Biology subjects

Ndhlovu, L. C.

Publications and source records attributed to Ndhlovu, L. C..

8 recordsLinked to original sources

bioRxiv2025

Antiviral and Anti-inflammatory Effects of Cannabidiol in HIV/SIV Infection

Persistent reservoirs and chronic immune activation are hallmarks of HIV, despite the effectiveness of antiretroviral therapy (ART) in suppressing viral replication. Here, we use rhesus macaques and primary and induced pluripotent stem cell (iPSC)-derived human immune cells to evaluate the virologic and immunologic consequences of cannabidiol (CBD) exposure during HIV/SIV infection. We show that CBD, in the absence of ART, suppresses viral replication and establishment of the viral reservoir to levels comparable with first-line therapies during acute SIV infection of rhesus macaques. This antiviral effect of CBD extended to in vitro HIV infection of human macrophages, T cells, and microglia. Immunologically, we observe CBD slowed CD4+ T cell decline and polarization, decreased CD14+CD16+ monocyte expansion, and reduced interferon-inducible cytokine release in rhesus macaques. We identify comparable effects on cytokine production with in vitro CBD treatment of human macrophages, T cells, and microglia. Importantly, we find CBD inhibits cytokines only when an immune response is elicited by HIV, suggesting it is not broadly immunosuppressive. Finally, we determine CBD regulates endocannabinoid receptors, modulators, and transporters and inhibits NF-{kappa}b and STAT1 activation when mediating its antiviral and anti-inflammatory effects. These findings show beneficial effects of CBD in laboratory models of untreated HIV, thus placebo-controlled clinical trials to evaluate the safety and effectiveness of adjunctive CBD use with ART is warranted.

microbiology↗

bioRxiv2024

Single-cell analyses reveal that monocyte gene expression profiles influence HIV-1 reservoir size in acutely treated cohorts

Elimination of latent HIV-1 is a major goal of AIDS research but the host factors determining the size of these reservoirs are poorly understood. Here, we investigated whether differences in host gene expression modulate the size of the HIV-1 reservoir during suppressive ART. Peripheral blood mononuclear cells (PBMC) from fourteen individuals initiating ART during acute infection who demonstrated effective viral suppression but varying magnitude of total HIV-1 DNA were characterized by single-cell RNA sequencing (scRNA-seq). Differentially expressed genes and enriched pathways demonstrated increased monocyte activity in participants with undetectable HIV-1 reservoirs. IL1B expression in CD14+ monocytes showed the greatest fold difference. The inverse association of IL1B with reservoir size was validated in an independent cohort comprised of 38 participants with different genetic backgrounds and HIV-1 subtype infections, and further confirmed with intact proviral DNA assay (IPDA(R)) measurements of intact HIV-1 proviruses in a subset of the samples. Modeling interactions with cell population frequencies showed that monocyte IL1B expression associated inversely with reservoir size in the context of higher frequencies of central memory CD4+ T cells, implicating an indirect effect of IL1B via the cell type well established to be a reservoir for persistent HIV-1. Signatures consisting of co-expressed genes including IL1B were highly enriched in the "TNF signaling via NF-{kappa}B" geneset. Functional analyses in cell culture revealed that IL1B activates NF-{kappa}B, thereby promoting productive HIV-1 infection while simultaneously suppressing viral spread, suggesting a natural latency reversing activity to deplete the reservoir in ART treated individuals. Altogether, unbiased high throughput scRNA-seq analyses revealed that monocyte IL1B variation could decrease HIV-1 proviral reservoirs in individuals initiating ART during acute infection.

immunology↗

bioRxiv2024

A Transcriptional Signature of Induced Neurons Differentiates Virologically Suppressed People Living With HIV from People Without HIV

Neurocognitive impairment is a prevalent and important co-morbidity in virologically suppressed people living with HIV (PLWH), yet the underlying mechanisms remain elusive and treatments lacking. Here, we explored for the first time, use of participant-derived directly induced neurons (iNs) to model neuronal biology and injury in PLWH. iNs retain age-and disease-related features of the donors, providing unique opportunities to reveal novel aspects of neurological disorders. We obtained primary dermal fibroblasts from six virologically suppressed PLWH (range: 27 - 64 years, median: 53); 83% Male; 50% White) and seven matched people without HIV (PWOH) (range: 27 - 66, median: 55); 71% Male; 57% White). iNs were generated using transcription factors NGN2 and ASCL1, and validated by immunocytochemistry and single-cell-RNAseq. Transcriptomic analysis using bulk-RNAseq identified 29 significantly differentially expressed genes between iNs from PLWH and PWOH. Of these, 16 genes were downregulated and 13 upregulated in PLWH iNs. Protein-protein interaction network mapping indicates that iNs from PLWH exhibit differences in extracellular matrix organization and synaptic transmission. IFI27 was upregulated in iNs from PLWH, which complements independent post-mortem studies demonstrating elevated IFI27 expression in PLWH-derived brain tissue, indicating that iN generation reconstitutes this pathway. Finally, we observed that expression of the FOXL2NB-FOXL2-LINC01391 genome locus is reduced in iNs from PLWH and negatively correlates with neurocognitive impairment. Thus, we have identified an iN gene signature of HIV through direct reprogramming of skin fibroblasts into neurons revealing novel mechanisms of neurocognitive impairment in PLWH. One sentence summaryDirect reprogramming of skin fibroblasts into neurons reveals unique gene signatures indicative of HIV infection in the context of viral suppression.

neuroscience↗

bioRxiv2023

Multiplex analysis of cytokines and chemokines in persons aging with or without HIV

People with HIV (PWH) on combined antiretroviral therapy (cART) are living longer lives due to modern cART advances and increased routine medical care. The full landscape of aging with HIV is unclear; given that HIV emerged relatively recently in human history and initially had a high mortality rate, there has not been a substantially aged population to evaluate. In the present study, we set out to perform high throughput plasma analyte profiling by multiplex analysis, focusing on various T helper (Th)-related cytokines, chemokines, and pro- and anti-inflammatory cytokines. The primary goals being to provide reference ranges of these analytes for aging PWH cohorts, as well as testing the utility of high throughput multiplex plasma assays. The cohort used in this study was comprised of age-matched healthy donors (aged 32.6-73.5), PWH on cART (aged 26.7-60.2), and viremic PWH (aged 27.5-59.4). The patients in each group were then stratified across the age span to examine age-related impacts of these plasma biomarkers. Our results largely indicate feasibility of plasma analyte monitoring by multiplex and demonstrate a high degree of person-to-person variability regardless of age and HIV status. Nonetheless, we find multiple associations with age, duration of known infection, and viral load, all of which appear to be driven by either prolonged HIV disease progression or long-term use of cART.

immunology↗

bioRxiv2022

Host Immunity to Mycobacterium tuberculosis Infection is Similar in Simian Immunodeficiency Virus (SIV)-infected, Antiretroviral Therapy-treated and SIV-naïve Juvenile Macaques

Pre-existing HIV infection increases tuberculosis (TB) risk in children. Antiretroviral therapy (ART) reduces, but does not abolish, this risk in children with HIV. The immunologic mechanisms involved in TB progression in both HIV-naive and HIV-infected children have not been explored. Much of our current understanding is based on human studies in adults and adult animal models. In this study, we sought to model childhood HIV/Mycobacterium tuberculosis (Mtb) coinfection in the setting of ART and characterize T cells during TB progression. Macaques equivalent to 4-8 year-old children were intravenously infected with SIVmac239M, treated with ART three months later, and coinfected with Mtb three months after initiating ART. SIV-naive macaques were similarly infected with Mtb alone. TB pathology and total Mtb burden did not differ between SIV-infected, ART-treated and SIV-naive macaques, although lung Mtb burden was lower in SIV-infected, ART-treated macaques. No major differences in frequencies of CD4+ and CD8+ T cells and unconventional T cell subsets (V{gamma}9+ {gamma}{delta} T cells, MAIT cells, and NKT cells) in airways were observed between SIV-infected, ART-treated and SIV-naive macaques over the course of Mtb infection, with the exception of CCR5+ CD4+ and CD8+ T cells which were slightly lower. CD4+ and CD8+ T cell frequencies did not differ in the lung granulomas obtained at necropsy, nor did they differ in the frequency of immune checkpoint and proliferative markers. Thus, ART treatment of juvenile macaques, three months after SIV infection, resulted in similar progression of Mtb and T cell responses compared to Mtb in SIV-naive macaques.

immunology↗

bioRxiv2022

Human Galectin-9 Promotes the Expansion of HIV Reservoirs in vivo in Humanized Mice

ObjectiveThe human endogenous {beta}-galactoside-binding protein Galectin-9 (Gal-9) reactivates latently HIV-infected cells, which may allow for immune-mediated clearance of these cells. However, Gal-9 also activates T cell Receptor (TCR) signaling pathways, which could negatively affect HIV persistence by promoting T cell expansion and chronic activation/exhaustion. This potential "double-edged sword" effect of Gal-9 during HIV infection raises the question of the overall beneficial versus detrimental impact of Gal-9 on HIV persistence in vivo. DesignWe used the BLT (bone marrow, liver, thymus) humanized mouse model to evaluate the overall impact of Gal-9 on HIV persistence in vivo during antiretroviral therapy (ART). MethodsTwo independent cohorts of BLT mice with high human immune reconstitution were infected with HIV, placed on ART, and then treated with either recombinant human Gal-9 or PBS during ART suppression. Plasma viral loads and levels of tissue-associated HIV DNA and RNA were measured by qPCR. Markers of T cell activation/exhaustion were measured by flow cytometry, and plasma markers of inflammation were measured by multiplex cytokine arrays. ResultsGal-9 treatment was tolerable in ART-suppressed humanized mice and did not significantly induce plasma markers of inflammation or T cell markers of activation/exhaustion. However, Gal-9 treatment during ART significantly increased levels of tissue-associated HIV DNA and RNA compared to controls (P=0.0007 and P=0.011, respectively, for cohort I and P=0.002 and P=0.005, respectively, for cohort II). ConclusionsOur study highlights the overall adverse effects of Gal-9 on HIV persistence and the potential need to block Gal-9 interactions during ART-suppressed HIV infection.

microbiology↗

bioRxiv2020

Comparative in vitro transcriptomic analyses of COVID-19 candidate therapy hydroxychloroquine suggest limited immunomodulatory evidence of SARS-CoV-2 host response genes.

Hydroxychloroquine (HCQ) has emerged as a potential and controversial antiviral candidate therapy for COVID-19. While many clinical trials are underway to test the efficacy of HCQ as a treatment for COVID-19, underlying mechanisms of HCQ in the setting of COVID-19 remain unclear. Hence, we examined differential gene expression signatures of HCQ exposure, in vitro SARS-CoV-2 infection, and host signatures of COVID-19 in blood, bronchoalveolar lavage, and postmortem lung to evaluate whether HCQ transcriptome signatures associate with restoration of SARS-CoV-2-related host transcriptional responses. Here, we show that 24 hours of in vitro treatment of peripheral blood mononuclear cells(PBMC) with HCQ significantly impacted transcription of 16 genes involved in immune regulation and lipid metabolism. Using transcriptome data from in vitro SARS-CoV-2 infected NHBE and A549 cells and PBMC derived from confirmed COVID-19 infected patients, we determined that only 0.24% of the COVID-19 PBMC differentially expressed gene set and 0.39% of the in vitro SARS-CoV-2 cells differentially expressed gene set overlapped with HCQ-related differentially expressed genes. Moreover, we observed that HCQ treatment significantly impacted transcription of 159 genes in human primary monocyte-derived macrophages involved in cholesterol biosynthetic process and chemokine activity. Notably, when we compared the macrophage HCQ-related gene lists with genes transcriptionally altered during SARS-CoV-2 infection and in bronchoalveolar lavage of COVID-19+ patients, the CXCL6 gene was impacted in all three transcriptional signatures revealing evidence in favor of chemokine modulation. HCQ-related transcriptional changes minimally overlapped with host genes altered in postmortem lung biopsies from COVID-19 participants. These results may provide insight into the immunomodulation mechanisms of HCQ treatment in the setting of COVID-19 and suggest HCQ is not a panacea to SARS-CoV-2 infection.

immunology↗

bioRxiv2018

Anti-α4β7 therapy targets lymphoid aggregates in the gastrointestinal tract of HIV-1 infected individuals

Herein, we present the first human study of anti-4{beta}7 therapy in a cohort of HIV-1 infected subjects with mild inflammatory bowel disease. 4{beta}7+ gut homing CD4+ T cells are early viral targets and contribute to HIV-1 pathogenesis, likely by seeding the gastrointestinal (GI) tract with HIV. Although, simianized anti-4{beta}7 monoclonal antibodies (Mab) have shown promise in preventing or attenuating the disease course of SIV in Non-Human Primate studies, the mechanisms of drug action remain elusive and the impact on HIV-1 persistence remains unanswered. By sampling the immune inductive and effector sites of the GI tract, we have discovered that anti-4{beta}7 therapy led to a significant and unexpected attenuation of lymphoid aggregates, most notably in the terminal ileum. Given that lymphoid aggregates serve as important sanctuary sites for establishing and maintaining viral reservoirs, their attrition by anti-4{beta}7 therapy has important implications for HIV-1 therapeutics and eradication efforts, and defines a rational basis for the continued evaluation of anti-4{beta}7 therapy in HIV-1 infection.\n\nOne Sentence SummaryAnti-4{beta}7 integrin therapy results in attrition of lymphoid aggregates within the gastrointestinal tract of HIV-1 infected individuals

immunology↗