The HIV-1 pandemic is a significant challenge to the field of medicine. Despite advancements in antiretroviral (ART) development, 38 million people worldwide still live with this disease without a cure. A significant barrier to the eradication of HIV-1 lies in the persistently latent pool that establishes early in the infection.
View Article and Find Full Text PDFA unique population of HIV-1 infected individuals can control infection without antiretroviral therapy. These individuals fall into a myriad of categories based on the degree of control (low or undetectable viral load), the durability of control over time and the underlying mechanism (i.e.
View Article and Find Full Text PDFModifications in chromatin structure are traditionally monitored by biochemical assays that provide average measurements of static events in a population of cells. Microscopy provides a method by which single cells or nuclei can be observed. Traditionally, microscopy has been used to image the nucleus by the application of immunostaining to chemically fixed samples or the use of exogenously expressed fluorescent proteins.
View Article and Find Full Text PDFDespite antiretroviral therapy human immunodeficiency virus type-1 (HIV-1) infection results in neuroinflammation of the central nervous system that can cause HIV-associated neurocognitive disorders (HAND). The molecular mechanisms involved in the development of HAND are unclear, however, they are likely due to both direct and indirect consequences of HIV-1 infection and inflammation of the central nervous system. Additionally, opioid abuse in infected individuals has the potential to exacerbate HIV-comorbidities, such as HAND.
View Article and Find Full Text PDFAntiretroviral therapy (ART) lowers human immunodeficiency virus type 1 (HIV-1) viral load to undetectable levels, but does not eliminate the latent reservoir. One of the factors controlling the latent reservoir is transcriptional silencing of the integrated HIV-1 long terminal repeat (LTR). The molecular mechanisms that control HIV-1 transcription are not completely understood.
View Article and Find Full Text PDFChemoresistance is one of the leading causes of mortality in breast cancer (BC). Understanding the molecules regulating chemoresistance is critical in order to combat chemoresistant BC. Drug efflux pump ABCB1 is overexpressed in chemoresistant neoplasms where it effluxes various chemotherapeutic agents from cells.
View Article and Find Full Text PDFTriple Negative Breast Cancer (TNBC), the most aggressive subtype of breast cancer, is characterized by the absence of hormone receptors usually targeted by hormone therapies like Tamoxifen. Because therapy success and survival rates for TNBC lag far behind other breast cancer subtypes, there is significant interest in developing novel anti-TNBC agents that can target TNBC specifically, with minimal effects on non-malignant tissue. To this aim, our study describes the anti-TNBC effect of strictinin, an ellagitanin previously isolated from Myrothamnus flabellifolius.
View Article and Find Full Text PDFDespite numerous recent advances in imaging technologies, one continuing challenge for cell biologists and microscopists is the visualization and measurement of endogenous proteins as they function within living cells. Achieving this goal will provide a tool that investigators can use to associate cellular outcomes with the behavior and activity of many well-studied target proteins. Here, we describe the development of a plasmid-based fluorescent biosensor engineered to measure the location and activity of matrix metalloprotease-14 (MMP14).
View Article and Find Full Text PDFChromatin modification is traditionally assessed in biochemical assays that provide average measurements of static events given that the analysis requires components from many cells. Microscopy can visualize single cells, but the cell body and organelles can hamper staining and visualization of the nucleus. Normally, chromatin is visualized by immunostaining a fixed sample or by expressing exogenous fluorescently tagged proteins in a live cell.
View Article and Find Full Text PDFThe ongoing Zika virus epidemic in the Americas and the observed association with both fetal abnormalities (primary microcephaly) and adult autoimmune pathology (Guillain-Barré syndrome) has brought attention to this neglected pathogen. While initial case studies generated significant interest in the Zika virus outbreak, larger prospective epidemiology and basic virology studies examining the mechanisms of Zika viral infection and associated pathophysiology are only now starting to be published. In this review, we analyze Zika fetal neuropathogenesis from a comparative pathology perspective, using the historic metaphor of "TORCH" viral pathogenesis to provide context.
View Article and Find Full Text PDFBackground: Long term infection with HIV-1, even in the context of therapy, leads to chronic health problems including an array of neurocognitive dysfunctions. The viral Tat protein has previously been implicated in neuropathogenesis through its effect on astrocytes. Tat has also been shown to inhibit the biogenesis of miRNAs by inhibiting the activity of the cellular Dicer protein in an RNA dependent fashion.
View Article and Find Full Text PDFEnteric dysbiosis is a characteristic feature of progressive human immunodeficiency virus type 1 (HIV-1) infection but has not been observed in simian immunodeficiency virus (SIVmac)-infected macaques, including in animals with end-stage disease. This has raised questions concerning the mechanisms underlying the HIV-1 associated enteropathy, with factors other than virus infection, such as lifestyle and antibiotic use, implicated as playing possible causal roles. Simian immunodeficiency virus of chimpanzees (SIVcpz) is also associated with increased mortality in wild-living communities, and like HIV-1 and SIVmac, can cause CD4 T cell depletion and immunodeficiency in infected individuals.
View Article and Find Full Text PDFHIV-1 infection results in a chronic illness because long-term highly active antiretroviral therapy can lower viral titers to an undetectable level. However, discontinuation of therapy rapidly increases virus burden. Moreover, patients under highly active antiretroviral therapy frequently develop various metabolic disorders, neurocognitive abnormalities, and cardiovascular diseases.
View Article and Find Full Text PDFThe viral accessory protein Vpx, expressed by certain simian and human immunodeficiency viruses (SIVs and HIVs), is thought to improve viral infectivity of myeloid cells. We infected 35 Asian macaques and African green monkeys with viruses that do or do not express Vpx and examined viral targeting of cells in vivo. While lack of Vpx expression affected viral dynamics in vivo, with decreased viral loads and infection of CD4⁺ T cells, Vpx expression had no detectable effect on infectivity of myeloid cells.
View Article and Find Full Text PDFA major barrier to the elimination of HIV-1 infection is the presence of a pool of long-lived, latently infected CD4+ memory T-cells. The search for treatments to re-activate latent HIV to aid in clearance is hindered by the incomplete understanding of the mechanisms that lead to transcriptional silencing of viral gene expression in host cells. Here we identify a previously unknown role for RUNX1 in HIV-1 transcriptional latency.
View Article and Find Full Text PDFQuantitative PCR (qPCR) provides a robust method for quantifying DNA species. By combining modern qPCR techniques with the isolation of small RNA, the polyadenylation of the RNA, and the use of reverse transcriptase to create miRNA derived cDNA, it is now possible to use qPCR to quantify miRNA. This method is scalable and provides a useful addition to the retrovirologists' toolbox.
View Article and Find Full Text PDFHIV-1 and HTLV-1 can infect CD4+ T cells and can co-infect the same individual. In principle, it is possible that both viruses can infect the same CD4+ T cells in dually infected persons. Currently, how efficiently HTLV-1 and HIV-1 co-infects the same cell and the full extent of their biological interactions are not well-understood.
View Article and Find Full Text PDFThe encoding of microRNAs in retroviral genomes has remained a controversial hypothesis despite significant supporting evidence in recent years. A recent publication demonstrating the production of functional miRNAs from the retrovirus bovine leukemia virus adds further credence to the fact that retroviruses do indeed encode their own miRNAs. Here we comment on the importance of this paper to the field, as well as examine the other known examples of miRNAs encoded by RNA viruses.
View Article and Find Full Text PDFPotent anti-retroviral therapy has transformed HIV-1 infection into a chronic manageable disease; however, drug resistance remains a common problem that limits the effectiveness and clinical benefits of this type of treatment. The discovery of viral reservoirs in the body, in which HIV-1 may persist, has helped to explain why therapeutic eradication of HIV-1 has proved so difficult. In the current study, we utilized a combination of structure-based analysis of cyclin/CDK complexes with our previously published Tat peptide derivatives.
View Article and Find Full Text PDFAutophagy, a general homeostatic process for degradation of cytosolic proteins or organelles, has been reported to modulate the replication of many viruses. The role of autophagy in human T-cell leukemia virus type 1 (HTLV-1) replication has, however, been uncharacterized. Here, we report that HTLV-1 infection increases the accumulation of autophagosomes and that this accumulation increases HTLV-1 production.
View Article and Find Full Text PDFRNAi plays important roles in many biological processes, including cellular defense against viral infection. Components of the RNAi machinery are widely conserved in plants and animals. In mammals, microRNAs (miRNAs) represent an abundant class of cell encoded small noncoding RNAs that participate in RNAi-mediated gene silencing.
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