines/immunology , HIV Infections/prevention & control , HIV-1/immunology , Vaccines, DNA/immunology , Animals , Cells, Cultured , Female , HIV Core Protein p24/genetics , HIV Core Protein p24/immunology , HIV Envelope Protein gp41/genetics , HIV Envelope Protein gp41/immunology , Humans , Immunity, Cellular , Immunity, Humoral , Immunization , Immunoglobulin G/blood , Interferon-gamma/metabolism , Interleukin-12/genetics , Interleukin-12/metabolism , Interleukin-4/blood , Mice , Mice, Inbred BALB C , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunologyABSTRACT
The dependence of the mobility of DNA molecules through an hexagonal array of micropillars on their length and the applied electric field was investigated and it was found that mobility is a nonmonotonic function of their length. Results also revealed that the size dependence of the DNA mobility depends on the applied electric field and there is a crossover around E approximately 25 V/cm for the mobility of lambda-DNA and T4-DNA. These observations are explained in terms of the diffusion process inside the structure affected by the solvent and are modeled using the Langevin and its corresponding Fokker-Planck equations. The phenomenon is generalized under three regimes in a phase diagram relating the electric field and the DNA lengths. The model and the associated phase diagram described here provide an explanation for the conflicting results reported by previous authors (Han et al. on the one hand, and Duong et al. and Inatomi et al. on the other) about the dependence of mobility on the DNA size in lattices near or below the radius of gyration.
