26 research outputs found

    Persistent homology to analyse 3D faces and assess body weight gain

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    In this paper, we analyse patterns in face shape variation due to weight gain. We propose the use of persistent homology descriptors to get geometric and topological information about the configuration of anthropometric 3D face landmarks. In this way, evaluating face changes boils down to comparing the descriptors computed on 3D face scans taken at different times. By applying dimensionality reduction techniques to the dissimilarity matrix of descriptors, we get a space in which each face is a point and face shape variations are encoded as trajectories in that space. Our results show that persistent homology is able to identify features which are well related to overweight and may help assessing individual weight trends. The research was carried out in the context of the European project SEMEOTICONS, which developed a multisensory platform which detects and monitors over time facial signs of cardio-metabolic risk

    Banach Poisson–Lie Groups and Bruhat–Poisson Structure of the Restricted Grassmannian

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    Targeting Ikaros and Aiolos with pomalidomide fails to reactivate or induce apoptosis of the latent HIV reservoir

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    HIV persists in people living with HIV (PLHIV) on antiretroviral therapy (ART) in long-lived and proliferating latently infected CD4+ T cells that selectively express pro-survival proteins, including the zinc finger proteins, Ikaros and Aiolos. In this study, we investigated whether pomalidomide, an immunomodulatory agent that induces degradation of Ikaros and Aiolos, could increase the death of HIV-infected cells and/or reverse HIV latency. Using an in vitro model of CD4+ T cells infected with a green fluorescent protein (GFP) reporter virus, pomalidomide increased the expression of the pro-survival protein B cell lymphoma (Bcl)-2 and did not increase apoptosis of GFP+ HIV productively infected CD4+ T cells. Pomalidomide also increased the expression of CD155 and UL16-binding protein (ULBP) stress proteins on GFP+ HIV productively infected CD4+ T cells, but this did not translate to enhanced clearance following co-culture with a natural killer (NK) cell line. Using CD4+ T cells from PLHIV on ART, pomalidomide ex vivo activated memory CD4+ T cells resulting in elevated HLA-DR expression and induced CD4+ T cell proliferation but only in the presence of T cell receptor stimulation with anti-CD3 and anti-CD28. There was no effect on cell-associated HIV RNA or the frequency of intact HIV DNA. In conclusion, despite an increase in stress protein expression, promoting Ikaros and Aiolos degradation in CD4+ T cells using pomalidomide did not directly induce apoptosis of HIV-infected cells or induce HIV latency reversal.IMPORTANCEPeople living with HIV (PLHIV) require lifelong antiretroviral therapy (ART) due to the persistence of latently infected cells. The zinc finger proteins, Ikaros and Aiolos, have recently been implicated in promoting the persistence of latently infected cells. In this study, we investigated the effects of pomalidomide, an immunomodulatory imide drug that induces the degradation of Ikaros and Aiolos, on HIV latency reversal and death of infected cells. Using CD4+ T cells from people living with HIV on suppressive antiretroviral therapy, as well as an in vitro model of productive HIV infection, we found that pomalidomide induced T cell activation and expression of stress proteins but no evidence of latency reversal or selective death of infected cells

    Adaptation of the intact proviral DNA assay to a nanowell-based digital PCR platform

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    Quantification of intact proviruses is a critical measurement in HIV cure studies both in vitro and in vivo. The widely adopted 'intact proviral DNA assay' (IPDA), designed to discriminate and quantify genetically intact HIV proviruses based on detection of two HIV sequence-specific targets, was originally validated using Bio-Rad's droplet digital PCR technology (ddPCR). Despite its advantages, ddPCR is limited in multiplexing capability (two-channel) and is both labor- and time intensive. To overcome some of these limitations, we utilized a nanowell-based digital PCR platform (dPCR, QIAcuity from Qiagen) which is a fully automated system that partitions samples into nanowells rather than droplets. In this study we adapted the IPDA assay to the QIAcuity platform and assessed its performance relative to ddPCR. The dPCR could differentiate between intact, 5' defective and 3' defective proviruses and was sensitive to single HIV copy input. We found the intra-assay and inter-assay variability was within acceptable ranges (with coefficient of variation at or below 10%). When comparing the performance of the IPDA in ex vivo CD4+ T cells from people with HIV on antiretroviral therapy, there was a strong correlation in the quantification of intact (rs = 0.93; p < 0.001) and 3' defective proviruses (rs = 0.96; p < 0.001) with a significant but less strong correlation for 5' defective proviruses (rs = 0.7; p = 0.04). We demonstrate that the dPCR platform enables sensitive and accurate quantification of genetically intact and defective proviruses similar to the ddPCR system but with greater speed and efficiency. This flexible system can be further optimized in the future, to detect up to 5 targets, enabling a more precise detection of intact and potentially replication-competent proviruses

    Longitudinal analysis of subtype C envelope tropism for memory CD4<SUP>+</SUP>T cell subsets over the first 3 years of untreated HIV-1 infection

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    BACKGROUND: HIV-1 infects a wide range of CD4+ T cells with different phenotypic properties and differing expression levels of entry coreceptors. We sought to determine the viral tropism of subtype C (C-HIV) Envelope (Env) clones for different CD4+ T cell subsets and whether tropism changes during acute to chronic disease progression. HIV-1 envs were amplified from the plasma of five C-HIV infected women from three untreated time points; less than 2 months, 1-year and 3-years post-infection. Pseudoviruses were generated from Env clones, phenotyped for coreceptor usage and CD4+ T cell subset tropism was measured by flow cytometry. RESULTS: A total of 50 C-HIV envs were cloned and screened for functionality in pseudovirus infection assays. Phylogenetic and variable region characteristic analysis demonstrated evolution in envs between time points. We found 45 pseudoviruses were functional and all used CCR5 to mediate entry into NP2/CD4/CCR5 cells. In vitro infection assays showed transitional memory (TM) and effector memory (EM) CD4+ T cells were more frequently infected (median: 46% and 25% of total infected CD4+ T cells respectively) than naïve, stem cell memory, central memory and terminally differentiated cells. This was not due to these subsets contributing a higher proportion of the CD4+ T cell pool, rather these subsets were more susceptible to infection (median: 5.38% EM and 2.15% TM cells infected), consistent with heightened CCR5 expression on EM and TM cells. No inter- or intra-participant changes in CD4+ T cell subset tropism were observed across the three-time points. CONCLUSIONS: CD4+ T cell subsets that express more CCR5 were more susceptible to infection with C-HIV Envs, suggesting that these may be the major cellular targets during the first 3 years of infection. Moreover, we found that viral tropism for different CD4+ T cell subsets in vitro did not change between Envs cloned from acute to chronic disease stages. Finally, central memory, naïve and stem cell memory CD4+ T cell subsets were susceptible to infection, albeit inefficiently by Envs from all time-points, suggesting that direct infection of these cells may help establish the latent reservoir early in infection

    HIV DNA persists in hepatocytes in people with HIV-hepatitis B co-infection on antiretroviral therapy

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    BACKGROUND: HIV can infect multiple cells in the liver including hepatocytes, Kupffer cells and infiltrating T cells, but whether HIV can persist in the liver in people with HIV (PWH) on suppressive antiretroviral therapy (ART) remains unknown. METHODS: In a prospective longitudinal cohort of PWH and hepatitis B virus (HBV) co-infection living in Bangkok, Thailand, we collected blood and liver biopsies from 18 participants prior to and following ART and quantified HIV and HBV persistence using quantitative (q)PCR and RNA/DNAscope. Antiretroviral (ARV) drug levels were quantified using mass spectroscopy. FINDINGS: In liver biopsies taken prior to ART, HIV DNA and HIV RNA were detected by qPCR in 53% (9/17) and 47% (8/17) of participants respectively. Following a median ART duration of 3.4 years, HIV DNA was detected in liver in 61% (11/18) of participants by either qPCR, DNAscope or both, but only at very low and non-quantifiable levels. Using immunohistochemistry, HIV DNA was observed in both hepatocytes and liver infiltrating CD4+ T cells on ART. HIV RNA was not detected in liver biopsies collected on ART, by either qPCR or RNAscope. All ARVs were clearly detected in liver tissue. INTERPRETATION: Persistence of HIV DNA in liver in PWH on ART represents an additional reservoir that warrants further investigation. FUNDING: National Health and Medical Research Council of Australia (Project Grant APP1101836, 1149990, and 1135851); This project has been funded in part with federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. 75N91019D00024

    HIV transcription persists in the brain of virally suppressed people with HIV

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    HIV persistence in the brain is a barrier to cure, and potentially contributes to HIV-associated neurocognitive disorders. Whether HIV transcription persists in the brain despite viral suppression with antiretroviral therapy (ART) and is subject to the same blocks to transcription seen in other tissues and blood, is unclear. Here, we quantified the level of HIV transcripts in frontal cortex tissue from virally suppressed or non-virally suppressed people with HIV (PWH). HIV transcriptional profiling of frontal cortex brain tissue (and PBMCs where available) from virally suppressed (n = 11) and non-virally suppressed PWH (n = 13) was performed using digital polymerase chain reaction assays (dPCR). CD68+ myeloid cells or CD3+ T cells expressing HIV p24 protein present in frontal cortex tissue was detected using multiplex immunofluorescence imaging. Frontal cortex brain tissue from PWH had HIV TAR (n = 23/24) and Long-LTR (n = 20/24) transcripts. Completion of HIV transcription was evident in brain tissue from 12/13 non-virally suppressed PWH and from 5/11 virally suppressed PWH, with HIV p24+CD68+ cells detected in these individuals. While a block to proximal elongation was present in frontal cortex tissue from both PWH groups, this block was more extensive in virally suppressed PWH. These findings suggest that the brain is a transcriptionally active HIV reservoir in a subset of virally suppressed PWH
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