-
[show abstract]
[hide abstract]
ABSTRACT: Most current assays of HDL functional properties are cell-based. We have developed a fluorometric biochemical assay based on the oxidation of dihydrorhodamine 123 (DHR) by HDL. This cell-free assay assesses the intrinsic ability of HDL to be oxidized by measuring increasing fluorescence due to DHR oxidation over time. The assay distinguishes the oxidative potential of HDL taken from different persons, and the results are reproducible. Direct comparison of this measurement correlated well with results obtained using a validated cell-based assay (r(2) = 0.62, P < 0.001). The assay can be scaled from a 96-well format to a 384-well format and, therefore, is suitable for high-throughput implementation. This new fluorometric method offers an inexpensive, accurate, and rapid means for determining the oxidative properties of HDL that is applicable to large-scale clinical studies.
The Journal of Lipid Research 09/2011; 52(12):2341-51. · 5.56 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The role of pro-inflammatory lipids in systemic immune activation in HIV infection remains largely unknown. We hypothesized that HIV-1-infected persons on antiretroviral therapy would have pro-inflammatory high density lipoprotein (HDL), and that an apoA-1 mimetic peptide might reverse the inflammatory properties of HDL in these persons.
Plasma was obtained from 10 HIV-1-infected individuals on combination antiretroviral therapy with suppressed viremia and was incubated with the apoA-I mimetic peptide L-4F or sham-treated prior to isolation of HDL. The HDL that was isolated from each sample was tested for its ability to inhibit LDL-induced MCP-1 production in cultures of human aortic endothelial cells.
We found in a small pilot study of HIV-1-infected individuals with suppressed viremia on combination antiretroviral therapy that oxidative stress and inflammation in HIV-1 are associated with a marked reduction of HDL antioxidant/anti-inflammatory activities. In vitro, these abnormalities were significantly improved by treatment with the apoA-1 mimetic peptide, 4F.
These preliminary observations suggest that the anti-inflammatory properties of HDL are defective in HIV-1-infected persons despite treatment that is considered to be virologically successful.
Lipids in Health and Disease 02/2011; 10:35. · 2.17 Impact Factor
-
Arumugam Balamurugan,
Martha J Lewis,
Christina M R Kitchen,
Michael N Robertson,
John W Shiver,
Eric S Daar,
Jacqueline Pitt,
Ayub Ali,
Hwee L Ng, Judith S Currier,
Otto O Yang
[show abstract]
[hide abstract]
ABSTRACT: Vaccination for human immunodeficiency virus type 1 (HIV-1) remains an elusive goal. Whether an unsuccessful vaccine might not only fail to provoke detectable immune responses but also could actually interfere with subsequent natural immunity upon HIV-1 infection is unknown. We performed detailed assessment of an HIV-1 gag DNA vaccine recipient (subject 00015) who was previously uninfected but sustained HIV-1 infection before completing a vaccination trial and another contemporaneously acutely infected individual (subject 00016) with the same strain of HIV-1. Subject 00015 received the vaccine at weeks 0, 4, and 8 and was found to have been acutely HIV-1 infected around the time of the third vaccination. Subject 00016 was a previously HIV-1-seronegative sexual contact who had symptoms of acute HIV-1 infection approximately 2 weeks earlier than subject 00015 and demonstrated subsequent seroconversion. Both individuals reached an unusually low level of chronic viremia (<1,000 copies/ml) without treatment. Subject 00015 had no detectable HIV-1-specific cytotoxic T-lymphocyte (CTL) responses until a borderline response was noted at the time of the third vaccination. The magnitude and breadth of Gag-specific CTL responses in subject 00015 were similar to those of subject 00016 during early chronic infection. Viral sequences from gag, pol, and nef confirmed the common source of HIV-1 between these individuals. The diversity and divergence of sequences in subjects 00015 and 00016 were similar, indicating similar immune pressure on these proteins (including Gag). As a whole, the data suggested that while the gag DNA vaccine did not prime detectable early CTL responses in subject 00015, vaccination did not appreciably impair his ability to contain viremia at levels similar to those in subject 00016.
Journal of Virology 03/2008; 82(6):2784-91. · 5.40 Impact Factor
