Design, construction, and characterization of a dual-promoter multigenic DNA vaccine directed against an HIV-1 subtype C/B′ recombinant

An effective vaccine against HIV-1 is generally considered the best hope for controlling the raging AIDS pandemic. As a part of our AIDS vaccine development effort, we constructed a dual-promoter plasmid capable of high-level expression of 2 independent transgenes. HIV-1 gag, pol, env, nef, and tat from a primary subtype C/B′ CCR5-tropic HIV-1 were "codon" optimized, modified to eliminate known functional activity, and assembled using an overlapping polymerase chain reaction into 2 plasmids: ADVAX-I (containing env and gag) and ADVAX-II (containing pol and nef-tat). These 2 dual-promoter candidate vaccines showed levels of HIV-1 gene expression comparable to those observed with single-gene plasmids in vitro. Importantly, immunization of mice with these vaccine constructs resulted in dose-dependent multigenic CD4 and CD8 T-cell responses equivalent to those provided by vaccination with single-gene plasmids. With input from the US Food and Drug Administration, ADVAX-I and ADVAX-II have since been combined as a single candidate DNA vaccine, ADVAX. A phase 1 clinical trial of this product has been successfully completed, and its use in prime-boost studies is now underway. © 2008 Lippincott Williams & Wilkins, Inc.link_to_subscribed_fulltex

Enhancement of HIV DNA vaccine immunogenicity by the NKT cell ligand, α-galactosylceramide

A number of studies have shown that the natural killer T cell (NKT) ligand α-galactosylceramide (α-GalCer) serves as an adjuvant for various vaccines, including viral vaccines, parasite vaccines and protein vaccines. In this report, we investigated the adjuvant activity of α-GalCer on HIV-1 DNA vaccines in mice. This is a first study to show that α-GalCer can enhance the immunogenicity of DNA vaccines, since co-administration of α-GalCer with suboptimal doses of DNA vaccines greatly enhanced antigen-specific CD4+ T-cell and CD8+ T-cell responses. Differently from other vaccines, α-GalCer was also able to enhance HIV-specific antibody response 10-fold. It is of practical importance to find out that, in a DNA prime-DNA boost regimen, the adjuvant activity of α-GalCer was most profound when co-administered at the priming, but not at the boosting phase. In a dose-sparing experiment, we found that the level of cell-mediated immune responses in mice vaccinated with 5 μg of DNA in the presence of α-GalCer was equivalent to that of mice vaccinated with 50 μg of DNA in the absence of α-GalCer. Finally, results from CD1d and interferon-γ receptor knockout mice confirm our previous data and determine the mechanistic dependence upon these molecules. These results illustrate that α-GalCer enhances the immunogenicity of DNA vaccines in a mechanism-based fashion. Since both mice and humans share the CD1d molecule, this information may aid in designing more effective DNA vaccines and vaccine adjuvants against HIV-1. © 2008 Elsevier Ltd. All rights reserved.link_to_subscribed_fulltex

A randomized placebo-controlled study of intravenous montelukast for the treatment of acute asthma

Background: Current treatments for acute asthma provide inadequate benefit for some patients. Intravenous montelukast may complement existent therapies.Objective: To evaluate efficacy of intravenous montelukast as adjunctive therapy for acute asthma.Methods: A total of 583 adults with acute asthma were treated with standard care during a #60-minute screening period.Patients with FEV1 #50% predicted were randomly allocated to intravenous montelukast 7 mg (n 5 291) or placebo (n 5 292) in addition to standard care. This double-blind treatment period lasted until a decision for discharge, hospital admission, or discontinuation from the study. The primary efficacy endpoint was the time-weighted average change in FEV1 during 60minutes after drug administration. Secondary endpointsincluded the time-weighted average change in FEV1 at various intervals (10-120 minutes) and percentage of patients with treatment failure (defined as hospitalization or lack of decision to discharge by 3 hours postadministration).Results: Montelukast significantly increased FEV1 at 60 minutes postdose; the difference between change from baseline for placebo (least-squares mean of 0.22 L; 95% CI, 0.17, 0.27) and montelukast (0.32 L; 95% CI, 0.27, 0.37) was 0.10 L (95% CI, 0.04, 0.16). Similar improvements in FEV1-related variables were seen at all time points (all P <.05). Although treatment failure did not differ between groups (OR 0.92; 95% CI, 0.63,1.34), a prespecified subgroup analysis suggests likely benefit for intravenous montelukast at US sites.Conclusion: Intravenous montelukast added to standard care in adults with acute asthma produced significant relief of airway obstruction throughout the 2 hours after administration, with an onset of action as early as 10 minutes