From despair to hope studies in HIV and tuberculosis 1992-2011

Includes abstract. Includes bibliographical references

Chapter 11: Genome-Wide Association Studies

Genome-wide association studies (GWAS) have evolved over the last ten years into a powerful tool for investigating the genetic architecture of human disease. In this work, we review the key concepts underlying GWAS, including the architecture of common diseases, the structure of common human genetic variation, technologies for capturing genetic information, study designs, and the statistical methods used for data analysis. We also look forward to the future beyond GWAS

Characterizing the neurological impact of acute HIV infection and its outcomes after immediate initiation of antiretroviral therapy

HIV invades the central nervous system (CNS) during early infection and contributes to neurocognitive impairment during chronic infection. This thesis aims to investigate the neurological impact of acute HIV infection (AHI) and its outcomes after immediate initiation of antiretroviral therapy (ART). Section 1 of this thesis is an introduction to the persistence of HIV-associated neurocognitive disorder in the ART era, highlighting the need to study AHI to understand HIV neuropathogenesis. The main body of the thesis describes the outcomes of the RV254 Thai AHI cohort, in which all participants were enrolled during AHI and initiated ART within days after the diagnosis. Section 2 focuses on the findings during AHI, examining the determinant of HIV-1 RNA level in cerebrospinal fluid (CSF), the impact of concomitant syphilis, and the safety of performing lumbar punctures during AHI. Section 3 discusses the longitudinal outcomes of RV254 participants after ART, presenting their 6-year neurocognitive trajectory, the neuropsychological impact of switching from a Efavirenz-based ART to a Dolutegravir-based ART regimen, and the rare detection of HIV-1 RNA in CSF during plasma HIV-1 suppression (CSF HIV-1 escape). Section 4 explores the implications of CNS in HIV cure research. The findings suggest that HIV-1 invades the CNS during acute infection and causes abnormal neurological signs, neurocognitive dysfunction and depressive mood. Yet, prompt initiation of ART during AHI could reverse these abnormalities - RV254 participants on stable ART are generally free from neuropsychiatric complications frequently seen in other HIV-positive populations, highlighting the benefit of early ART in HIV infection

Antiretroviral drugs differentially modulate glucocorticoid activity via the glucocorticoid receptor in vitro

Concurrent use of anti-retroviral drugs (ARVs) and progestin-based hormonal contraceptives is widespread. During times of stress and during glucocorticoid (GC) therapy, intracellular ARVs are in the presence of high concentrations of GCs, which regulate all aspects of immunity and inflammation via the glucocorticoid receptor (GR). However, the reciprocal modulation of ARV and steroid intracellular functions is relatively unexplored. In this study, the effects of the ARVs tenofovir disoproxil fumarate (TDF), dapivirine (DPV), and maraviroc (MVC) on activation of the GR and GR-regulated mRNA expression were investigated, in the absence and presence of select GR ligands. The effects of TDF and DPV on GR protein levels and phosphorylation were also determined. The inhibitory activity of these ARVs on HIV-1 infection in the presence of the progestins medroxyprogesterone acetate (MPA) and levonorgestrel (LNG), and a GR agonist, dexamethasone (DEX) was also assessed. This study shows that (0.01 nM-10 µM) TDF, DPV and MVC do not transactivate reporter gene expression via the unliganded GR exogenously expressed in the steroid receptor-deficient U2OS human osteosarcoma cell line, or alter the reporter gene transcriptional activity of (100 nM) MPA or LNG via the GR in these cells. However, (1 µM) TDF and DPV modulate the reporter gene transcriptional efficacy of (0.01 nM-10 µM) DEX via the GR. In the U2OS cell line model, (1 µM) TDF, but not DPV significantly decreased (1µM and 10µM) DEX-induced mRNA expression of the anti-inflammatory glucocorticoid-induced leucine zipper (GILZ) gene. TDF also appeared to decrease (1 µM) cortisol (CORT)- and MPA-induced GILZ mRNA expression. This may be mediated by the apparent increase in (100 nM and 1µM) DEXinduced phosphorylation at Serine 226 on the GR, observed in the presence of (1µM) TDF in this study. DPV and TDF (at 1µM) did not significantly alter GR protein levels, or cell-viability in the absence and presence of (100 nM) DEX, CORT or MPA in U2OS cells. However, (1 µM) DPV and TDF alone, significantly altered cell viability in peripheral blood mononuclear cells (PBMCs). In PBMCs, (1 µM) TDF, MVC and DPV alone altered basal GILZ mRNA expression and had variable, donor-specific effects on interleukin (IL)-6, IL-8, and interferon (IFN)-γ gene expression. In PBMCs from some of the nine donors tested, these ARVs had proinflammatory effects which may undermine their efficacy at preventing HIV-1 acquisition in pre-exposure prophylaxis products. Moreover, the ARVs proinflammatory effects may negatively impact HIV-1 disease progression and increase the risk of non-AIDS mortality in individuals using the ARVs therapeutically. Neither (1 µM) DPV, TDF nor MVC significantly altered the effects of (100 nM) DEX on the immunomodulatory genes assessed in PBMCs. DEX, MPA and LNG (at 100 nM) did not affect the anti-HIV-1 activity of the ARVs (at 1 µM) in PBMCs from the majority of the three donors tested in this study. Taken together, the results show that ARVs can modulate GR activity in an ARV-, steroid-, gene- and cell-specific manner, while the steroids investigated did not modulate ARV anti-HIV-1 activity

HIV-1 infected women in Europe.

This thesis aims to describe the wider impact of HIV infection on reproductive choices and pregnancy outcomes in HIV-infected women in Europe. Characteristics of 403 HIV-infected women enrolled in a survey on reproductive choices are described. There was no evidence to suggest HIV-infected women have problems to conceive maternal well-being, an uninfected partner and not having children yet were strongly associated with being pregnant. Results from a laboratory-based descriptive study, including 57 pregnant women provide a biological explanation for HAART-associated premature delivery in HIV- infected women cytokine patterns (IL2 and IL10) were analysed over three trimesters of pregnancy and in relation to gestational age at delivery. Intrauterine growth (femur length, head and abdominal circumference) of infants born to 316 HIV infected mothers, compared to an uninfected population is reported. The average z-score of head circumference and femur length in HIV- infected women was below the reference (32th centile and 15th centile respectively), but the average z-score for abdominal circumference differs only marginally (49th centile). In order to add one more piece of information in relation to maternal treatment and gestational age at delivery, birth-weight from a large European cohort was analysed and compared to the British standard. Mean z-scores decreased from - 0.10 (46th centile), -0.13 (45th centile) and -0.30 (37th centile) throughout gestation indicating that children born to HIV infected mothers became smaller towards the end of pregnancy, and premature delivery in HAART-treated mothers was not associated to fetal distress. Complications after delivery according to infection status of the mother and mode of delivery, were reported from a total of 250 HIV-status matched pairs delivered vaginally and from 158 by elective caesarean section. HIV-infected women suffered an increased risk of minor complications, but major complications only occurred in the caesarean section arm

Immunological characterization of the HIV-tuberculosis associated immune reconstitution inflammatory syndrome

While the integration of anti-TB and cART therapies is associated with substantial clinical improvement in the majority of patients, HIV-Tuberculosis associated Immune Reconstitution Inflammatory Syndrome (TB-IRIS) has been shown to occur in a significant subset of these patients. TB-IRIS is an inflammatory complication of the combined treatments for HIV-1 and tuberculosis, which is being reported increasingly, particularly in areas endemic to both diseases. This work aimed to characterise the immunopathogenesis of paradoxical HIV-Tuberculosis associated immune reconstitution inflammatory syndrome