Project description:Background: The cellular reservoir of latent HIV infection remains the main barrier to cure this virus. Elimination of this reservoir would be possible, if molecular identity of latently infected cells were fully elucidated. Biomarkers proposed previously were able to capture only a relatively small fraction of all reservoir cells. In the present study, we set out to conduct comprehensive molecular profiling, at the protein and RNA levels, of CD4+ T cells latently infected with HIV in vitro, using liquid chromatography-mass spectrometry (LC-MS) and RNA sequencing (RNA-Seq), respectively. Protein-based methods such as quantitative proteomic profiling using LC-MS may be more beneficial due to direct transferability of results to antibody-based approaches to capture latently infected cells. Integrated analysis of proteomic and transcriptomic data adds a level of validation and increases confidence in identified biomarkers. Flow cytometry and integrated HIV DNA assay were further used to enrich for latently infected cells with antibodies against selected biomarker proteins. Results: Using quantitative proteomics, we identified a total of 10,886 proteins (peptide level FDR < 0.05), of which 673 were up- and 780 down-regulated in latently infected compared to mock-infected cells in vitro (p < 0.05). Among these proteins, 21 were dysregulated at the RNA level in the same direction. Pathway analysis identified p53, mTOR, Wnt and NOTCH signaling, demonstrating that our in vitro model reflects known mechanisms of latency establishment and maintenance. Comparison of identified proteins with other proteomics studies revealed that identified molecular signatures of latency depend on technology and cell types used; however, a subset of proteins were identified both in the present, and at least one other study. Antibodies against selected protein markers, CEACAM1 and PLXNB2, could enrich for latently infected cells from mixed cell population 3-10 fold (5.8 fold average, p < 0.001). Conclusion: Two new molecules, CEACAM1 and PLXNB2, were identified as biomarkers for HIV latency. However, the level of enrichment for latently infected cells compared to biomarkers proposed previously was not improved. These results are consistent with the idea that each proposed biomarker defines only a subset of latently infected cells, and that a combined biomarker will be required to capture or target the latent HIV reservoir represented by different cell types.
Project description:Herein expression trends of host miRNA were measured in HIV-1 latently infected and persistent replication cells, as well as the control cells. HIV-1 latency infection was established by infecting CEM-SS lymphocytes with HIV-1 Bru strain. After selection and long-term culture, the chronically infected cell showed the characteristics of latency definition: 1. The provirus was intergrated in to the host genome.2. No viral expression could be detected during culture.3 .Cell stimulators, such as TNFa,PMA, etc, reactivate the viral expression. As expected, miRNA trend was different in HIV-1 latency when compared to the control or HIV-1 replication. A subset of miRNAs is enriched in HIV-1 latency model. The observation reinforces the concept of active HIV-1 interplay with host small RNAs that modulate HIV-1 infection mode.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:Herein expression trends of host miRNA were measured in HIV-1 latently infected and persistent replication cells, as well as the control cells. HIV-1 latency infection was established by infecting CEM-SS lymphocytes with HIV-1 Bru strain. After selection and long-term culture, the chronically infected cell showed the characteristics of latency definition: 1. The provirus was intergrated in to the host genome.2. No viral expression could be detected during culture.3 .Cell stimulators, such as TNFa,PMA, etc, reactivate the viral expression. As expected, miRNA trend was different in HIV-1 latency when compared to the control or HIV-1 replication. A subset of miRNAs is enriched in HIV-1 latency model. The observation reinforces the concept of active HIV-1 interplay with host small RNAs that modulate HIV-1 infection mode. In this study, the in vitro steady cell culture was used to explore the miRNA transcription signatures in HIV-1 infection. miRNA profiles were performed and compared among normal control,HIV-1 latency and HIV-1 replication .
Project description:Despite the success of antiretroviral therapy, HIV cannot be cured because of a reservoir of latently infected cells that evades therapy. To understand the mechanisms of HIV latency, we employed an integrated single-cell RNA-seq/ATAC-seq approach to simultaneously profile the transcriptomic and epigenomic characteristics of ~125,000 latently infected primary CD4 cells after reactivation using three different latency-reversing agents.
Project description:HIV infection is not curable due to viral latency. Compelling reports studying proteins such as CD2, PD-1, LAG-3 and TIGIT suggest that there is a distinct profile of surface proteins that can be used for targeting latently infected cells. We have recently reported that glycoproteins were differentially secreted from HIV latently infected ACH-2 cells compared to the parental A3.01 cells. This observation suggests that glyco-phenotype might be different in these two cell lines. To determine the difference, the ACH-2 and A3.01 cell lines were subjected to a glycoproteomic analysis. A total number of 940 unique N-linked glycosite-containing peptides from 515 glycoproteins were identified. Among the glycoproteins, 365 and 104 were annotated as cell surface and membrane-associated proteins, respectively. Label free quantitative LC-MS/MS analysis revealed a change of 236 glycosite-containing peptides from 172 glycoproteins between the two cell lines without reactivation. Bioinformatic analysis suggests that cell adhesion, immune response, glycoprotein metabolic process, cell motion and cell activation were associated with the changed proteins. After reactivation of latency by phorbol myristate acetate (PMA), changes in glycosite-containing peptides were observed in both cell lines. Changes in 49 glycosite-containing peptides from 45 glycoproteins might be due to viral replication. The changed proteins suggest that cell migration, response to wounding and immune response were impaired in reactivated latently infected cells. Our study provides important glycoproteomic data in respect to HIV latently infected cells. Glycoproteomics merits future application using primary cells to discover reveal mechanisms in HIV pathogenesis.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.