thiourea and HIV-Infections

A focal point in contemporary research aimed at preventing the heterosexual spread of AIDS has been the development of intravaginal anti-HIV microbicides to curb the mucosal human immunodeficiency virus type 1 (HIV-1) transmission.. This article reviews the preclinical activity and safety profile of the thiophene thiourea PETT derivative, HI-443 (N'-[2-(2-thiophene)ethyl]-N'-[2-(5-bromopyridyl)] thiourea]). HI-443 is a rationally designed non-nucleoside reverse transcriptase inhibitor (NNRTI) with unprecedented activity against primary clinical HIV-1 isolates with NRTI or NNRTI resistance, multidrug resistance as well as non-B envelope subtypes of HIV-1. HI-443 exhibited a favorable toxicity and pharmacokinetics profile following oral, intraperitoneal or intravenous administration in rodents and a favorable safety profile after repeated intravaginal dosing via a gel formulation in rabbits and pigs. HI-443 did not induce the secretion of pro-inflammatory cytokines and chemokines by three-dimensional reconstituted human vaginal epithelia integrating Langerhans cells ex vivo or in the in vivo porcine model at therapeutic dose levels. Intravaginally administered HI-443 prevented vaginal transmission of a drug-resistant clinical HIV-1 isolate in the surrogate Hu-PBL-SCID mouse model of AIDS.. The discovery of HI-443 as a non-spermicidal broad-spectrum antiretroviral agent represents a significant step forward in the development of a prophylactic microbicide without contraceptive activity for curbing heterosexual HIV transmission.

Topics: Administration, Intravaginal; Animals; Anti-HIV Agents; Drug Design; Drug Resistance, Multiple, Viral; HIV Infections; HIV-1; Humans; Mice; Pyridines; Rabbits; Reverse Transcriptase Inhibitors; Swine; Thiourea

The most common mode of acquiring HIV-1 is via sexual transmission across the genital mucosa. Topical microbicides are a promising prevention strategy for the protection against HIV infection and may ultimately have an impact on the global AIDS pandemic. The effectiveness of a microbicide to prevent HIV-1 transmission will depend on the evolutionary and genital transmission dynamics of the viral subtypes, and sexual behavioral characteristics. Contemporary antiretroviral therapy has led to virological failure as a result of HIV-1 reverse transcriptase gene mutations. The transmission of these multidrug-resistant HIV-1 variants, and the superinfection with the same or distinct HIV-1 subtypes and recombination is a formidable hindrance inherent to global microbicide development. Consequently, mechanism-based microbicides targeting both the cell-free and cell-associated HIV-1 variants and subtypes can be expected to have superior clinical efficacy and safety profiles compared with polymeric anionic microbicides. This review describes the discovery of potent anti-HIV-1 agents against multidrug-resistant and multitropic HIV-1 variants with implications for global microbicide development. Stampidine and thiourea non-nucleoside reverse transcriptase inhibitors (NNRTIs) have demonstrated highly potent activity against clinically relevant multidrug-resistant and recombinant HIV-1 isolates spanning different subtypes across several continents. Extensive preclinical studies have shown that stampidine and a candidate thiourea NNRTI (HI-443) have clinical potential as a safe combination microbicide to inhibit, prevent or treat mucosal HIV-1 infections.

Topics: Animals; Anti-HIV Agents; Anti-Infective Agents; Dideoxynucleotides; Drug Resistance, Multiple, Viral; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; Pyridines; Stavudine; Thiourea; Thymidine Monophosphate

Thiourea derivatives have been reported to possess many biological activities, among them antiviral and antitumoral properties. As part of our continuing effort to develop new active compounds, we report the synthesis and the evaluation of new fifteen thiourea derivatives with 1,3-benzothiazole-2-yl moiety, among them a group of biologically active (1-7) also underwent cyclization to 1,3-thiazolidin-4-ones. Molecular structure of four compounds (4, 13, 15 and 3a) was determined by an X-ray crystallography. We here report the evaluation of their cytotoxicity against human leukaemia/lymphoma- and solid tumour-derived cell lines and of their antiviral activity against HIV-1 and representatives of ssRNA and dsDNA viruses. Derivative 5 showed an interesting activity against HIV-1 wild type and against variants carrying clinically relevant mutations. A colorimetric enzyme immunoassay clarified its mode of action as a non-nucleoside inhibitor of the reverse transcriptase.

Topics: Anti-HIV Agents; Cell Line, Tumor; Crystallography, X-Ray; Drug Design; HIV Infections; HIV Reverse Transcriptase; HIV-1; Humans; Models, Molecular; Reverse Transcriptase Inhibitors; Structure-Activity Relationship; Thiazolidinediones; Thiourea

Low vitamin D levels in human immunodeficiency virus type-1 (HIV) infected persons are associated with more rapid disease progression and increased risk for Mycobacterium tuberculosis infection. We have previously shown that 1α,25-dihydroxycholecalciferol (1,25D3), the active form of vitamin D, inhibits HIV replication in human macrophages through the induction of autophagy. In this study, we report that physiological concentrations of 1,25D3 induce the production of the human cathelicidin microbial peptide (CAMP) and autophagic flux in HIV and M. tuberculosis co-infected human macrophages which inhibits mycobacterial growth and the replication of HIV. Using RNA interference for Beclin-1 and the autophagy-related 5 homologue, combined with the chemical inhibitors of autophagic flux, bafilomycin A₁, an inhibitor of autophagosome-lysosome fusion and subsequent acidification, and SID 26681509 an inhibitor of the lysosome hydrolase cathepsin L, we show that the 1,25D3-mediated inhibition of HIV replication and mycobacterial growth during single infection or dual infection is dependent not only upon the induction of autophagy, but also through phagosomal maturation. Moreover, through the use of RNA interference for CAMP, we demonstrate that cathelicidin is essential for the 1,25D3 induced autophagic flux and inhibition of HIV replication and mycobacterial growth. The present findings provide a biological explanation for the benefits and importance of vitamin D sufficiency in HIV and M. tuberculosis-infected persons, and provide new insights into novel approaches to prevent and treat HIV infection and related opportunistic infections.

Topics: Antimicrobial Cationic Peptides; Apoptosis Regulatory Proteins; Autophagy; Autophagy-Related Protein 5; Beclin-1; Calcifediol; Cathelicidins; Cells, Cultured; HIV Infections; HIV-1; Humans; Hydrazines; Macrolides; Macrophages; Membrane Proteins; Microtubule-Associated Proteins; Mycobacterium tuberculosis; Phagosomes; RNA Interference; RNA, Small Interfering; Thiourea; Tuberculosis

HIV-1 capsid (CA) and human cyclophilin A (CypA) play important roles in HIV-1 assembly and disassembly processes, which are critical in HIV-1 replication. Based on the discovery of thiourea derivatives targeting both of the two proteins and indicating effective inhibitory activities in our group, we designed and synthesized a new class of thiourea derivatives. Their abilities to bind to capsid and cyclophilin A were determined by ultraviolet spectroscopic analysis, fluorescence binding affinity, and PPIase inhibition assay. Furthermore, the newly synthesized compounds were tested for their antiviral activities and cytotoxicities using CEM cells. According to the biological evaluation and subsequent molecular docking analyses, we studied the structure-activity relationships of thiourea derivatives. Three optimal compounds (K17, K24, K25) based on the achieved structure-activity relationships would be the basis for future optimization.

Topics: Anti-HIV Agents; Capsid; Capsid Proteins; Cell Line; Cell Survival; Cyclophilin A; HIV Infections; HIV-1; Humans; Models, Molecular; Protein Binding; Structure-Activity Relationship; Thiourea

To investigate the in vitro and in vivo mucosal safety of a nonnucleoside reverse transcriptase (RT) inhibitor (PHI-443) and a nucleoside analogue RT inhibitor (stampidine)-based anti-HIV microbicide either alone or in combination.. In vitro and in vivo studies using three-dimensional vaginal epithelia integrating Langerhans cells and 16 New Zealand White rabbits, respectively.. Research laboratory.. Rabbits in groups of four were exposed intravaginally to a gel with and without 1% PHI-443, 1% stampidine, or 1% PHI-443 plus 1% stampidine for 14 days. Cytokine/chemokine release by three-dimensional co-cultures in the presence and absence of PHI-443 or stampidine.. Histologic scoring of vaginal tissue for mucosal toxicity at 24 hours after dosing. Simultaneous evaluation of levels of 10 cytokines (granulocyte-macrophage colony-stimulating factor, interleukin-1 alpha, interleukin-13, macrophage inflammatory protein-1 beta, granulocyte colony-stimulating factor, interleukin-18, tumor necrosis factor-alpha, interleukin-6, interleukin-1 beta, and interferon-gamma) and 6 chemokines (epithelial neutrophil-activating peptide-78, interleukin-8, monocyte/macrophage chemoattractant protein-1, macrophage inflammatory protein-3 alpha, interferon-inducible protein-10, and regulated upon activation of normal T-cell expressed and secreted) in culture media by a multiplexed chemiluminescence-based immunoassay.. In the rabbit model, repeated intravaginal administration of PHI-443 plus stampidine via a gel formulation at concentrations nearly 2,000 and 10,000 times higher than their respective in vitro anti-HIV IC(50) values did not result in vaginal irritation. The levels of proinflammatory cytokines/chemokines secreted by multilayered human genital epithelia integrating Langerhans cells were unaffected by prolonged exposure to PHI-443 or stampidine.. The combination of PHI-443 and stampidine was noncytotoxic to vaginal epithelial cells, nonirritating to vaginal mucosa, and did not induce the secretion of proinflammatory cytokines and chemokines by co-cultures of human genital epithelia and Langerhans cells. These attributes are particularly useful for the clinical development of PHI-443 and stampidine as a combination microbicide and as a prophylactic anti-HIV agent to curb genital transmission of HIV-1 by semen.

Topics: Administration, Intravaginal; Animals; Anti-Infective Agents, Local; Dideoxynucleotides; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Mucous Membrane; Pyridines; Rabbits; Stavudine; Thiourea; Thymidine Monophosphate; Vagina

The in vitro activity profile of N'- [2-(2-thiophene)ethyl]-N'-[2-(5-bromopyridyl)] thiourea (CAS 258340-15-7, HI-443) was examined against 38 clinical isolates of HIV-1. HI-443 inhibited the replication and/or infectivity of each of the 7 HIV-1 isolates of non-B envelope subtype, each of the 22 isolates with genotypic nucleoside reverse transcriptase inhibitor (NRTI) resistance, each of the 6 multidrug-resistant HIV isolates with genotypic NRTI/non-nucleoside reverse transcriptase inhibitor (NNRTI) resistance, each of the 3 isolates with no RT mutations, and each of the 3 laboratory strains of HIV-I with NNRTI or NNRTI/NRTI resistance. The potency of HI-443 against clinical HIV-1 isolates with NRTI- or NNRTI-resistance warrants the further development of this rationally designed NNRTI as a new anti-HIV agent.

Topics: Anti-HIV Agents; Drug Design; Drug Resistance; Drug Resistance, Multiple, Viral; Genotype; HIV Infections; HIV Reverse Transcriptase; HIV-1; Humans; Pyridines; Recombinant Proteins; Reverse Transcriptase Inhibitors; Thiourea; Viral Envelope Proteins; Viral Plaque Assay

The increased risk of heterosexual transmission of human immunodeficiency virus-1 (HIV-1) has prompted the search for safe and effective female-controlled vaginal microbicides. Because endogenous reverse transcription is implicated in augmenting the sexual transmission of HIV-1, potential microbicides should have the inherent ability to optimally inhibit both wild-type and drug-resistant mutant strains of HIV-1. N-[2-(2,5-dimethoxyphenylethyl)]-N'-[2-(5-bromopyridyl)]-thiourea (PHI-236) is a rationally designed non-nucleoside inhibitor of HIV-1 reverse transcriptase (NNRTI) that was deduced from changes in binding pocket size, shape and residue character that result from clinically observed NNRTI resistance mutations. PHI-236 displayed high-binding affinity (Ludi K(i) = 0.07 microM) for HIV-1 RT and robust anti-HIV activity against the wild type (IC50 = <0.001 microM) as well as primary clinical isolates (IC50 = 0.009-0.04 microM) carrying multiple RT gene mutations associated with NRTI and NNRTI resistance. PHI-236 displayed high-selectivity index against human vaginal and cervical epithelial cells and did not affect human sperm functions. In the humanized severe combined immunodeficient mouse model for HIV/acquired immune deficiency syndrome (AIDS), pretreatment of HIV-1 (BaL)-infected human monocytes and semen with PHI-236 prevented the systemic infection via the vaginal route. PHI-236 has particular clinical utility as a non-spermicidal microbicide as well as a prophylactic antiviral agent to inactivate cell-free and cell-associated HIV-1 in semen before assisted reproductive technology procedures.

Topics: Animals; Anti-HIV Agents; Disease Models, Animal; Drug Design; Female; HIV Infections; HIV-1; Humans; Mice; Mice, SCID; Microbial Sensitivity Tests; Premedication; Pyridines; Reverse Transcriptase Inhibitors; Semen; Thiourea

PHI-443 (N'-[2-(2-thiophene)ethyl]-N'-[2-(5-bromopyridyl)] thiourea) is a rationally designed novel thiophene thiourea nonnucleoside reverse transcriptase inhibitor (NNRTI) with potent anti-HIV activity against the wild-type and drug-resistant primary clinical human immunodeficiency virus (HIV-1) isolates. This study examined the potential utility of PHI-443 as a nonspermicidal microbicide for prevention of sexual transmission of HIV. Our goal in this study was to test the effects of PHI-443 on in vivo sperm functions under conditions shown to inactivate viruses in human cells. PHI-443 completely prevented the vaginal transmission of a genotypically and phenotypically drug-resistant HIV-1 isolate in the humanized severe combined immunodeficient (Hu-SCID) mouse model of sexually transmitted AIDS. Exposure of human sperm to PHI-443 at doses 30 000 times higher than those that yield effective concentrations against the AIDS virus had no adverse effect on sperm motility, kinematics, cervical mucus penetrability, or the viability of vaginal and cervical epithelial cells. Exposure of rabbit semen to PHI-443 either ex vivo or in vivo had no adverse impact on in vivo fertilizing ability in the rabbit model. Reproductive indices (i.e., pregnancy rate, embryo implantation, and preimplantation losses) were not affected by pretreatment of rabbit semen with PHI-443. Likewise, intravaginal application of 2% PHI-443 via a self-emulsifying gel at the time of artificial insemination resulted in healthy offspring with no apparent peri- or postnatal repercussions. Repeated intravaginal administration of 0.5%- 2% PHI-443 gel was found to be safe in rabbits and lacked systemic absorption. PHI-443 has clinical potential as a prophylactic broad-spectrum anti-HIV microbicide without contraceptive activity.

Topics: Absorption; Animals; Anti-Infective Agents; Biomechanical Phenomena; Cervix Uteri; Drug Stability; Epithelial Cells; Female; Fertility; Gels; HIV; HIV Infections; Male; Mice; Mice, SCID; Mucus; Proliferating Cell Nuclear Antigen; Pyridines; Rabbits; Semen; Sperm Motility; Spermatozoa; Thiourea; Vagina

HIV-1 infection is associated with serious cardiovascular complications, but the roles of HIV-1, viral proteins, and highly active antiretroviral therapy (HAART) drugs are not understood. HAART decreases the overall risk of heart disease but leads to metabolic disturbances and possibly coronary artery disease. We investigated toxicities of HIV-1, HIV-1 glycoprotein 120 (gp120), and HAART drugs for human coronary artery endothelial cells (CAECs), brain microvascular endothelial cells, and neonatal rat ventricular myocytes (NRVMs). HIV-1 and gp120, but not azidothymidine (AZT), induced apoptosis of NRVMs and CAECs. Ethylisothiourea, an inhibitor of nitric oxide synthase, inhibited apoptosis induction by gp120. AZT, HIV-1, and gp120 all damaged mitochondria of cardiomyocytes. HAART drugs, AZT, and indinavir, but not HIV-1, produced intercellular gaps between confluent endothelial cells and decreased transendothelial electrical resistance. In conclusion, HIV-1 and gp120 induce toxicity through induction of cardiomyocyte and endothelial cell apoptosis. HAART drugs disrupt endothelial cell junctions and mitochondria and could cause vascular damage.

Topics: Animals; Animals, Newborn; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Apoptosis; Cells, Cultured; Coronary Vessels; Dose-Response Relationship, Drug; Drug Combinations; Electric Impedance; Endothelial Cells; Endothelium, Vascular; Gap Junctions; HIV Envelope Protein gp120; HIV Infections; HIV-1; Humans; Indinavir; Mitochondria, Heart; Myocytes, Cardiac; Thiourea; Zidovudine

We have previously demonstrated that tetrahedral bis(cyclopentadienyl)vanadium(IV) complexes and square pyramidal oxovanadium(IV) complexes of vanadium are rapid and selective spermicidal agents at low micromolar concentrations. This study investigated the potential utility of oxovanadium in combination with thiourea non-nucleoside inhibitors (NNIs) of HIV-1 reverse transcriptase (RT) for the development of an effective dual-function anti-HIV spermicide. Two rationally designed substituted phenyl-ring containing pyridyl thiourea NNIs, N-[2-(2-chlorophenethyl)]-N(')-[2-(5-bromopyridyl)-thiourea) [1] and N-[2-(2-methoxyphenethyl)]-N(')-[2-(pyridyl)-thiourea [2] that exhibited subnanomolar IC(50) values against the drug-sensitive, drug-resistant, and multidrug-resistant strains of HIV-1, were complexed with oxovanadium. The oxovanadium-thiourea [OVT] NNIs, C(29)H(27)Br(2)Cl(2)N(6)O(2)S(2)V [3], and C(31)H(35)N(6)O(4)S(2)V [4], were synthesized by reacting VOSO(4), a V(IV) compound, with the corresponding deprotonated thiourea NNI compounds as ligands. Elemental analysis showed that each OVT-NNI used two thiourea molecules as ligands. The existence of the Vz.dbnd6;O bond (968cm(-1)) was confirmed by IR spectroscopy. No d-d bands were observed in the visible spectra of OVT-NNIs and their EPR spectra were featureless, indicating that the vanadium centers were oxidized to V(V). The new OVT-NNIs as well as their thiourea NNI ligands were evaluated for (i) anti-HIV activity using the cell-free recombinant RT inhibition assays, (ii) cellular HIV replication assays, (iii) spermicidal activity against human sperm by computer-assisted sperm analysis (CASA), and (iv) cytotoxicity against normal human female genital tract epithelial cell using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) dye-reduction assays. Similar to thiourea NNIs 1 and 2, the OVT-NNIs 3 and 4, exhibited potent anti-HIV activity with submicromolar IC(50[p24]) values (0.08 and 0.128 microM, respectively) and submicromolar IC(50[RT]) values (2.1 and 0.87 microM, respectively). Notably, OVT-NNIs were spermicidal against human sperm at low micromolar concentrations (IC(50)=34 and 55 microM, respectively) and induced rapid sperm immobilization (T(1/2)=12 and 240s) when compared with their respective thiourea NNI ligands (EC(50)=>400 microM and T(1/2)=>180min). Moreover, OVT-NNIs displayed high selectivity indices against normal female genital tract epithelial cells (IC(50) values >25

Topics: Anti-HIV Agents; Cervix Mucus; Drug Combinations; Female; HIV Infections; HIV Reverse Transcriptase; HIV-1; Humans; Male; Reverse Transcriptase Inhibitors; Sperm Motility; Spermatocidal Agents; Spermatozoa; Thiourea; Vanadium

We assessed the effects of activation with phorbol myrystic acetate (PMA) and ionomycin on peripheral blood mononuclear cells (PBMC) from HIV-infected individuals by (51)Cr release, propidium iodide (PI) uptake, electron microscopy, and DNA analysis. Up to 70% (51)Cr release was induced from PBMC of HIV-infected individuals, versus up to 26% (51)Cr release from PBMC of non-HIV-infected volunteers. Flow cytometry identified mostly T cells undergoing activation-induced cell death (AICD). The kinetics of (51)Cr release and the effects of cold target inhibitors were consistent with cell-mediated cytotoxicity. Certain anti-CD3 antibodies or extracellular Ca(2+) chelation prevented AICD, but antagonistic anti-Fas antibodies, caspase inhibitors, and cycloheximide had no effect. The antioxidants thiourea and N-acetylcysteine reduced AICD, indicating a role for oxidative stress. Electron microscopy revealed plasma membrane disruption with nuclear integrity, while DNA analysis showed intact chromosomal DNA. This form of T cell AICD triggered by PMA and ionomycin differs from classical apoptosis in the absence of either caspase involvement or DNA fragmentation.

Topics: Acetylcysteine; Antioxidants; Caspases; Cell Death; Cells, Cultured; Chromium Radioisotopes; DNA Fragmentation; Fas Ligand Protein; fas Receptor; Flow Cytometry; HIV Infections; Humans; Immunophenotyping; Ionomycin; Lymphocyte Activation; Membrane Glycoproteins; T-Lymphocyte Subsets; T-Lymphocytes; Tetradecanoylphorbol Acetate; Thiourea

A novel computer model of the HIV reverse transcriptase (RT) non-nucleoside inhibitor (NNI) binding pocket, which was generated using high resolution crystal structure information from 9 individual RT/NNI complexes, revealed previously unrecognized ligand derivatization sites for phenethylthiazolylthiourea (PETT) derivatives. Spatial gaps surrounding the pyridyl ring of the active PETT derivative trovirdine were discovered during modeling procedures. Docking studies using the computer-generated model of the binding pocket (composite binding pocket) suggested that the replacement of the planar pyridyl ring of trovirdine with a nonplanar piperidinyl or piperazinyl ring, which occupy larger volumes, would better fill the spacious Wing 2 region of the butterfly-shaped NNI binding pocket. The anti-HIV activity of the synthesized heterocyclic compounds N-[2-(1-piperidinylethyl)]-N'-[2-(5-bromopyridyl)]-thiourea and N-[2-(1-piperazinylethyl)]-N'-[2-(5-bromopyridyl)]-thiourea was examined in HTLVIIIB-infected peripheral blood mononuclear cells. Both compounds were more potent than trovirdine and abrogated HIV replication at nanomolar concentrations without any evidence of cytotoxicity.

Topics: Antiviral Agents; Binding Sites; Computer Simulation; Drug Design; HIV Core Protein p24; HIV Infections; HIV Reverse Transcriptase; HIV-1; Humans; Leukocytes, Mononuclear; Models, Molecular; Piperazines; Reverse Transcriptase Inhibitors; Structure-Activity Relationship; Thiourea; Virus Replication