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BACKGROUND: In people living with HIV-HBV, liver fibrosis progression can occur even with suppressive antiretroviral therapy (ART). We investigated the relationship between liver fibrosis and biomarkers of inflammation, apoptosis, and microbial translocation. METHODS: In this observational cohort study adults living with HIV-HBV already on effective ART were recruited in Australia and Thailand and followed for 3 years including 6 monthly clinical review and blood tests and annual transient elastography. Differences in clinical and laboratory predictors of liver fibrosis progression were tested followed by regression analysis adjusted for CD4+ T-cells at study entry. A linear mixed model was fitted to longitudinal data to explore changes over time. FINDINGS: 67 participants (85% male, median age 49 y) were followed for 175 person-years. Median duration of ART was 10 years (interquartile range (IQR) 8-16 years). We found 11/59 (19%) participants during 3-years follow-up (6/100 person-years) met the primary endpoint of liver disease progression, defined as increased Metavir stage from baseline to final scan. In regression analysis, progressors compared to non-progressors had higher levels of high mobility group box 1 protein (HGMB1), (median (IQR) 3.7 (2.6-5.0) and 2.4 ng/mL (1.5-3.4) respectively, adjusted relative risk 1.47, 95% CI [1.00, 2.17]) and lower nadir CD4+ T-cell percentage (median 4% (IQR 2-8) and 11% (4-15) respectively (relative risk 0.93, 95% CI [0.88, 0.98]). INTERPRETATION: Progression in liver fibrosis occurs in people with HIV-HBV on suppressive ART. Fibrosis progression was associated with higher HMGB1 and lower percentage nadir CD4+ T-cell count, highlighting the importance of early initiation of HBV-active ART. FUNDING: This work was supported by NHMRC project grant 1101836; NHMRC practitioner fellowship 1138581 and NHMRC program grant 1149990. The funder had no role in study design, data collection, data analysis, interpretation, writing of this

BACKGROUND & AIMS: New antiviral approaches that target multiple aspects of the HBV replication cycle to improve rates of functional cure are urgently required. HBV RNA represents a novel therapeutic target. Here, we programmed CRISPR-Cas13b endonuclease to specifically target the HBV pregenomic RNA and viral mRNAs in a novel approach to reduce HBV replication and protein expression. METHODS: Cas13b CRISPR RNAs (crRNAs) were designed to target multiple regions of HBV pregenomic RNA. Mammalian cells transfected with replication competent wild-type HBV DNA of different genotypes, a HBV-expressing stable cell line, a HBV infection model and a hepatitis B surface antigen (HBsAg)-expressing stable cell line were transfected with PspCas13b-BFP (blue fluorescent protein) and crRNA plasmids, and the impact on HBV replication and protein expression was measured. Wild-type HBV DNA, PspCas13b-BFP and crRNA plasmids were simultaneously hydrodynamically injected into mice, and serum HBsAg was measured. PspCas13b mRNA and crRNA were also delivered to a HBsAg-expressing stable cell line via lipid nanoparticles and the impact on secreted HBsAg determined. RESULTS: Our HBV-targeting crRNAs strongly suppressed HBV replication and protein expression in mammalian cells by up to 96% (p <0.0001). HBV protein expression was also reduced in a HBV-expressing stable cell line and in the HBV infection model. CRISPR-Cas13b crRNAs reduced HBsAg expression by 50% (p <0.0001) in vivo. Lipid nanoparticle-encapsulated PspCas13b mRNA reduced secreted HBsAg by 87% (p = 0.0168) in a HBsAg-expressing stable cell line. CONCLUSIONS: Together, these results show that CRISPR-Cas13b can be programmed to specifically target and degrade HBV RNAs to reduce HBV replication and protein expression, demonstrating its potential as a novel therapeutic option for chronic HBV infection. IMPACT AND IMPLICATIONS: Owing to the limitations of current antiviral therapies for hepatitis B, there is an urgent need for new tre

INTRODUCTION: Antiretroviral therapy for people living with HIV-1 must be taken lifelong due to the persistence of latent virus in long-lived and proliferating CD4+ T cells. Vitamin D3 is a steroidal gene transcription regulator which exerts diverse effects on immune and epithelial cells including reductions in CD4+ T cell proliferation and improvement in gut barrier integrity. We hypothesised that a high dose of vitamin D3 would reduce the size of the HIV-1 reservoir by reducing CD4+ T cell proliferation. METHODS: We performed a randomised placebo-controlled trial evaluating the effect of 24 weeks of vitamin D3 (10,000 international units per day) on the HIV-1 reservoir and immunologic parameters in 30 adults on antiretroviral therapy; participants were followed for 12 weeks post-treatment. The primary endpoint was the effect on total HIV-1 DNA at week 24. Parameters were assessed using mixed-effects models. RESULTS: We found no effect of vitamin D3 on the change in total HIV-1 DNA from week 0 to week 24 relative to placebo. There were also no changes in integrated HIV-1 DNA, 2-long-terminal repeat (2-LTR) circles or cell-associated HIV-1 RNA. Vitamin D3 induced a significant increase in the proportion of central memory CD4+ and CD8+ T cells, a reduction in the proportion of senescent CD8+ T cells and a reduction in the natural killer cell frequency at all time points including week 36, 12 weeks after the study drug cessation. At week 36, there was a significant reduction in total HIV-1 DNA relative to placebo and persistently elevated 25-hydroxyvitamin D levels. No significant safety issues were identified. CONCLUSIONS: Vitamin D3 administration had a significant impact on the T cell differentiation but overall effects on the HIV-1 reservoir were limited and a reduction in HIV-1 DNA was only seen following cessation of the study drug. Additional studies are required to determine whether the dose and duration of vitamin D3 can be optimised to promote a continued de

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.

Here, we provide the first regional analysis of intact and defective HIV reservoirs within the brain. Brain tissue from both viremic and virally suppressed people with HIV (PWH) harbored HIV pol DNA in all regions tested, with lower levels present in basal ganglia and cerebellum relative to frontal white matter. Intact proviruses were primarily found in the frontal white matter but also detected in other brain regions of PWH, demonstrating frontal white matter as a major brain reservoir of intact, potentially replication competent HIV DNA that persists despite antiretroviral therapy. ANN NEUROL 2023;94:798-802.

Inducing antiretroviral therapy (ART)-free virological control is a critical step toward a human immunodeficiency virus type 1 (HIV-1) cure. In this phase 2a, placebo-controlled, double-blinded trial, 43 people (85% males) with HIV-1 on ART were randomized to (1) placebo/placebo, (2) lefitolimod (TLR9 agonist)/placebo, (3) placebo/broadly neutralizing anti-HIV-1 antibodies (bNAbs) or (4) lefitolimod/bNAb. ART interruption (ATI) started at week 3. Lefitolimod was administered once weekly for the first 8 weeks, and bNAbs were administered twice, 1 d before and 3 weeks after ATI. The primary endpoint was time to loss of virologic control after ATI. The median delay in time to loss of virologic control compared to the placebo/placebo group was 0.5 weeks (P = 0.49), 12.5 weeks (P = 0.003) and 9.5 weeks (P = 0.004) in the lefitolimod/placebo, placebo/bNAb and lefitolimod/bNAb groups, respectively. Among secondary endpoints, viral doubling time was slower for bNAb groups compared to non-bNAb groups, and the interventions were overall safe. We observed no added benefit of lefitolimod. Despite subtherapeutic plasma bNAb levels, 36% (4/11) in the placebo/bNAb group compared to 0% (0/10) in the placebo/placebo group maintained virologic control after the 25-week ATI. Although immunotherapy with lefitolimod did not lead to ART-free HIV-1 control, bNAbs may be important components in future HIV-1 curative strategies. ClinicalTrials.gov identifier: NCT03837756 .

HIV-1 persists indefinitely in people living with HIV (PLWH) on antiretroviral therapy (ART). If ART is stopped, the virus rapidly rebounds from long-lived latently infected cells. Using a humanized mouse model of HIV-1 infection and CD4+ T cells from PLWH on ART, we investigate whether antagonizing host pro-survival proteins can prime latent cells to die and facilitate HIV-1 clearance. Venetoclax, a pro-apoptotic inhibitor of Bcl-2, depletes total and intact HIV-1 DNA in CD4+ T cells from PLWH ex vivo. This venetoclax-sensitive population is enriched for cells with transcriptionally higher levels of pro-apoptotic BH3-only proteins. Furthermore, venetoclax delays viral rebound in a mouse model of persistent HIV-1 infection, and the combination of venetoclax with the Mcl-1 inhibitor S63845 achieves a longer delay in rebound compared with either intervention alone. Thus, selective inhibition of pro-survival proteins can induce death of HIV-1-infected cells that persist on ART, extending time to viral rebound.

[This corrects the article DOI: 10.20411/pai.v8i2.665.].

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.

In people living with HIV (PLWH) on antiretroviral therapy (ART), virus persists in a latent form where there is minimal transcription or protein expression. Latently infected cells are a major barrier to curing HIV. Increasing HIV transcription and viral production in latently infected cells could facilitate immune recognition and reduce the pool of infected cells that persist on ART. Given that programmed cell death protein 1 (PD-1) expressing CD4+ T cells are preferentially infected with HIV in PLWH on ART, we aimed to determine whether administration of antibodies targeting PD-1 would reverse HIV latency in vivo. We therefore evaluated the impact of intravenous administration of pembrolizumab every 3 weeks on HIV latency in 32 PLWH and cancer on ART. After the first infusion of anti-PD-1, we observed a median 1.32-fold increase in unspliced HIV RNA and 1.61-fold increase in unspliced RNA:DNA ratio in sorted blood CD4+ T cells compared to baseline. We also observed a 1.65-fold increase in plasma HIV RNA. The frequency of CD4+ T cells with inducible virus evaluated using the tat/rev limiting dilution assay was higher after 6 cycles compared to baseline. Phylogenetic analyses of HIV env sequences in a participant who developed low concentrations of HIV viremia after 6 cycles of pembrolizumab did not demonstrate clonal expansion of HIV-infected cells. These data are consistent with anti-PD-1 being able to reverse HIV latency in vivo and support the rationale for combining anti-PD-1 with other interventions to reduce the HIV reservoir.

The main barrier to a cure for HIV is the persistence of long-lived and proliferating latently infected CD4+ T-cells despite antiretroviral therapy (ART). Latency is well characterized in multiple CD4+ T-cell subsets, however, the contribution of regulatory T-cells (Tregs) expressing FoxP3 as well as immune checkpoints (ICs) PD-1 and CTLA-4 as targets for productive and latent HIV infection in people living with HIV on suppressive ART is less well defined. We used multiplex detection of HIV DNA and RNA with immunohistochemistry (mIHC) on formalin-fixed paraffin embedded (FFPE) cells to simultaneously detect HIV RNA and DNA and cellular markers. HIV DNA and RNA were detected by in situ hybridization (ISH) (RNA/DNAscope) and IHC was used to detect cellular markers (CD4, PD-1, FoxP3, and CTLA-4) by incorporating the tyramide system amplification (TSA) system. We evaluated latently infected cell lines, a primary cell model of HIV latency and excisional lymph node (LN) biopsies collected from people living with HIV (PLWH) on and off ART. We clearly detected infected cells that coexpressed HIV RNA and DNA (active replication) and DNA only (latently infected cells) in combination with IHC markers in the in vitro infection model as well as LN tissue from PLWH both on and off ART. Combining ISH targeting HIV RNA and DNA with IHC provides a platform to detect and quantify HIV persistence within cells identified by multiple markers in tissue samples from PLWH on ART or to study HIV latency.

BACKGROUND: Identifying factors that determine the frequency of latently infected CD4+ T cells on antiretroviral therapy (ART) may inform strategies for human immunodeficiency virus (HIV) cure. We investigated the role of CD4+ count at ART initiation for HIV persistence on ART. METHODS: Among participants of the Strategic Timing of Antiretroviral Treatment Study, we enrolled people with HIV (PWH) who initiated ART with CD4+ T-cell counts of 500-599, 600-799, or ≥ 800 cells/mm3. After 36-44 months on ART, the levels of total HIV-DNA, cell-associated unspliced HIV-RNA (CA-US HIV-RNA), and two-long terminal repeat HIV-DNA in CD4+ T cells were quantified and plasma HIV-RNA was measured by single-copy assay. We measured T-cell expression of Human Leucocyte Antigen-DR Isotype (HLA-DR), programmed death-1, and phosphorylated signal transducer and activator of transcription-5 (pSTAT5). Virological and immunological measures were compared across CD4+ strata. RESULTS: We enrolled 146 PWH, 36 in the 500-599, 60 in the 600-799, and 50 in the ≥ 800 CD4 strata. After 36-44 months of ART, total HIV-DNA, plasma HIV-RNA, and HLA-DR expression were significantly lower in PWH with CD4+ T-cell count ≥ 800 cells/mm3 at ART initiation compared with 600-799 or 500-599 cells/mm3. The median level of HIV-DNA after 36-44 months of ART was lower by 75% in participants initiating ART with ≥ 800 vs 500-599 cells/mm3 (median [interquartile range]: 16.3 [7.0-117.6] vs 68.4 [13.7-213.1] copies/million cells, respectively). Higher pSTAT5 expression significantly correlated with lower levels of HIV-DNA and CA-US HIV-RNA. Virological measures were significantly lower in females. CONCLUSIONS: Initiating ART with a CD4+ count ≥ 800 cells/mm3 compared with 600-799 or 500-599 cells/mm3 was associated with achieving a substantially smaller HIV reservoir on ART.

INTRODUCTION: The International AIDS Society convened a multidisciplinary committee of experts in December 2020 to provide guidance and key considerations for the safe and ethical management of clinical trials involving people living with HIV (PLWH) during the SARS-CoV-2 pandemic. This consultation did not discuss guidance for the design of prevention studies for people at risk of HIV acquisition, nor for the programmatic delivery of antiretroviral therapy (ART). DISCUSSION: There is strong ambition to continue with HIV research from both PLWH and the research community despite the ongoing SARS-CoV-2 pandemic. How to do this safely and justly remains a critical debate. The SARS-CoV-2 pandemic continues to be highly dynamic. It is expected that with the emergence of effective SARS-CoV-2 prevention and treatment strategies, the risk to PLWH in clinical trials will decline over time. However, with the emergence of more contagious and potentially pathogenic SARS-CoV-2 variants, the effectiveness of current prevention and treatment strategies may be compromised. Uncertainty exists about how equally SARS-CoV-2 prevention and treatment strategies will be available globally, particularly for marginalized populations, many of whom are at high risk of reduced access to ART and/or HIV disease progression. All of these factors must be taken into account when deciding on the feasibility and safety of developing and implementing HIV research. CONCLUSIONS: It can be assumed for the foreseeable future that SARS-CoV-2 will persist and continue to pose challenges to conducting clinical research in PLWH. Guidelines regarding how best to implement HIV treatment studies will evolve accordingly. The risks and benefits of performing an HIV clinical trial must be carefully evaluated in the local context on an ongoing basis. With this document, we hope to provide a broad guidance that should remain viable and relevant even as the nature of the pandemic continues to develop.

Real-time detection and nanoscale imaging of human immunodeficiency virus type 1 ribonucleic acid (HIV-1 RNA) in latently infected cells that persist in people living with HIV-1 on antiretroviral therapy in blood and tissue may reveal new insights needed to cure HIV-1 infection. Herein, we develop a strategy combining DNA nanotechnology and super-resolution expansion microscopy (ExM) to detect and image a 22 base sequence transcribed from the HIV-1 promoter in model live and fixed cells. We engineer a chimeric locked nucleic acid (LNA)-DNA sensor via hybridization chain reaction to probe HIV-1 RNA in the U3 region of the HIV-1 long terminal repeat (LTR) by signal amplification in live cells. We find that the viral RNA transcript of the U3 region of the HIV-1 LTR, namely PromA, is a valid and specific biomarker to detect infected live cells. The efficiency and selectivity of the LNA-DNA sensor are evaluated in combination with ExM. Unlike standard ExM methods, which rely on additional custom linkers to anchor and immobilize RNA molecules in the intracellular polymeric network, in the current strategy, we probe and image the HIV-1 RNA target at nanoscale resolution, without resorting to chemical linkers or additional preparation steps. This is achieved by physical entrapment of the HIV-1 viral transcripts in the cells post-expansion by finely tuning the mesh size of the intracellular polymeric network.

Programmed cell death 1 (PD1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4) suppress CD4+ T cell activation and may promote latent HIV infection. By performing leukapheresis (n = 21) and lymph node biopsies (n = 8) in people with HIV on antiretroviral therapy (ART) and sorting memory CD4+ T cells into subsets based on PD1/CTLA4 expression, we investigate the role of PD1 and CTLA 4 in HIV persistence. We show that double-positive (PD1+CTLA4+) cells in blood contain more HIV DNA compared with double-negative (PD1-CTLA4-) cells but still have a lower proportion of cells producing multiply spliced HIV RNA after stimulation as well as reduced upregulation of T cell activation and proliferation markers. Transcriptomics analyses identify differential expression of key genes regulating T cell activation and proliferation with MAF, KLRB1, and TIGIT being upregulated in double-positive compared with double-negative cells, whereas FOS is downregulated. We conclude that, in addition to being enriched for HIV DNA, double-positive cells are characterized by negative signaling and a reduced capacity to respond to stimulation, favoring HIV latency.

Latent HIV-1 provirus in infected individuals on suppressive therapy does not always remain transcriptionally silent. Both HIV-1 LTR and human gene promoter derived transcriptional events can contribute HIV-1 sequences to the mRNA produced in the cell. In addition, chimeric cellular:HIV mRNA can arise through readthrough transcription and aberrant splicing. Using target enrichment coupled to the Illumina Mi-Seq and PacBio RS II platforms, we show that 3' LTR activation is frequent in latently infected cells from both the CCL19-induced primary cell model of HIV-1 latency as well as ex vivo samples. In both systems of latent HIV-1 infection, we detected several chimeric species that were generated via activation of a cryptic splice donor site in the 5' LTR of HIV-1. Aberrant splicing involving the major HIV-1 splice donor sites, SD1 and SD4 disrupts post-transcriptional processing of the gene in which HIV-1 is integrated. In the primary cell model of HIV-1 latency, Tat-encoding sequences are incorporated into the chimeric mRNA transcripts through the use of SD4. Our study unravels clues to the characteristics of HIV-1 integrants that promote formation of chimeric cellular:HIV mRNA and improves the understanding of the HIV-1 RNA footprint in latently infected cells.

Antiretroviral therapy (ART) has dramatically improved life expectancy for people with HIV (PWH) and helps to restore immune function but is not curative and must be taken lifelong. Achieving long term control of HIV in the absence of ART will likely require potent T cell function, but chronic HIV infection is associated with immune exhaustion that persists even on ART. This is driven by elevated expression of immune checkpoints that provide negative signalling to T cells. In individuals with cancer, immune checkpoint blockade augments tumour-directed T-cell responses resulting in significant clinical cures. There is therefore high interest if ICB can contribute to HIV cure or remission by reversing HIV-latency and/or drive recovery of HIV-specific T-cells. We here review recent evidence on the role of immune checkpoints in persistent HIV infection and discuss the potential for employing immune checkpoint blockade as a therapeutic approach to target HIV persistence on ART.

A major component of designing drug delivery systems concerns how to amplify or attenuate interactions with specific cell types. For instance, a chemotherapeutic might be functionalized with an antibody to enhance binding to cancer cells ("targeting") or functionalized with polyethylene glycol to help evade immune cell recognition ("stealth"). Even at a cellular level, optimizing the binding and uptake of a drug carrier is a complex biological design problem. Thus, it is valuable to separate how strongly a new carrier interacts with a cell from the functional efficacy of a carrier's cargo once delivered to that cell. To continue the chemotherapeutic example, "how well it binds to a cancer cell" is a separate problem from "how well it kills a cancer cell". Quantitative in vitro assays for the latter are well established and usually rely on measuring viability. However, most published research on cell-carrier interactions is qualitative or semiquantitative. Generally, these measurements rely on fluorescent labeling of the carrier and, consequently, report interactions with cells in relative or arbitrary units. However, this work can be standardized and be made absolutely quantitative with a small number of characterization experiments. Such absolute quantification is valuable, as it facilitates rational, inter- and intra-class comparisons of various drug delivery systems-nanoparticles, microparticles, viruses, antibody-drug conjugates, engineered therapeutic cells, or extracellular vesicles. Furthermore, quantification is a prerequisite for subsequent meta-analyses or in silico modeling approaches. In this article, video guides, as well as a decision tree for how to achieve in vitro quantification for carrier drug delivery systems, are presented, which take into account differences in carrier size and labeling modality. Additionally, further considerations for the quantitative assessment of advanced drug delivery systems are discussed. This is intended to serve as a v

Co-infection with hepatitis B (HBV) and human immunodeficiency virus (HIV) increases overall and liver-related mortality. In order to identify interactions between these two viruses in vivo, full-length HIV proviruses were sequenced from a cohort of HIV-HBV co-infected participants and from a cohort of HIV mono-infected participants recruited from Bangkok, Thailand, both before the initiation of antiretroviral therapy (ART) and after at least 2 years of ART. The co-infected individuals were found to have higher levels of genetically-intact HIV proviruses than did mono-infected individuals pre-therapy. In these co-infected individuals, higher levels of genetically-intact HIV proviruses or proviral genetic-diversity were also associated with higher levels of sCD14 and CXCL10, suggesting that immune activation is linked to more genetically-intact HIV proviruses. Three years of ART decreased the overall level of HIV proviruses, with fewer genetically-intact proviruses being identified in co-infected versus mono-infected individuals. However, ART increased the frequency of certain genetic defects within proviruses and the expansion of identical HIV sequences. IMPORTANCE With the increased availability and efficacy of ART, co-morbidities are now one of the leading causes of death in HIV-positive individuals. One of these co-morbidities is co-infection with HBV. However, co-infections are still relatively understudied, especially in countries where such co-infections are endemic. Furthermore, these countries have different subtypes of HIV circulating than the commonly studied HIV subtype B. We believe that our study serves this understudied niche and provides a novel approach to investigating the impact of HBV co-infection on HIV infection. We examine co-infection at the molecular level in order to investigate indirect associations between the two viruses through their interactions with the immune system. We demonstrate that increased immune inflammation and activation in

The search for clinically effective antivirals against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is ongoing. Repurposing of drugs licensed for non-coronavirus disease 2019 (COVID-19) indications has been extensively investigated in laboratory models and in clinical studies with mixed results. Nafamostat mesylate (nafamostat) is a drug licensed in Japan and Korea for indications including acute pancreatitis and disseminated intravascular coagulation. It is available only for continuous intravenous infusion. In vitro human lung cell line studies with nafamostat demonstrate high antiviral potency against SARS-CoV-2 (half maximal inhibitory concentration [IC50] of 0.0022 µM [compared to remdesivir 1.3 µM]), ostensibly via inhibition of the cellular enzyme transmembrane protease serine 2 (TMPRSS2) preventing viral entry into human cells. In addition, the established antithrombotic activity is hypothesised to be advantageous given thrombosis-associated sequelae of COVID-19. Clinical reports to date are limited, but indicate a potential benefit of nafamostat in patients with moderate to severe COVID-19. In this review, we will explore the pre-clinical, pharmacokinetic and clinical outcome data presently available for nafamostat as a treatment for COVID-19. The recruitment to ongoing clinical trials is a priority to provide more robust data on the safety and efficacy of nafamostat as a treatment for COVID-19.

The most studied HIV eradication approach is the "shock and kill" strategy, which aims to reactivate the latent reservoir by latency reversing agents (LRAs) and allowing elimination of these cells by immune-mediated clearance or viral cytopathic effects. The CNS is an anatomic compartment in which (persistent) HIV plays an important role in HIV-associated neurocognitive disorder. Restriction of the CNS by the blood-brain barrier is important for maintenance of homeostasis of the CNS microenvironment, which includes CNS-specific cell types, expression of transcription factors, and altered immune surveillance. Within the CNS predominantly myeloid cells such as microglia and perivascular macrophages are thought to be a reservoir of persistent HIV infection. Nevertheless, infection of T cells and astrocytes might also impact HIV infection in the CNS. Genetic adaptation to this microenvironment results in genetically distinct, compartmentalized viral populations with differences in transcription profiles. Because of these differences in transcription profiles, LRAs might have different effects within the CNS as compared with the periphery. Moreover, reactivation of HIV in the brain and elimination of cells within the CNS might be complex and could have detrimental consequences. Finally, independent of activity on latent HIV, LRAs themselves can have adverse neurologic effects. We provide an extensive overview of the current knowledge on compartmentalized (persistent) HIV infection in the CNS and on the "shock and kill" strategy. Subsequently, we reflect on the impact and promise of the "shock and kill" strategy on the elimination of persistent HIV in the CNS.

One strategy to eliminate latently infected cells that persist in people with HIV on antiretroviral therapy is to activate virus transcription and virus production to induce virus or immune-mediated cell death. This is called latency reversal. Despite clear activity of multiple latency reversal agents in vitro, clinical trials of latency-reversing agents have not shown significant reduction in latently infected cells. We review new insights into the biology of HIV latency and discuss novel approaches to enhance the efficacy of latency reversal agents.

BACKGROUND: Analytical treatment interruptions (ATI) are pauses of antiretroviral therapy (ART) in the context of human immunodeficiency virus (HIV) cure trials. They are the gold standard in determining if interventions being tested can achieve sustained virological control in the absence of ART. However, withholding ART comes with risks and discomforts to trial participant. We used mathematical models to explore how ATI study design can be improved to maximize statistical power, while minimizing risks to participants. METHODS: Using previously observed dynamics of time to viral rebound (TVR) post-ATI, we modelled estimates for optimal sample size, frequency, and ATI duration required to detect a significant difference in the TVR between control and intervention groups. Groups were compared using a log-rank test, and analytical and stochastic techniques. RESULTS: In placebo-controlled TVR studies, 120 participants are required in each arm to detect 30% difference in frequency of viral reactivation at 80% power. There was little statistical advantage to measuring viral load more frequently than weekly, or interrupting ART beyond 5 weeks in a TVR study. CONCLUSIONS: Current TVR HIV cure studies are underpowered to detect statistically significant changes in frequency of viral reactivation. Alternate study designs can improve the statistical power of ATI trials.

OBJECTIVE: Human immunodeficiency virus (HIV) persistence in blood and tissue reservoirs, including the brain, is a major barrier to HIV cure and possible cause of comorbid disease. However, the size and replication competent nature of the central nervous system (CNS) reservoir is unclear. Here, we used the intact proviral DNA assay (IPDA) to provide the first quantitative assessment of the intact and defective HIV reservoir in the brain of people with HIV (PWH). METHODS: Total, intact, and defective HIV proviruses were measured in autopsy frontal lobe tissue from viremic (n = 18) or virologically suppressed (n = 12) PWH. Total or intact/defective proviruses were measured by detection of HIV pol or the IPDA, respectively, through use of droplet digital polymerase chain reaction (ddPCR). HIV-seronegative individuals were included as controls (n = 6). RESULTS: Total HIV DNA was present at similar levels in brain tissues from untreated viremic and antiretroviral (ART)-suppressed individuals (median = 22.3 vs 26.2 HIV pol copies/106 cells), reflecting a stable CNS reservoir of HIV that persists despite therapy. Furthermore, 8 of 10 viremic and 6 of 9 virally suppressed PWH also harbored intact proviruses in the CNS (4.63 vs 12.7 intact copies/106 cells). Viral reservoirs in CNS and matched lymphoid tissue were similar in the composition of intact and/or defective proviruses, albeit at lower levels in the brain. Importantly, CNS resident CD68+ myeloid cells in virally suppressed individuals harbored HIV DNA, directly showing the presence of a CNS resident HIV reservoir. INTERPRETATION: Our results demonstrate the first evidence for an intact, potentially replication competent HIV reservoir in the CNS of virally suppressed PWH. ANN NEUROL 2022;92:532-544.

Background: Persons living with human immunodeficiency virus (HIV) are at elevated risk of developing the malignant diseases that require allogeneic stem cell transplantation (ASCT). Recent data suggest that these individuals are also at an elevated risk of certain complications post-ASCT. This risk may result from preexisting HIV-related factors affecting dynamics of immune reconstitution post-ASCT. However, to date, there has been little work describing the dynamics of immune reconstitution post-ASCT in persons with HIV and none comparing these data to controls without HIV. Methods: We assessed T-cell reconstitution in 6 ASCT with HIV recipients (HIV+ASCT) compared to a control population of 21 ASCT without HIV recipients. In a subset of HIV+ASCT recipients we performed additional flow cytometry profiling of CD8+ T-cell subsets and antigen specificity of reconstituting CD4+ and CD8+ T cells. Results: We observe no difference in post-ASCT CD4+ T cells between HIV+ASCT and HIV-negative ASCT recipients, despite much lower pre-ASCT CD4+ T-cell counts in the HIV+ASCT group. In contrast, we observed significantly higher CD8+ T-cell numbers in the HIV+ASCT group post-ASCT. The reconstituting CD8+ T-cells were predominantly CD45RO+, whereas homing markers and antigen specificity of these cells varied between participants. Conclusion: This study represents the most extensive characterization of immune-reconstitution post-ASCT in persons with HIV, and the first to our knowledge to compare these data to ASCT controls without HIV. The results indicate that immune reconstitution in this group can be affected by preexisting HIV infection and post-ASCT antigen exposure.

Developing a cure for HIV is a global priority. Target product profiles are a tool commonly used throughout the drug development process to align interested parties around a clear set of goals or requirements for a potential product. Three distinct therapeutic modalities (combination therapies, ex-vivo gene therapy, and in-vivo gene therapy) for a target product profile for an HIV cure were identified. Using a process of expert face-to-face consultation and an online Delphi consultation, we found a high degree of agreement regarding the criteria for the optimum target product profile. Although the minimum attributes for a cure were debated, the broad consensus was that an acceptable cure need not be as safe and effective as optimally delivered antiretroviral therapy. An intervention that successfully cured a reasonable fraction of adults would be sufficient to advance to the clinic. These target product profiles will require further discussion and ongoing revisions as the field matures.

In light of the increasing global burden of new HIV infections, growing financial requirements, and shifting funding landscape, the global health community must accelerate the development and delivery of an HIV cure to complement existing prevention modalities. An effective curative intervention could prevent new infections, overcome the limitations of antiretroviral treatment, combat stigma and discrimination, and provide a sustainable financial solution for pandemic control. We propose steps to plan for an HIV cure now, including defining a target product profile and establishing the HIV Cure Africa Acceleration Partnership (HCAAP), a multidisciplinary public-private partnership that will catalyse and promote HIV cure research through diverse stakeholder engagement. HCAAP will convene stakeholders, including people living with HIV, at an early stage to accelerate the design, social acceptability, and rapid adoption of HIV-cure products.

SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells. Importantly, activated CXCR3+cTFH1 cells in acute COVID-19 significantly correlate with and predict antibody levels and their avidity at convalescence as well as acute neutralization activity. Strikingly, intensive care unit (ICU) patients with severe COVID-19 display higher levels of soluble IL-6, IL-6R, and IL-18, and hyperactivation of innate, adaptive, and myeloid compartments than patients with moderate disease. Our analyses provide a comprehensive map of longitudinal immunological responses in COVID-19 patients and integrate key cellular pathways of complex immune networks underpinning severe COVID-19, providing important insights into potential biomarkers and immunotherapies.

The precise role of CD4 T cell turnover in maintaining HIV persistence during antiretroviral therapy (ART) has not yet been well characterized. In resting CD4 T cell subpopulations from 24 HIV-infected ART-suppressed and 6 HIV-uninfected individuals, we directly measured cellular turnover by heavy water labeling, HIV reservoir size by integrated HIV-DNA (intDNA) and cell-associated HIV-RNA (caRNA), and HIV reservoir clonality by proviral integration site sequencing. Compared to HIV-negatives, ART-suppressed individuals had similar fractional replacement rates in all subpopulations, but lower absolute proliferation rates of all subpopulations other than effector memory (TEM) cells, and lower plasma IL-7 levels (p = 0.0004). Median CD4 T cell half-lives decreased with cell differentiation from naïve to TEM cells (3 years to 3 months, p<0.001). TEM had the fastest replacement rates, were most highly enriched for intDNA and caRNA, and contained the most clonal proviral expansion. Clonal proviruses detected in less mature subpopulations were more expanded in TEM, suggesting that they were maintained through cell differentiation. Earlier ART initiation was associated with lower levels of intDNA, caRNA and fractional replacement rates. In conclusion, circulating integrated HIV proviruses appear to be maintained both by slow turnover of immature CD4 subpopulations, and by clonal expansion as well as cell differentiation into effector cells with faster replacement rates.

The recent dramatic appearance of variants of concern of SARS-coronavirus-2 (SARS-CoV-2) highlights the need for innovative approaches that simultaneously suppress viral replication and circumvent viral escape from host immunity and antiviral therapeutics. Here, we employ genome-wide computational prediction and single-nucleotide resolution screening to reprogram CRISPR-Cas13b against SARS-CoV-2 genomic and subgenomic RNAs. Reprogrammed Cas13b effectors targeting accessible regions of Spike and Nucleocapsid transcripts achieved >98% silencing efficiency in virus-free models. Further, optimized and multiplexed Cas13b CRISPR RNAs (crRNAs) suppress viral replication in mammalian cells infected with replication-competent SARS-CoV-2, including the recently emerging dominant variant of concern B.1.1.7. The comprehensive mutagenesis of guide-target interaction demonstrated that single-nucleotide mismatches does not impair the capacity of a potent single crRNA to simultaneously suppress ancestral and mutated SARS-CoV-2 strains in infected mammalian cells, including the Spike D614G mutant. The specificity, efficiency and rapid deployment properties of reprogrammed Cas13b described here provide a molecular blueprint for antiviral drug development to suppress and prevent a wide range of SARS-CoV-2 mutants, and is readily adaptable to other emerging pathogenic viruses.

BACKGROUND: Serological testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) complements nucleic acid tests for patient diagnosis and enables monitoring of population susceptibility to inform the coronavirus disease 2019 (COVID-19) pandemic response. It is important to understand the reliability of assays with different antigen or antibody targets to detect humoral immunity after SARS-CoV-2 infection and to understand how antibody (Ab) binding assays compare to those detecting neutralizing antibody (nAb), particularly as we move into the era of vaccines. METHODS: We evaluated the performance of 6 commercially available enzyme-linked immunosorbent assays (ELISAs), including a surrogate virus neutralization test (sVNT), for detection of SARS-CoV-2 immunoglobulins (IgA, IgM, IgG), total or nAb. A result subset was compared with a cell culture-based microneutralization (MN) assay. We tested sera from patients with prior reverse transcription polymerase chain reaction-confirmed SARS-CoV-2 infection, prepandemic sera, and potential cross-reactive sera from patients with other non-COVID-19 acute infections. RESULTS: For sera collected >14 days post-symptom onset, the assay achieving the highest sensitivity was the Wantai total Ab at 100% (95% CI, 94.6%-100%), followed by 93.1% for Euroimmun NCP-IgG, 93.1% for GenScript sVNT, 90.3% for Euroimmun S1-IgG, 88.9% for Euroimmun S1-IgA, and 83.3% for Wantai IgM. Specificity for the best-performing assay was 99.5% for the Wantai total Ab, and for the lowest-performing assay it was 97.1% for sVNT (as per the Instructions for Use [IFU]). The Wantai Total Ab had the best agreement with MN at 98% followed by Euroimmun S1-IgA, Euro NCP-IgG, and sVNT (as per IFU) with 97%, 97% and 95%, respectively; Wantai IgM had the poorest agreement at 93%. CONCLUSIONS: Performance characteristics of the SARS-CoV-2 serology assays detecting different antibody types are consistent with those found in previously published reports. E

BACKGROUND: In Australia, COVID-19 diagnosis relies on RT-PCR testing which is relatively costly and time-consuming. To date, few studies have assessed the performance and implementation of rapid antigen-based SARS-CoV-2 testing in a setting with a low prevalence of COVID-19 infections, such as Australia. METHODS: This study recruited participants presenting for COVID-19 testing at three Melbourne metropolitan hospitals during a period of low COVID-19 prevalence. The Abbott PanBioTM COVID-19 Ag point-of-care test was performed alongside RT-PCR. In addition, participants with COVID-19 notified to the Victorian Government were invited to provide additional swabs to aid validation. Implementation challenges were also documented. FINDINGS: The specificity of the Abbott PanBioTM COVID-19 Ag test was 99.96% (95% CI 99.73 - 100%). Sensitivity amongst participants with RT-PCR-confirmed infection was dependent upon the duration of symptoms reported, ranging from 77.3% (duration 1 to 33 days) to 100% in those within seven days of symptom onset. A range of implementation challenges were identified which may inform future COVID-19 testing strategies in a low prevalence setting. INTERPRETATION: Given the high specificity, antigen-based tests may be most useful in rapidly triaging public health and hospital resources while expediting confirmatory RT-PCR testing. Considering the limitations in test sensitivity and the potential for rapid transmission in susceptible populations, particularly in hospital settings, careful consideration is required for implementation of antigen testing in a low prevalence setting. FUNDING: This work was funded by the Victorian Department of Health and Human Services. The funder was not involved in data analysis or manuscript preparation.

BACKGROUND: A research priority in finding a cure for HIV is to establish methods to accurately locate and quantify where and how HIV persists in people living with HIV (PLWH) receiving suppressive antiretroviral therapy (ART). Infusing copper-64 (64Cu) radiolabelled broadly neutralising antibodies targeting HIV envelope (Env) with CT scan and positron emission tomography (PET) identified HIV Env in tissues in SIV infected non-human primates . We aimed to determine if a similar approach was effective in people living with HIV (PLWH). METHODS: Unmodified 3BNC117 was compared with 3BNC117 bound to the chelator MeCOSar and 64Cu (64Cu-3BNC117) in vitro to assess binding and neutralization. In a clinical trial 64Cu-3BNC117 was infused into HIV uninfected (Group 1), HIV infected and viremic (viral load, VL >1000 c/mL; Group 2) and HIV infected aviremic (VL <20 c/mL; Group 3) participants using two dosing strategies: high protein (3mg/kg unlabeled 3BNC117 combined with <5mg 64Cu-3BNC117) and trace (<5mg 64Cu-3BNC117 only). All participants were screened for 3BNC117 sensitivity from virus obtained from viral outgrowth. Magnetic resonance imaging (MRI)/PET and pharmacokinetic assessments (ELISA for serum 3BNC117 concentrations and gamma counting for 64Cu) were performed 1, 24- and 48-hours post dosing. The trial (clincialtrials.gov NCT03063788) primary endpoint was comparison of PET standard uptake values (SUVs) in regions of interest (e.g lymph node groups and gastrointestinal tract). FINDINGS: Comparison of unmodified and modified 3BNC117 in vitro demonstrated no difference in HIV binding or neutralisation. 17 individuals were enrolled of which 12 were dosed including Group 1 (n=4, 2 high protein, 2 trace dose), Group 2 (n=6, 2 high protein, 4 trace) and Group 3 (n=2, trace only). HIV+ participants had a mean CD4 of 574 cells/microL and mean age 43 years. There were no drug related adverse effects and no differences in tissue uptake in regions of interest (e.g lymph node g

HIV-1 Tat protein is essential for virus production. RNA-binding proteins that facilitate Tat production may be absent or downregulated in resting CD4+ T-cells, the main reservoir of latent HIV in people with HIV (PWH) on antiretroviral therapy (ART). In this study, we examined the role of Tat RNA-binding proteins on the expression of Tat and control of latent and productive infection. Affinity purification coupled with mass spectrometry analysis was used to detect binding partners of MS2-tagged tat mRNA in a T cell-line model of HIV latency. The effect of knockdown and overexpression of the proteins of interest on Tat transactivation and translation was assessed by luciferase-based reporter assays and infections with a dual color HIV reporter virus. Out of the 243 interactions identified, knockdown of SRP14 (Signal Recognition Particle 14) negatively affected tat mRNA processing and translation as well as Tat-mediated transactivation, which led to an increase in latent infection. On the other hand, knockdown of HMGB3 (High Mobility Group Box 3) resulted in an increase in Tat transactivation and translation as well as an increase in productive infection. Footprinting experiments revealed that SRP14 and HMGB3 proteins bind to TIM-TAM, a conserved RNA sequence-structure in tat mRNA that functions as a Tat IRES modulator of tat mRNA. Overexpression of SRP14 in resting CD4+ T-cells from patients on ART was sufficient to reverse HIV-1 latency and induce virus production. The role of SRP14 and HMGB3 proteins in controlling HIV Tat expression during latency will be further assessed as potential drug targets.

BACKGROUND: B-cell activating factor (BAFF), an essential cytokine for B lymphocytes activation, has been implicated in the pathogenesis of chronic viral hepatitis. However, the role of BAFF in patients with chronic hepatitis B (CHB) undergoing antiviral therapy is unknown. METHODS: Patients with HBeAg-positive CHB treated with 48-week pegylated interferon (PEG-IFN; n = 42), who had stored plasma samples during treatment were recruited. Serial plasma levels of BAFF and C-X-C motif chemokine 10 (CXCL10) during therapy were measured. RESULTS: Combined response (CR), defined as HBeAg seroconversion with HBV DNA < 2,000 IU/mL plus HBsAg decline ≥ 1 log10 IU/mL at 24 weeks post-treatment, was achieved in 11 (26.2%) patients. BAFF levels were elevated during treatment but decreased to pre-treatment levels after PEG-IFN cessation in both responders and non-responders. Low baseline BAFF (< 770 pg/ml) and high CXCL10 (≥ 320 pg/ml) levels were independently associated with CR in multivariate analysis. Baseline CXCL10/BAFF ratio of ≥ 0.45 was predictive of CR with positive and negative predictive values of 61.5 and 89.7%, respectively. CONCLUSIONS: In summary, low baseline BAFF and high CXCL10 levels were associated with treatment response to PEGIFN. The combined measurement of these immune markers may help individualized decision-making in patients with HBeAg-positive CHB.

BACKGROUND: One strategy being pursued to clear latently infected cells that persist in people living with HIV (PLWH) on antiretroviral therapy (ART) is to activate latent HIV infection with a latency reversing agent (LRA). Surrogate markers that accurately measure virus production following an LRA are needed. METHODS: We quantified cell-associated unspliced (US), multiply spliced (MS) and supernatant (SN) HIV RNA by qPCR from total and resting CD4+ T cells isolated from seven PLWH on ART before and after treatment ex vivo with different LRAs, including histone deacetylase inhibitors (HDACi). MS and plasma HIV RNA were also quantified from PLWH on ART (n-11) who received the HDACi panobinostat. FINDINGS: In total and resting CD4+ T cells from PLWH on ART, detection of US RNA was common while detection of MS RNA was infrequent. Primers used to detect MS RNA, in contrast to US RNA, bound sites of the viral genome that are commonly mutated or deleted in PLWH on ART. Following ex vivo stimulation with LRAs, we identified a strong correlation between the fold change increase in SN and MS RNA, but not the fold change increase in SN and US RNA. In PLWH on ART who received panobinostat, MS RNA was significantly higher in samples with detectable compared to non0detectable plasma HIV RNA. INTERPRETATION: Following administration of an LRA, quantification of MS RNA is more likely to reflect an increase in virion production and is therefore a better indicator of meaningful latency reversal. FUNDING: NHMRC, NIH DARE collaboratory.

T cells play an important role in immunity and repair and are implicated in diseases, including blood cancers, viral infections, and inflammation, making them attractive targets for the treatment and prevention of diseases. Over recent years, the advent of nanomedicine has shown an increase in studies that use nanoparticles as carriers to deliver therapeutic cargo to T cells for ex vivo and in vivo applications. Nanoparticle-based delivery has several advantages, including the ability to load and protect a variety of drugs, control drug release, improve drug pharmacokinetics and biodistribution, and site- or cell-specific targeting. However, the delivery of nanoparticles to T cells remains a major technological challenge, which is primarily due to the nonphagocytic nature of T cells. In this review, we discuss the physiological barriers to effective T cell targeting and describe the different approaches used to deliver cargo-loaded nanoparticles to T cells for the treatment of disease such as T cell lymphoma and human immunodeficiency virus (HIV). In particular, engineering strategies that aim to improve nanoparticle internalization by T cells, including ligand-based targeting, will be highlighted. These nanoparticle engineering approaches are expected to inspire the development of effective nanomaterials that can target or manipulate the function of T cells for the treatment of T cell-related diseases.

Health systems have improved their abilities to identify, diagnose, treat and, increasingly, achieve viral suppression among people living with HIV (PLHIV). Despite these advances, a higher burden of multimorbidity and poorer health-related quality of life are reported by many PLHIV in comparison to people without HIV. Stigma and discrimination further exacerbate these poor outcomes. A global multidisciplinary group of HIV experts developed a consensus statement identifying key issues that health systems must address in order to move beyond the HIV field's longtime emphasis on viral suppression to instead deliver integrated, person-centered healthcare for PLHIV throughout their lives.

COVID-19, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first recognised in late 2019, with over 30 000 000 cases and over 1 000 000 deaths reported by the end of September 2020. SARS-CoV-2 infection is usually associated with fever, cough, coryza, dyspnoea, anosmia, headache and fatigue and may cause pneumonia and hypoxemia. An excessive/dysregulated inflammatory response may lead to lung damage including acute respiratory distress syndrome (ARDS), coagulopathy and other complications. Mortality amongst hospitalised patients is higher in those needing intensive care. In Australia over 27 000 cases with 882 deaths had been reported by 30 September, most in Victoria. Two therapies have proven beneficial in treatment of hospitalised patients in expedited randomised placebo-controlled trials and are now in widespread use. Dexamethasone improved survival of those requiring respiratory support and the antiviral agent remdesivir decreased time to recovery in mild-moderate disease. Remdesivir was authorised by the Australian Therapeutic Goods Administration in July 2020. Over 200 other therapeutics are being tested for COVID-19 in more than 2000 clinical trials, and many more agents are in preclinical development. We review the evidence for some of the candidates for therapy in COVID-19.

BACKGROUND: Circadian transcription factors that regulate cell-autonomous circadian clocks can also increase human immunodeficiency virus (HIV) transcription in vitro. We aimed to determine whether circadian variation in HIV transcription exists in people with HIV (PWH) on antiretroviral therapy (ART). METHODS: We performed a prospective observational study of male PWH on ART, sampling blood every 4 hours for 24 hours. Using quantitative polymerase chain reaction, we quantified expression of circadian-associated genes, HIV deoxyribonucleic acid (DNA), and cell-associated unspliced (CA-US) ribonucleic acid (RNA) in peripheral blood CD4+ T cells. Plasma sex hormones were quantified alongside plasma and salivary cortisol. The primary outcome was to identify temporal variations in CA-US HIV RNA using a linear mixed-effect regression framework and maximum likelihood estimation. RESULTS: Salivary and plasma cortisol, and circadian genes including Clock, Bmal1, and Per3, varied with a circadian rhythm. Cell-associated unspliced HIV RNA and the ratio of CA-US HIV RNA/DNA in CD4+ T cells also demonstrated circadian variations, with no variation in HIV DNA. Circulating estradiol was highly predictive of CA-US HIV RNA variation in vivo. CONCLUSIONS: Cell-associated unspliced HIV RNA in PWH on ART varies temporally with a circadian rhythm. These findings have implications for the design of clinical trials and biomarkers to assess HIV cure interventions.

OBJECTIVES: To describe the first isolation and sequencing of SARS-CoV-2 in Australia and rapid sharing of the isolate. SETTING: SARS-CoV-2 was isolated from a 58-year-old man from Wuhan, China who arrived in Melbourne on 19 January 2020 and was admitted to the Monash Medical Centre, Melbourne from the emergency department on 24 January 2020 with fever, cough, and progressive dyspnoea. MAJOR OUTCOMES: Clinical course and laboratory features of the first reported case of COVID-19 (the illness caused by SARS-CoV-2) in Australia; isolation, whole genome sequencing, imaging, and rapid sharing of virus from the patient. RESULTS: A nasopharyngeal swab and sputum collected when the patient presented to hospital were each positive for SARS-CoV-2 (reverse transcription polymerase chain reaction). Inoculation of Vero/hSLAM cells with material from the nasopharyngeal swab led to the isolation of SARS-CoV-2 virus in culture. Electron microscopy of the supernatant confirmed the presence of virus particles with morphology characteristic of viruses of the family Coronaviridae. Whole genome sequencing of the viral isolate and phylogenetic analysis indicated the isolate exhibited greater than 99.99% sequence identity with other publicly available SARS-CoV-2 genomes. Within 24 hours of isolation, the first Australian SARS-CoV-2 isolate was shared with local and overseas reference laboratories and major North American and European culture collections. CONCLUSIONS: The ability to rapidly identify, propagate, and internationally share our SARS-CoV-2 isolate is an important step in collaborative scientific efforts to deal effectively with this international public health emergency by developing better diagnostic procedures, vaccine candidates, and antiviral agents.

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 ste

OBJECTIVE AND DESIGN: A randomized, open-label pilot study in individuals treated with antiretroviral therapy (ART) since acute HIV infection (AHI) with a regimen including a histone deacetylase inhibitor to induce HIV from latency and control HIV replication during subsequent treatment interruption (TI). METHODS: Fifteen participants who initiated ART at AHI were randomized to vorinostat/hydroxychloroquine/maraviroc (VHM) plus ART (n ​= ​10) or ART alone (n ​= ​5). The VHM arm received three 14-day vorinostat cycles within 10 weeks before TI. ART was resumed for plasma viral load (VL) ​> ​1,000 HIV RNA copies/mL. Primary outcome was proportion of participants on VHM ​+ ​ART versus ART only with VL ​< ​50 copies/mL for 24 weeks after TI. RESULTS: Fifteen participants on ART (median: 178 weeks: range 79-295) enrolled. Two on VHM ​+ ​ART experienced serious adverse events. Fourteen participants underwent TI; all experienced VL rebound with no difference in time between arms: VHM ​+ ​ART (n ​= ​9) median: 4 weeks and ART only (n ​= ​5) median: 5 weeks. VHM induced a 2.2-fold increase in VL (p ​= ​0.008) by single-copy HIV RNA assay after the first cycle. Neopterin levels increased significantly following the first two cycles. After VHM treatment, the frequencies of peripheral blood mononuclear cells harboring total HIV DNA and cell-associated RNA were unchanged. All participants achieved VL suppression following ART re-initiation. CONCLUSIONS: Administration of VHM increased HIV VL in plasma, but this was not sustained. VHM did not impact time to viral rebound following TI and had no impact on the size of the HIV reservoir, suggesting that HIV reservoir elimination will require alternative treatment strategies.

Most people living with HIV (PLHIV) with reliable access to antiretroviral treatment (ART) have a life expectancy similar to uninfected populations. Despite this, HIV can negatively affect their social and psychological wellbeing. This study aimed to enhance understanding of the expectations PLHIV hold for HIV cure research and the implications this has for HIV cure research trials. We interviewed 20 Australian PLHIV about their expectations for HIV cure research outcomes and the impact a potential cure for HIV may have on their everyday lives. Data were analysed thematically, using both inductive and deductive approaches. The significance of a cure for HIV was expressed by participants as something that would offer relief from their sense of vigilance or uncertainty about their health into the future. A cure was also defined in social terms, as alleviation from worry about potential for onward HIV transmission, concerns for friends and family, and the negative impact of HIV-related stigma. Participants did not consider sustained medication-free viral suppression (or remission) as a cure for HIV because this did not offer certainty in remaining virus free in a way that would alleviate these fears and concerns. A cure was seen as complete elimination of HIV from the body. There is an ethical need to consider the expectations of PLHIV in design of, and recruitment for, HIV cure-related research. The language used to describe HIV cure research should differentiate the long-term aspiration of achieving complete elimination of HIV from the body and possible shorter-term therapeutic advances, such as achieving medication free viral suppression.

Tat protein is essential to fully activate HIV transcription and processing of viral mRNA, and therefore determines virus expression in productive replication and the establishment and maintenance of latent infection. Here, we used thermodynamic and structure analyses to define a highly conserved sequence-structure in tat mRNA that functions as Tat IRES modulator of tat mRNA (TIM-TAM). By impeding cap-dependent ribosome progression during authentic spliced tat mRNA translation, TIM-TAM stable structure impacts on timing and level of Tat protein hence controlling HIV production and infectivity along with promoting latency. TIM-TAM also adopts a conformation that mediates Tat internal ribosome entry site (IRES)-dependent translation during the early phases of infection before provirus integration. Our results document the critical role of TIM-TAM in Tat expression to facilitate virus reactivation from latency, with implications for HIV treatment and drug development.