Inhibition Of HIV-1 Replication Research Articles

Hide and seek: for HIV-infected CD4+ T cells, playing well comes with maturity.

Antiretroviral therapy suppresses HIV replication but leaves a population of infected CD4+ T cells with integrated proviruses. While most of these proviruses contain defects, such as deletions, some intact proviruses persist and can reinitiate viral replication. In this issue of the JCI, Duette, Hiener, and colleagues performed a tour de force proviral landscape analysis on clinical samples collected over many years with in vitro functional assays. The researchers showed that effector memory CD4+ T cells provide partial sanctuary to intact proviruses from CD8+ T cells and this was associated with superior Nef-mediated MHC-I downregulation relative to less mature CD4+ T cell populations. This finding implicates differential immunoevasion as a cell-intrinsic property, influencing proviral persistence, and highlights Nef as a therapeutic target.

Biallelic, Selectable, Knock-in Targeting of CCR5 via CRISPR-Cas9 Mediated Homology Directed Repair Inhibits HIV-1 Replication.

Transplanting HIV-1 positive patients with hematopoietic stem cells homozygous for a 32 bp deletion in the chemokine receptor type 5 (CCR5) gene resulted in a loss of detectable HIV-1, suggesting genetically disrupting CCR5 is a promising approach for HIV-1 cure. Targeting the CCR5-locus with CRISPR-Cas9 was shown to decrease the amount of CCR5 expression and HIV-1 susceptibility in vitro as well as in vivo. Still, only the individuals homozygous for the CCR5-Δ32 frameshift mutation confer complete resistance to HIV-1 infection. In this study we introduce a mechanism to target CCR5 and efficiently select for cells with biallelic frameshift insertion, using CRISPR-Cas9 mediated homology directed repair (HDR). We hypothesized that cells harboring two different selectable markers (double positive), each in one allele of the CCR5 locus, would carry a frameshift mutation in both alleles, lack CCR5 expression and resist HIV-1 infection. Inducing double-stranded breaks (DSB) via CRISPR-Cas9 leads to HDR and integration of a donor plasmid. Double-positive cells were selected via fluorescence-activated cell sorting (FACS), and CCR5 was analyzed genetically, phenotypically, and functionally. Targeted and selected populations showed a very high frequency of mutations and a drastic reduction in CCR5 surface expression. Most importantly, double-positive cells displayed potent inhibition to HIV-1 infection. Taken together, we show that targeting cells via CRISPR-Cas9 mediated HDR enables efficient selection of mutant cells that are deficient for CCR5 and highly resistant to HIV-1 infection.

The Prevalence of HIV-infected Patients with Virological Suppression but a CD4+ T-cell Count of ≤ 200 Cells/mm3 after Highly Active Antiretroviral Therapy Initiation: A Meta-analysis.

Highly active antiretroviral therapy (HAART) strongly inhibits HIV replication. However, many patients show suboptimal immune recovery (SIR), as defined by virological suppression (i.e. low viral load) with a CD4+ T-cell count of ≤ 200 cells/mm3, after HAART initiation. Here, we performed a systematic evaluation of the SIR prevalence among HIV-infected patients in cohort studies. We searched PubMed, Cochrane Library, Embase, CNKI, Wanfang database, and Chinese Biomedicine Database for cohort studies about HIV-infected participants whose CD4+ T-cell count was ≤ 200 cells/mm3 but still had virological suppression after HAART initiation. The SIR prevalence from each of those cohort studies was pooled into a random-effect meta-analysis. We obtained two kinds of pooled post-HARRT initiation SIR prevalence: one among participants with virological suppression (11 cohort studies involving 18,672 participants), and the other among all HIV-infected participants (seven cohort studies involving 12,063 participants). The pooled SIR prevalence among HIV-infected patients with virological suppression after HAART initiation was 43% (95% confidence interval [CI], 34-51%) at 6 months post-HAART initiation and 10% (95% CI, 5-18%) at 36 months post-HAART initiation; among all HIV-infected patients after HAART initiation, it was 17% (95% CI, 0-55%) and 5% (95% CI, 2-10%) at 6 and 36 months post-HAART initiation, respectively. The SIR prevalence among HIV-infected patients is high at 6 months post-HAART initiation, but its prevalence gradually reduces over time under continuous HAART. Thus, it is important to follow-up on variations in the CD4+ T-cell count and viral load.

Design, Synthesis, and Preclinical Profiling of GSK3739936 (BMS-986180), an Allosteric Inhibitor of HIV-1 Integrase with Broad-Spectrum Activity toward 124/125 Polymorphs.

Allosteric HIV-1 integrase inhibitors (ALLINIs) have garnered special interest because of their novel mechanism of action: they inhibit HIV-1 replication by promoting aberrant integrase multimerization, leading to the production of replication-deficient viral particles. The binding site of ALLINIs is in a well-defined pocket formed at the interface of two integrase monomers that is characterized by conserved residues along with two polymorphic amino acids at residues 124 and 125. The design, synthesis, and optimization of pyridine-based allosteric integrase inhibitors are reported here. Optimization was conducted with a specific emphasis on the inhibition of the 124/125 polymorphs such that the designed compounds showed excellent potency in vitro against majority of the 124/125 variants. In vivo profiling of promising preclinical lead 29 showed that it exhibited a good pharmacokinetic (PK) profile in preclinical species, which resulted in a low predicted human efficacious dose. However, findings in rat toxicology studies precluded further development of 29.

Low-level Viremia in Treated HIV-1 Infected Patients: Advances and Challenges

Antiretroviral therapy (ART) can effectively suppress HIV-1 replication, improving quality of life and restoring the lifespan of persons living with HIV (PLWH) to near-normal levels. However, after standardized ART, a low level of HIV-1 RNA, i.e., low-level viremia (LLV), may still be identified in 3% to 10% of the patients. LLV is capable of impacting the immunological and clinical outcomes of patients and serves as a risk factor for transmission. The underlying mechanism of LLV is not yet certain, and the effects of LLV on patient outcomes remain under evaluation. Understanding LLV will allow effective prevention and control strategies to be designed for the benefit of PLWH.

Short Communication: S100A8 and S100A9, Biomarkers of SARS-CoV-2 Infection and Other Diseases, Suppress HIV Replication in Primary Macrophages.

S100A8 and S100A9 are members of the Alarmin family; these proteins are abundantly expressed in neutrophils, form a heterodimer complex, and are secreted in plasma on pathogen infection or acute inflammatory diseases. Recently, both proteins were identified as novel biomarkers of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and were shown to play key roles in inducing an aggressive inflammatory response by mediating the release of large amounts of pro-inflammatory cytokines, called the "cytokine storm." Although co-infection with SARS-CoV-2 in people living with HIV-1 may result in an immunocompromised status, the role of the S100A8/A9 complex in HIV-1 replication in primary T cells and macrophages is still unclear. Here, we evaluated the roles of the proteins in HIV replication to elucidate their functions. We found that the complex had no impact on virus replication in both cell types; however, the subunits of S100A8 and S100A9 inhibit HIV in macrophages. These findings provide important insights into the regulation of HIV viral loads during SARS-CoV-2 co-infection.

Abstract P4-04-04: APOBEC3F is expressed by immune cells and is associated with immune response and survival in triple negative breast cancer

Abstract Background: The Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like (APOBEC) cytidine deaminases subfamily has been a focus of attention as a cause of characteristic somatic mutations in breast cancer. APOBEC3A and APOBEC3B are known to be the key mutation drivers in breast cancer, while the other APOBEC3 family members have been implicated in infection. APOBEC3F was reported to inhibit HIV replication, but its role in cancer has not been reported. We hypothesized that APOBEC3F is associated with infiltrating immune cells and immune responses in tumor microenvironment, and with survival of breast cancer patients. Method: We analyzed a total of 2978 breast cancer patients’ clinical data and transcriptome from the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and The Cancer Genome Atlas (TCGA) datasets. We also used a total of 21802 single-cell transcriptomes from the GSE75688 and GSE114725 single-cell sequencing datasets of the primary breast cancer cohort. We defined "high expression" as top two thirds of APOBEC3F expression in each cohort. Result: APOBEC3F expression was significantly high in triple negative (TNBC), which is known to have the most abundant immune cell infiltration among the subtypes. Disease-specific survival (DSS) and overall survival (OS) were consistently better in high APOBEC3F TNBC (all p < 0.05), but not in luminal subtype, that led us to hypothesize that APOBEC3F may enhance cancer immunity. APOBEC3F expression was not consistently associated with intratumor heterogeneity, mutation rates nor neoantigens that are all reflections of cancer cells in both TNBC and luminal breast cancer, except for HRD in TNBC (p = 0.024). APOBEC3F expression did not correlate with response to any of the drugs tested in breast cancer cell lines in vitro. On the other hand, APOBEC3F expression was consistently associated with multiple types of immune cell infiltrations, such as CD8+ T-cells, M1 and M2 macrophage, Dendritic cells, Natural Killer cells (NK), and B-cells (all p < 0.05) with high CYT (p < 0.001) regardless of subtype. In TNBC, high APOBEC3F tumor significantly enriched only immune-related gene sets; inflammatory response, IL-2/STAT5 signaling, IFN γ response, IFN α response,IL-6/JAC/STAT3 signaling and complement, consistently in both cohorts, and associated with high levels of immune activity scores such as IFN-γ response, tumor infiltrating lymphocytes regional fraction, lymphocyte infiltration signature, leukocyte fraction, and TCR richness in TCGA cohort (all p < 0.05). In luminal breast cancer, high APOBEC3F tumor significantly enriched not only immune-related gene sets similar to TNBC, but also tumor aggravating gene sets such as KRAS signaling, PI3K signaling, angiogenesis, metabolism-related gene sets, as well as apoptosis-related gene sets. We further found that APOBEC3F was exclusively expressed in immune cells compared to myeloid, stromal, and cancer cells using the GSE75688 breast cancer single cell sequencing cohort, and highly expressed in CD8, CD4, NK, and B-cells, and neutrophils in GSE114725 breast cancer single cell sequencing cohort (both p < 0.001). High APOBEC3F immune cells were significantly associated with higher expression of IFN-γ, cytolytic activity score and its component genes, and with immune cell proliferation (all p < 0.001). High APOBEC3F tumor was associated with significantly elevated levels of all the immune checkpoint molecules tested (all p < 0.001). Conclusion: Our study demonstrated that high APOBEC3F gene expression is exclusively expressed in immune cells and is associated with immune response, immune cytolytic activity in the tumor microenvironment, and with favorable survival in triple-negative breast cancer using in silico bioinformatic analyses of multiple independent large patient cohorts. Citation Format: Rongrong Wu, Masanori Oshi, Mariko Asaoka, Akimitsu Yamada, Li Yan, Itaru Endo, Takashi Ishikawa, Kazuaki Takabe. APOBEC3F is expressed by immune cells and is associated with immune response and survival in triple negative breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P4-04-04.

Piroxicam Analogs: Design, Synthesis, Docking Study and Biological Evaluation as Promising Anti-HIV-1 Agents.

In this study, we describe the synthesis, docking study and biological evaluation of 1,2-benzothiazines 1,1-dioxide derivatives. Taking the well-known drug, Piroxicam as a lead compound, we designed and synthesized two series of 1,2-benzothiazines 1,1-dioxide derivatives to assay their ability in inhibition of HIV-1 replication in cell culture. Most of the new compounds were active in the cell-based anti-HIV-1 assay with EC50 < 50 μM. Among them, compound 7g was found to be the most active molecule.Docking study using 3OYA pdb code on the most active molecule 7g with EC50 values of 10 μM showed a similar binding mode to the HIV integrase inhibitors. Since all the compounds showed no remarkable cytotoxicity (CC50> 500 μM), the designed scaffold is promising structure for the development of new anti-HIV-1 agents.

Red-sea dolomite as a sustainable catalyst in the synthesis of bis-indolyl methanes with molecular docking validation as HIV-1 replication inhibitor

ABSTRACT. Dolomite minerals were collected from the Red Sea Mountains around the Sokhna region. The rock was collected, rinsed, and crushed using a ball mailing machine and used without further purification. The dolomite sample was characterized using FTIR, XRD, SEM/EDAX, and mapping to ensure their composition and homogeneity. The obtained data reveal that the presence of a homogenous crystalline structure of CaMg(CO3)2. The characterized rock was used as a catalyst in the eco-friendly synthesis of bis-indolyl methane derivatives by reacting two moles of unsubstituted indole and various aromatic aldehydes in the presence of Red-Sea Dolomite mineral as an economical, recyclable, easily obtained, and nontoxic catalyst under solvent-free conditions. The molecular docking study explained that the bis-indolyl methane can be considered as a small molecule stimulator of HIV-1 frameshifting and inhibitor of viral replication.&#x0D; &#x0D; KEY WORDS: Indole, Dolomite, HIV-1, Catalyst, Frameshifting, Viral replication&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2021, 35(3), 647-657.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v35i3.15

Updates on CRISPR-based gene editing in HIV-1/AIDS therapy.

Although tremendous efforts have been made to prevent and treat HIV-1 infection, HIV-1/AIDS remains a major threat to global human health. The combination antiretroviral therapy (cART), although able to suppress HIV-1 replication, cannot eliminate the proviral DNA integrated into the human genome and thus requires lifelong treatment that may lead to various side effects. In recent years, clustered regularly interspaced short palindromic repeat (CRISPR)-associated nuclease 9 (Cas9) related gene-editing systems have been developed and designed as effective ways to treat HIV-1 infection. However, new gene-targeting tools derived from or functioning like CRISPR/Cas9, including base editor, prime editing, SHERLOCK, DETECTR, PAC-MAN, ABACAS, pfAGO, have been developed and optimized for pathogens detection and diseases correction. Here, we summarize recent studies on HIV-1/AIDS gene therapy and provide more gene-editing targets based on studies relating to the molecular mechanism of HIV-1 infection. We also identify the strategies and potential applications of these new gene-editing technologies for HIV-1/AIDS treatment in the future. Moreover, we discuss the caveats and problems that should be addressed before the clinical use of these versatile CRISPR-based gene targeting tools. Finally, we offer alternative solutions to improve the practice of gene targeting in HIV-1/AIDS gene therapy.

The Activated Macrophage - A Tough Fortress for Virus Invasion: How Viruses Strike Back.

Macrophages (Mφ) are innate immune cells with a variety of functional phenotypes depending on the cytokine microenvironment they reside in. Mφ exhibit distinct activation patterns that are found within a wide array of activation states ranging from the originally discovered classical pro-inflammatory (M1) to the anti-inflammatory (M2) with their multi-facades. M1 cells are induced by IFNγ + LPS, while M2 are further subdivided into M2a (IL-4), M2b (Immune Complex) and M2c (IL-10) based on their inducing stimuli. Not surprisingly, Mφ activation influences the outcome of viral infections as they produce cytokines that in turn activate cells of the adaptive immune system. Generally, activated M1 cells tend to restrict viral replication, however, influenza and HIV exploit inflammation to support their replication. Moreover, M2a polarization inhibits HIV replication at the post-integration level, while HCMV encoded hrIL-10 suppresses inflammatory reactions by facilitating M2c formation. Additionally, viruses such as LCMV and Lassa Virus directly suppress Mφ activation leading to viral chronicity. Here we review how Mφ activation affects viral infection and the strategies by which viruses manipulate Mφ polarization to benefit their own fitness. An understanding of these mechanisms is important for the development of novel immunotherapies that can sway Mφ phenotype to inhibit viral replication.

Synthesis and anti-HIV activity of a new isoxazole containing disubstituted 1,2,4-oxadiazoles analogs

Continuing on our antiviral drug discovery research, we intended to diversify our lead anti-HIV-1 inhibitor by non-classical isosteric replacement of amide to 1,2,4-oxadiazoles. The resulting molecules isoxazole-1,2,4-oxadiazole analogs were synthesized using mild bases in ethanol under microwave irradiation. The anti-HIV potential was checked in human CD4+ reporter cell lines, TZM-bl and CEM-GFP, at the highest non-cytotoxic concentration (HNC), demonstrating that 3-((3-(p-tolyl)isoxazol-5-yl)methyl)-1,2,4-oxadiazole and 3-((3-(4-chlorophenyl)isoxazol-5-yl)methyl)-1,2,4-oxadiazole inhibit HIV-1 replication significantly and could be considered as a new lead candidate against HIV-1.

Selection and identification of an RNA aptamer that specifically binds the HIV-1 capsid lattice and inhibits viral replication.

The HIV-1 capsid core participates in several replication processes. The mature capsid core is a lattice composed of capsid (CA) monomers thought to assemble first into CA dimers, then into ∼250 CA hexamers and 12 CA pentamers. CA assembly requires conformational flexibility of each unit, resulting in the presence of unique, solvent-accessible surfaces. Significant advances have improved our understanding of the roles of the capsid core in replication; however, the contributions of individual CA assembly forms remain unclear and there are limited tools available to evaluate these forms in vivo. Here, we have selected aptamers that bind CA lattice tubes. We describe aptamer CA15-2, which selectively binds CA lattice, but not CA monomer or CA hexamer, suggesting that it targets an interface present and accessible only on CA lattice. CA15-2 does not compete with PF74 for binding, indicating that it likely binds a non-overlapping site. Furthermore, CA15-2 inhibits HIV-1 replication when expressed in virus producer cells, but not target cells, suggesting that it binds a biologically-relevant site during virus production that is either not accessible during post-entry replication steps or is accessible but unaltered by aptamer binding. Importantly, CA15-2 represents the first aptamer that specifically recognizes the HIV-1 CA lattice.

Cannabinoid receptor type 2 agonist JWH-133 decreases cathepsin B secretion and neurotoxicity from HIV-infected macrophages

HIV-associated neurocognitive disorders (HAND) are prevalent despite combined antiretroviral therapy (cART), affecting 52% of people living with HIV. Our laboratory has demonstrated increased expression of cathepsin B (CATB) in postmortem brain tissue with HAND. Increased secretion of CATB from in vitro HIV-infected monocyte-derived macrophages (MDM) induces neurotoxicity. Activation of cannabinoid receptor type 2 (CB2R) inhibits HIV-1 replication in macrophages and the neurotoxicity induced by viral proteins. However, it is unknown if CB2R agonists affect CATB secretion and neurotoxicity in HIV-infected MDM. We hypothesized that HIV-infected MDM exposed to CB2R agonists decrease CATB secretion and neurotoxicity. Primary MDM were inoculated with HIV-1ADA and treated with selective CB2R agonists JWH-133 and HU-308. HIV-1 p24 and CATB levels were determined from supernatants using ELISA. MDM were pre-treated with a selective CB2R antagonist SR144528 before JWH-133 treatment to determine if CB2R activation is responsible for the effects. Neuronal apoptosis was assessed using a TUNEL assay. Results show that both agonists reduce HIV-1 replication and CATB secretion from MDM in a time and dose-dependent manner and that CB2R activation is responsible for these effects. Finally, JWH-133 decreased HIV/MDM-CATB induced neuronal apoptosis. Our results suggest that agonists of CB2R represent a potential therapeutic strategy against HIV/MDM-induced neurotoxicity.

Inhibitors of HIV-1 Nef-Mediated Activation of the Myeloid Src-Family Kinase Hck Block HIV-1 Replication in Macrophages and Disrupt MHC-I Downregulation.

HIV-1 Nef is an attractive target for antiretroviral drug discovery because of its role in promoting HIV-1 infectivity, replication, and host immune system avoidance. Here, we applied a screening strategy in which recombinant HIV-1 Nef protein was coupled to activation of the Src-family tyrosine kinase Hck, which enhances the HIV-1 life cycle in macrophages. Nef stimulates recombinant Hck activity in vitro, providing a robust assay for chemical library screening. High-throughput screening of more than 730 000 compounds using the Nef·Hck assay identified six unique hit compounds that bound directly to recombinant Nef by surface plasmon resonance (SPR) in vitro and inhibited HIV-1 replication in primary macrophages in the 0.04 to 5 μM range without cytotoxicity. Eighty-four analogs were synthesized around an isothiazolone scaffold from this series, many of which bound to recombinant Nef and inhibited HIV-1 infectivity in the low to submicromolar range. Compounds in this series restored MHC-I to the surface of HIV-infected primary cells and disrupted a recombinant protein complex of Nef with the C-terminal tail of MHC-I and the μ1 subunit of the AP-1 endocytic trafficking protein. Nef inhibitors in this class have the potential to block HIV-1 replication in myeloid cells and trigger recognition of HIV-infected cells by the adaptive immune system in vivo.

A Conserved uORF Regulates APOBEC3G Translation and Is Targeted by HIV-1 Vif Protein to Repress the Antiviral Factor.

The HIV-1 Vif protein is essential for viral fitness and pathogenicity. Vif decreases expression of cellular restriction factors APOBEC3G (A3G), A3F, A3D and A3H, which inhibit HIV-1 replication by inducing hypermutation during reverse transcription. Vif counteracts A3G at several levels (transcription, translation, and protein degradation) that altogether reduce the levels of A3G in cells and prevent its incorporation into viral particles. How Vif affects A3G translation remains unclear. Here, we uncovered the importance of a short conserved uORF (upstream ORF) located within two critical stem-loop structures of the 5′ untranslated region (5′-UTR) of A3G mRNA for this process. A3G translation occurs through a combination of leaky scanning and translation re-initiation and the presence of an intact uORF decreases the extent of global A3G translation under normal conditions. Interestingly, the uORF is also absolutely required for Vif-mediated translation inhibition and redirection of A3G mRNA into stress granules. Overall, we discovered that A3G translation is regulated by a small uORF conserved in the human population and that Vif uses this specific feature to repress its translation.

Decreased MIP-3α Production from Antigen-Activated PBMCs in Symptomatic HIV-Infected Subjects.

CD4+ CCR6+ T cells are highly susceptible to HIV infection, and a high cytokine producing CCR6+ T cell subset is selectively lost during HIV infection. The CCR6 chemokine MIP-3α (CCL20) is produced at sites of infection in SIV animal models. Recently, we have shown that MIP-3α inhibits HIV replication. This inhibition of HIV infection is mediated by CCR6 signaling and eventuates in increased APOBEC3G expression. Since there are few existing reports on the role of MIP-3α in health or disease, we studied its production by PBMCs from HIV-seronegative and HIV+ subjects. We evaluated the ability of PBMCs to produce MIP-3α in response to antigen stimulation using cells obtained from two groups: one composed of HIV-seronegative subjects (n = 16) and the other composed of HIV+ subjects (n = 58), some asymptomatic and some with clinically defined AIDS. Antigens included fragment C of the tetanus toxin, Candida albicans, whole-inactivated HIV, and HIV p24. MIP-3α was detected by ELISA in tissue culture supernatants of antigen-stimulated PBMCs. MIP-3α production by antigen-stimulated PBMCs was readily measured for HIV-negative subjects and for HIV-seropositive asymptomatic subjects, but not for patients with AIDS. These results suggest that subversion of the MIP-3α-CCR6 axis by HIV during the course of infection contributes to the loss of immune function that eventually leads to AIDS.

IL-27 induces IFN/STAT1-dependent genes and enhances function of TIGIT+ HIVGag-specific T cells

SummaryHIV-specific T cells have diminished effector function and fail to control/eliminate the virus. IL-27, a member of the IL-6/IL-12 cytokine superfamily has been shown to inhibit HIV replication. However, whether or not IL-27 can enhance HIV-specific T cell function is largely unknown. In the present manuscript, we investigated the role of IL-27 signaling in human T cells by evaluating the global transcriptional changes related to the function of HIV-specific T cells. We found that T cells from people living with HIV (PLWH), expressed higher levels of STAT1 leading to enhanced STAT1 activation upon IL-27 stimulation. Observed IL-27 induced transcriptional changes were associated with IFN/STAT1-dependent pathways in CD4 and CD8 T cells. Importantly, IL-27 dependent modulation of T-bet expression promoted IFNγ secretion by TIGIT+HIVGag-specific T cells. This new immunomodulatory effect of IL-27 on HIV-specific T cell function suggests its potential therapeutic use in cure strategies.

Discovery, optimization, and target identification of novel coumarin derivatives as HIV-1 reverse transcriptase-associated ribonuclease H inhibitors

Despite significant advances in antiretroviral therapy, acquired immunodeficiency syndrome remains as one of the leading causes of death worldwide. New antiretroviral drugs combined with updated treatment strategies are needed to improve convenience, tolerability, safety, and antiviral efficacy of available therapies. In this work, a focused library of coumarin derivatives was exploited by cell phenotypic screening to discover novel inhibitors of HIV-1 replication. Five compounds (DW-3, DW-4, DW-11, DW-25 and DW-31) showed moderate activity against wild-type and drug-resistant strains of HIV-1 (IIIB and RES056). Four of those molecules were identified as inhibitors of the viral RT-associated RNase H. Structural modification of the most potent DW-3 and DW-4 led to the discovery of compound 8a. This molecule showed increased potency against wild-type HIV-1 strain (EC50=3.94±0.22μM) and retained activity against a panel of mutant strains, showing EC50 values ranging from 5.62μM to 202μM. In enzymatic assays, 8a was found to inhibit the viral RNase H with an IC50 of 12.3μM. Molecular docking studies revealed that 8a could adopt a binding mode similar to that previously reported for other active site HIV-1 RNase H inhibitors.

HIV and AIDS

In the quarter-century since the first report of AIDS in the United States, HIV infection has spread throughout the population, disproportionately affecting black women, Hispanic women, and men who have sex with men. The prognosis for persons infected with HIV has improved dramatically with the introduction and evolution of highly active antiretroviral therapy (HAART). The underlying principle of HAART is that a combination of potent antiretrovirals, each of which requires different mutations in the HIV genome for resistance to develop, can suppress replication sufficiently to prevent mutation and the emergence of resistance. The prospect that currently available antiretroviral therapy (ART) regimens may suppress HIV replication indefinitely provides the hope that infected patients will have life expectancies similar to those of age-matched uninfected individuals. For these patients, HIV care has shifted from an emphasis on treatment and prevention of the complications of HIV disease itself to a focus on suppression of HIV replication and management of short- and long-term complications of HIV, ART toxicities, and aging. This chapter describes the epidemiology, pathophysiology and pathogenesis, prevention, diagnosis, and management of acute and chronic HIV infection and AIDS, with figures and tables illustrating each chapter section. This review contains 9 highly rendered figures, 22 tables, and 248 references.