Project description:Smoking is common in people who live with HIV infection and has significant adverse effects on HIV outcomes. The impacts of smoking on methylome has been well established in non-HIV populations. However, the smoking’s effects on host methylome in HIV-positive population has not been investigated and it is unknown if smoking-associated DNA methylation link to HIV outcomes. In this study, we applied machine learning methods selected smoking-associated DNA methylation features to predict HIV related frailty and mortality.
Project description:Smoking is common in people who live with HIV infection and has significant adverse effects on HIV outcomes. The impacts of smoking on methylome has been well established in non-HIV populations. However, the smoking’s effects on host methylome in HIV-positive population has not been investigated and it is unknown if smoking-associated DNA methylation link to HIV outcomes. In this study, we applied machine learning methods selected smoking-associated DNA methylation features to predict HIV related frailty and mortality.
Project description:Ongoing viral transcription from the reservoir of long-lived CD4+ T cells containing integrated HIV-1 DNA presents a barrier to cure and associates with poorer health outcomes for people living with HIV, including chronic immune activation and inflammation. We previously reported that didehydro-Cortistatin A (dCA), an HIV-1 Tat inhibitor, blocks HIV-1 transcription. We sought to extend this work and examine the impact of dCA on host immune CD4+ T cell transcriptional and epigenetic states. Here, we performed a comprehensive analysis of genome-wide transcriptomic and DNA methylation profiles upon long-term dCA-treatment of primary human memory CD4+ T cells. dCA prompted specific transcriptional and DNA methylation changes in cell cycle, histone, interferon-response and T cell lineage transcription factor genes, through inhibition of both HIV-1 and Mediator kinases. These alterations establish a tolerogenic Treg/Th2 phenotype, reducing viral gene expression and mitigating inflammation in primary CD4+T cells during HIV-1 infection. Additionally, dCA suppresses expression of lineage-defining transcription factors for Th17 and Th1 cells, critical HIV-1 targets and reservoirs. dCA’s benefits thus extend beyond viral transcription inhibition, modulating immune cell landscape to limit HIV-1 acquisition and inflammatory environment linked to HIV-infection.
Project description:T cell dysfunction occurs early following HIV infection, impacting the emergence of non-AIDS morbidities and limiting curative efforts. ART initiated during primary HIV infection (PHI) can reverse this dysfunction, but the extent of recovery is unknown. We studied 66 HIV-infected individuals treated from early PHI with up to three years of ART. Compared with HIV-uninfected controls, CD4 and CD8 T cells from early HIV infection were characterised by T cell activation and increased expression of the immune checkpoint receptors (ICRs) PD1, Tim-3 and TIGIT. Three years of ART lead to partial – but not complete – normalisation of ICR expression, the dynamics of which varied for individual ICRs. For HIV-specific cells, epigenetic profiling of tetramer-sorted CD8 T cells revealed that epigenetic features of exhaustion typically seen in chronic HIV infection were already present early in PHI, and that ART initiation during PHI resulted in only a partial shift of the epigenome to one with more favourable memory characteristics. These findings suggest that although ART initiation during PHI results in significant immune reconstitution, there may be only partial resolution of HIV-related phenotypic and epigenetic changes.
Project description:Cannabis use has been controversial, largely having been designated a controlled substance over the last century. The link between cannabis smoking and disease pathogenesis may best be explored through DNA methylation, an epigentic mechanism. We investigated the relationship between epigenetic age and cannabis smoking in participants within the Canadian Cohort of Obstructive Lung Disease (CanCOLD) cohort (n=93) (ClinicalTrials.gov identifier NCT00920348). Blood samples were profiled for DNA methylation using the Illumina MethylationEPIC BeadChipv1 at two separate laboratories and the blood epigenetic age of each sample was calculated using the Clock Foundation tool (https://dnamage.clockfoundation.org). An ANOVA was used to identify differences in the age acceleration residuals associated with cannabis smoking status (never, former, and current), adjusted for chronological age, sex, body mass index (BMI), batch, cigarette smoking status, and the first two principal components of blood cell proportions. Our observations indicated that current cannabis smoking and higher joint-years exposure are associated with epigenetic age acceleration; cessation, however, may help to normalize in part this age acceleration.