[Show abstract][Hide abstract] ABSTRACT: Data from prospectively planned cohort studies on risk of major clinical outcomes and prognostic factors for patients with influenza A(H1N1)pdm09 virus are limited. In 2009, in order to assess outcomes and evaluate risk factors for progression of illness, two cohort studies were initiated: FLU 002 in outpatients and FLU 003 in hospitalized patients.
PLoS ONE 07/2014; 9(7):e101785. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives: After DNA or RNA virus infection, cytosolic foreign DNA or RNA derived from the infecting viruses is recognized by intracellular pathogen recognition receptors (PRRs) and induces activation of the innate immune system. Transfection of DNA has been used as an experimental model for DNA virus-mediated innate responses. We have previously reported that DNA transfection preferentially induces Type-III IFN (IFN-λ1) rather than Type-I IFN (IFN-β). In this study, we compared the DNA-mediated immune response between healthy controls and HIV-1 infected patients with undetectable viral loads and assessed potential innate immune responses in these patients.
Methods: The study consisted of 50 HIV-1 negative healthy donors, 46 patients on combination antiretroviral therapy with HIV-1 viral loads <50 copies/ml and 7 long term non-progressors (LTNPs). PBMCs were isolated from whole blood using Ficoll-Paque. DNA transfection was performed using Lipofectamine 2000. After 22 hours incubation, total cellular RNA was extracted and real time RT-PCR was performed to determine gene expression level of IFN-λ1, IFN-β and RANTES. Gene induction was compared by fold change.
Results: Baseline levels of endogenous gene expression of IFN-λ1, IFN-β and RANTES in HIV-1 patients were higher than in controls. Following DNA transfection, both HIV infected patients and healthy controls induced gene induction, however, the induction in HIV-1 patients was at a significantly lower level compared to uninfected controls.
Conclusion: HIV-1 treated patients with undetectable viral loads have lower levels of innate immune responses via cytosolic DNA sensing systems. This may be caused by persistent immune activation.
Journal of AIDS & Clinical Research 06/2014; 5(6):315. · 6.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IL-27 is an immunomodulatory cytokine with potent anti-HIV properties in PBMCs, CD4+ T cells, macrophages and immature dendritic cells. Previous smaller studies have suggested that HIV-1 infection may alter IL-27 and influence HIV-1 pathogenesis. The aim of this study was to examine the relationship between plasma IL-27 levels in a well-characterised cohort of HIV-1 infected patients.
PLoS ONE 06/2014; 9(6):e98989. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: HIV infection and the associated chronic immune activation alter T cell homeostasis leading to CD4 T cell depletion and CD8 T cell expansion. The mechanisms behind these outcomes are not totally defined and only partially explained by the direct cytopathic effect of the virus. In this manuscript, we addressed the impact of lymphopenia and chronic exposure to IFN-α on T cell homeostasis. In a lymphopenic murine model, this interaction led to decreased CD4 counts and CD8 T cell expansion in association with an increase in the Signal Transducer and Activator of Transcription 1 (STAT1) levels resulting in enhanced CD4 T cell responsiveness to IFN-α. Thus, in the setting of HIV infection, chronic stimulation of this pathway could be detrimental for CD4 T cell homeostasis.
[Show abstract][Hide abstract] ABSTRACT: Determining the precise lifespan of human T-cell is challenging due to inability of standard techniques to distinguish between dividing and dying cells. Here, we measured the duration of in vivo persistence by following a pool of T-cells that were "naturally" labeled with a single integrated clone of a replication-incompetent HIV-1 provirus.
Utilizing a combination of techniques we were able to sequence/map an integration site of a unique provirus with a stop codon at position 42 of the HIV-1 protease. In-vitro reconstruction of this provirus into an infectious clone confirmed its inability to replicate. By combing cell separation and integration site-specific PCR we were able to follow the fate of this single provirus in multiple T-cell subsets over a 20-year period. As controls, a number of additional integrated proviruses were also sequenced.
The replication-incompetent HIV-1 provirus was solely contained in the pool of effector memory (EM) CD4 T-cell for 17 years. The percentage of the total EM CD4 T-cells containing the replication-incompetent provirus peaked at 1% with a functional half-life of 11.1 months. In the process of sequencing multiple proviruses, we also observed high levels of lethal mutations in the peripheral blood pool of proviruses.
These data indicate that human EM CD4 T-cells are able to persist in vivo for >17 years without detectably reverting to a central memory phenotype. A secondary observation is that the fraction of the pool of integrated HIV-1 proviruses capable of replicating may be considerably less than the 12% currently noted in the literature.
AIDS (London, England) 01/2014; · 6.56 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The optimal individualized selection of antiretroviral drugs in resource-limited settings is challenging because of the limited availability of drugs and genotyping. Here we describe the development of the latest computational models to predict the response to combination antiretroviral therapy without a genotype, for potential use in such settings.
Random forest models were trained to predict the probability of a virological response to therapy (<50 copies HIV RNA/mL) following virological failure using the following data from 22 567 treatment-change episodes including 1090 from southern Africa: baseline viral load and CD4 cell count, treatment history, drugs in the new regimen, time to follow-up and follow-up viral load. The models were assessed during cross-validation and with an independent global test set of 1000 cases including 100 from southern Africa. The models' accuracy [area under the receiver-operating characteristic curve (AUC)] was evaluated and compared with genotyping using rules-based interpretation systems for those cases with genotypes available.
The models achieved AUCs of 0.79-0.84 (mean 0.82) during cross-validation, 0.80 with the global test set and 0.78 with the southern African subset. The AUCs were significantly lower (0.56-0.57) for genotyping.
The models predicted virological response to HIV therapy without a genotype as accurately as previous models that included a genotype. They were accurate for cases from southern Africa and significantly more accurate than genotyping. These models will be accessible via the online treatment support tool HIV-TRePS and have the potential to help optimize antiretroviral therapy in resource-limited settings where genotyping is not generally available.
Journal of Antimicrobial Chemotherapy 11/2013; · 5.34 Impact Factor