Human Immunodeficiency Virus Gene Research Articles

Mitotic deacetylase complex (MiDAC) recognizes the HIV-1 core promoter to control activated viral gene expression.

The human immunodeficiency virus (HIV) integrates into the host genome forming latent cellular reservoirs that are an obstacle for cure or remission strategies. Viral transcription is the first step in the control of latency and depends upon the hijacking of the host cell RNA polymerase II (Pol II) machinery by the 5' HIV LTR. Consequently, "block and lock" or "shock and kill" strategies for an HIV cure depend upon a full understanding of HIV transcriptional control. The HIV trans-activating protein, Tat, controls HIV latency as part of a positive feed-forward loop that strongly activates HIV transcription. The recognition of the TATA box and adjacent sequences of HIV essential for Tat trans-activation (TASHET) of the core promoter by host cell pre-initiation complexes of HIV (PICH) has been shown to be necessary for Tat trans-activation, yet the protein composition of PICH has remained obscure. Here, DNA-affinity chromatography was employed to identify the mitotic deacetylase complex (MiDAC) as selectively recognizing TASHET. Using biophysical techniques, we show that the MiDAC subunit DNTTIP1 binds directly to TASHET, in part via its CTGC DNA motifs. Using co-immunoprecipitation assays, we show that DNTTIP1 interacts with MiDAC subunits MIDEAS and HDAC1/2. The Tat-interacting protein, NAT10, is also present in HIV-bound MiDAC. Gene silencing revealed a functional role for DNTTIP1, MIDEAS, and NAT10 in HIV expression in cellulo. Furthermore, point mutations in TASHET that prevent DNTTIP1 binding block the reactivation of HIV by latency reversing agents (LRA) that act via the P-TEFb/7SK axis. Our data reveal a key role for MiDAC subunits DNTTIP1, MIDEAS, as well as NAT10, in Tat-activated HIV transcription and latency. DNTTIP1, MIDEAS and NAT10 emerge as cell cycle-regulated host cell transcription factors that can control activated HIV gene expression, and as new drug targets for HIV cure strategies.

Multiple treatment interruptions and protecting HIV-specific CD4 T cells enable durable CD8 T cell response and viral control.

Human Immunodeficiency Virus (HIV) remains a global health challenge, and novel approaches to improve HIV control are significantly important. The cell and gene therapy product AGT103-T was previously evaluated (NCT04561258) for safety, immunogenicity, and persistence in seven patients for up to 180 days post infusion. In this study, we sought to investigate the impact of AGT103-T treatment upon analytical treatment interruptions (ATIs). Six patients previously infused with AGT103-T were enrolled into an ATI study (NCT05540964), wherein they suspended their antiretroviral therapy (ART) until their viral load reached 100,000 copies/mL in two successive visits, or their CD4 count was reduced to below 300 cells/μL. During the ATI, all patients experienced viral rebound followed by a notable expansion in HIV specific immune responses. The participants demonstrated up to a five-fold increase in total CD8 counts over baseline approximately 1-2 weeks followed by the peak viremia. This coincided with a rise in HIV-specific CD8 T cells, which was attributed to the increase in antigen availability and memory recall. Thus, the protocol was amended to include a second ATI with the first ATI serving as an "auto-vaccination." Four patients participated in a second ATI. During the second ATI, the Gag-specific CD8 T cells were either maintained or rose in response to viral rebound and the peak viremia was substantially decreased. The patients reached a viral set point ranging from 7,000 copies/mL to 25,000 copies/mL. Upon resuming ART, all participants achieved viral control more rapidly than during the first ATI, with CD4 counts remaining within 10% of baseline measurements and without any serious adverse events or evidence of drug resistance. In summary, the rise in CD8 counts and the viral suppression observed in 100% of the study participants are novel observations demonstrating that AGT103-T gene therapy when combined with multiple ATIs, is a safe and effective approach for achieving viral control, with viral setpoints consistently below 25,000 copies/mL and relatively stable CD4 T cell counts. We conclude that HIV cure-oriented cell and gene therapy trials should include ATI and may benefit from designs that include multiple ATIs when induction of CD8 T cells is required to establish viral control.

Direct and indirect effects of CYTOR lncRNA regulate HIV gene expression.

The implementation of antiretroviral therapy (ART) has effectively restricted the transmission of Human Immunodeficiency Virus (HIV) and improved overall clinical outcomes. However, a complete cure for HIV remains out of reach, as the virus persists in a stable pool of infected cell reservoir that is resistant to therapy and thus a main barrier towards complete elimination of viral infection. While the mechanisms by which host proteins govern viral gene expression and latency are well-studied, the emerging regulatory functions of non-coding RNAs (ncRNA) in the context of T cell activation, HIV gene expression and viral latency have not yet been thoroughly explored. Here, we report the identification of the Cytoskeleton Regulator (CYTOR) long non-coding RNA (lncRNA) as an activator of HIV gene expression that is upregulated following T cell stimulation. Functional studies show that CYTOR suppresses viral latency by directly binding to the HIV promoter and associating with the cellular positive transcription elongation factor (P-TEFb) to activate viral gene expression. CYTOR also plays a global role in regulating cellular gene expression, including those involved in controlling actin dynamics. Depletion of CYTOR expression reduces cytoplasmic actin polymerization in response to T cell activation. In addition, treating HIV-infected cells with pharmacological inhibitors of actin polymerization reduces HIV gene expression. We conclude that both direct and indirect effects of CYTOR regulate HIV gene expression.

Advances in HIV Gene Therapy.

Early gene therapy studies held great promise for the cure of heritable diseases, but the occurrence of various genotoxic events led to a pause in clinical trials and a more guarded approach to progress. Recent advances in genetic engineering technologies have reignited interest, leading to the approval of the first gene therapy product targeting genetic mutations in 2017. Gene therapy (GT) can be delivered either in vivo or ex vivo. An ex vivo approach to gene therapy is advantageous, as it allows for the characterization of the gene-modified cells and the selection of desired properties before patient administration. Autologous cells can also be used during this process which eliminates the possibility of immune rejection. This review highlights the various stages of ex vivo gene therapy, current research developments that have increased the efficiency and safety of this process, and a comprehensive summary of Human Immunodeficiency Virus (HIV) gene therapy studies, the majority of which have employed the ex vivo approach.

HIV-1 proviral DNA in purified peripheral blood CD34+ stem and progenitor cells in individuals with long-term HAART; paving the way to HIV gene therapy

Human immunodeficiency virus (HIV)-1 infection is an important public health problem worldwide. After primary HIV-1 infection, transcribed HIV-1 DNA is integrated into the host genome, serving as a reservoir of the virus and hindering a definite cure. Although highly active antiretroviral therapy suppresses active viral replication, resulting in undetectable levels of HIV RNA in the blood, a viral rebound can be detected after a few weeks of treatment interruption. This supports the concept that there is a stable HIV-1 reservoir in people living with HIV-1. Recently, a few individuals with HIV infection were reported to be probably cured by hematopoietic stem transplantation (HSCT). The underlying mechanism for this success involved transfusion of uninfected hematopoietic stem and progenitor cells (HSPCs) from CCR5-mutated donors who were naturally resistant to HIV infection. Thus, gene editing technology to provide HIV-resistant HSPC has promise in the treatment of HIV infections by HSCT. In this study, we aimed to find HIV-infected individuals likely to achieve a definite cure via gene editing HSCT. We screened for total HIV proviral DNA by Alu PCR in peripheral blood mononuclear cells (PBMCs) of 20 HIV-infected individuals with prolonged viral suppression. We assessed the amount of intact proviral DNA via a modified intact proviral DNA assay (IPDA) in purified peripheral CD34+ HSPCs. PBMCs from all 20 individuals were positive for the gag gene in Alu PCR, and peripheral CD34+ HSPCs were IPDA-negative for six individuals. Our results suggested that these six HIV-infected individuals could be candidates for further studies into the ability of gene editing HSCT to lead to a definite HIV cure.

A new look at the immunopathogenesis of infection caused by the human immunodeficiency virus

Thanks to the achievements of biotechnology and genetics, numerous features of reproduction of the human immunodeficiency virus and its immunopathogenesis have been established. Genetic studies have called into question the African origin of the virus. Thus, the number of individuals with mutational changes in the CCR5∆32 allele among the population providing genetic protection against human immunodeficiency virus is decreasing from north to south. The probability of adaptation of the great ape virus in the human population is characterized. New biological effects and their influence on the immunopathogenesis of infection of the well-known human immunodeficiency virus genes Gag (structural proteins), Pol (enzymes) and Env (envelope glycoproteins), the proteins encoded by them, as well as a number of additional proteins have been discovered. Thus, the main task of the Tat gene is to stimulate the transcription of proviral deoxyribonucleic acid and the transport of ribonucleic acid from the nucleus to the cytoplasm of the cell. Rev promotes the synthesis of viral structural proteins and enzymes, ensures the availability of full-sized genomic ribonucleic acid for inclusion in the reproduced viral progeny. Viruses with the absence of the vif gene are about 1000 times less virulent compared to wild strains. The APOBEC3G factor inhibits the reproduction of lentiviruses in primates, but in humans it is characterized by polymorphism of biological effects. Viral protein R affects the rate of reproduction of the virus in T-lymphocytes, contributes to their destruction. It also promotes proteasomal degradation and protein modification. Vpr targets may be a structurally specific endonuclease subunit SLX4, uracil-deoxynucleoacid glycosylase 2, and a helicase-like transcription factor. Vpu is a powerful inhibitor of teterin by type 1 immunodeficiency viruses of group M, and in group N viruses it shows low activity. Vpu, Nef, and Env proteins of most lentiviruses are characterized by higher tropicity to the CD4 receptor compared to teterin, serine incorporation proteins. These proteins are incorporated into viral particles and reduce their infectivity by inhibiting fusion with target cells. The protein containing the tripartite motif 5a, the protein of mixovirus activity 2/B constitute an ancient system of protection against retroviruses and are extremely variable in their effectiveness to disrupt the reproduction of viruses.

Role of long noncoding RNA in regulating HIV infection-a comprehensive review.

A complete cure against human immunodeficiency virus (HIV) infection remains out of reach, as the virus persists in stable cell reservoirs that are resistant to antiretroviral therapy. The key to eliminating these reservoirs lies in deciphering the processes that govern viral gene expression and latency. However, while we comprehensively understand how host proteins influence HIV gene expression and viral latency, the emerging role of long noncoding RNAs (lncRNAs) in the context of T cell activation, HIV gene expression, and viral latency remain unexplored. This review dives into the evolving significance of lncRNAs and their impact on HIV gene expression and viral latency. We provide an overview of the current knowledge regarding how lncRNAs regulate HIV gene expression, categorizing them as either activators or inhibitors of viral gene expression and infectivity. Furthermore, we offer insights into the potential therapeutic applications of lncRNAs in combatting HIV. A deeper understanding of how lncRNAs modulate HIV gene transcription holds promise for developing novel RNA-based therapies to complement existing treatment strategies to eradicate HIV reservoirs.

CRISPR gene technology—the next best thing in medicine

CRISPR gene technology—the next best thing in medicine

Synthetic gRNA/Cas9 Ribonucleoprotein Inhibits HIV Reactivation and Replication.

The current antiretroviral therapy (ART) for human immunodeficiency virus (HIV) can halt viral replication but cannot eradicate HIV infection because proviral DNA integrated into the host genome remains genetically silent in reservoir cells and is replication-competent upon interruption or cessation of ART. CRISPR/Cas9-based technology is widely used to edit target genes via mutagenesis (i.e., nucleotide insertion/deletion and/or substitution) and thus can inactivate integrated proviral DNA. However, CRISPR/Cas9 delivery systems often require viral vectors, which pose safety concerns for therapeutic applications in humans. In this study, we used synthetic guide RNA (gRNA)/Cas9-ribonucleoprotein (RNP) as a non-viral formulation to develop a novel HIV gene therapy. We designed a series of gRNAs targeting different HIV genes crucial for HIV replication and tested their antiviral efficacy and cellular cytotoxicity in lymphoid and monocytic latent HIV cell lines. Compared with the scramble gRNA control, HIV-gRNA/Cas9 RNP-treated cells exhibited efficient viral suppression with no apparent cytotoxicity, as evidenced by the significant inhibition of latent HIV DNA reactivation and RNA replication. Moreover, HIV-gRNA/Cas9 RNP inhibited p24 antigen expression, suppressed infectious viral particle production, and generated specific DNA cleavages in the targeted HIV genes that are confirmed by DNA sequencing. Because of its rapid DNA cleavage, low off-target effects, low risk of insertional mutagenesis, easy production, and readiness for use in clinical application, this study provides a proof-of-concept that synthetic gRNA/Cas9 RNP drugs can be utilized as a novel therapeutic approach for HIV eradication.

The Results of Clinical Trials of Recombinant Vaccine Virus, MVA Strain, Expressing Genes of Human Immunodeficiency Virus

Although successes in antiretroviral therapy (ART) turned AIDS from lethal illness into sluggishly progressing disease, its prevention and treatment remain one of the most socially significant concerns. The increase in the number of patients infected with human immunodeficiency virus (HIV), especially in the USA, South America and Europe, determines the need in creating a vaccine against this disease. Existing vaccination practice has demonstrated efficiency of priming/boosting scheme for the development of immune responses. As anti-vector immunity of priming vector can constrain the response to boosting immunization with the same vaccine, heterologous priming/boosting vector constructs are used. An ideal AIDS vaccine would prevent virus dissemination and control viral replication, but it also must be safe for HIV-infected contingent. The vaccination of HIV-infected individuals is used for enhancing immune-mediated elimination of persistently HIV-infected CD4+ Т-cells during long-term ART in order to purge the latently infected viral reservoirs. The paper considers the results of clinical trials of DNA-anti-HIV/AIDS vaccines and recombinant MVA strain of vaccinia virus, expressing different combination of HIV genes, which demonstrated the safety and tolerability both, in HIV-infected and non-HIV-infected volunteers. All implemented schedules of vaccination induced cell-mediated and humoral immune responses in all volunteers. And though there are no data on acquiring AIDS by HIV-uninfected volunteers from groups at low risk of HIV-infection, there are no grounds to conclude the sufficiency of induced protection for the prevention of possible HIV infection.

Stem Cell Therapy and Its Significance in HIV Infection.

Human immunodeficiency virus (HIV) infection is a major global public health issue. Despite this, the only treatment available in mainstay is antiretroviral therapy. This treatment is not curative, it needs to be used lifelong, and there are many issues with compliance and side effects. In recent years, stem cell therapy has shown promising results in HIV management, and it can have a major impact on the future of HIV treatment and prevention. The idea behind anti-HIV hematopoietic stem/progenitor cell (HSPC)-directed gene therapy is to genetically engineer patient-derived (autologous) HSPC to acquire an inherent resistance to HIV infection. Multiple stem-cell-based gene therapy strategies have been suggested that may infer HIV resistance including anti-HIV gene reagents and gene combinatorial strategies giving rise to anti-HIV gene-modified HSPCs. Such stem cells can hamper HIV progression in the body by interrupting key stages of HIV proliferation: viral entry, viral integration, HIV gene expression, etc.Hematopoietic stem cells (HSCs) may also protect leukocytes from being infected. Additionally, genetically engineered HSCs have the ability to continuously produce protected immune cells by prolonged self-renewal that can attack the HIV virus. Therefore, a successful treatment strategy has the potential to control the infection at a steady state and eradicate HIV from patients. This will allow for a potential future benefit with stem cell therapy in HIV treatment.

Genome-wide CRISPR knockout screen identifies ZNF304 as a silencer of HIV transcription that promotes viral latency.

Despite the widespread use of anti-retroviral therapy, human immunodeficiency virus (HIV) still persists in an infected cell reservoir that harbors transcriptionally silent yet replication-competent proviruses. While significant progress has been made in understanding how the HIV reservoir is established, transcription repression mechanisms that are enforced on the integrated viral promoter have not been fully revealed. In this study, we performed a whole-genome CRISPR knockout screen in HIV infected T cells to identify host genes that potentially promote HIV latency. Of several top candidates, the KRAB-containing zinc finger protein, ZNF304, was identified as the top hit. ZNF304 silences HIV gene transcription through associating with TRIM28 and recruiting to the viral promoter heterochromatin-inducing methyltransferases, including the polycomb repression complex (PRC) and SETB1. Depletion of ZNF304 expression reduced levels of H3K9me3, H3K27me3 and H2AK119ub repressive histone marks on the HIV promoter as well as SETB1 and TRIM28, ultimately enhancing HIV gene transcription. Significantly, ZNF304 also promoted HIV latency, as its depletion delayed the entry of HIV infected cells into latency. In primary CD4+ cells, ectopic expression of ZNF304 silenced viral transcription. We conclude that by associating with TRIM28 and recruiting host transcriptional repressive complexes, SETB1 and PRC, to the HIV promoter, ZNF304 silences HIV gene transcription and promotes viral latency.

Analysis of the Interaction Between HIV and Periodontopathic Bacteria That Reactivates HIV Replication in Latently Infected Cells.

The acquired immunodeficiency syndrome (AIDS) pandemic caused by the human immunodeficiency virus (HIV) is a major global health concern affecting 38 million people worldwide. HIV gene expression is the major determinant of the rate of viral replication leading to the progression of AIDS. The persistence of cellular reservoirs of HIV proviruses, despite prolonged treatment with antiretroviral drugs, represents the main obstacle preventing the eradication of HIV. Epigenetic silencing by histone deacetylase (HDAC) contributes to maintaining HIV transcriptional latency. However, the mechanism of the switch from latency to full HIV replication is unknown. HIV infection and antiretroviral treatment or a combination of both contribute to a higher incidence and severity of periodontitis. Periodontopathic bacteria such as Porphyromonas gingivalis and Fusobacterium nucleatum produce high concentrations of butyric acid, which strongly inhibit HDAC, indicating that periodontitis may mediate the reactivation of HIV replication. Here we describe a stepwise protocol for analyzing HIV reactivation by periodontal pathogens. However, the experiments using HIV requires BSL3 containment, making it difficult to handle HIV in dentistry. Therefore, we present an experimental method using cell lines latently infected with HIV.

Acetylation of Cytidine Residues Boosts HIV-1 Gene Expression by Increasing Viral RNA Stability

Epitranscriptomic RNA modifications, including methylation of adenine and cytidine residues, are now recognized as key regulators of both cellular and viral mRNA function. Moreover, acetylation of the N4 position of cytidine (ac4C) was recently reported to increase the translation and stability of cellular mRNAs. Here, we show that ac4C and N-acetyltransferase 10 (NAT10), the enzyme that adds ac4C to RNAs, have been subverted by human immunodeficiency virus 1 (HIV-1) to increase viral gene expression. HIV-1 transcripts are modified with ac4C at multiple discrete sites, and silent mutagenesis of these ac4C sites led to decreased HIV-1 gene expression. Similarly, loss of ac4C from viral transcripts due to depletion of NAT10 inhibited HIV-1 replication by reducing viral RNA stability. Interestingly, the NAT10 inhibitor remodelin could inhibit HIV-1 replication at concentrations that have no effect on cell viability, thus identifying ac4C addition as a potential target for antiviral drug development.

Functional DNA Structures and Their Biomedical Applications

Since the discovery of the double-helix structure in 1953, nucleic acids have been developed from natural genetic codes into functional building blocks in a wide range of biotechnology and material...

A visual detection of human immunodeficiency virus gene using ratiometric method enabled by phenol red and target-induced catalytic hairpin assembly

Relying on the specific coordination of Ag+ and mismatched cytosine-cytosine (C–C), the high-efficiency inhibition of urease by Ag+ ion, and the rapid and sensitive response of phenol red to pH, a sensitive ratiometric sensor has been designed for visual detection of human immunodeficiency virus gene (HIV DNA). This sensor utilizes the HIV DNA to initiate catalytic hairpin assembly (CHA) process, releasing Ag+ to inhibit subsequent urease-catalyzed urea hydrolysis and prevent the pH of the solution from rising. The CHA process and the absorbance ratio of phenol red at different wavelengths (A559/A432) amplify the signal, allowing the sensor to detect HIV DNA from 10 to 130 nM in a sensitive and highly selective manner with a low detection limit of 7.8 nM. In addition, this sensor can visually distinguish different concentrations of HIV DNA within a certain range and possesses a good recovery in 1% of serum samples, which will provide new ideas for biosensor design, dipstick test, blood test, and other clinical disease prevention.

Acetylation of Cytidine Residues Boosts HIV-1 Gene Expression by Increasing Viral RNA Stability

Epitranscriptomic RNA modifications, including methylation of A and C residues, are now recognized as key regulators of both cellular and viral mRNA function. Moreover, acetylation of the N4 position of cytidine (ac4C) was recently reported to increase the translation and stability of cellular mRNAs. Here, we show that ac4C and N-acetyltransferase 10 (NAT10), the enzyme that adds ac4C to RNAs, have been subverted by human immunodeficiency virus 1 (HIV-1) to increase viral gene expression. HIV-1 transcripts are modified with ac4C at multiple discreet sites, and silent mutagenesis of these ac4C sites led to decreased HIV-1 gene expression. Similarly, loss of ac4C from viral transcripts due to depletion of NAT10 inhibited HIV-1 replication by reducing viral RNA stability. Interestingly, the NAT10 inhibitor Remodelin could inhibit HIV-1 replication at levels that have no effect on cell viability, thus identifying ac4C addition as a potential novel target for antiviral drug development.

Fused in sarcoma silences HIV gene transcription and maintains viral latency through suppressing AFF4 gene activation

BackgroundThe human immunodeficiency virus (HIV) cell reservoir is currently a main obstacle towards complete eradication of the virus. This infected pool is refractory to anti-viral therapy and harbors integrated proviruses that are transcriptionally repressed but replication competent. As transcription silencing is key for establishing the HIV reservoir, significant efforts have been made to understand the mechanism that regulate HIV gene transcription, and the role of the elongation machinery in promoting this step. However, while the role of the super elongation complex (SEC) in enhancing transcription activation of HIV is well established, the function of SEC in modulating viral latency is less defined and its cell partners are yet to be identified.ResultsIn this study we identify fused in sarcoma (FUS) as a partner of AFF4 in cells. FUS inhibits the activation of HIV transcription by AFF4 and ELL2, and silences overall HIV gene transcription. Concordantly, depletion of FUS elevates the occupancy of AFF4 and Cdk9 on the viral promoter and activates HIV gene transcription. Live cell imaging demonstrates that FUS co-localizes with AFF4 within nuclear punctuated condensates, which are disrupted upon treating cells with aliphatic alcohol. In HIV infected cells, knockout of FUS delays the gradual entry of HIV into latency, and similarly promotes viral activation in a T cell latency model that is treated with JQ1. Finally, effects of FUS on HIV gene transcription are also exhibited genome wide, where FUS mainly occupies gene promoters at transcription starting sites, while its knockdown leads to an increase in AFF4 and Cdk9 occupancy on gene promoters of FUS affected genes.ConclusionsTowards eliminating the HIV infected reservoir, understanding the mechanisms by which the virus persists in the face of therapy is important. Our observations show that FUS regulates both HIV and global gene transcription and modulates viral latency, thus can potentially serve as a target for future therapy that sets to reactivate HIV from its latent state.

Sociodemographic and Clinical Variables Associated with the Risk of Buruli Ulcer Acquisition: A Systematic Review and Meta-Analysis

Background: Buruli ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans, with poorly understood acquisition risk factors. This review aims at evaluating the importance of sociodemographic - sex, age and family ties with history of BU - and clinical - Bacillus Calmette-Guerin (BCG) immunization, Human Immunodeficiency Virus (HIV) infection and gene variants - in this process. Methods: A systematic review was performed considering the following databases: ClinicalTrials.gov, Cochrane Controlled Register of Trials (CENTRAL), Current Contents Connect, Embase, MEDLINE, SciELO, Scopus and Web of Science. Eligible studies were critically appraised with The Joanna Briggs Institute checklists and heterogeneity was assessed with Cochran Q-test and I2 statistic. Published demographic data was descriptively analysed and clinical data pooled within random-effects modelling for meta-analysis. Findings: A total of 29 studies were included in the systematic review and two randomised controlled trials (RCTs) and 20 case-control studies were selected for meta-analysis. Studies show BU mainly affects age extremes, more preponderately males among children. Data pooled from RCTs do not reveal BCG to be protective against BU (odds ratio (OR) = 0·63; 95% CI = 0·38-1·05; I2 = 56%), a finding later case-control studies appear to corroborate. HIV infection (OR = 6·40; 95% CI = 2·12-19·29; I2 = 0%) and SLC11A1 rs17235409 A allele (OR = 1·86; 95% CI = 1·25-2·77;I2= 0%) are associated with increased prevalence of the disease. No definite conclusions can be drawn regarding the influence of previous family history of BU. Interpretation: These findings have direct implications on current interventions and future research programs, opening avenues on fundamental research topics and fostering the development of more cost-effective preventive and screening measures. Funding Statement: This work was developed under the scope of the project NORTE-01-0145-FEDE13, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (FEDER); FEDER, through the Competitiveness Factors Operational Programme (COMPETE) and by National funds, through the Foundation for Science and Technology (FCT), under the scope of project POCI-01-0145-FEDER-007038 and POCI-01-0145-FEDER-031312; Infect-ERA grant Infect-ERA/0002/2015; and FCT, through the PhD grant PD/BD/113699/2015 to JF, fellowship UMINHO/BI/427/2018 to NS, and postdoctoral grant SFRH/BPD/112903/2015 to AGF. Declaration of Interests: Authors state that they have no conflict of interest to declare. Ethics Approval Statement: The study was registered at PROSPERO with number CRD42019123611.

Identification of 5-Substituted 2-Acylaminothiazoles That Activate Tat-Mediated Transcription in HIV-1 Latency Models.

The persistent reservoir of cells latently infected with human immunodeficiency virus (HIV)-integrated proviral DNA necessitates lifelong suppressive antiretroviral therapy (ART). Epigenetic targeted compounds have shown promise as potential latency-reversing agents; however, these drugs have undesirable toxicity and lack specificity for HIV. We utilized a novel HEK293-derived FlpIn dual-reporter cell line, which quantifies specific HIV provirus reactivation (LTR promoter) relative to nonspecific host cell gene expression (CMV promoter), to identify the 5-substituted 2-acylaminothiazole hit class. Here, we describe the optimization of the hit class, defining the functionality necessary for HIV gene activation and for improving in vitro metabolism and solubility. The optimized compounds displayed enhanced HIV gene expression in HEK293 and Jurkat 10.6 latency cellular models and increased unspliced HIV RNA in resting CD4+ T cells isolated from HIV-infected individuals on ART, demonstrating the potential of the 2-acylaminothiazole class as latency-reversing agents.