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Sample records for amastigotes enhance hiv-1

  1. Citron kinase enhances ubiquitination of HIV-1 Gag protein and intracellular HIV-1 budding.

    PubMed

    Ding, Jiwei; Zhao, Jianyuan; Sun, Lei; Mi, Zeyun; Cen, Shan

    2016-09-01

    Assembly and budding of human immunodeficiency virus type 1 (HIV-1) particles is a complex process involving a number of host proteins. We have previously reported that the RhoA effector citron kinase enhances HIV-1 production. However, the underlying mechanism is not clear. In this study, we found that citron kinase interacted with HIV-1 Gag protein via its zinc finger and leucine zipper domains. Electron microscopy analysis revealed that citron kinase induced viral particle assembly in multivesicular bodies (MVBs). Citron kinase enhanced ubiquitination of HIV-1 Gag protein. Knockdown of Nedd4L, a member of the HECT ubiquitin E3 ligase family, partly decreased the ability of citron kinase to enhance HIV-1 production and reduced ubiquitination of HIV-1 Gag. Interestingly, the function of citron kinase to promote HIV-1 budding was severely impaired when endogenous ALIX was knocked down. Overexpression of the AAA-type ATPase VPS4 eliminated citron-kinase-mediated enhancement of HIV-1 production. Our results suggest that citron kinase interacts with HIV-1 Gag and enhances HIV-1 production by promoting Gag ubiquitination and inducing viral release via the MVB pathway. PMID:27339686

  2. Cyclophilin B enhances HIV-1 infection.

    PubMed

    DeBoer, Jason; Madson, Christian J; Belshan, Michael

    2016-02-01

    Cyclophilin B (CypB) is a member of the immunophilin family and intracellular chaperone. It predominantly localizes to the ER, but also contains a nuclear localization signal and is secreted from cells. CypB has been shown to interact with the Gag protein of human immunodeficiency type 1 (HIV-1). Several proteomic and genetic studies identified it as a potential factor involved in HIV replication. Herein, we show that over-expression of CypB enhances HIV infection by increasing nuclear import of viral DNA. This enhancement was unaffected by cyclosporine treatment and requires the N-terminus of the protein. The N-terminus contains an ER leader sequence, putative nuclear localization signal, and is required for secretion. Deletion of the N-terminus resulted in mislocalization from the ER and suppression of HIV infection. Passive transfer experiments showed that secreted CypB did not impact HIV infection. Combined, these experiments show that intracellular CypB modulates a pathway of HIV nuclear import. PMID:26774171

  3. Histone acetyltransferases regulate HIV-1 enhancer activity in vitro

    PubMed Central

    Sheridan, Philip L.; Mayall, Timothy P.; Verdin, Eric; Jones, Katherine A.

    1997-01-01

    Specific inhibitors of histone deacetylase, such as trichostatin A (TSA) and trapoxin (TPX), are potent inducers of HIV-1 transcription in latently infected T-cell lines. Activation of the integrated HIV-1 promoter is accompanied by the loss or rearrangement of a positioned nucleosome (nuc-1) near the viral RNA start site. Here we show that TSA strongly induces HIV-1 transcription on chromatin in vitro, concomitant with an enhancer factor-assisted increase in the level of acetylated histone H4. TSA treatment, however, did not detectably alter enhancer factor binding or the positioning of nuc-1 on the majority of the chromatin templates indicating that protein acetylation and chromatin remodeling may be limiting steps that occur only on transcriptionally competent templates, or that remodeling of nuc-1 requires additional factors. To assess the number of active chromatin templates in vitro, transcription was limited to a single round with low levels of the detergent Sarkosyl. Remarkably, HIV-1 transcription on chromatin was found to arise from a small number of active templates that can each support nearly 100 rounds of transcription, and TSA increased the number of active templates in each round. In contrast, transcription on naked DNA was limited to only a few rounds and was not responsive to TSA. We conclude that HIV-1 enhancer complexes greatly facilitate transcription reinitiation on chromatin in vitro, and act at a limiting step to promote the acetylation of histones or other transcription factors required for HIV-1 enhancer activity. PMID:9407026

  4. APOBEC4 Enhances the Replication of HIV-1

    PubMed Central

    Hofmann, Henning; Hanschmann, Kay-Martin; Mühlebach, Michael D.; Schumann, Gerald G.; König, Renate; Cichutek, Klaus; Häussinger, Dieter; Münk, Carsten

    2016-01-01

    APOBEC4 (A4) is a member of the AID/APOBEC family of cytidine deaminases. In this study we found a high mRNA expression of A4 in human testis. In contrast, there were only low levels of A4 mRNA detectable in 293T, HeLa, Jurkat or A3.01 cells. Ectopic expression of A4 in HeLa cells resulted in mostly cytoplasmic localization of the protein. To test whether A4 has antiviral activity similar to that of proteins of the APOBEC3 (A3) subfamily, A4 was co-expressed in 293T cells with wild type HIV-1 and HIV-1 luciferase reporter viruses. We found that A4 did not inhibit the replication of HIV-1 but instead enhanced the production of HIV-1 in a dose-dependent manner and seemed to act on the viral LTR. A4 did not show detectable cytidine deamination activity in vitro and weakly interacted with single-stranded DNA. The presence of A4 in virus producer cells enhanced HIV-1 replication by transiently transfected A4 or stably expressed A4 in HIV-susceptible cells. APOBEC4 was capable of similarly enhancing transcription from a broad spectrum of promoters, regardless of whether they were viral or mammalian. We hypothesize that A4 may have a natural role in modulating host promoters or endogenous LTR promoters. PMID:27249646

  5. Human herpes virus-6 increases HIV-1 expression in co-infected T cells via nuclear factors binding to the HIV-1 enhancer.

    PubMed Central

    Ensoli, B; Lusso, P; Schachter, F; Josephs, S F; Rappaport, J; Negro, F; Gallo, R C; Wong-Staal, F

    1989-01-01

    Human Herpes virus-6 (HHV-6) can co-infect with HIV-1 human CD4+ T-cells, leading to accelerated cell death, and factors in HHV-6-infected cells stimulate HIV-1 LTR directed gene expression. In this study, we have examined the mechanism of HIV-1 activation by HHV-6 and localized the cis-acting sequences of HIV-1 LTR responsive to trans-activation. Increased HIV-1 LTR directed gene expression is obtained in HIV-1 infected cells co-infected with HHV-6, or in HHV-6 infected cells co-transfected with the HIV-1 tat gene. Parallel increases of HIV-1-specific transcripts are seen by in situ hybridization in HHV-6/HIV-1 doubly infected cells as compared to single HIV-1 infection. Similarly, infection by HHV-6 increases the steady-state level of HIV-1 LTR mRNA that parallels CAT enzymatic activity, suggesting a transcriptional and/or post-transcriptional activation. Sequences necessary for HIV-1 LTR activation by HHV-6 are distinct from those required for that tat response and map to a region of the HIV-1 LTR from -103 to -48. The HIV-1 enhancer sequence (-105 to -80) is sufficient to confer HHV-6 inducibility to a heterologous promoter, and nuclear protein(s) activated or induced by HHV-6 infection specifically bind to the NF kappa B motifs of the HIV-1 enhancer region.(ABSTRACT TRUNCATED AT 250 WORDS) Images PMID:2573513

  6. No SEVI-mediated enhancement of rectal HIV-1 transmission of HIV-1 in two humanized mouse cohorts.

    PubMed

    Van Dis, Erik S; Moore, Tyler C; Lavender, Kerry J; Messer, Ronald J; Keppler, Oliver T; Verheyen, Jens; Dittmer, Ulf; Hasenkrug, Kim J

    2016-01-15

    Amyloid fibrils from semen-derived peptide (SEVI) enhance HIV-1 infectivity in vitro but the ability of SEVI to mediate enhancement of HIV infection in vivo has not been tested. In this study we used immunodeficient mice reconstituted with human immune systems to test for in vivo enhancement of HIV-1 transmission. This mouse model supports mucosal transmission of HIV-1 via the intrarectal route leading to productive infection. In separate experiments with humanized mouse cohorts reconstituted with two different donor immune systems, high dose HIV-1JR-CSF that had been incubated with SEVI amyloid fibrils at physiologically relevant concentrations did not show an increased incidence of infection compared to controls. In addition, SEVI failed to enhance rectal transmission with a reduced concentration of HIV-1. Although we confirmed potent SEVI-mediated enhancement of HIV infectivity in vitro, this model showed no evidence that it plays a role in the much more complex situation of in vivo transmission. PMID:26609939

  7. Enhanced clearance of HIV-1-infected cells by broadly neutralizing antibodies against HIV-1 in vivo.

    PubMed

    Lu, Ching-Lan; Murakowski, Dariusz K; Bournazos, Stylianos; Schoofs, Till; Sarkar, Debolina; Halper-Stromberg, Ariel; Horwitz, Joshua A; Nogueira, Lilian; Golijanin, Jovana; Gazumyan, Anna; Ravetch, Jeffrey V; Caskey, Marina; Chakraborty, Arup K; Nussenzweig, Michel C

    2016-05-20

    Antiretroviral drugs and antibodies limit HIV-1 infection by interfering with the viral life cycle. In addition, antibodies also have the potential to guide host immune effector cells to kill HIV-1-infected cells. Examination of the kinetics of HIV-1 suppression in infected individuals by passively administered 3BNC117, a broadly neutralizing antibody, suggested that the effects of the antibody are not limited to free viral clearance and blocking new infection but also include acceleration of infected cell clearance. Consistent with these observations, we find that broadly neutralizing antibodies can target CD4(+) T cells infected with patient viruses and can decrease their in vivo half-lives by a mechanism that requires Fcγ receptor engagement in a humanized mouse model. The results indicate that passive immunotherapy can accelerate elimination of HIV-1-infected cells. PMID:27199430

  8. Glycosomal bromodomain factor 1 from Trypanosoma cruzi enhances trypomastigote cell infection and intracellular amastigote growth.

    PubMed

    Ritagliati, Carla; Villanova, Gabriela Vanina; Alonso, Victoria Lucia; Zuma, Aline Araujo; Cribb, Pamela; Motta, María Cristina Machado; Serra, Esteban Carlos

    2016-01-01

    Acetylation is a ubiquitous protein modification present in prokaryotic and eukaryotic cells that participates in the regulation of many cellular processes. The bromodomain is the only domain known to bind acetylated lysine residues. In the last few years, many bromodomain inhibitors have been developed in order to treat diseases caused by aberrant acetylation of lysine residues and have been tested as anti-parasitic drugs. In the present paper, we report the first characterization of Trypanosoma cruzi bromodomain factor 1 (TcBDF1). TcBDF1 is expressed in all life cycle stages, but it is developmentally regulated. It localizes in the glycosomes directed by a PTS2 (peroxisome-targeting signal 2) sequence. The overexpression of wild-type TcBDF1 is detrimental for epimastigotes, but it enhances the infectivity rate of trypomastigotes and the replication of amastigotes. On the other hand, the overexpression of a mutated version of TcBDF1 has no effect on epimastigotes, but it does negatively affect trypomastigotes' infection and amastigotes' replication.

  9. Deglycosylation of HIV-1 AE Gp140 enhances the capacity to elicit neutralizing antibodies against the heterologous HIV-1 clade.

    PubMed

    Zhang, Congyou; Wan, Yanmin; Shi, Jijing; Zhou, Mingzhe; Meng, Zhefeng; Yuan, Songhua; Qiu, Chao; Zhang, Xiaoyan; Xu, Xuemei; Liu, Chaoqi; Xu, Jianqing

    2010-05-01

    The aim of this study was to test whether deglycosylation of an HIV-1 AE recombinant-derived gp140 could enhance the induction of neutralizing antibodies. N-to-Q mutations were introduced in the V1/V2 (m157/161) or V4 (m382/388) loops by using overlapping PCR. BALB/c mice were inoculated with different DNA vaccines at weeks 0, 2, 4, and 7. The Elispot assay was used to quantify Env-specific T-cell immunity, and the TZM-bl cell-based in vitro neutralizing assay with primary isolates was used to assess humoral immune responses. Our data showed that two mutant DNA vaccines, designated m157/161 and m382/388, mounted total T-cell responses that were at levels similar those of the unmutated vaccine. Although the levels of binding antibodies elicited by the two mutants were significantly lower than the levels elicited by the unmutated vaccine, cross-reactive neutralizing antibodies were observed only in the sera that received the mutant DNA vaccines. These data demonstrate that deglycosylation of HIV-1 Env could enhance the capacity to elicit cross-reactive neutralizing antibodies. PMID:20455767

  10. Nef enhances HIV-1 infectivity via association with the virus assembly complex

    SciTech Connect

    Qi Mingli; Aiken, Christopher

    2008-04-10

    The HIV-1 accessory protein Nef enhances virus infectivity by facilitating an early post-entry step of infection. Nef acts in the virus producer cell, leading to a beneficial modification to HIV-1 particles. Nef itself is incorporated into HIV-1 particles, where it is cleaved by the viral protease during virion maturation. To probe the role of virion-associated Nef in HIV-1 infection, we generated a fusion protein consisting of the host protein cyclophilin A (CypA) linked to the amino terminus of Nef. The resulting CypA-Nef protein enhanced the infectivity of Nef-defective HIV-1 particles and was specifically incorporated into the virions via association with Gag during particle assembly. Pharmacologic or genetic inhibition of CypA-Nef binding to Gag prevented incorporation of CypA-Nef into virions and inhibited infectivity enhancement. Our results indicate that infectivity enhancement by Nef requires its association with a component of the assembling HIV-1 particle.

  11. HIV-1 Nef-associated Factor 1 Enhances Viral Production by Interacting with CRM1 to Promote Nuclear Export of Unspliced HIV-1 gag mRNA.

    PubMed

    Ren, Xiao-Xin; Wang, Hai-Bo; Li, Chuan; Jiang, Jin-Feng; Xiong, Si-Dong; Jin, Xia; Wu, Li; Wang, Jian-Hua

    2016-02-26

    HIV-1 depends on host-cell-encoded factors to complete its life cycle. A comprehensive understanding of how HIV-1 manipulates host machineries during viral infection can facilitate the identification of host targets for antiviral drugs or gene therapy. The cellular protein Naf1 (HIV-1 Nef-associated factor 1) is a CRM1-dependent nucleo-cytoplasmic shuttling protein, and has been identified to regulate multiple receptor-mediated signal pathways in inflammation. The cytoplasm-located Naf1 can inhibit NF-κB activation through binding to A20, and the loss of Naf1 controlled NF-κB activation is associated with multiple autoimmune diseases. However, the effect of Naf1 on HIV-1 mRNA expression has not been characterized. In this study we found that the nucleus-located Naf1 could promote nuclear export of unspliced HIV-1 gag mRNA. We demonstrated that the association between Naf1 and CRM1 was required for this function as the inhibition or knockdown of CRM1 expression significantly impaired Naf1-promoted HIV-1 production. The mutation of Naf1 nuclear export signals (NESs) that account for CRM1 recruitment for nuclear export decreased Naf1 function. Additionally, the mutation of the nuclear localization signal (NLS) of Naf1 diminished its ability to promote HIV-1 production, demonstrating that the shuttling property of Naf1 is required for this function. Our results reveal a novel role of Naf1 in enhancing HIV-1 production, and provide a potential therapeutic target for controlling HIV-1 infection.

  12. Mechanism of Multivalent Nanoparticle Encounter with HIV-1 for Potency Enhancement of Peptide Triazole Virus Inactivation*

    PubMed Central

    Rosemary Bastian, Arangassery; Nangarlia, Aakansha; Bailey, Lauren D.; Holmes, Andrew; Kalyana Sundaram, R. Venkat; Ang, Charles; Moreira, Diogo R. M.; Freedman, Kevin; Duffy, Caitlin; Contarino, Mark; Abrams, Cameron; Root, Michael; Chaiken, Irwin

    2015-01-01

    Entry of HIV-1 into host cells remains a compelling yet elusive target for developing agents to prevent infection. A peptide triazole (PT) class of entry inhibitor has previously been shown to bind to HIV-1 gp120, suppress interactions of the Env protein at host cell receptor binding sites, inhibit cell infection, and cause envelope spike protein breakdown, including gp120 shedding and, for some variants, virus membrane lysis. We found that gold nanoparticle-conjugated forms of peptide triazoles (AuNP-PT) exhibit substantially more potent antiviral effects against HIV-1 than corresponding peptide triazoles alone. Here, we sought to reveal the mechanism of potency enhancement underlying nanoparticle conjugate function. We found that altering the physical properties of the nanoparticle conjugate, by increasing the AuNP diameter and/or the density of PT conjugated on the AuNP surface, enhanced potency of infection inhibition to impressive picomolar levels. Further, compared with unconjugated PT, AuNP-PT was less susceptible to reduction of antiviral potency when the density of PT-competent Env spikes on the virus was reduced by incorporating a peptide-resistant mutant gp120. We conclude that potency enhancement of virolytic activity and corresponding irreversible HIV-1 inactivation of PTs upon AuNP conjugation derives from multivalent contact between the nanoconjugates and metastable Env spikes on the HIV-1 virus. The findings reveal that multispike engagement can exploit the metastability built into virus the envelope to irreversibly inactivate HIV-1 and provide a conceptual platform to design nanoparticle-based antiviral agents for HIV-1 specifically and putatively for metastable enveloped viruses generally. PMID:25371202

  13. Enhanced Heterosexual Transmission Hypothesis for the Origin of Pandemic HIV-1

    PubMed Central

    de Sousa, João Dinis; Alvarez, Carolina; Vandamme, Anne-Mieke; Müller, Viktor

    2012-01-01

    HIV-1 M originated from SIVcpz endemic in chimpanzees from southeast Cameroon or neighboring areas, and it started to spread in the early 20th century. Here we examine the factors that may have contributed to simian-to-human transmission, local transmission between humans, and export to a city. The region had intense ape hunting, social disruption, commercial sex work, STDs, and traffic to/from Kinshasa in the period 1899–1923. Injection treatments increased sharply around 1930; however, their frequency among local patients was far lower than among modern groups experiencing parenteral HIV-1 outbreaks. Recent molecular datings of HIV-1 M fit better the period of maximal resource exploitation and trade links than the period of high injection intensity. We conclude that although local parenteral outbreaks might have occurred, these are unlikely to have caused massive transmission. World War I led to additional, and hitherto unrecognized, risks of HIV-1 emergence. We propose an Enhanced Heterosexual Transmission Hypothesis for the origin of HIV-1 M, featuring at the time and place of its origin a coincidence of favorable co-factors (ape hunting, social disruption, STDs, and mobility) for both cross-species transmission and heterosexual spread. Our hypothesis does not exclude a role for parenteral transmission in the initial viral adaptation. PMID:23202448

  14. Crystal Structure of NFAT Bound to the HIV-1 LTR Tandem κB Enhancer Element

    SciTech Connect

    Bates, Darren L.; Barthel, Kristen K.B.; Wu, Yongqing; Kalhor, Reza; Stroud, James C.; Giffin, Michael J.; Chen, Lin

    2008-05-27

    Here, we have determined the crystal structure of the DNA binding domain of NFAT bound to the HIV-1 long terminal repeat (LTR) tandem {kappa}B enhancer element of 3.05 {angstrom} resolution. NFAT binds as a dimer to the upstream {kappa}B site (Core II), but as a monomer to the 3' end of the downstream {kappa}B site (Core I). The DNA shows a significant bend near the 5' end of Core I, where a lysine residue from NFAT bound to the 3' end of Core II inserts into the minor groove and seems to cause DNA bases to flip out. Consistent with this structural feature, the 5' end of Core I become hypersensitive to dimethylsulfate in the in vivo footprinting upon transcriptional activation of the HIV-1 LTR. Our studies provide a basis for futher investigating the functional mechanism of NFAT in HIV-1 transcription and replication.

  15. HIV-1 Transgenic Rat Prefrontal Cortex Hyper-Excitability is Enhanced by Cocaine Self-Administration.

    PubMed

    Wayman, Wesley N; Chen, Lihua; Hu, Xiu-Ti; Napier, T Celeste

    2016-07-01

    The medial prefrontal cortex (mPFC) is dysregulated in HIV-1-infected humans and the dysregulation is enhanced by cocaine abuse. Understanding mPFC pathophysiology in this comorbid state has been hampered by the dearth of relevant animal models. To help fill this knowledge gap, electrophysiological assessments were made of mPFC pyramidal neurons (PN) from adult male HIV-1 transgenic (Tg) F344 rats (which express seven of the nine HIV-1 toxic proteins) and non-Tg F344 rats that self-administered cocaine for 14 days (COC-SA), as well as saline-yoked controls (SAL-Yoked) and experimentally naive Tg and non-Tg rats. Forebrain slices were harvested and prepared for whole-cell patch-clamp recording, and in treated rats, this occurred after 14-18 days of forced abstinence. Aged-matched rats were used for immunohistochemical detection of the L-channel protein, Cav1.2-α1c. We determined that: (i) the two genotypes acquired the operant task and maintained similar levels of COC-SA, (ii) forced abstinence from COC-SA enhanced mPFC PN excitability in both genotypes, and neurons from Tg rats exhibited the greatest pathophysiology, (iii) neurons from SAL-Yoked Tg rats were more excitable than those from SAL-Yoked non-Tg rats, and in Tg rats (iv) blockade of L-type Ca(2+) channels reduced the enhanced excitability, and (v) Cav1.2-immunoreactivity was increased. These findings provide the first assessment of the mPFC pathophysiology in a rodent model of HIV-1-mediated neuropathology with and without cocaine self-administration. Outcomes reveal an enhanced cortical excitability during chronic exposure to HIV-1 proteins that is excessively exacerbated with cocaine abuse. Such neuropathophysiology may underlie the cognitive dysregulation reported for comorbid humans.

  16. Posttranscriptional m(6)A Editing of HIV-1 mRNAs Enhances Viral Gene Expression.

    PubMed

    Kennedy, Edward M; Bogerd, Hal P; Kornepati, Anand V R; Kang, Dong; Ghoshal, Delta; Marshall, Joy B; Poling, Brigid C; Tsai, Kevin; Gokhale, Nandan S; Horner, Stacy M; Cullen, Bryan R

    2016-05-11

    Covalent addition of a methyl group to adenosine N(6) (m(6)A) is an evolutionarily conserved and common RNA modification that is thought to modulate several aspects of RNA metabolism. While the presence of multiple m(6)A editing sites on diverse viral RNAs was reported starting almost 40 years ago, how m(6)A editing affects virus replication has remained unclear. Here, we used photo-crosslinking-assisted m(6)A sequencing techniques to precisely map several m(6)A editing sites on the HIV-1 genome and report that they cluster in the HIV-1 3' untranslated region (3' UTR). Viral 3' UTR m(6)A sites or analogous cellular m(6)A sites strongly enhanced mRNA expression in cis by recruiting the cellular YTHDF m(6)A "reader" proteins. Reducing YTHDF expression inhibited, while YTHDF overexpression enhanced, HIV-1 protein and RNA expression, and virus replication in CD4+ T cells. These data identify m(6)A editing and the resultant recruitment of YTHDF proteins as major positive regulators of HIV-1 mRNA expression. PMID:27117054

  17. Pro-inflammatory cytokines and HIV-1 synergistically enhance CXCL10 expression in human astrocytes

    PubMed Central

    Williams, Rachel; Dhillon, Navneet K.; Hegde, Sonia T.; Yao, Honghong; Peng, Fuwang; Callen, Shannon; Chebloune, Yahia; Davis, Randall L.; Buch, Shilpa J.

    2009-01-01

    HIV encephalitis (HIVE), the pathologic correlate of HIV-associated dementia (HAD) is characterized by astrogliosis, cytokine/chemokine dysregulation and neuronal degeneration. Increasing evidence suggests that inflammation is actively involved in the pathogenesis of HAD. In fact, the severity of HAD/HIVE correlates more closely with the presence of activated glial cells than with the presence and amount of HIV-infected cells in the brain. Astrocytes, the most numerous cell type within the brain, provide an important reservoir for the generation of inflammatory mediators, including interferon-γ inducible peptide-10 (CXCL10), a neurotoxin and a chemoattractant, implicated in the pathophysiology of HAD. Additionally, the pro-inflammatory cytokines, IFN-γ and TNF-α, are also markedly increased in CNS tissues during HIV-1 infection. In the present study we hypothesized that the interplay of host cytokines and HIV-1 could lead to enhanced expression of the toxic chemokine, CXCL10. Our findings demonstrate a synergistic induction of CXCL10 mRNA and protein in human astrocytes exposed to HIV-1 and the pro-inflammatory cytokines. Signaling molecules, including JAK, STATs, MAPK (via activation of Erk1/2, AKT, and p38), and NF-κB were identified as instrumental in the synergistic induction of CXCL10. Understanding the mechanisms involved in HIV-1 and cytokine mediated up-regulation of CXCL10 could aid in the development of therapeutic modalities for HAD. PMID:18985732

  18. Nonhuman TRIM5 Variants Enhance Recognition of HIV-1-Infected Cells by CD8+ T Cells

    PubMed Central

    Jimenez-Moyano, Esther; Ruiz, Alba; Kløverpris, Henrik N.; Rodriguez-Plata, Maria T.; Peña, Ruth; Blondeau, Caroline; Selwood, David L.; Izquierdo-Useros, Nuria; Moris, Arnaud; Clotet, Bonaventura; Goulder, Philip; Towers, Greg J.

    2016-01-01

    ABSTRACT Tripartite motif-containing protein 5 (TRIM5) restricts human immunodeficiency virus type 1 (HIV-1) in a species-specific manner by uncoating viral particles while activating early innate responses. Although the contribution of TRIM5 proteins to cellular immunity has not yet been studied, their interactions with the incoming viral capsid and the cellular proteasome led us to hypothesize a role for them. Here, we investigate whether the expression of two nonhuman TRIM5 orthologs, rhesus TRIM5α (RhT5) and TRIM-cyclophilin A (TCyp), both of which are potent restrictors of HIV-1, could enhance immune recognition of infected cells by CD8+ T cells. We illustrate how TRIM5 restriction improves CD8+ T-cell-mediated HIV-1 inhibition. Moreover, when TRIM5 activity was blocked by the nonimmunosuppressive analog of cyclosporine (CsA), sarcosine-3(4-methylbenzoate)–CsA (SmBz-CsA), we found a significant reduction in CD107a/MIP-1β expression in HIV-1-specific CD8+ T cells. This finding underscores the direct link between TRIM5 restriction and activation of CD8+ T-cell responses. Interestingly, cells expressing RhT5 induced stronger CD8+ T-cell responses through the specific recognition of the HIV-1 capsid by the immune system. The underlying mechanism of this process may involve TRIM5-specific capsid recruitment to cellular proteasomes and increase peptide availability for loading and presentation of HLA class I antigens. In summary, we identified a novel function for nonhuman TRIM5 variants in cellular immunity. We hypothesize that TRIM5 can couple innate viral sensing and CD8+ T-cell activation to increase species barriers against retrovirus infection. IMPORTANCE New therapeutics to tackle HIV-1 infection should aim to combine rapid innate viral sensing and cellular immune recognition. Such strategies could prevent seeding of the viral reservoir and the immune damage that occurs during acute infection. The nonhuman TRIM5 variants, rhesus TRIM5α (RhT5) and TRIM

  19. Blocking CXCL9 Decreases HIV-1 Replication and Enhances the Activity of Prophylactic Antiretrovirals in Human Cervical Tissues

    PubMed Central

    Macura, Sherrill L.; Lathrop, Melissa J.; Gui, Jiang; Doncel, Gustavo F.; Rollenhagen, Christiane

    2016-01-01

    Objectives: The interferon-gamma–induced chemokine CXCL9 is expressed in a wide range of inflammatory conditions including those affecting the female genital tract. CXCL9 promotes immune cell recruitment, activation, and proliferation. The role of CXCL9 in modulating HIV-1 infection of cervicovaginal tissues, a main portal of viral entry, however, has not been established. We report a link between CXCL9 and HIV-1 replication in human cervical tissues and propose CXCL9 as a potential target to enhance the anti–HIV-1 activity of prophylactic antiretrovirals. Design: Using ex vivo infection of human cervical tissues as a model of mucosal HIV-1 acquisition, we described the effect of CXCL9 neutralization on HIV-1 gene expression and mucosal CD4+ T-cell activation. The anti-HIV-1 activity of tenofovir, the leading mucosal pre-exposure prophylactic microbicide, alone or in combination with CXCL9 neutralization was also studied. Methods: HIV-1 replication was evaluated by p24 ELISA. HIV-1 DNA and RNA, and CD4, CCR5, and CD38 transcription were evaluated by quantitative real-time polymerase chain reaction. Frequency of activated cervical CD4+ T cells was quantified using fluorescence-activated cell sorting. Results: Antibody blocking of CXCL9 reduced HIV-1 replication by decreasing mucosal CD4+ T-cell activation. CXCL9 neutralization in combination with suboptimal concentrations of tenofovir, possibly present in the cervicovaginal tissues of women using the drug inconsistently, demonstrated an earlier and greater decrease in HIV-1 replication compared with tissues treated with tenofovir alone. Conclusions: CXCL9 neutralization reduces HIV-1 replication and may be an effective target to enhance the efficacy of prophylactic antiretrovirals. PMID:26545124

  20. HIV-1 Tat Protein Enhances Expression and Function of Breast Cancer Resistance Protein.

    PubMed

    Zhou, Yancong; Zhang, Kun; Yin, Xiaojie; Nie, Qichang; Ma, Yonggang

    2016-01-01

    ATP binding cassette (ABC) transporters can transfer a variety of antiviral agents from the cytoplasm to body fluid, which results in a reduced intracellular concentration of the drugs. Proteins of HIV-1, e.g., Tat and gp120, altered some types of ABC transporter expression in brain microvascular endothelial cells and astrocytes. However, the effect of Tat on ABC transporters in T lymphocytes is unclear. In this study the status of breast cancer resistance protein (BCRP) in Tat expressing cell lines was examined with real-time PCR and flow cytometry. It was found that HIV-1 Tat protein upregulated BCRP expression and enhanced efflux mediated by BCRP significantly, which could inhibit antiviral drugs from entering infected cells and interfere with the therapeutic effect of HAART. PMID:26367065

  1. Enhanced HIV-1 neutralization by a CD4-VH3-IgG1 fusion protein

    SciTech Connect

    Meyuhas, Ronit; Noy, Hava; Fishman, Sigal; Margalit, Alon; Montefiori, David C.; Gross, Gideon

    2009-08-21

    HIV-1 gp120 is an alleged B cell superantigen, binding certain VH3+ human antibodies. We reasoned that a CD4-VH3 fusion protein could possess higher affinity for gp120 and improved HIV-1 inhibitory capacity. To test this we produced several human IgG1 immunoligands harboring VH3. Unlike VH3-IgG1 or VH3-CD4-IgG1, CD4-VH3-IgG1 bound gp120 considerably stronger than CD4-IgG1. CD4-VH3-IgG1 exhibited {approx}1.5-2.5-fold increase in neutralization of two T-cell laboratory-adapted strains when compared to CD4-IgG1. CD4-VH3-IgG1 improved neutralization of 7/10 clade B primary isolates or pseudoviruses, exceeding 20-fold for JR-FL and 13-fold for Ba-L. It enhanced neutralization of 4/8 clade C viruses, and had negligible effect on 1/4 clade A pseudoviruses. We attribute this improvement to possible pairing of VH3 with CD4 D1 and stabilization of an Ig Fv-like structure, rather than to superantigen interactions. These novel findings support the current notion that CD4 fusion proteins can act as better HIV-1 entry inhibitors with potential clinical implications.

  2. HIV-1 Tat protein enhances the intracellular growth of Leishmania amazonensis via the ds-RNA induced protein PKR

    PubMed Central

    Vivarini, Áislan de Carvalho; Santos Pereira, Renata de Meirelles; Barreto-de-Souza, Victor; Temerozo, Jairo Ramos; Soares, Deivid C.; Saraiva, Elvira M.; Saliba, Alessandra Mattos; Bou-Habib, Dumith Chequer; Lopes, Ulisses Gazos

    2015-01-01

    HIV-1 co-infection with human parasitic diseases is a growing public health problem worldwide. Leishmania parasites infect and replicate inside macrophages, thereby subverting host signaling pathways, including the response mediated by PKR. The HIV-1 Tat protein interacts with PKR and plays a pivotal role in HIV-1 replication. This study shows that Tat increases both the expression and activation of PKR in Leishmania-infected macrophages. Importantly, the positive effect of Tat addition on parasite growth was dependent on PKR signaling, as demonstrated in PKR-deficient macrophages or macrophages treated with the PKR inhibitor. The effect of HIV-1 Tat on parasite growth was prevented when the supernatant of HIV-1-infected macrophages was treated with neutralizing anti-HIV-1 Tat prior to Leishmania infection. The addition of HIV-1 Tat to Leishmania-infected macrophages led to inhibition of iNOS expression, modulation of NF-kB activation and enhancement of IL-10 expression. Accordingly, the expression of a Tat construct containing mutations in the basic region (49–57aa), which is responsible for the interaction with PKR, favored neither parasite growth nor IL-10 expression in infected macrophages. In summary, we show that Tat enhances Leishmania growth through PKR signaling. PMID:26608746

  3. HIV-1 Nef Is Transferred from Expressing T Cells to Hepatocytic Cells through Conduits and Enhances HCV Replication

    PubMed Central

    Park, In-Woo; Fan, Yan; Luo, Xiaoyu; Ryou, Myoung-Gwi; Liu, Jinfeng; Green, Linden; He, Johnny J.

    2014-01-01

    HIV-1 infection enhances HCV replication and as a consequence accelerates HCV-mediated hepatocellular carcinoma (HCC). However, the precise molecular mechanism by which this takes place is currently unknown. Our data showed that infectious HIV-1 failed to replicate in human hepatocytic cell lines. No discernible virus replication was observed, even when the cell lines transfected with HIV-1 proviral DNA were co-cultured with Jurkat T cells, indicating that the problem of liver deterioration in the co-infected patient is not due to the replication of HIV-1 in the hepatocytes of the HCV infected host. Instead, HIV-1 Nef protein was transferred from nef-expressing T cells to hepatocytic cells through conduits, wherein up to 16% (average 10%) of the cells harbored the transferred Nef, when the hepatocytic cells were co-cultured with nef-expressing Jurkat cells for 24 h. Further, Nef altered the size and numbers of lipid droplets (LD), and consistently up-regulated HCV replication by 1.5∼2.5 fold in the target subgenomic replicon cells, which is remarkable in relation to the initially indolent viral replication. Nef also dramatically augmented reactive oxygen species (ROS) production and enhanced ethanol-mediated up-regulation of HCV replication so as to accelerate HCC. Taken together, these data indicate that HIV-1 Nef is a critical element in accelerating progression of liver pathogenesis via enhancing HCV replication and coordinating modulation of key intra- and extra-cellular molecules for liver decay. PMID:24911518

  4. Enhancement of viral escape in HIV-1 Nef by STEP vaccination

    PubMed Central

    Park, Sung Yong; Mack, Wendy J.; Lee, Ha Y.

    2016-01-01

    Objective: Properly priming cytotoxic T-lymphocyte (CTL) responses is an important task in HIV-1 vaccination. However, the STEP trial showed no efficacy even though the vaccine elicited HIV-specific CTL responses. Our study is to investigate whether or not the STEP vaccine enhanced viral escape in infected volunteers. Methods: The signature of viral escape, the presence of multiple escape variants, could be falsely represented by the existence of multiple founder viruses. Therefore, we use a mathematical model to designate STEP study patients with infections from a single founder virus. We then conduct permutation tests on each of 9988 Gag, Pol, and Nef overlapping peptides to identify epitopes with significant differences in diversity between the vaccine and placebo groups using previously published STEP trial sequence data. Results: We identify signatures of vaccine-enhanced viral escape within HIV-1 Nef from the STEP trial. Vaccine-treated patients showed a greater level of epitope diversity in one of the immunodomiant epitopes, EVGFPVRPQVPL (Nef65–76), compared with placebo-treated patients (P = 0.0038). In the other three Nef epitopes, there is a marginally significant difference in the epitope diversity between the vaccine and placebo group (P < 0.1). This greater epitope diversity was neither due to any difference in infection duration nor overall nef gene diversity between the two groups, suggesting that the increase in viral escape was likely mediated by vaccine-induced T-cell responses. Conclusion: Viral escape in Nef is elevated preferentially in STEP vaccine-treated individuals, suggesting that vaccination primarily modulated initial CTL responses. Our observations provide important insights into improving vaccine-primed first immune control. PMID:27427874

  5. Enhanced Potency of a Broadly Neutralizing HIV-1 Antibody In Vitro Improves Protection against Lentiviral Infection In Vivo

    PubMed Central

    Rudicell, Rebecca S.; Kwon, Young Do; Ko, Sung-Youl; Pegu, Amarendra; Louder, Mark K.; Georgiev, Ivelin S.; Wu, Xueling; Zhu, Jiang; Boyington, Jeffrey C.; Chen, Xuejun; Shi, Wei; Yang, Zhi-yong; Doria-Rose, Nicole A.; McKee, Krisha; O'Dell, Sijy; Schmidt, Stephen D.; Chuang, Gwo-Yu; Druz, Aliaksandr; Soto, Cinque; Yang, Yongping; Zhang, Baoshan; Zhou, Tongqing; Todd, John-Paul; Lloyd, Krissey E.; Eudailey, Joshua; Roberts, Kyle E.; Donald, Bruce R.; Bailer, Robert T.; Ledgerwood, Julie; Mullikin, James C.; Shapiro, Lawrence; Koup, Richard A.; Graham, Barney S.; Nason, Martha C.; Connors, Mark; Haynes, Barton F.; Rao, Srinivas S.; Roederer, Mario; Kwong, Peter D.

    2014-01-01

    ABSTRACT Over the past 5 years, a new generation of highly potent and broadly neutralizing HIV-1 antibodies has been identified. These antibodies can protect against lentiviral infection in nonhuman primates (NHPs), suggesting that passive antibody transfer would prevent HIV-1 transmission in humans. To increase the protective efficacy of such monoclonal antibodies, we employed next-generation sequencing, computational bioinformatics, and structure-guided design to enhance the neutralization potency and breadth of VRC01, an antibody that targets the CD4 binding site of the HIV-1 envelope. One variant, VRC07-523, was 5- to 8-fold more potent than VRC01, neutralized 96% of viruses tested, and displayed minimal autoreactivity. To compare its protective efficacy to that of VRC01 in vivo, we performed a series of simian-human immunodeficiency virus (SHIV) challenge experiments in nonhuman primates and calculated the doses of VRC07-523 and VRC01 that provide 50% protection (EC50). VRC07-523 prevented infection in NHPs at a 5-fold lower concentration than VRC01. These results suggest that increased neutralization potency in vitro correlates with improved protection against infection in vivo, documenting the improved functional efficacy of VRC07-523 and its potential clinical relevance for protecting against HIV-1 infection in humans. IMPORTANCE In the absence of an effective HIV-1 vaccine, alternative strategies are needed to block HIV-1 transmission. Direct administration of HIV-1-neutralizing antibodies may be able to prevent HIV-1 infections in humans. This approach could be especially useful in individuals at high risk for contracting HIV-1 and could be used together with antiretroviral drugs to prevent infection. To optimize the chance of success, such antibodies can be modified to improve their potency, breadth, and in vivo half-life. Here, knowledge of the structure of a potent neutralizing antibody, VRC01, that targets the CD4-binding site of the HIV-1 envelope

  6. Morphine Enhances HIV-1SF162-Mediated Neuron Death and Delays Recovery of Injured Neurites

    PubMed Central

    Masvekar, Ruturaj R.; El-Hage, Nazira; Hauser, Kurt F.; Knapp, Pamela E.

    2014-01-01

    HIV-1 enters the CNS soon after initial systemic infection; within the CNS parenchyma infected and/or activated perivascular macrophages, microglia and astrocytes release viral and cellular toxins that drive secondary toxicity in neurons and other cell types. Our previous work has largely modeled HIV-neuropathology using the individual viral proteins Tat or gp120, with murine striatal neurons as targets. To model disease processes more closely, the current study uses supernatant from HIV-1-infected cells. Supernatant from HIV-1SF162-infected differentiated-U937 cells (HIV+sup) was collected and p24 level was measured by ELISA to assess the infection. Injection drug abuse is a significant risk factor for HIV-infection, and opiate drug abusers show increased HIV-neuropathology, even with anti-retroviral treatments. We therefore assessed HIV+sup effects on neuronal survival and neurite growth/pruning with or without concurrent exposure to morphine, an opiate that preferentially acts through µ-opioid receptors. Effects of HIV+sup ± morphine were assessed on neuronal populations, and also by time-lapse imaging of individual cells. HIV+sup caused dose-dependent toxicity over a range of p24 levels (10–500 pg/ml). Significant interactions occurred with morphine at lower p24 levels (10 and 25 pg/ml), and GSK3β was implicated as a point of convergence. In the presence of glia, selective neurotoxic measures were significantly enhanced and interactions with morphine were also augmented, perhaps related to a decreased level of BDNF. Importantly, the arrest of neurite growth that occurred with exposure to HIV+sup was reversible unless neurons were continuously exposed to morphine. Thus, while reducing HIV-infection levels may be protective, ongoing exposure to opiates may limit recovery. Opiate interactions observed in this HIV-infective environment were similar, though not entirely concordant, with Tat/gp120 interactions reported previously, suggesting unique interactions

  7. Polyanionic Candidate Microbicides Accelerate the Formation of Semen-Derived Amyloid Fibrils to Enhance HIV-1 Infection

    PubMed Central

    Tan, Suiyi; Lu, Lu; Li, Lin; Liu, Jixiang; Oksov, Yelena; Lu, Hong; Jiang, Shibo; Liu, Shuwen

    2013-01-01

    Polyanionic candidate microbicides, including cellulose sulfate, carrageenan, PRO 2000, were proven ineffective in preventing HIV-1 transmission and even cellulose sulfate showed increased risk of HIV acquisition in the Phase III efficacy trials. Semen plays critical roles in HIV-1 sexual transmission. Specifically, amyloid fibrils formed by fragments of prostatic acidic phosphatase (PAP) in semen termed semen-derived enhancer of virus infection (SEVI) could drastically enhance HIV-1 infection. Here we investigated the interaction between polyanions and PAP248-286, a prototype peptide of SEVI, to understand the possible cause of polyanionic candidate microbicides to fail in clinical trials. We found anionic polymers could efficiently promote SEVI fibril formation, most likely mediated by the natural electrostatic interaction between polyanions and PAP248-286, as revealed by acid native PAGE and Western blot. The overall anti-HIV-1 activity of polyanions in the presence or absence of PAP248-286 or semen was evaluated. In the viral infection assay, the supernatants of polyanions/PAP248-286 or polyanions/semen mixtures containing the free, unbound polyanionic molecules showed a general reduction in antiviral efficacy, while the pellets containing amyloid fibrils formed by the polyanion-bound PAP248-286 showed aggravated enhancement of viral infection. Collectively, from the point of drug-host protein interaction, our study revealed that polyanions facilitate SEVI fibril formation to promote HIV-1 infection, thus highlighting a molecular mechanism underlying the failure of polyanions in clinical trials and the importance of drug-semen interaction in evaluating the anti-HIV-1 efficacy of candidate microbicides. PMID:23544097

  8. Cocaine enhances HIV-1-induced CD4(+) T-cell apoptosis: implications in disease progression in cocaine-abusing HIV-1 patients.

    PubMed

    Pandhare, Jui; Addai, Amma B; Mantri, Chinmay K; Hager, Cynthia; Smith, Rita M; Barnett, Louis; Villalta, Fernando; Kalams, Spyros A; Dash, Chandravanu

    2014-04-01

    Substance abuse is a major barrier in eradication of the HIV epidemic because it serves as a powerful cofactor for viral transmission, disease progression, and AIDS-related mortality. Cocaine, one of the commonly abused drugs among HIV-1 patients, has been suggested to accelerate HIV disease progression. However, the underlying mechanism remains largely unknown. Therefore, we tested whether cocaine augments HIV-1-associated CD4(+) T-cell decline, a predictor of HIV disease progression. We examined apoptosis of resting CD4(+) T cells from HIV-1-negative and HIV-1-positive donors in our study, because decline of uninfected cells plays a major role in HIV-1 disease progression. Treatment of resting CD4(+) T cells with cocaine (up to 100 μmol/L concentrations) did not induce apoptosis, but 200 to 1000 μmol/L cocaine induced apoptosis in a dose-dependent manner. Notably, treatment of CD4(+) T cells isolated from healthy donors with both HIV-1 virions and cocaine significantly increased apoptosis compared with the apoptosis induced by cocaine or virions alone. Most important, our biochemical data suggest that cocaine induces CD4(+) T-cell apoptosis by increasing intracellular reactive oxygen species levels and inducing mitochondrial depolarization. Collectively, our results provide evidence of a synergy between cocaine and HIV-1 on CD4(+) T-cell apoptosis that may, in part, explain the accelerated disease observed in HIV-1-infected drug abusers.

  9. Gallic Acid Is an Antagonist of Semen Amyloid Fibrils That Enhance HIV-1 Infection.

    PubMed

    LoRicco, Josephine G; Xu, Changmingzi Sherry; Neidleman, Jason; Bergkvist, Magnus; Greene, Warner C; Roan, Nadia R; Makhatadze, George I

    2016-07-01

    Recent in vitro studies have demonstrated that amyloid fibrils found in semen from healthy and HIV-infected men, as well as semen itself, can markedly enhance HIV infection rates. Semen fibrils are made up of multiple naturally occurring peptide fragments derived from semen. The best characterized of these fibrils are SEVI (semen-derived enhancer of viral infection), made up of residues 248-286 of prostatic acidic phosphatase, and the SEM1 fibrils, made up of residues 86-107 of semenogelin 1. A small molecule screen for antagonists of semen fibrils identified four compounds that lowered semen-mediated enhancement of HIV-1 infectivity. One of the four, gallic acid, was previously reported to antagonize other amyloids and to exert anti-inflammatory effects. To better understand the mechanism by which gallic acid modifies the properties of semen amyloids, we performed biophysical measurements (atomic force microscopy, electron microscopy, confocal microscopy, thioflavin T and Congo Red fluorescence assays, zeta potential measurements) and quantitative assays on the effects of gallic acid on semen-mediated enhancement of HIV infection and inflammation. Our results demonstrate that gallic acid binds to both SEVI and SEM1 fibrils and modifies their surface electrostatics to render them less cationic. In addition, gallic acid decreased semen-mediated enhancement of HIV infection but did not decrease the inflammatory response induced by semen. Together, these observations identify gallic acid as a non-polyanionic compound that inhibits semen-mediated enhancement of HIV infection and suggest the potential utility of incorporating gallic acid into a multicomponent microbicide targeting both the HIV virus and host components that promote viral infection.

  10. Enhancing of anti-viral activity against HIV-1 by stimulation of CD8+ T cells with thymic peptides

    PubMed Central

    MÜLLER, H; MAYER, G; BEHNKE, B; HEIMÜLLER, E; HAMSCHER, G; IMMLER, D; SIETHOFF, C; MEYER, HE; SCHREIBER, M

    1999-01-01

    HIV-1 can be neutralized by soluble factors produced and secreted by activated CD8+ T cells. Production of such anti-viral CD8 factors (including chemokines) can be induced with IL-2 or phytohaemagglutinin (PHA). In addition to PHA or IL-2, we have co-stimulated CD8+ T cells with PHA/IL-2 and a mixture of thymic peptides (TP) of molecular weights below 10 kD. For the activation, CD8+ T cells were purified from peripheral blood mononuclear cells of HIV-1− individuals and any resultant anti-viral activity was monitored using an HIV-1 neutralization assay. Using HIV-1 isolates highly resistant to chemokine inhibition we detected significantly higher levels of HIV-1 neutralizing activity in CD8+ T cell culture supernatants which had been co-activated with TP. When the TP-induced anti-viral activity was monitored, neutralization of both non-syncytia-inducing (NSI) and syncytia-inducing (SI) patient isolates was enhanced by 38% (NSI, PHA +/− TP), 66% (SI, PHA +/− TP), 28% (NSI, IL-2 +/− TP), and 57% (SI, IL-2 +/− TP) compared with the anti-viral activity present in supernatants from CD8+ T cell cultures stimulated only with PHA or IL-2. Peptide sequence analysis of purified TP showed that the TP mixture predominantly contains peptides with homology to human histone and collagen sequences. Our data demonstrate that CD8+ T cells are additionally activated by a mixture of TP. In this way, the production of HIV-1 neutralizing CD8 factors can be enhanced. PMID:10403919

  11. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    SciTech Connect

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang; Liu, Yan-Hong; Li, Yan; Wang, Jia-Ye; Hattori, Toshio; Ling, Hong; Zhang, Feng-Min

    2010-01-22

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  12. Nucleocapsid Protein Annealing of a Primer-Template Enhances (+)-Strand DNA Synthesis and Fidelity by HIV-1 Reverse Transcriptase†

    PubMed Central

    Kim, Jiae; Roberts, Anne; Yuan, Hua; Xiong, Yong; Anderson, Karen S.

    2012-01-01

    Human immunodeficiency virus type-1 (HIV-1) requires reverse transcriptase (RT) and HIV-1 nucleocapsid protein (NCp7) for proper viral replication. HIV-1 NCp7 has been shown to enhance various steps in reverse transcription including tRNA initiation and strand transfer which may be mediated through interactions with RT as well as RNA and DNA oligonucleotides. With the use of DNA oligonucleotides, we have examined the interaction of NCp7 with RT and the kinetics of reverse transcription during (+)-strand synthesis with an NCp7-facilitated annealed primer-template. Using a pre-steady state kinetics approach, the NCp7-annealed primer-template has a substantial increase (3-7 fold) in the rate of incorporation (kpol) by RT as compared to heat annealed primer-template with single nucleotide incorporation. There was also a 2-fold increase in the binding affinity constant (Kd) of the nucleotide. These differences in kpol and Kd were not through direct interactions between HIV-1 RT and NCp7. When examining extension by RT, the data suggests that the NCp7-annealed primer-template facilitates the formation of a longer product more quickly compared to the heat annealed primer-template. This enhancement in rate is mediated through interactions with NCp7’s zinc fingers and N-terminal domain and nucleic acids. The NCp7-annealed primer-template also enhances the fidelity of RT (3-fold) by slowing the rate of incorporation of an incorrect nucleotide. Taken together, this study elucidates a new role of NCp7 by facilitating DNA-directed DNA synthesis during reverse transcription by HIV-1 RT that may translate into enhanced viral fitness and offers an avenue to exploit for targeted therapeutic intervention against HIV. PMID:22210155

  13. Maturation of the viral core enhances the fusion of HIV-1 particles with primary human T cells and monocyte-derived macrophages

    SciTech Connect

    Jiang Jiyang; Aiken, Christopher . E-mail: chris.aiken@vanderbilt.edu

    2006-03-15

    HIV-1 infection requires fusion of viral and cellular membranes in a reaction catalyzed by the viral envelope proteins gp120 and gp41. We recently reported that efficient HIV-1 particle fusion with target cells is linked to maturation of the viral core by an activity of the gp41 cytoplasmic domain. Here, we show that maturation enhances the fusion of a variety of recombinant viruses bearing primary and laboratory-adapted Env proteins with primary human CD4{sup +} T cells. Overall, HIV-1 fusion was more dependent on maturation for viruses bearing X4-tropic envelope proteins than for R5-tropic viruses. Fusion of HIV-1 with monocyte-derived macrophages was also dependent on particle maturation. We conclude that the ability to couple fusion to particle maturation is a common feature of HIV-1 Env proteins and may play an important role during HIV-1 replication in vivo.

  14. 5-Azacytidine Enhances the Mutagenesis of HIV-1 by Reduction to 5-Aza-2′-Deoxycytidine

    PubMed Central

    Rawson, Jonathan M. O.; Daly, Michele B.; Xie, Jiashu; Clouser, Christine L.; Landman, Sean R.; Reilly, Cavan S.; Bonnac, Laurent; Kim, Baek; Patterson, Steven E.

    2016-01-01

    5-Azacytidine (5-aza-C) is a ribonucleoside analog that induces the lethal mutagenesis of human immunodeficiency virus type 1 (HIV-1) by causing predominantly G-to-C transversions during reverse transcription. 5-Aza-C could potentially act primarily as a ribonucleotide (5-aza-CTP) or as a deoxyribonucleotide (5-aza-2′-deoxycytidine triphosphate [5-aza-dCTP]) during reverse transcription. In order to determine the primary form of 5-aza-C that is active against HIV-1, Illumina sequencing was performed using proviral DNA from cells treated with 5-aza-C or 5-aza-dC. 5-Aza-C and 5-aza-dC were found to induce highly similar patterns of mutation in HIV-1 in terms of the types of mutations observed, the magnitudes of effects, and the distributions of mutations at individual sequence positions. Further, 5-aza-dCTP was detected by liquid chromatography–tandem mass spectrometry in cells treated with 5-aza-C, demonstrating that 5-aza-C was a substrate for ribonucleotide reductase. Notably, levels of 5-aza-dCTP were similar in cells treated with equivalent effective concentrations of 5-aza-C or 5-aza-dC. Lastly, HIV-1 reverse transcriptase was found to incorporate 5-aza-CTP in vitro at least 10,000-fold less efficiently than 5-aza-dCTP. Taken together, these data support the model that 5-aza-C enhances the mutagenesis of HIV-1 primarily after reduction to 5-aza-dC, which can then be incorporated during reverse transcription and lead to G-to-C hypermutation. These findings may have important implications for the design of new ribonucleoside analogs directed against retroviruses. PMID:26833151

  15. A Novel Toll-Like Receptor 9 Agonist, MGN1703, Enhances HIV-1 Transcription and NK Cell-Mediated Inhibition of HIV-1-Infected Autologous CD4+ T Cells

    PubMed Central

    Nissen, Sara Konstantin; Rasmussen, Thomas A.; Østergaard, Lars; Denton, Paul W.; Søgaard, Ole Schmeltz

    2016-01-01

    ABSTRACT Toll-like receptor (TLR) agonists are potent enhancers of innate antiviral immunity and may also reverse HIV-1 latency. Therefore, TLR agonists have a potential role in the context of a “shock-and-kill” approach to eradicate HIV-1. Our extensive preclinical evaluation suggests that a novel TLR9 agonist, MGN1703, may indeed perform both functions in an HIV-1 eradication trial. Peripheral blood mononuclear cells (PBMCs) from aviremic HIV-1-infected donors on antiretroviral therapy (ART) that were incubated with MGN1703 ex vivo exhibited increased secretion of interferon alpha (IFN-α) (P = 0.005) and CXCL10 (P = 0.0005) in culture supernatants. Within the incubated PBMC pool, there were higher proportions of CD69-positive CD56dim CD16+ NK cells (P = 0.001) as well as higher proportions of CD107a-positive (P = 0.002) and IFN-γ-producing (P = 0.038) NK cells. Incubation with MGN1703 also increased the proportions of CD69-expressing CD4+ and CD8+ T cells. Furthermore, CD4+ T cells within the pool of MGN1703-incubated PBMCs showed enhanced levels of unspliced HIV-1 RNA (P = 0.036). Importantly, MGN1703 increased the capacity of NK cells to inhibit virus spread within a culture of autologous CD4+ T cells assessed by using an HIV-1 p24 enzyme-linked immunosorbent assay (ELISA) (P = 0.03). In conclusion, we show that MGN1703 induced strong antiviral innate immune responses, enhanced HIV-1 transcription, and boosted NK cell-mediated suppression of HIV-1 infection in autologous CD4+ T cells. These findings support clinical testing of MGN1703 in HIV-1 eradication trials. IMPORTANCE We demonstrate that MGN1703 (a TLR9 agonist currently undergoing phase 3 clinical testing for the treatment of metastatic colorectal cancer) induces potent antiviral responses in immune effector cells from HIV-1-infected individuals on suppressive antiretroviral therapy. The significantly improved safety and tolerability profiles of MGN1703 versus TLR9 agonists of the Cp

  16. Hepatitis C virus core protein enhances HIV-1 replication in human macrophages through TLR2, JNK, and MEK1/2-dependent upregulation of TNF-α and IL-6.

    PubMed

    Swaminathan, Gokul; Pascual, Daniel; Rival, Germaine; Perales-Linares, Renzo; Martin-Garcia, Julio; Navas-Martin, Sonia

    2014-09-17

    Despite their differential cell tropisms, HIV-1 and HCV dramatically influence disease progression in coinfected patients. Macrophages are important target cells of HIV-1. We hypothesized that secreted HCV core protein might modulate HIV-1 replication. We demonstrate that HCV core significantly enhances HIV-1 replication in human macrophages by upregulating TNF-α and IL-6 via TLR2-, JNK-, and MEK1/2-dependent pathways. Furthermore, we show that TNF-α and IL-6 secreted from HCV core-treated macrophages reactivates monocytic U1 cells latently infected with HIV-1. Our studies reveal a previously unrecognized role of HCV core by enhancing HIV-1 infection in macrophages.

  17. Vpr Enhances Tumor Necrosis Factor Production by HIV-1-Infected T Cells

    PubMed Central

    Roesch, Ferdinand; Richard, Léa; Rua, Réjane; Porrot, Françoise; Casartelli, Nicoletta

    2015-01-01

    ABSTRACT The HIV-1 accessory protein Vpr displays different activities potentially impacting viral replication, including the arrest of the cell cycle in the G2 phase and the stimulation of apoptosis and DNA damage response pathways. Vpr also modulates cytokine production by infected cells, but this property remains partly characterized. Here, we investigated the effect of Vpr on the production of the proinflammatory cytokine tumor necrosis factor (TNF). We report that Vpr significantly increases TNF secretion by infected lymphocytes. De novo production of Vpr is required for this effect. Vpr mutants known to be defective for G2 cell cycle arrest induce lower levels of TNF secretion, suggesting a link between these two functions. Silencing experiments and the use of chemical inhibitors further implicated the cellular proteins DDB1 and TAK1 in this activity of Vpr. TNF secreted by HIV-1-infected cells triggers NF-κB activity in bystander cells and allows viral reactivation in a model of latently infected cells. Thus, the stimulation of the proinflammatory pathway by Vpr may impact HIV-1 replication in vivo. IMPORTANCE The role of the HIV-1 accessory protein Vpr remains only partially characterized. This protein is important for viral pathogenesis in infected individuals but is dispensable for viral replication in most cell culture systems. Some of the functions described for Vpr remain controversial. In particular, it remains unclear whether Vpr promotes or instead prevents proinflammatory and antiviral immune responses. In this report, we show that Vpr promotes the release of TNF, a proinflammatory cytokine associated with rapid disease progression. Using Vpr mutants or inhibiting selected cellular genes, we show that the cellular proteins DDB1 and TAK1 are involved in the release of TNF by HIV-infected cells. This report provides novel insights into how Vpr manipulates TNF production and helps clarify the role of Vpr in innate immune responses and inflammation

  18. Enhanced Th17 phenotype in uninfected neonates born from viremic HIV-1-infected pregnant women.

    PubMed

    Hygino, Joana; Vieira, Morgana M; Guillermo, Landi V; Silva-Filho, Renato G; Saramago, Carmen; Lima-Silva, Agostinho A; Andrade, Regis M; Andrade, Arnaldao F B; Brindeiro, Rodrigo M; Tanuri, Amilcar; Guimarães, Vander; de Melo Bento, Cleonice Alves

    2011-04-01

    Our objective was to evaluate the in vitro functional profile of T cells from uninfected neonates born from HIV-1-infected pregnant women who controlled (G1) or not (G2) the virus replication. We demonstrated that the lymphoproliferation of T cell to polyclonal activators was higher in the G2 as compared with G1. Nevertheless, no detectable proliferative response was observed in response to HIV-1 antigens in both neonate groups. Cytokine dosage in the supernatants of these polyclonally activated T cell cultures demonstrated that, while IL-10 was the dominant cytokine produced in G1, Th17-related cytokines were significantly higher in G2 neonates. The higher Th17 phenotype tendency in G2 was related to high production of IL-23 by lipopolysaccharide-activated monocyte-derived dendritic cells from these neonates. Our results demonstrated immunological disorders in uninfected neonates born from viremic HIV-1-infected mothers that can help to explain why some of these children have elevated risk of clinical morbidity and mortality due to pathological hypersensitivity.

  19. Enhanced CD4+ cellular apoptosis by CCR5-restricted HIV-1 envelope glycoprotein variants from patients with progressive HIV-1 infection

    SciTech Connect

    Wade, Jessica; Sterjovski, Jasminka; Gray, Lachlan; Roche, Michael; Chiavaroli, Lisa; Ellett, Anne; Jakobsen, Martin R.; Cowley, Daniel; Fonseca Pereira, Candida da; Saksena, Nitin; Wang, Bin; Purcell, Damian F.J.; Karlsson, Ingrid; Fenyoe, Eva-Maria; Churchill, Melissa; Gorry, Paul R.

    2010-01-20

    CCR5-using (R5) human immunodeficiency virus type 1 (HIV-1) strains cause CD4+ T-cell loss in most infected individuals, but mechanisms underlying cytopathicity of R5 viruses are poorly understood. We investigated mechanisms contributing to R5 envelope glycoprotein (Env)-mediated cellular apoptosis by constructing a panel of retroviral vectors engineered to co-express GFP and R5 Envs derived from two HIV-1-infected subjects spanning asymptomatic (Early, E-R5 Envs) to late stages of infection (Late, L-R5 Envs). The L-R5 Envs induced significantly more cellular apoptosis than E-R5 Envs, but only in Env-expressing (GFP-positive) cells, and only in cells where CD4 and CCR5 levels were limiting. Studies with fusion-defective Env mutants showed induction of apoptosis required membrane-fusing events. Our results provide evidence for an intracellular mechanism of R5 Env-induced apoptosis of CD4+ cells that requires membrane fusion. Furthermore, they contribute to a better understanding of mechanisms involved in CD4+ T-cell loss in subjects experiencing progressive R5 HIV-1 infection.

  20. The Microvesicle Component of HIV-1 Inocula Modulates Dendritic Cell Infection and Maturation and Enhances Adhesion to and Activation of T Lymphocytes

    PubMed Central

    Mercier, Sarah K.; Donaghy, Heather; Botting, Rachel A.; Turville, Stuart G.; Harman, Andrew N.; Nasr, Najla; Ji, Hong; Kusebauch, Ulrike; Mendoza, Luis; Shteynberg, David; Sandgren, Kerrie; Simpson, Richard J.; Moritz, Robert L.; Cunningham, Anthony L.

    2013-01-01

    HIV-1 is taken up by immature monocyte derived dendritic cells (iMDDCs) into tetraspanin rich caves from which the virus can either be transferred to T lymphocytes or enter into endosomes resulting in degradation. HIV-1 binding and fusion with the DC membrane results in low level de novo infection that can also be transferred to T lymphocytes at a later stage. We have previously reported that HIV-1 can induce partial maturation of iMDDCs at both stages of trafficking. Here we show that CD45+ microvesicles (MV) which contaminate purified HIV-1 inocula due to similar size and density, affect DC maturation, de novo HIV-1 infection and transfer to T lymphocytes. Comparing iMDDCs infected with CD45-depleted HIV-1BaL or matched non-depleted preparations, the presence of CD45+ MVs was shown to enhance DC maturation and ICAM-1 (CD54) expression, which is involved in DC∶T lymphocyte interactions, while restricting HIV-1 infection of MDDCs. Furthermore, in the DC culture HIV-1 infected (p24+) MDDCs were more mature than bystander cells. Depletion of MVs from the HIV-1 inoculum markedly inhibited DC∶T lymphocyte clustering and the induction of alloproliferation as well as limiting HIV-1 transfer from DCs to T lymphocytes. The effects of MV depletion on these functions were reversed by the re-addition of purified MVs from activated but not non-activated SUPT1.CCR5-CL.30 or primary T cells. Analysis of the protein complement of these MVs and of these HIV-1 inocula before and after MV depletion showed that Heat Shock Proteins (HSPs) and nef were the likely DC maturation candidates. Recombinant HSP90α and β and nef all induced DC maturation and ICAM-1 expression, greater when combined. These results suggest that MVs contaminating HIV-1 released from infected T lymphocytes may be biologically important, especially in enhancing T cell activation, during uptake by DCs in vitro and in vivo, particularly as MVs have been detected in the circulation of HIV-1 infected subjects

  1. ADS-J1 inhibits semen-derived amyloid fibril formation and blocks fibril-mediated enhancement of HIV-1 infection.

    PubMed

    Xun, Tianrong; Li, Wenjuan; Chen, Jinquan; Yu, Fei; Xu, Wei; Wang, Qian; Yu, Ruizhe; Li, Xiaojuan; Zhou, Xuefeng; Lu, Lu; Jiang, Shibo; Li, Lin; Tan, Suiyi; Liu, Shuwen

    2015-09-01

    Semen-derived enhancer of viral infection (SEVI) is composed of amyloid fibrils that can greatly enhance HIV-1 infectivity. By its cationic property, SEVI promotes viral sexual transmission by facilitating the attachment and internalization of HIV-1 to target cells. Therefore, semen-derived amyloid fibrils are potential targets for microbicide design. ADS-J1 is an anionic HIV-1 entry inhibitor. In this study, we explored an additional function of ADS-J1: inhibition of SEVI fibril formation and blockage of SEVI-mediated enhancement of viral infection. We found that ADS-J1 bound to an amyloidogenic peptide fragment (PAP248-286, comprising amino acids 248 to 286 of the enzyme prostatic acid phosphatase), thereby inhibiting peptide assembly into amyloid fibrils. In addition, ADS-J1 binds to mature amyloid fibrils and antagonizes fibril-mediated enhancement of viral infection. Unlike cellulose sulfate, a polyanion that failed in clinical trial to prevent HIV-1 sexual transmission, ADS-J1 shows no ability to facilitate fibril formation. More importantly, the combination of ADS-J1 with several antiretroviral drugs exhibited synergistic effects against HIV-1 infection in semen, with little cytotoxicity to vaginal epithelial cells. Our results suggest that ADS-J1 or a derivative may be incorporated into a combination microbicide for prevention of the sexual transmission of HIV-1.

  2. Neisseria gonorrhoeae enhances HIV-1 infection of primary resting CD4+ T cells through TLR2 activation.

    PubMed

    Ding, Jian; Rapista, Aprille; Teleshova, Natalia; Mosoyan, Goar; Jarvis, Gary A; Klotman, Mary E; Chang, Theresa L

    2010-03-15

    Sexually transmitted infections increase the likelihood of HIV-1 transmission. We investigated the effect of Neisseria gonorrheae (gonococcus [GC]) exposure on HIV replication in primary resting CD4(+) T cells, a major HIV target cell during the early stage of sexual transmission of HIV. GC and TLR2 agonists, such as peptidylglycan (PGN), Pam(3)CSK(4), and Pam(3)C-Lip, a GC-derived synthetic lipopeptide, but not TLR4 agonists including LPS or GC lipooligosaccharide enhanced HIV-1 infection of primary resting CD4(+) T cells after viral entry. Pretreatment of CD4(+) cells with PGN also promoted HIV infection. Anti-TLR2 Abs abolished the HIV enhancing effect of GC and Pam(3)C-Lip, indicating that GC-mediated enhancement of HIV infection of resting CD4(+) T cells was through TLR2. IL-2 was required for TLR2-mediated HIV enhancement. PGN and GC induced cell surface expression of T cell activation markers and HIV coreceptors, CCR5 and CXCR4. The maximal postentry HIV enhancing effect was achieved when PGN was added immediately after viral exposure. Kinetic studies and analysis of HIV DNA products indicated that GC exposure and TLR2 activation enhanced HIV infection at the step of nuclear import. We conclude that GC enhanced HIV infection of primary resting CD4(+) T cells through TLR2 activation, which both increased the susceptibility of primary CD4(+) T cells to HIV infection as well as enhanced HIV-infected CD4(+) T cells at the early stage of HIV life cycle after entry. This study provides a molecular mechanism by which nonulcerative sexually transmitted infections mediate enhancement of HIV infection and has implication for HIV prevention and therapeutics. PMID:20147631

  3. Complement opsonization of HIV-1 results in a different intracellular processing pattern and enhanced MHC class I presentation by dendritic cells

    PubMed Central

    Tjomsland, Veronica; Ellegård, Rada; Burgener, Adam; Mogk, Kenzie; Che, Karlhans F; Westmacott, Garrett; Hinkula, Jorma; Lifson, Jeffrey D; Larsson, Marie

    2013-01-01

    Induction of optimal HIV-1-specific T-cell responses, which can contribute to controlling viral infection in vivo, depends on antigen processing and presentation processes occurring in DCs. Opsonization can influence the routing of antigen processing and pathways used for presentation. We studied antigen proteolysis and the role of endocytic receptors in MHC class I (MHCI) and II (MHCII) presentation of antigens derived from HIV-1 in human monocyte-derived immature DCs (IDCs) and mature DCs, comparing free and complement opsonized HIV-1 particles. Opsonization of virions promoted MHCI presentation by DCs, indicating that complement opsonization routes more virions toward the MHCI presentation pathway. Blockade of macrophage mannose receptor (MMR) and β7-integrin enhanced MHCI and MHCII presentation by IDCs and mature DCs, whereas the block of complement receptor 3 decreased MHCI and MHCII presentation. In addition, we found that IDC and MDC proteolytic activities were modulated by HIV-1 exposure; complement-opsonized HIV-1 induced an increased proteasome activity in IDCs. Taken together, these findings indicate that endocytic receptors such as MMR, complement receptor 3, and β7-integrin can promote or disfavor antigen presentation probably by routing HIV-1 into different endosomal compartments with distinct efficiencies for degradation of viral antigens and MHCI and MHCII presentation, and that HIV-1 affects the antigen-processing machinery. PMID:23526630

  4. 31P NMR conformational studies of non-palindromic DNA duplexes related to HIV-1 enhancer

    NASA Astrophysics Data System (ADS)

    Tisne, C.; Simenel, C.; Hantz, E.; Delepierre, M.

    1998-02-01

    Assignment of all 31P resonances of 16 base-pair DNA duplexes, 5' d(CTGGGGACTTTCCAGG)3' 5' d(CCTGGAAAGTCCCCAG)3', related to the DNA kappaB site of the HIV-1 LTR together with a mutated sequence 5' d(CTGCTCACTTTCCAGG)3' 5' d(CCTGGAAAGTGAGCAG)3' was determined by 2D heteronuclear inverse NMR spectroscopy (HSQC-TOCSY and heteronuclear COSY). ^3JH{3'}-P coupling constants for most of the phosphates of the mutated oligomer were obtained using heteronuclear selective COSY. L'attribution des résonances 31P du fragment d'ADN de seize paires de base 5' d(CTGGGGACTTTCCAGG)3' 5' d(CCTGGAAAGTCCCCAG)3' (16N) correspondant au site kappaB du LTR du HIV-1 et de la séquence mutée 5' d(CTGCTCACTTTCCAGG)3' 5' d(CCTGGAAAGTGAGCAG)3' (16M) a été déterminée à l'aide de méthodes 2D hétéronucléaires à détection indirecte (HSQC-TOCSY et COSY hétéronucléaires). Les constantes de couplage ^3JH{3'}-P ont été mesurées pour la plupart des phosphates de 16 M à l'aide d'expérience COSY hétéronucléaires sélectives.

  5. Complement-mediated, antibody-dependent enhancement of HIV-1 infection in vitro is characterized by increased protein and RNA syntheses and infectious virus release.

    PubMed

    Robinson, W E; Montefiori, D C; Gillespie, D H; Mitchell, W M

    1989-01-01

    Antibody-dependent enhancement (ADE) of human immunodeficiency virus type 1 (HIV-1) infection in vitro has been described recently and was shown to occur by two mechanisms: either participation of the alternative pathway of complement or to involve an Fc receptor-mediated, complement-independent mechanism. Complement-mediated ADE results in an accelerated cytopathic effect in target cells that can abrogate the protective properties of neutralizing antibodies. This study characterizes the surface antigens of MT-2 cells using flow cytometric analysis and shows that these cells express high levels of both CD4 and complement receptor type 2 (CR2) while several CD4+ cell lines that do not demonstrate complement-mediated ADE lack high levels of complement receptors. Further, utilizing MT-2 cell cultures, it is demonstrated that complement-mediated ADE of HIV-1 infection is conferred by the sera from more than 80% of HIV-1 antibody-positive individuals (N = 85). Complement-mediated ADE of HIV-1 infection causes an acceleration of several parameters indicative of HIV-1 infection in vitro including increased HIV-1 antigen synthesis as detected by indirect immunofluorescence, RNA accumulation as measured by a solution hybridization protocol, reverse transcriptase release, and progeny virus production. PMID:2465404

  6. Immune Focusing and Enhanced Neutralization Induced by HIV-1 gp140 Chemical Cross-Linking

    PubMed Central

    Schiffner, T.; Kong, L.; Duncan, C. J. A.; Back, J. W.; Benschop, J. J.; Shen, X.; Huang, P. S.; Stewart-Jones, G. B.; DeStefano, J.; Seaman, M. S.; Tomaras, G. D.; Montefiori, D. C.; Schief, W. R.

    2013-01-01

    Experimental vaccine antigens based upon the HIV-1 envelope glycoproteins (Env) have failed to induce neutralizing antibodies (NAbs) against the majority of circulating viral strains as a result of antibody evasion mechanisms, including amino acid variability and conformational instability. A potential vaccine design strategy is to stabilize Env, thereby focusing antibody responses on constitutively exposed, conserved surfaces, such as the CD4 binding site (CD4bs). Here, we show that a largely trimeric form of soluble Env can be stably cross-linked with glutaraldehyde (GLA) without global modification of antigenicity. Cross-linking largely conserved binding of all potent broadly neutralizing antibodies (bNAbs) tested, including CD4bs-specific VRC01 and HJ16, but reduced binding of several non- or weakly neutralizing antibodies and soluble CD4 (sCD4). Adjuvanted administration of cross-linked or unmodified gp140 to rabbits generated indistinguishable total gp140-specific serum IgG binding titers. However, sera from animals receiving cross-linked gp140 showed significantly increased CD4bs-specific antibody binding compared to animals receiving unmodified gp140. Moreover, peptide mapping of sera from animals receiving cross-linked gp140 revealed increased binding to gp120 C1 and V1V2 regions. Finally, neutralization titers were significantly elevated in sera from animals receiving cross-linked gp140 rather than unmodified gp140. We conclude that cross-linking favors antigen stability, imparts antigenic modifications that selectively refocus antibody specificity and improves induction of NAbs, and might be a useful strategy for future vaccine design. PMID:23843636

  7. Curcumin derivatives as HIV-1 protease inhibitors

    SciTech Connect

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R.

    1993-12-31

    Curcumin, a non-toxic natural compound from Curcuma longa, has been found to be an HIV-1 protease inhibitor. Some of its derivatives were synthesized and their inhibitory activity against the HIV-1 protease was tested. Curcumin analogues containing boron enhanced the inhibitory activity. At least of the the synthesized compounds irreversibly inhibits the HIV-1 protease.

  8. HMBA Enhances Prostratin-Induced Activation of Latent HIV-1 via Suppressing the Expression of Negative Feedback Regulator A20/TNFAIP3 in NF-κB Signaling

    PubMed Central

    Chen, Duchu; Wang, Huiping; Aweya, Jude Juventus; Chen, Yanheng; Chen, Meihua; Wu, Xiaomeng; Chen, Xiaonan; Lu, Jing

    2016-01-01

    In the past decade, much emphasis has been put on the transcriptional activation of HIV-1, which is proposed as a promised strategy for eradicating latent HIV-1 provirus. Two drugs, prostratin and hexamethylene bisacetamide (HMBA), have shown potent effects as inducers for releasing HIV-1 latency when used alone or in combination, although their cellular target(s) are currently not well understood, especially under drug combination. Here, we have shown that HMBA and prostratin synergistically release HIV-1 latency via different mechanisms. While prostratin strongly stimulates HMBA-induced HIV-1 transcription via improved P-TEFb activation, HMBA is capable of boosting NF-κB-dependent transcription initiation by suppressing prostratin-induced expression of the deubiquitinase A20, a negative feedback regulator in the NF-κB signaling pathway. In addition, HMBA was able to increase prostratin-induced phosphorylation and degradation of NF-κB inhibitor IκBα, thereby enhancing and prolonging prostratin-induced nuclear translocation of NF-κB, a prerequisite for stimulation of transcription initiation. Thus, by blocking the negative feedback circuit, HMBA functions as a signaling enhancer of the NF-κB signaling pathway. PMID:27529070

  9. Mycobacterium avium infection in HIV-1-infected subjects increases monokine secretion and is associated with enhanced viral load and diminished immune response to viral antigens.

    PubMed Central

    Denis, M; Ghadirian, E

    1994-01-01

    The complex interaction between HIV-1 infection and Mycobacterium avium was studied. Viral burden was assessed, as well as immune response to HIV-1 in the context of Myco. avium infections. We also examined serum cytokine levels and cytokine release by blood mononuclear cells in HIV-1-infected subjects, infected or not with Myco. avium. Undetectable serum levels of IL-1, tumour necrosis factor-alpha (TNF-alpha) and IL-6 were found in normal controls and in groups I, II and III of HIV-1-infected subjects. Moderate levels of TNF-alpha, IL-1 and IL-6 were found in the sera of group IV patients. When group IV was subdivided into subjects with and without Myco. avium infections, subjects with Myco, avium infections were shown to have higher serum levels of TNF-alpha, IL-1 beta and IL-6 than those with other infections. Blood mononuclear cells from controls and HIV subjects were stimulated with bacterial lipopolysaccharide, and cytokine levels assessed. Cells from group II patients were shown to secrete normal levels of TNF-alpha and IL-6, and lower levels of IL-1 beta; group III subjects released higher levels of IL-6. Patients in group IV had blood cells that released elevated levels of IL-6 and TNF-alpha, and lower levels of IL-1 beta. Group IV subjects with Myco. avium infections had blood cells that released higher levels of TNF-alpha, IL-6 and IL-1 than group IV subjects with other infections. Assessment of viral burden in cells of HIV-1-infected subjects revealed that Myco. avium-infected subjects had a higher level of virus burden and a lower level of lymphoproliferative response to an inactivated gp120-depleted HIV-1 antigen than AIDS subjects with other infections. These data suggest that Myco. avium infections in HIV-1-infected subjects hasten the progression of viral disease, enhance cytokine release and contribute to the anergy to viral antigens. PMID:8033423

  10. Characterization of the Influence of Semen-Derived Enhancer of Virus Infection on the Interaction of HIV-1 with Female Reproductive Tract Tissues

    PubMed Central

    Allen, Shannon A.; Carias, Ann M.; Anderson, Meegan R.; Okocha, Eneniziaogochukwu A.; Benning, Lorie; McRaven, Michael D.; Kelley, Z L.; Lurain, John; Veazey, Ronald S.

    2015-01-01

    ABSTRACT The majority of human immunodeficiency virus type 1 (HIV-1) transmission events occur in women when semen harboring infectious virus is deposited onto the mucosal barriers of the vaginal, ectocervical, and endocervical epithelia. Seminal factors such as semen-derived enhancer of virus infection (SEVI) fibrils were previously shown to greatly enhance the infectivity of HIV-1 in cell culture systems. However, when SEVI is intravaginally applied to living animals, there is no effect on vaginal transmission. To define how SEVI might function in the context of sexual transmission, we applied HIV-1 and SEVI to intact human and rhesus macaque reproductive tract tissues to determine how it influences virus interactions with these barriers. We show that SEVI binds HIV-1 and sequesters most virions to the luminal surface of the stratified squamous epithelium, significantly reducing the number of virions that penetrated the tissue. In the simple columnar epithelium, SEVI was no longer fibrillar in structure and was detached from virions but allowed significantly deeper epithelial virus penetration. These observations reveal that the action of SEVI in intact tissues is very different in the anatomical context of sexual transmission and begin to explain the lack of stimulation of infection observed in the highly relevant mucosal transmission model. IMPORTANCE The most common mode of HIV-1 transmission in women occurs via genital exposure to the semen of HIV-infected men. A productive infection requires the virus to penetrate female reproductive tract epithelial barriers to infect underlying target cells. Certain factors identified within semen, termed semen-derived enhancers of virus infection (SEVI), have been shown to significantly enhance HIV-1 infectivity in cell culture. However, when applied to the genital tracts of living female macaques, SEVI did not enhance virus transmission. Here we show that SEVI functions very differently in the context of intact mucosal

  11. Hyperthermia Stimulates HIV-1 Replication

    PubMed Central

    Roesch, Ferdinand; Meziane, Oussama; Kula, Anna; Nisole, Sébastien; Porrot, Françoise; Anderson, Ian; Mammano, Fabrizio; Fassati, Ariberto; Marcello, Alessandro; Benkirane, Monsef; Schwartz, Olivier

    2012-01-01

    HIV-infected individuals may experience fever episodes. Fever is an elevation of the body temperature accompanied by inflammation. It is usually beneficial for the host through enhancement of immunological defenses. In cultures, transient non-physiological heat shock (42–45°C) and Heat Shock Proteins (HSPs) modulate HIV-1 replication, through poorly defined mechanisms. The effect of physiological hyperthermia (38–40°C) on HIV-1 infection has not been extensively investigated. Here, we show that culturing primary CD4+ T lymphocytes and cell lines at a fever-like temperature (39.5°C) increased the efficiency of HIV-1 replication by 2 to 7 fold. Hyperthermia did not facilitate viral entry nor reverse transcription, but increased Tat transactivation of the LTR viral promoter. Hyperthermia also boosted HIV-1 reactivation in a model of latently-infected cells. By imaging HIV-1 transcription, we further show that Hsp90 co-localized with actively transcribing provirus, and this phenomenon was enhanced at 39.5°C. The Hsp90 inhibitor 17-AAG abrogated the increase of HIV-1 replication in hyperthermic cells. Altogether, our results indicate that fever may directly stimulate HIV-1 replication, in a process involving Hsp90 and facilitation of Tat-mediated LTR activity. PMID:22807676

  12. Enhancing Interferon Regulatory Factor 7 Mediated Antiviral Responses and Decreasing Nuclear Factor Kappa B Expression Limit HIV-1 Replication in Cervical Tissues

    PubMed Central

    Rollenhage, Christiane; Macura, Sherrill L.; Lathrop, Melissa J.; Mackenzie, Todd A.; Doncel, Gustavo F.; Asin, Susana N.

    2015-01-01

    Establishment of a productive HIV-1 infection in the female reproductive tract likely depends on the balance between anti-viral and pro-inflammatory responses leading to activation and proliferation of HIV target cells. Immune modulators that boost anti-viral and depress pro-inflammatory immune responses may decrease HIV-1 infection or replication. Polyinosinic:polycytidylic [Poly (I:C)] has been reported to down-regulate HIV-1 replication in immune cell subsets and lymphoid tissues, yet the scope and mechanisms of poly (I:C) regulation of HIV-1 replication in the cervicovaginal mucosa, the main portal of viral entry in women remain unknown. Using a relevant, underexplored ex vivo cervical tissue model, we demonstrated that poly (I:C) enhanced Interferon Regulatory Factor (IRF)7 mediated antiviral responses and decreased tissue Nuclear Factor Kappa B (NFκB) RNA expression. This pattern of cellular transcription factor expression correlated with decreased HIV-1 transcription and viral release. Reducing IRF7 expression up-regulated HIV-1 and NFκB transcription, providing proof of concept for the critical involvement of IRF7 in cervical tissues. By combining poly (I:C) with a suboptimal concentration of tenofovir, the leading anti-HIV prophylactic microbicide candidate, we demonstrated an earlier and greater decrease in HIV replication in poly (I:C)/tenofovir treated tissues compared with tissues treated with tenofovir alone, indicating overall improved efficacy. Poly (I:C) decreases HIV-1 replication by stimulating IRF7 mediated antiviral responses while reducing NFκB expression. Early during the infection, poly (I:C) improved the anti-HIV-1 activity of suboptimal concentrations of tenofovir likely to be present during periods of poor adherence i.e. inconsistent or inadequate drug use. Understanding interactions between anti-viral and pro-inflammatory immune responses in the genital mucosa will provide crucial insights for the identification of targets that can be

  13. Interleukin-21 administration leads to enhanced antigen-specific T cell responses and natural killer cells in HIV-1 vaccinated mice.

    PubMed

    Ju, Bin; Li, Dan; Ji, Xiaolin; Liu, Jiandong; Peng, Hong; Wang, Shuo; Liu, Ying; Hao, Yanling; Yee, Cassian; Liang, Hua; Shao, Yiming

    2016-05-01

    Interleukin-21 (IL-21), which belongs to IL-2 γ chain receptor cytokine family, is as an important regulator of immune responses. In this study, we developed a novel strategy for immunizing mice with a DNA/vaccinia/protein vaccine in the presence or absence of mouse IL-21 (mIL-21) to evaluate whether mIL-21 could enhance immune responses. Our results demonstrated that co-immunization with mIL-21 did not increase significantly the capacity of vaccine induced antibodies to bind to HIV-1 GP140. An effect of mIL-21 in adjusting the efficacy of HIV-1 vaccine through enhancing Th1 type immune response was however observed. The frequencies of HIV-1-specific cytokine-producing CD4+ T and CD4+ TEM cells, especially multifunctional T cell responses, were significantly increased by co-administrating with mIL-21. A significant increase was also observed in the frequency of NK cells in mIL-21 adjuvant groups. Taken together, combination of mIL-21 with HIV-1 vaccines led to distinct enhancement of NK cells and T cell immune responses associated with immune protection.

  14. Enhanced Sensitivity for Detection of HIV-1 p24 Antigen by a Novel Nuclease-Linked Fluorescence Oligonucleotide Assay

    PubMed Central

    Fan, Peihu; Li, Xiaojun; Su, Weiheng; Kong, Wei; Kong, Xianggui; Wang, Zhenxin; Wang, Youchun; Jiang, Chunlai; Gao, Feng

    2015-01-01

    The relatively high detection limit of the Enzyme-linked immunosorbent assay (ELISA) prevents its application for detection of low concentrations of antigens. To increase the sensitivity for detection of HIV-1 p24 antigen, we developed a highly sensitive nuclease-linked fluorescence oligonucleotide assay (NLFOA). Two major improvements were incorporated in NLFOA to amplify antibody-antigen interaction signals and reduce the signal/noise ratio; a large number of nuclease molecules coupled to the gold nanoparticle/streptavidin complex and fluorescent signals generated from fluorescent-labeled oligonucleotides by the nuclease. The detection limit of p24 by NLFOA was 1 pg/mL, which was 10-fold more sensitive than the conventional ELISA (10 pg/mL). The specificity was 100% and the coefficient of variation (CV) was 7.8% at low p24 concentration (1.5 pg/mL) with various concentrations of spiked p24 in HIV-1 negative sera. Thus, NLFOA is highly sensitive, specific, reproducible and user-friendly. The more sensitive detection of low p24 concentrations in HIV-1-infected individuals by NLFOA could allow detection of HIV-1 infections that are missed by the conventional ELISA at the window period during acute infection to further reduce the risk for HIV-1 infection due to the undetected HIV-1 in the blood products. Moreover, NLFOA can be easily applied to more sensitive detection of other antigens. PMID:25915630

  15. Enhanced Sensitivity for Detection of HIV-1 p24 Antigen by a Novel Nuclease-Linked Fluorescence Oligonucleotide Assay.

    PubMed

    Fan, Peihu; Li, Xiaojun; Su, Weiheng; Kong, Wei; Kong, Xianggui; Wang, Zhenxin; Wang, Youchun; Jiang, Chunlai; Gao, Feng

    2015-01-01

    The relatively high detection limit of the Enzyme-linked immunosorbent assay (ELISA) prevents its application for detection of low concentrations of antigens. To increase the sensitivity for detection of HIV-1 p24 antigen, we developed a highly sensitive nuclease-linked fluorescence oligonucleotide assay (NLFOA). Two major improvements were incorporated in NLFOA to amplify antibody-antigen interaction signals and reduce the signal/noise ratio; a large number of nuclease molecules coupled to the gold nanoparticle/streptavidin complex and fluorescent signals generated from fluorescent-labeled oligonucleotides by the nuclease. The detection limit of p24 by NLFOA was 1 pg/mL, which was 10-fold more sensitive than the conventional ELISA (10 pg/mL). The specificity was 100% and the coefficient of variation (CV) was 7.8% at low p24 concentration (1.5 pg/mL) with various concentrations of spiked p24 in HIV-1 negative sera. Thus, NLFOA is highly sensitive, specific, reproducible and user-friendly. The more sensitive detection of low p24 concentrations in HIV-1-infected individuals by NLFOA could allow detection of HIV-1 infections that are missed by the conventional ELISA at the window period during acute infection to further reduce the risk for HIV-1 infection due to the undetected HIV-1 in the blood products. Moreover, NLFOA can be easily applied to more sensitive detection of other antigens. PMID:25915630

  16. Enhanced Sensitivity for Detection of HIV-1 p24 Antigen by a Novel Nuclease-Linked Fluorescence Oligonucleotide Assay.

    PubMed

    Fan, Peihu; Li, Xiaojun; Su, Weiheng; Kong, Wei; Kong, Xianggui; Wang, Zhenxin; Wang, Youchun; Jiang, Chunlai; Gao, Feng

    2015-01-01

    The relatively high detection limit of the Enzyme-linked immunosorbent assay (ELISA) prevents its application for detection of low concentrations of antigens. To increase the sensitivity for detection of HIV-1 p24 antigen, we developed a highly sensitive nuclease-linked fluorescence oligonucleotide assay (NLFOA). Two major improvements were incorporated in NLFOA to amplify antibody-antigen interaction signals and reduce the signal/noise ratio; a large number of nuclease molecules coupled to the gold nanoparticle/streptavidin complex and fluorescent signals generated from fluorescent-labeled oligonucleotides by the nuclease. The detection limit of p24 by NLFOA was 1 pg/mL, which was 10-fold more sensitive than the conventional ELISA (10 pg/mL). The specificity was 100% and the coefficient of variation (CV) was 7.8% at low p24 concentration (1.5 pg/mL) with various concentrations of spiked p24 in HIV-1 negative sera. Thus, NLFOA is highly sensitive, specific, reproducible and user-friendly. The more sensitive detection of low p24 concentrations in HIV-1-infected individuals by NLFOA could allow detection of HIV-1 infections that are missed by the conventional ELISA at the window period during acute infection to further reduce the risk for HIV-1 infection due to the undetected HIV-1 in the blood products. Moreover, NLFOA can be easily applied to more sensitive detection of other antigens.

  17. Roflumilast enhances the renal protective effects of retinoids in an HIV-1 transgenic mouse model of rapidly progressive renal failure

    PubMed Central

    Zhong, Yifei; Wu, Yingwei; Liu, Ruijie; Deng, Yueyi; Mallipattu, Sandeep; Klotman, Paul; Chuang, Peter; He, John Cijiang

    2011-01-01

    Retinoic acid decreases proteinuria and glomerulosclerosis in several animal models of kidney disease by protecting podocytes from injury. Our recent in vitro studies suggest that all-trans retinoic acid induces podocyte differentiation by activating the retinoic acid receptor-α (RARα)/cAMP/PKA/CREB pathway. When used in combination with all-trans retinoic acid, an inhibitor of phosphodiesterase 4 further enhanced podocyte differentiation by increasing intracellular cAMP. Additionally, we found that Am580, a specific RARα agonist, has similar renal protective effects as all-trans retinoic acid in a rederived colony of HIV-1 transgenic mice with rapidly progressive renal failure (HIV-Tg) that mimics human HIV-associated nephropathy. Treatment with either the inhibitor of phoshodiesterase 4, roflumilast, or Am580 significantly reduced proteinuria, attenuated kidney injury, and improved podocyte differentiation in these HIV-Tg mice. Additional renal protective effects were found when roflumilast was combined with Am580. Consistent with the in vitro data, glomeruli from HIV-Tg mice treated with both Am580 and roflumilast had more active phosphorylated CREB than with either agent alone. Thus, phosphodiesterase 4 inhibitors could be used in combination with RARα agonists to provide additional renal protection. PMID:22258322

  18. Roflumilast enhances the renal protective effects of retinoids in an HIV-1 transgenic mouse model of rapidly progressive renal failure.

    PubMed

    Zhong, Yifei; Wu, Yingwei; Liu, Ruijie; Deng, Yueyi; Mallipattu, Sandeep K; Klotman, Paul E; Chuang, Peter Y; He, John C

    2012-05-01

    Retinoic acid decreases proteinuria and glomerulosclerosis in several animal models of kidney disease by protecting podocytes from injury. Our recent in vitro studies suggest that all-trans retinoic acid induces podocyte differentiation by activating the retinoic acid receptor-α (RARα)/cAMP/PKA/CREB pathway. When used in combination with all-trans retinoic acid, an inhibitor of phosphodiesterase 4 further enhanced podocyte differentiation by increasing intracellular cAMP. Additionally, we found that Am580, a specific RARα agonist, has similar renal protective effects as all-trans retinoic acid in a rederived colony of HIV-1 transgenic mice with rapidly progressive renal failure (HIV-Tg) that mimics human HIV-associated nephropathy. Treatment with either the inhibitor of phosphodiesterase 4, roflumilast, or Am580 significantly reduced proteinuria, attenuated kidney injury, and improved podocyte differentiation in these HIV-Tg mice. Additional renal protective effects were found when roflumilast was combined with Am580. Consistent with the in vitro data, glomeruli from HIV-Tg mice treated with both Am580 and roflumilast had more active phosphorylated CREB than with either agent alone. Thus, phosphodiesterase 4 inhibitors could be used in combination with RARα agonists to provide additional renal protection.

  19. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    SciTech Connect

    Chen, Weizao; Feng, Yang; Wang, Yanping; Zhu, Zhongyu; Dimitrov, Dimiter S.

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  20. Second generation bisheteroarylpiperazine (BHAP) HIV-1 reverse transcriptasae inhibitors: Enhancement of antiviral activity and aqueous solubility via 5- and 6-substitution of the indole ring

    SciTech Connect

    Poel, T.; Thomas, R.C.; Romero, D.L.; Hosley, M.J.; Morge, R.A.; Biles, C.; Reusser, F.; Althaus, I.W.; Schinzer, W.C.; Platzer, D.J.

    1993-12-31

    U-87201E, a potent HIV-1 reverse transcriptase inhibitor (RTI) discovered at Upjohn, is currently in Phase II clinical trials. Additional structure-activity studies have identified second-generation BHAPs with enhanced antiviral activity and improved pharmaceutical properties, notably increased aqueous solubility. Capitalizing on initial SAR studies which demonstrated a tolerance for substitution in the indole ring, a series of BHAPs bearing 5- and 6-substituted indoles was evaluated. Substituents such as ethers, sulfonamides, ureas, and sulfamides containing water-solubilizing groups such as polyethers or basic amines provided highly potent BHAPs with greatly enhanced solubility, such as U-93923. The synthesis, antiviral evaluation and solubility properties of these potent HIV-1 RTIs will be detailed.

  1. Recombination Enhances HIV-1 Envelope Diversity by Facilitating the Survival of Latent Genomic Fragments in the Plasma Virus Population.

    PubMed

    Immonen, Taina T; Conway, Jessica M; Romero-Severson, Ethan O; Perelson, Alan S; Leitner, Thomas

    2015-12-01

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  2. Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

    SciTech Connect

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas; Kouyos, Roger Dimitri

    2015-12-22

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation process including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different fitness

  3. ATP1B3 Protein Modulates the Restriction of HIV-1 Production and Nuclear Factor κ Light Chain Enhancer of Activated B Cells (NF-κB) Activation by BST-2.

    PubMed

    Nishitsuji, Hironori; Sugiyama, Ryuichi; Abe, Makoto; Takaku, Hiroshi

    2016-02-26

    Here, we identify ATP1B3 and fibrillin-1 as novel BST-2-binding proteins. ATP1B3 depletion in HeLa cells (BST-2-positive cells), but not 293T cells (BST-2-negative cells), induced the restriction of HIV-1 production in a BST-2-dependent manner. In contrast, fibrillin-1 knockdown reduced HIV-1 production in 293T and HeLa cells in a BST-2-independent manner. Moreover, NF-κB activation was enhanced by siATP1B3 treatment in HIV-1- and HIV-1ΔVpu-infected HeLa cells. In addition, ATP1B3 silencing induced high level BST-2 expression on the surface of HeLa cells. These results indicate that ATP1B3 is a co-factor that accelerates BST-2 degradation and reduces BST-2-mediated restriction of HIV-1 production and NF-κB activation.

  4. Recombination enhances HIV-1 envelope diversity by facilitating the survival of latent genomic fragments in the plasma virus population

    DOE PAGESBeta

    Immonen, Taina T.; Conway, Jessica M.; Romero-Severson, Ethan O.; Perelson, Alan S.; Leitner, Thomas; Kouyos, Roger Dimitri

    2015-12-22

    HIV-1 is subject to immune pressure exerted by the host, giving variants that escape the immune response an advantage. Virus released from activated latent cells competes against variants that have continually evolved and adapted to host immune pressure. Nevertheless, there is increasing evidence that virus displaying a signal of latency survives in patient plasma despite having reduced fitness due to long-term immune memory. We investigated the survival of virus with latent envelope genomic fragments by simulating within-host HIV-1 sequence evolution and the cycling of viral lineages in and out of the latent reservoir. Our model incorporates a detailed mutation processmore » including nucleotide substitution, recombination, latent reservoir dynamics, diversifying selection pressure driven by the immune response, and purifying selection pressure asserted by deleterious mutations. We evaluated the ability of our model to capture sequence evolution in vivo by comparing our simulated sequences to HIV-1 envelope sequence data from 16 HIV-infected untreated patients. Empirical sequence divergence and diversity measures were qualitatively and quantitatively similar to those of our simulated HIV-1 populations, suggesting that our model invokes realistic trends of HIV-1 genetic evolution. Moreover, reconstructed phylogenies of simulated and patient HIV-1 populations showed similar topological structures. Our simulation results suggest that recombination is a key mechanism facilitating the persistence of virus with latent envelope genomic fragments in the productively infected cell population. Recombination increased the survival probability of latent virus forms approximately 13-fold. Prevalence of virus with latent fragments in productively infected cells was observed in only 2% of simulations when we ignored recombination, while the proportion increased to 27% of simulations when we allowed recombination. We also found that the selection pressures exerted by different

  5. Herpes simplex virus type-2 stimulates HIV-1 replication in cervical tissues: implications for HIV-1 transmission and efficacy of anti-HIV-1 microbicides.

    PubMed

    Rollenhagen, C; Lathrop, M J; Macura, S L; Doncel, G F; Asin, S N

    2014-09-01

    Herpes Simplex virus Type-2 (HSV-2) increases the risk of HIV-1 acquisition, yet the mechanism for this viral pathogen to regulate the susceptibility of the cervicovaginal mucosa to HIV-1 is virtually unknown. Using ex vivo human ectocervical tissue models, we report greater levels of HIV-1 reverse transcription, DNA integration, RNA expression, and virions release in HIV-1/HSV-2 co-infected tissues compared with HIV-1 only infected tissues (P<0.05). Enhanced HIV-1 replication was associated with increased CD4, CCR5, and CD38 transcription (P<0.05) and increased number of CD4(+)/CCR5(+)/CD38(+) T cells in HIV-1/HSV-2 co-infected tissues compared with tissues infected with HIV-1 alone. Tenofovir (TFV) 1% gel, the leading microbicide candidate, demonstrated only partial protection against HIV-1, when applied vaginally before and after sexual intercourse. It is possible that mucosal inflammation, in particular that induced by HSV-2 infection, may have decreased TFV efficacy. HSV-2 upregulated the number of HIV-1-infected cells and elevated the concentration of TFV needed to decrease HIV-1 infection. Similarly, only high concentrations of TFV inhibited HSV-2 replication in HIV-1/HSV-2-infected tissues. Thus, HSV-2 co-infection and mucosal immune cell activation should be taken into consideration when designing preventative strategies for sexual transmission of HIV-1.

  6. Nef-induced alteration of the early/recycling endosomal compartment correlates with enhancement of HIV-1 infectivity.

    PubMed

    Madrid, Ricardo; Janvier, Katy; Hitchin, Douglas; Day, John; Coleman, Scott; Noviello, Colleen; Bouchet, Jerome; Benmerah, Alexandre; Guatelli, John; Benichou, Serge

    2005-02-11

    human immunodeficiency virus type 1 (HIV-1) Nef interacts with the clathrin-associated AP-1 and AP-3 adaptor complexes, stabilizing their association with endosomal membranes. These findings led us to hypothesize a general impact of this viral protein on the endosomal system. Here, we have shown that Nef specifically disturbs the morphology of the early/recycling compartment, inducing a redistribution of early endosomal markers and a shortening of the tubular recycling endosomal structures. Furthermore, Nef modulates the trafficking of the transferrin receptor (TfR), the prototypical recycling surface protein, indicating that it also disturbs the function of this compartment. Nef reduces the rate of recycling of TfR to the plasma membrane, causing TfR to accumulate in early endosomes and reducing its expression at the cell surface. These effects depend on the leucine-based motif of Nef, which is required for the membrane stabilization of AP-1 and AP-3 complexes. Since we show that this motif is also required for the full infectivity of HIV-1 virions, these results indicate that the positive influence of Nef on viral infectivity may be related to its general effects on early/recycling endosomal compartments. PMID:15569681

  7. Psychoneuroimmunology and HIV-1.

    ERIC Educational Resources Information Center

    Antoni, Michael H.; And Others

    1990-01-01

    Presents evidence describing benefits of behavioral interventions such as aerobic exercise training on both psychological and immunological functioning among high risk human immunodeficiency virus-Type 1 (HIV-1) seronegative and very early stage seropositive homosexual men. HIV-1 infection is cast as chronic disease for which early…

  8. HIV-1 gp120 enhances outward potassium current via CXCR4 and cAMP-dependent PKA signaling in cultured rat microglia

    PubMed Central

    Xu, Changshui; Liu, Jianuo; Chen, Lina; Liang, Shangdong; Fujii, Nobutaka; Tamamura, Hirokazu; Xiong, Huangui

    2011-01-01

    Microglia are critical cells in mediating the pathophysiology of neurodegenerative disorders such as HIV-associated neurocognitive disorders. We hypothesize that HIV-1 glycoprotein 120 (gp120) activates microglia by enhancing outward K+ currents, resulting in microglia secretion of neurotoxins and consequent neuronal dysfunction and death. To test this hypothesis, we studied the effects of gp120 on outward K+ current in cultured rat microglia. Application of gp120 enhanced outward K+ current in a dose-dependent manner, which was blocked by voltage-gated K+ (Kv) channel blockers. Western blot analysis revealed that gp120 produced an elevated expression of Kv channel proteins. Examination of activation and inactivation of outward K+ currents showed that gp120 shifted membrane potentials for activation and steady-state inactivation. The gp120-associated enhancement of outward K+ current was blocked by a CXCR4 receptor antagonist T140 or by a specific protein kinase A (PKA) inhibitor H89, suggesting the involvement of chemokine receptor CXCR4 and PKA in gp120-mediated enhancement of outward K+ current. Biological significance of gp120-induced enhancement of microglia outward K+ current was demonstrated by experimental results showing the neurotoxic activity of gp120-stimulated microglia, evaluated by TUNEL staining and MTT assay, was significantly attenuated by Kv channel blockers. Taken together, these results suggest that gp120 induces microglia neurotoxic activity by enhancing microglia outward K+ current and that microglia Kv channels may function as a potential target for the development of therapeutic strategies. PMID:21438014

  9. Suppression of HIV-1 Infectivity by Human Glioma Cells.

    PubMed

    Hoque, Sheikh Ariful; Tanaka, Atsushi; Islam, Salequl; Ahsan, Gias Uddin; Jinno-Oue, Atsushi; Hoshino, Hiroo

    2016-05-01

    HIV-1 infection to the central nervous system (CNS) is very common in AIDS patients. The predominant cell types infected in the brain are monocytes and macrophages, which are surrounded by several HIV-1-resistant cell types, such as astrocytes, oligodendrocytes, neurons, and microvascular cells. The effect of these HIV-1-resistant cells on HIV-1 infection is largely unknown. In this study, we examined the stability of HIV-1 cultured with several human glioblastoma cell lines, for example, NP-2, U87MG, T98G, and A172, to determine whether these HIV-1-resistant brain cells could enhance or suppress HIV-1 infection and thus modulate HIV-1 infection in the CNS. The HIV-1 titer was determined using the MAGIC-5A indicator cell line as well as naturally occurring CD4(+) T cells. We found that the stability of HIV-1 incubated with NP-2 or U87MG cells at 37°C was significantly shorter (half-life, 2.5-4 h) compared to that of HIV-1 incubated with T98G or A172 cells or in culture medium without cells (half-life, 8-18 h). The spent culture media (SCM) of NP-2 and U87MG cells had the ability to suppress both R5- and X4-HIV-1 infection by inhibiting HIV-1 attachment to target cells. This inhibitory effect was eliminated by the treatment of the SCM with chondroitinase ABC but not heparinase, suggesting that the inhibitory factor(s) secreted by NP-2 and U87MG cells was chiefly mediated by chondroitin sulfate (CS) or CS-like moiety. Thus, this study reveals that some but not all glioma cells secrete inhibitory molecules to HIV-1 infection that may contribute in lowering HIV-1 infection in the CNS in vivo. PMID:26650729

  10. Suppression of HIV-1 Infectivity by Human Glioma Cells.

    PubMed

    Hoque, Sheikh Ariful; Tanaka, Atsushi; Islam, Salequl; Ahsan, Gias Uddin; Jinno-Oue, Atsushi; Hoshino, Hiroo

    2016-05-01

    HIV-1 infection to the central nervous system (CNS) is very common in AIDS patients. The predominant cell types infected in the brain are monocytes and macrophages, which are surrounded by several HIV-1-resistant cell types, such as astrocytes, oligodendrocytes, neurons, and microvascular cells. The effect of these HIV-1-resistant cells on HIV-1 infection is largely unknown. In this study, we examined the stability of HIV-1 cultured with several human glioblastoma cell lines, for example, NP-2, U87MG, T98G, and A172, to determine whether these HIV-1-resistant brain cells could enhance or suppress HIV-1 infection and thus modulate HIV-1 infection in the CNS. The HIV-1 titer was determined using the MAGIC-5A indicator cell line as well as naturally occurring CD4(+) T cells. We found that the stability of HIV-1 incubated with NP-2 or U87MG cells at 37°C was significantly shorter (half-life, 2.5-4 h) compared to that of HIV-1 incubated with T98G or A172 cells or in culture medium without cells (half-life, 8-18 h). The spent culture media (SCM) of NP-2 and U87MG cells had the ability to suppress both R5- and X4-HIV-1 infection by inhibiting HIV-1 attachment to target cells. This inhibitory effect was eliminated by the treatment of the SCM with chondroitinase ABC but not heparinase, suggesting that the inhibitory factor(s) secreted by NP-2 and U87MG cells was chiefly mediated by chondroitin sulfate (CS) or CS-like moiety. Thus, this study reveals that some but not all glioma cells secrete inhibitory molecules to HIV-1 infection that may contribute in lowering HIV-1 infection in the CNS in vivo.

  11. Raman spectroscopy of HIV-1 antigen and antibody

    NASA Astrophysics Data System (ADS)

    Zinin, Pavel V.; Hu, Ningjie; Kamemoto, Lori E.; Yu, Qigui; Misra, Anupam K.; Sharma, Shiv K.

    2011-05-01

    Raman spectra of anti-HIV-1 antibody, HIV-1 antigen (p24), and HIV-1 antibody-antigen complex have been measured in near-infrared and UV regions: 785 nm; 830 nm; and 244 nm laser excitations. The spectrum of the HIV-1 antigen was excited with an infrared laser and contains numerous Raman peaks. The most prominent peaks are broad bands at 1343, 1449, 1609 and 1655 cm-1, which are characteristic of the Raman spectra of biological cells. The UV Raman spectrum of the HIV-1 antigen has a completely different structure. It has two strong peaks at 1613 cm-1 and 1173 cm-1. The peak at 1613 cm-1 is associated with vibrations of the aromatic amino acids tyrosine (Tyr) and tryptophan (Try). The second strongest peak at 1173 cm-1 is associated with the vibration of Tyr. The Raman peak pattern of the HIV-1 antigen-antibody complex is very similar to that of the HIV-1 antigen. The only difference is that the peak at 1007 cm-1 of the Raman spectrum of the HIV-1 antigen-antibody complex is slightly enhanced compared to that of the HIV-1 antigen. This indicates that the peaks of the HIV-1 antigen dominate the Raman spectrum of the HIV-1 antigen-antibody complex.

  12. Combination genetic therapy to inhibit HIV-1.

    PubMed

    Strayer, David S; Branco, Francisco; Landré, Julien; BouHamdan, Mohamad; Shaheen, Farida; Pomerantz, Roger J

    2002-01-01

    Compared with single agents, combination antilentiviral pharmacotherapy targets multiple HIV-1 functions simultaneously, maximizing efficacy and decreasing chances of escape mutations. Combination genetic therapy could theoretically enhance efficacy similarly, but delivery of even single genes to high percentages of hematopoietic cells or their derivatives has proven problematic. Because of their high efficiency of gene delivery, we tested recombinant SV40-derived vectors (rSV40s) for this purpose. We made six rSV40s, each carrying a different transgene that targeted a different lentiviral function. We tested the ability of these constructs, individually and in double and triple combinations, to protect SupT1 human T lymphoma cells from HIV-1 challenge. Single chain antibodies (SFv) against CXCR4 and against HIV-1 reverse transcriptase (RT) and integrase (IN) were used, as were polymeric TAR decoys (PolyTAR) and a dominant-negative mutant of HIV-1 Rev (RevM10). Immunostaining showed that virtually all doubly treated cells expressed both transgenes. All transgenes individually protected from HIV-1 but, except for anti-CXCR4 SFv, their effectiveness diminished as challenge doses increased from 40 through 2500 tissue culture infectious dose(50) (TCID(50))/10(6) cells. However, all combinations of transgenes protected target cells better than individual transgenes, even from the highest challenge doses. Thus, combination gene therapies may inhibit HIV-1 better than single agents, and rSV40s may facilitate delivery of multigene therapeutics.

  13. N-Methylation as a Strategy for Enhancing the Affinity and Selectivity of RNA-binding Peptides: Application to the HIV-1 Frameshift-Stimulating RNA.

    PubMed

    Hilimire, Thomas A; Bennett, Ryan P; Stewart, Ryan A; Garcia-Miranda, Pablo; Blume, Alex; Becker, Jordan; Sherer, Nathan; Helms, Eric D; Butcher, Samuel E; Smith, Harold C; Miller, Benjamin L

    2016-01-15

    Human Immunodeficiency Virus (HIV) type 1 uses a -1 programmed ribosomal frameshift (-1 PRF) event to translate its enzymes from the same transcript used to encode the virus' structural proteins. The frequency of this event is highly regulated, and significant deviation from the normal 5-10% frequency has been demonstrated to decrease viral infectivity. Frameshifting is primarily regulated by the Frameshift Stimulatory Signal RNA (FSS-RNA), a thermodynamically stable, highly conserved stem loop that has been proposed as a therapeutic target. We describe the design, synthesis, and testing of a series of N-methyl peptides able to bind the HIV-1 FSS RNA stem loop with low nanomolar affinity and high selectivity. Surface plasmon resonance (SPR) data indicates increased affinity is a reflection of a substantially enhanced on rate. Compounds readily penetrate cell membranes and inhibit HIV infectivity in a pseudotyped virus assay. Viral infectivity inhibition correlates with compound-dependent changes in the ratios of Gag and Gag-Pol in virus particles. As the first compounds with both single digit nanomolar affinities for the FSS RNA and an ability to inhibit HIV in cells, these studies support the use of N-methylation for enhancing the affinity, selectivity, and bioactivity of RNA-binding peptides. PMID:26496521

  14. N-Methylation as a Strategy for Enhancing the Affinity and Selectivity of RNA-binding Peptides: Application to the HIV-1 Frameshift-Stimulating RNA

    PubMed Central

    2015-01-01

    Human Immunodeficiency Virus (HIV) type 1 uses a −1 programmed ribosomal frameshift (−1 PRF) event to translate its enzymes from the same transcript used to encode the virus’ structural proteins. The frequency of this event is highly regulated, and significant deviation from the normal 5–10% frequency has been demonstrated to decrease viral infectivity. Frameshifting is primarily regulated by the Frameshift Stimulatory Signal RNA (FSS-RNA), a thermodynamically stable, highly conserved stem loop that has been proposed as a therapeutic target. We describe the design, synthesis, and testing of a series of N-methyl peptides able to bind the HIV-1 FSS RNA stem loop with low nanomolar affinity and high selectivity. Surface plasmon resonance (SPR) data indicates increased affinity is a reflection of a substantially enhanced on rate. Compounds readily penetrate cell membranes and inhibit HIV infectivity in a pseudotyped virus assay. Viral infectivity inhibition correlates with compound-dependent changes in the ratios of Gag and Gag-Pol in virus particles. As the first compounds with both single digit nanomolar affinities for the FSS RNA and an ability to inhibit HIV in cells, these studies support the use of N-methylation for enhancing the affinity, selectivity, and bioactivity of RNA-binding peptides. PMID:26496521

  15. Structural Characterization of Semen Coagulum-Derived SEM1(86–107) Amyloid Fibrils That Enhance HIV-1 Infection

    PubMed Central

    2015-01-01

    SEM1(86–107) is a 22-residue peptide corresponding to residues 86–107 in the semenogelin I protein. SEM1(86–107) is an abundant component of freshly liquefied semen and forms amyloid fibrils capable of enhancing HIV infection. To probe the factors affecting fibril formation and gain a better understanding of how differences in pH between semen and vaginal fluid affect fibril stability, this study determined the effect of pH on SEM1(86–107) fibril formation and dissociation. The SEM1(86–107) fibril structure (i.e., residues that comprise the fibrillar core) was also probed using hydrogen–deuterium exchange mass spectrometry (HDXMS) and hydroxyl radical-mediated protein modification. The average percent exposure to hydroxyl radical-mediated modification in the SEM1(86–107) fibrils was determined without requiring tandem mass spectrometry spectral acquisition or complete separation of modified peptides. It was found that the residue exposures calculated from HDXMS and hydroxyl radical-mediated modification were similar. These techniques demonstrated that three regions of SEM1(86–107) comprise the amyloid fibril core and that positively charged residues are exposed, suggesting that electrostatic interactions between SEM1(86–107) and HIV or the cell surface may be responsible for mediating HIV infection enhancement by the SEM1(86–107) fibrils. PMID:24811874

  16. CCAAT Enhancer Binding Protein and Nuclear Factor of Activated T Cells Regulate HIV-1 LTR via a Novel Conserved Downstream Site in Cells of the Monocyte-Macrophage Lineage

    PubMed Central

    Dahiya, Satinder; Liu, Yujie; Nonnemacher, Michael R.; Dampier, Will; Wigdahl, Brian

    2014-01-01

    Transcriptional control of the human immunodeficiency virus type 1 (HIV-1) promoter, the long terminal repeat (LTR), is achieved by interactions with cis-acting elements present both upstream and downstream of the start site. In silico transcription factor binding analysis of the HIV-1 subtype B LTR sequences revealed a potential downstream CCAAT enhancer binding protein (C/EBP) binding site. This binding site (+158 to+172), designated DS3, was found to be conserved in 67% of 3,858 unique subtype B LTR sequences analyzed in terms of nucleotide sequence as well as physical location in the LTR. DS3 was found to be well represented in other subtypes as well. Interestingly, DS3 overlaps with a previously identified region that bind members of the nuclear factor of activated T cells (NFAT) family of proteins. NFATc2 exhibited a higher relative affinity for DS3 as compared with members of the C/EBP family (C/EBP α and β). DS3 was able to compete efficiently with the low-affinity upstream C/EBP binding site I with respect to C/EBP binding, suggesting utilization of both NFAT and C/EBP. Moreover, cyclosporine A treatment, which has been shown to prevent dephosphorylation and nuclear translocation of NFAT isoforms, resulted in enhanced C/EBPα binding. The interactions at DS3 were also validated in an integrated HIV-1 LTR in chronically infected U1 cells. A binding knockout of DS3 demonstrated reduced HIV-1 LTR-directed transcription under both basal and interleukin-6-stimulated conditions only in cells of the monocyte-macrophage lineage cells and not in cells of T-cell origin. Thus, the events at DS3 positively regulate the HIV-1 promoter in cells of the monocyte-macrophage lineage. PMID:24551078

  17. Design of HIV-1 protease inhibitors with pyrrolidinones and oxazolidinones as novel P1'-ligands to enhance backbone-binding interactions with protease: synthesis, biological evaluation, and protein-ligand X-ray studies

    SciTech Connect

    Ghosh, Arun K.; Leshchenko-Yashchuk, Sofiya; Anderson, David D.; Baldridge, Abigail; Noetzel, Marcus; Miller, Heather B.; Tie, Yunfeng; Wang, Yuan-Fang; Koh, Yasuhiro; Weber, Irene T.; Mitsuya, Hiroaki

    2009-09-02

    Structure-based design, synthesis, and biological evaluation of a series of novel HIV-1 protease inhibitors are described. In an effort to enhance interactions with protease backbone atoms, we have incorporated stereochemically defined methyl-2-pyrrolidinone and methyl oxazolidinone as the P1{prime}-ligands. These ligands are designed to interact with Gly-27{prime} carbonyl and Arg-8 side chain in the S1{prime}-subsite of the HIV protease. We have investigated the potential of these ligands in combination with our previously developed bis-tetrahydrofuran (bis-THF) and cyclopentanyltetrahydrofuran (Cp-THF) as the P2-ligands. Inhibitor 19b with a (R)-aminomethyl-2-pyrrolidinone and a Cp-THF was shown to be the most potent compound. This inhibitor maintained near full potency against multi-PI-resistant clinical HIV-1 variants. A high resolution protein-ligand X-ray crystal structure of 19b-bound HIV-1 protease revealed that the P1{prime}-pyrrolidinone heterocycle and the P2-Cp-ligand are involved in several critical interactions with the backbone atoms in the S1{prime} and S2 subsites of HIV-1 protease.

  18. HIV-1 therapy with monoclonal antibody 3BNC117 elicits host immune responses against HIV-1.

    PubMed

    Schoofs, Till; Klein, Florian; Braunschweig, Malte; Kreider, Edward F; Feldmann, Anna; Nogueira, Lilian; Oliveira, Thiago; Lorenzi, Julio C C; Parrish, Erica H; Learn, Gerald H; West, Anthony P; Bjorkman, Pamela J; Schlesinger, Sarah J; Seaman, Michael S; Czartoski, Julie; McElrath, M Juliana; Pfeifer, Nico; Hahn, Beatrice H; Caskey, Marina; Nussenzweig, Michel C

    2016-05-20

    3BNC117 is a broad and potent neutralizing antibody to HIV-1 that targets the CD4 binding site on the viral envelope spike. When administered passively, this antibody can prevent infection in animal models and suppress viremia in HIV-1-infected individuals. Here we report that HIV-1 immunotherapy with a single injection of 3BNC117 affects host antibody responses in viremic individuals. In comparison to untreated controls that showed little change in their neutralizing activity over a 6-month period, 3BNC117 infusion significantly improved neutralizing responses to heterologous tier 2 viruses in nearly all study participants. We conclude that 3BNC117-mediated immunotherapy enhances host humoral immunity to HIV-1. PMID:27199429

  19. Progesterone augments cell susceptibility to HIV-1 and HIV-1/HSV-2 co-infections.

    PubMed

    Ragupathy, Viswanath; Xue, Wang; Tan, Ji; Devadas, Krishnakumar; Gao, Yamei; Hewlett, Indira

    2016-10-01

    In human immunodeficiency virus type 1 (HIV-1)-infected women, oral or injectable progesterone containing contraceptive pills may enhance HIV-1 acquisition in vivo, and the mechanism by which this occurs is not fully understood. In developing countries, Herpes simplex virus type-2 (HSV-2) co-infection has been shown to be a risk for increase of HIV-1 acquisition and, if co-infected women use progesterone pills, infections may increase several fold. In this study, we used an in vitro cell culture system to study the effects of progesterone on HIV-1 replication and to explore the molecular mechanism of progesterone effects on infected cells. In our in vitro model, CEMss cells (lymphoblastoid cell line) were infected with either HIV-1 alone or co-infected with HSV-2. HIV-1 viral load was measured with and without sex hormone treatment. Progesterone-treated cells showed an increase in HIV-1 viral load (1411.2 pg/mL) compared with cells without progesterone treatment (993.1 pg/mL). Increased cell death was noted with HSV-2 co-infection and in progesterone-treated cells. Similar observations were noted in peripheral blood mononuclear cells (PBMC) cells derived from three female donors. Progesterone-treated cells also showed reduced antiviral efficacy. Inflammatory cytokines and associations with biomarkers of disease progression were explored. Progesterone upregulated inflammatory cytokines and chemokines conversely and downregulated anti-apoptotic Bcl-2 expression. Nuclear protein analysis by electrophoretic mobility shift assay showed the association of progesterone with progesterone response element (PRE), which may lead to downregulation of Bcl-2. These data indicate that progesterone treatment enhances HIV-1 replication in infected cells and co-infection with HSV-2 may further fuel this process. PMID:27538988

  20. Brain pericytes increase the lipopolysaccharide-enhanced transcytosis of HIV-1 free virus across the in vitro blood–brain barrier: evidence for cytokine-mediated pericyte-endothelial cell crosstalk

    PubMed Central

    2013-01-01

    Background Human immunodeficiency virus-1 (HIV-1) enters the brain by crossing the blood–brain barrier (BBB) as both free virus and within infected immune cells. Previous work showed that activation of the innate immune system with lipopolysaccharide (LPS) enhances free virus transport both in vivo and across monolayer monocultures of brain microvascular endothelial cells (BMECs) in vitro. Methods Here, we used monocultures and co-cultures of brain pericytes and brain endothelial cells to examine the crosstalk between these cell types in mediating the LPS-enhanced permeation of radioactively-labeled HIV-1 (I-HIV) across BMEC monolayers. Results We found that brain pericytes when co-cultured with BMEC monolayers magnified the LPS-enhanced transport of I-HIV without altering transendothelial electrical resistance, indicating that pericytes affected the transcytotic component of HIV-1 permeation. As LPS crosses the BBB poorly if at all, and since pericytes are on the abluminal side of the BBB, we postulated that luminal LPS acts indirectly on pericytes through abluminal secretions from BMECs. Consistent with this, we found that the pattern of secretion of cytokines by pericytes directly exposed to LPS was different than when the pericytes were exposed to the abluminal fluid from LPS-treated BMEC monolayers. Conclusion These results are evidence for a cellular crosstalk in which LPS acts at the luminal surface of the brain endothelial cell, inducing abluminal secretions that stimulate pericytes to release substances that enhance the permeability of the BMEC monolayer to HIV. PMID:23816186

  1. Early Infection HIV-1 Envelope V1-V2 Genotypes Do Not Enhance Binding or Replication in Cells Expressing High Levels of α4β7 Integrin

    PubMed Central

    Etemad, Behzad; Gonzalez, Oscar A.; McDonough, Sean; Pena-Cruz, Victor; Sagar, Manish

    2013-01-01

    It has been postulated that HIV-1 envelope properties, such as shorter and less glycosylated V1-V2 loops commonly observed among non-subtype B early – transmitted viruses, promote utilization of the gut homing integrin α4β7. This property potentially confers an advantage to some HIV-1 variants early after acquisition. We found that replication competent recombinant viruses incorporating HIV-1 subtype A compact and less glycosylated early versus chronic phase V1-V2 loops demonstrated no significant difference in binding to α4β7 high CD8+ T cells or replication in α4β7 high CD4+ T cells. Integrin α4β7 usage does not select for shorter less glycosylated envelopes during transmission. PMID:23797693

  2. Early infection HIV-1 envelope V1-V2 genotypes do not enhance binding or replication in cells expressing high levels of α4β7 integrin.

    PubMed

    Etemad, Behzad; Gonzalez, Oscar A; McDonough, Sean; Pena-Cruz, Victor; Sagar, Manish

    2013-11-01

    It has been postulated that HIV-1 envelope properties, such as shorter and less-glycosylated V1-V2 loops commonly observed among non-subtype B early-transmitted viruses, promote utilization of the gut homing integrin α4β7. This property potentially confers an advantage to some HIV-1 variants early after acquisition. We found that replication-competent recombinant viruses incorporating HIV-1 subtype A compact and less-glycosylated early versus chronic phase V1-V2 loops demonstrated no significant difference in binding to α4β7 high CD8⁺ T cells or replication in α4β7 high CD4⁺ T cells. Integrin α4β7 usage does not select for shorter less-glycosylated envelopes during transmission. PMID:23797693

  3. Repeated cocaine treatment enhances HIV-1 Tat-induced cortical excitability via over-activation of L-type calcium channels.

    PubMed

    Napier, T Celeste; Chen, Lihua; Kashanchi, Fatah; Hu, Xiu-Ti

    2014-06-01

    The prefrontal cortex (PFC) is dysregulated in neuroAIDS and during cocaine abuse. Repeated cocaine treatment upregulates voltage gated L-type Ca(2+) channels in pyramidal neurons within the rat medial PFC (mPFC). L-type Ca(2+) channels are also upregulated by the HIV-1 neurotoxic protein, Tat, but the role of Tat in pyramidal cell function is unknown. This represents a major knowledge gap as PFC pyramidal neurons are important mediators of behaviors that are disrupted in neuroAIDS and by chronic cocaine exposure. To determine if L-channel-mediated Ca(2+) dysregulation in mPFC pyramidal neurons are a common neuropathogenic site for Tat and chronic cocaine, we evaluated the electrophysiological effects of recombinant Tat on these neurons in forebrain slices taken from rats 1-3 days after five, once-daily treatments of cocaine (15 mg/kg, ip) or saline. In saline-treated rats, bath-applied Tat facilitated membrane depolarization and firing. Ca(2+) influx was increased (indicated by prolonged Ca(2+) spikes) with low concentrations of Tat (10-40nM), but reduced by higher concentrations (80-160nM), the latter likely reflecting dysfunction associated with excessive excitation. Tat-mediated effects were detected during NMDA/AMPA receptor blockade, and abolished by blocking activated L-channels with diltiazem. In neurons from cocaine-treated rats, the Tat-induced effects on evoked firing and Ca(2+) spikes were significantly enhanced above that obtained with Tat in slices from saline-treated rats. Thus, glutamatergic receptor-independent over-activation of L-channels contributed to the Tat-induced hyper-reactivity of mPFC pyramidal neurons to excitatory stimuli, which was exacerbated in rats repeatedly exposed to cocaine. Such effects may contribute to the exaggerated neuropathology reported for HIV(+) cocaine-abusing individuals.

  4. Rapid fluorescent assay for screening drugs on Leishmania amastigotes.

    PubMed

    Shimony, Orly; Jaffe, Charles L

    2008-10-01

    A rapid fluorescent viability assay employing alamarBlue was optimized for use with Leishmania axenic amastigotes, the stage of the parasite responsible for disease pathology. The activity of two protein kinase inhibitors, Staurosporine and H-89, as well as Amphotericin B, on promastigotes and amastigotes of Leishmania donovani and Leishmania tropica was compared. Both protein kinase inhibitors inhibited promastigote growth at lower concentrations than amastigotes, while the GI(50) for Amphotericin B on both stages was similar. This assay only requires a limited number of axenic amastigotes (50,000 cells/well) and can be used to rapidly screen large chemical or natural product libraries for activity against amastigotes.

  5. [Inhibitory effect of human saliva on HIV-1 infectivity].

    PubMed

    Etsuko, K; Wei, S

    2001-08-01

    Human saliva is known to decrease human immunodeficiency virus type 1 (HIV-1) infectivity in vitro. The purpose of this study was to confirm these findings and to explore the mechanism of action of saliva. Whole saliva from seronegative donors was incubated with HIV-1IIIB chronically infected MOLT 4 cells (MOLT 4/HIV-1IIIB cells) or cell-free HIV-1IIIB or KMT strains. We monitored viral infectivity by using MAGI/CCR5 cells. Whole saliva with Na levels less than 20 mEq/l rapidly damaged MOLT 4/HIV-1IIIB cells, thereby HIV infection to MAGI/CCR5 cells by MOLT 4/HIV-1IIIB cells was nearly abolished. On the contrary, in the cace of whole saliva with Na levels more than 23 mEq/l which damaged few cells, cell-to-cell transmission of HIV-1IIIB was prevented by more than 50%. The infectivity of cell-free HIV-1IIIB to MAGI/CCR5 cells was abolished after incubating and filtering the HIV with whole saliva. Depletion of secretory leukocyte protease inhibitor (SLPI) from whole saliva resulted in a 11-28% decrease in the anti HIV-1KMT activity of saliva. Preincubation of host cells with whole saliva led to an enhancement of the HIV infection rather than inhibition. Whole saliva had no effect on the expression level of the cellular receptors (CD4, CXCR4 and CCR5). These results suggest that the inhibitory effect of whole saliva on HIV-1 infectivity is directly linked to the virus itself rather than on the host cell. Moreover, the physical entrapment of cell-free HIV-1 by whole saliva seems to have major salivaly defence mechanisms against HIV-1 infection through the oral cavity. PMID:16578966

  6. Impaired IL-2 expression in latent HIV-1 infection.

    PubMed

    Shin, YoungHyun; Yoon, Cheol-Hee; Lim, Hoyong; Park, Jihwan; Roh, Tae-Young; Kang, Chun; Choi, Byeong-Sun

    2015-08-01

    Regarding the T cell function in HIV-1 infection, activation of T cells is enhanced in acutely HIV-1-infected T cells upon stimuli. However, T cell immune responses underlying the activation of T cell receptor (TCR) signaling molecules and interleukin (IL)-2 production in latently HIV-1-infected cells are poorly understood. The expression and activation of TCR components and its downstream molecules in acutely and latently HIV-1-infected T cells were compared using quantitative reverse transcription polymerase chain reaction (RT-PCR) for mRNA expression and enzyme-linked immunosorbent assay (ELISA) for levels of IL-2 in phytohemagglutinin M (PHA-M). The levels of T cell surface molecules and TCR signaling molecules in latently HIV-1-infected cells were greatly decreased without changes in their mRNA levels. In addition, downstream TCR-signaling molecules in latently HIV-1-infected cells were not activated even in the presence of PHA-M. The phosphorylation of mitogen-activated protein kinases (MAPKs) in the presence of PHA-M was weakly induced in latently HIV-1-infected cells but was greater in acutely HIVNL4-3-infected cells. Finally, the production of IL-2 was significantly decreased in latently HIV-1-infected cells compared with uninfected parent cells. Thus, IL-2-related immunological functions in latently HIV-1-infected T cells were markedly impaired even in the presence of stimuli.

  7. Disseminated human immunodeficiency virus 1 (HIV-1) infection in SCID- hu mice after peripheral inoculation with HIV-1

    PubMed Central

    1994-01-01

    expression of human cytokines shown to enhance HIV-1 replication was examined. Significantly more of the HIV-1-infected SCID-hu mice expressed mRNA for human tumor necrosis factors alpha and beta, and interleukin 2 in their spleens, lymph nodes, and PBMC than did uninfected SCID-hu mice. This suggested that HIV-1 infection in vivo can stimulate the expression of cytokine mRNA by human T cells.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:8294863

  8. HIV-1 Capsid Stabilization Assay.

    PubMed

    Fricke, Thomas; Diaz-Griffero, Felipe

    2016-01-01

    The stability of the HIV-1 core in the cytoplasm is crucial for productive HIV-1 infection. Mutations that stabilize or destabilize the core showed defects in HIV-1 reverse transcription and infection. We developed a novel and simple assay to measure stability of in vitro-assembled HIV-1 CA-NC complexes. This assay allowed us to demonstrate that cytosolic extracts strongly stabilize the HIV-1 core (Fricke et al., J Virol 87:10587-10597, 2013). By using our novel assay, one can measure the ability of different drugs to modulate the stability of in vitro-assembled HIV-1 CA-NC complexes, such as PF74, CAP-1, IXN-053, cyclosporine A, Bi2, and the peptide CAI. We also found that purified CPSF6 (1-321) protein stabilizes in vitro-assembled HIV-1 CA-NC complexes (Fricke et al., J Virol 87:10587-10597, 2013). Here we describe in detail the use of this capsid stability assay. We believe that our assay can be a powerful tool to assess HIV-1 capsid stability in vitro.

  9. APOBEC3H Haplotypes and HIV-1 Pro-Viral vif DNA Sequence Diversity in Early Untreated HIV-1 Infection

    PubMed Central

    Gourraud, PA; Karaouni, A; Woo, JM; Schmidt, T; Oksenberg, JR; Hecht, FM; Liegler, TJ; Barbour, JD

    2011-01-01

    We examined single nucleotide polymorphisms (SNP) in the APOBEC3 locus on chromosome 22, paired to population sequences of pro-viral HIV-1 vif of peripheral blood mononuclear cells (PBMC), from 96 recently HIV-1 infected treatment naïve adults. We found evidence for the existence of an APOBEC3H linkage disequilibrium (LD) block associated with variation in GA->AA, or APOBEC3F signature, sequence changes in pro-viral HIV-1 vif sequence (top significant 10 SNPs with a top-significant p=4.8×10−3). We identified a common 5 position risk haplotype distal to APOBEC3H (A3Hrh). These markers were in high LD (D′ = 1; r2=0.98) to a previously described A3H ‘RED’ haplotype containing a variant (E121) with enhanced susceptibility to HIV-1 Vif (Zhen et al 2009 [1]). This association is confirmed by a haplotype analysis: Homozygote carriers of the A3Hrh had lower GA->AA (A3F) sequence editing on pro-viral HIV-1 vif sequence (p = 0.01), and lower HIV-1 RNA levels over time during early, untreated HIV-1 infection, (p = 0.015 mixed effects model). This effect may be due to enhanced susceptibility of A3H forms to HIV-1 Vif mediated viral suppression of sequence editing activity, slowing viral diversification and escape from immune responses. PMID:21167246

  10. Lipophosphoglycan blocks attachment of Leishmania major amastigotes to macrophages.

    PubMed Central

    Kelleher, M; Moody, S F; Mirabile, P; Osborn, A H; Bacic, A; Handman, E

    1995-01-01

    Promastigotes of the intracellular protozoan parasite Leishmania major invade mononuclear phagocytes by a direct interaction between the cell surface lipophosphoglycan found on all Leishmania species and macrophage receptors. This interaction is mediated by phosphoglycan repeats containing oligomers of beta (1-3)Gal residues specific to L. major. We show here that although amastigotes also use lipophosphoglycan to bind to both primary macrophages and a cell line, this interaction is independent of the beta (1-3)Gal residues employed by promastigotes. Binding of amastigotes to macrophages could be blocked by intact lipophosphoglycan from L. major amastigotes as well as by lipophosphoglycan from promastigotes of several other Leishmania species, suggesting involvement of a conserved domain. Binding of amastigotes to macrophages could be blocked significantly by the monoclonal antibody WIC 108.3, directed to the lipophosphoglycan backbone. The glycan core of lipophosphoglycan could also inhibit attachment of amastigotes, but to a considerably lesser extent. The glycan core structure is also present in the type 2 glycoinositolphospholipids which are expressed on the surface of amastigotes at 100-fold-higher levels than lipophosphoglycan. However, their inhibitory effect could not be increased even when they were used at a 300-fold-higher concentration than lipophosphoglycan, indicating that lipophosphoglycan is the major macrophage-binding molecule on amastigotes of L. major. In the presence of complement, the attachment of amastigotes to macrophages was not altered, suggesting that lipophosphoglycan interacts directly with macrophage receptors. PMID:7806383

  11. The Complex Interaction between Methamphetamine Abuse and HIV-1 pathogenesis

    PubMed Central

    Passaro, Ryan Colby; Pandhare, Jui; Qian, Han-Zhu; Dash, Chandravanu

    2016-01-01

    The global HIV/AIDS pandemic has claimed the lives of an estimated 35 million people. A significant barrier for combating this global pandemic is substance use since it is associated with HIV transmission, delayed diagnosis/initiation of therapy, and poor adherence to therapy. Clinical studies also suggest a link between substance use and HIV-disease progression/AIDS-associated mortality. Methamphetamine (METH) use is one of the fastest-growing substance use problems in the world. METH use enhances high-risk sexual behaviors, therefore increases the likelihood of HIV-1 acquisition. METH use is also associated with higher viral loads, immune dysfunction, and antiretroviral resistance. Moreover, METH use has also been correlated with rapid progression to AIDS. However, direct effects of METH on HIV-1 disease progression remains poorly understood because use of METH and other illicit drugs is often associated with reduced/non adherence to ART. Nevertheless, in vitro studies demonstrate that METH increases HIV-1 replication in cell cultures and animal models. Thus, it has been proposed that METH’s potentiating effects on HIV-1 replication may in part contribute to the worsening of HIV-1 pathogenesis. However, our recent data demonstrate that METH inhibits HIV-1 replication in CD4+ T cells and challenges this paradigm. Thus, the goal of this review is to systematically examine the published literature to better understand the complex interaction between METH abuse and HIV-1 disease progression. PMID:25850893

  12. Authentic HIV-1 integrase inhibitors

    PubMed Central

    Liao, Chenzhong; Marchand, Christophe; Burke, Terrence R; Pommier, Yves; Nicklaus, Marc C

    2010-01-01

    HIV-1 integrase (IN) is indispensable for HIV-1 replication and has become a validated target for developing anti-AIDS agents. In two decades of development of IN inhibition-based anti-HIV therapeutics, a significant number of compounds were identified as IN inhibitors, but only some of them showed antiviral activity. This article reviews a number of patented HIV-1 IN inhibitors, especially those that possess high selectivity for the strand transfer reaction. These compounds generally have a polar coplanar moiety, which is assumed to chelate two magnesium ions in the binding site. Resistance to those compounds, when given to patients, can develop as a result of IN mutations. We refer to those compounds as authentic IN inhibitors. Continued drug development has so far delivered one authentic IN inhibitor to the market (raltegravir in 2007). Current and future attention will be focused on the development of novel authentic IN inhibitors with the goal of overcoming viral resistance. PMID:21426159

  13. Association of HIV-1 Envelope-Specific Breast Milk IgA Responses with Reduced Risk of Postnatal Mother-to-Child Transmission of HIV-1

    PubMed Central

    Pollara, Justin; McGuire, Erin; Fouda, Genevieve G.; Rountree, Wes; Eudailey, Josh; Overman, R. Glenn; Seaton, Kelly E.; Deal, Aaron; Edwards, R. Whitney; Tegha, Gerald; Kamwendo, Deborah; Kumwenda, Jacob; Nelson, Julie A. E.; Liao, Hua-Xin; Brinkley, Christie; Denny, Thomas N.; Ochsenbauer, Christina; Ellington, Sascha; King, Caroline C.; Jamieson, Denise J.; van der Horst, Charles; Kourtis, Athena P.; Tomaras, Georgia D.; Ferrari, Guido

    2015-01-01

    ABSTRACT Infants born to HIV-1-infected mothers in resource-limited areas where replacement feeding is unsafe and impractical are repeatedly exposed to HIV-1 throughout breastfeeding. Despite this, the majority of infants do not contract HIV-1 postnatally, even in the absence of maternal antiretroviral therapy. This suggests that immune factors in breast milk of HIV-1-infected mothers help to limit vertical transmission. We compared the HIV-1 envelope-specific breast milk and plasma antibody responses of clade C HIV-1-infected postnatally transmitting and nontransmitting mothers in the control arm of the Malawi-based Breastfeeding Antiretrovirals and Nutrition Study using multivariable logistic regression modeling. We found no association between milk or plasma neutralization activity, antibody-dependent cell-mediated cytotoxicity, or HIV-1 envelope-specific IgG responses and postnatal transmission risk. While the envelope-specific breast milk and plasma IgA responses also did not reach significance in predicting postnatal transmission risk in the primary model after correction for multiple comparisons, subsequent exploratory analysis using two distinct assay methodologies demonstrated that the magnitudes of breast milk total and secretory IgA responses against a consensus HIV-1 envelope gp140 (B.con env03) were associated with reduced postnatal transmission risk. These results suggest a protective role for mucosal HIV-1 envelope-specific IgA responses in the context of postnatal virus transmission. This finding supports further investigations into the mechanisms by which mucosal IgA reduces risk of HIV-1 transmission via breast milk and into immune interventions aimed at enhancing this response. IMPORTANCE Infants born to HIV-1-infected mothers are repeatedly exposed to the virus in breast milk. Remarkably, the transmission rate is low, suggesting that immune factors in the breast milk of HIV-1-infected mothers help to limit transmission. We compared the antibody

  14. COMMD1/Murr1 Reinforces HIV-1 Latent Infection through IκB-α Stabilization

    PubMed Central

    Taura, Manabu; Kudo, Eriko; Kariya, Ryusho; Goto, Hiroki; Matsuda, Kouki; Hattori, Shinichiro; Vaeteewoottacharn, Kulthida; McDonald, Fiona; Suico, Mary Ann; Shuto, Tsuyoshi; Kai, Hirofumi

    2014-01-01

    ABSTRACT The transcription factor NF-κB is important for HIV-1 transcription initiation in primary HIV-1 infection and reactivation in latently HIV-1-infected cells. However, comparative analysis of the regulation and function of NF-κB in latently HIV-1-infected cells has not been done. Here we show that the expression of IκB-α, an endogenous inhibitor of NF-κB, is enhanced by latent HIV-1 infection via induction of the host-derived factor COMMD1/Murr1 in myeloid cells but not in lymphoid cells by using four sets of latently HIV-1-infected cells and the respective parental cells. IκB-α protein was stabilized by COMMD1, which attenuated NF-κB signaling during Toll-like receptor ligand and tumor necrosis factor alpha treatment and enhanced HIV-1 latency in latently HIV-1-infected cells. Activation of the phosphoinositol 3-kinase (PI3K)–JAK pathway is involved in COMMD1 induction in latently HIV-1-infected cells. Our findings indicate that COMMD1 induction is the NF-κB inhibition mechanism in latently HIV-1-infected cells that contributes to innate immune deficiency and reinforces HIV-1 latency. Thus, COMMD1 might be a double-edged sword that is beneficial in primary infection but not beneficial in latent infection when HIV-1 eradication is considered. IMPORTANCE HIV-1 latency is a major barrier to viral eradication in the era of combination antiretroviral therapy. In this study, we found that COMMD1/Murr1, previously identified as an HIV-1 restriction factor, inhibits the proteasomal degradation of IκB-α by increasing the interaction with IκB-α in latently HIV-1-infected myeloid cells. IκB-α protein was stabilized by COMMD1, which attenuated NF-κB signaling during the innate immune response and enhanced HIV-1 latency in latently HIV-1-infected cells. Activation of the PI3K-JAK pathway is involved in COMMD1 induction in latently HIV-1-infected cells. Thus, the host-derived factor COMMD1 is beneficial in suppressing primary infection but enhances

  15. Broadly Neutralizing Antibody VRC01 Prevents HIV-1 Transmission from Plasmacytoid Dendritic Cells to CD4 T Lymphocytes

    PubMed Central

    Lederle, Alexandre; Laumond, Géraldine; Ducloy, Camille; Schmidt, Sylvie; Decoville, Thomas

    2014-01-01

    Plasmacytoid dendritic cells (pDC) poorly replicate human immunodeficiency virus type 1 (HIV-1) but efficiently transfer HIV-1 to adjacent CD4 T lymphocytes. We found that coculture with T lymphocytes downregulates SAMHD1 expression, enhances HIV-1 replication, and increases pDC maturation and alpha interferon (IFN-α) secretion. HIV-1 transfer to T lymphocytes is inhibited by broadly neutralizing antibody VRC01 with efficiency similar to that of cell-free infection of T lymphocytes. Interestingly, prevention of HIV-1 transmission by VRC01 retains IFN-α secretion. These results emphasize the multiple functions of VRC01 in protection against HIV-1 acquisition. PMID:24965460

  16. HIV-1 antiretroviral drug therapy.

    PubMed

    Arts, Eric J; Hazuda, Daria J

    2012-04-01

    The most significant advance in the medical management of HIV-1 infection has been the treatment of patients with antiviral drugs, which can suppress HIV-1 replication to undetectable levels. The discovery of HIV-1 as the causative agent of AIDS together with an ever-increasing understanding of the virus replication cycle have been instrumental in this effort by providing researchers with the knowledge and tools required to prosecute drug discovery efforts focused on targeted inhibition with specific pharmacological agents. To date, an arsenal of 24 Food and Drug Administration (FDA)-approved drugs are available for treatment of HIV-1 infections. These drugs are distributed into six distinct classes based on their molecular mechanism and resistance profiles: (1) nucleoside-analog reverse transcriptase inhibitors (NNRTIs), (2) non-nucleoside reverse transcriptase inhibitors (NNRTIs), (3) integrase inhibitors, (4) protease inhibitors (PIs), (5) fusion inhibitors, and (6) coreceptor antagonists. In this article, we will review the basic principles of antiretroviral drug therapy, the mode of drug action, and the factors leading to treatment failure (i.e., drug resistance).

  17. Structural basis for enhanced neutralization of HIV-1 by a dimeric IgG form of the glycan-recognizing antibody 2G12

    PubMed Central

    Wu, Yunji; West, Anthony P.; Kim, Helen J.; Thornton, Matthew E.; Ward, Andrew B.; Bjorkman, Pamela J.

    2013-01-01

    SUMMARY The human IgG 2G12 recognizes high-mannose carbohydrates on the HIV-1 envelope glycoprotein gp120. Its two antigen-binding fragments (Fabs) are intramolecularly domain exchanged, resulting in a rigid (Fab)2 unit including a third antigen-binding interface not found in antibodies with flexible Fab arms. We determined crystal structures of dimeric 2G12 IgG created by intermolecular domain exchange, which exhibits increased breadth and >50-fold increased neutralization potency compared with monomeric 2G12. The four Fab and two Fc regions of dimeric 2G12 were localized at low resolution in two independent structures, revealing IgG dimers with two (Fab)2 arms analogous to the Fabs of conventional monomeric IgGs. Structures revealed three conformationally-distinct dimers, demonstrating flexibility of the (Fab)2–Fc connections that was confirmed by electron microscopy, small-angle X-ray scattering, and binding studies. We conclude that intermolecular domain exchange, flexibility, and bivalent binding to allow avidity effects are responsible for the increased potency and breadth of dimeric 2G12. PMID:24316082

  18. Phenotypic Correlates of HIV-1 Macrophage Tropism

    PubMed Central

    Arrildt, Kathryn T.; LaBranche, Celia C.; Joseph, Sarah B.; Dukhovlinova, Elena N.; Graham, William D.; Ping, Li-Hua; Schnell, Gretja; Sturdevant, Christa B.; Kincer, Laura P.; Mallewa, Macpherson; Heyderman, Robert S.; Van Rie, Annelies; Cohen, Myron S.; Spudich, Serena; Price, Richard W.; Montefiori, David C.

    2015-01-01

    ABSTRACT HIV-1 is typically CCR5 using (R5) and T cell tropic (T-tropic), targeting memory CD4+ T cells throughout acute and chronic infections. However, viruses can expand into alternative cells types. Macrophage-tropic (M-tropic) HIV-1 variants have evolved to infect macrophages, which have only low levels of surface CD4. Most M-tropic variants have been isolated from the central nervous system during late-stage chronic infection. We used the HIV-1 env genes of well-defined, subject-matched M-tropic and T-tropic viruses to characterize the phenotypic features of the M-tropic Env protein. We found that, compared to T-tropic viruses, M-tropic viruses infect monocyte-derived macrophages (MDMs) on average 28-fold more efficiently, use low-density CD4 more efficiently, have increased sensitivity to soluble CD4 (sCD4), and show trends toward sensitivity to some CD4 binding site antibodies but no difference in sensitivity to antibodies targeting the CD4-bound conformation. M-tropic viruses also displayed a trend toward resistance to neutralization by monoclonal antibodies targeting the V1/V2 region of Env, suggesting subtle changes in Env protein conformation. The paired M- and T-tropic viruses did not differ in autologous serum neutralization, temperature sensitivity, entry kinetics, intrinsic infectivity, or Env protein incorporation. We also examined viruses with modestly increased CD4 usage. These variants have significant sensitivity to sCD4 and may represent evolutionary intermediates. CD4 usage is strongly correlated with infectivity of MDMs over a wide range of CD4 entry phenotypes. These data suggest that emergence of M-tropic HIV-1 includes multiple steps in which a phenotype of increased sensitivity to sCD4 and enhanced CD4 usage accompany subtle changes in Env conformation. IMPORTANCE HIV-1 typically replicates in CD4+ T cells. However, HIV-1 can evolve to infect macrophages, especially within the brain. Understanding how CCR5-using macrophage-tropic viruses

  19. Lentiviral vectors encoding human immunodeficiency virus type 1 (HIV-1)-specific T-cell receptor genes efficiently convert peripheral blood CD8 T lymphocytes into cytotoxic T lymphocytes with potent in vitro and in vivo HIV-1-specific inhibitory activity.

    PubMed

    Joseph, Aviva; Zheng, Jian Hua; Follenzi, Antonia; Dilorenzo, Teresa; Sango, Kaori; Hyman, Jaime; Chen, Ken; Piechocka-Trocha, Alicja; Brander, Christian; Hooijberg, Erik; Vignali, Dario A; Walker, Bruce D; Goldstein, Harris

    2008-03-01

    The human immunodeficiency virus type 1 (HIV-1)-specific CD8 cytotoxic T-lymphocyte (CTL) response plays a critical role in controlling HIV-1 replication. Augmenting this response should enhance control of HIV-1 replication and stabilize or improve the clinical course of the disease. Although cytomegalovirus (CMV) or Epstein-Barr virus (EBV) infection in immunocompromised patients can be treated by adoptive transfer of ex vivo-expanded CMV- or EBV-specific CTLs, adoptive transfer of ex vivo-expanded, autologous HIV-1-specific CTLs had minimal effects on HIV-1 replication, likely a consequence of the inherently compromised qualitative function of HIV-1-specific CTLs derived from HIV-1-infected individuals. We hypothesized that this limitation could be circumvented by using as an alternative source of HIV-1-specific CTLs, autologous peripheral CD8(+) T lymphocytes whose antigen specificity is redirected by transduction with lentiviral vectors encoding HIV-1-specific T-cell receptor (TCR) alpha and beta chains, an approach used successfully in cancer therapy. To efficiently convert peripheral CD8 lymphocytes into HIV-1-specific CTLs that potently suppress in vivo HIV-1 replication, we constructed lentiviral vectors encoding the HIV-1-specific TCR alpha and TCR beta chains cloned from a CTL clone specific for an HIV Gag epitope, SL9, as a single transcript linked with a self-cleaving peptide. We demonstrated that transduction with this lentiviral vector efficiently converted primary human CD8 lymphocytes into HIV-1-specific CTLs with potent in vitro and in vivo HIV-1-specific activity. Using lentiviral vectors encoding an HIV-1-specific TCR to transform peripheral CD8 lymphocytes into HIV-1-specific CTLs with defined specificities represents a new immunotherapeutic approach to augment the HIV-1-specific immunity of infected patients.

  20. Neutralizing antibodies decrease the envelope fluidity of HIV-1

    SciTech Connect

    Harada, Shinji Monde, Kazuaki; Tanaka, Yuetsu; Kimura, Tetsuya; Maeda, Yosuke; Yusa, Keisuke

    2008-01-05

    For successful penetration of HIV-1, the formation of a fusion pore may be required in order to accumulate critical numbers of fusion-activated gp41 with the help of fluidization of the plasma membrane and viral envelope. An increase in temperature to 40 {sup o}C after viral adsorption at 25 {sup o}C enhanced the infectivity by 1.4-fold. The enhanced infectivity was inhibited by an anti-CXCR4 peptide, T140, and anti-V3 monoclonal antibodies (0.5{beta} and 694/98-D) by post-attachment neutralization, but not by non-neutralizing antibodies (670-30D and 246-D) specific for the C5 of gp120 and cluster I of gp41, respectively. Anti-HLA-II and an anti-HTLV-I gp46 antibody, LAT27, neutralized the molecule-carrying HIV-1{sub C-2(MT-2)}. The anti-V3 antibodies suppressed the fluidity of the HIV-1{sub C-2} envelope, whereas the non-neutralizing antibodies did not. The anti-HLA-II antibody decreased the envelope fluidity of HIV-1{sub C-2(MT-2)}, but not that of HIV-1{sub C-2}. Therefore, fluidity suppression by these antibodies represents an important neutralization mechanism, in addition to inhibition of viral attachment.

  1. Regional Differences in Prevalence of HIV-1 Discordance in Africa and Enrollment of HIV-1 Discordant Couples into an HIV-1 Prevention Trial

    PubMed Central

    Lingappa, Jairam R.; Lambdin, Barrot; Bukusi, Elizabeth Ann; Ngure, Kenneth; Kavuma, Linda; Inambao, Mubiana; Kanweka, William; Allen, Susan; Kiarie, James N.; Makhema, Joseph; Were, Edwin; Manongi, Rachel; Coetzee, David; de Bruyn, Guy; Delany-Moretlwe, Sinead; Magaret, Amalia; Mugo, Nelly; Mujugira, Andrew; Ndase, Patrick; Celum, Connie

    2008-01-01

    Background Most HIV-1 transmission in Africa occurs among HIV-1-discordant couples (one partner HIV-1 infected and one uninfected) who are unaware of their discordant HIV-1 serostatus. Given the high HIV-1 incidence among HIV-1 discordant couples and to assess efficacy of interventions for reducing HIV-1 transmission, HIV-1 discordant couples represent a critical target population for HIV-1 prevention interventions and prevention trials. Substantial regional differences exist in HIV-1 prevalence in Africa, but regional differences in HIV-1 discordance among African couples, has not previously been reported. Methodology/Principal Findings The Partners in Prevention HSV-2/HIV-1 Transmission Trial (“Partners HSV-2 Study”), the first large HIV-1 prevention trial in Africa involving HIV-1 discordant couples, completed enrollment in May 2007. Partners HSV-2 Study recruitment data from 12 sites from East and Southern Africa were used to assess HIV-1 discordance among couples accessing couples HIV-1 counseling and testing, and to correlate with enrollment of HIV-1 discordant couples. HIV-1 discordance at Partners HSV-2 Study sites ranged from 8–31% of couples tested from the community. Across all study sites and, among all couples with one HIV-1 infected partner, almost half (49%) of couples were HIV-1 discordant. Site-specific monthly enrollment of HIV-1 discordant couples into the clinical trial was not directly associated with prevalence of HIV-1 discordance, but was modestly correlated with national HIV-1 counseling and testing rates and access to palliative care/basic health care (r = 0.74, p = 0.09). Conclusions/Significance HIV-1 discordant couples are a critical target for HIV-1 prevention in Africa. In addition to community prevalence of HIV-1 discordance, national infrastructure for HIV-1 testing and healthcare delivery and effective community outreach strategies impact recruitment of HIV-1 discordant couples into HIV-1 prevention trials. PMID

  2. Translational regulation of HIV-1 replication by HIV-1 Rev cellular cofactors Sam68, eIF5A, hRIP, and DDX3.

    PubMed

    Liu, Jinfeng; Henao-Mejia, Jorge; Liu, Hao; Zhao, Yingren; He, Johnny J

    2011-06-01

    Nuclear export and translation of HIV-1 RNA are two important posttranscriptional events for HIV-1 gene expression and replication. HIV-1 Rev functions to export unspliced and incompletely spliced HIV-1 RNA from the nucleus to the cytoplasm; it requires interaction with several cellular cofactors such as Sam68, eIF5A, hRIP, and DDX3. Meanwhile, some studies have also implicated Rev and some of its cofactors such as Sam68 in HIV-1 RNA translation. Thus, in this study, we aimed to characterize the potential function of all these four Rev cofactors in HIV-1 RNA translation. Ectopic expression, siRNA knockdown, and trans-complementation assays confirmed that all these cofactors were very important for HIV-1 gene expression and production through Rev and, accordingly, Rev-dependent reporter gene expression. Importantly, these studies revealed for the first time that each of these cofactors also regulated Rev-independent reporter gene expression. To directly determine the roles of these cofactors in HIV-1 RNA translation, we designed and synthesized a full-length capped HIV-1 RNA in vitro, transfected it into cells to bypass the RNA nuclear export step, and determined HIV-1 Gag expression from the cytoplasmic RNA in the cells that had ectopically expressed or siRNA knocked down cofactors. Gag expression was found to closely correlate with the expression levels of all these cofactors. Furthermore, we took advantage of a HIV-1 internal ribosomal entry site (IRES)-based bicistronic reporter gene assay and determined the effects of these cofactors on cap-independent IRES-mediated HIV-1 translation. The results showed that DDX3, eIF5A, and hRIP enhanced HIV-1 IRES-mediated translation, whereas Sam68 did not. Taken together, these results show that HIV-1 Rev cofactors Sam68, eIF5A, hRIP, and DDX3 also function in the translation of HIV-1 RNA and suggest that the regulatory mechanisms of HIV-1 RNA translation are likely different among these cofactors.

  3. Bioinformatic Analysis of HIV-1 Entry and Pathogenesis

    PubMed Central

    Aiamkitsumrit, Benjamas; Dampier, Will; Antell, Gregory; Rivera, Nina; Martin-Garcia, Julio; Pirrone, Vanessa; Nonnemacher, Michael R.; Wigdahl, Brian

    2015-01-01

    The evolution of human immunodeficiency virus type 1 (HIV-1) with respect to co-receptor utilization has been shown to be relevant to HIV-1 pathogenesis and disease. The CCR5-utilizing (R5) virus has been shown to be important in the very early stages of transmission and highly prevalent during asymptomatic infection and chronic disease. In addition, the R5 virus has been proposed to be involved in neuroinvasion and central nervous system (CNS) disease. In contrast, the CXCR4-utilizing (X4) virus is more prevalent during the course of disease progression and concurrent with the loss of CD4+ T cells. The dual-tropic virus is able to utilize both co-receptors (CXCR4 and CCR5) and has been thought to represent an intermediate transitional virus that possesses properties of both X4 and R5 viruses that can be encountered at many stages of disease. The use of computational tools and bioinformatic approaches in the prediction of HIV-1 co-receptor usage has been growing in importance with respect to understanding HIV-1 pathogenesis and disease, developing diagnostic tools, and improving the efficacy of therapeutic strategies focused on blocking viral entry. Current strategies have enhanced the sensitivity, specificity, and reproducibility relative to the prediction of co-receptor use; however, these technologies need to be improved with respect to their efficient and accurate use across the HIV-1 subtypes. The most effective approach may center on the combined use of different algorithms involving sequences within and outside of the env-V3 loop. This review focuses on the HIV-1 entry process and on co-receptor utilization, including bioinformatic tools utilized in the prediction of co-receptor usage. It also provides novel preliminary analyses for enabling identification of linkages between amino acids in V3 with other components of the HIV-1 genome and demonstrates that these linkages are different between X4 and R5 viruses. PMID:24862329

  4. HIV-1, human interaction database: current status and new features.

    PubMed

    Ako-Adjei, Danso; Fu, William; Wallin, Craig; Katz, Kenneth S; Song, Guangfeng; Darji, Dakshesh; Brister, J Rodney; Ptak, Roger G; Pruitt, Kim D

    2015-01-01

    The 'Human Immunodeficiency Virus Type 1 (HIV-1), Human Interaction Database', available through the National Library of Medicine at http://www.ncbi.nlm.nih.gov/genome/viruses/retroviruses/hiv-1/interactions, serves the scientific community exploring the discovery of novel HIV vaccine candidates and therapeutic targets. Each HIV-1 human protein interaction can be retrieved without restriction by web-based downloads and ftp protocols and includes: Reference Sequence (RefSeq) protein accession numbers, National Center for Biotechnology Information Gene identification numbers, brief descriptions of the interactions, searchable keywords for interactions and PubMed identification numbers (PMIDs) of journal articles describing the interactions. In addition to specific HIV-1 protein-human protein interactions, included are interaction effects upon HIV-1 replication resulting when individual human gene expression is blocked using siRNA. A total of 3142 human genes are described participating in 12,786 protein-protein interactions, along with 1316 replication interactions described for each of 1250 human genes identified using small interfering RNA (siRNA). Together the data identifies 4006 human genes involved in 14,102 interactions. With the inclusion of siRNA interactions we introduce a redesigned web interface to enhance viewing, filtering and downloading of the combined data set.

  5. HIV-1, human interaction database: current status and new features

    PubMed Central

    Ako-Adjei, Danso; Fu, William; Wallin, Craig; Katz, Kenneth S.; Song, Guangfeng; Darji, Dakshesh; Brister, J. Rodney; Ptak, Roger G.; Pruitt, Kim D.

    2015-01-01

    The ‘Human Immunodeficiency Virus Type 1 (HIV-1), Human Interaction Database’, available through the National Library of Medicine at http://www.ncbi.nlm.nih.gov/genome/viruses/retroviruses/hiv-1/interactions, serves the scientific community exploring the discovery of novel HIV vaccine candidates and therapeutic targets. Each HIV-1 human protein interaction can be retrieved without restriction by web-based downloads and ftp protocols and includes: Reference Sequence (RefSeq) protein accession numbers, National Center for Biotechnology Information Gene identification numbers, brief descriptions of the interactions, searchable keywords for interactions and PubMed identification numbers (PMIDs) of journal articles describing the interactions. In addition to specific HIV-1 protein–human protein interactions, included are interaction effects upon HIV-1 replication resulting when individual human gene expression is blocked using siRNA. A total of 3142 human genes are described participating in 12 786 protein–protein interactions, along with 1316 replication interactions described for each of 1250 human genes identified using small interfering RNA (siRNA). Together the data identifies 4006 human genes involved in 14 102 interactions. With the inclusion of siRNA interactions we introduce a redesigned web interface to enhance viewing, filtering and downloading of the combined data set. PMID:25378338

  6. Combinatorial Latency Reactivation for HIV-1 Subtypes and Variants▿ †

    PubMed Central

    Burnett, John C.; Lim, Kwang-il; Calafi, Arash; Rossi, John J.; Schaffer, David V.; Arkin, Adam P.

    2010-01-01

    The eradication of HIV-1 will likely require novel clinical approaches to purge the reservoir of latently infected cells from a patient. We hypothesize that this therapy should target a wide range of latent integration sites, act effectively against viral variants that have acquired mutations in their promoter regions, and function across multiple HIV-1 subtypes. By using primary CD4+ and Jurkat cell-based in vitro HIV-1 latency models, we observe that single-agent latency reactivation therapy is ineffective against most HIV-1 subtypes. However, we demonstrate that the combination of two clinically promising drugs—namely, prostratin and suberoylanilide hydroxamic acid (SAHA)—overcomes the limitations of single-agent approaches and can act synergistically for many HIV-1 subtypes, including A, B, C, D, and F. Finally, by identifying the proviral integration position of latent Jurkat cell clones, we demonstrate that this drug combination does not significantly enhance the expression of endogenous genes nearest to the proviral integration site, indicating that its effects may be selective. PMID:20357084

  7. HIV-1 Vpr Protein Enhances Proteasomal Degradation of MCM10 DNA Replication Factor through the Cul4-DDB1[VprBP] E3 Ubiquitin Ligase to Induce G2/M Cell Cycle Arrest*

    PubMed Central

    Romani, Bizhan; Shaykh Baygloo, Nima; Aghasadeghi, Mohammad Reza; Allahbakhshi, Elham

    2015-01-01

    Human immunodeficiency virus type 1 Vpr is an accessory protein that induces G2/M cell cycle arrest. It is well documented that interaction of Vpr with the Cul4-DDB1[VprBP] E3 ubiquitin ligase is essential for the induction of G2/M arrest. In this study, we show that HIV-1 Vpr indirectly binds MCM10, a eukaryotic DNA replication factor, in a Vpr-binding protein (VprBP) (VprBP)-dependent manner. Binding of Vpr to MCM10 enhanced ubiquitination and proteasomal degradation of MCM10. G2/M-defective mutants of Vpr were not able to deplete MCM10, and we show that Vpr-induced depletion of MCM10 is related to the ability of Vpr to induce G2/M arrest. Our study demonstrates that MCM10 is the natural substrate of the Cul4-DDB1[VprBP] E3 ubiquitin ligase whose degradation is regulated by VprBP, but Vpr enhances the proteasomal degradation of MCM10 by interacting with VprBP. PMID:26032416

  8. HIV-1 Vpr Protein Enhances Proteasomal Degradation of MCM10 DNA Replication Factor through the Cul4-DDB1[VprBP] E3 Ubiquitin Ligase to Induce G2/M Cell Cycle Arrest.

    PubMed

    Romani, Bizhan; Shaykh Baygloo, Nima; Aghasadeghi, Mohammad Reza; Allahbakhshi, Elham

    2015-07-10

    Human immunodeficiency virus type 1 Vpr is an accessory protein that induces G2/M cell cycle arrest. It is well documented that interaction of Vpr with the Cul4-DDB1[VprBP] E3 ubiquitin ligase is essential for the induction of G2/M arrest. In this study, we show that HIV-1 Vpr indirectly binds MCM10, a eukaryotic DNA replication factor, in a Vpr-binding protein (VprBP) (VprBP)-dependent manner. Binding of Vpr to MCM10 enhanced ubiquitination and proteasomal degradation of MCM10. G2/M-defective mutants of Vpr were not able to deplete MCM10, and we show that Vpr-induced depletion of MCM10 is related to the ability of Vpr to induce G2/M arrest. Our study demonstrates that MCM10 is the natural substrate of the Cul4-DDB1[VprBP] E3 ubiquitin ligase whose degradation is regulated by VprBP, but Vpr enhances the proteasomal degradation of MCM10 by interacting with VprBP.

  9. Pandemic Influenza A (H1N1) Virus Infection Increases Apoptosis and HIV-1 Replication in HIV-1 Infected Jurkat Cells.

    PubMed

    Wang, Xue; Tan, Jiying; Biswas, Santanu; Zhao, Jiangqin; Devadas, Krishnakumar; Ye, Zhiping; Hewlett, Indira

    2016-02-02

    Influenza virus infection has a significant impact on public health, since it is a major cause of morbidity and mortality. It is not well-known whether influenza virus infection affects cell death and human immunodeficiency virus (HIV)-1 replication in HIV-1-infected patients. Using a lymphoma cell line, Jurkat, we examined the in vitro effects of pandemic influenza A (H1N1) virus (pH1N1) infection on cell death and HIV-1 RNA production in infected cells. We found that pH1N1 infection increased apoptotic cell death through Fas and Bax-mediated pathways in HIV-1-infected Jurkat cells. Infection with pH1N1 virus could promote HIV-1 RNA production by activating host transcription factors including nuclear factor kappa-light-chain-enhancer of activated B cells (NF-ĸB), nuclear factor of activated T-cells (NFAT) and activator protein 1 (AP-1) through mitogen-activated protein kinases (MAPK) pathways and T-cell antigen receptor (TCR)-related pathways. The replication of HIV-1 latent infection could be reactivated by pH1N1 infection through TCR and apoptotic pathways. These data indicate that HIV-1 replication can be activated by pH1N1 virus in HIV-1-infected cells resulting in induction of cell death through apoptotic pathways.

  10. Leishmania donovani: amastigote inhibition and mode of action of berberine.

    PubMed

    Ghosh, A K; Bhattacharyya, F K; Ghosh, D K

    1985-12-01

    Berberine, an alkaloid from Berberis aristata Linnaeus, may be a useful drug for the treatment of visceral leishmaniasis. In both the 8-day and long-term models of Leishmania donovani infection in hamsters, it markedly diminished the parasitic load and proved to be less toxic than pentamidine. It rapidly improved the hematological picture of infected animals. Like pentamidine, it inhibited in vitro multiplication of amastigotes in macrophage culture and their transformation to promastigotes in cell free culture. Manometric studies showed that both drugs had inhibitory action on both the endogenous and the glucose-stimulated respiration of amastigotes. They inhibited incorporation of [14C]adenine, [14C]uracil, and [3H]thymidine into nucleic acids, and of [14C]leucine into the protein of amastigotes, indicating an inhibitory action on macromolecular biosynthesis. They also decreased deoxyglucose uptake. Using spectrophotometric, spectrofluorimetric, and circular dichroism techniques, berberine was found to interact in vitro with nuclear DNA from L. donovani promastigotes.

  11. Macrophages and HIV-1: An Unhealthy Constellation.

    PubMed

    Sattentau, Quentin J; Stevenson, Mario

    2016-03-01

    Lentiviruses have a long-documented association with macrophages. Abundant evidence exists for in vitro and, in a tissue-specific manner, in vivo infection of macrophages by the primate lentiviruses HIV-1 and SIV. However, macrophage contribution to aspects of HIV-1 and SIV pathogenesis, and their role in viral persistence in individuals on suppressive antiretroviral therapy, remains unclear. Here we discuss recent evidence implicating macrophages in HIV-1-mediated disease and highlight directions for further investigation.

  12. Multiparameter optimization method and enhanced production of secreted recombinant single-chain variable fragment against the HIV-1 P17 protein from Escherichia coli by fed-batch fermentation.

    PubMed

    Paopang, Porntip; Kasinrerk, Watchara; Tayapiwatana, Chatchai; Seesuriyachan, Phisit; Butr-Indr, Bordin

    2016-01-01

    The single-chain fragment variable (scFv) was used to produce a completely functional antigen-binding fragment in bacterial systems. The advancements in antibody engineering have simplified the method of producing Fv fragments and made it more efficient and generally relevant. In a previous study, the scFv anti HIV-1 P17 protein was produced by a batch production system, optimized by the sequential simplex optimization method. This study continued that work in order to enhance secreted scFv production by fed-batch cultivation, which supported high volumetric productivity and provided a large amount of scFvs for diagnostic and therapeutic research. The developments in cell culture media and process parameter settings were required to realize the maximum production of cells. This study investigated the combined optimization methods, Plackett-Burman design (PBD) and sequential simplex optimization, with the aim of optimize feed medium. Fed-batch cultivation with an optimal feeding rate was determined. The result demonstrated that a 20-mL/hr feeding rate of the optimized medium can increase cell growth, total protein production, and scFv anti-p17 activity by 4.43, 1.48, and 6.5 times more than batch cultivation, respectively. The combined optimization method demonstrated novel power tools for the optimization strategy of multiparameter experiments.

  13. Leishmania pifanoi amastigote antigens protect mice against cutaneous leishmaniasis.

    PubMed

    Soong, L; Duboise, S M; Kima, P; McMahon-Pratt, D

    1995-09-01

    In the search for a leishmaniasis vaccine, extensive studies have been carried out with promastigote (insect stage) molecules. Information in this regard on amastigote (mammalian host stage) molecules is limited. To investigate host immune responses to Leishmania amastigote antigens, we purified three stage-specific antigens (A2, P4, and P8) from in vitro-cultivated amastigotes of Leishmania pifanoi by using immunoaffinity chromatography. We found that with Corynebacterium parvum as an adjuvant, three intraperitoneal injections of 5 micrograms of P4 or P8 antigen provided partial to complete protection of BALB/c mice challenged with 10(5) to 10(7) L. pifanoi promastigotes. These immunized mice developed significantly smaller or no lesions and exhibited a 39- to 1.6 x 10(5)-fold reduction of lesion parasite burden after 15 to 20 weeks of infection. In addition, P8 immunization resulted in complete protection against L. amazonensis infection of CBA/J mice and partial protection of BALB/c mice, suggesting that this antigen provided cross-species protection of mice with different H-2 haplotypes. At different stages during infection, vaccinated mice exhibited profound proliferative responses to parasite antigens and increased levels of gamma interferon production, suggesting that a Th1 cell-mediated immune response is associated with the resistance in these mice. Taken together, the data in this report indicate the vaccine potential of amastigote-derived antigens.

  14. Leishmania pifanoi amastigote antigens protect mice against cutaneous leishmaniasis.

    PubMed

    Soong, L; Duboise, S M; Kima, P; McMahon-Pratt, D

    1995-09-01

    In the search for a leishmaniasis vaccine, extensive studies have been carried out with promastigote (insect stage) molecules. Information in this regard on amastigote (mammalian host stage) molecules is limited. To investigate host immune responses to Leishmania amastigote antigens, we purified three stage-specific antigens (A2, P4, and P8) from in vitro-cultivated amastigotes of Leishmania pifanoi by using immunoaffinity chromatography. We found that with Corynebacterium parvum as an adjuvant, three intraperitoneal injections of 5 micrograms of P4 or P8 antigen provided partial to complete protection of BALB/c mice challenged with 10(5) to 10(7) L. pifanoi promastigotes. These immunized mice developed significantly smaller or no lesions and exhibited a 39- to 1.6 x 10(5)-fold reduction of lesion parasite burden after 15 to 20 weeks of infection. In addition, P8 immunization resulted in complete protection against L. amazonensis infection of CBA/J mice and partial protection of BALB/c mice, suggesting that this antigen provided cross-species protection of mice with different H-2 haplotypes. At different stages during infection, vaccinated mice exhibited profound proliferative responses to parasite antigens and increased levels of gamma interferon production, suggesting that a Th1 cell-mediated immune response is associated with the resistance in these mice. Taken together, the data in this report indicate the vaccine potential of amastigote-derived antigens. PMID:7642292

  15. Dual Neonate Vaccine Platform against HIV-1 and M. tuberculosis

    PubMed Central

    Hopkins, Richard; Bridgeman, Anne; Joseph, Joan; Gilbert, Sarah C.; McShane, Helen; Hanke, Tomáš

    2011-01-01

    Acquired immunodeficiency syndrome and tuberculosis (TB) are two of the world's most devastating diseases. The first vaccine the majority of infants born in Africa receive is Mycobacterium bovis bacillus Calmette-Guérin (BCG) as a prevention against TB. BCG protects against disseminated disease in the first 10 years of life, but provides a variable protection against pulmonary TB and enhancing boost delivered by recombinant modified vaccinia virus Ankara (rMVA) expressing antigen 85A (Ag85A) of M. tuberculosis is currently in phase IIb evaluation in African neonates. If the newborn's mother is positive for human immunodeficiency virus type 1 (HIV-1), the baby is at high risk of acquiring HIV-1 through breastfeeding. We suggested that a vaccination consisting of recombinant BCG expressing HIV-1 immunogen administered at birth followed by a boost with rMVA sharing the same immunogen could serve as a strategy for prevention of mother-to-child transmission of HIV-1 and rMVA expressing an African HIV-1-derived immunogen HIVA is currently in phase I trials in African neonates. Here, we aim to develop a dual neonate vaccine platform against HIV-1 and TB consisting of BCG.HIVA administered at birth followed by a boost with MVA.HIVA.85A. Thus, mMVA.HIVA.85A and sMVA.HIVA.85A vaccines were constructed, in which the transgene transcription is driven by either modified H5 or short synthetic promoters, respectively, and tested for immunogenicity alone and in combination with BCG.HIVA222. mMVA.HIVA.85A was produced markerless and thus suitable for clinical manufacture. While sMVA.HIVA.85A expressed higher levels of the immunogens, it was less immunogenic than mMVA.HIVA.85A in BALB/c mice. A BCG.HIVA222–mMVA.HIVA.85A prime-boost regimen induced robust T cell responses to both HIV-1 and M. tuberculosis. Therefore, proof-of-principle for a dual anti-HIV-1/M. tuberculosis infant vaccine platform is established. Induction of immune responses against these pathogens soon after

  16. Stimulation of HIV-1 Replication in Immature Dendritic Cells in Contact with Primary CD4 T or B Lymphocytes ▿

    PubMed Central

    Holl, Vincent; Xu, Ke; Peressin, Maryse; Lederle, Alexandre; Biedma, Marina Elizabeth; Delaporte, Maryse; Decoville, Thomas; Schmidt, Sylvie; Laumond, Géraldine; Aubertin, Anne-Marie; Moog, Christiane

    2010-01-01

    Sexual transmission is the major route of HIV-1 infection worldwide. Dendritic cells (DCs) from the mucosal layers are considered to be the initial targets of HIV-1 and probably play a crucial role in HIV-1 transmission. We investigated the role of cell-to-cell contact between HIV-1-exposed immature DCs and various lymphocyte subsets in the stimulation of HIV-1 replication. We found that HIV-1 replication and production in DCs were substantially enhanced by the coculture of DCs with primary CD4 T or nonpermissive B lymphocytes but not with primary activated CD8 T lymphocytes or human transformed CD4 T lymphocytes. Most of the new virions released by cocultures of HIV-1-exposed immature DCs and primary B lymphocytes expressed the DC-specific marker CD1a and were infectious for both immature DCs and peripheral blood mononuclear cells (PBMCs). Cocultured DCs thus produced large numbers of infectious viral particles under these experimental conditions. The soluble factors present in the supernatants of the cocultures were not sufficient to enhance HIV-1 replication in DCs, for which cell-to-cell contact was required. The neutralizing monoclonal antibody IgG1b12 and polyclonal anti-HIV-1 sera efficiently blocked HIV-1 transfer to CD4 T lymphocytes but did not prevent the increase in viral replication in DCs. Neutralizing antibodies thus proved to be more efficient at blocking HIV-1 transfer than previously thought. Our findings show that HIV-1 exploits DC-lymphocyte cross talk to upregulate replication within the DC reservoir. We provide evidence for a novel mechanism that may facilitate HIV-1 replication and transmission. This mechanism may favor HIV-1 pathogenesis, immune evasion, and persistence. PMID:20147388

  17. New insights into HIV-1-primary skin disorders.

    PubMed

    Cedeno-Laurent, Filiberto; Gómez-Flores, Minerva; Mendez, Nora; Ancer-Rodríguez, Jesús; Bryant, Joseph L; Gaspari, Anthony A; Trujillo, Jose R

    2011-01-24

    Since the first reports of AIDS, skin involvement has become a burdensome stigma for seropositive patients and a challenging task for dermatologist and infectious disease specialists due to the severe and recalcitrant nature of the conditions. Dermatologic manifestations in AIDS patients act as markers of disease progression, a fact that enhances the importance of understanding their pathogenesis.Broadly, cutaneous disorders associated with HIV type-1 infection can be classified as primary and secondary. While the pathogenesis of secondary complications, such as opportunistic infections and skin tumours, is directly correlated with a decline in the CD4+ T cell count, the origin of the certain manifestations primarily associated with the retroviral infection itself still remains under investigation.The focus of this review is to highlight the immunological phenomena that occur in the skin of HIV-1-seropositive patients, which ultimately lead to skin disorders, such as seborrhoeic dermatitis, atopic dermatitis, psoriasis and eosinophilic folliculitis. Furthermore, we compile the latest data on how shifts in the cytokines milieu, impairments of the innate immune compartment, reactions to xenobiotics and autoimmunity are causative agents in HIV-1-driven skin diseases. Additionally, we provide a thorough analysis of the small animal models currently used to study HIV-1-associated skin complications, centering on transgenic rodent models, which unfortunately, have not been able to fully unveil the role of HIV-1 genes in the pathogenesis of their primarily associated dermatological manifestations.

  18. New insights into HIV-1-primary skin disorders

    PubMed Central

    2011-01-01

    Since the first reports of AIDS, skin involvement has become a burdensome stigma for seropositive patients and a challenging task for dermatologist and infectious disease specialists due to the severe and recalcitrant nature of the conditions. Dermatologic manifestations in AIDS patients act as markers of disease progression, a fact that enhances the importance of understanding their pathogenesis. Broadly, cutaneous disorders associated with HIV type-1 infection can be classified as primary and secondary. While the pathogenesis of secondary complications, such as opportunistic infections and skin tumours, is directly correlated with a decline in the CD4+ T cell count, the origin of the certain manifestations primarily associated with the retroviral infection itself still remains under investigation. The focus of this review is to highlight the immunological phenomena that occur in the skin of HIV-1-seropositive patients, which ultimately lead to skin disorders, such as seborrhoeic dermatitis, atopic dermatitis, psoriasis and eosinophilic folliculitis. Furthermore, we compile the latest data on how shifts in the cytokines milieu, impairments of the innate immune compartment, reactions to xenobiotics and autoimmunity are causative agents in HIV-1-driven skin diseases. Additionally, we provide a thorough analysis of the small animal models currently used to study HIV-1-associated skin complications, centering on transgenic rodent models, which unfortunately, have not been able to fully unveil the role of HIV-1 genes in the pathogenesis of their primarily associated dermatological manifestations. PMID:21261982

  19. GADD45 proteins inhibit HIV-1 replication through specific suppression of HIV-1 transcription.

    PubMed

    Liang, Zhibin; Liu, Ruikang; Zhang, Hui; Zhang, Suzhen; Hu, Xiaomei; Tan, Juan; Liang, Chen; Qiao, Wentao

    2016-06-01

    GADD45 proteins are a group of stress-induced proteins and participate in various cellular pathways including cell cycle regulation, cell survival and death, DNA repair and demethylation. It was recently shown that HIV-1 infection induces the expression of GADD45 proteins. However, the effect of GADD45 on HIV-1 replication has not been studied. Here, we report that overexpression of GADD45 proteins reduces HIV-1 production through suppressing transcription from the HIV-1 LTR promoter. This inhibitory effect is specific to HIV-1, since GADD45 proteins neither inhibit the LTR promoters from other retroviruses nor reduce the production of these viruses. Knockdown of endogenous GADD45 modestly activates HIV-1 in the J-Lat A72 latency cell line, which suggests GADD45 proteins might play a role in maintaining HIV-1 latency.

  20. Small Molecule Inhibitors of BAF; A Promising Family of Compounds in HIV-1 Latency Reversal

    PubMed Central

    Stoszko, Mateusz; De Crignis, Elisa; Rokx, Casper; Khalid, Mir Mubashir; Lungu, Cynthia; Palstra, Robert-Jan; Kan, Tsung Wai; Boucher, Charles; Verbon, Annelies; Dykhuizen, Emily C.; Mahmoudi, Tokameh

    2015-01-01

    Persistence of latently infected cells in presence of Anti-Retroviral Therapy presents the main obstacle to HIV-1 eradication. Much effort is thus placed on identification of compounds capable of HIV-1 latency reversal in order to render infected cells susceptible to viral cytopathic effects and immune clearance. We identified the BAF chromatin remodeling complex as a key player required for maintenance of HIV-1 latency, highlighting its potential as a molecular target for inhibition in latency reversal. Here, we screened a recently identified panel of small molecule inhibitors of BAF (BAFi's) for potential to activate latent HIV-1. Latency reversal was strongly induced by BAFi's Caffeic Acid Phenethyl Ester and Pyrimethamine, two molecules previously characterized for clinical application. BAFi's reversed HIV-1 latency in cell line based latency models, in two ex vivo infected primary cell models of latency, as well as in HIV-1 infected patient's CD4 + T cells, without inducing T cell proliferation or activation. BAFi-induced HIV-1 latency reversal was synergistically enhanced upon PKC pathway activation and HDAC-inhibition. Therefore BAFi's constitute a promising family of molecules for inclusion in therapeutic combinatorial HIV-1 latency reversal. PMID:26870822

  1. HIV-1 Infection and the PPARγ-Dependent Control of Adipose Tissue Physiology

    PubMed Central

    Giralt, Marta; Domingo, Pere; Villarroya, Francesc

    2009-01-01

    PPARγ is a ligand-dependent master transcription factor controlling adipocyte differentiation as well as multiple biological processes taking place in other cells present in adipose tissue depots such as macrophages. Recent research indicates that HIV-1 infection-related events may alter adipose tissue biology through several mechanisms involving PPARγ, ranging from direct effects of HIV-1-encoded proteins on adipocytes to the promotion of a proinflammatory environment that interferes with PPARγ actions. This effect of HIV-1 on adipose tissue cells can occur even in the absence of direct infection of adipocytes, as soluble HIV-1-encoded proteins such as Vpr may enter cells and inhibit PPARγ action. Moreover, repression of PPARγ actions may relieve inhibitory pathways of HIV-1 gene transcription, thus enhancing HIV-1 effects in infected cells. HIV-1 infection-mediated interference of PPARγ-dependent pathways in adipocytes and other cells inside adipose depots such as macrophages is likely to create an altered local environment that, after antiretroviral treatment, leads to lipodystrophy in HIV-1-infected and HAART-treated patients. PMID:19081837

  2. Small Molecule Inhibitors of BAF; A Promising Family of Compounds in HIV-1 Latency Reversal.

    PubMed

    Stoszko, Mateusz; De Crignis, Elisa; Rokx, Casper; Khalid, Mir Mubashir; Lungu, Cynthia; Palstra, Robert-Jan; Kan, Tsung Wai; Boucher, Charles; Verbon, Annelies; Dykhuizen, Emily C; Mahmoudi, Tokameh

    2016-01-01

    Persistence of latently infected cells in presence of Anti-Retroviral Therapy presents the main obstacle to HIV-1 eradication. Much effort is thus placed on identification of compounds capable of HIV-1 latency reversal in order to render infected cells susceptible to viral cytopathic effects and immune clearance. We identified the BAF chromatin remodeling complex as a key player required for maintenance of HIV-1 latency, highlighting its potential as a molecular target for inhibition in latency reversal. Here, we screened a recently identified panel of small molecule inhibitors of BAF (BAFi's) for potential to activate latent HIV-1. Latency reversal was strongly induced by BAFi's Caffeic Acid Phenethyl Ester and Pyrimethamine, two molecules previously characterized for clinical application. BAFi's reversed HIV-1 latency in cell line based latency models, in two ex vivo infected primary cell models of latency, as well as in HIV-1 infected patient's CD4 + T cells, without inducing T cell proliferation or activation. BAFi-induced HIV-1 latency reversal was synergistically enhanced upon PKC pathway activation and HDAC-inhibition. Therefore BAFi's constitute a promising family of molecules for inclusion in therapeutic combinatorial HIV-1 latency reversal. PMID:26870822

  3. Vpu-Mediated Counteraction of Tetherin Is a Major Determinant of HIV-1 Interferon Resistance

    PubMed Central

    Kmiec, Dorota; Iyer, Shilpa S.; Stürzel, Christina M.; Sauter, Daniel; Hahn, Beatrice H.

    2016-01-01

    ABSTRACT Human immunodeficiency virus type 1 (HIV-1) groups M, N, O, and P are the result of independent zoonotic transmissions of simian immunodeficiency viruses (SIVs) infecting great apes in Africa. Among these, only Vpu proteins of pandemic HIV-1 group M strains evolved potent activity against the restriction factor tetherin, which inhibits virus release from infected cells. Thus, effective Vpu-mediated tetherin antagonism may have been a prerequisite for the global spread of HIV-1. To determine whether this particular function enhances primary HIV-1 replication and interferon resistance, we introduced mutations into the vpu genes of HIV-1 group M and N strains to specifically disrupt their ability to antagonize tetherin, but not other Vpu functions, such as degradation of CD4, down-modulation of CD1d and NTB-A, and suppression of NF-κB activity. Lack of particular human-specific adaptations reduced the ability of HIV-1 group M Vpu proteins to enhance virus production and release from primary CD4+ T cells at high levels of type I interferon (IFN) from about 5-fold to 2-fold. Interestingly, transmitted founder HIV-1 strains exhibited higher virion release capacity than chronic control HIV-1 strains irrespective of Vpu function, and group M viruses produced higher levels of cell-free virions than an N group HIV-1 strain. Thus, efficient virus release from infected cells seems to play an important role in the spread of HIV-1 in the human population and requires a fully functional Vpu protein that counteracts human tetherin. PMID:27531907

  4. Stage-specific glycosphingolipids from amastigote forms of Leishmania (L.) amazonensis. Immunogenicity and role in parasite binding and invasion of macrophages.

    PubMed

    Straus, A H; Levery, S B; Jasiulionis, M G; Salyan, M E; Steele, S J; Travassos, L R; Hakomori, S; Takahashi, H K

    1993-06-25

    Neutral glycosphingolipids (GSLs) from amastigote forms of Leishmania (L.) amazonensis were isolated, and their structures and biological properties were characterized. Based on various immunochemical methods, these GSLs were shown to be expressed at certain stages of amastigote development. GSLs were extracted and purified from amastigotes of hamster foot lesions by established procedures. Three mouse monoclonal antibodies (MoAbs) specific for carbohydrate epitopes of these GSLs were established, and their inhibition of parasite binding and macrophage invasion was analyzed. MoAb ST-3 inhibited 80% of macrophage invasion by amastigotes and 60% of that by promastigotes. Since GSLs reacting with MoAb ST-3 were found in amastigotes but not in promastigotes, ST-3 reactivity with promastigotes presumably depends on an epitope present on an unidentified promastigote glycoconjugate. MoAbs ST-4 and ST-5 inhibited 60-80% of macrophage invasion by amastigotes but were not effective in preventing macrophage invasion by promastigotes. Fab fragments of ST-3 inhibited invasion of cultured mouse macrophages by amastigotes (80%) or promastigotes (60%). The GSL with the simplest structure recognized by these MoAbs was isolated and characterized (by negative ion fast atom bombardment-mass spectrometry, gas chromatography-mass spectrometry of the permethylated compound, degradation with exoglycosidases, and 1H NMR) as the novel globoseries structure Gal beta 1-->3Gal alpha 1-->4Gal beta 1-->4Glc beta 1-->Cer, which has beta 1-->3Gal in place of the beta 1-->3GalNAc of globoside. The ceramide contains a 16:0 fatty acid and d18:1 sphingosine as the long chain base. The MoAbs also reacted with a series of GSLs from amastigote forms of L. amazonensis, with longer carbohydrate chains, probably containing identical end groups Gal beta 1-->3Gal alpha 1-->R. Expression of surface GSLs may render amastigote forms more effective than promastigotes in binding and invading host macrophages, thus

  5. HIV-1 RNA quantification in CRF02_AG HIV-1 infection: too easy to make mistakes.

    PubMed

    Tatarelli, Paola; Taramasso, Lucia; Di Biagio, Antonio; Sticchi, Laura; Nigro, Nicola; Barresi, Renata; Viscoli, Claudio; Bruzzone, Bianca

    2016-04-01

    The number of patients newly infected by HIV-1 non-B subtypes and circulating recombinant forms (CRFs) is increasing worldwide, including in the western countries. We report on a primary HIV-1 infection in a Caucasian patient. A routine quantitative assay (Nuclisens EasyQ HIV-1 2.0, BioMérieux SA) showed 6,700 HIV-1 RNA copies/ml. A combined antiretroviral therapy (cART) consistent with low baseline HIV-1 RNA was started. Few days later, the analysis performed with REGA HIV-1 Subtyping Tool - Version 3.0 attributed the HIV-1 sequence to the CRF02_AG recombinant form. Therefore, a second real-time PCR assay was performed, using the Versant HIV-1 RNA 1.0 Assay (kPCR) (Siemens HealthCare Diagnostics) which revealed a HIV-1 RNA of 230,000 copies/ml. Consequently, the ongoing cART was potentiated. This case suggests that the wide genetic variability of HIV-1 subtypes may affect the capability of the commonly used assays to detect and accurately quantify HIV-1 RNA in non-B subtypes and CRFs. In presence of CRFs different commercial HIV-1 RNA tests should be performed to find the most reliable for viral load quantification at the diagnosis, because it influences the choice of cART, and during the follow-up. Indeed, international guidelines for HIV-1 infection management suggest to monitor patient' HIV-RNA with the same assay over the course of treatment. As different commercial tests can be performed in the same laboratory with considerable difficulty, the laboratory should select an assay that is suitable not only for the more prevalent strain, but also for less frequent ones that, nevertheless, can occur. Then, knowing and investigating the spread of non-B strains has essential clinical and laboratory implications. PMID:27196556

  6. Antibody-Dependent Cellular Cytotoxicity against Reactivated HIV-1-Infected Cells

    PubMed Central

    Lee, Wen Shi; Richard, Jonathan; Lichtfuss, Marit; Smith, Amos B.; Park, Jongwoo; Courter, Joel R.; Melillo, Bruno N.; Sodroski, Joseph G.; Kaufmann, Daniel E.; Parsons, Matthew S.

    2015-01-01

    ABSTRACT Lifelong antiretroviral therapy (ART) for HIV-1 does not diminish the established latent reservoir. A possible cure approach is to reactivate the quiescent genome from latency and utilize immune responses to eliminate cells harboring reactivated HIV-1. It is not known whether antibodies within HIV-1-infected individuals can recognize and eliminate cells reactivated from latency through antibody-dependent cellular cytotoxicity (ADCC). We found that reactivation of HIV-1 expression in the latently infected ACH-2 cell line elicited antibody-mediated NK cell activation but did not result in antibody-mediated killing. The lack of CD4 expression on these HIV-1 envelope (Env)-expressing cells likely resulted in poor recognition of CD4-induced antibody epitopes on Env. To examine this further, cultured primary CD4+ T cells from HIV-1+ subjects were used as targets for ADCC. These ex vivo-expanded primary cells were modestly susceptible to ADCC mediated by autologous or heterologous HIV-1+ serum antibodies. Importantly, ADCC mediated against these primary cells could be enhanced following incubation with a CD4-mimetic compound (JP-III-48) that exposes CD4-induced antibody epitopes on Env. Our studies suggest that with sufficient reactivation and expression of appropriate Env epitopes, primary HIV-1-infected cells can be targets for ADCC mediated by autologous serum antibodies and innate effector cells. The results of this study suggest that further investigation into the potential of ADCC to eliminate reactivated latently infected cells is warranted. IMPORTANCE An HIV-1 cure remains elusive due to the persistence of long-lived latently infected cells. An HIV-1 cure strategy, termed “shock and kill,” aims to reactivate HIV-1 expression in latently infected cells and subsequently eliminate the reactivated cells through immune-mediated killing. While recent research efforts have focused on reversing HIV-1 latency, it remains unclear whether preexisting immune

  7. Design of HIV-1 Protease Inhibitors with Amino-bis-tetrahydrofuran Derivatives as P2-Ligands to Enhance Backbone-Binding Interactions. Synthesis, Biological Evaluation, and Protein-Ligand X-ray Studies

    SciTech Connect

    Ghosh, Arun K.; Martyr, Cuthbert D.; Osswald, Heather L.; Sheri, Venkat Reddy; Kassekert, Luke A.; Chen, Shujing; Agniswamy, Johnson; Wang, Yuan-Fang; Hayashi, Hironori; Aoki, Manabu; Weber, Irene T.; Mitsuya, Hiroaki

    2015-10-30

    Structure-based design, synthesis, and biological evaluation of a series of very potent HIV-1 protease inhibitors are described. In an effort to improve backbone ligand–binding site interactions, we have incorporated basic-amines at the C4 position of the bis-tetrahydrofuran (bis-THF) ring. We speculated that these substituents would make hydrogen bonding interactions in the flap region of HIV-1 protease. Synthesis of these inhibitors was performed diastereoselectively. A number of inhibitors displayed very potent enzyme inhibitory and antiviral activity. Inhibitors 25f, 25i, and 25j were evaluated against a number of highly-PI-resistant HIV-1 strains, and they exhibited improved antiviral activity over darunavir. Two high resolution X-ray structures of 25f- and 25g-bound HIV-1 protease revealed unique hydrogen bonding interactions with the backbone carbonyl group of Gly48 as well as with the backbone NH of Gly48 in the flap region of the enzyme active site. These ligand–binding site interactions are possibly responsible for their potent activity.

  8. Impact of the Ku complex on HIV-1 expression and latency.

    PubMed

    Manic, Gwenola; Maurin-Marlin, Aurélie; Laurent, Fanny; Vitale, Ilio; Thierry, Sylvain; Delelis, Olivier; Dessen, Philippe; Vincendeau, Michelle; Leib-Mösch, Christine; Hazan, Uriel; Mouscadet, Jean-François; Bury-Moné, Stéphanie

    2013-01-01

    Ku, a cellular complex required for human cell survival and involved in double strand break DNA repair and multiple other cellular processes, may modulate retroviral multiplication, although the precise mechanism through which it acts is still controversial. Recently, Ku was identified as a possible anti-human immunodeficiency virus type 1 (HIV-1) target in human cells, in two global approaches. Here we investigated the role of Ku on the HIV-1 replication cycle by analyzing the expression level of a panel of non-replicative lentiviral vectors expressing the green fluorescent protein in human colorectal carcinoma HCT 116 cells, stably or transiently depleted of Ku. We found that in this cellular model the depletion of Ku did not affect the efficiency of (pre-)integrative steps but decreased the early HIV-1 expression by acting at the transcriptional level. This negative effect was specific of the HIV-1 promoter, required the obligatory step of viral DNA integration and was reversed by transient depletion of p53. We also provided evidence on a direct binding of Ku to HIV-1 LTR in transduced cells. Ku not only promotes the early transcription from the HIV-1 promoter, but also limits the constitution of viral latency. Moreover, in the presence of a normal level of Ku, HIV-1 expression was gradually lost over time, likely due to the counter-selection of HIV-1-expressing cells. On the contrary, the reactivation of transgene expression from HIV-1 by means of trichostatin A- or tumor necrosis factor α-administration was enhanced under condition of Ku haplodepletion, suggesting a phenomenon of provirus latency. These observations plead in favor of the hypothesis that Ku has an impact on HIV-1 expression and latency at early- and mid-time after integration.

  9. Epigenetics of μ-Opioid receptors: Intersection with HIV-1 infection of the Central Nervous System

    PubMed Central

    Regan, Patrick M.; Dave, Rajnish S.; Datta, Prasun K.; Khalili, Kamel

    2014-01-01

    The abuse of intravenous drugs, such as heroin, has become a major public health concern due to the increased risk of HIV-1 infection. Opioids such as heroin were originally identified and subsequently abused for their analgesic effects. However, many investigations have found additional effects of opioids, including regulation of the immune system. As such, chronic opioid abuse has been shown to promote HIV-1 pathogenesis and facilitate HIV-1-associated neurocognitive dysfunction. Clinical opioids, such as morphine and methadone, as well as illicit opioids, such as heroin, exert their effects primarily through interactions with the μ-opioid receptor (MOR). However, the mechanisms by which opioids enhance neurocognitive dysfunction through MOR-mediated signaling pathways are not completely understood. New findings in the regulation of MOR expression, particularly epigenetic and transcriptional regulation as well as alternative splicing, sheds new insights into possible mechanisms of HIV-1 and opiate synergy. In this review, we identify mechanisms regulating MOR expression and propose novel mechanisms by which opioids and HIV-1 may modulate this regulation. Additionally, we suggest that differential regulation of newly identified MOR isoforms by opioids and HIV-1 has functional consequence in enhancing HIV-1 neurocognitive dysfunction. PMID:22034138

  10. Substance abuse, HIV-1 and hepatitis

    PubMed Central

    Parikh, Nirzari; Nonnemacher, Michael R.; Pirrone, Vanessa; Block, Timothy; Mehta, Anand; Wigdahl, Brian

    2013-01-01

    During the course of human immunodeficiency virus type 1 (HIV-1) disease, the virus has been shown to effectively escape the immune response with the subsequent establishment of latent viral reservoirs in specific cell populations within the peripheral blood (PB) and associated lymphoid tissues, bone marrow (BM), brain, and potentially other end organs. HIV-1, along with hepatitis B and C viruses (HBV and HCV), are known to share similar routes of transmission, including intravenous drug use, blood transfusions, sexual intercourse, and perinatal exposure. Substance abuse, including the use of opioids and cocaine, is a significant risk factor for exposure to HIV-1 and the development of acquired immune deficiency syndrome, as well as HBV and HCV exposure, infection, and disease. Thus, coinfection with HIV-1 and HBV or HCV is common and may be impacted by chronic substance abuse during the course of disease. HIV-1 impacts the natural course of HBV and HCV infection by accelerating the progression of HBV/HCV-associated liver disease toward end-stage cirrhosis and quantitative depletion of the CD4+ T-cell compartment. HBV or HCV coinfection with HIV-1 is also associated with increased mortality when compared to either infection alone. This review focuses on the impact of substance abuse and coinfection with HBV and HCV in the PB, BM, and brain on the HIV-1 pathogenic process as it relates to viral pathogenesis, disease progression, and the associated immune response during the course of this complex interplay. The impact of HIV-1 and substance abuse on hepatitis virus-induced disease is also a focal point. PMID:22973853

  11. Exosomes: Implications in HIV-1 Pathogenesis

    PubMed Central

    Madison, Marisa N.; Okeoma, Chioma M.

    2015-01-01

    Exosomes are membranous nanovesicles of endocytic origin that carry host and pathogen derived genomic, proteomic, and lipid cargos. Exosomes are secreted by most cell types into the extracellular milieu and are subsequently internalized by recipient cells. Upon internalization, exosomes condition recipient cells by donating their cargos and/or activating various signal transduction pathways, consequently regulating physiological and pathophysiological processes. The role of exosomes in viral pathogenesis, especially human immunodeficiency virus type 1 [HIV-1] is beginning to unravel. Recent research reports suggest that exosomes from various sources play important but different roles in the pathogenesis of HIV-1. From these reports, it appears that the source of exosomes is the defining factor for the exosomal effect on HIV-1. In this review, we will describe how HIV-1 infection is modulated by exosomes and in turn how exosomes are targeted by HIV-1 factors. Finally, we will discuss potentially emerging therapeutic options based on exosomal cargos that may have promise in preventing HIV-1 transmission. PMID:26205405

  12. Exosomes: Implications in HIV-1 Pathogenesis.

    PubMed

    Madison, Marisa N; Okeoma, Chioma M

    2015-07-20

    Exosomes are membranous nanovesicles of endocytic origin that carry host and pathogen derived genomic, proteomic, and lipid cargos. Exosomes are secreted by most cell types into the extracellular milieu and are subsequently internalized by recipient cells. Upon internalization, exosomes condition recipient cells by donating their cargos and/or activating various signal transduction pathways, consequently regulating physiological and pathophysiological processes. The role of exosomes in viral pathogenesis, especially human immunodeficiency virus type 1 [HIV-1] is beginning to unravel. Recent research reports suggest that exosomes from various sources play important but different roles in the pathogenesis of HIV-1. From these reports, it appears that the source of exosomes is the defining factor for the exosomal effect on HIV-1. In this review, we will describe how HIV-1 infection is modulated by exosomes and in turn how exosomes are targeted by HIV-1 factors. Finally, we will discuss potentially emerging therapeutic options based on exosomal cargos that may have promise in preventing HIV-1 transmission.

  13. HIV-1 transmission linkage in an HIV-1 prevention clinical trial

    SciTech Connect

    Leitner, Thomas; Campbell, Mary S; Mullins, James I; Hughes, James P; Wong, Kim G; Raugi, Dana N; Scrensen, Stefanie

    2009-01-01

    HIV-1 sequencing has been used extensively in epidemiologic and forensic studies to investigate patterns of HIV-1 transmission. However, the criteria for establishing genetic linkage between HIV-1 strains in HIV-1 prevention trials have not been formalized. The Partners in Prevention HSV/HIV Transmission Study (ClinicaITrials.gov NCT00194519) enrolled 3408 HIV-1 serodiscordant heterosexual African couples to determine the efficacy of genital herpes suppression with acyclovir in reducing HIV-1 transmission. The trial analysis required laboratory confirmation of HIV-1 linkage between enrolled partners in couples in which seroconversion occurred. Here we describe the process and results from HIV-1 sequencing studies used to perform transmission linkage determination in this clinical trial. Consensus Sanger sequencing of env (C2-V3-C3) and gag (p17-p24) genes was performed on plasma HIV-1 RNA from both partners within 3 months of seroconversion; env single molecule or pyrosequencing was also performed in some cases. For linkage, we required monophyletic clustering between HIV-1 sequences in the transmitting and seroconverting partners, and developed a Bayesian algorithm using genetic distances to evaluate the posterior probability of linkage of participants sequences. Adjudicators classified transmissions as linked, unlinked, or indeterminate. Among 151 seroconversion events, we found 108 (71.5%) linked, 40 (26.5%) unlinked, and 3 (2.0%) to have indeterminate transmissions. Nine (8.3%) were linked by consensus gag sequencing only and 8 (7.4%) required deep sequencing of env. In this first use of HIV-1 sequencing to establish endpoints in a large clinical trial, more than one-fourth of transmissions were unlinked to the enrolled partner, illustrating the relevance of these methods in the design of future HIV-1 prevention trials in serodiscordant couples. A hierarchy of sequencing techniques, analysis methods, and expert adjudication contributed to the linkage

  14. HIV-1 TAT Inhibits Microglial Phagocytosis of Aβ Peptide

    PubMed Central

    Giunta, Brian; Zhou, Yuyan; Hou, Huayan; Rrapo, Elona; Fernandez, Francisco; Tan, Jun

    2008-01-01

    Human immunodeficiency virus (HIV)-associated dementia (HAD) is a subcortical neuropsychiatric syndrome that has increased in prevalence in the era of highly active antiretroviral therapy (HAART). Several studies demonstrated increased amyloidosis in brains of HIV patients and suggested that there may be a significant number of long-term HIV survivors with co-morbid Alzheimer's disease (AD) in the future. We show HIV-1 Tat protein inhibits microglial uptake of Aβ1-42 peptide, a process that is enhanced by interferon-gamma (IFN-γ) and rescued by the STAT1 inhibitor (-)-epigallocatechin-3-gallate (EGCG). It is hypothesized that reduced Aβ uptake occurs through IFN-γ mediated STAT1 activation. This process promotes a switch from a phagocytic to an antigen presenting phenotype in microglia through activation of class II transactivator (CIITA). Additionally, we show that HIV-1 Tat significantly disrupts apolipoprotein-3 (Apo-E3) promoted microglial Aβ uptake. As Tat has been shown to directly interact with the low density lipoprotein (LRP) receptor and thus inhibit the uptake of its ligands including apolipoprotein E4 (Apo-E4) and Aβ peptide in neurons, we further hypothesize that a similar inhibition of LRP may occur in microglia. Future studies will be required to fully characterize the mechanisms underlying IFN-γ enhancement of HIV-1 Tats disruption of microglial phagocytosis of Aβ and Apo-E3. PMID:18784813

  15. Dendritic Cells from HIV Controllers Have Low Susceptibility to HIV-1 Infection In Vitro but High Capacity to Capture HIV-1 Particles.

    PubMed

    Hamimi, Chiraz; David, Annie; Versmisse, Pierre; Weiss, Laurence; Bruel, Timothée; Zucman, David; Appay, Victor; Moris, Arnaud; Ungeheuer, Marie-Noëlle; Lascoux-Combe, Caroline; Barré-Sinoussi, Françoise; Muller-Trutwin, Michaela; Boufassa, Faroudy; Lambotte, Olivier; Pancino, Gianfranco; Sáez-Cirión, Asier

    2016-01-01

    HIV controllers (HICs), rare HIV-1 infected individuals able to control viral replication without antiretroviral therapy, are characterized by an efficient polyfunctional and cytolytic HIV-specific CD8+ T cell response. The mechanisms underlying the induction and maintenance of such response in many HICs despite controlled viremia are not clear. Dendritic cells play a crucial role in the generation and reactivation of T cell responses but scarce information is available on those cells in HICs. We found that monocyte derived dendritic cells (MDDCs) from HICs are less permissive to HIV-1 infection than cells from healthy donors. In contrast MDDCs from HICs are particularly efficient at capturing HIV-1 particles when compared to cells from healthy donors or HIV-1 patients with suppressed viral load on antiretroviral treatment. MDDCs from HICs expressed on their surface high levels of syndecan-3, DC-SIGN and MMR, which could cooperate to facilitate HIV-1 capture. The combination of low susceptibility to HIV-1 infection but enhanced capacity to capture particles might allow MDDCs from HICs to preserve their function from the deleterious effect of infection while facilitating induction of HIV-specific CD8+ T cells by cross-presentation in a context of low viremia. PMID:27505169

  16. Dendritic Cells from HIV Controllers Have Low Susceptibility to HIV-1 Infection In Vitro but High Capacity to Capture HIV-1 Particles

    PubMed Central

    Hamimi, Chiraz; David, Annie; Versmisse, Pierre; Weiss, Laurence; Bruel, Timothée; Zucman, David; Appay, Victor; Moris, Arnaud; Ungeheuer, Marie-Noëlle; Lascoux-Combe, Caroline; Barré-Sinoussi, Françoise; Muller-Trutwin, Michaela; Boufassa, Faroudy; Lambotte, Olivier; Pancino, Gianfranco; Sáez-Cirión, Asier

    2016-01-01

    HIV controllers (HICs), rare HIV-1 infected individuals able to control viral replication without antiretroviral therapy, are characterized by an efficient polyfunctional and cytolytic HIV-specific CD8+ T cell response. The mechanisms underlying the induction and maintenance of such response in many HICs despite controlled viremia are not clear. Dendritic cells play a crucial role in the generation and reactivation of T cell responses but scarce information is available on those cells in HICs. We found that monocyte derived dendritic cells (MDDCs) from HICs are less permissive to HIV-1 infection than cells from healthy donors. In contrast MDDCs from HICs are particularly efficient at capturing HIV-1 particles when compared to cells from healthy donors or HIV-1 patients with suppressed viral load on antiretroviral treatment. MDDCs from HICs expressed on their surface high levels of syndecan-3, DC-SIGN and MMR, which could cooperate to facilitate HIV-1 capture. The combination of low susceptibility to HIV-1 infection but enhanced capacity to capture particles might allow MDDCs from HICs to preserve their function from the deleterious effect of infection while facilitating induction of HIV-specific CD8+ T cells by cross-presentation in a context of low viremia. PMID:27505169

  17. Exercise and Human Immunodeficiency Virus (HIV-1) Infection

    NASA Technical Reports Server (NTRS)

    Lawless, DeSales; Jackson, Catherine G. R.; Greenleaf, John E.

    1995-01-01

    The human immune system is highly efficient and remarkably protective when functioning properly. Similar to other physiological systems, it functions best when the body is maintained with a balanced diet, sufficient rest and a moderately stress-free lifestyle. It can be disrupted by inappropriate drug use and extreme emotion or exertion. The functioning of normal or compromised immune systems can be enhanced by properly prescribed moderate exercise conditioning regimens in healthy people, and in some human immunodeficiency virus (HIV-1)-infected patients but not in others who unable to complete an interval training program. Regular exercise conditioning in healthy people reduces cardiovascular risk factors, increases stamina, facilitates bodyweight control, and reduces stress by engendering positive feelings of well-being. Certain types of cancer may also be suppressed by appropriate exercise conditioning. Various exercise regimens are being evaluated as adjunct treatments for medicated patients with the HIV-1 syndrome. Limited anecdotal evidence from patients suggests that moderate exercise conditioning is per se responsible for their survival well beyond expectancy. HIV-1-infected patients respond positively, both physiologically and psychologically, to moderate exercise conditioning. However, the effectiveness of any exercise treatment programme depends on its mode, frequency, intensity and duration when prescribed o complement the pathological condition of the patient. The effectiveness of exercise conditioning regimens in patients with HIV-1 infection is reviewed in this article. In addition, we discuss mechanisms and pathways, involving the interplay of psychological and physiological factors, through which the suppressed immune system can be enhanced. The immune modulators discussed are endogenous opioids, cytokines, neurotransmitters and other hormones. Exercise conditioning treatment appears to be more effective when combined with other stress management

  18. High-Throughput Humanized Mouse Models for Evaluation of HIV-1 Therapeutics and Pathogenesis.

    PubMed

    Thomas, Tynisha; Seay, Kieran; Zheng, Jian Hua; Zhang, Cong; Ochsenbauer, Christina; Kappes, John C; Goldstein, Harris

    2016-01-01

    enhance mucosal transmission of HIV-1.

  19. Maturation-Induced Cloaking of Neutralization Epitopes on HIV-1 Particles

    PubMed Central

    Joyner, Amanda S.; Willis, Jordan R.; Crowe, James E.; Aiken, Christopher

    2011-01-01

    To become infectious, HIV-1 particles undergo a maturation process involving proteolytic cleavage of the Gag and Gag-Pol polyproteins. Immature particles contain a highly stable spherical Gag lattice and are impaired for fusion with target cells. The fusion impairment is relieved by truncation of the gp41 cytoplasmic tail (CT), indicating that an interaction between the immature viral core and gp41 within the particle represses HIV-1 fusion by an unknown mechanism. We hypothesized that the conformation of Env on the viral surface is regulated allosterically by interactions with the HIV-1 core during particle maturation. To test this, we quantified the binding of a panel of monoclonal antibodies to mature and immature HIV-1 particles by immunofluorescence imaging. Surprisingly, immature particles exhibited markedly enhanced binding of several gp41-specific antibodies, including two that recognize the membrane proximal external region (MPER) and neutralize diverse HIV-1 strains. Several of the differences in epitope exposure on mature and immature particles were abolished by truncation of the gp41 CT, thus linking the immature HIV-1 fusion defect with altered Env conformation. Our results suggest that perturbation of fusion-dependent Env conformational changes contributes to the impaired fusion of immature particles. Masking of neutralization-sensitive epitopes during particle maturation may contribute to HIV-1 immune evasion and has practical implications for vaccine strategies targeting the gp41 MPER. PMID:21931551

  20. Novel approaches in polyepitope T-cell vaccine development against HIV-1.

    PubMed

    Karpenko, Larisa I; Bazhan, Sergei I; Antonets, Denis V; Belyakov, Igor M

    2014-01-01

    RV144 clinical trial was modestly effective in preventing HIV infection. New alternative approaches are needed to design improved HIV-1 vaccines and their delivery strategies. One of these approaches is construction of synthetic polyepitope HIV-1 immunogen using protective T- and B-cell epitopes that can induce broadly neutralizing antibodies and responses of cytotoxic (CD8(+) CTL) and helpers (CD4(+) Th) T-lymphocytes. This approach seems to be promising for designing of new generation of vaccines against HIV-1, enables in theory to cope with HIV-1 antigenic variability, focuses immune responses on protective determinants and enables to exclude from the vaccine compound that can induce autoantibodies or antibodies enhancing HIV-1 infectivity. Herein, the authors will focus on construction and rational design of polyepitope T-cell HIV-1 immunogens and their delivery, including: advantages and disadvantages of existing T-cell epitope prediction methods; features of organization of polyepitope immunogens, which can generate high-level CD8(+) and CD4(+) T-lymphocyte responses; the strategies to optimize efficient processing, presentation and immunogenicity of polyepitope constructs; original software to design polyepitope immunogens; and delivery vectors as well as mucosal strategies of vaccination. This new knowledge may bring us a one step closer to developing an effective T-cell vaccine against HIV-1, other chronic viral infections and cancer.

  1. The Role of Sexually Transmitted Infections in HIV-1 Progression: A Comprehensive Review of the Literature

    PubMed Central

    Chun, Helen M.; Carpenter, Robert J.; Macalino, Grace E.; Crum-Cianflone, Nancy F.

    2013-01-01

    Due to shared routes of infection, HIV-infected persons are frequently coinfected with other sexually transmitted infections (STIs). Studies have demonstrated the bidirectional relationships between HIV and several STIs, including herpes simplex virus-2 (HSV-2), hepatitis B and C viruses, human papilloma virus, syphilis, gonorrhea, chlamydia, and trichomonas. HIV-1 may affect the clinical presentation, treatment outcome, and progression of STIs, such as syphilis, HSV-2, and hepatitis B and C viruses. Likewise, the presence of an STI may increase both genital and plasma HIV-1 RNA levels, enhancing the transmissibility of HIV-1, with important public health implications. Regarding the effect of STIs on HIV-1 progression, the most studied interrelationship has been with HIV-1/HSV-2 coinfection, with recent studies showing that antiherpetic medications slow the time to CD4 <200 cells/µL and antiretroviral therapy among coinfected patients. The impact of other chronic STIs (hepatitis B and C) on HIV-1 progression requires further study, but some studies have shown increased mortality rates. Treatable, nonchronic STIs (i.e., syphilis, gonorrhea, chlamydia, and trichomonas) typically have no or transient impacts on plasma HIV RNA levels that resolve with antimicrobial therapy; no long-term effects on outcomes have been shown. Future studies are advocated to continue investigating the complex interplay between HIV-1 and other STIs. PMID:26316953

  2. Spermatozoa capture HIV-1 through heparan sulfate and efficiently transmit the virus to dendritic cells

    PubMed Central

    Ceballos, Ana; Remes Lenicov, Federico; Sabatté, Juan; Rodríguez Rodrígues, Christian; Cabrini, Mercedes; Jancic, Carolina; Raiden, Silvina; Donaldson, Mónica; Agustín Pasqualini, Rodolfo; Marin-Briggiler, Clara; Vazquez-Levin, Mónica; Capani, Francisco; Amigorena, Sebastián

    2009-01-01

    Semen is the main vector for HIV-1 dissemination worldwide. It contains three major sources of infectious virus: free virions, infected leukocytes, and spermatozoa-associated virions. We focused on the interaction of HIV-1 with human spermatozoa and dendritic cells (DCs). We report that heparan sulfate is expressed in spermatozoa and plays an important role in the capture of HIV-1. Spermatozoa-attached virus is efficiently transmitted to DCs, macrophages, and T cells. Interaction of spermatozoa with DCs not only leads to the transmission of HIV-1 and the internalization of the spermatozoa but also results in the phenotypic maturation of DCs and the production of IL-10 but not IL-12p70. At low values of extracellular pH (∼6.5 pH units), similar to those found in the vaginal mucosa after sexual intercourse, the binding of HIV-1 to the spermatozoa and the consequent transmission of HIV-1 to DCs were strongly enhanced. Our observations support the notion that far from being a passive carrier, spermatozoa acting in concert with DCs might affect the early course of sexual transmission of HIV-1 infection. PMID:19858326

  3. IL-1β and IL-18 inhibition of HIV-1 replication in Jurkat cells and PBMCs.

    PubMed

    Wang, Xue; Mbondji-Wonje, Christelle; Zhao, Jiangqin; Hewlett, Indira

    2016-05-13

    HIV-1 infection-induced apoptosis is able to ensure viral replication. The death of some CD4+ T cells residing in lymphoid tissues can be induced by HIV-1 infection through caspase-1 driven pyroptosis with release of cytokine of IL-1β and IL-18. It is not well known whether IL-1β and IL-18 affect HIV-1 replication in lymphocytic cells. Using susceptible lymphocytic cell line, Jurkat cells, and primary peripheral blood mononuclear cells (PBMCs), we studied the effects of IL-1β and IL-18 on HIV-1 replication. We found that treatment with exogenous IL-1β protein (rIL-1β) and IL-18 protein (rIL-18), or expression of IL-1β and IL-18 significantly reduced HIV-1 replication. HIV-1 infection enhanced caspase-3 expression and its activation, and had no effects on caspase-1 activity. Treatment with rIL-1β and rIL-18 dramatically lowered caspase-3 activity. IL-1β and IL-18 also played roles in diminishing reactivation of viral replication from latency in J1.1 cells. These results indicate that IL-1β and IL-18 are able to inhibit HIV-1 replication, and their effects may be due to signaling through apoptosis involved in inactivation of caspase-3 activity.

  4. HIV-1 infection in Juba, southern Sudan.

    PubMed

    McCarthy, M C; Khalid, I O; El Tigani, A

    1995-05-01

    Thirty years of civil war in the Sudan have resulted in the isolation of the southern provinces which border Central and East Africa. Consequently, little is known about the epidemiology of HIV-1 infection in this region. To estimate the prevalence of HIV-1 infection in southern Sudan and the risk factors associated with disease transmission, a seroepidemiologic survey was conducted in the township of Juba. Study subjects invited to participate in this study included medical outpatients, inpatients hospitalized for active tuberculosis, and female prostitutes. A total of 401 subjects participated in the study. HIV-1 infection was confirmed in 25 subjects. The prevalence of HIV-1 infection was 19% (8/42) among tuberculosis patients, 16% (8/50) among prostitutes, and 3% (9/309) among outpatients. A significantly higher prevalence of HIV-1 infection was found among female prostitutes when compared to female outpatients: 16% (8/50) vs. 2% (4/178), P < 0.001. Correspondingly, the prevalence of seropositives was significantly higher among male outpatients reporting a history of sexual relations with prostitutes during the prior 10 years compared to male outpatients denying relations with prostitutes: 14% (5/37) vs. 0% (0/94), P = 0.0011. A history of a sexually transmitted disease (STD) was also associated with HIV-1 infection among male outpatients. The findings of this study indicate that HIV-1 infection is highly prevalent in southern Sudan and that prostitutes and their sexual partners represent a major reservoir of HIV infection in this population. This epidemiologic pattern resembles that seen in the African nations neighboring southern Sudan.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Envelope gene evolution and HIV-1 neuropathogenesis

    PubMed Central

    Vázquez-Santiago, Fabián J.; Rivera-Amill, Vanessa

    2016-01-01

    In the era of combined antiretroviral therapy (cART), HIV-associated neurocognitive disorders (HAND) account for 40 to 56% of all HIV+ cases. During the acute stage of HIV-1 infection (<6 months), the virus invades and replicates within the central nervous system (CNS). Compared to peripheral tissues, the local CNS cell population expresses distinct levels of chemokine receptors, which levels exert selective pressure on the invading virus. HIV-1 envelope (env) sequences recovered from the brains and cerebrospinal fluid (CSF) of neurocognitively impaired HIV+ subjects often display higher nucleotide variability as compared to non-impaired HIV+ subjects. Specifically, env evolution provides HIV-1 with the strategies to evade host immune response, to reduce chemokine receptor dependence, to increase co-receptor binding efficiency, and to potentiate neurotoxicity. The evolution of env within the CNS leads to changes that may result in the emergence of novel isolates with neurotoxic and neurovirulent features. However, whether specific factors of HIV-1 evolution lead to the emergence of neurovirulent and neurotropic isolates remains ill-defined. HIV-1 env evolution is an ongoing phenomenon that occurs independently of neurological and neurocognitive disease severity; thus HIV env evolution may play a pivotal and reciprocal role in the etiology of HAND. Despite the use of cART, the reactivation of latent viral reservoirs represents a clinical challenge because of the replenishment of the viral pool that may subsequently lead to persistent infection. Therefore, gaining a more complete understanding of how HIV-1 env evolves over the course of the disease should be considered for the development of future therapies aimed at controlling CNS burden, diminishing persistent viremia, and eradicating viral reservoirs. Here we review the current literature on the role of HIV-1 env evolution in the setting of HAND disease progression and on the impact of cART on the dynamics of

  6. Abrogation of contaminating RNA activity in HIV-1 Gag VLPs

    PubMed Central

    2011-01-01

    Background HIV-1 Gag virus like particles (VLPs) used as candidate vaccines are regarded as inert particles as they contain no replicative nucleic acid, although they do encapsidate cellular RNAs. During HIV-1 Gag VLP production in baculovirus-based expression systems, VLPs incorporate the baculovirus Gp64 envelope glycoprotein, which facilitates their entry into mammalian cells. This suggests that HIV-1 Gag VLPs produced using this system facilitate uptake and subsequent expression of encapsidated RNA in mammalian cells - an unfavourable characteristic for a vaccine. Methods HIV-1 Gag VLPs encapsidating reporter chloramphenicol acetyl transferase (CAT) RNA, were made in insect cells using the baculovirus expression system. The presence of Gp64 on the VLPs was verified by western blotting and RT-PCR used to detect and quantitate encapsidated CAT RNA. VLP samples were heated to inactivate CAT RNA. Unheated and heated VLPs incubated with selected mammalian cell lines and cell lysates tested for the presence of CAT protein by ELISA. Mice were inoculated with heated and unheated VLPs using a DNA prime VLP boost regimen. Results HIV-1 Gag VLPs produced had significantly high levels of Gp64 (~1650 Gp64 molecules/VLP) on their surfaces. The amount of encapsidated CAT RNA/μg Gag VLPs ranged between 0.1 to 7 ng. CAT protein was detected in 3 of the 4 mammalian cell lines incubated with VLPs. Incubation with heated VLPs resulted in BHK-21 and HeLa cell lysates showing reduced CAT protein levels compared with unheated VLPs and HEK-293 cells. Mice inoculated with a DNA prime VLP boost regimen developed Gag CD8 and CD4 T cell responses to GagCAT VLPs which also boosted a primary DNA response. Heating VLPs did not abrogate these immune responses but enhanced the Gag CD4 T cell responses by two-fold. Conclusions Baculovirus-produced HIV-1 Gag VLPs encapsidating CAT RNA were taken up by selected mammalian cell lines. The presence of CAT protein indicates that encapsidated RNA was

  7. Altered Dendritic Cell Phenotype in Response to Leishmania amazonensis Amastigote Infection Is Mediated by MAP Kinase, ERK

    PubMed Central

    Boggiatto, Paola Mercedes; Jie, Fei; Ghosh, Mousumi; Gibson-Corley, Katherine Nicole; Ramer-Tait, Amanda Ellen; Jones, Douglas Elliot; Petersen, Christine Anne

    2009-01-01

    Initiation of productive immune responses against Leishmania depends on the successful transition of dendritic cells (DC) from an immature to a mature phenotype. This process is characterized by high CD40 surface expression as well as interleukin-12 production, which are frequently seen in response to L. major infection. In vivo footpad infection of C3HeB/FeJ mice for 7 days with L. amazonensis promoted an immature CD11c+ DC phenotype characterized by both significantly low CD40 surface expression and significantly decreased interleukin-12p40 production compared with L. major infection of these same mice. In vitro infection of bone marrow-derived dendritic cells with L. amazonensis amastigotes resulted in rapid and significant phosphorylation of the mitogen activated protein kinase, extracellular signal-regulated kinase 1/2, observed within minutes of exposure to the parasite. Infection with L. amazonensis promastigotes led to increased 1/2 phosphorylation after 4 hours of infection compared with L. major infection, which correlated with promastigote transformation into amastigotes. Treatment of bone marrow-derived dendritic cells with a mitogen activated protein kinase kinase-specific inhibitor, PD98059, led to regained surface CD40 expression and interleukin-12p40 production following L. amazonensis amastigote infection compared with non-treated, infected DC. Treatment of L. amazonensis-infected mice with the highly-specific mitogen activated protein kinase kinase inhibitor, CI-1040, enhanced surface CD40 expression on CD11c+ DC obtained from the draining lymph node. L. amazonensis amastigotes, through activation of extracellular signal-regulated kinase 1/2, inhibit the ability of DC to undergo proper maturation both in vitro and in vivo. PMID:19349356

  8. SERINC3 and SERINC5 restrict HIV-1 infectivity and are counteracted by Nef

    PubMed Central

    Usami, Yoshiko; Wu, Yuanfei; Göttlinger, Heinrich G.

    2015-01-01

    HIV-1 Nef and the unrelated murine leukemia virus glycoGag strongly enhance the infectivity of HIV-1 virions produced in certain cell types in a clathrin-dependent manner. Here we show that Nef and glycoGag prevent the incorporation of the multipass transmembrane proteins SERINC3 and SERINC5 into HIV-1 virions to an extent that correlates with infectivity enhancement. Silencing of SERINC3 together with SERINC5 precisely phenocopied the effects of Nef and glycoGag on HIV-1 infectivities. The infectivity of nef-deficient virions increased more than 100-fold when produced in double-knockout human CD4+ T cells that lack both SERINC3 and SERINC5, and re-expression experiments confirmed that the absence of SERINC3 and SERINC5 accounted for the infectivity enhancement. Furthermore, SERINC3 and SERINC5 together restricted HIV-1 replication, and this restriction was evaded by Nef. SERINC3 and SERINC5 are highly expressed in primary human HIV-1 target cells, and inhibiting their downregulation by Nef is a potential strategy to combat HIV/AIDS. PMID:26416733

  9. N6-methyladenosine of HIV-1 RNA regulates viral infection and HIV-1 Gag protein expression

    PubMed Central

    Tirumuru, Nagaraja; Zhao, Boxuan Simen; Lu, Wuxun; Lu, Zhike; He, Chuan; Wu, Li

    2016-01-01

    The internal N6-methyladenosine (m6A) methylation of eukaryotic nuclear RNA controls post-transcriptional gene expression, which is regulated by methyltransferases (writers), demethylases (erasers), and m6A-binding proteins (readers) in cells. The YTH domain family proteins (YTHDF1–3) bind to m6A-modified cellular RNAs and affect RNA metabolism and processing. Here, we show that YTHDF1–3 proteins recognize m6A-modified HIV-1 RNA and inhibit HIV-1 infection in cell lines and primary CD4+ T-cells. We further mapped the YTHDF1–3 binding sites in HIV-1 RNA from infected cells. We found that the overexpression of YTHDF proteins in cells inhibited HIV-1 infection mainly by decreasing HIV-1 reverse transcription, while knockdown of YTHDF1–3 in cells had the opposite effects. Moreover, silencing the m6A writers decreased HIV-1 Gag protein expression in virus-producing cells, while silencing the m6A erasers increased Gag expression. Our findings suggest an important role of m6A modification of HIV-1 RNA in viral infection and HIV-1 protein synthesis. DOI: http://dx.doi.org/10.7554/eLife.15528.001 PMID:27371828

  10. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules

    PubMed Central

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S. Y.

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This “shock” approach is then followed by “kill” of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells. PMID:27049645

  11. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules.

    PubMed

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S Y

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells.

  12. N(6)-methyladenosine of HIV-1 RNA regulates viral infection and HIV-1 Gag protein expression.

    PubMed

    Tirumuru, Nagaraja; Zhao, Boxuan Simen; Lu, Wuxun; Lu, Zhike; He, Chuan; Wu, Li

    2016-01-01

    The internal N(6)-methyladenosine (m(6)A) methylation of eukaryotic nuclear RNA controls post-transcriptional gene expression, which is regulated by methyltransferases (writers), demethylases (erasers), and m(6)A-binding proteins (readers) in cells. The YTH domain family proteins (YTHDF1-3) bind to m(6)A-modified cellular RNAs and affect RNA metabolism and processing. Here, we show that YTHDF1-3 proteins recognize m(6)A-modified HIV-1 RNA and inhibit HIV-1 infection in cell lines and primary CD4(+) T-cells. We further mapped the YTHDF1-3 binding sites in HIV-1 RNA from infected cells. We found that the overexpression of YTHDF proteins in cells inhibited HIV-1 infection mainly by decreasing HIV-1 reverse transcription, while knockdown of YTHDF1-3 in cells had the opposite effects. Moreover, silencing the m(6)A writers decreased HIV-1 Gag protein expression in virus-producing cells, while silencing the m(6)A erasers increased Gag expression. Our findings suggest an important role of m(6)A modification of HIV-1 RNA in viral infection and HIV-1 protein synthesis. PMID:27371828

  13. Specific Elimination of Latently HIV-1 Infected Cells Using HIV-1 Protease-Sensitive Toxin Nanocapsules.

    PubMed

    Wen, Jing; Yan, Ming; Liu, Yang; Li, Jie; Xie, Yiming; Lu, Yunfeng; Kamata, Masakazu; Chen, Irvin S Y

    2016-01-01

    Anti-retroviral drugs suppress HIV-1 plasma viremia to undetectable levels; however, latent HIV-1 persists in reservoirs within HIV-1-infected patients. The silent provirus can be activated through the use of drugs, including protein kinase C activators and histone deacetylase inhibitors. This "shock" approach is then followed by "kill" of the producing cells either through direct HIV-1-induced cell death or natural immune mechanisms. However, these mechanisms are relatively slow and effectiveness is unclear. Here, we develop an approach to specifically target and kill cells that are activated early in the process of virus production. We utilize a novel nanocapsule technology whereby the ricin A chain is encapsulated in an inactive form within a polymer shell. Specificity for release of the ricin A toxin is conferred by peptide crosslinkers that are sensitive to cleavage by HIV-1 protease. By using well-established latent infection models, J-Lat and U1 cells, we demonstrate that only within an HIV-1-producing cell expressing functional HIV-1 protease will the nanocapsule release its ricin A cargo, shutting down viral and cellular protein synthesis, and ultimately leading to rapid death of the producer cell. Thus, we provide proof of principle for a novel technology to kill HIV-1-producing cells without effects on non-target cells. PMID:27049645

  14. HIV-1 Genetic Variability and Clinical Implications

    PubMed Central

    Santoro, Maria Mercedes; Perno, Carlo Federico

    2013-01-01

    Despite advances in antiretroviral therapy that have revolutionized HIV disease management, effective control of the HIV infection pandemic remains elusive. Beyond the classic non-B endemic areas, HIV-1 non-B subtype infections are sharply increasing in previous subtype B homogeneous areas such as Europe and North America. As already known, several studies have shown that, among non-B subtypes, subtypes C and D were found to be more aggressive in terms of disease progression. Luckily, the response to antiretrovirals against HIV-1 seems to be similar among different subtypes, but these results are mainly based on small or poorly designed studies. On the other hand, differences in rates of acquisition of resistance among non-B subtypes are already being observed. This different propensity, beyond the type of treatment regimens used, as well as access to viral load testing in non-B endemic areas seems to be due to HIV-1 clade specific peculiarities. Indeed, some non-B subtypes are proved to be more prone to develop resistance compared to B subtype. This phenomenon can be related to the presence of subtype-specific polymorphisms, different codon usage, and/or subtype-specific RNA templates. This review aims to provide a complete picture of HIV-1 genetic diversity and its implications for HIV-1 disease spread, effectiveness of therapies, and drug resistance development. PMID:23844315

  15. The hunt for HIV-1 integrase inhibitors.

    PubMed

    Lataillade, Max; Kozal, Michael J

    2006-07-01

    Currently, there are three distinct mechanistic classes of antiretrovirals: inhibitors of the HIV- 1 reverse transcriptase and protease enzymes and inhibitors of HIV entry, including receptor and coreceptor binding and cell fusion. A new drug class that inhibits the HIV-1 integrase enzyme (IN) is in development and may soon be available in the clinic. IN is an attractive drug target because it is essential for a stable and productive HIV-1 infection and there is no mammalian homologue of IN. Inhibitors of integrase enzyme (INI) block the integration of viral double-stranded DNA into the host cell's chromosomal DNA. HIV-1 integration has many potential steps that can be inhibited and several new compounds that target specific integration steps have been identified by drug developers. Recently, two INIs, GS-9137 and MK-0518, demonstrated promising early clinical trial results and have been advanced into later stage trials. In this review, we describe how IN facilitates HIV-1 integration, the needed enzyme cofactors, and the resultant byproducts created during integration. Furthermore, we review the different INIs under development, their mechanism of actions, site of IN inhibition, potency, resistance patterns, and discuss the early clinical trial results.

  16. Restriction Factors in HIV-1 Disease Progression.

    PubMed

    Merindol, Natacha; Berthoux, Lionel

    2015-01-01

    About 35 million people worldwide were living with HIV-1 at the end of 2013 and over 25 million have already died of AIDS. AIDS patients show high variability in the speed of disease progression in the absence of treatment. While certain immunological traits have been shown to correlate with accelerated or slowed progression in some subjects, including slow progressors, factors controlling HIV-1 replication and disease kinetics remain largely enigmatic. The importance of T lymphocytes and of protective HLA-alleles is undeniable, but not sufficient to explain every attenuated phenotype. A thorough understanding of HIV-1 infection control in these patient subsets may help the development of novel strategies for treatment and prevention. Restriction factors are type I interferon-induced specialized cellular proteins that block viruses at different steps of their life cycle. TRIM5α, Mx2/MxB, TRIM22/Staf50, SAMHD1, p21/CDKN1, tetherin/BST2/CD137, APOBEC3G and APOBEC3F have all been proposed to inhibit HIV-1, often with gene variant- or cellular context-specificity. Recent evidence highlights their possible implication in AIDS disease progression. In this review, we depict their restrictive activity against HIV-1 and recapitulate the latest data on their potential role in vivo, in both normal and slow progressors.

  17. Recent Progress toward Engineering HIV-1-Specific Neutralizing Monoclonal Antibodies

    PubMed Central

    Sun, Ming; Li, Yue; Zheng, Huiwen; Shao, Yiming

    2016-01-01

    The recent discoveries of broadly potent neutralizing human monoclonal antibodies represent a new generation of antiretrovirals for the treatment and prophylaxis. Antibodies are generally considered more effective and safer and have been proved to provide passive protection against mucosal challenge in humanized mice and macaques. Several neutralizing Abs could protect animals against HIV-1 but are not effective when used in an established infected model for therapy. In order to overcome the limitation of antiviral activities, multiple antibody-engineering technologies have been explored to generate “the better” neutralizing antibodies against HIV-1 since bNAbs attack viral entry by various mechanisms. Thus, a promising direction of research is to discover and exploit rational antibody combination or engineered antibodies (eAbs) as potential candidate therapeutics against HIV-1. It has been reported that inclusion of fusion-neutralizing antibodies in a set of bNAbs could improve their overall activities and neutralizing spectrum. Here, we review several routes for engineering bNAbs, such as design and generation of bispecific antibodies, specific glycosylation of antibodies to enhance antiviral activity, and variable region-specific modification guided by structure and computer, as well as reviewing antibody-delivery technologies by non-viral vector, viral vector, and human hematopoietic stem/progenitor cells transduced with a lentiviral construct. We also discuss the optimized antiviral activities and benefits of these strategy and potential mechanisms. PMID:27746780

  18. Blocking of integrins inhibits HIV-1 infection of human cervical mucosa immune cells with free and complement-opsonized virions

    PubMed Central

    Tjomsland, Veronica; Ellegård, Rada; Kjölhede, Preben; Wodlin, Ninni Borendal; Hinkula, Jorma; Lifson, Jeffrey D; Larsson, Marie

    2013-01-01

    The initial interaction between HIV-1 and the host occurs at the mucosa during sexual intercourse. In cervical mucosa, HIV-1 exists both as free and opsonized virions and this might influence initial infection. We used cervical explants to study HIV-1 transmission, the effects of opsonization on infectivity, and how infection can be prevented. Complement opsonization enhanced HIV-1 infection of dendritic cells (DCs) compared with that by free HIV-1, but this increased infection was not observed with CD4+ T cells. Blockage of the α4-, β7-, and β1-integrins significantly inhibited HIV-1 infection of both DCs and CD4+ T cells. We found a greater impairment of HIV-1 infection in DCs for complement-opsonized virions compared with that of free virions when αM/β2- and α4-integrins were blocked. Blocking the C-type lectin receptor macrophage mannose receptor (MMR) inhibited infection of emigrating DCs but had no effect on CD4+ T-cell infection. We show that blocking of integrins decreases the HIV-1 infection of both mucosal DCs and CD4+ T cells emigrating from the cervical tissues. These findings may provide the basis of novel microbicidal strategies that may help limit or prevent initial infection of the cervical mucosa, thereby reducing or averting systemic HIV-1 infection. PMID:23686382

  19. Identification of cellular factors binding to acetylated HIV-1 integrase.

    PubMed

    Allouch, Awatef; Cereseto, Anna

    2011-11-01

    The viral protein integrase (IN) catalyzes the integration of the HIV-1 cDNA into the host cellular genome. We have recently demonstrated that IN is acetylated by a cellular histone acetyltransferase, p300, which modifies three lysines located in the C-terminus of the viral factor (Cereseto et al. in EMBO J 24:3070-3081, 2005). This modification enhances IN catalytic activity, as demonstrated by in vitro assays. Consistently, mutations introduced in the targeted lysines greatly decrease the efficiency of HIV-1 integration. Acetylation was proven to regulate protein functions by modulating protein-protein interactions. HIV-1 to efficiently complete its replication steps, including the integration reaction, requires interacting with numerous cellular factors. Therefore, we sought to investigate whether acetylation might modulate the interaction between IN and the cellular factors. To this aim we performed a yeast two-hybrid screening that differs from the screenings so far performed (Rain et al. in Methods 47:291-297, 2009; Studamire and Goff in Retrovirology 5:48, 2008) for using as bait IN constitutively acetylated. From this analysis we have identified thirteen cellular factors involved in transcription, chromatin remodeling, nuclear transport, RNA binding, protein synthesis regulation and microtubule organization. To validate these interactions, binding assays were performed showing that acetylation increases the affinity of IN with specific factors. Nevertheless, few two-hybrid hits bind with the same affinity the acetylated and the unmodified IN. These results further underlie the relevance of IN post-translational modification by acetylation in HIV-1 replication cycle.

  20. Drug-Induced Reactivation of Apoptosis Abrogates HIV-1 Infection

    PubMed Central

    Hanauske-Abel, Hartmut M.; Saxena, Deepti; Palumbo, Paul E.; Hanauske, Axel-Rainer; Luchessi, Augusto D.; Cambiaghi, Tavane D.; Hoque, Mainul; Spino, Michael; Gandolfi, Darlene D'Alliessi; Heller, Debra S.; Singh, Sukhwinder; Park, Myung Hee; Cracchiolo, Bernadette M.; Tricta, Fernando; Connelly, John; Popowicz, Anthony M.; Cone, Richard A.; Holland, Bart; Pe’ery, Tsafi; Mathews, Michael B.

    2013-01-01

    HIV-1 blocks apoptosis, programmed cell death, an innate defense of cells against viral invasion. However, apoptosis can be selectively reactivated in HIV-infected cells by chemical agents that interfere with HIV-1 gene expression. We studied two globally used medicines, the topical antifungal ciclopirox and the iron chelator deferiprone, for their effect on apoptosis in HIV-infected H9 cells and in peripheral blood mononuclear cells infected with clinical HIV-1 isolates. Both medicines activated apoptosis preferentially in HIV-infected cells, suggesting that the drugs mediate escape from the viral suppression of defensive apoptosis. In infected H9 cells, ciclopirox and deferiprone enhanced mitochondrial membrane depolarization, initiating the intrinsic pathway of apoptosis to execution, as evidenced by caspase-3 activation, poly(ADP-ribose) polymerase proteolysis, DNA degradation, and apoptotic cell morphology. In isolate-infected peripheral blood mononuclear cells, ciclopirox collapsed HIV-1 production to the limit of viral protein and RNA detection. Despite prolonged monotherapy, ciclopirox did not elicit breakthrough. No viral re-emergence was observed even 12 weeks after drug cessation, suggesting elimination of the proviral reservoir. Tests in mice predictive for cytotoxicity to human epithelia did not detect tissue damage or activation of apoptosis at a ciclopirox concentration that exceeded by orders of magnitude the concentration causing death of infected cells. We infer that ciclopirox and deferiprone act via therapeutic reclamation of apoptotic proficiency (TRAP) in HIV-infected cells and trigger their preferential elimination. Perturbations in viral protein expression suggest that the antiretroviral activity of both drugs stems from their ability to inhibit hydroxylation of cellular proteins essential for apoptosis and for viral infection, exemplified by eIF5A. Our findings identify ciclopirox and deferiprone as prototypes of selectively cytocidal

  1. Population genomics of intrapatient HIV-1 evolution.

    PubMed

    Zanini, Fabio; Brodin, Johanna; Thebo, Lina; Lanz, Christa; Bratt, Göran; Albert, Jan; Neher, Richard A

    2015-01-01

    Many microbial populations rapidly adapt to changing environments with multiple variants competing for survival. To quantify such complex evolutionary dynamics in vivo, time resolved and genome wide data including rare variants are essential. We performed whole-genome deep sequencing of HIV-1 populations in 9 untreated patients, with 6-12 longitudinal samples per patient spanning 5-8 years of infection. The data can be accessed and explored via an interactive web application. We show that patterns of minor diversity are reproducible between patients and mirror global HIV-1 diversity, suggesting a universal landscape of fitness costs that control diversity. Reversions towards the ancestral HIV-1 sequence are observed throughout infection and account for almost one third of all sequence changes. Reversion rates depend strongly on conservation. Frequent recombination limits linkage disequilibrium to about 100 bp in most of the genome, but strong hitch-hiking due to short range linkage limits diversity. PMID:26652000

  2. Assessment of mucosal immunity to HIV-1.

    PubMed

    Jespers, Vicky; Harandi, Ali M; Hinkula, Jorma; Medaglini, Donata; Le Grand, Roger; Stahl-Hennig, Christiane; Bogers, Willy; El Habib, Raphaelle; Wegmann, Frank; Fraser, Carol; Cranage, Martin; Shattock, Robin J; Spetz, Anna-Lena

    2010-04-01

    A key gap in the development and evaluation of HIV-1 vaccines is insufficient knowledge with regard to sampling techniques and assessment of mucosal immune responses required for early prevention and inhibition of viral dissemination. In an attempt to start bridging this gap, the EUROPRISE network of scientists working on HIV-1 vaccine and microbicide research organized a workshop with the aim to review the types of mucosal responses/biomarkers currently measured in mucosal immunology and to define how the mucosal responses/biomarkers are measured and/or the assays and sampling methods used. The Workshop addressed two critical questions: first whether, with current knowledge, it would be possible to define a consensus set of mucosal sampling methods to facilitate cross-species comparisons and ensure standardized implementation in clinical trials; second to determine the remaining challenges (technical and logistical) and their possible solutions for assessing mucosal responses to HIV-1 vaccines. PMID:20370549

  3. Population genomics of intrapatient HIV-1 evolution.

    PubMed

    Zanini, Fabio; Brodin, Johanna; Thebo, Lina; Lanz, Christa; Bratt, Göran; Albert, Jan; Neher, Richard A

    2015-01-01

    Many microbial populations rapidly adapt to changing environments with multiple variants competing for survival. To quantify such complex evolutionary dynamics in vivo, time resolved and genome wide data including rare variants are essential. We performed whole-genome deep sequencing of HIV-1 populations in 9 untreated patients, with 6-12 longitudinal samples per patient spanning 5-8 years of infection. The data can be accessed and explored via an interactive web application. We show that patterns of minor diversity are reproducible between patients and mirror global HIV-1 diversity, suggesting a universal landscape of fitness costs that control diversity. Reversions towards the ancestral HIV-1 sequence are observed throughout infection and account for almost one third of all sequence changes. Reversion rates depend strongly on conservation. Frequent recombination limits linkage disequilibrium to about 100 bp in most of the genome, but strong hitch-hiking due to short range linkage limits diversity.

  4. The HIV-1 Protein Vpr Targets the Endoribonuclease Dicer for Proteasomal Degradation to Boost Macrophage Infection

    PubMed Central

    Klockow, Laurieann Casey; Sharifi, Hamayun J.; Wen, Xiaoyun; Flagg, Meg; Furuya, Andrea K. M.; Nekorchuk, Michael; de Noronha, Carlos M.

    2013-01-01

    The HIV-1 protein Vpr enhances macrophage infection, triggers G2 cell cycle arrest, and targets cells for NK-cell killing. Vpr acts through the CRL4DCAF1 ubiquitin ligase complex to cause G2 arrest and trigger expression of NK ligands. Corresponding ubiquitination targets have not been identified. UNG2 and SMUG1 are the only known substrates for Vpr-directed depletion through CRL4DCAF1. Here we identify the endoribonuclease Dicer as a target of HIV-1 Vpr-directed proteasomal degradation through CRL4DCAF1. We show that HIV-1 Vpr inhibits short hairpin RNA function as expected upon reduction of Dicer levels. Dicer inhibits HIV-1 replication in T cells. We demonstrate that Dicer also restricts HIV-1 replication in human monocyte-derived macrophages (MDM) and that reducing Dicer expression in MDMs enhances HIV-1 infection in a Vpr-dependent manner. Our results support a model in which Vpr complexes with human Dicer to boost its interaction with the CRL4DCAF1 ubiquitin ligase complex and its subsequent degradation. PMID:23849790

  5. MAS NMR of HIV-1 protein assemblies

    NASA Astrophysics Data System (ADS)

    Suiter, Christopher L.; Quinn, Caitlin M.; Lu, Manman; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-04-01

    The negative global impact of the AIDS pandemic is well known. In this perspective article, the utility of magic angle spinning (MAS) NMR spectroscopy to answer pressing questions related to the structure and dynamics of HIV-1 protein assemblies is examined. In recent years, MAS NMR has undergone major technological developments enabling studies of large viral assemblies. We discuss some of these evolving methods and technologies and provide a perspective on the current state of MAS NMR as applied to the investigations into structure and dynamics of HIV-1 assemblies of CA capsid protein and of Gag maturation intermediates.

  6. Novel vaccine vectors for HIV-1

    PubMed Central

    Picker, Louis J.

    2014-01-01

    The ultimate solution to the global HIV-1 epidemic will probably require the development of a safe and effective vaccine. Multiple vaccine platforms have been evaluated in both preclinical and clinical trials, but, given the disappointing results of the clinical efficacy studies so far, novel vaccine approaches are needed. In this Opinion article, we discuss the scientific basis and clinical potential of novel adenovirus and cytomegalovirus vaccine vectors for HIV-1 as two contrasting, but potentially complementary, vector approaches. Both of these vector platforms have demonstrated partial protection against stringent simian immunodeficiency virus challenges in rhesus monkeys using different immunological mechanisms. PMID:25296195

  7. HIV-1 Protease: Structure, Dynamics and Inhibition

    SciTech Connect

    Louis, John M.; Ishima, R.; Torchia, D.A.; Weber, Irene T.

    2008-06-03

    The HIV-1 protease is synthesized as part of a large Gag-Pol precursor protein. It is responsible for its own release from the precursor and the processing of the Gag and Gag-Pol polyproteins into the mature structural and functional proteins required for virus maturation. Because of its indispensable role, the mature HIV-1 protease dimer has proven to be a successful target for the development of antiviral agents. In the last 5 years, a major emphasis in protease research has been to improve inhibitor design and treatment regimens.

  8. HIV-1 Suppressive Sequences Are Modulated by Rev Transport of Unspliced RNA and Are Required for Efficient HIV-1 Production

    PubMed Central

    Noguchi, Kousei; Ishibashi, Keisuke; Miyokawa, Kaori; Hokari, Manami; Kanno, Tomoyuki; Hirano, Tomoya; Yamamoto, Norio; Takaku, Hiroshi

    2012-01-01

    The unspliced human immunodeficiency virus type 1 (HIV-1) RNAs are translated as Gag and Gag-Pol polyproteins or packaged as genomes into viral particles. Efficient translation is necessary before the transition to produce infective virions. The viral protein Rev exports all intron-containing viral RNAs; however, it also appears to enhance translation. Cellular microRNAs target cellular and viral mRNAs to silence their translation and enrich them at discrete cytoplasmic loci that overlap with the putative interim site of Gag and the genome. Here, we analyzed how Rev-mediated transport and the splicing status of the mRNA influenced the silencing status imposed by microRNA. Through identification and mutational analysis of the silencing sites in the HIV-1 genome, we elucidated the effect of silencing on virus production. Renilla luciferase mRNA, which contains a let-7 targeting site in its 3′ untranslated region, was mediated when it was transported by Rev and not spliced, but it was either not mediated when it was spliced even in a partial way or it was Rev-independent. The silencing sites in the pol and env-nef regions of the HIV-1 genome, which were repressed in T cells and other cell lines, were Drosha-dependent and could also be modulated by Rev in an unspliced state. Mutant viruses that contained genomic mutations that reflect alterations to show more derepressive effects in the 3′ untranslated region of the Renilla luciferase gene replicated more slowly than wild-type virus. These findings yield insights into the HIV-1 silencing sites that might allow the genome to avoid translational machinery and that might be utilized in coordinating virus production during initial virus replication. However, the function of Rev to modulate the silencing sites of unspliced RNAs would be advantageous for the efficient translation that is required to support protein production prior to viral packaging and particle production. PMID:23251516

  9. Cobalamin inhibition of HIV-1 integrase and integration of HIV-1 DNA into cellular DNA.

    PubMed

    Weinberg, J B; Shugars, D C; Sherman, P A; Sauls, D L; Fyfe, J A

    1998-05-19

    Our prior studies showed that certain cobalamins inhibit productive HIV-1 infection of primary cultures of blood lymphocytes and monocytes. We demonstrate here that this antiviral activity may be mediated by an inhibition of HIV-1 integrase, an enzyme required for productive infection. Purified recombinant HIV-1 integrase activity was inhibited in vitro by hydroxocobalamin (OH-Cbl), methylcobalamin (Me-Cbl), adenosylcobalamin (Ado-Cbl), and dicyanocobinamide (CN2-Cbi) with IC50 values of approximately 17, 17, 17, and 4 microM, respectively. The agents inhibited HIV-1 infection of cultured monocytes (IC50 values for OH-Cbl, Me-Cbl, Ado-Cbl, and CN2-Cbi of 6, 7, 4, and 1 microM, respectively) and of cultured lymphocytes (IC50 values of 60, 50, 60, and 11 microM, respectively). Experiments using cultured monocytes or lymphocytes demonstrated that OH-Cbl inhibited integration of HIV-1 DNA into cellular DNA. Thus, cobalamins and cobinamides represent novel inhibitors of HIV-1 integrase. These or related agents may be useful as anti-viral treatments that target HIV-1 integrase. PMID:9610370

  10. Interaction of the phospholipid scramblase 1 with HIV-1 Tat results in the repression of Tat-dependent transcription

    SciTech Connect

    Kusano, Shuichi Eizuru, Yoshito

    2013-04-19

    Highlights: •PLSCR1 specifically interacted with HIV-1 Tat in vitro and in vivo. •PLSCR1 repressed Tat-dependent transactivation of the HIV-1 LTR. •Suppression of PLSCR1 expression enhanced the levels of HIV-1 transcripts. •PLSCR1 reduced the nuclear localization of Tat. -- Abstract: Human phospholipid scramblase 1 (PLSCR1) is an interferon (IFN)-stimulated gene and possesses an IFN-mediated antiviral function. We show here that PLSCR1 directly interacts with human immunodeficiency virus type-1 (HIV-1) Tat. This interaction occurs both in vitro and in vivo through amino acids 160–250 of PLSCR1. Overexpression of PLSCR1 efficiently represses the Tat-dependent transactivation of the HIV-1 long terminal repeat (LTR) and reduces the nuclear translocation of Tat. In addition, shRNA-mediated suppression of endogenous PLSCR1 expression enhances the levels of gag mRNA in an HIV-1-infected T-cell line. These findings indicate that PLSCR1 negatively regulates the Tat-dependent transactivation of the HIV-1 LTR during HIV-1 infection.

  11. HIV-1 Capsid: The Multifaceted Key Player in HIV-1 infection

    PubMed Central

    Campbell, Edward M.; Hope, Thomas J.

    2016-01-01

    In a mature, infectious HIV-1 virion, the viral genome is housed within a conical capsid core comprised of the viral capsid (CA) protein. The CA protein, and the structure into which it assembles, facilitate virtually every step of infection through a series of interactions with multiple host cell factors. This review describes our understanding of the interactions between the viral capsid core and several cellular factors that enable efficient HIV-1 genome replication, timely core disassembly, nuclear import and the integration of the viral genome into the genome of the target cell. We then discuss how elucidating these interactions can reveal new targets for therapeutic interactions against HIV-1. PMID:26179359

  12. HIV-1 transcription and latency: an update

    PubMed Central

    2013-01-01

    Combination antiretroviral therapy, despite being potent and life-prolonging, is not curative and does not eradicate HIV-1 infection since interruption of treatment inevitably results in a rapid rebound of viremia. Reactivation of latently infected cells harboring transcriptionally silent but replication-competent proviruses is a potential source of persistent residual viremia in cART-treated patients. Although multiple reservoirs may exist, the persistence of resting CD4+ T cells carrying a latent infection represents a major barrier to eradication. In this review, we will discuss the latest reports on the molecular mechanisms that may regulate HIV-1 latency at the transcriptional level, including transcriptional interference, the role of cellular factors, chromatin organization and epigenetic modifications, the viral Tat trans-activator and its cellular cofactors. Since latency mechanisms may also operate at the post-transcriptional level, we will consider inhibition of nuclear RNA export and inhibition of translation by microRNAs as potential barriers to HIV-1 gene expression. Finally, we will review the therapeutic approaches and clinical studies aimed at achieving either a sterilizing cure or a functional cure of HIV-1 infection, with a special emphasis on the most recent pharmacological strategies to reactivate the latent viruses and decrease the pool of viral reservoirs. PMID:23803414

  13. Reactivation of Latent HIV-1 Expression by Engineered TALE Transcription Factors.

    PubMed

    Perdigão, Pedro; Gaj, Thomas; Santa-Marta, Mariana; Barbas, Carlos F; Goncalves, Joao

    2016-01-01

    The presence of replication-competent HIV-1 -which resides mainly in resting CD4+ T cells--is a major hurdle to its eradication. While pharmacological approaches have been useful for inducing the expression of this latent population of virus, they have been unable to purge HIV-1 from all its reservoirs. Additionally, many of these strategies have been associated with adverse effects, underscoring the need for alternative approaches capable of reactivating viral expression. Here we show that engineered transcriptional modulators based on customizable transcription activator-like effector (TALE) proteins can induce gene expression from the HIV-1 long terminal repeat promoter, and that combinations of TALE transcription factors can synergistically reactivate latent viral expression in cell line models of HIV-1 latency. We further show that complementing TALE transcription factors with Vorinostat, a histone deacetylase inhibitor, enhances HIV-1 expression in latency models. Collectively, these findings demonstrate that TALE transcription factors are a potentially effective alternative to current pharmacological routes for reactivating latent virus and that combining synthetic transcriptional activators with histone deacetylase inhibitors could lead to the development of improved therapies for latent HIV-1 infection.

  14. Gene expression profiling reveals Nef induced deregulation of lipid metabolism in HIV-1 infected T cells.

    PubMed

    Shrivastava, Surya; Trivedi, Jay; Mitra, Debashis

    2016-03-25

    Human Immunodeficiency Virus-1 (HIV-1) encodes a 27 kDa Negative Factor or Nef protein, which is increasingly proving to be a misnomer. Nef seems to be crucial for AIDS progression as individuals infected with nef-deleted strain of HIV were reported to become Long Term Non Progressors (LTNP). These findings necessitate tracing of Nef's footprint on landscape of cellular transcriptome favoring HIV-1 pathogenesis. We have tried to explore effect of Nef on cellular gene expression profile in conjunction with rest of HIV-1 proteins. Our results show that 237 genes are differentially regulated due to the presence of Nef during infection, which belong to several broad categories like "signaling", "apoptosis", "transcription" and "lipid metabolism" in gene ontology analysis. Furthermore, our results show that Nef causes disruption of lipid content in HIV-1 infected T cells. Molecular inhibitors of lipid metabolism like Atorvastatin and Ranolazine were found to have profound effect on wild type virus as compared to nef-deleted HIV-1. Thus our results suggest that interference in lipid metabolism is a potential mechanism through which Nef contributes in enhancing HIV-1 pathogenesis. PMID:26915805

  15. Cleavage of eIF4G by HIV-1 protease: effects on translation.

    PubMed

    Perales, Celia; Carrasco, Luis; Ventoso, Iván

    2003-01-01

    We have recently reported that HIV-1 protease (PR) cleaves the initiation factor of translation eIF4GI [Ventoso et al., Proc. Natl. Acad. Sci. USA 98 (2001) 12966-12971]. Here, we analyze the proteolytic activity of HIV-1 PR on eIF4GI and eIF4GII and its implications for the translation of mRNAs. HIV-1 PR efficiently cleaves eIF4GI, but not eIF4GII, in cell-free systems as well as in transfected mammalian cells. This specific proteolytic activity of the retroviral protease on eIF4GI was more selective than that observed with poliovirus 2A(pro). Despite the presence of an intact endogenous eIF4GII, cleavage of eIF4GI by HIV-1 PR was sufficient to impair drastically the translation of capped and uncapped mRNAs. In contrast, poliovirus IRES-driven translation was unaffected or even enhanced by HIV-1 PR after cleavage of eIF4GI. Further support for these in vitro results has been provided by the expression of HIV-1 PR in COS cells from a Gag-PR precursor. Our present findings suggest that eIF4GI intactness is necessary to maintain cap-dependent translation, not only in cell-free systems but also in mammalian cells.

  16. LINE-1 retrotransposable element DNA accumulates in HIV-1-infected cells.

    PubMed

    Jones, R Brad; Song, Haihan; Xu, Yang; Garrison, Keith E; Buzdin, Anton A; Anwar, Naveed; Hunter, Diana V; Mujib, Shariq; Mihajlovic, Vesna; Martin, Eric; Lee, Erika; Kuciak, Monika; Raposo, Rui André Saraiva; Bozorgzad, Ardalan; Meiklejohn, Duncan A; Ndhlovu, Lishomwa C; Nixon, Douglas F; Ostrowski, Mario A

    2013-12-01

    Type 1 long-interspersed nuclear elements (L1s) are autonomous retrotransposable elements that retain the potential for activity in the human genome but are suppressed by host factors. Retrotransposition of L1s into chromosomal DNA can lead to genomic instability, whereas reverse transcription of L1 in the cytosol has the potential to activate innate immune sensors. We hypothesized that HIV-1 infection would compromise cellular control of L1 elements, resulting in the induction of retrotransposition events. Here, we show that HIV-1 infection enhances L1 retrotransposition in Jurkat cells in a Vif- and Vpr-dependent manner. In primary CD4(+) cells, HIV-1 infection results in the accumulation of L1 DNA, at least the majority of which is extrachromosomal. These data expose an unrecognized interaction between HIV-1 and endogenous retrotransposable elements, which may have implications for the innate immune response to HIV-1 infection, as well as for HIV-1-induced genomic instability and cytopathicity.

  17. Direct Visualization of HIV-1 Replication Intermediates Shows that Capsid and CPSF6 Modulate HIV-1 Intra-nuclear Invasion and Integration.

    PubMed

    Chin, Christopher R; Perreira, Jill M; Savidis, George; Portmann, Jocelyn M; Aker, Aaron M; Feeley, Eric M; Smith, Miles C; Brass, Abraham L

    2015-11-24

    Direct visualization of HIV-1 replication would improve our understanding of the viral life cycle. We adapted established technology and reagents to develop an imaging approach, ViewHIV, which allows evaluation of early HIV-1 replication intermediates, from reverse transcription to integration. These methods permit the simultaneous evaluation of both the capsid protein (CA) and viral DNA genome (vDNA) components of HIV-1 in both the cytosol and nuclei of single cells. ViewHIV is relatively rapid, uses readily available reagents in combination with standard confocal microscopy, and can be done with virtually any HIV-1 strain and permissive cell lines or primary cells. Using ViewHIV, we find that CA enters the nucleus and associates with vDNA in both transformed and primary cells. We also find that CA's interaction with the host polyadenylation factor, CPSF6, enhances nuclear entry and potentiates HIV-1's depth of nuclear invasion, potentially aiding the virus's integration into gene-dense regions.

  18. Reprogramming Neutral Lipid Metabolism in Mouse Dendritic Leucocytes Hosting Live Leishmania amazonensis Amastigotes

    PubMed Central

    Lecoeur, Hervé; Giraud, Emilie; Prévost, Marie-Christine; Milon, Geneviève; Lang, Thierry

    2013-01-01

    Background After loading with live Leishmania (L) amazonensis amastigotes, mouse myeloid dendritic leucocytes/DLs are known to undergo reprogramming of their immune functions. In the study reported here, we investigated whether the presence of live L. amazonensis amastigotes in mouse bone marrow-derived DLs is able to trigger re-programming of DL lipid, and particularly neutral lipid metabolism. Methodology/Principal Findings Affymetrix-based transcriptional profiles were determined in C57BL/6 and DBA/2 mouse bone marrow-derived DLs that had been sorted from cultures exposed or not to live L. amazonensis amastigotes. This showed that live amastigote-hosting DLs exhibited a coordinated increase in: (i) long-chain fatty acids (LCFA) and cholesterol uptake/transport, (ii) LCFA and cholesterol (re)-esterification to triacyl-sn-glycerol (TAG) and cholesteryl esters (CE), respectively. As these neutral lipids are known to make up the lipid body (LB) core, oleic acid was added to DL cultures and LB accumulation was compared in live amastigote-hosting versus amastigote-free DLs by epi-fluorescence and transmission electron microscopy. This showed that LBs were both significantly larger and more numerous in live amastigote-hosting mouse dendritic leucocytes. Moreover, many of the larger LB showed intimate contact with the membrane of the parasitophorous vacuoles hosting the live L. amazonensis amastigotes. Conclusions/Significance As leucocyte LBs are known to be more than simple neutral lipid repositories, we set about addressing two related questions. Could LBs provide lipids to live amastigotes hosted within the DL parasitophorous vacuole and also deliver? Could LBs impact either directly or indirectly on the persistence of L. amazonensis amastigotes in rodent skin? PMID:23785538

  19. Evaluation of Health Disparity in Bacterial Vaginosis and the Implications for HIV-1 Acquisition in African American Women.

    PubMed

    Alcendor, Donald J

    2016-08-01

    There is a health disparity for both bacterial vaginosis (BV) and human immunodeficiency virus type 1 (HIV-1) infection in African American women that may be linked. The evidence that BV predisposes women to higher risk for HIV infection is well documented. The underlying mechanisms to support the epidemiological connections will require further investigations. This review explores the risk factors for BV disease with implications for HIV-1 acquisition in the context of race as a potential driver of the 20-fold increase in HIV-1 acquisition for African American women compared to white women. Specifically, it explores (i) disparities for BV in African American women, (ii) racial disparity for HIV-1 acquisition in African American women, (iii) common factors associated with BV and HIV acquisition in African American women, and (iv) potential mechanisms of the enhancement of HIV-1 transmission by BV.

  20. Glutamate metabolism in HIV-1 infected macrophages: Role of HIV-1 Vpr.

    PubMed

    Datta, Prasun K; Deshmane, Satish; Khalili, Kamel; Merali, Salim; Gordon, John C; Fecchio, Chiara; Barrero, Carlos A

    2016-09-01

    HIV-1 infected macrophages play a significant role in the neuropathogenesis of AIDS. HIV-1 viral protein R (Vpr) not only facilitates HIV-1 infection but also contribute to long-lived persistence in macrophages. Our previous studies using SILAC-based proteomic analysis showed that the expression of critical metabolic enzymes in the glycolytic pathway and tricarboxylic acid (TCA) cycle were altered in response to Vpr expression in macrophages. We hypothesized that Vpr-induced modulation of glycolysis and TCA cycle regulates glutamate metabolism and release in HIV-1 infected macrophages. We assessed the amount of specific metabolites induced by Vpr and HIV-1 in macrophages at the intracellular and extracellular level in a time-dependent manner utilizing multiple reaction monitoring (MRM) targeted metabolomics. In addition, stable isotope-labeled glucose and an MRM targeted metabolomics assay were used to evaluate the de novo synthesis and release of glutamate in Vpr overexpressing macrophages and HIV-1 infected macrophages, throughout the metabolic flux of glycolytic pathway and TCA cycle activation. The metabolic flux studies demonstrated an increase in glucose uptake, glutamate release and accumulation of α-ketoglutarate (α-KG) and glutamine in the extracellular milieu in Vpr expressing and HIV-1 infected macrophages. Interestingly, glutamate pools and other intracellular intermediates (glucose-6-phosphate (G6P), fructose-6-phosphate (F6P), citrate, malate, α-KG, and glutamine) showed a decreased trend except for fumarate, in contrast to the glutamine accumulation observed in the extracellular space in Vpr overexpressing macrophages. Our studies demonstrate that dysregulation of mitochondrial glutamate metabolism induced by Vpr in HIV-1 infected macrophages commonly seen, may contribute to neurodegeneration via excitotoxic mechanisms in the context of NeuroAIDS. PMID:27245560

  1. Constitutively Active MAVS Inhibits HIV-1 Replication via Type I Interferon Secretion and Induction of HIV-1 Restriction Factors

    PubMed Central

    Gupta, Sachin; Termini, James M.; Issac, Biju; Guirado, Elizabeth; Stone, Geoffrey W.

    2016-01-01

    Type I interferon is known to inhibit HIV-1 replication through the induction of interferon stimulated genes (ISG), including a number of HIV-1 restriction factors. To better understand interferon-mediated HIV-1 restriction, we constructed a constitutively active form of the RIG-I adapter protein MAVS. Constitutive MAVS was generated by fusion of full length MAVS to a truncated form of the Epstein Barr virus protein LMP1 (ΔLMP1). Supernatant from ΔLMP1-MAVS-transfected 293T cells contained high levels of type I interferons and inhibited HIV replication in both TZM-bl and primary human CD4+ T cells. Supernatant from ΔLMP1-MAVS-transfected 293T cells also inhibited replication of VSV-G pseudotyped single cycle SIV in TZM-bl cells, suggesting restriction was post-entry and common to both HIV and SIV. Gene array analysis of ΔLMP1-MAVS-transfected 293T cells and trans-activated CD4+ T cells showed significant upregulation of ISG, including previously characterized HIV restriction factors Viperin, Tetherin, MxB, and ISG56. Interferon blockade studies implicated interferon-beta in this response. In addition to direct viral inhibition, ΔLMP1-MAVS markedly enhanced secretion of IFN-β and IL-12p70 by dendritic cells and the activation and maturation of dendritic cells. Based on this immunostimulatory activity, an adenoviral vector (Ad5) expressing ΔLMP1-MAVS was tested as a molecular adjuvant in an HIV vaccine mouse model. Ad5-Gag antigen combined with Ad5-ΔLMP1-MAVS enhanced control of vaccinia-gag replication in a mouse challenge model, with 4/5 animals showing undetectable virus following challenge. Overall, ΔLMP1-MAVS is a promising reagent to inhibit HIV-1 replication in infected tissues and enhance vaccine-mediated immune responses, while avoiding toxicity associated with systemic type I interferon administration. PMID:26849062

  2. Constitutively Active MAVS Inhibits HIV-1 Replication via Type I Interferon Secretion and Induction of HIV-1 Restriction Factors.

    PubMed

    Gupta, Sachin; Termini, James M; Issac, Biju; Guirado, Elizabeth; Stone, Geoffrey W

    2016-01-01

    Type I interferon is known to inhibit HIV-1 replication through the induction of interferon stimulated genes (ISG), including a number of HIV-1 restriction factors. To better understand interferon-mediated HIV-1 restriction, we constructed a constitutively active form of the RIG-I adapter protein MAVS. Constitutive MAVS was generated by fusion of full length MAVS to a truncated form of the Epstein Barr virus protein LMP1 (ΔLMP1). Supernatant from ΔLMP1-MAVS-transfected 293T cells contained high levels of type I interferons and inhibited HIV replication in both TZM-bl and primary human CD4+ T cells. Supernatant from ΔLMP1-MAVS-transfected 293T cells also inhibited replication of VSV-G pseudotyped single cycle SIV in TZM-bl cells, suggesting restriction was post-entry and common to both HIV and SIV. Gene array analysis of ΔLMP1-MAVS-transfected 293T cells and trans-activated CD4+ T cells showed significant upregulation of ISG, including previously characterized HIV restriction factors Viperin, Tetherin, MxB, and ISG56. Interferon blockade studies implicated interferon-beta in this response. In addition to direct viral inhibition, ΔLMP1-MAVS markedly enhanced secretion of IFN-β and IL-12p70 by dendritic cells and the activation and maturation of dendritic cells. Based on this immunostimulatory activity, an adenoviral vector (Ad5) expressing ΔLMP1-MAVS was tested as a molecular adjuvant in an HIV vaccine mouse model. Ad5-Gag antigen combined with Ad5-ΔLMP1-MAVS enhanced control of vaccinia-gag replication in a mouse challenge model, with 4/5 animals showing undetectable virus following challenge. Overall, ΔLMP1-MAVS is a promising reagent to inhibit HIV-1 replication in infected tissues and enhance vaccine-mediated immune responses, while avoiding toxicity associated with systemic type I interferon administration. PMID:26849062

  3. The Global Transmission Network of HIV-1

    PubMed Central

    Wertheim, Joel O.; Leigh Brown, Andrew J.; Hepler, N. Lance; Mehta, Sanjay R.; Richman, Douglas D.; Smith, Davey M.; Kosakovsky Pond, Sergei L.

    2014-01-01

    Human immunodeficiency virus type 1 (HIV-1) is pandemic, but its contemporary global transmission network has not been characterized. A better understanding of the properties and dynamics of this network is essential for surveillance, prevention, and eventual eradication of HIV. Here, we apply a simple and computationally efficient network-based approach to all publicly available HIV polymerase sequences in the global database, revealing a contemporary picture of the spread of HIV-1 within and between countries. This approach automatically recovered well-characterized transmission clusters and extended other clusters thought to be contained within a single country across international borders. In addition, previously undescribed transmission clusters were discovered. Together, these clusters represent all known modes of HIV transmission. The extent of international linkage revealed by our comprehensive approach demonstrates the need to consider the global diversity of HIV, even when describing local epidemics. Finally, the speed of this method allows for near-real-time surveillance of the pandemic's progression. PMID:24151309

  4. Latency: the hidden HIV-1 challenge

    PubMed Central

    Marcello, Alessandro

    2006-01-01

    Eradication of HIV-1 from an infected individual cannot be achieved by current regimens. Viral reservoirs established early during the infection remain unaffected by anti-retroviral therapy for a long time and are able to replenish systemic infection upon interruption of the treatment. Therapeutic targeting of viral latency will require a better understanding of the basic mechanisms underlying the establishment and long-term maintenance of HIV-1 in resting memory CD4 T cells, the most prominent reservoir of transcriptionally silent provirus. Since the molecular mechanisms that permit long term transcriptional control of proviral gene expression in these cells are still obscure, this review aims at summarizing the various aspects of the problem that need to be considered. In particular, this review will focus the attention on the control of transcription imposed by chromatin through various epigenetic mechanisms. Exploring the molecular details of viral latency will provide new insights for eventual future therapeutics that aim at viral eradication. PMID:16412247

  5. Tertiary Element Interaction in HIV-1 TAR.

    PubMed

    Krawczyk, Konrad; Sim, Adelene Y L; Knapp, Bernhard; Deane, Charlotte M; Minary, Peter

    2016-09-26

    HIV-1 replication requires binding to occur between Trans-activation Response Element (TAR) RNA and the TAT protein. This TAR-TAT binding depends on the conformation of TAR, and therapeutic development has attempted to exploit this dynamic behavior. Here we simulate TAR dynamics in the context of mutations inhibiting TAR binding. We find that two tertiary elements, the apical loop and the bulge, can interact directly, and this interaction may be linked to the affinity of TAR for TAT. PMID:27500460

  6. Nanochemistry-based immunotherapy for HIV-1.

    PubMed

    Lori, F; Calarota, S A; Lisziewicz, J

    2007-01-01

    Highly active antiretroviral treatment (HAART), i.e. the combination of three or more drugs against human immunodeficiency virus type 1 (HIV-1), has greatly improved the clinical outcome of HIV-1-infected individuals. However, HAART is unable to reconstitute HIV-specific immunity and eradicate the virus. Several observations in primate models and in humans support the notion that cell-mediated immunity can control viral replication and slow disease progression. Thus, besides drugs, an immunotherapy that induces long-lasting HIV-specific T-cell responses could play a role in the treatment of HIV/AIDS. To induce such immune responses, DermaVir Patch has been developed. DermaVir consists of an HIV-1 antigen-encoding plasmid DNA that is chemically formulated in a nanoparticle. DermaVir is administered under a patch after a skin preparation that supports the delivery of the nanoparticle to Langerhans cells (LC). Epidermal LC trap and transport the nanomedicine to draining lymph nodes. While in transit, LC mature into dendritic cells (DC), which can efficiently present the DNA-encoded antigens to naïve T-cells for the induction of cellular immunity. Pre-clinical studies and Phase I clinical testing of DermaVir in HIV-1-infected individuals have demonstrated the safety and tolerability of DermaVir Patch. To further modulate cellular immunity, molecular adjuvants might be added into the nanoparticle. DermaVir Patch represents a new nanomedicine platform for immunotherapy of HIV/AIDS. In this review, the antiviral activity of DermaVir-induced cellular immunity is discussed. Furthermore, the action of some cytokines currently being tested as adjuvants are highlighted and the adjuvant effect of cytokine plasmid DNA included in the DermaVir nanoparticle is reviewed.

  7. HIV-1 infection kinetics in tissue cultures.

    PubMed

    Spouge, J I; Shrager, R I; Dimitrov, D S

    1996-11-01

    Despite intensive experimental work on HIV-1, very little theoretical work has focused on HIV-1 spread in tissue culture. This article uses two systems of ordinary differential equations to model two modes of viral spread, cell-free virus and cell-to-cell contact. The two models produce remarkably similar qualitative results. Simulations using realistic parameter regimes showed that starting with a small fraction of cells infected, both cell-free viral spread and direct cell-to-cell transmission give an initial exponential phase of viral growth, followed by either a crash or a gradual decline, extinguishing the culture. Under some conditions, an oscillatory phase may precede the extinction. Some previous models of in vivo HIV-1 infection oscillate, but only in unrealistic parameter regimes. Experimental tissue infections sometimes display several sequential cycles of oscillation, however, so our models can at least mimic them qualitatively. Significantly, the models show that infective oscillations can be explained by infection dynamics; biological heterogeneity is not required. The models also display proportionality between infected cells and cell-free virus, which is reassuringly consistent with assumptions about the equivalence of several measures of viral load, except that the proportionality requires a relatively constant total cell concentration. Tissue culture parameter values can be determined from accurate, controlled experiments. Therefore, if verified, our models should make interpreting experimental data and extrapolating it to in vivo conditions sharper and more reliable.

  8. Progress in HIV-1 Vaccine Development

    PubMed Central

    Haynes, Barton F.; McElrath, M. Juliana

    2014-01-01

    Purpose of the Review In this review, examples of recent progress in HIV-1 vaccine research are discussed. Recent Findings New insights from the immune correlates analyses of the RV144 efficacy trial have accelerated vaccine development with leads to follow in non-human primate studies and improved vaccine designs. Several new vaccine vector approaches offer promise in exquisite control of acute infection and in improving the breadth of T cell responses. New targets of broadly neutralizing antibodies (BnAbs) have been elucidated, and improved understanding of how the human host controls BnAb development have emerged from BnAb knockin mice and from analyses of BnAb maturation and virus evolution in subjects followed from the time of HIV-1 transmission to BnAb induction. Summary Based on these observations, it is clear that development of a successful HIV-1 vaccine will require new vaccine approaches and iterative testing of immunogens in well-designed animal and human trials. PMID:23743722

  9. Amastigotes of Trypanosoma cruzi escape destruction by the terminal complement components

    SciTech Connect

    Iida, K.; Whitlow, M.B.; Nussenzweig, V.

    1989-03-01

    We studied the effect of complement on two life cycle stages of the protozoan parasite Trypanosoma cruzi: epimastigotes, found in the insect vector, and amastigotes, found in the mammalian host. We found that while both stages activate vigorously the alternative pathway, only epimastigotes are destroyed. The amounts of C3 and C5b-7 deposited on the amastigotes were similar to those bound to the much larger epimastigotes. Binding of C9 to amastigotes was four to six times less than binding to epimastigotes, resulting in a lower C9/C5b-7 ratio. Although a fairly large amount of C9 bound stably to amastigotes, no functional channels were formed as measured by release of incorporated /sup 86/Rb. The bound C9 had the characteristic properties of poly-C9, that is, it expressed a neo-antigen unique to poly-C9, and migrated in SDS-PAGE with an apparent Mr greater than 10(5). The poly-C9 was removed from the surface of amastigotes by treatment with trypsin, indicating that it was not inserted in the lipid bilayer. Modification of amastigote surface by pronase treatment rendered the parasites susceptible to complement attack. These results suggest that amastigotes have a surface protein that binds to the C5b-9 complex and inhibits membrane insertion, thus protecting the parasites from complement-mediated lysis.

  10. Nup153 and Nup98 bind the HIV-1 core and contribute to the early steps of HIV-1 replication

    SciTech Connect

    Di Nunzio, Francesca; Fricke, Thomas; Miccio, Annarita; Valle-Casuso, Jose Carlos; Perez, Patricio; Souque, Philippe; Rizzi, Ermanno; Severgnini, Marco; Mavilio, Fulvio; Charneau, Pierre; Diaz-Griffero, Felipe

    2013-05-25

    The early steps of HIV-1 replication involve the entry of HIV-1 into the nucleus, which is characterized by viral interactions with nuclear pore components. HIV-1 developed an evolutionary strategy to usurp the nuclear pore machinery and chromatin in order to integrate and efficiently express viral genes. In the current work, we studied the role of nucleoporins 153 and 98 (Nup153 and Nup98) in infection of human Jurkat lymphocytes by HIV-1. We showed that Nup153-depleted cells exhibited a defect in nuclear import, while depletion of Nup 98 caused a slight defect in HIV integration. To explore the biochemical viral determinants for the requirement of Nup153 and Nup98 during HIV-1 infection, we tested the ability of these nucleoporins to interact with HIV-1 cores. Our findings showed that both nucleoporins bind HIV-1 cores suggesting that this interaction is important for HIV-1 nuclear import and/or integration. Distribution analysis of integration sites in Nup153-depleted cells revealed a reduced tendency of HIV-1 to integrate in intragenic sites, which in part could account for the large infectivity defect observed in Nup153-depleted cells. Our work strongly supports a role for Nup153 in HIV-1 nuclear import and integration. - Highlights: ► We studied the role of Nup98 and Nup153 in HIV-1 infection. ► Nup98 binds the HIV-1 core and is involved in HIV-1 integration. ► Nup153 binds the HIV-1 core and is involved in HIV-1 nuclear import. ► Depletion of Nup153 decreased the integration of HIV-1 in transcriptionally active sites.

  11. Synthesis and evaluation of orally active small molecule HIV-1 Nef antagonists.

    PubMed

    Emert-Sedlak, Lori A; Loughran, H Marie; Shi, Haibin; Kulp, John L; Shu, Sherry T; Zhao, Jielu; Day, Billy W; Wrobel, Jay E; Reitz, Allen B; Smithgall, Thomas E

    2016-03-01

    The HIV-1 Nef accessory factor enhances viral replication and promotes immune system evasion of HIV-infected cells, making it an attractive target for drug discovery. Recently we described a novel class of diphenylpyrazolodiazene compounds that bind directly to Nef in vitro and inhibit Nef-dependent HIV-1 infectivity and replication in cell culture. However, these first-generation Nef antagonists have several structural liabilities, including an azo linkage that led to poor oral bioavailability. The azo group was therefore replaced with either a one- or two-carbon linker. The resulting set of non-azo analogs retained nanomolar binding affinity for Nef by surface plasmon resonance, while inhibiting HIV-1 replication with micromolar potency in cell-based assays without cytotoxicity. Computational docking studies show that these non-azo analogs occupy the same predicted binding site within the HIV-1 Nef dimer interface as the original azo compound. Computational methods also identified a hot spot for inhibitor binding within this site that is defined by conserved HIV-1 Nef residues Asp108, Leu112, and Pro122. Pharmacokinetic evaluation of the non-azo B9 analogs in mice showed that replacement of the azo linkage dramatically enhanced oral bioavailability without substantially affecting plasma half-life or clearance. The improved oral bioavailability of non-azo diphenylpyrazolo Nef antagonists provides a starting point for further drug lead optimization in support of future efficacy testing in animal models of HIV/AIDS.

  12. Quantification of the epitope diversity of HIV-1-specific binding antibodies by peptide microarrays for global HIV-1 vaccine development

    DOE PAGESBeta

    Stephenson, Kathryn E.; Neubauer, George H.; Reimer, Ulf; Pawlowski, Nikolaus; Knaute, Tobias; Zerweck, Johannes; Korber, Bette T.; Barouch, Dan H.

    2014-11-14

    An effective vaccine against human immunodeficiency virus type 1 (HIV-1) will have to provide protection against a vast array of different HIV-1 strains. Current methods to measure HIV-1-specific binding antibodies following immunization typically focus on determining the magnitude of antibody responses, but the epitope diversity of antibody responses has remained largely unexplored. Here we describe the development of a global HIV-1 peptide microarray that contains 6564 peptides from across the HIV-1 proteome and covers the majority of HIV-1 sequences in the Los Alamos National Laboratory global HIV-1 sequence database. Using this microarray, we quantified the magnitude, breadth, and depth ofmore » IgG binding to linear HIV-1 sequences in HIV-1-infected humans and HIV-1-vaccinated humans, rhesus monkeys and guinea pigs. The microarray measured potentially important differences in antibody epitope diversity, particularly regarding the depth of epitope variants recognized at each binding site. Our data suggest that the global HIV-1 peptide microarray may be a useful tool for both preclinical and clinical HIV-1 research.« less

  13. Quantification of the epitope diversity of HIV-1-specific binding antibodies by peptide microarrays for global HIV-1 vaccine development

    SciTech Connect

    Stephenson, Kathryn E.; Neubauer, George H.; Reimer, Ulf; Pawlowski, Nikolaus; Knaute, Tobias; Zerweck, Johannes; Korber, Bette T.; Barouch, Dan H.

    2014-11-14

    An effective vaccine against human immunodeficiency virus type 1 (HIV-1) will have to provide protection against a vast array of different HIV-1 strains. Current methods to measure HIV-1-specific binding antibodies following immunization typically focus on determining the magnitude of antibody responses, but the epitope diversity of antibody responses has remained largely unexplored. Here we describe the development of a global HIV-1 peptide microarray that contains 6564 peptides from across the HIV-1 proteome and covers the majority of HIV-1 sequences in the Los Alamos National Laboratory global HIV-1 sequence database. Using this microarray, we quantified the magnitude, breadth, and depth of IgG binding to linear HIV-1 sequences in HIV-1-infected humans and HIV-1-vaccinated humans, rhesus monkeys and guinea pigs. The microarray measured potentially important differences in antibody epitope diversity, particularly regarding the depth of epitope variants recognized at each binding site. Our data suggest that the global HIV-1 peptide microarray may be a useful tool for both preclinical and clinical HIV-1 research.

  14. HIV-1 prevalence in selected Tijuana sub-populations.

    PubMed Central

    Güereña-Burgueño, F; Benenson, A S; Sepúlveda-Amor, J

    1991-01-01

    To assess the prevalence of HIV-1 (human immunodeficiency virus) infection among high-risk populations in Tijuana, Mexico, HIV-1 antibody status was determined and information on risk behavior was obtained from 1,069 individuals in three high-risk groups. The prevalence of HIV-1 among 415 prostitutes was 0.5 percent; 410 prisoners, 1.2 percent; 233 homosexual/bisexual men, 11.6 percent; and 106 intravenous drug abusers, 1.9 percent. The potential for spread of HIV-1 exists in Tijuana despite the current relatively low seroprevalence of HIV-1. PMID:2014864

  15. HIV-1 phylogenetic analysis shows HIV-1 transits through the meninges to brain and peripheral tissues.

    PubMed

    Lamers, Susanna L; Gray, Rebecca R; Salemi, Marco; Huysentruyt, Leanne C; McGrath, Michael S

    2011-01-01

    Brain infection by the human immunodeficiency virus type 1 (HIV-1) has been investigated in many reports with a variety of conclusions concerning the time of entry and degree of viral compartmentalization. To address these diverse findings, we sequenced HIV-1 gp120 clones from a wide range of brain, peripheral and meningeal tissues from five patients who died from several HIV-1 associated disease pathologies. High-resolution phylogenetic analysis confirmed previous studies that showed a significant degree of compartmentalization in brain and peripheral tissue subpopulations. Some intermixing between the HIV-1 subpopulations was evident, especially in patients that died from pathologies other than HIV-associated dementia. Interestingly, the major tissue harboring virus from both the brain and peripheral tissues was the meninges. These results show that (1) HIV-1 is clearly capable of migrating out of the brain, (2) the meninges are the most likely primary transport tissues, and (3) infected brain macrophages comprise an important HIV reservoir during highly active antiretroviral therapy.

  16. Identification and characterization of HIV-1 latent viral reservoirs in peripheral blood.

    PubMed

    Chargin, Amanda; Yin, Fangfang; Song, Min; Subramaniam, Srividyabhuvaneswari; Knutson, Grace; Patterson, Bruce K

    2015-01-01

    Plasma viral load and CD4 counts are effective for clinical monitoring, but they do not give a full representation of HIV-1 quasispecies in cellular reservoirs, the major repository of replication-competent HIV-1 in infected individuals. We sought to develop a diagnostic system that might stimulate the replication-competent HIV-1 reservoirs for enhanced clinical monitoring, including selection of antiretroviral regimens. Whole-blood samples from 45 HIV-infected individuals were collected into 1 ViraStim HIV-1 activation tube and 1 EDTA tube. Samples were tested for viral load and cell type-specific HIV-1 replication. Further, 7 matched activated/nonactivated samples were sequenced using the Trugene HIV-1 genotyping kit. The percentage of patients with replication-competent virus in peripheral blood mononuclear cells (PBMCs) varied, depending on the baseline plasma viral load in the EDTA tubes. Six out of 24 patients with a starting plasma viral load of <20 copies/ml (cp/ml), 6 out of 8 patients with starting viral loads of >20 and <1,000 cp/ml, and 8 out of 13 patients with starting viral loads of >1,000 all showed increases in viral replication of >5-fold. These increases came from cellular reservoirs in blood as determined by simultaneous ultrasensitive subpopulation staining/hybridization in situ (SUSHI). When resistance genotypes in plasma from activation tubes were compared to those from EDTA tubes for 7 patients, all patients showed additional mutations in the activation tube, while 3 patients demonstrated additional genotypic resistance determinants. We show that HIV-1 viral replication can be stimulated directly from infected whole blood. The sequencing results showed that 3 of 7 cases demonstrated additional drug resistance following stimulation. PMID:25339403

  17. Short Communication: Neutralizing Antibodies in HIV-1-Infected Brazilian Individuals

    PubMed Central

    Morgado, Mariza Gonçalvez; Côrtes, Fernanda Heloise; Guimarães, Monick Lindermeyer; Mendonça-Lima, Leila; Pilotto, Jose Henrique; Grinsztejn, Beatriz; Veloso, Valdiléa Gonçalves; Bongertz, Vera

    2013-01-01

    Abstract Tests for the detection of the humoral immune response to HIV-1 have to be standardized and established, demanding regional efforts. For this purpose the neutralizing antibody (NAb) assay for HIV-1 in TZM-bl cells was introduced in Brazil. Twenty plasma samples from HIV-1-infected individuals were assayed: 10 progressors and 10 long-term nonprogressors. These were tested against eight env-pseudotyped viruses (psVs) in the TZM-bl NAb assay and against HIV-1 strain HTLV/IIIB (HIV-1 IIIB) in primary lymphocytes. Forty-four percent of the samples showed neutralizing titers for psVs and 55% for HIV-1 IIIB. Plasma from progressors showed a broader neutralization and a higher potency. The introduction of these reference reagents encourages the participation of Brazil in future comparative assessments of anti-HIV-1 antibodies. PMID:23145941

  18. Significant impact of non-B HIV-1 variants genetic diversity in Gabon on plasma HIV-1 RNA quantitation.

    PubMed

    Mouinga-Ondémé, Augustin; Mabika-Mabika, Arsène; Alalade, Patrick; Mongo, Arnaud Delis; Sica, Jeanne; Liégeois, Florian; Rouet, François

    2014-01-01

    Evaluations of HIV-1 RNA viral load assays are lacking in Central Africa. The main objective of our study was to assess the reliability of HIV-1 RNA results obtained with three different assays for samples collected in Gabon. A total of 137 plasma specimens were assessed for HIV-1 RNA using the Abbott RealTime HIV-1® and Nuclisens HIV-1 EasyQ® version 2.0 assays. It included HIV-1 non-B samples (n = 113) representing six subtypes, 10 CRFs and 18 URFs from patients infected with HIV-1 and treated with antiretrovirals that were found HIV-1 RNA positive (≥300 copies/ml) with the Generic HIV viral load® assay; and samples (n = 24) from untreated individuals infected with HIV-1 but showing undetectable (<300 copies/ml) results with the Biocentric kit. For samples found positive with the Generic HIV viral load® test, correlation coefficients obtained between the three techniques were relatively low (R = 0.65 between Generic HIV viral load® and Abbott RealTime HIV-1®, 0.50 between Generic HIV viral load® and Nuclisens HIV-1 EasyQ®, and 0.66 between Abbott RealTime HIV-1® and Nuclisens HIV-1 EasyQ®). Discrepancies by at least one log10 were obtained for 19.6%, 33.7%, and 20% of samples, respectively, irrespective of genotype. Most of samples (22/24) from untreated study patients, found negative with the Biocentric kit, were also found negative with the two other techniques. In Central Africa, HIV-1 genetic diversity remains challenging for viral load testing. Further studies are required in the same area to confirm the presence of HIV-1 strains that are not amplified with at least two different viral load assays.

  19. ETS family proteins activate transcription from HIV-1 long terminal repeat.

    PubMed

    Seth, A; Hodge, D R; Thompson, D M; Robinson, L; Panayiotakis, A; Watson, D K; Papas, T S

    1993-10-01

    ets is a multigene family and its members share a common ETS DNA-binding domain. ETS proteins activate transcription via binding to a purine-rich GGAA core sequence located in promoters/enhancers of various genes, including several that are transcriptionally active in T cells. The ETS1, ETS2, and ERBG/Hu-FLI-1 gene expression pattern also suggests a role for these genes in cells of hematopoietic lineage. The HIV-1 LTR core enhancer contains two 10-base pair direct repeat sequences (left and right) that are required for regulation of HIV-1 mRNA expression by host transcription factors, including NF kappa B. Two ETS-binding sites are present in the core enhancer of all the HIV-1 isolates reported so far. In our studies, we utilized HIV-1 HXB2 and HIV-1 Z2Z6 core enhancers because the Z2Z6 strain has a single point mutation flanking the right ETS-binding site. We demonstrate that the ETS1, ETS2, and ERGB/Hu-FLI-1 proteins can trans-activate transcription from both the HXB2 and Z2Z6 core enhancer when linked to a reporter (cat) gene. In addition, we show that the DNA binding and trans-activation with the Z2Z6 core enhancer is at least 40-fold higher than that observed with the HXB2 core enhancer. Further, we provide evidence that the marked increase in binding and trans-activation with Z2Z6 core enhancer sequences is due to the substitution of a flanking T residue in HXB2 TGGAA) by a C residue in Z2Z6 (CGGAA) isolate, thus generating an optimal ETS-binding core (CGGAA) sequence. PMID:8280476

  20. HIV-1 VACCINES. HIV-1 neutralizing antibodies induced by native-like envelope trimers.

    PubMed

    Sanders, Rogier W; van Gils, Marit J; Derking, Ronald; Sok, Devin; Ketas, Thomas J; Burger, Judith A; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C; Julien, Jean-Philippe; Rakasz, Eva G; Seaman, Michael S; Guttman, Miklos; Lee, Kelly K; Klasse, Per Johan; LaBranche, Celia; Schief, William R; Wilson, Ian A; Overbaugh, Julie; Burton, Dennis R; Ward, Andrew B; Montefiori, David C; Dean, Hansi; Moore, John P

    2015-07-10

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505 SOSIP.664, induced NAbs potently against the sequence-matched tier 2 virus in rabbits and similar but weaker responses in macaques. The trimer also consistently induced cross-reactive NAbs against more sensitive (tier 1) viruses. Tier 2 NAbs recognized conformational epitopes that differed between animals and in some cases overlapped with those recognized by broadly neutralizing antibodies (bNAbs), whereas tier 1 responses targeted linear V3 epitopes. A second trimer, B41 SOSIP.664, also induced a strong autologous tier 2 NAb response in rabbits. Thus, native-like trimers represent a promising starting point for the development of HIV-1 vaccines aimed at inducing bNAbs.

  1. Human cytosolic extracts stabilize the HIV-1 core.

    PubMed

    Fricke, Thomas; Brandariz-Nuñez, Alberto; Wang, Xiaozhao; Smith, Amos B; Diaz-Griffero, Felipe

    2013-10-01

    The stability of the HIV-1 core in the cytoplasm is crucial for productive HIV-1 infection. Mutations that stabilize or destabilize the core showed defects on HIV-1 reverse transcription and infection. We developed a novel and simple assay to measure the stability of in vitro-assembled HIV-1 CA-NC complexes. The assay allowed us to demonstrate that cytosolic extracts strongly stabilize the HIV-1 core. Interestingly, stabilization of in vitro-assembled HIV-1 CA-NC complexes is not due solely to macromolecular crowding, suggesting the presence of specific cellular factors that stabilize the HIV-1 core. By using our novel assay, we measured the abilities of different drugs, such as PF74, CAP-1, IXN-053, cyclosporine, Bi2 (also known as BI-2), and the peptide CAI, to modulate the stability of in vitro-assembled HIV-1 CA-NC complexes. Interestingly, we found that PF74 and Bi2 strongly stabilized HIV-1 CA-NC complexes. On the other hand, the peptide CAI destabilized HIV-1 CA-NC complexes. We also found that purified cyclophilin A destabilizes in vitro-assembled HIV-1 CA-NC complexes in the presence of cellular extracts in a cyclosporine-sensitive manner. In agreement with previous observations using the fate-of-the-capsid assay, we also demonstrated the ability of recombinant CPSF6 to stabilize HIV-1 CA-NC complexes. Overall, our findings suggested that cellular extracts specifically stabilize the HIV-1 core. We believe that our assay can be a powerful tool to assess HIV-1 core stability in vitro.

  2. SAMHD1 Limits HIV-1 Antigen Presentation by Monocyte-Derived Dendritic Cells

    PubMed Central

    Bruel, Timothée; Cardinaud, Sylvain; Porrot, Françoise; Prado, Julia G.; Moris, Arnaud

    2015-01-01

    ABSTRACT Monocyte-derived dendritic cells (MDDC) stimulate CD8+ cytotoxic T lymphocytes (CTL) by presenting endogenous and exogenous viral peptides via major histocompatibility complex class I (MHC-I) molecules. MDDC are poorly susceptible to HIV-1, in part due to the presence of SAMHD1, a cellular enzyme that depletes intracellular deoxynucleoside triphosphates (dNTPs) and degrades viral RNA. Vpx, an HIV-2/SIVsm protein absent from HIV-1, antagonizes SAMHD1 by inducing its degradation. The impact of SAMHD1 on the adaptive cellular immune response remains poorly characterized. Here, we asked whether SAMHD1 modulates MHC-I-restricted HIV-1 antigen presentation. Untreated MDDC or MDDC pretreated with Vpx were exposed to HIV-1, and antigen presentation was examined by monitoring the activation of an HIV-1 Gag-specific CTL clone. SAMHD1 depletion strongly enhanced productive infection of MDDC as well as endogenous HIV-1 antigen presentation. Time-lapse microscopy analysis demonstrated that in the absence of SAMHD1, the CTL rapidly killed infected MDDC. We also report that various transmitted/founder (T/F) HIV-1 strains poorly infected MDDC and, as a consequence, did not stimulate CTL. Vesicular stomatitis virus glycoprotein (VSV-G) pseudotyping of T/F alleviated a block in viral entry and induced antigen presentation only in the absence of SAMHD1. Furthermore, by using another CTL clone that mostly recognizes incoming HIV-1 antigens, we demonstrate that SAMHD1 does not influence exogenous viral antigen presentation. Altogether, our results demonstrate that the antiviral activity of SAMHD1 impacts antigen presentation by DC, highlighting the link that exists between restriction factors and adaptive immune responses. IMPORTANCE Upon viral infection, DC may present antigens derived from incoming viral material in the absence of productive infection of DC or from newly synthesized viral proteins. In the case of HIV, productive infection of DC is blocked at an early

  3. Association of complement receptor 2 polymorphisms with innate resistance to HIV-1 infection.

    PubMed

    Herrero, R; Real, L M; Rivero-Juárez, A; Pineda, J A; Camacho, Á; Macías, J; Laplana, M; Konieczny, P; Márquez, F J; Souto, J C; Soria, J M; Saulle, I; Lo Caputo, S; Biasin, M; Rivero, A; Fibla, J; Caruz, A

    2015-03-01

    HIV-1 induces activation of complement through the classical and lectin pathways. However, the virus incorporates several membrane-bound or soluble regulators of complement activation (RCA) that inactivate complement. HIV-1 can also use the complement receptors (CRs) for complement-mediated antibody-dependent enhancement of infection (Ć-ADE). We hypothesize that hypofunctional polymorphisms in RCA or CRs may protect from HIV-1 infection. For this purpose, 139 SNPs located in 19 RCA and CRs genes were genotyped in a population of 201 Spanish HIV-1-exposed seronegative individuals (HESN) and 250 HIV-1-infected patients. Two SNPs were associated with infection susceptibility, rs1567190 in CR2 (odds ratio (OR) = 2.27, P = 1 × 10(-4)) and rs2842704 in C4BPA (OR = 2.11, P = 2 × 10(-4)). To replicate this finding, we analyzed a cohort of Italian, sexually HESN individuals. Although not significant (P = 0.25, OR = 1.57), similar genotypic proportions were obtained for the CR2 marker rs1567190. The results of the two association analyses were combined through a random effect meta-analysis, with a significant P-value of 2.6 x 10(-5) (OR = 2.07). Furthermore, we found that the protective CR2 genotype is correlated with lower levels CR2 mRNA as well as differences in the ratio of the long and short CR2 isoforms.

  4. Where in the Cell Are You? Probing HIV-1 Host Interactions through Advanced Imaging Techniques

    PubMed Central

    Dirk, Brennan S.; Van Nynatten, Logan R.; Dikeakos, Jimmy D.

    2016-01-01

    Viruses must continuously evolve to hijack the host cell machinery in order to successfully replicate and orchestrate key interactions that support their persistence. The type-1 human immunodeficiency virus (HIV-1) is a prime example of viral persistence within the host, having plagued the human population for decades. In recent years, advances in cellular imaging and molecular biology have aided the elucidation of key steps mediating the HIV-1 lifecycle and viral pathogenesis. Super-resolution imaging techniques such as stimulated emission depletion (STED) and photoactivation and localization microscopy (PALM) have been instrumental in studying viral assembly and release through both cell–cell transmission and cell–free viral transmission. Moreover, powerful methods such as Forster resonance energy transfer (FRET) and bimolecular fluorescence complementation (BiFC) have shed light on the protein-protein interactions HIV-1 engages within the host to hijack the cellular machinery. Specific advancements in live cell imaging in combination with the use of multicolor viral particles have become indispensable to unravelling the dynamic nature of these virus-host interactions. In the current review, we outline novel imaging methods that have been used to study the HIV-1 lifecycle and highlight advancements in the cell culture models developed to enhance our understanding of the HIV-1 lifecycle. PMID:27775563

  5. Inhibition of HIV-1 infection by synthetic peptides derived CCR5 fragments

    SciTech Connect

    Imai, Masaki; Baranyi, Lajos; Okada, Noriko; Okada, Hidechika; E-mail: hiokada@med.nagoya-cu.ac.jp

    2007-02-23

    HIV-1 infection requires interaction of viral envelope protein gp160 with CD4 and a chemokine receptor, CCR5 or CXCR4 as entry coreceptor. We designed HIV-inhibitory peptides targeted to CCR5 using a novel computer program (ANTIS), which searched all possible sense-antisense amino acid pairs between proteins. Seven AHBs were found in CCR5 receptor. All AHB peptides were synthesized and tested for their ability to prevent HIV-1 infection to human T cells. A peptide fragment (LC5) which is a part of the CCR5 receptor corresponding to the loop between the fifth and sixth transmembrane regions (amino acids 222-240) proved to inhibit HIV-1{sub IIIB} infection of MT-4 cells. Interaction of these antisense peptides could be involved in sustaining HIV-1 infectivity. LC5 effectively indicated dose-dependent manner, and the suppression was enhanced additively by T20 peptide, which inhibits infection in vitro by disrupting the gp41 conformational changes necessary for membrane fusion. Thus, these results indicate that CCR5-derived AHB peptides could provide a useful tool to define the mechanism(s) of HIV infection, and may provide insight which will contribute to the development of an anti-HIV-1 reagent.

  6. Active replication of HIV-1 at the lymphoepithelial surface of the tonsil.

    PubMed Central

    Frankel, S. S.; Tenner-Racz, K.; Racz, P.; Wenig, B. M.; Hansen, C. H.; Heffner, D.; Nelson, A. M.; Pope, M.; Steinman, R. M.

    1997-01-01

    Cells that are infected with HIV-1 were visualized at the mucosal surface of the nasopharyngeal and palatine tonsils in 14 specimens from patients with CD4+ T-cell counts of 200 to 900/microliter and 2- to 10-year histories of HIV-1 infection. Most of the cells with intracellular HIV-1 protein were small but multinucleated. The majority of these syncytia could be double labeled for HIV-1 RNA and a dendritic cell marker S100. In the palatine tonsil, the infected cells were not found in the stratified squamous epithelium that is adjacent to the pharynx. Instead, the S100+ infected syncytia were localized to the surface of tonsil invaginations or crypts. This mucosa, termed lymphoepithelium, contains antigen-transporting M cells that lie above regions where S100+ dendritic cells are juxtaposed with CD4+ lymphocytes. Likewise, infected cells were found in lymphoepithelium and not respiratory epithelium of nasopharyngeal tonsils or adenoids. We propose that lymphoepithelia, the histological term that describes the specialized regions where antigens access mucosa-associated lymphoid tissue, are sites where HIV-1 replication can be enhanced in syncytia derived from dendritic cells. Images Figure 1 Figure 2 Figure 3 PMID:9212735

  7. SAMHD1 restricts HIV-1 reverse transcription in quiescent CD4+ T-cells

    PubMed Central

    2012-01-01

    Background Quiescent CD4+ T lymphocytes are highly refractory to HIV-1 infection due to a block at reverse transcription. Results Examination of SAMHD1 expression in peripheral blood lymphocytes shows that SAMHD1 is expressed in both CD4+ and CD8+ T cells at levels comparable to those found in myeloid cells. Treatment of CD4+ T cells with Virus-Like Particles (VLP) containing Vpx results in the loss of SAMHD1 expression that correlates with an increased permissiveness to HIV-1 infection and accumulation of reverse transcribed viral DNA without promoting transcription from the viral LTR. Importantly, CD4+ T-cells from patients with Aicardi-Goutières Syndrome harboring mutation in the SAMHD1 gene display an increased susceptibility to HIV-1 infection that is not further enhanced by VLP-Vpx-treatment. Conclusion Here, we identified SAMHD1 as the restriction factor preventing efficient viral DNA synthesis in non-cycling resting CD4+ T-cells. These results highlight the crucial role of SAMHD1 in mediating restriction of HIV-1 infection in quiescent CD4+ T-cells and could impact our understanding of HIV-1 mediated CD4+ T-cell depletion and establishment of the viral reservoir, two of the HIV/AIDS hallmarks. PMID:23092122

  8. Discovery and crystallography of bicyclic arylaminoazines as potent inhibitors of HIV-1 reverse transcriptase.

    PubMed

    Lee, Won-Gil; Frey, Kathleen M; Gallardo-Macias, Ricardo; Spasov, Krasimir A; Chan, Albert H; Anderson, Karen S; Jorgensen, William L

    2015-11-01

    Non-nucleoside inhibitors of HIV-1 reverse transcriptase (HIV-RT) are reported that incorporate a 7-indolizinylamino or 2-naphthylamino substituent on a pyrimidine or 1,3,5-triazine core. The most potent compounds show below 10 nanomolar activity towards wild-type HIV-1 and variants bearing Tyr181Cys and Lys103Asn/Tyr181Cys resistance mutations. The compounds also feature good aqueous solubility. Crystal structures for two complexes enhance the analysis of the structure-activity data.

  9. Induction of HIV-1 long terminal repeat-mediated transcription by Neisseria gonorrhoeae.

    PubMed

    Chen, Adrienne; Boulton, Ian C; Pongoski, Jodi; Cochrane, Alan; Gray-Owen, Scott D

    2003-03-01

    Gonorrhoea enhances the transmission of HIV through increased viral shedding and the increased probability of seroconversion among previously HIV-negative individuals. However, the mechanism(s) underlying these influences remain poorly understood. We demonstrated that exposure to Neisseria gonorrhoeae induces the nuclear factor kappa B-dependent transcription from the HIV-1 long terminal repeat in derivatives of the Jurkat CD4 T cell line. These data suggest that gonococcal infection directly impacts HIV-1 transmission through the localized stimulation of viral expression. PMID:12598784

  10. Crystallization studies on HIV-1 reverse transcriptase

    NASA Astrophysics Data System (ADS)

    Lloyd, Lesley F.; Brick, Peter; Blow, David M.; Mei-Zhen, Lou

    1992-08-01

    HIV-1 reverse transcriptase has been crystallized in a variety of forms. Various ligands used for co-crystallization are described and the results presented. All of these crystals showed disorder when examined in the X-ray beam. The best diffraction currently achieved has been approximately 7A˚. The possible reasons for crystal disorder are discussed. An example of another protein, car☐ypeptidase G 2, which initially yielded non-diffracting crystals, is used to illustrate the value of applying random or incomplete factorial screens to sample wider parameter space for conditions to grow well-ordered crystals.

  11. Rigidity analysis of HIV-1 protease

    NASA Astrophysics Data System (ADS)

    Heal, J. W.; Wells, S. A.; Jimenez-Roldan, E.; Freedman, R. F.; Römer, R. A.

    2011-03-01

    We present a rigidity analysis on a large number of X-ray crystal structures of the enzyme HIV-1 protease using the 'pebble game' algorithm of the software FIRST. We find that although the rigidity profile remains similar across a comprehensive set of high resolution structures, the profile changes significantly in the presence of an inhibitor. Our study shows that the action of the inhibitors is to restrict the flexibility of the β-hairpin flaps which allow access to the active site. The results are discussed in the context of full molecular dynamics simulations as well as data from NMR experiments.

  12. An empiric risk scoring tool for identifying high-risk heterosexual HIV-1 serodiscordant couples for targeted HIV-1 prevention

    PubMed Central

    KAHLE, Erin M.; HUGHES, James P.; LINGAPPA, Jairam R.; JOHN-STEWART, Grace; CELUM, Connie; NAKKU-JOLOBA, Edith; NJUGUNA, Stella; MUGO, Nelly; BUKUSI, Elizabeth; MANONGI, Rachel; BAETEN, Jared M.

    2012-01-01

    Background and objectives Heterosexual HIV-1 serodiscordant couples are increasingly recognized as an important source of new HIV-1 infections in sub-Saharan Africa. A simple risk assessment tool could be useful for identifying couples at highest risk for HIV-1 transmission. Methods Using data from three prospective studies of HIV-1 serodiscordant couples from seven African countries and standard methods for development of clinical prediction rules, we derived and validated a risk scoring tool developed from multivariate modeling and composed of key predictors for HIV-1 risk that could be measured in standard research and clinical settings. Results The final risk score included age of the HIV-1 uninfected partner, married and/or cohabiting partnership, number of children, unprotected sex, uncircumcised male HIV-1 uninfected partner, and plasma HIV-1 RNA in the HIV-1 infected partner. The maximum risk score was 12, scores ≥5 were associated with an annual HIV-1 incidence of >3%, and couples with a score ≥6 accounted for only 28% of the population but 67% of HIV-1 transmissions. The area under the curve for predictive ability of the score was 0.74 (95% CI 0.70–0.78). Internal and external validation showed similar predictive ability of the risk score, even when plasma viral load was excluded from the risk score. Conclusions A discrete combination of clinical and behavioral characteristics defines highest-risk HIV-1 serodiscordant couples. Discriminating highest-risk couples for HIV-1 prevention programs and clinical trials using a validated risk score could improve research efficiency and maximize the impact of prevention strategies for reducing HIV-1 transmission. PMID:23187945

  13. Leishmania pifanoi amastigotes avoid macrophage production of superoxide by inducing heme degradation.

    PubMed

    Pham, Nam-Kha; Mouriz, Jennifer; Kima, Peter E

    2005-12-01

    Whereas infections of macrophages by promastigote forms of Leishmania mexicana pifanoi induce the production of superoxide, infections by amastigotes barely induce superoxide production. Several approaches were employed to gain insight into the mechanism by which amastigotes avoid eliciting superoxide production. First, in experiments with nitroblue tetrazolium, we found that 25% of parasitophorous vacuoles (PVs) that harbor promastigotes are positive for the NADPH oxidase complex, in contrast to only 2% of PVs that harbor amastigotes. Second, confocal microscope analyses of infected cells labeled with antibodies to gp91phox revealed that this enzyme subunit is found in PVs that harbor amastigotes. Third, in immunoblots of subcellular fractions enriched with PVs from amastigote-infected cells and probed with antibodies to gp91phox, only the 65-kDa premature form of gp91phox was found. In contrast, subcellular fractions from macrophages that ingested zymosan particles contained both the 91- and 65-kDa forms of gp91phox. This suggested that only the immature form of gp91phox is recruited to PVs that harbor amastigotes. Given that gp91phox maturation is dependent on the availability of heme, we found that infections by Leishmania parasites induce an increase in heme oxygenase 1 (HO-1), the rate-limiting enzyme in heme degradation. Infections by amastigotes performed in the presence of metalloporphyrins, which are inhibitors of HO-1, resulted in superoxide production by infected macrophages. Taken together, we propose that Leishmania amastigotes avoid superoxide production by inducing an increase in heme degradation, which results in blockage of the maturation of gp91phox, which prevents assembly of the NADPH oxidase enzyme complex.

  14. Bioactivity of flavonoids isolated from Lychnophora markgravii against Leishmania amazonensis amastigotes.

    PubMed

    Salvador, Marcos José; Sartori, Fabiana Terezinha; Sacilotto, Ana Claudia B C; Pral, Elizabeth M F; Alfieri, Silvia Celina; Vichnewski, Walter

    2009-01-01

    The bioactivity of the flavonoids pinostrobin (1), pinocembrin (2), tectochrysin (3), galangin 3-methyl ether (4), and tiliroside (5) isolated from Lychnophora markgravii aerial parts was investigated in vitro against amastigote stages of Leishmania amazonensis. The compounds were isolated by several chromatographic techniques and their chemical structures were established by ESI-MS and NMR spectroscopic data. The flavonoids 1 and 3 were the most active compounds; they markedly reduced the viability of Leishmania amastigotes.

  15. Dynamics of the human and viral m(6)A RNA methylomes during HIV-1 infection of T cells.

    PubMed

    Lichinchi, Gianluigi; Gao, Shang; Saletore, Yogesh; Gonzalez, Gwendolyn Michelle; Bansal, Vikas; Wang, Yinsheng; Mason, Christopher E; Rana, Tariq M

    2016-01-01

    N(6)-methyladenosine (m(6)A) is the most prevalent internal modification of eukaryotic mRNA. Very little is known of the function of m(6)A in the immune system or its role in host-pathogen interactions. Here, we investigate the topology, dynamics and bidirectional influences of the viral-host RNA methylomes during HIV-1 infection of human CD4 T cells. We show that viral infection triggers a massive increase in m(6)A in both host and viral mRNAs. In HIV-1 mRNA, we identified 14 methylation peaks in coding and noncoding regions, splicing junctions and splicing regulatory sequences. We also identified a set of 56 human gene transcripts that were uniquely methylated in HIV-1-infected T cells and were enriched for functions in viral gene expression. The functional relevance of m(6)A for viral replication was demonstrated by silencing of the m(6)A writer or the eraser enzymes, which decreased or increased HIV-1 replication, respectively. Furthermore, methylation of two conserved adenosines in the stem loop II region of HIV-1 Rev response element (RRE) RNA enhanced binding of HIV-1 Rev protein to the RRE in vivo and influenced nuclear export of RNA. Our results identify a new mechanism for the control of HIV-1 replication and its interaction with the host immune system. PMID:27572442

  16. Immunization for HIV-1 Broadly Neutralizing Antibodies in Human Ig Knockin Mice.

    PubMed

    Dosenovic, Pia; von Boehmer, Lotta; Escolano, Amelia; Jardine, Joseph; Freund, Natalia T; Gitlin, Alexander D; McGuire, Andrew T; Kulp, Daniel W; Oliveira, Thiago; Scharf, Louise; Pietzsch, John; Gray, Matthew D; Cupo, Albert; van Gils, Marit J; Yao, Kai-Hui; Liu, Cassie; Gazumyan, Anna; Seaman, Michael S; Björkman, Pamela J; Sanders, Rogier W; Moore, John P; Stamatatos, Leonidas; Schief, William R; Nussenzweig, Michel C

    2015-06-18

    A subset of individuals infected with HIV-1 develops broadly neutralizing antibodies (bNAbs) that can prevent infection, but it has not yet been possible to elicit these antibodies by immunization. To systematically explore how immunization might be tailored to produce them, we generated mice expressing the predicted germline or mature heavy chains of a potent bNAb to the CD4 binding site (CD4bs) on the HIV-1 envelope glycoprotein (Env). Immunogens specifically designed to activate B cells bearing germline antibodies are required to initiate immune responses, but they do not elicit bNAbs. In contrast, native-like Env trimers fail to activate B cells expressing germline antibodies but elicit bNAbs by selecting for a restricted group of light chains bearing specific somatic mutations that enhance neutralizing activity. The data suggest that vaccination to elicit anti-HIV-1 antibodies will require immunization with a succession of related immunogens.

  17. The Role of Select Subtype Polymorphisms on HIV-1 Protease Conformational Sampling and Dynamics*

    PubMed Central

    Huang, Xi; Britto, Manuel D.; Kear-Scott, Jamie L.; Boone, Christopher D.; Rocca, James R.; Simmerling, Carlos; Mckenna, Robert; Bieri, Michael; Gooley, Paul R.; Dunn, Ben M.; Fanucci, Gail E.

    2014-01-01

    HIV-1 protease is an essential enzyme for viral particle maturation and is a target in the fight against HIV-1 infection worldwide. Several natural polymorphisms are also associated with drug resistance. Here, we utilized both pulsed electron double resonance, also called double electron-electron resonance, and NMR 15N relaxation measurements to characterize equilibrium conformational sampling and backbone dynamics of an HIV-1 protease construct containing four specific natural polymorphisms commonly found in subtypes A, F, and CRF_01 A/E. Results show enhanced backbone dynamics, particularly in the flap region, and the persistence of a novel conformational ensemble that we hypothesize is an alternative flap orientation of a curled open state or an asymmetric configuration when interacting with inhibitors. PMID:24742668

  18. Contribution of the 80s loop of HIV-1 protease to the multidrug-resistance mechanism: crystallographic study of MDR769 HIV-1 protease variants

    SciTech Connect

    Yedidi, Ravikiran S.; Proteasa, Georghe; Martinez, Jorge L.; Vickrey, John F.; Martin, Philip D.; Wawrzak, Zdzislaw; Liu, Zhigang; Kovari, Iulia A.; Kovari, Ladislau C.

    2011-09-06

    The flexible flaps and the 80s loops (Pro79-Ile84) of HIV-1 protease are crucial in inhibitor binding. Previously, it was reported that the crystal structure of multidrug-resistant 769 (MDR769) HIV-1 protease shows a wide-open conformation of the flaps owing to conformational rigidity acquired by the accumulation of mutations. In the current study, the effect of mutations on the conformation of the 80s loop of MDR769 HIV-1 protease variants is reported. Alternate conformations of Pro81 (proline switch) with a root-mean-square deviation of 3-4.8 {angstrom} in the C{alpha} atoms of the I10V mutant and a side chain with a 'flipped-out' conformation in the A82F mutant cause distortion in the S1/S1' binding pockets that affects inhibitor binding. The A82S and A82T mutants show local changes in the electrostatics of inhibitor binding owing to the mutation from nonpolar to polar residues. In summary, the crystallographic studies of four variants of MDR769 HIV-1 protease presented in this article provide new insights towards understanding the drug-resistance mechanism as well as a basis for design of future protease inhibitors with enhanced potency.

  19. Dense display of HIV-1 envelope spikes on the lambda phage scaffold does not result in the generation of improved antibody responses to HIV-1 Env

    PubMed Central

    Mattiacio, Jonelle; Walter, Scott; Brewer, Matt; Domm, William; Friedman, Alan E.; Dewhurst, Stephen

    2011-01-01

    The generation of strong, virus-neutralizing antibody responses to the HIV-1 envelope spike (Env) is a major goal in HIV-1 vaccine research. To try to enhance the Env-specific response, we displayed oligomeric gp140 on a virus-like scaffold provided by the lambda phage capsid. To do this, an in vitro complementation system was used to “decorate” phage particles with glycosylated, mammalian cell-derived envelope oligomers. We compared the immune response to lambda phage particles displaying HIV-1 Env to that elicited by soluble oligomeric gp140 in rabbits. Env-binding antibody titers were higher in animals that received oligomeric gp140 as compared to Env decorated phage particles, as were virus neutralizing antibody responses. The Env decorated phage particles were, however, able to efficiently boost a protein-primed humoral response to levels equivalent to those elicited by high-dose adjuvanted Env oligomers. These results show that display of HIV-1 envelope spikes on the bacteriophage lambda capsid does not result in an improved, Env-specific humoral immune response. PMID:21310193

  20. High Degree of HIV-1 Group M (HIV-1M) Genetic Diversity within Circulating Recombinant Forms: Insight into the Early Events of HIV-1M Evolution

    PubMed Central

    2015-01-01

    ABSTRACT The existence of various highly divergent HIV-1 lineages and of recombination-derived sequence tracts of indeterminate origin within established circulating recombinant forms (CRFs) strongly suggests that HIV-1 group M (HIV-1M) diversity is not fully represented under the current classification system. Here we used a fully exploratory screen for recombination on a set of 480 near-full-length genomes representing the full known diversity of HIV-1M. We decomposed recombinant sequences into their constituent parts and then used maximum-likelihood phylogenetic analyses of this mostly recombination-free data set to identify rare divergent sequence lineages that fall outside the major named HIV-1M taxonomic groupings. We found that many of the sequence fragments occurring within CRFs (including CRF04_cpx, CRF06_cpx, CRF11_cpx, CRF18_cpx, CRF25_cpx, CRF27_cpx, and CRF49_cpx) are in fact likely derived from divergent unclassified parental lineages that may predate the current subtypes, even though they are presently identified as derived from currently defined HIV-1M subtypes. Our evidence suggests that some of these CRFs are descended predominantly from what were or are major previously unidentified HIV-1M lineages that were likely epidemiologically relevant during the early stages of the HIV-1M epidemic. The restriction of these divergent lineages to the Congo basin suggests that they were less infectious and/or simply not present at the time and place of the initial migratory wave that triggered the global epidemic. IMPORTANCE HIV-1 group M (HIV-1M) likely spread to the rest of the world from the Congo basin in the mid-1900s (N. R. Faria et al., Science 346:56–61, 2014, http://dx.doi.org/10.1126/science.1256739) and is today the principal cause of the AIDS pandemic. Here, we show that large sequence fragments from several HIV-1M circulating recombinant forms (CRFs) are derived from divergent parental lineages that cannot reasonably be classified within the

  1. Leishmania amazonensis amastigotes highly express a tryparedoxin peroxidase isoform that increases parasite resistance to macrophage antimicrobial defenses and fosters parasite virulence.

    PubMed

    Henard, Calvin A; Carlsen, Eric D; Hay, Christie; Kima, Peter E; Soong, Lynn

    2014-07-01

    Professional phagocytes generate a myriad of antimicrobial molecules to kill invading microorganisms, of which nitrogen oxides are integral in controlling the obligate intracellular pathogen Leishmania. Although reactive nitrogen species produced by the inducible nitric oxide synthase (iNOS) can promote the clearance of intracellular parasites, some Leishmania species/stages are relatively resistant to iNOS-mediated antimicrobial activity. The underlying mechanism for this resistance remains largely uncharacterized. Here, we show that the amastigote form of L. amazonensis is hyper-resistant to the antimicrobial actions of cytokine-activated murine and human macrophages as compared to its promastigote counterpart. Amastigotes exhibit a marked ability to directly counter the cytotoxicity of peroxynitrite (ONOO-), a leishmanicidal oxidant that is generated during infection through the combined enzymatic activities of NADPH oxidase and iNOS. The enhanced antinitrosative defense of amastigotes correlates with the increased expression of a tryparedoxin peroxidase (TXNPx) isoform that is also upregulated in response to iNOS enzymatic activity within infected macrophages. Accordingly, ectopic over-expression of the TXNPx isoform by L. amazonensis promastigotes significantly enhances parasite resistance against ONOO- cytotoxicity. Moreover, TXNPx-overexpressing parasites exhibit greater intra-macrophage survival, and increased parasite growth and lesion development in a murine model of leishmaniasis. Our investigations indicate that TXNPx isoforms contribute to Leishmania's ability to adapt to and antagonize the hostile microenvironment of cytokine-activated macrophages, and provide a mechanistic explanation for persistent infection in experimental and human leishmaniasis.

  2. Leishmania amazonensis Amastigotes Highly Express a Tryparedoxin Peroxidase Isoform That Increases Parasite Resistance to Macrophage Antimicrobial Defenses and Fosters Parasite Virulence

    PubMed Central

    Henard, Calvin A.; Carlsen, Eric D.; Hay, Christie; Kima, Peter E.; Soong, Lynn

    2014-01-01

    Professional phagocytes generate a myriad of antimicrobial molecules to kill invading microorganisms, of which nitrogen oxides are integral in controlling the obligate intracellular pathogen Leishmania. Although reactive nitrogen species produced by the inducible nitric oxide synthase (iNOS) can promote the clearance of intracellular parasites, some Leishmania species/stages are relatively resistant to iNOS-mediated antimicrobial activity. The underlying mechanism for this resistance remains largely uncharacterized. Here, we show that the amastigote form of L. amazonensis is hyper-resistant to the antimicrobial actions of cytokine-activated murine and human macrophages as compared to its promastigote counterpart. Amastigotes exhibit a marked ability to directly counter the cytotoxicity of peroxynitrite (ONOO−), a leishmanicidal oxidant that is generated during infection through the combined enzymatic activities of NADPH oxidase and iNOS. The enhanced antinitrosative defense of amastigotes correlates with the increased expression of a tryparedoxin peroxidase (TXNPx) isoform that is also upregulated in response to iNOS enzymatic activity within infected macrophages. Accordingly, ectopic over-expression of the TXNPx isoform by L. amazonensis promastigotes significantly enhances parasite resistance against ONOO− cytotoxicity. Moreover, TXNPx-overexpressing parasites exhibit greater intra-macrophage survival, and increased parasite growth and lesion development in a murine model of leishmaniasis. Our investigations indicate that TXNPx isoforms contribute to Leishmania's ability to adapt to and antagonize the hostile microenvironment of cytokine-activated macrophages, and provide a mechanistic explanation for persistent infection in experimental and human leishmaniasis. PMID:25033301

  3. HIV-1 Tat Protein Increases Microglial Outward K+ Current and Resultant Neurotoxic Activity

    PubMed Central

    Liu, Jianuo; Xu, Peng; Collins, Cory; Liu, Han; Zhang, Jingdong; Keblesh, James P.; Xiong, Huangui

    2013-01-01

    Microglia plays a crucial role in the pathogenesis of HIV-1-associated neurocognitive disorders. Increasing evidence indicates the voltage-gated potassium (Kv) channels are involved in the regulation of microglia function, prompting us to hypothesize Kv channels may also be involved in microglia-mediated neurotoxic activity in HIV-1-infected brain. To test this hypothesis, we investigated the involvement of Kv channels in the response of microglia to HIV-1 Tat protein. Treatment of rat microglia with HIV-1 Tat protein (200 ng/ml) resulted in pro-inflammatory microglial activation, as indicated by increases in TNF-α, IL-1β, reactive oxygen species, and nitric oxide, which were accompanied by enhanced outward K+ current and Kv1.3 channel expression. Suppression of microglial Kv1.3 channel activity, either with Kv1.3 channel blockers Margatoxin, 5-(4-Phenoxybutoxy)psoralen, or broad-spectrum K+ channel blocker 4-Aminopyridine, or by knockdown of Kv1.3 expression via transfection of microglia with Kv1.3 siRNA, was found to abrogate the neurotoxic activity of microglia resulting from HIV-1 Tat exposure. Furthermore, HIV-1 Tat-induced neuronal apoptosis was attenuated with the application of supernatant collected from K+ channel blocker-treated microglia. Lastly, the intracellular signaling pathways associated with Kv1.3 were investigated and enhancement of microglial Kv1.3 was found to correspond with an increase in Erk1/2 mitogen-activated protein kinase activation. These data suggest targeting microglial Kv1.3 channels may be a potential new avenue of therapy for inflammation-mediated neurological disorders. PMID:23738010

  4. Fucoidans as Potential Inhibitors of HIV-1

    PubMed Central

    Prokofjeva, Maria M.; Imbs, Tatyana I.; Shevchenko, Natalya M.; Spirin, Pavel V.; Horn, Stefan; Fehse, Boris; Zvyagintseva, Tatyana N.; Prassolov, Vladimir S.

    2013-01-01

    The antiviral activity of different structure fucoidans (α-l-fucans and galactofucans) was studied using two model viral systems based on a lentiviral vectors and a replication competent Moloney murine leukemia virus (Mo-MuLV). It was found that investigated fucoidans have no cytotoxic effects on Jurkat and SC-1cell at the concentration range of 0.001–100 µg/mL. Fucoidans with different efficiency suppressed transduction of Jurkat cell line by pseudo-HIV-1 particles carrying the envelope protein of HIV-1 and infection of SC-1 cells by Mo-MuLV. According to our data, all natural fucoidans can be considered as potential anti-HIV agents regardless of their carbohydrate backbone and degree of sulfating, since their activity is shown at low concentrations (0.001–0.05 µg/mL). High molecular weight fucoidans isolated from Saccharina cichorioides (1.3-α-l-fucan), and S. japonica (galactofucan) were the most effective inhibitors. PMID:23966033

  5. Fucoidans as potential inhibitors of HIV-1.

    PubMed

    Prokofjeva, Maria M; Imbs, Tatyana I; Shevchenko, Natalya M; Spirin, Pavel V; Horn, Stefan; Fehse, Boris; Zvyagintseva, Tatyana N; Prassolov, Vladimir S

    2013-08-19

    The antiviral activity of different structure fucoidans (α-l-fucans and galactofucans) was studied using two model viral systems based on a lentiviral vectors and a replication competent Moloney murine leukemia virus (Mo-MuLV). It was found that investigated fucoidans have no cytotoxic effects on Jurkat and SC-1cell at the concentration range of 0.001-100 µg/mL. Fucoidans with different efficiency suppressed transduction of Jurkat cell line by pseudo-HIV-1 particles carrying the envelope protein of HIV-1 and infection of SC-1 cells by Mo-MuLV. According to our data, all natural fucoidans can be considered as potential anti-HIV agents regardless of their carbohydrate backbone and degree of sulfating, since their activity is shown at low concentrations (0.001-0.05 µg/mL). High molecular weight fucoidans isolated from Saccharina cichorioides (1.3-α-l-fucan), and S. japonica (galactofucan) were the most effective inhibitors.

  6. Vaccination with a Fusion Protein That Introduces HIV-1 Gag Antigen into a Multitrimer CD40L Construct Results in Enhanced CD8+ T Cell Responses and Protection from Viral Challenge by Vaccinia-Gag

    PubMed Central

    Gupta, Sachin; Termini, James M.; Raffa, Francesca N.; Williams, Cindi-Ann; Kornbluth, Richard S.

    2014-01-01

    CD40 ligand (CD40L, CD154) is a membrane protein that is important for the activation of dendritic cells (DCs) and DC-induced CD8+ T cell responses. To be active, CD40L must cluster CD40 receptors on responding cells. To produce a soluble form of CD40L that clusters CD40 receptors necessitates the use of a multitrimer construct. With this in mind, a tripartite fusion protein was made from surfactant protein D (SPD), HIV-1 Gag as a test antigen, and CD40L, where SPD serves as a scaffold for the multitrimer protein complex. This SPD-Gag-CD40L protein activated CD40-bearing cells and bone marrow-derived DCs in vitro. Compared to a plasmid for Gag antigen alone (pGag), DNA vaccination of mice with pSPD-Gag-CD40L induced an increased number of Gag-specific CD8+ T cells with increased avidity for major histocompatibility complex class I-restricted Gag peptide and improved vaccine-induced protection from challenge by vaccinia-Gag virus. The importance of the multitrimeric nature of the complex was shown using a plasmid lacking the N terminus of SPD that produced a single trimer fusion protein. This plasmid, pTrimer-Gag-CD40L, was only weakly active on CD40-bearing cells and did not elicit strong CD8+ T cell responses or improve protection from vaccinia-Gag challenge. An adenovirus 5 (Ad5) vaccine incorporating SPD-Gag-CD40L was much stronger than Ad5 expressing Gag alone (Ad5-Gag) and induced complete protection (i.e., sterilizing immunity) from vaccinia-Gag challenge. Overall, these results show the potential of a new vaccine design in which antigen is introduced into a construct that expresses a multitrimer soluble form of CD40L, leading to strongly protective CD8+ T cell responses. PMID:24227853

  7. Purinergic Receptors: Key Mediators of HIV-1 Infection and Inflammation

    PubMed Central

    Swartz, Talia H.; Dubyak, George R.; Chen, Benjamin K.

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) causes a chronic infection that afflicts more than 30 million individuals worldwide. While the infection can be suppressed with potent antiretroviral therapies, individuals infected with HIV-1 have elevated levels of inflammation as indicated by increased T cell activation, soluble biomarkers, and associated morbidity and mortality. A single mechanism linking HIV-1 pathogenesis to this inflammation has yet to be identified. Purinergic receptors are known to mediate inflammation and have been shown to be required for HIV-1 infection at the level of HIV-1 membrane fusion. Here, we review the literature on the role of purinergic receptors in HIV-1 infection and associated inflammation and describe a role for these receptors as potential therapeutic targets. PMID:26635799

  8. Raltegravir, an HIV-1 integrase inhibitor for HIV infection.

    PubMed

    Cabrera, Cecilia

    2008-08-01

    Merck & Co has developed and launched raltegravir, an HIV-1 integrase inhibitor for the treatment of HIV-1 infection in treatment-experienced adult patients who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents. This drug is the lead from a series of integrase strand transfer inhibitors and, by April 2008, it had been launched in Canada, the US, the UK, France, Germany and Spain, and had been filed for approval in Japan.

  9. Structured treatment interruptions to control HIV-1 infection.

    PubMed

    Lori, F; Maserati, R; Foli, A; Seminari, E; Timpone, J; Lisziewicz, J

    2000-01-22

    Structured treatment interruptions progressively lowered the rate of viral rebound in some HIV-1 infected patients. This approach should be explored as an alternative to continuous antiretroviral therapies.

  10. Broad activation of latent HIV-1 in vivo.

    PubMed

    Barton, Kirston; Hiener, Bonnie; Winckelmann, Anni; Rasmussen, Thomas Aagaard; Shao, Wei; Byth, Karen; Lanfear, Robert; Solomon, Ajantha; McMahon, James; Harrington, Sean; Buzon, Maria; Lichterfeld, Mathias; Denton, Paul W; Olesen, Rikke; Østergaard, Lars; Tolstrup, Martin; Lewin, Sharon R; Søgaard, Ole Schmeltz; Palmer, Sarah

    2016-01-01

    The 'shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4(+) T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate measure of HIV-1 reservoir size. Our findings provide insights into the effects of panobinostat and vorinostat as LRAs for latent HIV-1. PMID:27605062

  11. Broad activation of latent HIV-1 in vivo

    PubMed Central

    Barton, Kirston; Hiener, Bonnie; Winckelmann, Anni; Rasmussen, Thomas Aagaard; Shao, Wei; Byth, Karen; Lanfear, Robert; Solomon, Ajantha; McMahon, James; Harrington, Sean; Buzon, Maria; Lichterfeld, Mathias; Denton, Paul W.; Olesen, Rikke; Østergaard, Lars; Tolstrup, Martin; Lewin, Sharon R.; Søgaard, Ole Schmeltz; Palmer, Sarah

    2016-01-01

    The ‘shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4+ T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate measure of HIV-1 reservoir size. Our findings provide insights into the effects of panobinostat and vorinostat as LRAs for latent HIV-1. PMID:27605062

  12. Detection of diverse HIV-1 genetic subtypes in the USA.

    PubMed

    Brodine, S K; Mascola, J R; Weiss, P J; Ito, S I; Porter, K R; Artenstein, A W; Garland, F C; McCutchan, F E; Burke, D S

    1995-11-01

    Of the nine genetic subtypes of HIV-1 that exist world wide, subtype B predominates in North America and Europe. Thus, most knowledge about HIV-1 and most vaccine development efforts are based on subtype B viruses. We document here the detection of HIV-1 subtypes A, D, and E in five US servicemen who acquired these non-subtype-B infections during overseas deployments. The dispersal of diverse HIV-1 subtypes into regions of the world with previously restricted genetic diversity may have important implications for the epidemiology of the epidemic and for the design and implementation of vaccine trials. PMID:7475661

  13. [Effective components against HIV-1 replicative enzymes isolated from plants].

    PubMed

    Peng, Zong-gen; Xu, Li-jia; Ye, Wen-cai; Xiao, Pei-gen; Chen, Hong-shan

    2010-02-01

    Plant active components characterized of many different structures and activities on multiple targets, have made them to be the important sources of inhibitors on HIV-1. For finding leading compounds with new structure against HIV-1, three key HIV-1 replicative enzymes (reverse transcriptase, protease and integrase) were used as screening models. The in vitro activities of 45 plant derived components isolated from Schisandraceae, Rutaceae and Ranunculaceae were reported. Within twelve triterpene components isolated, eight compounds were found to inhibit HIV-1 protease, in these eight active compounds, kadsuranic acid A (7) and nigranoic acid (8), inhibited both HIV-1 protease and integrase; Among fifteen lignans, meso-dihydroguaiaretic acid (15) and kadsurarin (16) were active on HIV-1 reverse transcriptase, and 4, 4-di(4-hydroxy-3-methoxyphenly)-2, 3-dimethylbutanol (13) active on HIV-1 integrase. All of the six alkaloids, seven flavones, and five others compounds were not active or only with low activities against HIV-1 replicative enzymes. Further studies of the triterpene components showing strong inhibitory activities on HIV-1 were warranted.

  14. Genome editing strategies: potential tools for eradicating HIV-1/AIDS

    PubMed Central

    Khalili, Kamel; Gordon, Jennifer; Cosentino, Laura; Hu, Wenhui

    2015-01-01

    Current therapy for controlling HIV-1 infection and preventing AIDS progression has profoundly decreased viral replication in cells susceptible to HIV-1 infection, but it does not eliminate the low level of viral replication in latently infected cells which contain integrated copies of HIV-1 proviral DNA. There is an urgent need for the development of HIV-1 genome eradication strategies that will lead to a permanent or “sterile” cure of HIV-1/AIDS. In the past few years, novel nuclease-initiated genome editing tools have been developing rapidly, including ZFNs, TALENs, and the CRISPR/Cas9 system. These surgical knives, which can excise any genome, provide a great opportunity to eradicate the HIV-1 genome by targeting highly conserved regions of the HIV-1 long terminal repeats or essential viral genes. Given the time consuming and costly engineering of target-specific ZFNs and TALENs, the RNA-guided endonuclease Cas9 technology has emerged as a simpler and more versatile technology to allow permanent removal of integrated HIV-1 proviral DNA in eukaryotic cells, and hopefully animal models or human patients. The major unmet challenges of this approach at present include inefficient nuclease gene delivery, potential off-target cleavage, and cell-specific genome targeting. Nanoparticle or lentivirus-mediated delivery of next generation Cas9 technologies including nickase or RNA-guided FokI nuclease (RFN) will further improve the potential for genome editing to become a promising approach for curing HIV-1/AIDS. PMID:25716921

  15. Broad activation of latent HIV-1 in vivo.

    PubMed

    Barton, Kirston; Hiener, Bonnie; Winckelmann, Anni; Rasmussen, Thomas Aagaard; Shao, Wei; Byth, Karen; Lanfear, Robert; Solomon, Ajantha; McMahon, James; Harrington, Sean; Buzon, Maria; Lichterfeld, Mathias; Denton, Paul W; Olesen, Rikke; Østergaard, Lars; Tolstrup, Martin; Lewin, Sharon R; Søgaard, Ole Schmeltz; Palmer, Sarah

    2016-09-08

    The 'shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4(+) T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate measure of HIV-1 reservoir size. Our findings provide insights into the effects of panobinostat and vorinostat as LRAs for latent HIV-1.

  16. Platelets and HIV-1 infection: old and new aspects.

    PubMed

    Torre, Donato; Pugliese, Agostino

    2008-09-01

    In this review we summarize the data on interaction of platelets with HIV-1 infection. Thrombocytopenia is a common finding among HIV-1 infected patients; several combined factors contribute to low peripheral platelet counts, which are present during all the stages of the disease. In addition, a relationship between platelet count, plasma viral load and disease progression has been reported, and this shows the potential influence platelets may have on the natural history of HIV-1 disease. Several lines of evidence have shown that platelets are an integral part of inflammation, and can be also potent effector cells of innate immune response as well as of adaptive immunity. Thus, we rewieved the role of inflammatory cytokines, and chemokines as activators of platelets during HIV-1 infection. Moreover, platelets show a direct interaction with HIV-1 itself, through different pathogenic mechanisms as binding, engulfment, internalisation of HIV-1, playing a role in host defence during HIV-1 infection, by limiting viral spread and probably by inactivating viral particles. Platelets may also play an intriguing role on endothelial dysfunction present in HIV-1 infection, and this topic begins to receive systematic study, inasmuch as interaction between platelets and endothelial cells is important in the pathogenesis of atherosclerosis in HIV-1 infected patients, especially in those patients treated with antiretroviral drugs. Finally, this review attempts to better define the state of this emerging issue, to focus areas of potential clinical relevance, and to suggest several directions for future research.

  17. Transcriptional Bursting from the HIV-1 Promoter is a Significant Source of Stochastic Noise in HIV-1 Gene Expression

    SciTech Connect

    Singh, A; Razooky, B; Cox, Chris D.; Simpson, Michael L; Weinberger, Leor S.

    2010-01-01

    Analysis of noise in gene expression has proven a powerful approach for analyzing gene regulatory architecture. To probe the regulatory mechanisms controlling expression of HIV-1, we analyze noise in gene-expression from HIV-1 s long terminal repeat (LTR) promoter at different HIV-1 integration sites across the human genome. Flow cytometry analysis of GFP expression from the HIV-1 LTR shows high variability (noise) at each integration site. Notably, the measured noise levels are inconsistent with constitutive gene expression models. Instead, quantification of expression noise indicates that HIV-1 gene expression occurs through randomly timed bursts of activity from the LTR and that each burst generates an average of 2 10 mRNA transcripts before the promoter returns to an inactive state. These data indicate that transcriptional bursting can generate high variability in HIV-1 early gene products, which may critically influence the viral fate-decision between active replication and proviral latency.

  18. [Sensitivity of the COBAS AmpliScreen™ HIV-1 test v1.5 for HIV-1 detection].

    PubMed

    Gomez, Lucía P; Balangero, Marcos C; Castro, Gonzalo; Kademian, Silvia; Mangeaud, Arnaldo; Barbas, María G; Cudolá, Analía; de León, Juan F; Carrizo, Horacio; Gallego, Sandra V

    2014-01-01

    The introduction of nucleic acid amplification techniques (NAT) in blood banks was intended to reduce the residual risk of transfusion-transmitted infections. Co-circulation of a great diversity of HIV-1 variants in Argentina portrays the need to assess the sensitivity of serological and molecular assays available for their detection. In this study, we evaluated the sensitivity of the COBAS AmpliScreen™ HIV-1 Test, version 1.5 (Roche) for the detection of HIV-1 RNA in plasma samples of infected individuals from Argentina. The results of this study reveal that this technique has high sensitivity for the detection of HIV-1 RNA under assay conditions: using mini-pool testing, pools ≥ 50 RNA copies per ml achieved ≥ 92 % sensitivity, whereas in the standard procedure, samples ≥ 207 RNA copies/ml achieved 100 % sensitivity. Moreover, the COBAS AmpliScreen™ HIV-1 Test, version 1.5 (Roche) is suitable for detecting prevailing HIV-1 variants.

  19. Temperature increase prevails over acidification in gene expression modulation of amastigote differentiation in Leishmania infantum

    PubMed Central

    2010-01-01

    Background The extracellular promastigote and the intracellular amastigote stages alternate in the digenetic life cycle of the trypanosomatid parasite Leishmania. Amastigotes develop inside parasitophorous vacuoles of mammalian phagocytes, where they tolerate extreme environmental conditions. Temperature increase and pH decrease are crucial factors in the multifactorial differentiation process of promastigotes to amastigotes. Although expression profiling approaches for axenic, cell culture- and lesion-derived amastigotes have already been reported, the specific influence of temperature increase and acidification of the environment on developmental regulation of genes has not been previously studied. For the first time, we have used custom L. infantum genomic DNA microarrays to compare the isolated and the combined effects of both factors on the transcriptome. Results Immunofluorescence analysis of promastigote-specific glycoprotein gp46 and expression modulation analysis of the amastigote-specific A2 gene have revealed that concomitant exposure to temperature increase and acidification leads to amastigote-like forms. The temperature-induced gene expression profile in the absence of pH variation resembles the profile obtained under combined exposure to both factors unlike that obtained for exposure to acidification alone. In fact, the subsequent fold change-based global iterative hierarchical clustering analysis supports these findings. Conclusions The specific influence of temperature and pH on the differential regulation of genes described in this study and the evidence provided by clustering analysis is consistent with the predominant role of temperature increase over extracellular pH decrease in the amastigote differentiation process, which provides new insights into Leishmania physiology. PMID:20074347

  20. The Leishmania mexicana A600 genes are functionally required for amastigote replication.

    PubMed

    Murray, Angus S; Lynn, Miriam A; McMaster, W Robert

    2010-08-01

    Leishmania parasites, the causative agent of leishmaniasis, have a digenetic lifecycle consisting of the morphologically distinct insect vector stage (promastigote) and the mammalian infective amastigote stage. Differentiation of promastigotes to the amastigote stage involves significant morphological and biochemical changes, however, very few genes have been characterised as being differentially expressed in the two stages. The Leishmania A600 genes are one of the few gene families that exhibit stage-specific expression and, as such, they are of interest as potential virulent factors. In this study, we characterize the A600 family in several Leishmania species and investigate their role in amastigote differentiation and proliferation. Four open reading frames, A600-1, A600-2, A600-3, and A600-4, were identified at the multi-gene L. mexicana A600 locus via cloning and restriction mapping. Homology searching identified A600 homologues in other Leishmania species, L. major, L. braziliensis and L. infantum but not in the closely related Trypanosoma family. A targeted gene deletion approach was utilized to determine the cellular function of the L. mexicanaA600 genes. A600(-/-) promastigotes differentiated to axenic amastigotes in response to temperature shift and acidification of culture media, but showed significant growth arrest. Similarly, during in vitro macrophage infection studies, A600(-/-) promastigotes established an early infection, but were deficient in their ability to proliferate as intracellular amastigotes. The ability of A600(-/-) amastigotes to proliferate in mouse peritoneal macrophages was restored by re-introduction of the A600-1 gene, but not the A600-4 gene. The results from these experiments show that the A600-1 gene is essential for continued proliferation of amastigotes, and potentially for development of chronic leishmaniasis. Furthermore, these results suggest a potential role for the L. mexicana A600-deficient mutant as a vaccine candidate

  1. Higher frequency of HIV-1-specific T cell immune responses in African American children vertically infected with HIV-1.

    PubMed

    Sharp, Elizabeth R; Barbour, Jason D; Karlsson, R Karl; Jordan, Kimberly A; Sandberg, Johan K; Wiznia, Andrew; Rosenberg, Michael G; Nixon, Douglas F

    2005-11-15

    The progression of human immunodeficiency virus (HIV) disease and plasma levels of HIV may differ between racial groups. We compared HIV-specific T cell responses between vertically HIV-1-infected Hispanic and African American children. Subjects were matched for sex, age, viral load, and CD4(+) cell count in 18 pairs; T cell responses were measured by cytokine-enhanced interferon- gamma assay. Peripheral blood mononuclear cells were stimulated with HIV consensus peptides from Gag, Nef, and Tat. The influence of ethnicity, sex, age, viral load, and CD4(+) cell count on T cell responses was determined through linear regression analyses. After adjustment for CD4(+) count, age, and log(10) viral load, African American children demonstrated significantly higher Gag responses (average, 486 spot-forming cells higher; P=.01) than Hispanic children; this was significantly driven by robust responses in African American girls near the age of puberty, many of whom carried the human leukocyte antigen class I B*58 allele.

  2. Different Morphologies of Leishmania major Amastigotes with No Molecular Diversity in a Neglected Endemic Area of Zoonotic Cutaneous Leishmaniasis in Iran

    PubMed Central

    Spotin, Adel; Rouhani, Soheila; Ghaemmaghami, Parnazsadat; Haghighi, Ali; Zolfaghari, Mohammad Reza; Amirkhani, Aref; Farahmand, Mahin; Bordbar, Ali; Parvizi, Parviz

    2015-01-01

    Background: Molecular diversity of Leishmania major and its morphological changes have become a controversial issue among researchers. Some aspects of polymorphic shapes of amastigotes in clinical manifestations along with molecular variation were evaluated among suspected patients of some exceptional zoonotic cutaneous leishmaniasis locations in Northern Khuzestan, Southwestern Iran. Methods: Suspected patients (n = 165) were sampled in zoonotic cutaneous leishmaniasis foci over two consecutive years during 2012-2014. Prepared smears were stained, scaled and measured by ocular micrometer. DNA was extracted from smears; ITS-rDNA and Cytochrome b (Cyt b) markers were amplified, and PCR products were digested by BsuR1 restriction enzyme. Then the RFLP and sequencing were employed. Results: Only L. major was identified in patients containing regular amastigotes' shapes (oval or round) with a size of 2-4 µm in each of classical wet, dry, mixed lesions. Meanwhile, irregular shapes (spindle, pear, or cigarette) were observed separately in non-classical wet lesions with more than 4 µm. Interestingly, a few amastigotes with an external flagellum were observed in some lesions. All sequenced ITS-rDNA and Cyt b genes of L. major did not show any molecular variation (χ 2 P > 0.05), including only one common haplotype (GenBank access no. EF413075). Conclusion: Findings proved that unlike other endemic foci, there is not a meaningful correlation between phenotypic and genotypic features of L. major isolates. This study is considered as the first comprehensive report to incriminate morphometric shapes of L. major amastigotes, which enhances our knowledge concerning their relevance with various clinical appearances and genotypic traits. PMID:26081070

  3. HIV-1 and Human PEG10 Frameshift Elements Are Functionally Distinct and Distinguished by Novel Small Molecule Modulators

    PubMed Central

    Sleebs, Brad E.; Lackovic, Kurt; Parisot, John P.; Moss, Rebecca M.; Crowe-McAuliffe, Caillan; Mathew, Suneeth F.; Edgar, Christina D.; Kleffmann, Torsten; Tate, Warren P.

    2015-01-01

    Frameshifting during translation of viral or in rare cases cellular mRNA results in the synthesis of proteins from two overlapping reading frames within the same mRNA. In HIV-1 the protease, reverse transcriptase, and integrase enzymes are in a second reading frame relative to the structural group-specific antigen (gag), and their synthesis is dependent upon frameshifting. This ensures that a strictly regulated ratio of structural proteins and enzymes, which is critical for HIV-1 replication and viral infectivity, is maintained during protein synthesis. The frameshift element in HIV-1 RNA is an attractive target for the development of a new class of anti HIV-1 drugs. However, a number of examples are now emerging of human genes using −1 frameshifting, such as PEG10 and CCR5. In this study we have compared the HIV-1 and PEG10 frameshift elements and shown they have distinct functional characteristics. Frameshifting occurs at several points within each element. Moreover, frameshift modulators that were isolated by high-throughput screening of a library of 114,000 lead-like compounds behaved differently with the PEG10 frameshift element. The most effective compounds affecting the HIV-1 element enhanced frameshifting by 2.5-fold at 10 μM in two different frameshift reporter assay systems. HIV-1 protease:gag protein ratio was affected by a similar amount in a specific assay of virally-infected cultured cell, but the modulation of frameshifting of the first-iteration compounds was not sufficient to show significant effects on viral infectivity. Importantly, two compounds did not affect frameshifting with the human PEG10 element, while one modestly inhibited rather than enhanced frameshifting at the human element. These studies indicate that frameshift elements have unique characteristics that may allow targeting of HIV-1 and of other viruses specifically for development of antiviral therapeutic molecules without effect on human genes like PEG10 that use the same

  4. Archetype JC virus efficiently propagates in kidney-derived cells stably expressing HIV-1 Tat.

    PubMed

    Nukuzuma, Souichi; Kameoka, Masanori; Sugiura, Shigeki; Nakamichi, Kazuo; Nukuzuma, Chiyoko; Miyoshi, Isao; Takegami, Tsutomu

    2009-11-01

    Pathogenic JCV with rearranged regulatory regions (PML-type) causes PML, a demyelinating disease, in the brains of immunocompromised patients. On the other hand, archetype JCV persistently infecting the kidney is thought to be converted to PML-type virus during JCV replication in the infected host under immunosuppressed conditions. In addition, Tat protein, encoded by HIV-1, markedly enhances the expression of a reporter gene under control of the JCV late promoter. In order to examine the influence of Tat on JCV propagation, we used kidney-derived COS-7 cells, which only permit archetype JCV, and established COS-tat cells, which express HIV-1 Tat stably. We found that the extent of archetype JCV propagation in COS-tat cells is significantly greater than in COS-7 cells. On the other hand, COS-7 cells express SV40 T antigen, which is a strong stimulator of archetype JCV replication. The expression of SV40 T antigen was enhanced by HIV-1 Tat slightly according to real-time RT-PCR, this was not closely related to JCV replication in COS-tat cells. The efficiency of JCV propagation depended on the extent of expression of functional Tat. To our knowledge, this is the first report of increased production of archetype JCV in a culture system using cell lines stably expressing HIV-1 Tat. We propose here that COS-tat cells are a useful tool for studying the role of Tat in archetype JCV replication in the development of PML.

  5. Evaluation of Immune Survival Factors in Pediatric HIV-1 Infection

    PubMed Central

    SHEARER, WILLIAM T.; EASLEY, KIRK A.; GOLDFARB, JOHANNA; JENSON, HAL B.; ROSENBLATT, HOWARD M.; KOVACS, ANDREA; MCINTOSH, KENNETH

    2015-01-01

    Peripheral blood CD4+ and CD8+ T cells, CD19+/20+ B cells, and serum immunoglobulins (Igs) have been implicated as survival factors for pediatric HIV-1 infection. To determine which of these immune factors might be important in predicting survival, we studied HIV-1 vertically infected (HIV-1+) children over a 5-year period. Peripheral blood lymphocytes and Igs were measured in 298 HIV-1+ children, who were classified as survivors or nonsurvivors, and in 463 HIV-1 vertically exposed and noninfected (HIV-1–) children. Measurements of other possible survival factors were included in this study: albumin, hemoglobin, lactic dehydrogenase (LDH), and HIV-1 RNA levels. Survivors had significantly higher CD4+ T-cell, CD8+ T-cell, and CD19+/CD20+ B-cell counts and serum IgG levels, but lower serum IgA and IgM levels than nonsurvivors. Serum albumin and blood hemoglobin levels were higher, but serum LDH and HIV-1 RNA levels were lower in the survivors compared to non-survivors. In univariable analysis, factors affecting survival were baseline CD4+ T-cell and CD8+ T-cell counts, IgG, albumin, hemoglobin, LDH, and HIV-1 RNA (all p < 0.001). In multivariable analysis, high baseline CD4+ T-cell count, IgG and albumin levels, and low baseline HIV-1 RNA load remained important factors for survival. Serum IgG level has been identified as an immune factor that independently predicts survival, in addition to the already established CD4+ T-cell count. The HIV-1 RNA and serum albumin levels also predicted survival. PMID:11144332

  6. HIV-1 infection may be on the rise in Peru.

    PubMed

    The results of a national survey have indicated that "... HIV-1 infection is epidemic in Peru among groups at high risk of sexually and parenterally transmitted diseases," a multicenter group reported (AIDS 1996; 10: 1141-1145). Although the risk of infection appears to be very low in the general population, it may possibly be increasing, according to Dr. Michael C. McCarthy, US National Naval Medical Center in Bethesda, Maryland. McCarthy's group evaluated over 140,000 serum samples for antibodies to HIV-1 between January 1986 and December 1990 in Peru. HIV-1 antibody was detected in 26% of samples from homosexual men, 10% of samples from male sexually transmitted disease patients, and 13% of samples from drug users. 10% of the samples from hemophiliacs and unlicensed female prostitutes were positive for antibodies to HIV-1. In general, he concluded that the patterns of the HIV-1 epidemic in Peru are similar to those seen in Brazil and "... are also similar to initial transmission patterns of HIV-1 infection of North America." However, McCarthy also noted a substantial increase in the prevalence of HIV-1 infection between the beginning and the end of the survey period. Although there was a low prevalence of HIV-1 infection among military personnel and among women seen at prenatal clinics, a "low but rising prevalence of HIV-1 antibody" among military personnel points to a potential increase in the general population. "The fact that many HIV-1 antibody-positive men were married and reported bisexual behavior (28%) highlights the potential of this group to transmit HIV-1 to female partners," he added.

  7. Macrophage Inflammatory Protein-3 Alpha (MIP-3α)/CCL20 in HIV-1-Infected Individuals

    PubMed Central

    Aziz, Najib; Detels, Roger; Chang, L Cindy; Butch, Anthony W

    2016-01-01

    Objective Uncontrolled HIV infection progresses to the depletion of systemic and mucosal CD4 and AIDS. Early HIV infection may be associated with increases in the concentration of MIP-3α in the blood and gut fluids. MIP-3α/CCL20 is the only chemokine known to interact with CCR6 receptors which are expressed on immature dendritic cells and both effector and memory CD8+ and CD4+ T cells. The role and prognostic value of blood levels of MIP-3α in HIV-infected individuals has yet to be described. Methods We determined the serum levels of MIP-3α, and IFN-γ, in 167 HIV-1-infected and 27 HIV-1-uninfected men participating in the Multicenter AIDS Cohort Study (MACS). The blood biomarkers were measured using enzyme-linked immunosorbent assays (ELISA) and the cell phenotypes using flow cytometry. Results Median serum levels of MIP-3α in HIV-1-infected and uninfected men was significantly different (p<0.0001) and were 21.3 pg/mL and 6.4 pg/mL respectively. The HIV-1-infected men with CD4+ T cell count <200 cells/μL showed the highest median serum MIP-3α (23.1 pg/mL). Serum levels of MIP-3α in HIV-1 infected (n=167) were negatively correlated with absolute number of CD4+ T cell (p=0.01) and were positively correlated with CD38 molecules on CD8+ T cells (p=0.0002) and with serum levels of IFN-γ (0.006). Conclusion Serum levels of MIP-3α concomitantly increase with plasma levels of IFN-γ, CD38 expression on CD8+ T cells, and decreased of absolute CD4+ T cells in HIV-1-infected men. A higher blood level of MIP-3α may be representation of locally high level of MIP-3α and more recruitment of immature dendritic cell at site of infection. Involvement of CCR6/CCL20 axis and epithelial cells at the recto-colonel level may enhance sexual transmission of HIV-1 in MSM and may be useful as a prognostic marker in HIV-1-infection and AIDS. PMID:27617163

  8. Macrophage Inflammatory Protein-3 Alpha (MIP-3α)/CCL20 in HIV-1-Infected Individuals

    PubMed Central

    Aziz, Najib; Detels, Roger; Chang, L Cindy; Butch, Anthony W

    2016-01-01

    Objective Uncontrolled HIV infection progresses to the depletion of systemic and mucosal CD4 and AIDS. Early HIV infection may be associated with increases in the concentration of MIP-3α in the blood and gut fluids. MIP-3α/CCL20 is the only chemokine known to interact with CCR6 receptors which are expressed on immature dendritic cells and both effector and memory CD8+ and CD4+ T cells. The role and prognostic value of blood levels of MIP-3α in HIV-infected individuals has yet to be described. Methods We determined the serum levels of MIP-3α, and IFN-γ, in 167 HIV-1-infected and 27 HIV-1-uninfected men participating in the Multicenter AIDS Cohort Study (MACS). The blood biomarkers were measured using enzyme-linked immunosorbent assays (ELISA) and the cell phenotypes using flow cytometry. Results Median serum levels of MIP-3α in HIV-1-infected and uninfected men was significantly different (p<0.0001) and were 21.3 pg/mL and 6.4 pg/mL respectively. The HIV-1-infected men with CD4+ T cell count <200 cells/μL showed the highest median serum MIP-3α (23.1 pg/mL). Serum levels of MIP-3α in HIV-1 infected (n=167) were negatively correlated with absolute number of CD4+ T cell (p=0.01) and were positively correlated with CD38 molecules on CD8+ T cells (p=0.0002) and with serum levels of IFN-γ (0.006). Conclusion Serum levels of MIP-3α concomitantly increase with plasma levels of IFN-γ, CD38 expression on CD8+ T cells, and decreased of absolute CD4+ T cells in HIV-1-infected men. A higher blood level of MIP-3α may be representation of locally high level of MIP-3α and more recruitment of immature dendritic cell at site of infection. Involvement of CCR6/CCL20 axis and epithelial cells at the recto-colonel level may enhance sexual transmission of HIV-1 in MSM and may be useful as a prognostic marker in HIV-1-infection and AIDS.

  9. Striking HIV-1 Entry by Targeting HIV-1 gp41. But, Where Should We Target?

    PubMed Central

    Teixeira, Cátia; Barbault, Florent; Couesnon, Thierry; Gomes, José R. B.; Gomes, Paula; Maurel, François

    2016-01-01

    HIV-1 gp41 facilitates the viral fusion through a conformational switch involving the association of three C-terminal helices along the conserved hydrophobic grooves of three N-terminal helices coiled-coil. The control of these structural rearrangements is thought to be central to HIV-1 entry and, therefore, different strategies of intervention are being developed. Herewith, we describe a procedure to simulate the folding of an HIV-1 gp41 simplified model. This procedure is based on the construction of plausible conformational pathways, which describe protein transition between non-fusogenic and fusogenic conformations. The calculation of the paths started with 100 molecular dynamics simulations of the non-fusogenic conformation, which were found to converge to different intermediate states. Those presenting defined criteria were selected for separate targeted molecular dynamics simulations, subjected to a force constant imposing a movement towards the gp41 fusogenic conformation. Despite significant diversity, a preferred sequence of events emerged when the simulations were analyzed in terms of the formation, breakage and evolution of the contacts. We pointed out 29 residues as the most relevant for the movement of gp41; also, 2696 possible interactions were reduced to only 48 major interactions, which reveals the efficiency of the method. The analysis of the evolution of the main interactions lead to the detection of four main behaviors for those contacts: stable, increasing, decreasing and repulsive interactions. Altogether, these results suggest a specific small cavity of the HIV-1 gp41 hydrophobic groove as the preferred target to small molecules. PMID:26785380

  10. Exploitation of the Low Fidelity of Human Immunodeficiency Virus Type 1 (HIV-1) Reverse Transcriptase and the Nucleotide Composition Bias in the HIV-1 Genome To Alter the Drug Resistance Development of HIV

    PubMed Central

    Balzarini, Jan; Camarasa, Maria-José; Pérez-Pérez, Maria-Jesus; San-Félix, Ana; Velázquez, Sonsoles; Perno, Carlo-Federico; De Clercq, Erik; Anderson, John N.; Karlsson, Anna

    2001-01-01

    The RNA genome of the lentivirus human immunodeficiency virus type 1 (HIV-1) is significantly richer in adenine nucleotides than the statistically equal distribution of the four different nucleotides that is expected. This compositional bias may be due to the guanine-to-adenine (G→A) nucleotide hypermutation of the HIV genome, which has been explained by dCTP pool imbalances during reverse transcription. The adenine nucleotide bias together with the poor fidelity of HIV-1 reverse transcriptase markedly enhances the genetic variation of HIV and may be responsible for the rapid emergence of drug-resistant HIV-1 strains. We have now attempted to counteract the normal mutational pattern of HIV-1 in response to anti-HIV-1 drugs by altering the endogenous deoxynucleoside triphosphate pool ratios with antimetabolites in virus-infected cell cultures. We showed that administration of these antimetabolic compounds resulted in an altered drug resistance pattern due to the reversal of the predominant mutational flow of HIV (G→A) to an adenine-to-guanine (A→G) nucleotide pattern in the intact HIV-1-infected lymphocyte cultures. Forcing the virus to change its inherent nucleotide bias may lead to better control of viral drug resistance development. PMID:11390579

  11. Quantitative HIV-1 proviral DNA detection: a multicentre analysis.

    PubMed

    De Rossi, Anita; Zanchetta, Marisa; Vitone, Francesca; Antonelli, Guido; Bagnarelli, Patrizia; Buonaguro, Luigi; Capobianchi, Maria Rosaria; Clementi, Massimo; Abbate, Isabella; Canducci, Filippo; Monachetti, Alessia; Riva, Elisabetta; Rozera, Gabriella; Scagnolari, Carolina; Tagliamonte, Maria; Re, Maria Carla

    2010-10-01

    Despite the widespread use of molecular biology techniques, standardized methods for the measurement of HIV-1 proviral DNA are currently lacking and several discordant results are still present in different studies. To assess the clinical meaning of the proviral DNA load, a study group comprising seven different laboratories was set up to standardize a HIV-1 proviral DNA quantification method able to assess the DNA proviral load of the most relevant circulating HIV-1 subtypes. Reference samples (24 cellular samples infected with HIV-1 clade B, and 40 samples of peripheral blood mononuclear cells containing different concentrations of plasmids expressing different HIV-1 clades) were distributed and tested blindly. All laboratories employed hTERT gene as housekeeping gene and primers within the gag gene to quantify different HIV-1 clades. Inter-laboratory results did not differ statistically but showed only minor variations concerning HIV-1 DNA amounts and different HIV clades, with a good agreement among the laboratories participating in the study. Since test standardization represents a key step for future application in clinical practice, further studies of the patients' samples are in progress to establish the real meaning and utility of the proviral DNA load for clinical management of HIV-1 infected patients. PMID:21213587

  12. Iron chelators ICL670 and 311 inhibit HIV-1 transcription

    SciTech Connect

    Debebe, Zufan; Ammosova, Tatyana; Jerebtsova, Marina; Kurantsin-Mills, Joseph; Niu, Xiaomei; Charles, Sharroya; Richardson, Des R.; Ray, Patricio E.; Gordeuk, Victor R.; Nekhai, Sergei

    2007-10-25

    HIV-1 replication is induced by an excess of iron and iron chelation by desferrioxamine (DFO) inhibits viral replication by reducing proliferation of infected cells. Treatment of cells with DFO and 2-hydroxy-1-naphthylaldehyde isonicotinoyl hydrazone (311) inhibit expression of proteins that regulate cell-cycle progression, including cycle-dependent kinase 2 (CDK2). Our recent studies showed that CDK2 participates in HIV-1 transcription and viral replication suggesting that inhibition of CDK2 by iron chelators might also affect HIV-1 transcription. Here we evaluated the effect of a clinically approved orally effective iron chelator, 4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid (ICL670) and 311 on HIV-1 transcription. Both ICL670 and 311 inhibited Tat-induced HIV-1 transcription in CEM-T cells, 293T and HeLa cells. Neither ICL670 nor 311 induced cytotoxicity at concentrations that inhibited HIV-1 transcription. The chelators decreased cellular activity of CDK2 and reduced HIV-1 Tat phosphorylation by CDK2. Neither ICL670A or 311 decreased CDK9 protein level but significantly reduced association of CDK9 with cyclin T1 and reduced phosphorylation of Ser-2 residues of RNA polymerase II C-terminal domain. In conclusion, our findings add to the evidence that iron chelators can inhibit HIV-1 transcription by deregulating CDK2 and CDK9. Further consideration should be given to the development of iron chelators for future anti-retroviral therapeutics.

  13. [A new unique HIV-1 recombinant form detected in Belarus].

    PubMed

    Eremin, V F; Gasich, E L; Sosinovich, S V

    2012-01-01

    Republican Research-and-Practical Center for Epidemiology and Microbiology, Ministry of Health of Belarus, Minsk The paper presents data on the molecular genetic characteristics of a new HIV-1 recombinant form. The study has shown that the virus is referred to as HIV-1 subtype B in terms of the gag gene and HIV-1 subtype A in terms of the pol and env genes. At the same time the new isolate is closer, in terms of the gag gene, to the HIV-1 DQ207943 strain isolated in Georgia, in terms of the pol gene, to the HIV-1 AF413987.1 strain isolated in Ukraine and, in terms of the env gene to the HIV-1 AY500393 strain isolated in Russia. Thus, the described new HIV-1 recombinant form has the following structure: BgagApolAenv. The gag, pol, and env gene sequences from the new unique HIV-1 recombinant form have been registered in the international database EMBL/Genbank/DDBJ under accession numbers FR775442.1, FN995656.1, and FR775443.1.

  14. Monocytotropic human immunodeficiency virus type 1 (HIV-1) variants detectable in all stages of HIV-1 infection lack T-cell line tropism and syncytium-inducing ability in primary T-cell culture.

    PubMed Central

    Schuitemaker, H; Kootstra, N A; de Goede, R E; de Wolf, F; Miedema, F; Tersmette, M

    1991-01-01

    We previously demonstrated a correlation between the presence of syncytium-inducing (SI) human immunodeficiency virus type 1 (HIV-1) variants showing tropism for cell line H9 and the occurrence of rapid CD4 cell decline and progression to AIDS. In contrast, in stable asymptomatic individuals, we detected only isolates with low replication rates that were non-syncytium-inducing (NSI) and nontropic for the H9 cell line. Here, we investigated the monocytotropism of established HIV-1 isolates with a panel of isolates and with biological HIV-1 clones with distinct phenotypes. Moreover, the prevalence and biological phenotypes of monocytotropic HIV-1 variants in the course of HIV-1 infection were analyzed in comparative primary isolation studies on peripheral blood lymphocytes (PBL) and monocyte-derived macrophages (MDM). In cell-free infection studies with MDM from eight blood donors, 13 of 17 NSI isolates but only 4 of 14 SI isolates were able to infect MDM. NSI isolates also infected significantly more different donors than SI variants (median, 3 of 8 versus 0 of 8). This enhanced monocytotropism of NSI isolates was confirmed in experiments with biological HIV-1 clones with distinct phenotypes recovered from the same donor. To investigate the prevalence and biological phenotypes of monocytotropic variants in different stages of HIV-1 infection, sequential isolates from peripheral blood mononuclear cell samples from nine asymptomatic individuals, five of whom progressed to AIDS and seven of whom had a known time of seroconversion, were recovered by cocultivation with both PBL and MDM. Monocytotropic variants were obtained from 37 of 42 time points. All monocytotropic variants were NSI in PBL culture and non-T-cell-line tropic, even when SI, T-cell-line-tropic HIV-1 variants could be recovered from the same patient sample by cocultivation with PBL. We conclude that monocytotropic HIV-1 variants mostly have an NSI phenotype in PBL and, in contrast to SI variants, are

  15. Multifarious immunotherapeutic approaches to cure HIV-1 infection.

    PubMed

    Imami, Nesrina; Herasimtschuk, Anna A

    2015-01-01

    Immunotherapy in the context of treated HIV-1 infection aims to improve immune responses to achieve better control of the virus. To date, multifaceted immunotherapeutic approaches have been shown to reduce immune activation and increase CD4 T-lymphocyte counts, further to the effects of antiretroviral therapy alone, in addition to improving HIV-1-specific T-cell responses. While sterilizing cure of HIV-1 would involve elimination of all replication-competent virus, a functional cure in which the host has long-lasting control of viral replication may be more feasible. In this commentary, we discuss novel strategies aimed at targeting the latent viral reservoir with cure of HIV-1 infection being the ultimate goal, an achievement that would have considerable impact on worldwide HIV-1 infection.

  16. Which therapeutic strategy will achieve a cure for HIV-1?

    PubMed

    Cillo, Anthony R; Mellors, John W

    2016-06-01

    Strategies to achieve a cure for HIV-1 infection can be broadly classified into three categories: eradication cure (elimination of all viral reservoirs), functional cure (immune control without reservoir eradication), or a hybrid cure (reservoir reduction with improved immune control). The many HIV-1 cure strategies being investigated include modification of host cells to resist HIV-1, engineered T cells to eliminate HIV-infected cells, broadly HIV-1 neutralizing monoclonal antibodies, and therapeutic vaccination, but the 'kick and kill' strategy to expose latent HIV-1 with latency reversing agents (LRAs) and kill the exposed cells through immune effector functions is currently the most actively pursued. It is unknown, however, whether LRAs can deplete viral reservoirs in vivo or whether current LRAs are sufficiently safe for clinical use.

  17. Modeling HIV-1 Mucosal Transmission and Prevention in Humanized Mice.

    PubMed

    Veselinovic, Milena; Charlins, Paige; Akkina, Ramesh

    2016-01-01

    The new generation humanized mice (hu-mice) that permit continuous de novo generation of human hematopoietic cells have led to novel strategies in studying HIV-1 pathogenesis, prevention and therapies. HIV-1 infection of hu-mice results in chronic viremia and CD4+ T cell loss, thus mimicking key aspects of the disease progression. In addition, the new generation hu-mice are permissive for HIV-1 sexual transmission by vaginal and rectal routes thus allowing in vivo efficacy testing of new anti-HIV-1 drugs for prevention. Two leading models are currently being used, namely the hu-HSC mice and the BLT mice. Here we describe the methodology for generating both hu-HSC and BLT mice and their use in the study of HIV-1 transmission and prevention of infection by topical and oral administration of anti-retroviral drugs. Practical aspects of the methodologies are emphasized.

  18. HIV-1 and interferons: who's interfering with whom?

    PubMed

    Doyle, Tomas; Goujon, Caroline; Malim, Michael H

    2015-07-01

    The ability of interferons (IFNs) to inhibit HIV-1 replication in cell culture models has long been recognized, and the therapeutic administration of IFNα to HIV-1-infected patients who are not receiving antiretroviral therapy produces a clear but transient decrease in plasma viral load. Conversely, studies of chronic HIV-1 infection in humans and SIV-infected animal models of AIDS show positive correlations between elevated plasma levels of IFNs, increased expression of IFN-stimulated genes (ISGs), biomarkers of inflammation and disease progression. In this Review, we discuss the evidence that IFNs can control HIV-1 replication in vivo and debate the controversial role of IFNs in promoting the pathological sequelae of chronic HIV-1 infection.

  19. Transmitted drug resistance in nonsubtype B HIV-1 infection

    PubMed Central

    Chan, Philip A; Kantor, Rami

    2009-01-01

    HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and limited treatment options and, therefore, is an important concern. Evaluation of reported transmitted drug resistance (TDR) is challenging owing to varying definitions and study designs, and is further complicated by HIV-1 subtype diversity. In this article, we discuss the importance of various mutation lists for TDR definition, summarize TDR in nonsubtype B HIV-1 and highlight TDR reporting and interpreting challenges in the context of HIV-1 diversity. When examined carefully, TDR in HIV-1 non-B protease and reverse transcriptase is still relatively low in most regions. Whether it will increase with time and therapy access, as observed in subtype-B-predominant regions, remains to be determined. PMID:20161523

  20. HIV-1 infection, microenvironment and endothelial cell dysfunction.

    PubMed

    Mazzuca, Pietro; Caruso, Arnaldo; Caccuri, Francesca

    2016-09-01

    HIV-1 promotes a generalized immune activation that involves the main targets of HIV-1 infection but also cells that are not sensitive to viral infection. ECs display major dysfunctions in HIV+ patients during long-standing viral infection that persist even in the current cART era, in which new-generation drugs have reduced dysmetabolic side effects and successfully impeded viral replication. In vivo studies have failed to demonstrate the presence of replicating virus in ECs suggesting that a direct role of the virus is unlikely, and implying that the mechanism accounting for vascular dysfunction may rely on the indirect action of molecules released in the microenvironment by HIV-1-infected cells. This article reviews the current understanding of how HIV-1 infection can contribute to vascular dysfunction. In particular, we discuss the emerging role played by different HIV-1 proteins in driving inflammation and EC dysregulation, and highlight the need to target them for therapeutic benefit. PMID:27602413

  1. HIV-1 differentially modulates autophagy in neurons and astrocytes.

    PubMed

    Mehla, Rajeev; Chauhan, Ashok

    2015-08-15

    Autophagy, a lysosomal degradative pathway that maintains cellular homeostasis, has emerged as an innate immune defense against pathogens. The role of autophagy in the deregulated HIV-infected central nervous system (CNS) is unclear. We have found that HIV-1-induced neuro-glial (neurons and astrocytes) damage involves modulation of the autophagy pathway. Neuro-glial stress induced by HIV-1 led to biochemical and morphological dysfunctions. X4 HIV-1 produced neuro-glial toxicity coupled with suppression of autophagy, while R5 HIV-1-induced toxicity was restricted to neurons. Rapamycin, a specific mTOR inhibitor (autophagy inducer) relieved the blockage of the autophagy pathway caused by HIV-1 and resulted in neuro-glial protection. Further understanding of the regulation of autophagy by cytokines and chemokines or other signaling events may lead to recognition of therapeutic targets for neurodegenerative diseases.

  2. Low-level detection and quantitation of cellular HIV-1 DNA and 2-LTR circles using droplet digital PCR.

    PubMed

    Henrich, Timothy J; Gallien, Sebastien; Li, Jonathan Z; Pereyra, Florencia; Kuritzkes, Daniel R

    2012-12-01

    Droplet digital PCR (ddPCR) is an emerging nucleic acid detection method that provides absolute quantitations of target sequences without relying on the use of standard curves. The ability of ddPCR to detect and quantitate total HIV-1 DNA and 2-LTR circles from a panel of patients on and off antiviral therapy was evaluated compared to established real-time (RT)-PCR methods. To calculate the dynamic range of ddPCR for HIV-1 DNA and 2-LTR circles, serial dilutions of DNA amplicons or episomes were determined by ddPCR as well as with RT-PCR. HIV-1 DNA from 3 viremic patients and 4 patients on suppressive antiretroviral therapy, and 2-LTR circles from 3 patients with low-level viremia were also quantitated. Copy numbers determined by ddPCR of serial dilutions of HIV-1 or human CCR5 DNA amplicon standards were comparable to nominal input copy number. The sensitivity of ddPCR to detect HIV-1 or CCR5 DNA was similar to that of RT-PCR. Low levels of 2-LTR circles were detected in samples from all 3 patients by both ddPCR and RT-PCR. ddPCR is a promising novel technology for the study of HIV-1 reservoirs and persistence, but further optimization of this novel technology would enhance the detection of very low-level viral genetic targets. PMID:22974526

  3. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection.

    PubMed

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-07-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca(2+) influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4(+) T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis.

  4. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection

    PubMed Central

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-01-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca2+ influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4+ T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis. PMID:27383627

  5. The G1/S Specific Cyclin D2 Is a Regulator of HIV-1 Restriction in Non-proliferating Cells

    PubMed Central

    Badia, Roger; Pujantell, Maria; Riveira-Muñoz, Eva; Puig, Teresa; Torres-Torronteras, Javier; Martí, Ramón; Clotet, Bonaventura; Ampudia, Rosa M.; Ballana, Ester

    2016-01-01

    Macrophages are a heterogeneous cell population strongly influenced by differentiation stimuli that become susceptible to HIV-1 infection after inactivation of the restriction factor SAMHD1 by cyclin-dependent kinases (CDK). Here, we have used primary human monocyte-derived macrophages differentiated through different stimuli to evaluate macrophage heterogeneity on cell activation and proliferation and susceptibility to HIV-1 infection. Stimulation of monocytes with GM-CSF induces a non-proliferating macrophage population highly restrictive to HIV-1 infection, characterized by the upregulation of the G1/S-specific cyclin D2, known to control early steps of cell cycle progression. Knockdown of cyclin D2, enhances HIV-1 replication in GM-CSF macrophages through inactivation of SAMHD1 restriction factor by phosphorylation. Co-immunoprecipitation experiments show that cyclin D2 forms a complex with CDK4 and p21, a factor known to restrict HIV-1 replication by affecting the function of the downstream cascade that leads to SAMHD1 deactivation. Thus, we demonstrate that cyclin D2 acts as regulator of cell cycle proteins affecting SAMHD1-mediated HIV-1 restriction in non-proliferating macrophages. PMID:27541004

  6. Editing of HIV-1 RNA by the double-stranded RNA deaminase ADAR1 stimulates viral infection

    PubMed Central

    Doria, Margherita; Neri, Francesca; Gallo, Angela; Farace, Maria Giulia; Michienzi, Alessandro

    2009-01-01

    Adenosine deaminases that act on dsRNA (ADARs) are enzymes that target double-stranded regions of RNA converting adenosines into inosines (A-to-I editing) thus contributing to genome complexity and fine regulation of gene expression. It has been described that a member of the ADAR family, ADAR1, can target viruses and affect their replication process. Here we report evidence showing that ADAR1 stimulates human immuno deficiency virus type 1 (HIV-1) replication by using both editing-dependent and editing-independent mechanisms. We show that over-expression of ADAR1 in HIV-1 producer cells increases viral protein accumulation in an editing-independent manner. Moreover, HIV-1 virions generated in the presence of over-expressed ADAR1 but not an editing-inactive ADAR1 mutant are released more efficiently and display enhanced infectivity, as demonstrated by challenge assays performed with T cell lines and primary CD4+ T lymphocytes. Finally, we report that ADAR1 associates with HIV-1 RNAs and edits adenosines in the 5′ untranslated region (UTR) and the Rev and Tat coding sequence. Overall these results suggest that HIV-1 has evolved mechanisms to take advantage of specific RNA editing activity of the host cell and disclose a stimulatory function of ADAR1 in the spread of HIV-1. PMID:19651874

  7. Virion encapsidated HIV-1 Vpr induces NFAT to prime non-activated T cells for productive infection.

    PubMed

    Höhne, Kristin; Businger, Ramona; van Nuffel, Anouk; Bolduan, Sebastian; Koppensteiner, Herwig; Baeyens, Ann; Vermeire, Jolien; Malatinkova, Eva; Verhasselt, Bruno; Schindler, Michael

    2016-07-01

    The majority of T cells encountered by HIV-1 are non-activated and do not readily allow productive infection. HIV-1 Vpr is highly abundant in progeny virions, and induces signalling and HIV-1 LTR transcription. We hence hypothesized that Vpr might be a determinant of non-activated T-cell infection. Virion-delivered Vpr activated nuclear factor of activated T cells (NFAT) through Ca(2+) influx and interference with the NFAT export kinase GSK3β. This leads to NFAT translocation and accumulation within the nucleus and was required for productive infection of unstimulated primary CD4(+) T cells. A mutagenesis approach revealed correlation of Vpr-mediated NFAT activation with its ability to enhance LTR transcription and mediate cell cycle arrest. Upon NFAT inhibition, Vpr did not augment resting T-cell infection, and showed reduced G2/M arrest and LTR transactivation. Altogether, Vpr renders unstimulated T cells more permissive for productive HIV-1 infection and stimulates activation of productively infected as well as virus-exposed T cells. Therefore, it could be involved in the establishment and reactivation of HIV-1 from viral reservoirs and might have an impact on the levels of immune activation, which are determinants of HIV-1 pathogenesis. PMID:27383627

  8. GSK3β-Activation is a Point of Convergence for HIV-1 and Opiate-Mediated Interactive Neurotoxicity

    PubMed Central

    Masvekar, Ruturaj R.; El-Hage, Nazira; Hauser, Kurt F.; Knapp, Pamela E.

    2015-01-01

    Infection of the CNS with HIV-1 occurs rapidly after primary peripheral infection. HIV-1 can induce a wide range of neurological deficits, collectively known as HIV-1-associated neurocognitive disorders. Our previous work has shown that the selected neurotoxic effects induced by individual viral proteins, Tat and gp120, and by HIV+ supernatant are enhanced by co-exposure to morphine. This mimics co-morbid neurological effects observed in opiate-abusing HIV+ patients. Although there is a correlation between opiate drug abuse and progression of HIV-1-associated neurocognitive disorders, the mechanisms underlie interactions between HIV-1 and opiates remain obscure. Previous studies have shown that HIV-1 induces neurotoxic effects through abnormal activation of GSK3β. Interestingly, expression of GSK3β has shown to be elevated in brains of young opiate abusers indicating that GSK3β is also linked to neuropathology seen with opiate abusing patients. Thus, we hypothesize that GSK3β activation is a point of convergence for HIV- and opiate-mediated interactive neurotoxic effects. Neuronal cultures were treated with supernatant from HIV-1SF162-infected THP-1 cells, in the presence or absence of morphine and GSK3β inhibitors. Our results show that GSK3β inhibitors, including valproate and small molecule inhibitors, significantly reduce HIV-1-mediated neurotoxic outcomes, and also negate interactions with morphine that result in cell death, suggesting that GSK3β-activation is an important point of convergence and a potential therapeutic target for HIV- and opiate-mediated neurocognitive deficits. PMID:25616162

  9. Effective Cytotoxic T Lymphocyte Targeting of Persistent HIV-1 during Antiretroviral Therapy Requires Priming of Naive CD8+ T Cells

    PubMed Central

    Smith, Kellie N.; Mailliard, Robbie B.; Piazza, Paolo A.; Fischer, Will; Korber, Bette T.; Fecek, Ronald J.; Ratner, Deena; Gupta, Phalguni; Mullins, James I.

    2016-01-01

    ABSTRACT Curing HIV-1 infection will require elimination of persistent cellular reservoirs that harbor latent virus in the face of combination antiretroviral therapy (cART). Proposed immunotherapeutic strategies to cure HIV-1 infection include enhancing lysis of these infected cells by cytotoxic T lymphocytes (CTL). A major challenge in this strategy is overcoming viral immune escape variants that have evaded host immune control. Here we report that naive CD8+ T cells from chronic HIV-1-infected participants on long-term cART can be primed by dendritic cells (DC). These DC must be mature, produce high levels of interleukin 12p70 (IL-12p70), be responsive to CD40 ligand (CD40L), and be loaded with inactivated, autologous HIV-1. These DC-primed CD8+ T cell responders produced high levels of gamma interferon (IFN-γ) in response to a broad range of both conserved and variable regions of Gag and effectively killed CD4+ T cell targets that were either infected with the autologous latent reservoir-associated virus or loaded with autologous Gag peptides. In contrast, HIV-1-specific memory CD8+ T cells stimulated with autologous HIV-1-loaded DC produced IFN-γ in response to a narrow range of conserved and variable Gag peptides compared to the primed T cells and most notably, displayed significantly lower cytolytic function. Our findings highlight the need to selectively induce new HIV-1-specific CTL from naive precursors while avoiding activation of existing, dysfunctional memory T cells in potential curative immunotherapeutic strategies for HIV-1 infection. PMID:27247230

  10. Recent Advances in Lentiviral Vaccines for HIV-1 Infection.

    PubMed

    Norton, Thomas D; Miller, Elizabeth A

    2016-01-01

    The development of an effective HIV vaccine to prevent and/or cure HIV remains a global health priority. Given their central role in the initiation of adaptive immune responses, dendritic cell (DC)-based vaccines are being increasingly explored as immunotherapeutic strategies to enhance HIV-specific T cells in infected individuals and, thus, promote immune responses that may help facilitate a functional cure. HIV-1-based lentiviral (LV) vectors have inherent advantages as DC vaccine vectors due to their ability to transduce non-dividing cells and integrate into the target cell genomic DNA, allowing for expression of encoded antigens over the lifespan of the cell. Moreover, LV vectors may express additional immunostimulatory and immunoregulatory proteins that enhance DC function and direct antigen-specific T cells responses. Recent basic and clinical research efforts have broadened our understanding of LV vectors as DC-based vaccines. In this review, we provide an overview of the pre-clinical and clinical LV vector vaccine studies for treating HIV to date. We also discuss advances in LV vector designs that have enhanced DC transduction efficiency, target cell specificity, and immunogenicity, and address potential safety concerns regarding LV vector-based vaccines. PMID:27446074

  11. Recent Advances in Lentiviral Vaccines for HIV-1 Infection

    PubMed Central

    Norton, Thomas D.; Miller, Elizabeth A.

    2016-01-01

    The development of an effective HIV vaccine to prevent and/or cure HIV remains a global health priority. Given their central role in the initiation of adaptive immune responses, dendritic cell (DC)-based vaccines are being increasingly explored as immunotherapeutic strategies to enhance HIV-specific T cells in infected individuals and, thus, promote immune responses that may help facilitate a functional cure. HIV-1-based lentiviral (LV) vectors have inherent advantages as DC vaccine vectors due to their ability to transduce non-dividing cells and integrate into the target cell genomic DNA, allowing for expression of encoded antigens over the lifespan of the cell. Moreover, LV vectors may express additional immunostimulatory and immunoregulatory proteins that enhance DC function and direct antigen-specific T cells responses. Recent basic and clinical research efforts have broadened our understanding of LV vectors as DC-based vaccines. In this review, we provide an overview of the pre-clinical and clinical LV vector vaccine studies for treating HIV to date. We also discuss advances in LV vector designs that have enhanced DC transduction efficiency, target cell specificity, and immunogenicity, and address potential safety concerns regarding LV vector-based vaccines. PMID:27446074

  12. Leishmania amastigote target antigens: the challenge of a stealthy intracellular parasite.

    PubMed

    McMahon-Pratt, D; Kima, P E; Soong, L

    1998-01-01

    The development of a defined molecular vaccine against leishmaniasis involves the determination of candidate molecules that elicit protection against infection. As the amastigote stage is the developmental form found in the infected mammalian host, molecules specific to or upregulated in this stage represent potential antigenic vaccine targets. Diane McMahon-Pratt, Peter Kima and Lynn Soong summarize experiments which indicate that immunization with molecules upregulated in the amastigote stage can provide effective protection against infection. In the immunized host, both CD4(+) and CD8(+) T cells appear to be crucial to protection. Studies of antigen presentation of Leishmania-infected macrophages indicate that the amastigote stage can sequester endogenous leishmanial antigen from the major histocompatability complex (MHC) class II presentation pathway. However, evidence indicates that MHC class I presentation may be sustained in the infected macrophage. The effect of these findings on the design of a leishmanial vaccine are considered.

  13. Making an anti-amastigote vaccine for visceral leishmaniasis: rational, update and perspectives.

    PubMed

    Fernandes, Ana Paula; Coelho, Eduardo Antonio Ferraz; Machado-Coelho, George Luiz Lins; Grimaldi, Gabriel; Gazzinelli, Ricardo Tostes

    2012-08-01

    Visceral leishmaniasis is a major health problem in Latina America, as well as the Mediterranean region of Europe and Asia. We aimed to develop a vaccine against visceral leishmaniasis targeting the intracellular amastigotes, which is the parasite stage that persists throughout infections with Leishmania parasites. With this in mind, we identified an amastigote specific antigen (A2) that contains an immunogenic epitope for CD4+ T helper (Th) cells and multiple repetitive units encoding CD8+ cytotoxic T lymphocyte (CTL) epitopes. Vaccine formulations containing the recombinant A2 associated with saponin, alum and IL-12 or expressed by attenuated adenovirus were shown to be protective in mice, dogs and nonhuman-primates. We are currently identifying novel amastigote specific immunogenic proteins that could be aggregated to A2 to further improve the level of vaccine-induced cell-mediated immunity and protection against visceral leishmaniasis. PMID:22698479

  14. Making an anti-amastigote vaccine for visceral leishmaniasis: rational, update and perspectives.

    PubMed

    Fernandes, Ana Paula; Coelho, Eduardo Antonio Ferraz; Machado-Coelho, George Luiz Lins; Grimaldi, Gabriel; Gazzinelli, Ricardo Tostes

    2012-08-01

    Visceral leishmaniasis is a major health problem in Latina America, as well as the Mediterranean region of Europe and Asia. We aimed to develop a vaccine against visceral leishmaniasis targeting the intracellular amastigotes, which is the parasite stage that persists throughout infections with Leishmania parasites. With this in mind, we identified an amastigote specific antigen (A2) that contains an immunogenic epitope for CD4+ T helper (Th) cells and multiple repetitive units encoding CD8+ cytotoxic T lymphocyte (CTL) epitopes. Vaccine formulations containing the recombinant A2 associated with saponin, alum and IL-12 or expressed by attenuated adenovirus were shown to be protective in mice, dogs and nonhuman-primates. We are currently identifying novel amastigote specific immunogenic proteins that could be aggregated to A2 to further improve the level of vaccine-induced cell-mediated immunity and protection against visceral leishmaniasis.

  15. HIV-1 Vpr reactivates latent HIV-1 provirus by inducing depletion of class I HDACs on chromatin

    PubMed Central

    Romani, Bizhan; Kamali Jamil, Razieh; Hamidi-Fard, Mojtaba; Rahimi, Pooneh; Momen, Seyed Bahman; Aghasadeghi, Mohammad Reza; Allahbakhshi, Elham

    2016-01-01

    HIV-1 Vpr is an accessory protein that induces proteasomal degradation of multiple proteins. We recently showed that Vpr targets class I HDACs on chromatin for proteasomal degradation. Here we show that Vpr induces degradation of HDAC1 and HDAC3 in HIV-1 latently infected J-Lat cells. Degradation of HDAC1 and HDAC3 was also observed on the HIV-1 LTR and as a result, markers of active transcription were recruited to the viral promoter and induced viral activation. Knockdown of HDAC1 and HDAC3 activated the latent HIV-1 provirus and complementation with HDAC3 inhibited Vpr-induced HIV-1 reactivation. Viral reactivation and degradation of HDAC1 and HDAC3 was conserved among Vpr proteins of HV-1 group M. Serum Vpr isolated from patients or the release of virion-incorporated Vpr from viral lysates also activated HIV-1 in latently infected cell lines and PBMCs from HIV-1 infected patients. Our results indicate that Vpr counteracts HIV-1 latency by inducing proteasomal degradation of HDAC1 and 3 leading to reactivation of the viral promoter. PMID:27550312

  16. HIV-1-infected macrophages induce astrogliosis by SDF-1{alpha} and matrix metalloproteinases

    SciTech Connect

    Okamoto, Mika; Wang, Xin; Baba, Masanori . E-mail: baba@m.kufm.kagoshima-u.ac.jp

    2005-11-04

    Brain macrophages/microglia and astrocytes are known to be involved in the pathogenesis of HIV-1-associated dementia (HAD). To clarify their interaction and contribution to the pathogenesis, HIV-1-infected or uninfected macrophages were used as a model of brain macrophages/microglia, and their effects on human astrocytes in vitro were examined. The culture supernatants of HIV-1-infected or uninfected macrophages induced significant astrocyte proliferation, which was annihilated with a neutralizing antibody to stromal cell-derived factor (SDF)-1{alpha} or a matrix metalloproteinase (MMP) inhibitor. In these astrocytes, CXCR4, MMP, and tissue inhibitors of matrix metalloproteinase mRNA expression and SDF-1{alpha} production were significantly up-regulated. The supernatants of infected macrophages were always more effective than those of uninfected cells. Moreover, the enhanced production of SDF-1{alpha} was suppressed by the MMP inhibitor. These results indicate that the activated and HIV-1-infected macrophages can indirectly induce astrocyte proliferation through up-regulating SDF-1{alpha} and MMP production, which implies a mechanism of astrogliosis in HAD.

  17. HIV1-viral protein R (Vpr) mutations: associated phenotypes and relevance for clinical pathologies.

    PubMed

    Soares, Rui; Rocha, Graça; Meliço-Silvestre, António; Gonçalves, Teresa

    2016-09-01

    Over the last 30 years, research into HIV has advanced the knowledge of virus genetics and the development of efficient therapeutic strategies. HIV-1 viral protein R (Vpr) is a specialized and multifunctional protein that plays important roles at multiple stages of the HIV-1 viral life cycle. This protein interacts with a number of cellular and viral proteins and with multiple activities including nuclear transport of the pre-integration complex (PIC) to the nucleus, transcriptional activation, cell cycle arrest at G2/M transition phase and induction of cell death via apoptosis. Specifically, Vpr has been shown to control many host cell functions through a variety of biological processes and by interaction with several cellular pathways. The different functions of Vpr may enhance viral replication and impair the immune system in HIV-1 infected patients. Importantly, functional defects induced by mutations in the Vpr protein correlate with slow disease progression of HIV-infected patients. Vpr is also associated with other concomitant pathologies developed by these patients, which may lead it to be considered as a potential novel therapeutic target. This review will focus on HIV-1 Vpr, mainly on the importance of its structural mutations on the progression of HIV infection, associated phenotypes and relevance for clinical pathologies. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Interfacial cavity filling to optimize CD4-mimetic miniprotein interactions with the HIV-1 surface protein

    PubMed Central

    Morellato-Castillo, Laurence; Acharya, Priyamvada; Combes, Olivier; Michiels, Johan; Descours, Anne; Ramos, Oscar H. P.; Yang, Yongping; Vanham, Guido; Ariën, Kevin K.; Kwong, Peter D.; Martin, Loïc; Kessler, Pascal

    2013-01-01

    Ligand affinities can be optimized by interfacial cavity filling. A hollow (Phe43 cavity) between HIV-1 surface protein (gp120) and cluster of differentiation 4 (CD4) receptor, extends beyond residue phenylalanine 43 of CD4 and cannot be fully accessed by natural amino acids. To increase HIV-1 gp120 affinity for a family of CD4-mimetic miniproteins (miniCD4s), we targeted the gp120 Phe43 cavity with eleven non-natural phenylalanine derivatives, introduced into a miniCD4 named M48 (1). The best derivative named M48U12 (13) binds HIV-1 YU2 gp120 with 8 pM affinity, and shows potent HIV-1 neutralization. It contained a methylcyclohexyl derivative of 4-aminophenylalanine and its co-crystal structure with gp120 revealed the cyclohexane ring buried within the gp120 hydrophobic core but able to assume multiple orientations in the binding pocket, and an aniline nitrogen potentially providing a focus for further improvement. Altogether, the results provide a framework for filling the interfacial Phe43 cavity to enhance miniCD4 affinity. PMID:23710622

  19. HIV1-viral protein R (Vpr) mutations: associated phenotypes and relevance for clinical pathologies.

    PubMed

    Soares, Rui; Rocha, Graça; Meliço-Silvestre, António; Gonçalves, Teresa

    2016-09-01

    Over the last 30 years, research into HIV has advanced the knowledge of virus genetics and the development of efficient therapeutic strategies. HIV-1 viral protein R (Vpr) is a specialized and multifunctional protein that plays important roles at multiple stages of the HIV-1 viral life cycle. This protein interacts with a number of cellular and viral proteins and with multiple activities including nuclear transport of the pre-integration complex (PIC) to the nucleus, transcriptional activation, cell cycle arrest at G2/M transition phase and induction of cell death via apoptosis. Specifically, Vpr has been shown to control many host cell functions through a variety of biological processes and by interaction with several cellular pathways. The different functions of Vpr may enhance viral replication and impair the immune system in HIV-1 infected patients. Importantly, functional defects induced by mutations in the Vpr protein correlate with slow disease progression of HIV-infected patients. Vpr is also associated with other concomitant pathologies developed by these patients, which may lead it to be considered as a potential novel therapeutic target. This review will focus on HIV-1 Vpr, mainly on the importance of its structural mutations on the progression of HIV infection, associated phenotypes and relevance for clinical pathologies. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27264019

  20. Interfacial Cavity Filling To Optimize CD4-Mimetic Miniprotein Interactions with HIV-1 Surface Glycoprotein

    SciTech Connect

    Morellato-Castillo, Laurence; Acharya, Priyamvada; Combes, Olivier; Michiels, Johan; Descours, Anne; Ramos, Oscar H.P.; Yang, Yongping; Vanham, Guido; Ariën, Kevin K.; Kwong, Peter D.; Martin, Loïc; Kessler, Pascal

    2013-08-05

    Ligand affinities can be optimized by interfacial cavity filling. A hollow (Phe43 cavity) between HIV-1 surface glycoprotein (gp120) and cluster of differentiation 4 (CD4) receptor extends beyond residue phenylalanine 43 of CD4 and cannot be fully accessed by natural amino acids. To increase HIV-1 gp120 affinity for a family of CD4-mimetic miniproteins (miniCD4s), we targeted the gp120 Phe43 cavity with 11 non-natural phenylalanine derivatives, introduced into a miniCD4 named M48 (1). The best derivative, named M48U12 (13), bound HIV-1 YU2 gp120 with 8 pM affinity and showed potent HIV-1 neutralization. It contained a methylcyclohexyl derivative of 4-aminophenylalanine, and its cocrystal structure with gp120 revealed the cyclohexane ring buried within the gp120 hydrophobic core but able to assume multiple orientations in the binding pocket, and the aniline nitrogen potentially providing a focus for further improvement. Altogether, the results provide a framework for filling the interfacial Phe43 cavity to enhance miniCD4 affinity.

  1. The higher barrier of darunavir and tipranavir resistance for HIV-1 protease

    SciTech Connect

    Wang, Yong; Liu, Zhigang; Brunzelle, Joseph S.; Kovari, Iulia A.; Dewdney, Tamaria G.; Reiter, Samuel J.; Kovari, Ladislau C.

    2011-11-17

    Darunavir and tipranavir are two inhibitors that are active against multi-drug resistant (MDR) HIV-1 protease variants. In this study, the invitro inhibitory efficacy was tested against a MDR HIV-1 protease variant, MDR 769 82T, containing the drug resistance mutations of 46L/54V/82T/84V/90M. Crystallographic and enzymatic studies were performed to examine the mechanism of resistance and the relative maintenance of potency. The key findings are as follows: (i) The MDR protease exhibits decreased susceptibility to all nine HIV-1 protease inhibitors approved by the US Food and Drug Administration (FDA), among which darunavir and tipranavir are the most potent; (ii) the threonine 82 mutation on the protease greatly enhances drug resistance by altering the hydrophobicity of the binding pocket; (iii) darunavir or tipranavir binding facilitates closure of the wide-open flaps of the MDR protease; and (iv) the remaining potency of tipranavir may be preserved by stabilizing the flaps in the inhibitor-protease complex while darunavir maintains its potency by preserving protein main chain hydrogen bonds with the flexible P2 group. These results could provide new insights into drug design strategies to overcome multi-drug resistance of HIV-1 protease variants.

  2. A review of HIV-1 in Africa.

    PubMed

    Ronald, A R; Ndinya-Achola, J O; Plummer, F A; Simonsen, J N; Cameron, D W; Ngugi, E N; Pamba, H

    1988-01-01

    As the AIDS epidemic reaches a dramatic stage of development, the time for African countries to establish effective control programs has come. The history of AIDS in Africa is different from that other regions of the world. The disease developed among heterosexual communities. By 1987, over 8,000 cases of AIDS had been reported from 37 of the 47 nations of Africa. Over 2,000 of these cases were found in Uganda. However, under-reporting and under-representation of the number of actual cases is still a problem. In many cases, there has been a failure to recognize the disease. The demographic and geographic distribution of seroprevalence is discussed. Because of the inaccuracies in AIDS reporting in Africa, epidemic forecasting is difficult. If 5 million are currently infected, a potential 50 million Africans may be infected by 1993. A further discussion of the risk factors for HIV-1 holds that promiscuity is the major problem. Cures and inexpensive treatments for the infection are years away. Energy, resources, and national committees in Africa and the world must be coordinated to combat the ultimate crisis of this century.

  3. Anti-HIV-1 activity of flavonoid myricetin on HIV-1 infection in a dual-chamber in vitro model.

    PubMed

    Pasetto, Silvana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2014-01-01

    HIV infection by sexual transmission remains an enormous global health concern. More than 1 million new infections among women occur annually. Microbicides represent a promising prevention strategy that women can easily control. Among emerging therapies, natural small molecules such as flavonoids are an important source of new active substances. In this study we report the in vitro cytotoxicity and anti-HIV-1 and microbicide activity of the following flavonoids: Myricetin, Quercetin and Pinocembrin. Cytotoxicity tests were conducted on TZM-bl, HeLa, PBMC, and H9 cell cultures using 0.01-100 µM concentrations. Myricetin presented the lowest toxic effect, with Quercetin and Pinocembrin relatively more toxic. The anti-HIV-1 activity was tested with TZM-bl cell plus HIV-1 BaL (R5 tropic), H9 and PBMC cells plus HIV-1 MN (X4 tropic), and the dual tropic (X4R5) HIV-1 89.6. All flavonoids showed anti-HIV activity, although Myricetin was more effective than Quercetin or Pinocembrin. In TZM-bl cells, Myricetin inhibited ≥90% of HIV-1 BaL infection. The results were confirmed by quantification of HIV-1 p24 antigen in supernatant from H9 and PBMC cells following flavonoid treatment. In H9 and PBMC cells infected by HIV-1 MN and HIV-1 89.6, Myricetin showed more than 80% anti-HIV activity. Quercetin and Pinocembrin presented modest anti-HIV activity in all experiments. Myricetin activity was tested against HIV-RT and inhibited the enzyme by 49%. Microbicide activities were evaluated using a dual-chamber female genital tract model. In the in vitro microbicide activity model, Myricetin showed promising results against different strains of HIV-1 while also showing insignificant cytotoxic effects. Further studies of Myricetin should be performed to identify its molecular targets in order to provide a solid biological foundation for translational research.

  4. Anti-HIV-1 Activity of Flavonoid Myricetin on HIV-1 Infection in a Dual-Chamber In Vitro Model

    PubMed Central

    Pasetto, Silvana; Pardi, Vanessa; Murata, Ramiro Mendonça

    2014-01-01

    HIV infection by sexual transmission remains an enormous global health concern. More than 1 million new infections among women occur annually. Microbicides represent a promising prevention strategy that women can easily control. Among emerging therapies, natural small molecules such as flavonoids are an important source of new active substances. In this study we report the in vitro cytotoxicity and anti-HIV-1 and microbicide activity of the following flavonoids: Myricetin, Quercetin and Pinocembrin. Cytotoxicity tests were conducted on TZM-bl, HeLa, PBMC, and H9 cell cultures using 0.01–100 µM concentrations. Myricetin presented the lowest toxic effect, with Quercetin and Pinocembrin relatively more toxic. The anti-HIV-1 activity was tested with TZM-bl cell plus HIV-1 BaL (R5 tropic), H9 and PBMC cells plus HIV-1 MN (X4 tropic), and the dual tropic (X4R5) HIV-1 89.6. All flavonoids showed anti-HIV activity, although Myricetin was more effective than Quercetin or Pinocembrin. In TZM-bl cells, Myricetin inhibited ≥90% of HIV-1 BaL infection. The results were confirmed by quantification of HIV-1 p24 antigen in supernatant from H9 and PBMC cells following flavonoid treatment. In H9 and PBMC cells infected by HIV-1 MN and HIV-1 89.6, Myricetin showed more than 80% anti-HIV activity. Quercetin and Pinocembrin presented modest anti-HIV activity in all experiments. Myricetin activity was tested against HIV-RT and inhibited the enzyme by 49%. Microbicide activities were evaluated using a dual-chamber female genital tract model. In the in vitro microbicide activity model, Myricetin showed promising results against different strains of HIV-1 while also showing insignificant cytotoxic effects. Further studies of Myricetin should be performed to identify its molecular targets in order to provide a solid biological foundation for translational research. PMID:25546350

  5. Identification of Siglec-1 null individuals infected with HIV-1.

    PubMed

    Martinez-Picado, Javier; McLaren, Paul J; Erkizia, Itziar; Martin, Maureen P; Benet, Susana; Rotger, Margalida; Dalmau, Judith; Ouchi, Dan; Wolinsky, Steven M; Penugonda, Sudhir; Günthard, Huldrych F; Fellay, Jacques; Carrington, Mary; Izquierdo-Useros, Nuria; Telenti, Amalio

    2016-01-01

    Siglec-1/CD169 is a myeloid-cell surface receptor critical for HIV-1 capture and infection of bystander target cells. To dissect the role of SIGLEC1 in natura, we scan a large population genetic database and identify a loss-of-function variant (Glu88Ter) that is found in ∼1% of healthy people. Exome analysis and direct genotyping of 4,233 HIV-1-infected individuals reveals two Glu88Ter homozygous and 97 heterozygous subjects, allowing the analysis of ex vivo and in vivo consequences of SIGLEC1 loss-of-function. Cells from these individuals are functionally null or haploinsufficient for Siglec-1 activity in HIV-1 capture and trans-infection ex vivo. However, Siglec-1 protein truncation does not have a measurable impact on HIV-1 acquisition or AIDS outcomes in vivo. This result contrasts with the known in vitro functional role of Siglec-1 in HIV-1 trans-infection. Thus, it provides evidence that the classical HIV-1 infectious routes may compensate for the lack of Siglec-1 in fuelling HIV-1 dissemination within infected individuals. PMID:27510803

  6. Identification of Siglec-1 null individuals infected with HIV-1

    PubMed Central

    Martinez-Picado, Javier; McLaren, Paul J.; Erkizia, Itziar; Martin, Maureen P.; Benet, Susana; Rotger, Margalida; Dalmau, Judith; Ouchi, Dan; Wolinsky, Steven M.; Penugonda, Sudhir; Günthard, Huldrych F.; Fellay, Jacques; Carrington, Mary; Izquierdo-Useros, Nuria; Telenti, Amalio

    2016-01-01

    Siglec-1/CD169 is a myeloid-cell surface receptor critical for HIV-1 capture and infection of bystander target cells. To dissect the role of SIGLEC1 in natura, we scan a large population genetic database and identify a loss-of-function variant (Glu88Ter) that is found in ∼1% of healthy people. Exome analysis and direct genotyping of 4,233 HIV-1-infected individuals reveals two Glu88Ter homozygous and 97 heterozygous subjects, allowing the analysis of ex vivo and in vivo consequences of SIGLEC1 loss-of-function. Cells from these individuals are functionally null or haploinsufficient for Siglec-1 activity in HIV-1 capture and trans-infection ex vivo. However, Siglec-1 protein truncation does not have a measurable impact on HIV-1 acquisition or AIDS outcomes in vivo. This result contrasts with the known in vitro functional role of Siglec-1 in HIV-1 trans-infection. Thus, it provides evidence that the classical HIV-1 infectious routes may compensate for the lack of Siglec-1 in fuelling HIV-1 dissemination within infected individuals. PMID:27510803

  7. Defining the roles for Vpr in HIV-1-associated neuropathogenesis.

    PubMed

    James, Tony; Nonnemacher, Michael R; Wigdahl, Brian; Krebs, Fred C

    2016-08-01

    It is increasingly evident that the human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) has a unique role in neuropathogenesis. Its ability to induce G2/M arrest coupled with its capacity to increase viral gene transcription gives it a unique role in sustaining viral replication and aiding in the establishment and maintenance of a systemic infection. The requirement of Vpr for HIV-1 infection and replication in cells of monocytic origin (a key lineage of cells involved in HIV-1 neuroinvasion) suggests an important role in establishing and sustaining infection in the central nervous system (CNS). Contributions of Vpr to neuropathogenesis can be expanded further through (i) naturally occurring HIV-1 sequence variation that results in functionally divergent Vpr variants; (ii) the dual activities of Vpr as a intracellular protein delivered and expressed during HIV-1 infection and as an extracellular protein that can act on neighboring, uninfected cells; (iii) cell type-dependent consequences of Vpr expression and exposure, including cell cycle arrest, metabolic dysregulation, and cytotoxicity; and (iv) the effects of Vpr on exosome-based intercellular communication in the CNS. Revealing that the effects of this pleiotropic viral protein is an essential part of a greater understanding of HIV-1-associated pathogenesis and potential approaches to treating and preventing disease caused by HIV-1 infection.

  8. Defining the roles for Vpr in HIV-1-associated neuropathogenesis.

    PubMed

    James, Tony; Nonnemacher, Michael R; Wigdahl, Brian; Krebs, Fred C

    2016-08-01

    It is increasingly evident that the human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) has a unique role in neuropathogenesis. Its ability to induce G2/M arrest coupled with its capacity to increase viral gene transcription gives it a unique role in sustaining viral replication and aiding in the establishment and maintenance of a systemic infection. The requirement of Vpr for HIV-1 infection and replication in cells of monocytic origin (a key lineage of cells involved in HIV-1 neuroinvasion) suggests an important role in establishing and sustaining infection in the central nervous system (CNS). Contributions of Vpr to neuropathogenesis can be expanded further through (i) naturally occurring HIV-1 sequence variation that results in functionally divergent Vpr variants; (ii) the dual activities of Vpr as a intracellular protein delivered and expressed during HIV-1 infection and as an extracellular protein that can act on neighboring, uninfected cells; (iii) cell type-dependent consequences of Vpr expression and exposure, including cell cycle arrest, metabolic dysregulation, and cytotoxicity; and (iv) the effects of Vpr on exosome-based intercellular communication in the CNS. Revealing that the effects of this pleiotropic viral protein is an essential part of a greater understanding of HIV-1-associated pathogenesis and potential approaches to treating and preventing disease caused by HIV-1 infection. PMID:27056720

  9. Estimation of HIV-1 DNA Level Interfering with Reliability of HIV-1 RNA Quantification Performed on Dried Blood Spots Collected from Successfully Treated Patients.

    PubMed

    Zida, Sylvie; Tuaillon, Edouard; Barro, Makoura; Kwimatouo Lekpa Franchard, Arnaud; Kagoné, Thérèse; Nacro, Boubacar; Ouedraogo, Abdoul Salam; Bolloré, Karine; Sanosyan, Armen; Plantier, Jean-Christophe; Meda, Nicolas; Sangaré, Lassana; Rouzioux, Christine; Rouet, François; Kania, Dramane

    2016-06-01

    The impact of HIV-1 DNA coamplification during HIV-1 RNA quantification on dried blood spots (DBS) was explored. False-positive HIV RNA detection (22/62, 35%) was associated with high HIV-1 DNA levels. Specificity of HIV-1 RNA assays on DBS should be evaluated following manufacturer protocols on samples with HIV-1 DNA levels of ≥1,000 copies/10(6) peripheral blood mononuclear cells. PMID:27008874

  10. Early Combination Antiretroviral Therapy Limits Exposure to HIV-1 Replication and Cell-Associated HIV-1 DNA Levels in Infants

    PubMed Central

    McManus, Margaret; Mick, Eric; Hudson, Richard; Mofenson, Lynne M.; Sullivan, John L.; Somasundaran, Mohan; Luzuriaga, Katherine

    2016-01-01

    The primary aim of this study was to measure HIV-1 persistence following combination antiretroviral therapy (cART) in infants and children. Peripheral blood mononuclear cell (PBMC) HIV-1 DNA was quantified prior to and after 1 year of cART in 30 children, stratified by time of initiation (early, age <3 months, ET; late, age >3 months-2 years, LT). Pre-therapy PBMC HIV-1 DNA levels correlated with pre-therapy plasma HIV-1 levels (r = 0.59, p<0.001), remaining statistically significant (p = 0.002) after adjustment for prior perinatal antiretroviral exposure and age at cART initiation. PBMC HIV-1 DNA declined significantly after 1 year of cART (Overall: -0.91±0.08 log10 copies per million PBMC, p<0.001; ET: -1.04±0.11 log10 DNA copies per million PBMC, p<0.001; LT: -0.74 ±0.13 log10 DNA copies per million PBMC, p<0.001) but rates of decline did not differ significantly between ET and LT. HIV-1 replication exposure over the first 12 months of cART, estimated as area-under-the-curve (AUC) of circulating plasma HIV-1 RNA levels, was significantly associated with PBMC HIV-1 DNA at one year (r = 0.51, p = 0.004). In 21 children with sustained virologic suppression after 1 year of cART, PBMC HIV-1 DNA levels continued to decline between years 1 and 4 (slope -0.21 log10 DNA copies per million PBMC per year); decline slopes did not differ significantly between ET and LT. PBMC HIV-1 DNA levels at 1 year and 4 years of cART correlated with age at cART initiation (1 year: p = 0.04; 4 years: p = 0.03) and age at virologic control (1 and 4 years, p = 0.02). Altogether, these data indicate that reducing exposure to HIV-1 replication and younger age at cART initiation are associated with lower HIV-1 DNA levels at and after one year of age, supporting the concept that HIV-1 diagnosis and cART initiation in infants should occur as early as possible. PMID:27104621

  11. 6,7-Dihydroxy-1-oxoisoindoline-4-sulfonamide-containing HIV-1 integrase inhibitors.

    PubMed

    Zhao, Xue Zhi; Maddali, Kasthuraiah; Smith, Steven J; Métifiot, Mathieu; Johnson, Barry C; Marchand, Christophe; Hughes, Stephen H; Pommier, Yves; Burke, Terrence R

    2012-12-15

    Although an extensive body of scientific and patent literature exists describing the development of HIV-1 integrase (IN) inhibitors, Merck's raltegravir and Gilead's elvitegravir remain the only IN inhibitors FDA-approved for the treatment of AIDS. The emergence of raltegravir-resistant strains of HIV-1 containing mutated forms of IN underlies the need for continued efforts to enhance the efficacy of IN inhibitors against resistant mutants. We have previously described bicyclic 6,7-dihydroxyoxoisoindolin-1-ones that show good IN inhibitory potency. This report describes the effects of introducing substituents into the 4- and 5-positions of the parent 6,7-dihydroxyoxoisoindolin-1-one platform. We have developed several sulfonamide-containing analogs that enhance potency in cell-based HIV assays by more than two orders-of-magnitude and we describe several compounds that are more potent than raltegravir against the clinically relevant Y143R IN mutant.

  12. Assessment of Recent HIV-1 Infection by a Line Immunoassay for HIV-1/2 Confirmation

    PubMed Central

    Schüpbach, Jörg; Gebhardt, Martin D; Tomasik, Zuzana; Niederhauser, Christoph; Yerly, Sabine; Bürgisser, Philippe; Matter, Lukas; Gorgievski, Meri; Dubs, Rolf; Schultze, Detlev; Steffen, Ingrid; Andreutti, Corinne; Martinetti, Gladys; Güntert, Bruno; Staub, Roger; Daneel, Synove; Vernazza, Pietro

    2007-01-01

    Background Knowledge of the number of recent HIV infections is important for epidemiologic surveillance. Over the past decade approaches have been developed to estimate this number by testing HIV-seropositive specimens with assays that discriminate the lower concentration and avidity of HIV antibodies in early infection. We have investigated whether this “recency” information can also be gained from an HIV confirmatory assay. Methods and Findings The ability of a line immunoassay (INNO-LIA HIV I/II Score, Innogenetics) to distinguish recent from older HIV-1 infection was evaluated in comparison with the Calypte HIV-1 BED Incidence enzyme immunoassay (BED-EIA). Both tests were conducted prospectively in all HIV infections newly diagnosed in Switzerland from July 2005 to June 2006. Clinical and laboratory information indicative of recent or older infection was obtained from physicians at the time of HIV diagnosis and used as the reference standard. BED-EIA and various recency algorithms utilizing the antibody reaction to INNO-LIA's five HIV-1 antigen bands were evaluated by logistic regression analysis. A total of 765 HIV-1 infections, 748 (97.8%) with complete test results, were newly diagnosed during the study. A negative or indeterminate HIV antibody assay at diagnosis, symptoms of primary HIV infection, or a negative HIV test during the past 12 mo classified 195 infections (26.1%) as recent (≤ 12 mo). Symptoms of CDC stages B or C classified 161 infections as older (21.5%), and 392 patients with no symptoms remained unclassified. BED-EIA ruled 65% of the 195 recent infections as recent and 80% of the 161 older infections as older. Two INNO-LIA algorithms showed 50% and 40% sensitivity combined with 95% and 99% specificity, respectively. Estimation of recent infection in the entire study population, based on actual results of the three tests and adjusted for a test's sensitivity and specificity, yielded 37% for BED-EIA compared to 35% and 33% for the two

  13. Rapid detection of HIV-1 p24 antigen using magnetic immuno-chromatography (MICT).

    PubMed

    Workman, Shon; Wells, Susan K; Pau, Chou-Pong; Owen, S Michele; Dong, X Fan; LaBorde, Ron; Granade, Timothy C

    2009-09-01

    Detection of human immunodeficiency virus (HIV) infections has been enhanced by incorporating p24 antigen detection with current HIV antibody detection using enzyme immunoassays (EIAs). However, screening for HIV antibodies has increased through the use of rapid, lateral-flow HIV antibody detection assays that currently do not have the capability to detect HIV p24 antigen. In this report, a lateral-flow based assay using super-paramagnetic particles as the detection marker was developed for the detection of HIV-1 p24 antigen. This magnetic immuno-chromatographic test (MICT) uses an inexpensive, low-maintenance instrument that detects the magnetic moment of the super-paramagnetic particles in a magnetic field. MICT is simple to perform, provides a numerical output for easier determination of reactive results and can be completed in 40min. The lower limit of detection for HIV-1 p24 spiked into assay sample buffer and 50% plasma was 30pg/ml for both. Detection of HIV-1 p24 antigen at 50pg/ml was reproducible in both inter-run and intra-run assays with coefficients of variation of <13%. Furthermore, the MICT p24 assay was able to detect intact virus spiked into 50% plasma (lower detection limit of approximately 250,000 viral RNA copies/ml). MICT detection of increasing HIV-1 p24 levels in commercially available seroconversion panels by MICT was only slightly later than that detected by much more complex EIAs. MICT could provide a simple, low-cost, and portable method for rapid HIV-1 p24 detection in a variety of testing environments. PMID:19482361

  14. Synergistic reduction of HIV-1 infectivity by 5-azacytidine and inhibitors of ribonucleotide reductase.

    PubMed

    Rawson, Jonathan M O; Roth, Megan E; Xie, Jiashu; Daly, Michele B; Clouser, Christine L; Landman, Sean R; Reilly, Cavan S; Bonnac, Laurent; Kim, Baek; Patterson, Steven E; Mansky, Louis M

    2016-06-01

    Although many compounds have been approved for the treatment of human immunodeficiency type-1 (HIV-1) infection, additional anti-HIV-1 drugs (particularly those belonging to new drug classes) are still needed due to issues such as long-term drug-associated toxicities, transmission of drug-resistant variants, and development of multi-class resistance. Lethal mutagenesis represents an antiviral strategy that has not yet been clinically translated for HIV-1 and is based on the use of small molecules to induce excessive levels of deleterious mutations within the viral genome. Here, we show that 5-azacytidine (5-aza-C), a ribonucleoside analog that induces the lethal mutagenesis of HIV-1, and multiple inhibitors of the enzyme ribonucleotide reductase (RNR) interact in a synergistic fashion to more effectively reduce the infectivity of HIV-1. In these drug combinations, RNR inhibitors failed to significantly inhibit the conversion of 5-aza-C to 5-aza-2'-deoxycytidine, suggesting that 5-aza-C acts primarily as a deoxyribonucleoside even in the presence of RNR inhibitors. The mechanism of antiviral synergy was further investigated for the combination of 5-aza-C and one specific RNR inhibitor, resveratrol, as this combination improved the selectivity index of 5-aza-C to the greatest extent. Antiviral synergy was found to be primarily due to the reduced accumulation of reverse transcription products rather than the enhancement of viral mutagenesis. To our knowledge, these observations represent the first demonstration of antiretroviral synergy between a ribonucleoside analog and RNR inhibitors, and encourage the development of additional ribonucleoside analogs and RNR inhibitors with improved antiretroviral activity. PMID:27117260

  15. Ex vivo gene therapy for HIV-1 treatment

    PubMed Central

    Scherer, Lisa J.; Rossi, John J.

    2011-01-01

    Until recently, progress in ex vivo gene therapy (GT) for human immunodeficiency virus-1 (HIV-1) treatment has been incremental. Long-term HIV-1 remission in a patient who received a heterologous stem cell transplant for acquired immunodeficiency syndrome-related lymphoma from a CCR5−/– donor, even after discontinuation of conventional therapy, has energized the field. We review the status of current approaches as well as future directions in the areas of therapeutic targets, combinatorial strategies, vector design, introduction of therapeutics into stem cells and enrichment/expansion of gene-modified cells. Finally, we discuss recent advances towards clinical application of HIV-1 GT. PMID:21505069

  16. Current Perspectives on HIV-1 Antiretroviral Drug Resistance

    PubMed Central

    Iyidogan, Pinar; Anderson, Karen S.

    2014-01-01

    Current advancements in antiretroviral therapy (ART) have turned HIV-1 infection into a chronic and manageable disease. However, treatment is only effective until HIV-1 develops resistance against the administered drugs. The most recent antiretroviral drugs have become superior at delaying the evolution of acquired drug resistance. In this review, the viral fitness and its correlation to HIV-1 mutation rates and drug resistance are discussed while emphasizing the concept of lethal mutagenesis as an alternative therapy. The development of resistance to the different classes of approved drugs and the importance of monitoring antiretroviral drug resistance are also summarized briefly. PMID:25341668

  17. HIV-1 Replication and the Cellular Eukaryotic Translation Apparatus

    PubMed Central

    Guerrero, Santiago; Batisse, Julien; Libre, Camille; Bernacchi, Serena; Marquet, Roland; Paillart, Jean-Christophe

    2015-01-01

    Eukaryotic translation is a complex process composed of three main steps: initiation, elongation, and termination. During infections by RNA- and DNA-viruses, the eukaryotic translation machinery is used to assure optimal viral protein synthesis. Human immunodeficiency virus type I (HIV-1) uses several non-canonical pathways to translate its own proteins, such as leaky scanning, frameshifting, shunt, and cap-independent mechanisms. Moreover, HIV-1 modulates the host translation machinery by targeting key translation factors and overcomes different cellular obstacles that affect protein translation. In this review, we describe how HIV-1 proteins target several components of the eukaryotic translation machinery, which consequently improves viral translation and replication. PMID:25606970

  18. Gelsolin activity controls efficient early HIV-1 infection

    PubMed Central

    2013-01-01

    Background HIV-1 entry into target lymphocytes requires the activity of actin adaptors that stabilize and reorganize cortical F-actin, like moesin and filamin-A. These alterations are necessary for the redistribution of CD4-CXCR4/CCR5 to one pole of the cell, a process that increases the probability of HIV-1 Envelope (Env)-CD4/co-receptor interactions and that generates the tension at the plasma membrane necessary to potentiate fusion pore formation, thereby favouring early HIV-1 infection. However, it remains unclear whether the dynamic processing of F-actin and the amount of cortical actin available during the initial virus-cell contact are required to such events. Results Here we show that gelsolin restructures cortical F-actin during HIV-1 Env-gp120-mediated signalling, without affecting cell-surface expression of receptors or viral co-receptor signalling. Remarkably, efficient HIV-1 Env-mediated membrane fusion and infection of permissive lymphocytes were impaired when gelsolin was either overexpressed or silenced, which led to a loss or gain of cortical actin, respectively. Indeed, HIV-1 Env-gp120-induced F-actin reorganization and viral receptor capping were impaired under these experimental conditions. Moreover, gelsolin knockdown promoted HIV-1 Env-gp120-mediated aberrant pseudopodia formation. These perturbed-actin events are responsible for the inhibition of early HIV-1 infection. Conclusions For the first time we provide evidence that through its severing of cortical actin, and by controlling the amount of actin available for reorganization during HIV-1 Env-mediated viral fusion, entry and infection, gelsolin can constitute a barrier that restricts HIV-1 infection of CD4+ lymphocytes in a pre-fusion step. These findings provide important insights into the complex molecular and actin-associated dynamics events that underlie early viral infection. Thus, we propose that gelsolin is a new factor that can limit HIV-1 infection acting at a pre-fusion step

  19. Towards an HIV-1 cure: measuring the latent reservoir

    PubMed Central

    Bruner, Katherine M.; Hosmane, Nina N.; Siliciano, Robert F.

    2015-01-01

    The latent reservoir of HIV-1 in resting memory CD4+ T cells serves as a major barrier to curing HIV-1 infection. While many PCR- and culture-based assays have been used to measure the size of the latent reservoir, correlation between results of different assays is poor and recent studies indicate that no available assay provides an accurate measurement of reservoir size. The discrepancies between assays are a hurdle to clinical trials that aim to measure the efficacy of HIV-1 eradication strategies. Here we describe the advantages and disadvantages of various approaches to measure the latent reservoir. PMID:25747663

  20. MicroRNAs and HIV-1: Complex Interactions*

    PubMed Central

    Klase, Zachary; Houzet, Laurent; Jeang, Kuan-Teh

    2012-01-01

    RNAi plays important roles in many biological processes, including cellular defense against viral infection. Components of the RNAi machinery are widely conserved in plants and animals. In mammals, microRNAs (miRNAs) represent an abundant class of cell encoded small noncoding RNAs that participate in RNAi-mediated gene silencing. Here, findings that HIV-1 replication in cells can be regulated by miRNAs and that HIV-1 infection of cells can alter cellular miRNA expression are reviewed. Lessons learned from and questions outstanding about the complex interactions between HIV-1 and cellular miRNAs are discussed. PMID:23043098

  1. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells.

    PubMed

    Mouser, Emily E I M; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William; de Jong, Esther C; Paxton, William A

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  2. Brugia malayi Antigen (BmA) Inhibits HIV-1 Trans-Infection but Neither BmA nor ES-62 Alter HIV-1 Infectivity of DC Induced CD4+ Th-Cells

    PubMed Central

    Mouser, Emily E. I. M.; Pollakis, Georgios; Yazdanbakhsh, Maria; Harnett, William

    2016-01-01

    One of the hallmarks of HIV-1 disease is the association of heightened CD4+ T-cell activation with HIV-1 replication. Parasitic helminths including filarial nematodes have evolved numerous and complex mechanisms to skew, dampen and evade human immune responses suggesting that HIV-1 infection may be modulated in co-infected individuals. Here we studied the effects of two filarial nematode products, adult worm antigen from Brugia malayi (BmA) and excretory-secretory product 62 (ES-62) from Acanthocheilonema viteae on HIV-1 infection in vitro. Neither BmA nor ES-62 influenced HIV-1 replication in CD4+ enriched T-cells, with either a CCR5- or CXCR4-using virus. BmA, but not ES-62, had the capacity to bind the C-type lectin dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN) thereby inhibiting HIV-1 trans-infection of CD4+ enriched T-cells. As for their effect on DCs, neither BmA nor ES-62 could enhance or inhibit DC maturation as determined by CD83, CD86 and HLA-DR expression, or the production of IL-6, IL-10, IL-12 and TNF-α. As expected, due to the unaltered DC phenotype, no differences were found in CD4+ T helper (Th) cell phenotypes induced by DCs treated with either BmA or ES-62. Moreover, the HIV-1 susceptibility of the Th-cell populations induced by BmA or ES-62 exposed DCs was unaffected for both CCR5- and CXCR4-using HIV-1 viruses. In conclusion, although BmA has the potential capacity to interfere with HIV-1 transmission or initial viral dissemination through preventing the virus from interacting with DCs, no differences in the Th-cell polarizing capacity of DCs exposed to BmA or ES-62 were observed. Neither antigenic source demonstrated beneficial or detrimental effects on the HIV-1 susceptibility of CD4+ Th-cells induced by exposed DCs. PMID:26808476

  3. Comparison of the Cepheid GeneXpert and Abbott M2000 HIV-1 real time molecular assays for monitoring HIV-1 viral load and detecting HIV-1 infection.

    PubMed

    Ceffa, Susanna; Luhanga, Richard; Andreotti, Mauro; Brambilla, Davide; Erba, Fulvio; Jere, Haswel; Mancinelli, Sandro; Giuliano, Marina; Palombi, Leonardo; Marazzi, Maria Cristina

    2016-03-01

    Assessing treatment efficacy and early infant diagnosis (EID) are critical issues in HIV disease management. Point-of-care assays may greatly increase the possibility to access laboratory monitoring also in rural areas. Recently two new laboratory tests have been developed by Cepheid (Sunnyvale, California) the Xpert HIV-1 Viral Load for viral load determination and the Xpert HIV-1 Qualitative for early infant diagnosis. We conducted a study in Blantyre, Malawi, comparing the 2 methods versus the Abbott real time quantitative and qualitative assays, for viral load and EID respectively. We tested 300 plasma samples for viral load determination and 200 samples for infant diagnosis. HIV-1 RNA values of the 274 samples quantified by both assays were highly correlated (Pearson r=0.95, R(2)=0.90). In 90.9% of the cases the two methods were concordant in defining the HIV-1 RNA levels as detectable or undetectable. For EID, the Xpert HIV-1 Qualitative assay yielded the same identical results as the Abbott assay. Both the quantitative and the qualitative Xpert assays are promising tools to monitor treatment efficacy in HIV patients receiving treatment and for early diagnosis in HIV-exposed infants. PMID:26709099

  4. Comparison of a conventional HIV 1/2 line immunoassay with a rapid confirmatory HIV 1/2 assay.

    PubMed

    Tinguely, Caroline; Schild-Spycher, Therese; Bahador, Zahra; Gowland, Peter; Stolz, Martin; Niederhauser, Christoph

    2014-09-01

    The performance of the rapid confirmatory HIV 1/2 assay Geenius was compared with the conventional HIV 1/2 line immunoblot (INNO-LIA HIV I/II Score). One hundred HIV 1/2 confirmed positive samples from donors and patients and 136 negative screening samples from blood donors were evaluated with both assays. A 20 member performance panel consisting of different HIV 1 and 2 subtypes was also analysed. Ninety-nine of the confirmed HIV positive samples were positive with both assays. One sample was positive with the INNO-LIA HIV I/II Score but indeterminate with the Geenius HIV 1/2. From 136 negative blood donor samples (negative with a combo HIV assay and a highly sensitive ID-NAT), 125 were concordant negative. Six and five samples were incorrectly indeterminate with the INNO-LIA HIV I/II Score and the Geenius HIV 1/2, respectively. One sample was weak positive with the INNO-LIA HIV I/II Score but negative with the Geenius HIV 1/2. The 20 member performance showed equivalent results with both assays. The rapid assay showed a comparable sensitivity and specificity for confirmation for positive and negative HIV donor and patient samples as well for a 20 member performance panel.

  5. [Importance of amastigote forms morphology to differentiate Leishmania infantum and Leishmania major species].

    PubMed

    Aoun, K; Chahed, M K; Mokni, M; Harrat, Z; Bouratbine, A

    2003-01-01

    The microscopic study of the dermal smears of 62 cases of cutaneous leishmaniose, 27 infected by Leishmania (L.) infantum and 35 by L. major, showed that the amastigotes of L. infantum are meaningfully smaller (p < 0.001). This criteria is a simple pary alternative to distinguish these 2 species which have completely different epidemiology, recovery delay and prophylactic dispositions.

  6. Leishmania mexicana metacaspase is a negative regulator of amastigote proliferation in mammalian cells

    PubMed Central

    Castanys-Muñoz, E; Brown, E; Coombs, G H; Mottram, J C

    2012-01-01

    Metacaspases (MCAs) are caspase family cysteine peptidases that have been implicated in cell death processes in plants, fungi and protozoa. MCAs have also been suggested to be involved in cell cycle control, differentiation and clearance of aggregates; they are virulence factors. Dissecting the function of MCAs has been complicated by the presence in many organisms of multiple MCA genes or limitations on genetic manipulation. We describe here the creation of a MCA gene-deletion mutant (Δmca) in the protozoan parasite Leishmania mexicana, which has allowed us to dissect the role of the parasite's single MCA gene in cell growth and cell death. Δmca parasites are viable as promastigotes, and differentiate normally to the amastigote form both in in vitro macrophages infection and in mice. Δmca promastigotes respond to cell death inducers such as the drug miltefosine and H2O2 similarly to wild-type (WT) promastigotes, suggesting that MCAs do not have a caspase-like role in execution of L. mexicana cell death. Δmca amastigotes replicated significantly faster than WT amastigotes in macrophages and in mice, but not as axenic culture in vitro. We propose that the Leishmania MCA acts as a negative regulator of amastigote proliferation, thereby acting to balance cell growth and cell death. PMID:22951982

  7. Recent developments in the search for a cure for HIV-1 infection: targeting the latent reservoir for HIV-1.

    PubMed

    Siliciano, Janet D; Siliciano, Robert F

    2014-07-01

    HIV-1 infection can now be readily controlled with combination antiretroviral therapy. However, the virus persists indefinitely in a stable latent reservoir in resting CD4(+) T cells. This reservoir generally prevents cure of the infection with combination antiretroviral therapy alone. However, several recent cases of potential HIV-1 cure have generated renewed optimism. Here we review these cases and consider new developments in our understanding of the latent reservoir. In addition, we consider clinical aspects of curative strategies to provide a more realistic picture of what a generally applicable cure for HIV-1 infection is likely to entail.

  8. Enrichment of intersubtype HIV-1 recombinants in a dual infection system using HIV-1 strain-specific siRNAs

    PubMed Central

    2011-01-01

    Background Intersubtype HIV-1 recombinants in the form of unique or stable circulating recombinants forms (CRFs) are responsible for over 20% of infections in the worldwide epidemic. Mechanisms controlling the generation, selection, and transmission of these intersubtype HIV-1 recombinants still require further investigation. All intersubtype HIV-1 recombinants are generated and evolve from initial dual infections, but are difficult to identify in the human population. In vitro studies provide the most practical system to study mechanisms, but the recombination rates are usually very low in dual infections with primary HIV-1 isolates. This study describes the use of HIV-1 isolate-specific siRNAs to enrich intersubtype HIV-1 recombinants and inhibit the parental HIV-1 isolates from a dual infection. Results Following a dual infection with subtype A and D primary HIV-1 isolates and two rounds of siRNA treatment, nearly 100% of replicative virus was resistant to a siRNA specific for an upstream target sequence in the subtype A envelope (env) gene as well as a siRNA specific for a downstream target sequence in the subtype D env gene. Only 20% (10/50) of the replicating virus had nucleotide substitutions in the siRNA-target sequence whereas the remaining 78% (39/50) harbored a recombination breakpoint that removed both siRNA target sequences, and rendered the intersubtype D/A recombinant virus resistant to the dual siRNA treatment. Since siRNAs target the newly transcribed HIV-1 mRNA, the siRNAs only enrich intersubtype env recombinants and do not influence the recombination process during reverse transcription. Using this system, a strong bias is selected for recombination breakpoints in the C2 region, whereas other HIV-1 env regions, most notably the hypervariable regions, were nearly devoid of intersubtype recombination breakpoints. Sequence conservation plays an important role in selecting for recombination breakpoints, but the lack of breakpoints in many conserved

  9. High recombination potential of subtype A HIV-1.

    PubMed

    Nikolaitchik, Olga; Keele, Brandon; Gorelick, Robert; Alvord, W Gregory; Mazurov, Dmitriy; Pathak, Vinay K; Hu, Wei-Shau

    2015-10-01

    Recombination can assort polymorphic alleles to increase diversity in the HIV-1 population. To better understand the recombination potential of subtype A HIV-1, we generated viruses containing sequences from two variants circulating in Russia and analyzed the polymerase gene (pol) of the recombinants after one round of HIV-1 replication using single-genome sequencing. We observed that recombination occurred throughout pol and could easily assort alleles containing mutations that conferred resistance to currently approved antivirals. We measured the recombination rate in various regions of pol including a G-rich region that has been previously proposed to be a recombination hot spot. Our study does not support a recombination hot spot in this G-rich region. Importantly, of the 58 proviral sequences containing crossover event(s) in pol, we found that each sequence was a unique genotype indicating that recombination is a powerful genetic mechanism in assorting the genomes of subtype A HIV-1 variants.

  10. Evaluation of the Aptima(®) HIV-1 Quant Dx assay for HIV-1 RNA viral load detection and quantitation in plasma of HIV-1-infected individuals: A comparison with Abbott RealTime HIV-1 assay.

    PubMed

    Amendola, Alessandra; Pisciotta, Maria; Aleo, Loredana; Ferraioli, Valeria; Angeletti, Claudio; Capobianchi, Maria Rosaria

    2016-09-01

    The Hologic Aptima(®) HIV-1 Quant Dx assay (Aptima HIV) is a real-time transcription-mediated amplification method CE-approved for use in diagnosis and monitoring of HIV-1 infection. The analytical performance of this new assay was compared to the FDA-approved Abbott RealTime HIV-1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV-1 International Standard, and the QCMD HIV-1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV-1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV-1 Subtypes. With clinical samples, inter-assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 (P < 0.0001) and mean differences of measurement, conducted according to Bland-Altman method, was low (0.115 log10  copies/ml). The Aptima HIV quantified the WHO 3rd HIV-1 International Standard diluted from 2000 to 31 cp/ml (5,700-88 IU/ml) at expected values with excellent linearity (R(2)  > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV-1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV-1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV-1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535-1544, 2016. © 2016 Wiley Periodicals, Inc.

  11. Evaluation of the Aptima(®) HIV-1 Quant Dx assay for HIV-1 RNA viral load detection and quantitation in plasma of HIV-1-infected individuals: A comparison with Abbott RealTime HIV-1 assay.

    PubMed

    Amendola, Alessandra; Pisciotta, Maria; Aleo, Loredana; Ferraioli, Valeria; Angeletti, Claudio; Capobianchi, Maria Rosaria

    2016-09-01

    The Hologic Aptima(®) HIV-1 Quant Dx assay (Aptima HIV) is a real-time transcription-mediated amplification method CE-approved for use in diagnosis and monitoring of HIV-1 infection. The analytical performance of this new assay was compared to the FDA-approved Abbott RealTime HIV-1 (RealTime). The evaluation was performed using 220 clinical plasma samples, the WHO 3rd HIV-1 International Standard, and the QCMD HIV-1 RNA EQA. Concordance on qualitative results, correlation between quantitative results, accuracy, and reproducibility of viral load data were analyzed. The ability to measure HIV-1 subtypes was assessed on the second WHO International Reference Preparation Panel for HIV-1 Subtypes. With clinical samples, inter-assay agreement for qualitative results was high (91.8%) with Cohen's kappa statistic equal to 0.836. For samples with quantitative results in both assays (n = 93), Lin's concordance correlation coefficient was 0.980 (P < 0.0001) and mean differences of measurement, conducted according to Bland-Altman method, was low (0.115 log10  copies/ml). The Aptima HIV quantified the WHO 3rd HIV-1 International Standard diluted from 2000 to 31 cp/ml (5,700-88 IU/ml) at expected values with excellent linearity (R(2)  > 0.970) and showed higher sensitivity compared to RealTime being able to detect HIV-1 RNA in 10 out of 10 replicates containing down to 7 cp/ml (20 IU/ml). Reproducibility was very high, even at low HIV-1 RNA values. The Aptima HIV was able to detect and accurately quantify all the main HIV-1 subtypes in both reference panels and clinical samples. Besides excellent performance, Aptima HIV shows full automation, ease of use, and improved workflow compared to RealTime. J. Med. Virol. 88:1535-1544, 2016. © 2016 Wiley Periodicals, Inc. PMID:26864171

  12. HLA-C Downmodulation by HIV-1 Vpu.

    PubMed

    Barker, Edward; Evans, David T

    2016-05-11

    It is widely held that HIV-1 Nef downmodulates HLA-A and -B to protect infected cells from CD8(+) T cells but leaves HLA-C on the cell surface to inhibit NK cells. In this issue of Cell Host & Microbe, Apps et al. (2016) revise this model by showing that the Vpu protein of primary HIV-1 isolates downmodulate HLA-C.

  13. High HIV-1 Genetic Diversity in Patients from Northern Brazil.

    PubMed

    da Costa, Carolina Marinho; Costa de Oliveira, Cintia Mara; Chehuan de Melo, Yonne Francis; Delatorre, Edson; Bello, Gonzalo; Couto-Fernandez, Jose Carlos

    2016-09-01

    The HIV-1 epidemic in Brazil is driven by subtypes B, F1, and C and recombinants forms among those subtypes. The distribution of HIV-1 subtypes, however, may vary across different Brazilian regions and the molecular epidemiologic profile in Northern Brazil remains poorly explored. HIV-1 pol sequences were obtained from 305 patients failing antiretroviral therapy followed at outpatient clinics from five Northern Brazilian states. The most prevalent HIV-1 clade observed in the Northern Brazilian region was subtype B (81%), followed by BF1 recombinants (10%), subtype F1 (4%), subtype C (3%), BC recombinants (2%), and BU recombinants (1%). Although HIV-1 subtype B was the predominant HIV-1 clade in Northern Brazil, its prevalence greatly varies among different states, ranging from 63% in Rondônia to 92% in Acre. Among the 37 HIV-1 recombinant sequences detected in the Northern Brazilian region, nine (24%) displayed a unique recombinant form structure, five (14%) a CRF28/29_BF-like structure, and four (11%) a CRF31_BC-like structure. Two other BF1 recombinant patterns were identified in 16 (43%) and three (8%) samples that may correspond to two potentially new CRFs_BF characteristic of the Northern region. This study reveals that despite the low spatial connectivity with other Brazilian regions, the genetic complexity of the HIV-1 epidemic in Northern Brazil is very high and that the molecular epidemiologic pattern may vary across different northern states, reflecting a complex epidemic with multiple independent viral introductions into this Brazilian region. PMID:27091699

  14. High HIV-1 Genetic Diversity in Patients from Northern Brazil.

    PubMed

    da Costa, Carolina Marinho; Costa de Oliveira, Cintia Mara; Chehuan de Melo, Yonne Francis; Delatorre, Edson; Bello, Gonzalo; Couto-Fernandez, Jose Carlos

    2016-09-01

    The HIV-1 epidemic in Brazil is driven by subtypes B, F1, and C and recombinants forms among those subtypes. The distribution of HIV-1 subtypes, however, may vary across different Brazilian regions and the molecular epidemiologic profile in Northern Brazil remains poorly explored. HIV-1 pol sequences were obtained from 305 patients failing antiretroviral therapy followed at outpatient clinics from five Northern Brazilian states. The most prevalent HIV-1 clade observed in the Northern Brazilian region was subtype B (81%), followed by BF1 recombinants (10%), subtype F1 (4%), subtype C (3%), BC recombinants (2%), and BU recombinants (1%). Although HIV-1 subtype B was the predominant HIV-1 clade in Northern Brazil, its prevalence greatly varies among different states, ranging from 63% in Rondônia to 92% in Acre. Among the 37 HIV-1 recombinant sequences detected in the Northern Brazilian region, nine (24%) displayed a unique recombinant form structure, five (14%) a CRF28/29_BF-like structure, and four (11%) a CRF31_BC-like structure. Two other BF1 recombinant patterns were identified in 16 (43%) and three (8%) samples that may correspond to two potentially new CRFs_BF characteristic of the Northern region. This study reveals that despite the low spatial connectivity with other Brazilian regions, the genetic complexity of the HIV-1 epidemic in Northern Brazil is very high and that the molecular epidemiologic pattern may vary across different northern states, reflecting a complex epidemic with multiple independent viral introductions into this Brazilian region.

  15. Engineering T Cells to Functionally Cure HIV-1 Infection.

    PubMed

    Leibman, Rachel S; Riley, James L

    2015-07-01

    Despite the ability of antiretroviral therapy to minimize human immunodeficiency virus type 1 (HIV-1) replication and increase the duration and quality of patients' lives, the health consequences and financial burden associated with the lifelong treatment regimen render a permanent cure highly attractive. Although T cells play an important role in controlling virus replication, they are themselves targets of HIV-mediated destruction. Direct genetic manipulation of T cells for adoptive cellular therapies could facilitate a functional cure by generating HIV-1-resistant cells, redirecting HIV-1-specific immune responses, or a combination of the two strategies. In contrast to a vaccine approach, which relies on the production and priming of HIV-1-specific lymphocytes within a patient's own body, adoptive T-cell therapy provides an opportunity to customize the therapeutic T cells prior to administration. However, at present, it is unclear how to best engineer T cells so that sustained control over HIV-1 replication can be achieved in the absence of antiretrovirals. This review focuses on T-cell gene-engineering and gene-editing strategies that have been performed in efforts to inhibit HIV-1 replication and highlights the requirements for a successful gene therapy-mediated functional cure.

  16. Potent inhibition of HIV-1 replication by a Tat mutant.

    PubMed

    Meredith, Luke W; Sivakumaran, Haran; Major, Lee; Suhrbier, Andreas; Harrich, David

    2009-11-10

    Herein we describe a mutant of the two-exon HIV-1 Tat protein, termed Nullbasic, that potently inhibits multiple steps of the HIV-1 replication cycle. Nullbasic was created by replacing the entire arginine-rich basic domain of wild type Tat with glycine/alanine residues. Like similarly mutated one-exon Tat mutants, Nullbasic exhibited transdominant negative effects on Tat-dependent transactivation. However, unlike previously reported mutants, we discovered that Nullbasic also strongly suppressed the expression of unspliced and singly-spliced viral mRNA, an activity likely caused by redistribution and thus functional inhibition of HIV-1 Rev. Furthermore, HIV-1 virion particles produced by cells expressing Nullbasic had severely reduced infectivity, a defect attributable to a reduced ability of the virions to undergo reverse transcription. Combination of these inhibitory effects on transactivation, Rev-dependent mRNA transport and reverse transcription meant that permissive cells constitutively expressing Nullbasic were highly resistant to a spreading infection by HIV-1. Nullbasic and its activities thus provide potential insights into the development of potent antiviral therapeutics that target multiple stages of HIV-1 infection.

  17. Quantitative Phosphoproteomics Reveals Extensive Cellular Reprogramming During HIV-1 Entry

    PubMed Central

    Wojcechowskyj, Jason A.; Didigu, Chuka A.; Lee, Jessica Y.; Parrish, Nicholas F.; Sinha, Rohini; Hahn, Beatrice H.; Bushman, Frederic D.; Jensen, Shane T.; Seeholzer, Steven H.; Doms, Robert W.

    2014-01-01

    SUMMARY Receptor engagement by HIV-1 during host cell entry activates signaling pathways that can reprogram the cell for optimal viral replication. To obtain a global view of the signaling events induced during HIV-1 entry, we conducted a quantitative phosphoproteomics screen of primary human CD4+ T cell after infection with an HIV-1 strain that engages the receptors CD4 and CXCR4. We quantified 1,757 phosphorylation sites with high stringency. The abundance of 239 phosphorylation sites from 175 genes, including several proteins in pathways known to be impacted by HIV-receptor binding, changed significantly within a minute after HIV-1 exposure. Several previously uncharacterized HIV-1 host factors were also identified and confirmed through RNAi depletion studies. Surprisingly, 5 serine/arginine-rich (SR)-proteins involved in mRNA splicing, including the splicing factor SRm300 (SRRM2) were differentially phosophorylated. Mechanistic studies with SRRM2 suggest that HIV-1 modulates host cell alternative splicing machinery during entry in order to facilitate virus replication and release. PMID:23684312

  18. Identification of potent maturation inhibitors against HIV-1 clade C

    PubMed Central

    Timilsina, Uddhav; Ghimire, Dibya; Timalsina, Bivek; Nitz, Theodore J.; Wild, Carl T.; Freed, Eric O.; Gaur, Ritu

    2016-01-01

    Antiretroviral therapy has led to a profound improvement in the clinical care of HIV-infected patients. However, drug tolerability and the evolution of drug resistance have limited treatment options for many patients. Maturation inhibitors are a new class of antiretroviral agents for treatment of HIV-1. They act by interfering with the maturation of the virus by blocking the last step in Gag processing: the cleavage of the capsid-spacer peptide 1 (CA-SP1) intermediate to mature CA by the viral protease (PR). The first-in-class maturation inhibitor bevirimat (BVM) failed against a subset of HIV-1 isolates in clinical trials due to polymorphisms present in the CA-SP1 region of the Gag protein. Sequence analysis indicated that these polymorphisms are more common in non-clade B strains of HIV-1 such as HIV-1 clade C. Indeed, BVM was found to be ineffective against HIV-1 clade C molecular clones tested in this study. A number of BVM analogs were synthesized by chemical modifications at the C-28 position to improve its activity. The new BVM analogs displayed potent activity against HIV-1 clade B and C and also reduced infectivity of the virus. This study identifies novel and broadly active BVM analogs that may ultimately demonstrate efficacy in the clinic. PMID:27264714

  19. Engineering T Cells to Functionally Cure HIV-1 Infection

    PubMed Central

    Leibman, Rachel S; Riley, James L

    2015-01-01

    Despite the ability of antiretroviral therapy to minimize human immunodeficiency virus type 1 (HIV-1) replication and increase the duration and quality of patients' lives, the health consequences and financial burden associated with the lifelong treatment regimen render a permanent cure highly attractive. Although T cells play an important role in controlling virus replication, they are themselves targets of HIV-mediated destruction. Direct genetic manipulation of T cells for adoptive cellular therapies could facilitate a functional cure by generating HIV-1–resistant cells, redirecting HIV-1–specific immune responses, or a combination of the two strategies. In contrast to a vaccine approach, which relies on the production and priming of HIV-1–specific lymphocytes within a patient's own body, adoptive T-cell therapy provides an opportunity to customize the therapeutic T cells prior to administration. However, at present, it is unclear how to best engineer T cells so that sustained control over HIV-1 replication can be achieved in the absence of antiretrovirals. This review focuses on T-cell gene-engineering and gene-editing strategies that have been performed in efforts to inhibit HIV-1 replication and highlights the requirements for a successful gene therapy–mediated functional cure. PMID:25896251

  20. Negative Feedback Regulation of HIV-1 by Gene Editing Strategy.

    PubMed

    Kaminski, Rafal; Chen, Yilan; Salkind, Julian; Bella, Ramona; Young, Won-Bin; Ferrante, Pasquale; Karn, Jonathan; Malcolm, Thomas; Hu, Wenhui; Khalili, Kamel

    2016-01-01

    The CRISPR/Cas9 gene editing method is comprised of the guide RNA (gRNA) to target a specific DNA sequence for cleavage and the Cas9 endonuclease for introducing breaks in the double-stranded DNA identified by the gRNA. Co-expression of both a multiplex of HIV-1-specific gRNAs and Cas9 in cells results in the modification and/or excision of the segment of viral DNA, leading to replication-defective virus. In this study, we have personalized the activity of CRISPR/Cas9 by placing the gene encoding Cas9 under the control of a minimal promoter of HIV-1 that is activated by the HIV-1 Tat protein. We demonstrate that functional activation of CRISPR/Cas9 by Tat during the course of viral infection excises the designated segment of the integrated viral DNA and consequently suppresses viral expression. This strategy was also used in a latently infected CD4+ T-cell model after treatment with a variety of HIV-1 stimulating agents including PMA and TSA. Controlled expression of Cas9 by Tat offers a new strategy for safe implementation of the Cas9 technology for ablation of HIV-1 at a very early stage of HIV-1 replication during the course of the acute phase of infection and the reactivation of silent proviral DNA in latently infected cells. PMID:27528385

  1. Negative Feedback Regulation of HIV-1 by Gene Editing Strategy

    PubMed Central

    Kaminski, Rafal; Chen, Yilan; Salkind, Julian; Bella, Ramona; Young, Won-bin; Ferrante, Pasquale; Karn, Jonathan; Malcolm, Thomas; Hu, Wenhui; Khalili, Kamel

    2016-01-01

    The CRISPR/Cas9 gene editing method is comprised of the guide RNA (gRNA) to target a specific DNA sequence for cleavage and the Cas9 endonuclease for introducing breaks in the double-stranded DNA identified by the gRNA. Co-expression of both a multiplex of HIV-1-specific gRNAs and Cas9 in cells results in the modification and/or excision of the segment of viral DNA, leading to replication-defective virus. In this study, we have personalized the activity of CRISPR/Cas9 by placing the gene encoding Cas9 under the control of a minimal promoter of HIV-1 that is activated by the HIV-1 Tat protein. We demonstrate that functional activation of CRISPR/Cas9 by Tat during the course of viral infection excises the designated segment of the integrated viral DNA and consequently suppresses viral expression. This strategy was also used in a latently infected CD4+ T-cell model after treatment with a variety of HIV-1 stimulating agents including PMA and TSA. Controlled expression of Cas9 by Tat offers a new strategy for safe implementation of the Cas9 technology for ablation of HIV-1 at a very early stage of HIV-1 replication during the course of the acute phase of infection and the reactivation of silent proviral DNA in latently infected cells. PMID:27528385

  2. Myelopathy in a previously asymptomatic HIV-1-infected patient.

    PubMed

    Eyer-Silva, W A; Auto, I; Pinto, J F; Morais-de-Sá, C A

    2001-01-01

    A wide variety of disorders of diverse pathogenic mechanisms can trigger spinal cord dysfunction in HIV-1-infected patients. The most common such condition is HIV-1-associated myelopathy (HM) which characteristically complicates advanced HIV-1 disease in patients with low CD4 cell counts and previous AIDS-defining diagnoses. We describe an unusual presentation of HM in a previously asymptomatic patient with a relatively preserved CD4 cell count (458 cells/mm3) who was even unaware of his serological status. The patient presented with a clinically severe, slowly progressive myelopathy and could not walk unassisted. Significant neurological improvement could be obtained as rapidly as within 4 weeks after the institution of an antiretroviral combination of only two nucleoside analog HIV-1 reverse transcriptase inhibitors (zidovudine and didanosine). An HIV-1 protease inhibitor was also prescribed at that point but could only be added to intensify the regimen 3 months later, when significant neurological improvement had already been recorded. We also review the disorders reported to derange spinal cord function in previously asymptomatic HIV-1-infected patients.

  3. Structural basis of HIV-1 resistance to AZT by excision.

    PubMed

    Tu, Xiongying; Das, Kalyan; Han, Qianwei; Bauman, Joseph D; Clark, Arthur D; Hou, Xiaorong; Frenkel, Yulia V; Gaffney, Barbara L; Jones, Roger A; Boyer, Paul L; Hughes, Stephen H; Sarafianos, Stefan G; Arnold, Eddy

    2010-10-01

    Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

  4. Structural basis of HIV-1 resistance to AZT by excision

    SciTech Connect

    Tu, Xiongying; Das, Kalyan; Han, Qianwei; Bauman, Joseph D.; Clark, Jr., Arthur D.; Hou, Xiaorong; Frenkel, Yulia V.; Gaffney, Barbara L.; Jones, Roger A.; Boyer, Paul L.; Hughes, Stephen H.; Sarafianos, Stefan G.; Arnold, Eddy

    2011-11-23

    Human immunodeficiency virus (HIV-1) develops resistance to 3'-azido-2',3'-deoxythymidine (AZT, zidovudine) by acquiring mutations in reverse transcriptase that enhance the ATP-mediated excision of AZT monophosphate from the 3' end of the primer. The excision reaction occurs at the dNTP-binding site, uses ATP as a pyrophosphate donor, unblocks the primer terminus and allows reverse transcriptase to continue viral DNA synthesis. The excision product is AZT adenosine dinucleoside tetraphosphate (AZTppppA). We determined five crystal structures: wild-type reverse transcriptase-double-stranded DNA (RT-dsDNA)-AZTppppA; AZT-resistant (AZTr; M41L D67N K70R T215Y K219Q) RT-dsDNA-AZTppppA; AZTr RT-dsDNA terminated with AZT at dNTP- and primer-binding sites; and AZTr apo reverse transcriptase. The AMP part of AZTppppA bound differently to wild-type and AZTr reverse transcriptases, whereas the AZT triphosphate part bound the two enzymes similarly. Thus, the resistance mutations create a high-affinity ATP-binding site. The structure of the site provides an opportunity to design inhibitors of AZT-monophosphate excision.

  5. Inhibiting early-stage events in HIV-1 replication by small-molecule targeting of the HIV-1 capsid.

    PubMed

    Kortagere, Sandhya; Madani, Navid; Mankowski, Marie K; Schön, Arne; Zentner, Isaac; Swaminathan, Gokul; Princiotto, Amy; Anthony, Kevin; Oza, Apara; Sierra, Luz-Jeannette; Passic, Shendra R; Wang, Xiaozhao; Jones, David M; Stavale, Eric; Krebs, Fred C; Martín-García, Julio; Freire, Ernesto; Ptak, Roger G; Sodroski, Joseph; Cocklin, Simon; Smith, Amos B

    2012-08-01

    The HIV-1 capsid (CA) protein plays essential roles in both early and late stages of virl replication and has emerged as a novel drug target. We report hybrid structure-based virtual screening to identify small molecules with the potential to interact with the N-terminal domain (NTD) of HIV-1 CA and disrupt early, preintegration steps of the HIV-1 replication cycle. The small molecule 4,4'-[dibenzo[b,d]furan-2,8-diylbis(5-phenyl-1H-imidazole-4,2-diyl)]dibenzoic acid (CK026), which had anti-HIV-1 activity in single- and multiple-round infections but failed to inhibit viral replication in peripheral blood mononuclear cells (PBMCs), was identified. Three analogues of CK026 with reduced size and better drug-like properties were synthesized and assessed. Compound I-XW-053 (4-(4,5-diphenyl-1H-imidazol-2-yl)benzoic acid) retained all of the antiviral activity of the parental compound and inhibited the replication of a diverse panel of primary HIV-1 isolates in PBMCs, while displaying no appreciable cytotoxicity. This antiviral activity was specific to HIV-1, as I-XW-053 displayed no effect on the replication of SIV or against a panel of nonretroviruses. Direct interaction of I-XW-053 was quantified with wild-type and mutant CA protein using surface plasmon resonance and isothermal titration calorimetry. Mutation of Ile37 and Arg173, which are required for interaction with compound I-XW-053, crippled the virus at an early, preintegration step. Using quantitative PCR, we demonstrated that treatment with I-XW-053 inhibited HIV-1 reverse transcription in multiple cell types, indirectly pointing to dysfunction in the uncoating process. In summary, we have identified a CA-specific compound that targets and inhibits a novel region in the NTD-NTD interface, affects uncoating, and possesses broad-spectrum anti-HIV-1 activity.

  6. HIV-1 sub-type C chimaeric VLPs boost cellular immune responses in mice

    PubMed Central

    2010-01-01

    Several approaches have been explored to eradicate HIV; however, a multigene vaccine appears to be the best option, given their proven potential to elicit broad, effective responses in animal models. The Pr55Gag protein is an excellent vaccine candidate in its own right, given that it can assemble into large, enveloped, virus-like particles (VLPs) which are highly immunogenic, and can moreover be used as a scaffold for the presentation of other large non-structural HIV antigens. In this study, we evaluated the potential of two novel chimaeric HIV-1 Pr55Gag-based VLP constructs - C-terminal fusions with reverse transcriptase and a Tat::Nef fusion protein, designated GagRT and GagTN respectively - to enhance a cellular response in mice when used as boost components in two types of heterologous prime-boost vaccine strategies. A vaccine regimen consisting of a DNA prime and chimaeric HIV-1 VLP boosts in mice induced strong, broad cellular immune responses at an optimum dose of 100 ng VLPs. The enhanced cellular responses induced by the DNA prime-VLP boost were two- to three-fold greater than two DNA vaccinations. Moreover, a mixture of GagRT and GagTN VLPs also boosted antigen-specific CD8+ and CD4+ T-cell responses, while VLP vaccinations only induced predominantly robust Gag CD4+ T-cell responses. The results demonstrate the promising potential of these chimaeric VLPs as vaccine candidates against HIV-1. PMID:21087527

  7. Endocytosis-mediated HIV-1 entry and its significance in the elusive behavior of the virus in astrocytes.

    PubMed

    Chauhan, Ashok; Mehla, Rajeev; Vijayakumar, Theophilus Sunder; Handy, Indhira

    2014-05-01

    Astrocytes protect neurons but also evoke a proinflammatory response to injury and viral infections including HIV. We investigated the mechanism of HIV-1 infection in primary astrocytes, which showed minimal but productive viral infection independent of CXCR4. As with ectopic-CD4-expressing astrocytes, lysosomotropic agents led to increased HIV-1 infection in wild-type but not Rabs 5, 7, and 11-ablated astrocytes. Instead, HIV-1 infection was decreased in Rab-depleted astrocytes, corroborating viral entry by endocytosis. HIV-1 produced persistent infection in astrocytes (160 days); no evidence of latent infection was seen. Notably, one caveat is that endosomal modifiers enhanced wild-type HIV-1 infection (M- and T-tropic) in astrocytes, suggesting endocytic entry of the virus. Impeding endocytosis by inhibition of Rab 5, 7 or 11 will inhibit HIV infection in astrocytes. Although the contribution of such low-level infection in astrocytes to neurological complications is unclear, it may serve as an elusive viral reservoir in the central nervous system.

  8. A highly sensitive and specific time resolved fluorometric bridge assay for antibodies to HIV-1 and -2.

    PubMed

    Talha, Sheikh M; Salminen, Teppo; Swaminathan, Sathyamangalam; Soukka, Tero; Pettersson, Kim; Khanna, Navin

    2011-04-01

    This study addresses the continuing need to develop human immunodeficiency virus-1 (HIV-1) and HIV-2 immunoassays with increased sensitivity. Two chimeric antigens, r-HIV-1env, incorporating immunoreactive regions of HIV-1 glycoprotein (gp) 120 and gp41, and r-HIV-2env, incorporating HIV-2 gp125 and gp36, and their corresponding in vivo biotinylated versions, r-Bio-HIV-1env and r-Bio-HIV-2env, were expressed in Escherichia coli and purified by single step affinity chromatography. These antigens were used to set up a bridge assay for the detection of anti-HIV antibodies. Anti-HIV-1 and HIV-2 antibodies in sera were captured using a mixture of the biotinylated antigens, immobilized on streptavidin-coated microtiter wells, and revealed using a mixture of the non-biotinylated antigens, labeled with either Eu(3+) chelate or with nanoparticles doped with the Eu(3+) chelate, followed by fluorescence measurement using time resolved fluorometry (TRF). The performance of this TRF immunoassay was compared to that of five commercial HIV ELISAs using well-characterized sera panels. The results show that the TRF immunoassay using either form of the label was in complete agreement with the commercial assays. The use of the Eu(3+) chelate label enhanced sensitivity significantly when used in the nanoparticle format as evidenced by the very high signal-to-cut-off ratios.

  9. Impact of a decade of successful antiretroviral therapy initiated at HIV-1 seroconversion on blood and rectal reservoirs

    PubMed Central

    Malatinkova, Eva; Spiegelaere, Ward De; Bonczkowski, Pawel; Kiselinova, Maja; Vervisch, Karen; Trypsteen, Wim; Johnson, Margaret; Verhofstede, Chris; de Looze, Danny; Murray, Charles; Loes, Sabine Kinloch-de; Vandekerckhove, Linos

    2015-01-01

    Persistent reservoirs remain the major obstacles to achieve an HIV-1 cure. Prolonged early antiretroviral therapy (ART) may reduce the extent of reservoirs and allow for virological control after ART discontinuation. We compared HIV-1 reservoirs in a cross-sectional study using polymerase chain reaction-based techniques in blood and tissue of early-treated seroconverters, late-treated patients, ART-naïve seroconverters, and long-term non-progressors (LTNPs) who have spontaneous virological control without treatment. A decade of early ART reduced the total and integrated HIV-1 DNA levels compared with later treatment initiation, but not reaching the low levels found in LTNPs. Total HIV-1 DNA in rectal biopsies did not differ between cohorts. Importantly, lower viral transcription (HIV-1 unspliced RNA) and enhanced immune preservation (CD4/CD8), reminiscent of LTNPs, were found in early compared to late-treated patients. This suggests that early treatment is associated with some immunovirological features of LTNPs that may improve the outcome of future interventions aimed at a functional cure. DOI: http://dx.doi.org/10.7554/eLife.09115.001 PMID:26439007

  10. HIV-1 VACCINES. Diversion of HIV-1 vaccine-induced immunity by gp41-microbiota cross-reactive antibodies.

    PubMed

    Williams, Wilton B; Liao, Hua-Xin; Moody, M Anthony; Kepler, Thomas B; Alam, S Munir; Gao, Feng; Wiehe, Kevin; Trama, Ashley M; Jones, Kathryn; Zhang, Ruijun; Song, Hongshuo; Marshall, Dawn J; Whitesides, John F; Sawatzki, Kaitlin; Hua, Axin; Liu, Pinghuang; Tay, Matthew Z; Seaton, Kelly E; Shen, Xiaoying; Foulger, Andrew; Lloyd, Krissey E; Parks, Robert; Pollara, Justin; Ferrari, Guido; Yu, Jae-Sung; Vandergrift, Nathan; Montefiori, David C; Sobieszczyk, Magdalena E; Hammer, Scott; Karuna, Shelly; Gilbert, Peter; Grove, Doug; Grunenberg, Nicole; McElrath, M Juliana; Mascola, John R; Koup, Richard A; Corey, Lawrence; Nabel, Gary J; Morgan, Cecilia; Churchyard, Gavin; Maenza, Janine; Keefer, Michael; Graham, Barney S; Baden, Lindsey R; Tomaras, Georgia D; Haynes, Barton F

    2015-08-14

    An HIV-1 DNA prime vaccine, with a recombinant adenovirus type 5 (rAd5) boost, failed to protect from HIV-1 acquisition. We studied the nature of the vaccine-induced antibody (Ab) response to HIV-1 envelope (Env). HIV-1-reactive plasma Ab titers were higher to Env gp41 than to gp120, and repertoire analysis demonstrated that 93% of HIV-1-reactive Abs from memory B cells responded to Env gp41. Vaccine-induced gp41-reactive monoclonal antibodies were non-neutralizing and frequently polyreactive with host and environmental antigens, including intestinal microbiota (IM). Next-generation sequencing of an immunoglobulin heavy chain variable region repertoire before vaccination revealed an Env-IM cross-reactive Ab that was clonally related to a subsequent vaccine-induced gp41-reactive Ab. Thus, HIV-1 Env DNA-rAd5 vaccine induced a dominant IM-polyreactive, non-neutralizing gp41-reactive Ab repertoire response that was associated with no vaccine efficacy.

  11. Cell-specific RNA aptamer against human CCR5 specifically targets HIV-1 susceptible cells and inhibits HIV-1 infectivity.

    PubMed

    Zhou, Jiehua; Satheesan, Sangeetha; Li, Haitang; Weinberg, Marc S; Morris, Kevin V; Burnett, John C; Rossi, John J

    2015-03-19

    The C-C chemokine receptor type 5 (CCR5) is a receptor expressed by T cells and macrophages that serves as a coreceptor for macrophage-tropic HIV-1. Loss of CCR5 is associated with resistance to HIV-1. Here, we combine the live-cell-based SELEX with high-throughput sequencing technology to generate CCR5 RNA aptamers capable of specifically targeting HIV-1 susceptible cells (as small interfering RNA [siRNA] delivery agent) and inhibiting HIV-1 infectivity (as antiviral agent) via block of the CCR5 required for HIV-1 to enter cells. One of the best candidates, G-3, efficiently bound and was internalized into human CCR5-expressing cells. The G-3 specifically neutralized R5 virus infection in primary peripheral blood mononuclear cells, and in vivo generated human CD4(+) T cells with a nanomolar inhibitory concentration 50%. G-3 was also capable of transferring functional siRNAs to CCR5-expressing cells. Collectively, the cell-specific, internalizing, CCR5-targeted aptamers and aptamer-siRNA conjugates offer promise for overcoming some of the current challenges of drug resistance in HIV-1 by providing cell-type- or tissue-specific delivery of various therapeutic moieties.

  12. Cell-specific RNA aptamer against human CCR5 specifically targets HIV-1 susceptible and inhibits HIV-1 infectivity

    PubMed Central

    Zhou, Jiehua; Satheesan, Sangeetha; Li, Haitang; Weinberg, Marc S.; Morris, Kevin V.; Burnett, John; Rossi, John

    2015-01-01

    SUMMARY The C-C chemokine receptor type 5 (CCR5) is a receptor expressed by T-cells and macrophages that serves as a co-receptor for macrophage-tropic HIV-1. Loss of CCR5 is associated with resistance to HIV-1. Here we combine the live cell-based SELEX with high throughput sequencing technology to generate CCR5 RNA aptamers capable of specifically targeting HIV-1 susceptible cells (as siRNA delivery agent) and inhibiting HIV-1 infectivity (as antiviral agent) via block of the CCR5 required for HIV-1 to enter cells. One of the best candidates, G-3, efficiently bound and was internalized into human CCR5 expressing cells. The G-3 specifically neutralized R5 virus infection in primary peripheral blood mononuclear cells, and in vivo generated human CD4+ T cells with a nanomolar IC50. G-3 was also capable of transferring functional siRNAs to CCR5 expressing cells. Collectively, the cell-specific, internalizing, CCR5-targeted aptamers and aptamer-siRNA conjugates offer promise for overcoming some of the current challenges of drug resistance in HIV-1 by providing cell-type- or tissue-specific delivery of various therapeutic moieties. PMID:25754473

  13. Impact of HIV-1 Membrane Cholesterol on Cell-Independent Lytic Inactivation and Cellular Infectivity.

    PubMed

    Kalyana Sundaram, Ramalingam Venkat; Li, Huiyuan; Bailey, Lauren; Rashad, Adel A; Aneja, Rachna; Weiss, Karl; Huynh, James; Bastian, Arangaserry Rosemary; Papazoglou, Elisabeth; Abrams, Cameron; Wrenn, Steven; Chaiken, Irwin

    2016-01-26

    Peptide triazole thiols (PTTs) have been found previously to bind to HIV-1 Env spike gp120 and cause irreversible virus inactivation by shedding gp120 and lytically releasing luminal capsid protein p24. Since the virions remain visually intact, lysis appears to occur via limited membrane destabilization. To better understand the PTT-triggered membrane transformation involved, we investigated the role of envelope cholesterol on p24 release by measuring the effect of cholesterol depletion using methyl beta-cyclodextrin (MβCD). An unexpected bell-shaped response of PTT-induced lysis to [MβCD] was observed, involving lysis enhancement at low [MβCD] vs loss of function at high [MβCD]. The impact of cholesterol depletion on PTT-induced lysis was reversed by adding exogenous cholesterol and other sterols that support membrane rafts, while sterols that do not support rafts induced only limited reversal. Cholesterol depletion appears to cause a reduced energy barrier to lysis as judged by decreased temperature dependence with MβCD. Enhancement/replenishment responses to [MβCD] also were observed for HIV-1 infectivity, consistent with a similar energy barrier effect in the membrane transformation of virus cell fusion. Overall, the results argue that cholesterol in the HIV-1 envelope is important for balancing virus stability and membrane transformation, and that partial depletion, while increasing infectivity, also makes the virus more fragile. The results also reinforce the argument that the lytic inactivation and infectivity processes are mechanistically related and that membrane transformations occurring during lysis can provide an experimental window to investigate membrane and protein factors important for HIV-1 cell entry.

  14. Cocaine promotes both initiation and elongation phase of HIV-1 transcription by activating NF-κB and MSK1 and inducing selective epigenetic modifications at HIV-1 LTR

    SciTech Connect

    Sahu, Geetaram; Farley, Kalamo; El-Hage, Nazira; Aiamkitsumrit, Benjamas; Fassnacht, Ryan; Kashanchi, Fatah; Ochem, Alex; Simon, Gary L.; Karn, Jonathan; Hauser, Kurt F.; Tyagi, Mudit

    2015-09-15

    Cocaine accelerates human immunodeficiency virus (HIV-1) replication by altering specific cell-signaling and epigenetic pathways. We have elucidated the underlying molecular mechanisms through which cocaine exerts its effect in myeloid cells, a major target of HIV-1 in central nervous system (CNS). We demonstrate that cocaine treatment promotes HIV-1 gene expression by activating both nuclear factor-kappa B (NF-ĸB) and mitogen- and stress-activated kinase 1 (MSK1). MSK1 subsequently catalyzes the phosphorylation of histone H3 at serine 10, and p65 subunit of NF-ĸB at 276th serine residue. These modifications enhance the interaction of NF-ĸB with P300 and promote the recruitment of the positive transcription elongation factor b (P-TEFb) to the HIV-1 LTR, supporting the development of an open/relaxed chromatin configuration, and facilitating the initiation and elongation phases of HIV-1 transcription. Results are also confirmed in primary monocyte derived macrophages (MDM). Overall, our study provides detailed insights into cocaine-driven HIV-1 transcription and replication. - Highlights: • Cocaine induces the initiation phase of HIV transcription by activating NF-ĸB. • Cocaine induced NF-ĸB phosphorylation promotes its interaction with P300. • Cocaine enhances the elongation phase of HIV transcription by stimulating MSK1. • Cocaine activated MSK1 catalyzes the phosphorylation of histone H3 at its Ser10. • Cocaine induced H3S10 phosphorylation facilitates the recruitment of P-TEFb at LTR.

  15. HIV-1 Infection-Induced Suppression of the Let-7i/IL-2 Axis Contributes to CD4+ T Cell Death

    PubMed Central

    Zhang, Yijun; Yin, Yue; Zhang, Shaoying; Luo, Haihua; Zhang, Hui

    2016-01-01

    The mechanisms underlying HIV-1-mediated CD4+ T cell depletion are highly complicated. Interleukin-2 (IL-2) is a key cytokine that maintains the survival and proliferation of activated CD4+ T cells. IL-2 levels are disturbed during HIV-1 infection, but the underlying mechanism(s) requires further investigation. We have reported that cellular microRNA (miRNA) let-7i upregulates IL-2 expression by targeting the promoter TATA-box region, which functions as a positive regulator. In this study, we found that HIV-1 infection decreases the expression of let-7i in CD4+ T cells by attenuating its promoter activity. The reduced let-7i miRNA expression led to a decline in IL-2 levels. A let-7i mimic increased IL-2 expression and subsequently enhanced the resistance of CD4+ T cells to HIV-1-induced apoptosis. By contrast, the blockage of let-7i with a specific inhibitor resulted in elevated CD4+ T cell apoptosis during HIV-1 infection. Furthermore, by knocking down the expression of IL-2, we found that the let-7i-mediated CD4+ T cell resistance to apoptosis during HIV-1 infection was dependent on IL-2 signaling rather than an alternative CD95-mediated cell-death pathway. Taken together, our findings reveal a novel pathway for HIV-1-induced dysregulation of IL-2 cytokines and depletion of CD4+ T-lymphocytes. PMID:27145859

  16. CRISPR/gRNA-directed synergistic activation mediator (SAM) induces specific, persistent and robust reactivation of the HIV-1 latent reservoirs

    PubMed Central

    Zhang, Yonggang; Yin, Chaoran; Zhang, Ting; Li, Fang; Yang, Wensheng; Kaminski, Rafal; Fagan, Philip Regis; Putatunda, Raj; Young, Won-Bin; Khalili, Kamel; Hu, Wenhui

    2015-01-01

    Current antiretroviral therapy does not eliminate the integrated and transcriptionally silent HIV-1 provirus in latently infected cells. Recently, a “shock and kill” strategy has been extensively explored to eradicate the HIV-1 latent reservoirs for a permanent cure of AIDS. The therapeutic efficacy of currently used agents remains disappointing because of low efficiency, non-specificity and cellular toxicity. Here we present a novel catalytically-deficient Cas9-synergistic activation mediator (dCas9-SAM) technology to selectively, potently and persistently reactivate the HIV-1 latent reservoirs. By screening 16 MS2-mediated single guide RNAs, we identified long terminal repeat (LTR)-L and O that surround the enhancer region (-165/-145 for L and -92/-112 for O) and induce robust reactivation of HIV-1 provirus in HIV-1 latent TZM-bI epithelial, Jurkat T lymphocytic and CHME5 microglial cells. This compulsory reactivation induced cellular suicide via toxic buildup of viral proteins within HIV-1 latent Jurkat T and CHME5 microglial cells. These results suggest that this highly effective and target-specific dCas9-SAM system can serve as a novel HIV-latency-reversing therapeutic tool for the permanent elimination of HIV-1 latent reservoirs. PMID:26538064

  17. Innate Invariant NKT Cell Recognition of HIV-1–Infected Dendritic Cells Is an Early Detection Mechanism Targeted by Viral Immune Evasion

    PubMed Central

    Paquin-Proulx, Dominic; Gibbs, Anna; Bächle, Susanna M.; Checa, Antonio; Introini, Andrea; Leeansyah, Edwin; Wheelock, Craig E.; Nixon, Douglas F.; Broliden, Kristina; Tjernlund, Annelie; Moll, Markus

    2016-01-01

    Invariant NKT (iNKT) cells are innate-like T cells that respond rapidly with a broad range of effector functions upon recognition of glycolipid Ags presented by CD1d. HIV-1 carries Nef- and Vpu-dependent mechanisms to interfere with CD1d surface expression, indirectly suggesting a role for iNKT cells in control of HIV-1 infection. In this study, we investigated whether iNKT cells can participate in the innate cell–mediated immune response to HIV-1. Infection of dendritic cells (DCs) with Nef- and Vpu-deficient HIV-1 induced upregulation of CD1d in a TLR7-dependent manner. Infection of DCs caused modulation of enzymes in the sphingolipid pathway and enhanced expression of the endogenous glucosylceramide Ag. Importantly, iNKT cells responded specifically to rare DCs productively infected with Nef- and Vpu-defective HIV-1. Transmitted founder viral isolates differed in their CD1d downregulation capacity, suggesting that diverse strains may be differentially successful in inhibiting this pathway. Furthermore, both iNKT cells and DCs expressing CD1d and HIV receptors resided in the female genital mucosa, a site where HIV-1 transmission occurs. Taken together, these findings suggest that innate iNKT cell sensing of HIV-1 infection in DCs is an early immune detection mechanism, which is independent of priming and adaptive recognition of viral Ag, and is actively targeted by Nef- and Vpu-dependent viral immune evasion mechanisms. PMID:27481843

  18. Kaposi's-sarcoma-associated-herpesvirus-activated dendritic cells promote HIV-1 trans-infection and suppress CD4{sup +} T cell proliferation

    SciTech Connect

    Liu, Wan; Qin, Yan; Bai, Lei; Lan, Ke; Wang, Jian-Hua

    2013-06-05

    Infection of Kaposi's sarcoma-associated herpesvirus (KSHV) is commonly occurred in AIDS patients. KSHV and HIV-1 act cooperatively in regulating infection with each other and in human carcinogenesis. Dendritic cells (DCs), as the pivotal cells in host immunity, may be modulated by both viruses, for immunoevasion and dissemination, therefore, the interaction between DCs and each virus has been a prior focus for pathogenesis elucidation. Here, we assessed the potential effect of KSHV on DC–HIV-1 interaction. We found that KSHV stimulation could promote maturation of monocyte-derived DCs (MDDCs) and impaired the ability of MDDCs to drive proliferation of resting CD4{sup +} T cells, demonstrating the immunosuppression induced by KSHV. More importantly, KSHV-stimulated MDDCs could capture more HIV-1 and efficiently transferred these infectious viruses to Hut/CCR5 T cell line. Our results reveal the novel modulation of DC-mediated HIV-1 dissemination by KSHV, and highlight the importance of studying DC–HIV-1 interaction to elucidate HIV/AIDS pathogenesis. - Highlights: ► KSHV impaired the ability of MDDCs to drive proliferation of resting CD4{sup +} T cells. ► KSHV stimulation matured MDDCs and enhanced HIV-1 endocytosis. ► KSHV stimulated MDDCs increased ICAM-1 expression and tighten contact with T cells. ► KSHV-stimulated MDDCs promoted HIV-1 trans-infection of CD4{sup +} T cells.

  19. Innate Invariant NKT Cell Recognition of HIV-1-Infected Dendritic Cells Is an Early Detection Mechanism Targeted by Viral Immune Evasion.

    PubMed

    Paquin-Proulx, Dominic; Gibbs, Anna; Bächle, Susanna M; Checa, Antonio; Introini, Andrea; Leeansyah, Edwin; Wheelock, Craig E; Nixon, Douglas F; Broliden, Kristina; Tjernlund, Annelie; Moll, Markus; Sandberg, Johan K

    2016-09-01

    Invariant NKT (iNKT) cells are innate-like T cells that respond rapidly with a broad range of effector functions upon recognition of glycolipid Ags presented by CD1d. HIV-1 carries Nef- and Vpu-dependent mechanisms to interfere with CD1d surface expression, indirectly suggesting a role for iNKT cells in control of HIV-1 infection. In this study, we investigated whether iNKT cells can participate in the innate cell-mediated immune response to HIV-1. Infection of dendritic cells (DCs) with Nef- and Vpu-deficient HIV-1 induced upregulation of CD1d in a TLR7-dependent manner. Infection of DCs caused modulation of enzymes in the sphingolipid pathway and enhanced expression of the endogenous glucosylceramide Ag. Importantly, iNKT cells responded specifically to rare DCs productively infected with Nef- and Vpu-defective HIV-1. Transmitted founder viral isolates differed in their CD1d downregulation capacity, suggesting that diverse strains may be differentially successful in inhibiting this pathway. Furthermore, both iNKT cells and DCs expressing CD1d and HIV receptors resided in the female genital mucosa, a site where HIV-1 transmission occurs. Taken together, these findings suggest that innate iNKT cell sensing of HIV-1 infection in DCs is an early immune detection mechanism, which is independent of priming and adaptive recognition of viral Ag, and is actively targeted by Nef- and Vpu-dependent viral immune evasion mechanisms.

  20. ZNF10 inhibits HIV-1 LTR activity through interaction with NF-κB and Sp1 binding motifs.

    PubMed

    Nishitsuji, Hironori; Sawada, Leila; Sugiyama, Ryuichi; Takaku, Hiroshi

    2015-07-01

    Kruppel-associated box-containing zinc finger (KRAB-ZNF) genes constitute the single largest gene family of transcriptional repressors in the genomes of higher organisms. In this study, we isolated 52 cDNA clones of KRAB-ZFPs from U1 cell lines and screened them to identify which were capable of regulating HIV-1 gene expression. We identified 5 KRAB-ZFPs that suppressed ⩾50% of HIV-1 LTR. Of the 5 identified KRAB-ZFPs, the expression of ZNF10 significantly enhanced the transcriptional repression activity of the LTR compared with other ZNFs. In addition, the depletion of endogenous ZNF10 led to the activation of HIV-1 LTR. The repressor activity of ZNF10 was required for TRIM28, SETDB1 and HP1-gamma binding. These results indicate that ZNF10 could be involved in a potent intrinsic antiretroviral defense. PMID:26096782

  1. HIV-1 Vpr Protein Inhibits Telomerase Activity via the EDD-DDB1-VPRBP E3 Ligase Complex*

    PubMed Central

    Wang, Xin; Singh, Shailbala; Jung, Hae-Yun; Yang, Guojun; Jun, Sohee; Sastry, K. Jagannadha; Park, Jae-Il

    2013-01-01

    Viral pathogens utilize host cell machinery for their benefits. Herein, we identify that HIV-1 Vpr (viral protein R) negatively modulates telomerase activity. Telomerase enables stem and cancer cells to evade cell senescence by adding telomeric sequences to the ends of chromosomes. We found that Vpr inhibited telomerase activity by down-regulating TERT protein, a catalytic subunit of telomerase. As a molecular adaptor, Vpr enhanced the interaction between TERT and the VPRBP substrate receptor of the DYRK2-associated EDD-DDB1-VPRBP E3 ligase complex, resulting in increased ubiquitination of TERT. In contrast, the Vpr mutant identified in HIV-1-infected long-term nonprogressors failed to promote TERT destabilization. Our results suggest that Vpr inhibits telomerase activity by hijacking the host E3 ligase complex, and we propose the novel molecular mechanism of telomerase deregulation in possibly HIV-1 pathogenesis. PMID:23612978

  2. The strength of the HIV-1 3' splice sites affects Rev function

    PubMed Central

    Kammler, Susanne; Otte, Marianne; Hauber, Ilona; Kjems, Jørgen; Hauber, Joachim; Schaal, Heiner

    2006-01-01

    Background The HIV-1 Rev protein is a key component in the early to late switch in HIV-1 splicing from early intronless (e.g. tat, rev) to late intron-containing Rev-dependent (e.g. gag, vif, env) transcripts. Previous results suggested that cis-acting sequences and inefficient 5' and 3' splice sites are a prerequisite for Rev function. However, we and other groups have shown that two of the HIV-1 5' splice sites, D1 and D4, are efficiently used in vitro and in vivo. Here, we focus on the efficiency of the HIV-1 3' splice sites taking into consideration to what extent their intrinsic efficiencies are modulated by their downstream cis-acting exonic sequences. Furthermore, we delineate their role in RNA stabilization and Rev function. Results In the presence of an efficient upstream 5' splice site the integrity of the 3' splice site is not essential for Rev function whereas an efficient 3' splice site impairs Rev function. The detrimental effect of a strong 3' splice site on the amount of Rev-dependent intron-containing HIV-1 glycoprotein coding (env) mRNA is not compensatable by weakening the strength of the upstream 5' splice site. Swapping the HIV-1 3' splice sites in an RRE-containing minigene, we found a 3' splice site usage which was variably dependent on the presence of the usual downstream exonic sequence. The most evident activation of 3' splice site usage by its usual downstream exonic sequence was observed for 3' splice site A1 which was turned from an intrinsic very weak 3' splice site into the most active 3' splice site, even abolishing Rev activity. Performing pull-down experiments with nuclear extracts of HeLa cells we identified a novel ASF/SF2-dependent exonic splicing enhancer (ESE) within HIV-1 exon 2 consisting of a heptameric sequence motif occurring twice (M1 and M2) within this short non-coding leader exon. Single point mutation of M1 within an infectious molecular clone is detrimental for HIV-1 exon 2 recognition without affecting Rev

  3. HIV-1 evades innate immune recognition through specific cofactor recruitment

    NASA Astrophysics Data System (ADS)

    Rasaiyaah, Jane; Tan, Choon Ping; Fletcher, Adam J.; Price, Amanda J.; Blondeau, Caroline; Hilditch, Laura; Jacques, David A.; Selwood, David L.; James, Leo C.; Noursadeghi, Mahdad; Towers, Greg J.

    2013-11-01

    Human immunodeficiency virus (HIV)-1 is able to replicate in primary human macrophages without stimulating innate immunity despite reverse transcription of genomic RNA into double-stranded DNA, an activity that might be expected to trigger innate pattern recognition receptors. We reasoned that if correctly orchestrated HIV-1 uncoating and nuclear entry is important for evasion of innate sensors then manipulation of specific interactions between HIV-1 capsid and host factors that putatively regulate these processes should trigger pattern recognition receptors and stimulate type 1 interferon (IFN) secretion. Here we show that HIV-1 capsid mutants N74D and P90A, which are impaired for interaction with cofactors cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and cyclophilins (Nup358 and CypA), respectively, cannot replicate in primary human monocyte-derived macrophages because they trigger innate sensors leading to nuclear translocation of NF-κB and IRF3, the production of soluble type 1 IFN and induction of an antiviral state. Depletion of CPSF6 with short hairpin RNA expression allows wild-type virus to trigger innate sensors and IFN production. In each case, suppressed replication is rescued by IFN-receptor blockade, demonstrating a role for IFN in restriction. IFN production is dependent on viral reverse transcription but not integration, indicating that a viral reverse transcription product comprises the HIV-1 pathogen-associated molecular pattern. Finally, we show that we can pharmacologically induce wild-type HIV-1 infection to stimulate IFN secretion and an antiviral state using a non-immunosuppressive cyclosporine analogue. We conclude that HIV-1 has evolved to use CPSF6 and cyclophilins to cloak its replication, allowing evasion of innate immune sensors and induction of a cell-autonomous innate immune response in primary human macrophages.

  4. HIV-1, methamphetamine and astrocytes at neuroinflammatory Crossroads

    PubMed Central

    Borgmann, Kathleen; Ghorpade, Anuja

    2015-01-01

    As a popular psychostimulant, methamphetamine (METH) use leads to long-lasting, strong euphoric effects. While METH abuse is common in the general population, between 10 and 15% of human immunodeficiency virus-1 (HIV-1) patients report having abused METH. METH exacerbates the severity and onset of HIV-1-associated neurocognitive disorders (HAND) through direct and indirect mechanisms. Repetitive METH use impedes adherence to antiretroviral drug regimens, increasing the likelihood of HIV-1 disease progression toward AIDS. METH exposure also directly affects both innate and adaptive immunity, altering lymphocyte numbers and activity, cytokine signaling, phagocytic function and infiltration through the blood brain barrier. Further, METH triggers the dopamine reward pathway and leads to impaired neuronal activity and direct toxicity. Concurrently, METH and HIV-1 alter the neuroimmune balance and induce neuroinflammation, which modulates a wide range of brain functions including neuronal signaling and activity, glial activation, viral infection, oxidative stress, and excitotoxicity. Pathologically, reactive gliosis is a hallmark of both HIV-1- and METH-associated neuroinflammation. Significant commonality exists in the neurotoxic mechanisms for both METH and HAND; however, the pathways dysregulated in astroglia during METH exposure are less clear. Thus, this review highlights alterations in astrocyte intracellular signaling pathways, gene expression and function during METH and HIV-1 comorbidity, with special emphasis on HAND-associated neuroinflammation. Importantly, this review carefully evaluates interventions targeting astrocytes in HAND and METH as potential novel therapeutic approaches. This comprehensive overview indicates, without a doubt, that during HIV-1 infection and METH abuse, a complex dialog between all neural cells is orchestrated through astrocyte regulated neuroinflammation. PMID:26579077

  5. Phylodynamics of the HIV-1 epidemic in Cuba.

    PubMed

    Delatorre, Edson; Bello, Gonzalo

    2013-01-01

    Previous studies have shown that the HIV-1 epidemic in Cuba displayed a complex molecular epidemiologic profile with circulation of several subtypes and circulating recombinant forms (CRF); but the evolutionary and population history of those viral variants remains unknown. HIV-1 pol sequences of the most prevalent Cuban lineages (subtypes B, C and G, CRF18_cpx, CRF19_cpx, and CRFs20/23/24_BG) isolated between 1999 and 2011 were analyzed. Maximum-likelihood analyses revealed multiple introductions of subtype B (n≥66), subtype C (n≥10), subtype G (n≥8) and CRF18_cpx (n≥2) viruses in Cuba. The bulk of HIV-1 infections in this country, however, was caused by dissemination of a few founder strains probably introduced from North America/Europe (clades B(CU-I) and B(CU-II)), east Africa (clade C(CU-I)) and central Africa (clades G(CU), CRF18(CU) and CRF19(CU)), or locally generated (clades CRFs20/23/24_BG). Bayesian-coalescent analyses show that the major HIV-1 founder strains were introduced into Cuba during 1985-1995; whereas the CRFs_BG strains emerged in the second half of the 1990s. Most HIV-1 Cuban clades appear to have experienced an initial period of fast exponential spread during the 1990s and early 2000s, followed by a more recent decline in growth rate. The median initial growth rate of HIV-1 Cuban clades ranged from 0.4 year⁻¹ to 1.6 year⁻¹. Thus, the HIV-1 epidemic in Cuba has been a result of the successful introduction of a few viral strains that began to circulate at a rather late time of the AIDS pandemic, but then were rapidly disseminated through local transmission networks.

  6. Sensing of HIV-1 Infection in Tzm-bl Cells with Reconstituted Expression of STING

    PubMed Central

    Trotard, Maud; Tsopoulidis, Nikolaos; Tibroni, Nadine; Willemsen, Joschka; Binder, Marco; Ruggieri, Alessia

    2015-01-01

    ABSTRACT Production of proinflammatory cytokines indicative of potent recognition by the host innate immune system has long been recognized as a hallmark of the acute phase of HIV-1 infection. The first components of the machinery by which primary HIV target cells sense infection have recently been described; however, the mechanistic dissection of innate immune recognition and viral evasion would be facilitated by an easily accessible cell line model. Here we describe that reconstituted expression of the innate signaling adaptor STING enhanced the ability of the well-established HIV reporter cell line Tzm-bl to sense HIV infection and to convert this information into nuclear translocation of IRF3 as well as expression of cytokine mRNA. STING-dependent immune sensing of HIV-1 required virus entry and reverse transcription but not genome integration. Particularly efficient recognition was observed for an HIV-1 variant lacking expression of the accessory protein Vpr, suggesting a role of the viral protein in circumventing STING-mediated immune signaling. Vpr as well as STING significantly impacted the magnitude and breadth of the cytokine mRNA expression profile induced upon HIV-1 infection. However, cytoplasmic DNA sensing did not result in detectable cytokine secretion in this cell system, and innate immune recognition did not affect infection rates. Despite these deficits in eliciting antiviral effector functions, these results establish Tzm-bl STING and Tzm-bl STING IRF3.GFP cells as useful tools for studies aimed at dissecting mechanisms and regulation of early innate immune recognition of HIV infection. IMPORTANCE Cell-autonomous immune recognition of HIV infection was recently established as an important aspect by which the host immune system attempts to fend off HIV-1 infection. Mechanistic studies on host cell recognition and viral evasion are hampered by the resistance of many primary HIV target cells to detailed experimental manipulation. We describe here

  7. HIV-1 and Its gp120 Inhibits the Influenza A(H1N1)pdm09 Life Cycle in an IFITM3-Dependent Fashion

    PubMed Central

    Mesquita, Milene; Fintelman-Rodrigues, Natalia; Sacramento, Carolina Q.; Abrantes, Juliana L.; Costa, Eduardo; Temerozo, Jairo R.; Siqueira, Marilda M.; Bou-Habib, Dumith Chequer; Souza, Thiago Moreno L.

    2014-01-01

    HIV-1-infected patients co-infected with A(H1N1)pdm09 surprisingly presented benign clinical outcome. The knowledge that HIV-1 changes the host homeostatic equilibrium, which may favor the patient resistance to some co-pathogens, prompted us to investigate whether HIV-1 infection could influence A(H1N1)pdm09 life cycle in vitro. We show here that exposure of A(H1N1)pdm09-infected epithelial cells to HIV-1 viral particles or its gp120 enhanced by 25% the IFITM3 content, resulting in a decrease in influenza replication. This event was dependent on toll-like receptor 2 and 4. Moreover, knockdown of IFITM3 prevented HIV-1 ability to inhibit A(H1N1)pdm09 replication. HIV-1 infection also increased IFITM3 levels in human primary macrophages by almost 100%. Consequently, the arrival of influenza ribonucleoproteins (RNPs) to nucleus of macrophages was inhibited, as evaluated by different approaches. Reduction of influenza RNPs entry into the nucleus tolled A(H1N1)pdm09 life cycle in macrophages earlier than usual, limiting influenza's ability to induce TNF-α. As judged by analysis of the influenza hemagglutin (HA) gene from in vitro experiments and from samples of HIV-1/A(H1N1)pdm09 co-infected individuals, the HIV-1-induced reduction of influenza replication resulted in delayed viral evolution. Our results may provide insights on the mechanisms that may have attenuated the clinical course of Influenza in HIV-1/A(H1N1)pdm09 co-infected patients during the recent influenza form 2009/2010. PMID:24978204

  8. Large-scale analysis of the prevalence and geographic distribution of HIV-1 non-B variants in the United States.

    PubMed

    Pyne, Michael T; Hackett, John; Holzmayer, Vera; Hillyard, David R

    2013-08-01

    The genetic diversity of human immunodeficiency virus type 1 (HIV-1) has significant implications for diagnosis, vaccine development, and clinical management of patients. Although HIV-1 subtype B is predominant in the United States, factors such as global travel, immigration, and military deployment have the potential to increase the proportion of non-subtype B infections. Limited data are available on the prevalence and distribution of non-B HIV-1 strains in the United States. We sought to retrospectively examine the prevalence, geographic distribution, diversity, and temporal trends of HIV-1 non-B infections in samples obtained by ARUP Laboratories, a national reference laboratory, from all regions of the United States. HIV-1 pol sequences from 24,386 specimens collected from 46 states between 2004 and September 2011 for drug resistance genotyping were analyzed using the REGA HIV-1 Subtyping Tool, version 2.0. Sequences refractory to subtype determination or reported as non-subtype B by this tool were analyzed by PHYLIP version 3.5 and Simplot version 3.5.1. Non-subtype B strains accounted for 3.27% (798/24,386) of specimens. The 798 non-B specimens were received from 37 states and included 5 subtypes, 23 different circulating recombinant forms (CRFs), and 39 unique recombinant forms (URFs). The non-subtype B prevalence varied from 0% in 2004 (0/54) to 4.12% in 2011 (201/4,884). This large-scale analysis reveals that the diversity of HIV-1 in the United States is high, with multiple subtypes, CRFs, and URFs circulating. Moreover, the geographic distribution of non-B variants is widespread. Data from HIV-1 drug resistance testing have the potential to significantly enhance the surveillance of HIV-1 variants in the United States.

  9. Large-scale analysis of the prevalence and geographic distribution of HIV-1 non-B variants in the United States.

    PubMed

    Pyne, Michael T; Hackett, John; Holzmayer, Vera; Hillyard, David R

    2013-08-01

    The genetic diversity of human immunodeficiency virus type 1 (HIV-1) has significant implications for diagnosis, vaccine development, and clinical management of patients. Although HIV-1 subtype B is predominant in the United States, factors such as global travel, immigration, and military deployment have the potential to increase the proportion of non-subtype B infections. Limited data are available on the prevalence and distribution of non-B HIV-1 strains in the United States. We sought to retrospectively examine the prevalence, geographic distribution, diversity, and temporal trends of HIV-1 non-B infections in samples obtained by ARUP Laboratories, a national reference laboratory, from all regions of the United States. HIV-1 pol sequences from 24,386 specimens collected from 46 states between 2004 and September 2011 for drug resistance genotyping were analyzed using the REGA HIV-1 Subtyping Tool, version 2.0. Sequences refractory to subtype determination or reported as non-subtype B by this tool were analyzed by PHYLIP version 3.5 and Simplot version 3.5.1. Non-subtype B strains accounted for 3.27% (798/24,386) of specimens. The 798 non-B specimens were received from 37 states and included 5 subtypes, 23 different circulating recombinant forms (CRFs), and 39 unique recombinant forms (URFs). The non-subtype B prevalence varied from 0% in 2004 (0/54) to 4.12% in 2011 (201/4,884). This large-scale analysis reveals that the diversity of HIV-1 in the United States is high, with multiple subtypes, CRFs, and URFs circulating. Moreover, the geographic distribution of non-B variants is widespread. Data from HIV-1 drug resistance testing have the potential to significantly enhance the surveillance of HIV-1 variants in the United States. PMID:23761148

  10. HIV-1 functional cure: will the dream come true?

    PubMed

    Liu, Chao; Ma, Xiancai; Liu, Bingfeng; Chen, Cancan; Zhang, Hui

    2015-11-20

    The reservoir of human immunodeficiency virus type 1 (HIV-1), a long-lived pool of latently infected cells harboring replication-competent viruses, is the major obstacle to curing acquired immune deficiency syndrome (AIDS). Although the combination antiretroviral therapy (cART) can successfully suppress HIV-1 viremia and significantly delay the progression of the disease, it cannot eliminate the viral reservoir and the patient must continue to take anti-viral medicines for life. Currently, the appearance of the 'Berlin patient', the 'Boston patients', and the 'Mississippi baby' have inspired many therapeutic strategies for HIV-1 aimed at curing efforts. However, the specific eradication of viral latency and the recovery and optimization of the HIV-1-specific immune surveillance are major challenges to achieving such a cure. Here, we summarize recent studies addressing the mechanisms underlying the viral latency and define two categories of viral reservoir: 'shallow' and 'deep'. We also present the current strategies and recent advances in the development of a functional cure for HIV-1, focusing on full/partial replacement of the immune system, 'shock and kill', and 'permanent silencing' approaches.

  11. The HIV-1 transgenic rat model of neuroHIV

    PubMed Central

    Vigorito, Michael; Connaghan, Kaitlyn P.; Chang, Sulie L.

    2016-01-01

    Despite the ability of current combination anti-retroviral therapy (cART) to limit the progression of HIV-1 to AIDS, HIV-positive individuals continue to experience neuroHIV in the form of HIV-associated neurological disorders (HAND), which can range from subtle to substantial neurocognitive impairment. NeuroHIV may also influence substance use, abuse, and dependence in HIV-positive individuals. Because of the nature of the virus, variables such as mental health co-morbidities make it difficult to study the interaction between HIV and substance abuse in human populations. Several rodent models have been developed in an attempt to study the transmission and pathogenesis of the HIV-1 virus. The HIV-1 transgenic (HIV-1Tg) rat is a reliable model of neuroHIV because it mimics the condition of HIV-infected patients on cART. Research using this model supports the hypothesis that the presence of HIV-1 viral proteins in the central nervous system increases the sensitivity and susceptibility of HIV-positive individuals to substance abuse. PMID:25733103

  12. Characterization of HIV-1 Resistance to Tenofovir Alafenamide In Vitro.

    PubMed

    Margot, Nicolas A; Johnson, Audun; Miller, Michael D; Callebaut, Christian

    2015-10-01

    Tenofovir alafenamide (TAF) is an investigational prodrug of the HIV-1 nucleotide reverse transcriptase (RT) inhibitor (NtRTI) tenofovir (TFV), with improved potency and drug delivery properties over the current prodrug, tenofovir disoproxil fumarate (TDF). TAF is currently in phase 3 clinical studies for the treatment of HIV-1 infection, in combination with other antiretroviral agents. Phase 1 and 2 studies have shown that TAF was associated with increased peripheral blood mononuclear cell (PBMC) drug loading and increased suppression of HIV-1 replication compared to treatment with TDF. In this study, selection of in vitro resistance to both TAF and the parent compound, TFV, led to the emergence of HIV-1 with the K65R amino acid substitution in RT with 6.5-fold-reduced susceptibility to TAF. Although TAF is more potent than TFV in vitro, the antiviral susceptibilities to TAF and TFV of a large panel of nucleoside/nucleotide RT inhibitor (NRTI)-resistant mutants were highly correlated (R(2) = 0.97), indicating that the two compounds have virtually the same resistance profile when assessed as fold change from the wild type. TAF showed full antiviral activity in PBMCs against primary HIV-1 isolates with protease inhibitor, nonnucleoside RT inhibitor (NNRTI), or integrase strand transfer inhibitor resistance but reduced activity against isolates with extensive NRTI resistance amino acid substitutions. However, the increased cell loading of TFV with TAF versus TDF observed in vivo suggests that TAF may retain activity against TDF-resistant mutant viruses. PMID:26149983

  13. Diversity of in-vivo assembled HIV-1 capsids

    NASA Astrophysics Data System (ADS)

    Lee, Se Il; Nguyen, Toan

    2008-03-01

    Understanding the capsid assembly process of Human Immunodeficiency Virus (HIV), the causative agent of Acute Immuno Deficiency Syndrom (AIDS), is very important because of recent intense interest in capsid-oriented viral therapy. The unique conical shapes of mature HIV-1 capsid have drawn significant interests in the biological community and started to attract attention from the physics community. Previous studies showed that in a free assembly process, the HIV-1 conical shape is not thermodynamically stable. However, if the volume of the capsid is constrained during assembly and the capsid protein shell has high spontaneous curvature, the conical shape is stable. In this work, we focus on in-vivo HIV-1 capsid assembly. For this case, the viral envelope membrane present during assembly imposes constraint on the length of the capsid. We use an elastic continuum shell theory to approximate the energies of various HIV-1 capsid shapes (spherical, cylindrical and conical). We show that for certain range of viral membrane diameter, the conical and cylindrical shapes are both thermodynamically stable. This result is supported by experimental observation that in-vivo assembled HIV-1 capsids are very heterogeneous in shapes and sizes. Numerical calculation is also performed to improve theoretical approximation.

  14. Inhibitors of HIV-1 replication that inhibit HIV integrase.

    PubMed Central

    Robinson, W E; Reinecke, M G; Abdel-Malek, S; Jia, Q; Chow, S A

    1996-01-01

    HIV-1 replication depends on the viral enzyme integrase that mediates integration of a DNA copy of the virus into the host cell genome. This enzyme represents a novel target to which antiviral agents might be directed. Three compounds, 3,5-dicaffeoylquinic acid, 1-methoxyoxalyl-3,5-dicaffeoylquinic acid, and L-chicoric acid, inhibit HIV-1 integrase in biochemical assays at concentrations ranging from 0.06-0.66 microgram/ml; furthermore, these compounds inhibit HIV-1 replication in tissue culture at 1-4 microgram/ml. The toxic concentrations of these compounds are fully 100-fold greater than their antiviral concentrations. These compounds represent a potentially important new class of antiviral agents that may contribute to our understanding of the molecular mechanisms of viral integration. Thus, the dicaffeoylquinic acids are promising leads to new anti-HIV therapeutics and offer a significant advance in the search for new HIV enzyme targets as they are both specific for HIV-1 integrase and active against HIV-1 in tissue culture. Images Fig. 3 PMID:8692814

  15. HIV-1 subtype B: Traces of a pandemic.

    PubMed

    Junqueira, Dennis Maletich; Almeida, Sabrina Esteves de Matos

    2016-08-01

    Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration. After localized dispersion, the virus was brought to the United States of America via homosexual/bisexual contact around 1969. Inside USA, the incidence of HIV-1B infection increased exponentially and it became established in the population, affecting not only homosexual individuals but also heterosexual individuals and injecting drug users. Soon after, the virus was disseminated and became established in other regions, including Europe, Asia, Latin America, and Australia. Recent studies suggest that, in addition to this pandemic clade, several lineages have emerged from Haiti and reached other Caribbean and Latin American countries via short-distance dissemination. Different subtype B genetic variants have also been detected in these epidemics. Four genetic variants have been described to date: subtype B', which mainly circulates in Thailand and other Asian countries; a specific variant mainly found in Trinidad and Tobago; the GPGS variant, which is primarily detected in Korea; and the GWGR variant, which is mainly detected in Brazil. This paper reviews the evolution of HIV-1B and its impact on the human population.

  16. HIV-1 functional cure: will the dream come true?

    PubMed

    Liu, Chao; Ma, Xiancai; Liu, Bingfeng; Chen, Cancan; Zhang, Hui

    2015-01-01

    The reservoir of human immunodeficiency virus type 1 (HIV-1), a long-lived pool of latently infected cells harboring replication-competent viruses, is the major obstacle to curing acquired immune deficiency syndrome (AIDS). Although the combination antiretroviral therapy (cART) can successfully suppress HIV-1 viremia and significantly delay the progression of the disease, it cannot eliminate the viral reservoir and the patient must continue to take anti-viral medicines for life. Currently, the appearance of the 'Berlin patient', the 'Boston patients', and the 'Mississippi baby' have inspired many therapeutic strategies for HIV-1 aimed at curing efforts. However, the specific eradication of viral latency and the recovery and optimization of the HIV-1-specific immune surveillance are major challenges to achieving such a cure. Here, we summarize recent studies addressing the mechanisms underlying the viral latency and define two categories of viral reservoir: 'shallow' and 'deep'. We also present the current strategies and recent advances in the development of a functional cure for HIV-1, focusing on full/partial replacement of the immune system, 'shock and kill', and 'permanent silencing' approaches. PMID:26588898

  17. HIV-1 subtype B: Traces of a pandemic.

    PubMed

    Junqueira, Dennis Maletich; Almeida, Sabrina Esteves de Matos

    2016-08-01

    Human migration is a major process that shaped the origin and dissemination of HIV. Within HIV-1, subtype B (HIV-1B) is the most disseminated variant and it is assumed to be the causative agent in approximately 11% of all cases of HIV worldwide. Phylogenetic studies have revealed that HIV-1B emerged in Kinshasa (Africa) and was introduced into the Caribbean region via Haiti in or around 1966 by human migration. After localized dispersion, the virus was brought to the United States of America via homosexual/bisexual contact around 1969. Inside USA, the incidence of HIV-1B infection increased exponentially and it became established in the population, affecting not only homosexual individuals but also heterosexual individuals and injecting drug users. Soon after, the virus was disseminated and became established in other regions, including Europe, Asia, Latin America, and Australia. Recent studies suggest that, in addition to this pandemic clade, several lineages have emerged from Haiti and reached other Caribbean and Latin American countries via short-distance dissemination. Different subtype B genetic variants have also been detected in these epidemics. Four genetic variants have been described to date: subtype B', which mainly circulates in Thailand and other Asian countries; a specific variant mainly found in Trinidad and Tobago; the GPGS variant, which is primarily detected in Korea; and the GWGR variant, which is mainly detected in Brazil. This paper reviews the evolution of HIV-1B and its impact on the human population. PMID:27228177

  18. Ketone bodies protection against HIV-1 Tat-induced neurotoxicity

    PubMed Central

    Hui, Liang; Chen, Xuesong; Bhatt, Dhaval; Geiger, Nicholas H.; Rosenberger, Thad A.; Haughey, Norman J.; Masino, Susan A.; Geiger, Jonathan D.

    2012-01-01

    HIV-1 associated neurocognitive disorder (HAND) is a syndrome that ranges clinically from subtle neuropsychological impairments to profoundly disabling HIV-associated dementia. Not only is the pathogenesis of HAND unclear, but also effective treatments are unavailable. The HIV-1 transactivator of transcription protein (HIV-1 Tat) is strongly implicated in the pathogenesis of HAND, in part, because of its well-characterized ability to directly excite neurons and cause neurotoxicity. Consistent with previous findings from others, we demonstrate here that HIV-1 Tat induced neurotoxicity, increased intracellular calcium, and disrupted a variety of mitochondria functions, such as reducing mitochondrial membrane potential, increasing levels of reactive oxygen species, and decreasing bioenergetic efficiency. Of therapeutic importance, we show that treatment of cultured neurons with ketone bodies normalized HIV-1 Tat induced changes in levels of intracellular calcium, mitochondrial function, and neuronal cell death. Ketone bodies are normally produced in the body and serve as alternative energy substrates in tissues including brain and can cross the blood-brain barrier. Ketogenic strategies have been used clinically for treatment of neurological disorders and our current results suggest that similar strategies may also provide clinical benefits in the treatment of HAND. PMID:22524563

  19. Antimalarial activity of HIV-1 protease inhibitor in chromone series.

    PubMed

    Lerdsirisuk, Pradith; Maicheen, Chirattikan; Ungwitayatorn, Jiraporn

    2014-12-01

    Increasing parasite resistance to nearly all available antimalarial drugs becomes a serious problem to human health and necessitates the need to continue the search for new effective drugs. Recent studies have shown that clinically utilized HIV-1 protease (HIV-1 PR) inhibitors can inhibit the in vitro and in vivo growth of Plasmodium falciparum. In this study, a series of chromone derivatives possessing HIV-1 PR inhibitory activity has been tested for antimalarial activity against P. falciparum (K1 multi-drug resistant strain). Chromone 15, the potent HIV-1 PR inhibitor (IC50=0.65μM), was found to be the most potent antimalarial compound with IC50=0.95μM while primaquine and tafenoquine showed IC50=2.41 and 1.95μM, respectively. Molecular docking study of chromone compounds against plasmepsin II, an aspartic protease enzyme important in hemoglobin degradation, revealed that chromone 15 exhibited the higher binding affinity (binding energy=-13.24kcal/mol) than the known PM II inhibitors. Thus, HIV-1 PR inhibitor in chromone series has the potential to be a new class of antimalarial agent. PMID:25462990

  20. [Advances in the Immunogenic Design of HIV-1 Vaccine].

    PubMed

    Zhang, Xiaohong; Wang, Tao; Yu, Xiaofang

    2016-01-01

    A safe and effective vaccine against the human immunodeficiency virus type 1 (HIV-1) is expected to have a considerable impact on elimination of acquired immune deficiency syndrome. Despite decades of effort, an effective vaccine against HIV-1 remains elusive. In recent years, the Thai HIV Vaccine Efficacy Trial (known as RV144) showed a reduction in HIV-1 acquisition by 31%, but this agent could not delay disease progression in vaccinated individuals. Clinical analyses of experimental data and experiments in vitro have revealed two main types of immunogen design: induction of broad-spectrum neutralizing antibody (bNAb) and cytotoxic T lymphocyte (CTL) responses. bNAb can prevent or reduce acquisition of infection, and its main immunogens are virus-like particles, natural envelope trimers and stable bNAb epitopes. An effective CTL response can slow-down viral infection, and its main immunogens are "mosaic" vaccines, "conserved immunogens", and the "fitness landscape" of HIV-1 proteins. This review summarizes the strategies as well as progress in the design and testing of HIV-1 immunogens to elicit bNAb and CTL responses. PMID:27295889

  1. The triple threat of HIV-1 protease inhibitors.

    PubMed

    Potempa, Marc; Lee, Sook-Kyung; Wolfenden, Richard; Swanstrom, Ronald

    2015-01-01

    Newly released human immunodeficiency virus type 1 (HIV-1) particles obligatorily undergo a maturation process to become infectious. The HIV-1 protease (PR) initiates this step, catalyzing the cleavage of the Gag and Gag-Pro-Pol structural polyproteins. Proper organization of the mature virus core requires that cleavage of these polyprotein substrates proceeds in a highly regulated, specific series of events. The vital role the HIV-1 PR plays in the viral life cycle has made it an extremely attractive target for inhibition and has accordingly fostered the development of a number of highly potent substrate-analog inhibitors. Though the PR inhibitors (PIs) inhibit only the HIV-1 PR, their effects manifest at multiple different stages in the life cycle due to the critical importance of the PR in preparing the virus for these subsequent events. Effectively, PIs masquerade as entry inhibitors, reverse transcription inhibitors, and potentially even inhibitors of post-reverse transcription steps. In this chapter, we review the triple threat of PIs: the intermolecular cooperativity in the form of a cooperative dose-response for inhibition in which the apparent potency increases with increasing inhibition; the pleiotropic effects of HIV-1 PR inhibition on entry, reverse transcription, and post-reverse transcription steps; and their potency as transition state analogs that have the potential for further improvement that could lead to an inability of the virus to evolve resistance in the context of single drug therapy. PMID:25778681

  2. Antiretroviral Therapy and Central Nervous System HIV-1 Infection

    PubMed Central

    Price, Richard W.; Spudich, Serena

    2008-01-01

    Central nervous system (CNS) HIV-1 infection begins during primary viremia and continues throughout the course of untreated systemic infection. While frequently accompanied by local inflammatory reactions detectable in cerebrospinal fluid (CSF), CNS HIV-1 infection is not usually clinically apparent. In a minority of patients, CNS HIV-1 infection evolves late in the course of systemic infection into encephalitis, which compromises brain function and presents clinically as AIDS dementia complex (ADC). Combination highly active antiretroviral therapy (HAART) has had a major impact on all aspects of HIV-1 CNS infection and disease. In those with asymptomatic infection, HAART usually effectively suppresses CSF HIV-1 and markedly reduces the incidence of symptomatic ADC. In those presenting with ADC, HAART characteristically prevents neurological progression and leads to variable, and at times substantial, recovery. Treatment has similarly reduced CNS opportunistic infections. With better control of these severe disorders, attention has turned to the possible consequences of chronic silent infection, and the issue of whether indolent, low-grade brain injury might require earlier treatment intervention. PMID:18447615

  3. A small molecule HIV-1 inhibitor that targets the HIV-1 envelope and inhibits CD4 receptor binding

    PubMed Central

    Lin, Pin-Fang; Blair, Wade; Wang, Tao; Spicer, Timothy; Guo, Qi; Zhou, Nannan; Gong, Yi-Fei; Wang, H.-G. Heidi; Rose, Ronald; Yamanaka, Gregory; Robinson, Brett; Li, Chang-Ben; Fridell, Robert; Deminie, Carol; Demers, Gwendeline; Yang, Zheng; Zadjura, Lisa; Meanwell, Nicholas; Colonno, Richard

    2003-01-01

    BMS-378806 is a recently discovered small molecule HIV-1 inhibitor that blocks viral entrance to cells. The compound exhibits potent inhibitory activity against a panel of R5-(virus using the CCR5 coreceptor), X4-(virus using the CXCR4 coreceptor), and R5/X4 HIV-1 laboratory and clinical isolates of the B subtype (median EC50 of 0.04 μM) in culture assays. BMS-378806 is selective for HIV-1 and inactive against HIV-2, SIV and a panel of other viruses, and exhibits no significant cytotoxicity in the 14 cell types tested (concentration for 50% reduction of cell growth, >225 μM). Mechanism of action studies demonstrated that BMS-378806 binds to gp120 and inhibits the interactions of the HIV-1 envelope protein to cellular CD4 receptors. Further confirmation that BMS-378806 targets the envelope in infected cells was obtained through the isolation of resistant variants and the mapping of resistance substitutions to the HIV-1 envelope. In particular, two substitutions, M426L and M475I, are situated in the CD4 binding pocket of gp120. Recombinant HIV-1 carrying these two substitutions demonstrated significantly reduced susceptibility to compound inhibition. BMS-378806 displays many favorable pharmacological traits, such as low protein binding, minimal human serum effect on anti-HIV-1 potency, good oral bioavailability in animal species, and a clean safety profile in initial animal toxicology studies. Together, the data show that BMS-378806 is a representative of a new class of HIV inhibitors that has the potential to become a valued addition to our current armamentarium of antiretroviral drugs. PMID:12930892

  4. Glutamic Acid Residues in HIV-1 p6 Regulate Virus Budding and Membrane Association of Gag

    PubMed Central

    Friedrich, Melanie; Setz, Christian; Hahn, Friedrich; Matthaei, Alina; Fraedrich, Kirsten; Rauch, Pia; Henklein, Petra; Traxdorf, Maximilian; Fossen, Torgils; Schubert, Ulrich

    2016-01-01

    The HIV-1 Gag p6 protein regulates the final abscission step of nascent virions from the cell membrane by the action of its two late (l-) domains, which recruit Tsg101 and ALIX, components of the ESCRT system. Even though p6 consists of only 52 amino acids, it is encoded by one of the most polymorphic regions of the HIV-1 gag gene and undergoes various posttranslational modifications including sumoylation, ubiquitination, and phosphorylation. In addition, it mediates the incorporation of the HIV-1 accessory protein Vpr into budding virions. Despite its small size, p6 exhibits an unusually high charge density. In this study, we show that mutation of the conserved glutamic acids within p6 increases the membrane association of Pr55 Gag followed by enhanced polyubiquitination and MHC-I antigen presentation of Gag-derived epitopes, possibly due to prolonged exposure to membrane bound E3 ligases. The replication capacity of the total glutamic acid mutant E0A was almost completely impaired, which was accompanied by defective virus release that could not be rescued by ALIX overexpression. Altogether, our data indicate that the glutamic acids within p6 contribute to the late steps of viral replication and may contribute to the interaction of Gag with the plasma membrane. PMID:27120610

  5. The Clathrin Adaptor Complex AP-1 Binds HIV-1 and MLV Gag and Facilitates Their Budding

    PubMed Central

    Camus, Grégory; Segura-Morales, Carolina; Molle, Dorothee; Lopez-Vergès, Sandra; Begon-Pescia, Christina; Cazevieille, Chantal; Schu, Peter; Bertrand, Edouard

    2007-01-01

    Retroviral assembly is driven by Gag, and nascent viral particles escape cells by recruiting the machinery that forms intralumenal vesicles of multivesicular bodies. In this study, we show that the clathrin adaptor complex AP-1 is involved in retroviral release. The absence of AP-1μ obtained by genetic knock-out or by RNA interference reduces budding of murine leukemia virus (MLV) and HIV-1, leading to a delay of viral propagation in cell culture. In contrast, overexpression of AP-1μ enhances release of HIV-1 Gag. We show that the AP-1 complex facilitates retroviral budding through a direct interaction between the matrix and AP-1μ. Less MLV Gag is found associated with late endosomes in cells lacking AP-1, and our results suggest that AP-1 and AP-3 could function on the same pathway that leads to Gag release. In addition, we find that AP-1 interacts with Tsg101 and Nedd4.1, two cellular proteins known to be involved in HIV-1 and MLV budding. We propose that AP-1 promotes Gag release by transporting it to intracellular sites of active budding, and/or by facilitating its interactions with other cellular partners. PMID:17538020

  6. Biophysical characterization of V3-lipopeptide liposomes influencing HIV-1 infectivity

    SciTech Connect

    Rizos, Apostolos K. . E-mail: Rizos@iesl.forth.gr; Baritaki, Stavroula; Tsikalas, Ioannis; Doetschman, David C.; Spandidos, Demetrios A.; Krambovitis, Elias; E-mail: krambo@imbb.forth.gr

    2007-04-20

    The V3-loop of the HIV-1 gp120 alters host cell immune function and modulates infectivity. We investigated biophysical parameters of liposome constructs with embedded lipopeptides from the principle neutralizing domain of the V3-loop and their influence on viral infectivity. Dynamic light scattering measurements showed liposome supramolecular structures with hydrodynamic radius of the order of 900 and 1300 nm for plain and V3-lipopeptide liposomes. Electron paramagnetic resonance measurements showed almost identical local microenvironment. The difference in liposome hydrodynamic radius was attributed to the fluctuating ionic environment of the V3-lipopeptide liposomes. In vitro HIV-1 infectivity assays showed that plain liposomes reduced virus production in all cell cultures, probably due to the hydrophobic nature of the aggregates. Liposomes carrying V3-lipopeptides with different cationic potentials restored and even enhanced infectivity (p < 0.05). These results highlight the need for elucidation of the involvement of lipid bilayers as dynamic components in supramolecular structures and in HIV-1 fusion mechanisms.

  7. The cross-talk of HIV-1 Tat and methamphetamine in HIV-associated neurocognitive disorders

    PubMed Central

    Mediouni, Sonia; Garibaldi Marcondes, Maria Cecilia; Miller, Courtney; McLaughlin, Jay P.; Valente, Susana T.

    2015-01-01

    Antiretroviral therapy has dramatically improved the lives of human immunodeficiency virus 1 (HIV-1) infected individuals. Nonetheless, HIV-associated neurocognitive disorders (HAND), which range from undetectable neurocognitive impairments to severe dementia, still affect approximately 50% of the infected population, hampering their quality of life. The persistence of HAND is promoted by several factors, including longer life expectancies, the residual levels of virus in the central nervous system (CNS) and the continued presence of HIV-1 regulatory proteins such as the transactivator of transcription (Tat) in the brain. Tat is a secreted viral protein that crosses the blood–brain barrier into the CNS, where it has the ability to directly act on neurons and non-neuronal cells alike. These actions result in the release of soluble factors involved in inflammation, oxidative stress and excitotoxicity, ultimately resulting in neuronal damage. The percentage of methamphetamine (MA) abusers is high among the HIV-1-positive population compared to the general population. On the other hand, MA abuse is correlated with increased viral replication, enhanced Tat-mediated neurotoxicity and neurocognitive impairments. Although several strategies have been investigated to reduce HAND and MA use, no clinically approved treatment is currently available. Here, we review the latest findings of the effects of Tat and MA in HAND and discuss a few promising potential therapeutic developments. PMID:26557111

  8. Novel RNA Duplex Locks HIV-1 in a Latent State via Chromatin-mediated Transcriptional Silencing

    PubMed Central

    Ahlenstiel, Chantelle; Mendez, Catalina; Lim, Steven T H; Marks, Katherine; Turville, Stuart; Cooper, David A; Kelleher, Anthony D; Suzuki, Kazuo

    2015-01-01

    Transcriptional gene silencing (TGS) of mammalian genes can be induced by short interfering RNA (siRNA) targeting promoter regions. We previously reported potent TGS of HIV-1 by siRNA (PromA), which targets tandem NF-κB motifs within the viral 5′LTR. In this study, we screened a siRNA panel with the aim of identifying novel 5′LTR targets, to provide multiplexing potential with enhanced viral silencing and application toward developing alternate therapeutic strategies. Systematic examination identified a novel siRNA target, si143, confirmed to induce TGS as the silencing mechanism. TGS was prolonged with virus suppression >12 days, despite a limited ability to induce post- TGS. Epigenetic changes associated with silencing were suggested by partial reversal by histone deacetylase inhibitors and confirmed by chromatin immunoprecipitation analyses, which showed induction of H3K27me3 and H3K9me3, reduction in H3K9Ac, and recruitment of argonaute-1, all characteristic marks of heterochromatin and TGS. Together, these epigenetic changes mimic those associated with HIV-1 latency. Further, robust resistance to reactivation was observed in the J-Lat 9.2 cell latency model, when transduced with shPromA and/or sh143. These data support si/shRNA-mediated TGS approaches to HIV-1 and provide alternate targets to pursue a functional cure, whereby the viral reservoir is locked in latency following antiretroviral therapy cessation. PMID:26506039

  9. Design, Synthesis, Biological and Structural Evaluations of Novel HIV-1 Protease Inhibitors to Combat Drug Resistance

    PubMed Central

    Parai, Maloy Kumar; Huggins, David J.; Cao, Hong; Nalam, Madhavi N. L.; Ali, Akbar; Schiffer, Celia A.; Tidor, Bruce; Rana, Tariq M.

    2012-01-01

    A series of new HIV-1 protease inhibitors (PIs) were designed using a general strategy that combines computational structure-based design with substrate-envelope constraints. The PIs incorporate various alcohol-derived P2 carbamates with acyclic and cyclic heteroatomic functionalities into the (R)-hydroxyethylamine isostere. Most of the new PIs show potent binding affinities against wild-type HIV-1 protease and three multidrug resistant (MDR) variants, in particular inhibitors containing 2,2-dichloroacetamide, pyrrolidinone, imidazolidinone, and oxazolidinone moieties at P2 are the most potent with Ki values in the picomolar range. Several new PIs exhibit nanomolar antiviral potencies against patient-derived wild-type viruses from HIV-1 clades A, B, and C and two MDR variants. Crystal structure analyses of four potent inhibitors revealed that carbonyl groups of the new P2 moieties promote extensive hydrogen bond interactions with the invariant Asp-29 residue of the protease. These structure-activity relationship findings can be utilized to design new PIs with enhanced enzyme inhibitory and antiviral potencies. PMID:22708897

  10. Identification of a differentially expressed mRNA in axenic Leishmania panamensis amastigotes.

    PubMed

    Gutiérrez, J A; Puentes, F; Moreno, A; Patarroyo, M E; Murillo, L A

    2001-08-01

    Differential display technique was applied in order to identify transcripts which are present in axenic amastigotes but not in promastigotes of the Leishmania panamensis parasites. One of them was cloned and the sequence reveals an open reading frame of 364 amino acids (approximately 40 kDa). The deduced protein is homologous to the serine/threonine protein kinases and specially to the mitogen activates protein kinases from eukaryotic species. Southern blot analysis suggest that this transcript, named lpmkh, is present in the genome of the parasite as a single copy gene. These results could imply that lpmkh could be involved in the differentiation process or the preservation of amastigotes in axenic conditions. PMID:11562712

  11. Macrophages and lymphocytes differentially modulate the ability of RANTES to inhibit HIV-1 infection.

    PubMed

    Gross, Eleanore; Amella, Carol A; Pompucci, Lorena; Franchin, Giovanni; Sherry, Barbara; Schmidtmayerova, Helena

    2003-11-01

    The beta-chemokines MIP-1alpha, MIP-1beta, and RANTES inhibit HIV-1 infection of CD4+ T cells by inhibiting interactions between the virus and CCR5 receptors. However, while beta-chemokine-mediated inhibition of HIV-1 infection of primary lymphocytes is well documented, conflicting results have been obtained using primary macrophages as the virus target. Here, we show that the beta-chemokine RANTES inhibits virus entry into both cellular targets of the virus, lymphocytes and macrophages. However, while virus entry is inhibited at the moment of infection in both cell types, the amount of virus progeny is lowered only in lymphocytes. In macrophages, early-entry restriction is lost during long-term cultivation, and the amount of virus produced by RANTES-treated macrophages is similar to the untreated cultures, suggesting an enhanced virus replication. We further show that at least two distinct cellular responses to RANTES treatment in primary lymphocytes and macrophages contribute to this phenomenon. In lymphocytes, exposure to RANTES significantly increases the pool of inhibitory beta-chemokines through intracellular signals that result in increased production of MIP-1alpha and MIP-1beta, thereby amplifying the antiviral effects of RANTES. In macrophages this amplification step does not occur. In fact, RANTES added to the macrophages is efficiently cleared from the culture, without inducing synthesis of beta-chemokines. Our results demonstrate dichotomous effects of RANTES on HIV-1 entry at the moment of infection, and on production and spread of virus progeny in primary macrophages. Since macrophages serve as a reservoir of HIV-1, this may contribute to the failure of endogenous chemokines to successfully eradicate the virus.

  12. HIV-1 Reservoir Dynamics after Vaccination and Antiretroviral Therapy Interruption Are Associated with Dendritic Cell Vaccine-Induced T Cell Responses

    PubMed Central

    Andrés, Cristina; Plana, Montserrat; Guardo, Alberto C.; Alvarez-Fernández, Carmen; Climent, Nuria; Gallart, Teresa; León, Agathe; Clotet, Bonaventura; Autran, Brigitte; Chomont, Nicolas; Gatell, Josep M.; Sánchez-Palomino, Sonsoles

    2015-01-01

    . The development of therapeutic vaccines aimed at enhancing immune-mediated clearance of virus-producing cells is of high priority. Few therapeutic vaccine clinical trials have investigated the role of therapeutic vaccines as a strategy to safely eliminate or control viral reservoirs. We recently reported that a dendritic cell-based therapeutic vaccine was able to significantly decrease the viral set point in vaccinated patients, with a concomitant increase in HIV-1-specific T cell responses. The HIV-1-specific T cell immune responses elicited by this therapeutic dendritic cell vaccine drove changes in the viral reservoir after vaccinations and significantly delayed the replenishment of integrated HIV-1 DNA after cART interruption. These data help in understanding how an immunization could shift the virus-host balance and are instrumental for better design of strategies to reach a functional cure of HIV-1 infection. PMID:26109727

  13. The Role of Interleukin-23 in the Early Development of Emphysema in HIV1+ Smokers

    PubMed Central

    Barjaktarevic, Igor Z.; Crystal, Ronald G.

    2016-01-01

    Rationale. Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1+ smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1+ smokers contains increased levels of inflammatory cytokines compared to HIV1− smokers, we hypothesized that upregulation of lung cytokines in HIV1+ smokers may be functionally related to increased MMP-9 expression. Methods. Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1− healthy nonsmokers, HIV1− healthy smokers, HIV1− smokers with low diffusing capacity (DLCO), HIV1+ nonsmokers, and HIV1+ smokers with low DLCO. Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1− smokers with low DLCO and HIV1+ smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1+ individuals, with greater expression in AM of HIV1+ smokers with low DLCO. Infection with HIV1 in vitro induced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte cocultures in vitro induced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9. Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1+ smokers and suggests that Th17 related inflammation may play a role. PMID:27446965

  14. The Role of Interleukin-23 in the Early Development of Emphysema in HIV1(+) Smokers.

    PubMed

    Barjaktarevic, Igor Z; Crystal, Ronald G; Kaner, Robert J

    2016-01-01

    Rationale. Matrix metalloproteinase-9 (MMP-9) expression is upregulated in alveolar macrophages (AM) of HIV1(+) smokers who develop emphysema. Knowing that lung epithelial lining fluid (ELF) of HIV1(+) smokers contains increased levels of inflammatory cytokines compared to HIV1(-) smokers, we hypothesized that upregulation of lung cytokines in HIV1(+) smokers may be functionally related to increased MMP-9 expression. Methods. Cytokine arrays evaluated cytokine protein levels in ELF obtained from 5 groups of individuals: HIV1(-) healthy nonsmokers, HIV1(-) healthy smokers, HIV1(-) smokers with low diffusing capacity (DLCO), HIV1(+) nonsmokers, and HIV1(+) smokers with low DLCO. Results. Increased levels of the Th17 related cytokine IL-23 were found in HIV1(-) smokers with low DLCO and HIV1(+) smokers and nonsmokers. Relative IL-23 gene expression was increased in AM of HIV1(+) individuals, with greater expression in AM of HIV1(+) smokers with low DLCO. Infection with HIV1 in vitro induced IL-23 expression in normal AM. IL-23 stimulation of AM/lymphocyte cocultures in vitro induced upregulation of MMP-9. Lung T lymphocytes express receptor IL-23R and interact with AM in order to upregulate MMP-9. Conclusion. This mechanism may contribute to the increased tissue destruction in the lungs of HIV1(+) smokers and suggests that Th17 related inflammation may play a role. PMID:27446965

  15. Biochemical and biological characterization of the protective Leishmania pifanoi amastigote antigen P-8.

    PubMed

    Colmenares, M; Tiemeyer, M; Kima, P; McMahon-Pratt, D

    2001-11-01

    The Leishmania pifanoi amastigote antigen P-8 has been previously shown to induce protective immunity in a murine model of cutaneous leishmaniasis (L. Soong, S. M. Duboise, P. Kima, and D. McMahon-Pratt, Infect. Immun. 63:3559-3566, 1995). As this antigen is of interest for further vaccine studies, the biochemical characterization of P-8 was undertaken. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Western-blot analysis, and gel filtration chromatography revealed that P-8 antigen consisted of two proteoglycolipid complexes. The P-8 epitope is associated with the L. pifanoi amastigote-specific glycolipid components found in the two complexes. The P-8 complex 1 (P-8c1) consists of a 56-kDa serine metalloproteinase, apolipoprotein E (derived from fetal bovine serum), and amastigote-specific glycolipids. The P-8 complex 2 (P-8c2) consists of a 31-kDa cysteine proteinase associated with amastigote glycolipids. Biochemical analyses suggest that the P-8 antigenic glycolipids may be distinct from previously described Leishmania glycolipids (glycosylinositol-phospholipids and sphingoglycolipids). Protective immunity studies revealed that P-8c1 (serine metalloproteinase-glycolipid complex) confers comparable protection against infection as immunopurified P-8. The isolated P-8c2 (cysteine proteinase-glycolipid complex) does not provide significant protection, nor does stimulation with P-8c2 result in significant T-cell activation in P-8- or P-8c2-vaccinated mice. Consequently, the P-8c1 complex appears to be the immunodominant component of P-8.

  16. Transgenic, Fluorescent Leishmania mexicana Allow Direct Analysis of the Proteome of Intracellular Amastigotes*S⃞

    PubMed Central

    Paape, Daniel; Lippuner, Christoph; Schmid, Monika; Ackermann, Renate; Barrios-Llerena, Martin E.; Zimny-Arndt, Ursula; Brinkmann, Volker; Arndt, Benjamin; Pleissner, Klaus Peter; Jungblut, Peter R.; Aebischer, Toni

    2008-01-01

    Investigating the proteome of intracellular pathogens is often hampered by inadequate methodologies to purify the pathogen free of host cell material. This has also precluded direct proteome analysis of the intracellular, amastigote form of Leishmania spp., protozoan parasites that cause a spectrum of diseases that affect some 12 million patients worldwide. Here a method is presented that combines classic, isopycnic density centrifugation with fluorescent particle sorting for purification by exploiting transgenic, fluorescent parasites to allow direct proteome analysis of the purified organisms. By this approach the proteome of intracellular Leishmania mexicana amastigotes was compared with that of extracellular promastigotes that are transmitted by insect vectors. In total, 509 different proteins were identified by mass spectrometry and database search. This number corresponds to ∼6% of gene products predicted from the reference genome of Leishmania major. Intracellular amastigotes synthesized significantly more proteins with basic pI and showed a greater abundance of enzymes of fatty acid catabolism, which may reflect their living in acidic habitats and metabolic adaptation to nutrient availability, respectively. Bioinformatics analyses of the genes corresponding to the protein data sets produced clear evidence for skewed codon usage and translational bias in these organisms. Moreover analysis of the subset of genes whose products were more abundant in amastigotes revealed characteristic sequence motifs in 3′-untranslated regions that have been linked to translational control elements. This suggests that proteome data sets may be used to identify regulatory elements in mRNAs. Last but not least, at 6% coverage the proteome identified all vaccine antigens tested to date. Thus, the present data set provides a valuable resource for selection of candidate vaccine antigens. PMID:18474515

  17. Genotype dependent QSAR for HIV-1 protease inhibition.

    PubMed

    Boutton, Carlo W; De Bondt, Hendrik L; De Jonge, Marc R

    2005-03-24

    The development of drug-resistant viruses limits the therapeutic success of anti-HIV therapies. Some of these genetic HIV-variants display complex mutational patterns in their pol gene that codes for protease and reverse transcriptase, the most investigated molecular targets for antiretroviral therapy. In this paper, we present a computational structure-based approach to predict the resistance of a HIV-1 protease strain to amprenavir by calculating the interaction energy of the drug with HIV-1 protease. By considering the interaction energy per residue, we can identify what residue mutations contribute to drug-resistance. This approach is presented here as a structure-based tool for the prediction of resistance of HIV-1 protease toward amprenavir, with a view to use the drug-protein interaction-energy pattern in a lead-optimization procedure for the discovery of new anti-HIV drugs. PMID:15771454

  18. Structural basis for membrane anchoring of HIV-1 envelope spike.

    PubMed

    Dev, Jyoti; Park, Donghyun; Fu, Qingshan; Chen, Jia; Ha, Heather Jiwon; Ghantous, Fadi; Herrmann, Tobias; Chang, Weiting; Liu, Zhijun; Frey, Gary; Seaman, Michael S; Chen, Bing; Chou, James J

    2016-07-01

    HIV-1 envelope spike (Env) is a type I membrane protein that mediates viral entry. We used nuclear magnetic resonance to determine an atomic structure of the transmembrane (TM) domain of HIV-1 Env reconstituted in bicelles that mimic a lipid bilayer. The TM forms a well-ordered trimer that protects a conserved membrane-embedded arginine. An amino-terminal coiled-coil and a carboxyl-terminal hydrophilic core stabilize the trimer. Individual mutations of conserved residues did not disrupt the TM trimer and minimally affected membrane fusion and infectivity. Major changes in the hydrophilic core, however, altered the antibody sensitivity of Env. These results show how a TM domain anchors, stabilizes, and modulates a viral envelope spike and suggest that its influence on Env conformation is an important consideration for HIV-1 immunogen design. PMID:27338706

  19. Immunological biomarkers predict HIV-1 viral rebound after treatment interruption

    PubMed Central

    Hurst, Jacob; Hoffmann, Matthias; Pace, Matthew; Williams, James P.; Thornhill, John; Hamlyn, Elizabeth; Meyerowitz, Jodi; Willberg, Chris; Koelsch, Kersten K.; Robinson, Nicola; Brown, Helen; Fisher, Martin; Kinloch, Sabine; Cooper, David A.; Schechter, Mauro; Tambussi, Giuseppe; Fidler, Sarah; Babiker, Abdel; Weber, Jonathan; Kelleher, Anthony D.; Phillips, Rodney E.; Frater, John

    2015-01-01

    Treatment of HIV-1 infection with antiretroviral therapy (ART) in the weeks following transmission may induce a state of ‘post-treatment control' (PTC) in some patients, in whom viraemia remains undetectable when ART is stopped. Explaining PTC could help our understanding of the processes that maintain viral persistence. Here we show that immunological biomarkers can predict time to viral rebound after stopping ART by analysing data from a randomized study of primary HIV-1 infection incorporating a treatment interruption (TI) after 48 weeks of ART (the SPARTAC trial). T-cell exhaustion markers PD-1, Tim-3 and Lag-3 measured prior to ART strongly predict time to the return of viraemia. These data indicate that T-cell exhaustion markers may identify those latently infected cells with a higher proclivity to viral transcription. Our results may open new avenues for understanding the mechanisms underlying PTC, and eventually HIV-1 eradication. PMID:26449164

  20. Immunological biomarkers predict HIV-1 viral rebound after treatment interruption.

    PubMed

    Hurst, Jacob; Hoffmann, Matthias; Pace, Matthew; Williams, James P; Thornhill, John; Hamlyn, Elizabeth; Meyerowitz, Jodi; Willberg, Chris; Koelsch, Kersten K; Robinson, Nicola; Brown, Helen; Fisher, Martin; Kinloch, Sabine; Cooper, David A; Schechter, Mauro; Tambussi, Giuseppe; Fidler, Sarah; Babiker, Abdel; Weber, Jonathan; Kelleher, Anthony D; Phillips, Rodney E; Frater, John

    2015-01-01

    Treatment of HIV-1 infection with antiretroviral therapy (ART) in the weeks following transmission may induce a state of 'post-treatment control' (PTC) in some patients, in whom viraemia remains undetectable when ART is stopped. Explaining PTC could help our understanding of the processes that maintain viral persistence. Here we show that immunological biomarkers can predict time to viral rebound after stopping ART by analysing data from a randomized study of primary HIV-1 infection incorporating a treatment interruption (TI) after 48 weeks of ART (the SPARTAC trial). T-cell exhaustion markers PD-1, Tim-3 and Lag-3 measured prior to ART strongly predict time to the return of viraemia. These data indicate that T-cell exhaustion markers may identify those latently infected cells with a higher proclivity to viral transcription. Our results may open new avenues for understanding the mechanisms underlying PTC, and eventually HIV-1 eradication.

  1. Lipids and Membrane Microdomains in HIV-1 Replication

    PubMed Central

    Waheed, Abdul A.; Freed, Eric O.

    2009-01-01

    Several critical steps in the replication cycle of human immunodeficiency virus type 1 (HIV-1) – entry, assembly and budding – are complex processes that take place at the plasma membrane of the host cell. A growing body of data indicates that these early and late steps in HIV-1 replication take place in specialized plasma membrane microdomains, and that many of the viral and cellular components required for entry, assembly, and budding are concentrated in these microdomains. In particular, a number of studies have shown that cholesterol- and sphingolipid-enriched microdomains known as lipid rafts play important roles in multiple steps in the virus replication cycle. In this review, we provide an overview of what is currently known about the involvement of lipids and membrane microdomains in HIV-1 replication. PMID:19383519

  2. HIV-1 and the immune response to TB

    PubMed Central

    Walker, Naomi F; Meintjes, Graeme; Wilkinson, Robert J

    2013-01-01

    TB causes 1.4 million deaths annually. HIV-1 infection is the strongest risk factor for TB. The characteristic immunological effect of HIV is on CD4 cell count. However, the risk of TB is elevated in HIV-1 infected individuals even in the first few years after HIV acquisition and also after CD4 cell counts are restored with antiretroviral therapy. In this review, we examine features of the immune response to TB and how this is affected by HIV-1 infection and vice versa. We discuss how the immunology of HIV–TB coinfection impacts on the clinical presentation and diagnosis of TB, and how antiretroviral therapy affects the immune response to TB, including the development of TB immune reconstitution inflammatory syndrome. We highlight important areas of uncertainty and future research needs. PMID:23653664

  3. Anti-HIV-1 protease- and HIV-1 integrase activities of Thai medicinal plants known as Hua-Khao-Yen.

    PubMed

    Tewtrakul, Supinya; Itharat, Arunporn; Rattanasuwan, Pranee

    2006-04-21

    Ethanolic- and water extracts from five species of Thai medicinal plants known as Hua-Khao-Yen were tested for their inhibitory effects against HIV-1 protease (HIV-PR) and HIV-1 integrase (HIV-1 IN). The result revealed that the ethanolic (EtOH) extract of Smilax corbularia exhibited anti-HIV-1 IN activity with an IC50 value of 1.9 microg/ml, followed by the water extract of Dioscorea birmanica (IC50 = 4.5 microg/ml), the EtOH extract of Dioscorea birmanica (IC50 = 4.7 microg/ml), the water extract of Smilax corbularia (IC50 = 5.4 microg/ml), the EtOH extract of Smilax glabra (IC50 = 6.7 microg/ml) and the water extract of Smilax glabra (IC50 = 8.5 microg/ml). The extracts of Pygmaeopremna herbacea and Dioscorea membranacea were apparently inactive (IC50 > 100 microg/ml). Interestingly, only the EtOH extract of Dioscorea membranacea showed appreciable activity (IC50 = 48 microg/ml) against HIV-1 PR, while the other extracts possessed mild activity. This result strongly supported the basis for the use of Smilax corbularia and Dioscorea membranacea for AIDS treatment by Thai traditional doctors. PMID:16406414

  4. Selective elimination of HIV-1-infected cells by Env-directed, HIV-1-based virus-like particles

    SciTech Connect

    Peretti, Silvia; Schiavoni, Ilaria; Pugliese, Katherina; Federico, Maurizio . E-mail: federico@iss.it

    2006-02-05

    We recently showed that both replicating and resting cells cultivated with ganciclovir (GCV) were killed when challenged with vesicular stomatitis virus G glycoprotein pseudotyped HIV-1-based virus-like particles (VLPs) carrying the Nef7 (i.e., an HIV-1 Nef mutant incorporating in virions at high levels)/herpes simplex virus-1 thymidine kinase (HSV-TK) fusion product. On this basis, a novel anti-HIV therapeutic approach based on Nef7/TK VLPs expressing X4 or R5 HIV cell receptor complexes has been attempted. We here report that (CD4-CXCR4) and (CD4-CCR5) Nef7-based VLPs efficiently enter cells infected by X4- or R5-tropic HIV-1 strains, respectively. Importantly, the delivery of the VLP-associated Nef7/TK led to cell death upon GCV treatment. Of interest, VLPs were effective also against non-replicating, HIV-1-infected primary human monocyte-derived macrophages. HIV-targeted VLPs represent a promising candidate for the treatment of persistently HIV-1-infected cells that are part of virus reservoirs resistant to HAART therapies.

  5. 2´,3´-Dialdehyde of ATP, ADP, and adenosine inhibit HIV-1 reverse transcriptase and HIV-1 replication.

    PubMed

    Schachter, Julieta; Valadao, Ana Luiza Chaves; Aguiar, Renato Santana; Barreto-de-Souza, Victor; Rossi, Atila Duque; Arantes, Pablo Ricardo; Verli, Hugo; Quintana, Paula Gabriela; Heise, Norton; Tanuri, Amilcar; Bou-Habib, Dumith Chequer; Persechini, Pedro Muanis

    2014-01-01

    The 2´3´-dialdehyde of ATP or oxidized ATP (oATP) is a compound known for specifically making covalent bonds with the nucleotide-binding site of several ATP-binding enzymes and receptors. We investigated the effects of oATP and other oxidized purines on HIV-1 infection and we found that this compound inhibits HIV-1 and SIV infection by blocking early steps of virus replication. oATP, oxidized ADP (oADP), and oxidized Adenosine (oADO) impact the natural activity of endogenous reverse transcriptase enzyme (RT) in cell free virus particles and are able to inhibit viral replication in different cell types when added to the cell cultures either before or after infection. We used UFLC-UV to show that both oADO and oATP can be detected in the cell after being added in the extracellular medium. oATP also suppresses RT activity and replication of the HIV-1 resistant variants M184V and T215Y. We conclude that oATP, oADP and oADO display anti HIV-1 activity that is at in least in part due to inhibitory activity on HIV-1 RT.

  6. Extracellular amastigotes of Trypanosoma cruzi are potent inducers of phagocytosis in mammalian cells.

    PubMed

    Fernandes, Maria Cecilia; Flannery, Andrew R; Andrews, Norma; Mortara, Renato A

    2013-06-01

    The protozoan parasite Trypanosoma cruzi, the aetiological agent of Chagas' disease, has two infective life cycle stages, trypomastigotes and amastigotes. While trypomastigotes actively enter mammalian cells, highly infective extracellular amastigotes (type I T. cruzi) rely on actin-mediated uptake, which is generally inefficient in non-professional phagocytes. We found that extracellular amastigotes (EAs) of T. cruzi G strain (type I), but not Y strain (type II), were taken up 100-fold more efficiently than inert particles. Mammalian cell lines showed levels of parasite uptake comparable to macrophages, and extensive actin recruitment and polymerization was observed at the site of entry. EA uptake was not dependent on parasite-secreted molecules and required the same molecular machinery utilized by professional phagocytes during large particle phagocytosis. Transcriptional silencing of synaptotagmin VII and CD63 significantly inhibited EA internalization, demonstrating that delivery of supplemental lysosomal membrane to form the phagosome is involved in parasite uptake. Importantly, time-lapse live imaging using fluorescent reporters revealed phagosome-associated modulation of phosphoinositide metabolism during EA uptake that closely resembles what occurs during phagocytosis by macrophages. Collectively, our results demonstrate that T. cruzi EAs are potent inducers of phagocytosis in non-professional phagocytes, a process that may facilitate parasite persistence in infected hosts.

  7. A New Approach to Produce HIV-1 Envelope Trimers

    PubMed Central

    AlSalmi, Wadad; Mahalingam, Marthandan; Ananthaswamy, Neeti; Hamlin, Christopher; Flores, Dalia; Gao, Guofen; Rao, Venigalla B.

    2015-01-01

    The trimeric envelope spike of HIV-1 mediates virus entry into human cells. The exposed part of the trimer, gp140, consists of two noncovalently associated subunits, gp120 and gp41 ectodomain. A recombinant vaccine that mimics the native trimer might elicit entry-blocking antibodies and prevent virus infection. However, preparation of authentic HIV-1 trimers has been challenging. Recently, an affinity column containing the broadly neutralizing antibody 2G12 has been used to capture recombinant gp140 and prepare trimers from clade A BG505 that naturally produces stable trimers. However, this antibody-based approach may not be as effective for the diverse HIV-1 strains with different epitope signatures. Here, we report a new and simple approach to produce HIV-1 envelope trimers. The C terminus of gp140 was attached to Strep-tag II with a long linker separating the tag from the massive trimer base and glycan shield. This allowed capture of nearly homogeneous gp140 directly from the culture medium. Cleaved, uncleaved, and fully or partially glycosylated trimers from different clade viruses were produced. Extensive biochemical characterizations showed that cleavage of gp140 was not essential for trimerization, but it triggered a conformational change that channels trimers into correct glycosylation pathways, generating compact three-blade propeller-shaped trimers. Uncleaved trimers entered aberrant pathways, resulting in hyperglycosylation, nonspecific cross-linking, and conformational heterogeneity. Even the cleaved trimers showed microheterogeneity in gp41 glycosylation. These studies established a broadly applicable HIV-1 trimer production system as well as generating new insights into their assembly and maturation that collectively bear on the HIV-1 vaccine design. PMID:26088135

  8. Mechanisms for macrophage-mediated HIV-1 induction.

    PubMed

    Devadas, Krishnakumar; Hardegen, Neil J; Wahl, Larry M; Hewlett, Indira K; Clouse, Kathleen A; Yamada, Kenneth M; Dhawan, Subhash

    2004-12-01

    Viral latency is a long-term pathogenic condition in patients infected with HIV-1. Low but sustained virus replication in chronically infected cells can be activated by stimulation with proinflammatory cytokines such as TNF-alpha, IL-1 beta, or other host factors. However, the precise mechanism by which cellular activation induces latently infected cells to produce virions has remained unclear. In the present report, we present evidence that activation of HIV-1 replication in latently infected U1 or ACH2 cells by human macrophages is mediated by a rapid nuclear localization of NF-kappaB p50/p65 dimer with concomitant increased expression of proinflammatory cytokines. Multiplexed RT-PCR amplification of mRNA isolated from cocultures of macrophages and U1 and ACH2 cells showed significant induction of IL-1beta, IL-6, IL-8, TNF-alpha, and TGF-beta expression within 3 h of coincubation. Fixation of macrophages, U-1, or ACH2 cells with paraformaldehyde before coculture completely abrogated the induction of NF-kappaB subunits and HIV-1 replication, suggesting that cooperative interaction between the two cell types is an essential process for cellular activation. Pretreatment of macrophage-U1 or macrophage-ACH2 cocultures with neutralizing anti-TNF-alpha Ab down-regulated the replication of HIV-1. In addition, pretreatment of macrophage-U1 or macrophage-ACH2 cocultures with the NF-kappaB inhibitor (E)3-[(4-methylphenyl)sulfonyl]-2-propenenitrile (BAY 11-7082) prevented the induction of cytokine expression, indicating a pivotal role of NF-kappaB-mediated signaling in the reactivation of HIV-1 in latently infected cells by macrophages. These results provide a mechanism by which macrophages induce HIV-1 replication in latently infected cells.

  9. Measuring glutathione redox potential of HIV-1-infected macrophages.

    PubMed

    Bhaskar, Ashima; Munshi, MohamedHusen; Khan, Sohrab Zafar; Fatima, Sadaf; Arya, Rahul; Jameel, Shahid; Singh, Amit

    2015-01-01

    Redox signaling plays a crucial role in the pathogenesis of human immunodeficiency virus type-1 (HIV-1). The majority of HIV redox research relies on measuring redox stress using invasive technologies, which are unreliable and do not provide information about the contributions of subcellular compartments. A major technological leap emerges from the development of genetically encoded redox-sensitive green fluorescent proteins (roGFPs), which provide sensitive and compartment-specific insights into redox homeostasis. Here, we exploited a roGFP-based specific bioprobe of glutathione redox potential (E(GSH); Grx1-roGFP2) and measured subcellular changes in E(GSH) during various phases of HIV-1 infection using U1 monocytic cells (latently infected U937 cells with HIV-1). We show that although U937 and U1 cells demonstrate significantly reduced cytosolic and mitochondrial E(GSH) (approximately -310 mV), active viral replication induces substantial oxidative stress (E(GSH) more than -240 mV). Furthermore, exposure to a physiologically relevant oxidant, hydrogen peroxide (H2O2), induces significant deviations in subcellular E(GSH) between U937 and U1, which distinctly modulates susceptibility to apoptosis. Using Grx1-roGFP2, we demonstrate that a marginal increase of about ∼25 mV in E(GSH) is sufficient to switch HIV-1 from latency to reactivation, raising the possibility of purging HIV-1 by redox modulators without triggering detrimental changes in cellular physiology. Importantly, we show that bioactive lipids synthesized by clinical drug-resistant isolates of Mycobacterium tuberculosis reactivate HIV-1 through modulation of intracellular E(GSH). Finally, the expression analysis of U1 and patient peripheral blood mononuclear cells demonstrated a major recalibration of cellular redox homeostatic pathways during persistence and active replication of HIV.

  10. Interaction between Nef and INI1/SMARCB1 augments replicability of HIV-1 in resting human peripheral blood mononuclear cells.

    PubMed

    Pyeon, Dohun; Park, In-Woo

    2015-03-01

    A central feature of HIV-1 infection is the inability of entering virus to integrate into chromosomes of resting T lymphocytes unless they are mitogenically activated. In contrast, SIVpbj1.9 replicates in initially resting T lymphocytes by activating infected cells. Previous reports have shown that a difference in Nef-mediated T cell activation between HIV-1 and SIVpbj1.9 plays a critical role in the differing abilities of these viruses to replicate in resting lymphocytes. However, the molecular details of these differences are still unclear. Here, we show that infection with a chimeric virus, HSIVnef, which harbors the 5' 308 nucleotides of SIVpbj1.9 nef in place of the 5' 221 nucleotides of HIV-1 nef in the HIV-1 proviral backbone, resulted in integration of the provirus into host chromosomes without mitogenic activation and thereby replication in resting human PBMCs (hPBMCs). These results indicate that Nef is an essential viral determinant for the integration of provirus into host chromosomes in resting T cells. Using the yeast two-hybrid system, we identified integrase interactor-1 (INI1/SMARCB1) as a cellular factor that is involved in the integration process via interaction with Nef. Although INI1 interacted with both SIVpbj1.9 and HIV-1 Nefs, SIVpbj1.9 Nef, but not HIV-1 Nef, enhanced proviral integration into host DNA. Furthermore, mutational analysis revealed that the basic-amino-acid-rich amino-terminal domain in SIVpbj1.9 Nef is crucial for interaction with INI1 and virus replication in resting hPBMCs. Taken together, these data indicate that Nef is a critical viral protein for incorporating nascent proviral DNA into host chromosomes in resting PBMCs and that this occurs through interaction with INI1. This elucidates the basis for replication of the integrated provirus when the host cell is in a resting state.

  11. Sphingomyelin Synthase 2, but Not Sphingomyelin Synthase 1, Is Involved in HIV-1 Envelope-mediated Membrane Fusion*

    PubMed Central

    Hayashi, Yasuhiro; Nemoto-Sasaki, Yoko; Tanikawa, Takashi; Oka, Saori; Tsuchiya, Kiyoto; Zama, Kouta; Mitsutake, Susumu; Sugiura, Takayuki; Yamashita, Atsushi

    2014-01-01

    Membrane fusion between the viral envelope and plasma membranes of target cells has previously been correlated with HIV-1 infection. Lipids in the plasma membrane, including sphingomyelin, may be crucially involved in HIV-1 infection; however, the role of lipid-metabolic enzymes in membrane fusion remains unclear. In this study, we examined the roles of sphingomyelin synthase (SMS) in HIV-1 Env-mediated membrane fusion using a cell-cell fusion assay with HIV-1 mimetics and their target cells. We employed reconstituted cells as target cells that stably express Sms1 or Sms2 in Sms-deficient cells. Fusion susceptibility was ∼5-fold higher in Sms2-expressing cells (not in Sms1-expressing cells) than in Sms-deficient cells. The enhancement of fusion susceptibility observed in Sms2-expressing cells was reversed and reduced by Sms2 knockdown. We also found that catalytically nonactive Sms2 promoted membrane fusion susceptibility. Moreover, SMS2 co-localized and was constitutively associated with the HIV receptor·co-receptor complex in the plasma membrane. In addition, HIV-1 Env treatment resulted in a transient increase in nonreceptor tyrosine kinase (Pyk2) phosphorylation in Sms2-expressing and catalytically nonactive Sms2-expressing cells. We observed that F-actin polymerization in the region of membrane fusion was more prominent in Sms2-expressing cells than Sms-deficient cells. Taken together, our research provides insight into a novel function of SMS2 which is the regulation of HIV-1 Env-mediated membrane fusion via actin rearrangement. PMID:25231990

  12. Quantitative Correlation between Infectivity and Gp120 Density on HIV-1 Virions Revealed by Optical Trapping Virometry.

    PubMed

    DeSantis, Michael C; Kim, Jin H; Song, Hanna; Klasse, Per Johan; Cheng, Wei

    2016-06-17

    The envelope glycoprotein (Env) gp120/gp41 is required for HIV-1 infection of host cells. Although in general it has been perceived that more Env gives rise to higher infectivity, the precise quantitative dependence of HIV-1 virion infectivity on Env density has remained unknown. Here we have developed a method to examine this dependence. This method involves 1) production of a set of single-cycle HIV-1 virions with varied density of Env on their surface, 2) site-specific labeling of Env-specific antibody Fab with a fluorophore at high efficiency, and 3) optical trapping virometry to measure the number of gp120 molecules on individual HIV-1 virions. The resulting gp120 density per virion is then correlated with the infectivity of the virions measured in cell culture. In the presence of DEAE-dextran, the polycation known to enhance HIV-1 infectivity in cell culture, virion infectivity follows gp120 density as a sigmoidal dependence and reaches an apparent plateau. This quantitative dependence can be described by a Hill equation, with a Hill coefficient of 2.4 ± 0.6. In contrast, in the absence of DEAE-dextran, virion infectivity increases monotonically with gp120 density and no saturation is observed under the experimental conditions. These results provide the first quantitative evidence that Env trimers cooperate on the virion surface to mediate productive infection by HIV-1. Moreover, as a result of the low number of Env trimers on individual virions, the number of additional Env trimers per virion that is required for the optimal infectivity will depend on the inclusion of facilitating agents during infection. PMID:27129237

  13. Complement Opsonization of HIV-1 Results in Decreased Antiviral and Inflammatory Responses in Immature Dendritic Cells via CR3

    PubMed Central

    Ellegård, Rada; Crisci, Elisa; Burgener, Adam; Sjöwall, Christopher; Birse, Kenzie; Westmacott, Garrett; Hinkula, Jorma; Lifson, Jeffrey D.

    2014-01-01

    Immature dendritic cells (iDCs) in genital and rectal mucosa may be one of the first cells to come into contact with HIV-1 during sexual transmission of virus. HIV-1 activates the host complement system, which results in opsonization of virus by inactivated complement fragments, for example, iC3b. We investigated antiviral and inflammatory responses induced in human iDCs after exposure to free HIV-1 (F-HIV), complement-opsonized HIV-1 (C-HIV), and complement and Ab–opsonized HIV-1 (CI-HIV). F-HIV gave rise to a significantly higher expression of antiviral factors such as IFN-β, myxovirus resistance protein A, and IFN-stimulated genes, compared with C-HIV and CI-HIV. Additionally, F-HIV induced inflammatory factors such as IL-1β, IL-6, and TNF-α, whereas these responses were weakened or absent after C-HIV or CI-HIV exposure. The responses induced by F-HIV were TLR8-dependent with subsequent activation of IFN regulatory factor 1, p38, ERK, PI3K, and NF-κB pathways, whereas these responses were not induced by C-HIV, which instead induced activation of IFN regulatory factor 3 and Lyn. This modulation of TLR8 signaling was mediated by complement receptor 3 and led to enhanced infection. The impact that viral hijacking of the complement system has on iDC function could be an important immune evasion mechanism used by HIV-1 to establish infection in the host. PMID:25252956

  14. Exosomes from HIV-1-infected Cells Stimulate Production of Pro-inflammatory Cytokines through Trans-activating Response (TAR) RNA.

    PubMed

    Sampey, Gavin C; Saifuddin, Mohammed; Schwab, Angela; Barclay, Robert; Punya, Shreya; Chung, Myung-Chul; Hakami, Ramin M; Zadeh, Mohammad Asad; Lepene, Benjamin; Klase, Zachary A; El-Hage, Nazira; Young, Mary; Iordanskiy, Sergey; Kashanchi, Fatah

    2016-01-15

    HIV-1 infection results in a chronic illness because long-term highly active antiretroviral therapy can lower viral titers to an undetectable level. However, discontinuation of therapy rapidly increases virus burden. Moreover, patients under highly active antiretroviral therapy frequently develop various metabolic disorders, neurocognitive abnormalities, and cardiovascular diseases. We have previously shown that exosomes containing trans-activating response (TAR) element RNA enhance susceptibility of undifferentiated naive cells to HIV-1 infection. This study indicates that exosomes from HIV-1-infected primary cells are highly abundant with TAR RNA as detected by RT-real time PCR. Interestingly, up to a million copies of TAR RNA/μl were also detected in the serum from HIV-1-infected humanized mice suggesting that TAR RNA may be stable in vivo. Incubation of exosomes from HIV-1-infected cells with primary macrophages resulted in a dramatic increase of proinflammatory cytokines, IL-6 and TNF-β, indicating that exosomes containing TAR RNA could play a direct role in control of cytokine gene expression. The intact TAR molecule was able to bind to PKR and TLR3 effectively, whereas the 5' and 3' stems (TAR microRNAs) bound best to TLR7 and -8 and none to PKR. Binding of TAR to PKR did not result in its phosphorylation, and therefore, TAR may be a dominant negative decoy molecule in cells. The TLR binding through either TAR RNA or TAR microRNA potentially can activate the NF-κB pathway and regulate cytokine expression. Collectively, these results imply that exosomes containing TAR RNA could directly affect the proinflammatory cytokine gene expression and may explain a possible mechanism of inflammation observed in HIV-1-infected patients under cART.

  15. Antiretroviral Therapy for the Prevention of HIV-1 Transmission.

    PubMed

    Cohen, Myron S; Chen, Ying Q; McCauley, Marybeth; Gamble, Theresa; Hosseinipour, Mina C; Kumarasamy, Nagalingeswaran; Hakim, James G; Kumwenda, Johnstone; Grinsztejn, Beatriz; Pilotto, Jose H S; Godbole, Sheela V; Chariyalertsak, Suwat; Santos, Breno R; Mayer, Kenneth H; Hoffman, Irving F; Eshleman, Susan H; Piwowar-Manning, Estelle; Cottle, Leslie; Zhang, Xinyi C; Makhema, Joseph; Mills, Lisa A; Panchia, Ravindre; Faesen, Sharlaa; Eron, Joseph; Gallant, Joel; Havlir, Diane; Swindells, Susan; Elharrar, Vanessa; Burns, David; Taha, Taha E; Nielsen-Saines, Karin; Celentano, David D; Essex, Max; Hudelson, Sarah E; Redd, Andrew D; Fleming, Thomas R

    2016-09-01

    Background An interim analysis of data from the HIV Prevention Trials Network (HPTN) 052 trial showed that antiretroviral therapy (ART) prevented more than 96% of genetically linked infections caused by human immunodeficiency virus type 1 (HIV-1) in serodiscordant couples. ART was then offered to all patients with HIV-1 infection (index participants). The study included more than 5 years of follow-up to assess the durability of such therapy for the prevention of HIV-1 transmission. Methods We randomly assigned 1763 index participants to receive either early or delayed ART. In the early-ART group, 886 participants started therapy at enrollment (CD4+ count, 350 to 550 cells per cubic millimeter). In the delayed-ART group, 877 participants started therapy after two consecutive CD4+ counts fell below 250 cells per cubic millimeter or if an illness indicative of the acquired immunodeficiency syndrome (i.e., an AIDS-defining illness) developed. The primary study end point was the diagnosis of genetically linked HIV-1 infection in the previously HIV-1-negative partner in an intention-to-treat analysis. Results Index participants were followed for 10,031 person-years; partners were followed for 8509 person-years. Among partners, 78 HIV-1 infections were observed during the trial (annual incidence, 0.9%; 95% confidence interval [CI], 0.7 to 1.1). Viral-linkage status was determined for 72 (92%) of the partner infections. Of these infections, 46 were linked (3 in the early-ART group and 43 in the delayed-ART group; incidence, 0.5%; 95% CI, 0.4 to 0.7) and 26 were unlinked (14 in the early-ART group and 12 in the delayed-ART group; incidence, 0.3%; 95% CI, 0.2 to 0.4). Early ART was associated with a 93% lower risk of linked partner infection than was delayed ART (hazard ratio, 0.07; 95% CI, 0.02 to 0.22). No linked infections were observed when HIV-1 infection was stably suppressed by ART in the index participant. Conclusions The early initiation of ART led to a sustained

  16. Constructing the Average Natural History of HIV-1 Infection

    NASA Astrophysics Data System (ADS)

    Diambra, L.; Capurro, A.; Malta, C. P.

    2007-05-01

    Many aspects of the natural course of the HIV-1 infection remains unclear, despite important efforts towards understanding its long-term dynamics. Using a scaling approach that places progression markers (viral load, CD4+, CD8+) of many individuals on a single average natural course of disease progression, we introduce the concept of inter-individual scaling and time scaling. Our quantitative assessment of the natural course of HIV-1 infection indicates that the dynamics of the evolution for the individual that developed AIDS (opportunistic infections) is different from that of the individual that did not develop AIDS. This means that the rate of progression is not relevant for the infection evolution.

  17. Can we cure HIV-1-associated nephropathy in transgenic mice?

    PubMed

    Ray, Patricio E

    2012-05-01

    HIV-1-associated nephropathy (HIVAN) is a rapidly progressive form of focal segmental glomerulosclerosis. HIV transgenic mice can develop a HIVAN-like renal disease. Zhong et al. show that the oral administration of a cyclic nucleotide phosphodiesterase 4 inhibitor and a retinoic acid receptor-α agonist can prevent the development of HIVAN in transgenic mice, acting through a cAMP-dependent mechanism that is independent of HIV-1 genes. These findings suggest that endogenous host factors play a critical role in HIVAN.

  18. Can we cure HIV-1 associated nephropathy in transgenic mice?

    PubMed Central

    Ray, Patricio E.

    2012-01-01

    HIV-1 associated nephropathy is a rapidly progressive form of focal segmental glomerulosclerosis typically seen in patients of African ancestry. HIV-transgenic mice can develop an HIVAN-like renal disease. Zhong et al. show that the oral administration of a cyclic nucleotide phosphodiesterase 4 inhibitor and a retinoic acid receptor-alpha agonist can prevent the development of HIVAN in transgenic mice, acting through a cAMP dependent mechanism that is independent of HIV-1 genes. These findings suggest that endogenous host factors play a critical role in HIVAN. PMID:22499139

  19. The Latent Reservoir for HIV-1: How Immunologic Memory and Clonal Expansion Contribute to HIV-1 Persistence.

    PubMed

    Murray, Alexandra J; Kwon, Kyungyoon J; Farber, Donna L; Siliciano, Robert F

    2016-07-15

    Combination antiretroviral therapy (ART) for HIV-1 infection reduces plasma virus levels to below the limit of detection of clinical assays. However, even with prolonged suppression of viral replication with ART, viremia rebounds rapidly after treatment interruption. Thus, ART is not curative. The principal barrier to cure is a remarkably stable reservoir of latent HIV-1 in resting memory CD4(+) T cells. In this review, we consider explanations for the remarkable stability of the latent reservoir. Stability does not appear to reflect replenishment from new infection events but rather normal physiologic processes that provide for immunologic memory. Of particular importance are proliferative processes that drive clonal expansion of infected cells. Recent evidence suggests that in some infected cells, proliferation is a consequence of proviral integration into host genes associated with cell growth. Efforts to cure HIV-1 infection by targeting the latent reservoir may need to consider the potential of latently infected cells to proliferate.

  20. The Latent Reservoir for HIV-1: How Immunologic Memory and Clonal Expansion Contribute to HIV-1 Persistence.

    PubMed

    Murray, Alexandra J; Kwon, Kyungyoon J; Farber, Donna L; Siliciano, Robert F

    2016-07-15

    Combination antiretroviral therapy (ART) for HIV-1 infection reduces plasma virus levels to below the limit of detection of clinical assays. However, even with prolonged suppression of viral replication with ART, viremia rebounds rapidly after treatment interruption. Thus, ART is not curative. The principal barrier to cure is a remarkably stable reservoir of latent HIV-1 in resting memory CD4(+) T cells. In this review, we consider explanations for the remarkable stability of the latent reservoir. Stability does not appear to reflect replenishment from new infection events but rather normal physiologic processes that provide for immunologic memory. Of particular importance are proliferative processes that drive clonal expansion of infected cells. Recent evidence suggests that in some infected cells, proliferation is a consequence of proviral integration into host genes associated with cell growth. Efforts to cure HIV-1 infection by targeting the latent reservoir may need to consider the potential of latently infected cells to proliferate. PMID:27382129

  1. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16.

    PubMed

    Pancera, Marie; Shahzad-Ul-Hussan, Syed; Doria-Rose, Nicole A; McLellan, Jason S; Bailer, Robert T; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K; Staupe, Ryan P; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E; Blinn, Julie; Alam, S Munir; Haynes, Barton F; Amin, Mohammed N; Wang, Lai-Xi; Burton, Dennis R; Koff, Wayne C; Nabel, Gary J; Mascola, John R; Bewley, Carole A; Kwong, Peter D

    2013-07-01

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1-V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1-V2, showing an epitope comprising both high mannose-type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1-glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  2. Structural basis for diverse N-glycan recognition by HIV-1-neutralizing V1-V2-directed antibody PG16

    SciTech Connect

    Pancera, Marie; Shahzad-ul-Hussan, Syed; Doria-Rose, Nicole A.; McLellan, Jason S.; Bailer, Robert T.; Dai, Kaifan; Loesgen, Sandra; Louder, Mark K.; Staupe, Ryan P.; Yang, Yongping; Zhang, Baoshan; Parks, Robert; Eudailey, Joshua; Lloyd, Krissey E.; Blinn, Julie; Alam, S. Munir; Haynes, Barton F.; Amin, Mohammed N.; Wang, Lai-Xi; Burton, Dennis R.; Koff, Wayne C.; Nabel, Gary J.; Mascola, John R.; Bewley, Carole A; Kwong, Peter D.

    2013-08-05

    HIV-1 uses a diverse N-linked-glycan shield to evade recognition by antibody. Select human antibodies, such as the clonally related PG9 and PG16, recognize glycopeptide epitopes in the HIV-1 V1–V2 region and penetrate this shield, but their ability to accommodate diverse glycans is unclear. Here we report the structure of antibody PG16 bound to a scaffolded V1–V2, showing an epitope comprising both high mannose–type and complex-type N-linked glycans. We combined structure, NMR and mutagenesis analyses to characterize glycan recognition by PG9 and PG16. Three PG16-specific residues, arginine, serine and histidine (RSH), were critical for binding sialic acid on complex-type glycans, and introduction of these residues into PG9 produced a chimeric antibody with enhanced HIV-1 neutralization. Although HIV-1–glycan diversity facilitates evasion, antibody somatic diversity can overcome this and can provide clues to guide the design of modified antibodies with enhanced neutralization.

  3. Incidence, Prevalence and Epidemiology of Herpes Simplex Virus-2 in HIV-1-positive and HIV-1-negative Adolescents

    PubMed Central

    Sudenga, Staci L.; Kempf, Mirjam-Colette; McGwin, Gerald; Wilson, Craig M.; Hook, Edward; Shrestha, Sadeep

    2012-01-01

    Background Several studies have assessed risk factors associated with herpes simplex virus-2 (HSV-2) prevalence in adults; however, few have focused on HSV-2 incidence, particularly in adolescents. The objective of this study was to determine HSV-2 prevalence and incidence and associated risk factors in a HIV-1-positive and at risk HIV-1-negative adolescent population. Methods Sera were tested for HSV-2 antibodies in 518 adolescents in the Reaching for Excellence in Adolescent Care and Health (REACH) cohort at baseline and again at the final follow-up visit. Prevalence at baseline and incidence (per person years) of HSV-2 infection were calculated. Furthermore, among HIV-1-positive individuals, a subgroup analysis was performed to assess risk factors for HSV-2 infection. Conditional logistic regression was used to estimate odds ratios (OR) and p-values (p) for associations between CD4+ T-cell (CD4+) count, HIV-1 viral load (VL), and HSV-2 acquisition, adjusting for antiretroviral therapy use, other sexually transmitted infections, gender, race, and number of sexual partners. Results At baseline, 179 (35%) subjects were HSV-2 positive, with an additional 47 (16%) new cases being identified during a median follow-up time of 1.95 years and an incidence rate of 7.35 cases per 100 person years (py). Several risk factors were associated with HSV-2 prevalence (being female, non-Hispanic, uncertainty of sexual preference, and HIV-1 positive) and incidence (using drugs, alcohol, and number of new sexual partners). Among HIV-1 positives, an increase in CD4+ count by 50 cell/mm3 (OR, 1.17; 95% CI 1.04–1.31, p=0.008) was associated with HSV-2 acquisition. Conclusions The high prevalence and incidence of HSV-2 infection among adolescents, compared to the general population at this age group suggests a critical need for screening and preventive programs among this targeted group. PMID:22421698

  4. A Chimeric HIV-1 gp120 Fused with Vaccinia Virus 14K (A27) Protein as an HIV Immunogen

    PubMed Central

    Vijayan, Aneesh; García-Arriaza, Juan; C. Raman, Suresh; Conesa, José Javier; Chichón, Francisco Javier; Santiago, César; Sorzano, Carlos Óscar S.; Carrascosa, José L.; Esteban, Mariano

    2015-01-01

    In the HIV vaccine field, there is a need to produce highly immunogenic forms of the Env protein with the capacity to trigger broad B and T-cell responses. Here, we report the generation and characterization of a chimeric HIV-1 gp120 protein (termed gp120-14K) by fusing gp120 from clade B with the vaccinia virus (VACV) 14K oligomeric protein (derived from A27L gene). Stable CHO cell lines expressing HIV-1 gp120-14K protein were generated and the protein purified was characterized by size exclusion chromatography, electron microscopy and binding to anti-Env antibodies. These approaches indicate that gp120-14K protein is oligomeric and reacts with a wide spectrum of HIV-1 neutralizing antibodies. Furthermore, in human monocyte-derived dendritic cells (moDCs), gp120-14K protein upregulates the levels of several proinflammatory cytokines and chemokines associated with Th1 innate immune responses (IL-1β, IFN-γ, IL-6, IL-8, IL-12, RANTES). Moreover, we showed in a murine model, that a heterologous prime/boost immunization protocol consisting of a DNA prime with a plasmid expressing gp120-14K protein followed by a boost with MVA-B [a recombinant modified vaccinia virus Ankara (MVA) expressing HIV-1 gp120, Gag, Pol and Nef antigens from clade B], generates stronger, more polyfunctional, and greater effector memory HIV-1-specific CD4+ and CD8+ T-cell immune responses, than immunization with DNA-gp120/MVA-B. The DNA/MVA protocol was superior to immunization with the combination of protein/MVA and the latter was superior to a prime/boost of MVA/MVA or protein/protein. In addition, these immunization protocols enhanced antibody responses against gp120 of the class IgG2a and IgG3, together favoring a Th1 humoral immune response. These results demonstrate that fusing HIV-1 gp120 with VACV 14K forms an oligomeric protein which is highly antigenic as it activates a Th1 innate immune response in human moDCs, and in vaccinated mice triggers polyfunctional HIV-1-specific adaptive

  5. Curcumin inhibits HIV-1 by promoting Tat protein degradation

    PubMed Central

    Ali, Amjad; Banerjea, Akhil C.

    2016-01-01

    HIV-1 Tat is an intrinsically unfolded protein playing a pivotal role in viral replication by associating with TAR region of viral LTR. Unfolded proteins are degraded by 20S proteasome in an ubiquitin independent manner. Curcumin is known to activate 20S proteasome and promotes the degradation of intrinsically unfolded p53 tumor suppressor protein. Since HIV-1 Tat protein is largerly unfolded, we hypothesized that Tat may also be targeted through this pathway. Curcumin treated Tat transfected HEK-293T cells showed a dose and time dependent degradation of Tat protein. Contrary to this HIV-1 Gag which is a properly folded protein, remained unaffected with curcumin. Semi-quantitative RT-PCR analysis showed that curcumin treatment did not affect Tat gene transcription. Curcumin increased the rate of Tat protein degradation as shown by cycloheximide (CHX) chase assay. Degradation of the Tat protein is accomplished through proteasomal pathway as proteasomal inhibitor MG132 blocked Tat degradation. Curcumin also decreased Tat mediated LTR promoter transactivation and inhibited virus production from HIV-1 infected cells. Taken together our study reveals a novel observation that curcumin causes potent degradation of Tat which may be one of the major mechanisms behind its anti HIV activity. PMID:27283735

  6. Curcumin inhibits HIV-1 by promoting Tat protein degradation.

    PubMed

    Ali, Amjad; Banerjea, Akhil C

    2016-01-01

    HIV-1 Tat is an intrinsically unfolded protein playing a pivotal role in viral replication by associating with TAR region of viral LTR. Unfolded proteins are degraded by 20S proteasome in an ubiquitin independent manner. Curcumin is known to activate 20S proteasome and promotes the degradation of intrinsically unfolded p53 tumor suppressor protein. Since HIV-1 Tat protein is largerly unfolded, we hypothesized that Tat may also be targeted through this pathway. Curcumin treated Tat transfected HEK-293T cells showed a dose and time dependent degradation of Tat protein. Contrary to this HIV-1 Gag which is a properly folded protein, remained unaffected with curcumin. Semi-quantitative RT-PCR analysis showed that curcumin treatment did not affect Tat gene transcription. Curcumin increased the rate of Tat protein degradation as shown by cycloheximide (CHX) chase assay. Degradation of the Tat protein is accomplished through proteasomal pathway as proteasomal inhibitor MG132 blocked Tat degradation. Curcumin also decreased Tat mediated LTR promoter transactivation and inhibited virus production from HIV-1 infected cells. Taken together our study reveals a novel observation that curcumin causes potent degradation of Tat which may be one of the major mechanisms behind its anti HIV activity. PMID:27283735

  7. Structural Insight into HIV-1 Restriction by MxB

    PubMed Central

    Alvarez, Frances Joan D.; Summers, Brady J.; Dewdney, Tamaria G.; Aiken, Christopher; Zhang, Peijun; Engelman, Alan; Xiong, Yong

    2014-01-01

    Summary The myxovirus resistance (Mx) proteins are interferon-induced dynamin GTPases that can inhibit a variety of viruses. Recently, MxB, but not MxA, was shown to restrict HIV-1 by an unknown mechanism that likely occurs in close proximity to the host cell nucleus and involves the viral capsid. Here, we present the crystal structure of MxB and reveal determinants involved in HIV-1 restriction. MxB adopts an extended anti-parallel dimer and dimerization, but not higher-ordered oligomerization, is critical for restriction. Although MxB is structurally similar to MxA, the orientation of individual domains differs between MxA and MxB and their antiviral functions rely on separate determinants, indicating distinct mechanisms for virus inhibition. Additionally, MxB directly binds the HIV-1 capsid and this interaction depends on dimerization and the N-terminus of MxB as well as the assembled capsid lattice. These insights establish a framework for understanding the mechanism by which MxB restricts HIV-1. PMID:25312384

  8. Effects of human SAMHD1 polymorphisms on HIV-1 susceptibility

    SciTech Connect

    White, Tommy E.; Brandariz-Nuñez, Alberto; Valle-Casuso, Jose Carlos; Knowlton, Caitlin; Kim, Baek; Sawyer, Sara L.; Diaz-Griffero, Felipe

    2014-07-15

    SAMHD1 is a human restriction factor that prevents efficient infection of macrophages, dendritic cells and resting CD4+ T cells by HIV-1. Here we explored the antiviral activity and biochemical properties of human SAMHD1 polymorphisms. Our studies focused on human SAMHD1 polymorphisms that were previously identified as evolving under positive selection for rapid amino acid replacement during primate speciation. The different human SAMHD1 polymorphisms were tested for their ability to block HIV-1, HIV-2 and equine infectious anemia virus (EIAV). All studied SAMHD1 variants block HIV-1, HIV-2 and EIAV infection when compared to wild type. We found that these variants did not lose their ability to oligomerize or to bind RNA. Furthermore, all tested variants were susceptible to degradation by Vpx, and localized to the nuclear compartment. We tested the ability of human SAMHD1 polymorphisms to decrease the dNTP cellular levels. In agreement, none of the different SAMHD1 variants lost their ability to reduce cellular levels of dNTPs. Finally, we found that none of the tested human SAMHD1 polymorphisms affected the ability of the protein to block LINE-1 retrotransposition. - Highlights: • Human SAMHD1 single-nucleotide polymorphisms block HIV-1 and HIV-2 infection. • SAMHD1 polymorphisms do not affect its ability to block LINE-1 retrotransposition. • SAMHD1 polymorphisms decrease the cellular levels of dNTPs.

  9. Is the central nervous system a reservoir of HIV-1?

    PubMed Central

    Gray, Lachlan R.; Roche, Michael; Flynn, Jacqueline K.; Wesselingh, Steve L.; Gorry, Paul R.; Churchill, Melissa J.

    2014-01-01

    Purpose of the review To summarize the evidence in the literature that supports the CNS as a viral reservoir for HIV-1 and to prioritise future research efforts. Recent findings HIV-1 DNA has been detected in brain tissue of patients with undetectable viral load or neurocognitive disorders, and is associated with long-lived cells such as astrocytes and microglia. In neurocognitively normal patients, HIV-1 can be found at high frequency in these cells (4% of astrocytes and 20% of macrophages). CNS cells have unique molecular mechanisms to suppress viral replication and induce latency, which include increased expression of dominant negative transcription factors and suppressive epigenetic factors. There is also evidence of continued inflammation in patients lacking a CNS viral load, suggesting the production and activity of viral neurotoxins (for example Tat). Summary Together, these findings provide evidence that the CNS can potentially act as a viral reservoir of HIV-1. However, the majority of these studies were performed in historical cohorts (absence of cART or presence of viral load) which do not reflect modern day patients (cART-treated and undetectable viral load). Future studies will need to examine patient samples with these characteristics to conclusively determine if the CNS represents a relevant and important viral reservoir. PMID:25203642

  10. Harnessing the protective potential of HIV-1 neutralizing antibodies

    PubMed Central

    Smith, S Abigail; Derdeyn, Cynthia A

    2016-01-01

    Recent biological, structural, and technical advances are converging within the HIV-1 vaccine field to harness the power of antibodies for prevention and therapy. Numerous monoclonal antibodies with broad neutralizing activity against diverse HIV-1 isolates have now been identified, revealing at least five sites of vulnerability on the envelope (Env) glycoproteins. While there are practical and technological barriers blocking a clear path from broadly neutralizing antibodies (bNAb) to a protective vaccine, this is not a dead end. Scientists are revisiting old approaches with new technology, cutting new trails through unexplored territory, and paving new roads in the hopes of preventing HIV-1 infection. Other promising avenues to capitalize on the power of bNAbs are also being pursued, such as passive antibody immunotherapy and gene therapy approaches. Moreover, non-neutralizing antibodies have inhibitory activities that could have protective potential, alone or in combination with bNAbs. With a new generation of bNAbs, and a clinical trial that associated antibodies with reduced acquisition, the field is closer than ever to developing strategies to use antibodies against HIV-1. PMID:26918160

  11. HIV-1 Vpr—a still “enigmatic multitasker”

    PubMed Central

    Guenzel, Carolin A.; Hérate, Cécile; Benichou, Serge

    2014-01-01

    Like other HIV-1 auxiliary proteins, Vpr is conserved within all the human (HIV-1, HIV-2) and simian (SIV) immunodeficiency viruses. However, Vpr and homologous HIV-2, and SIV Vpx are the only viral auxiliary proteins specifically incorporated into virus particles through direct interaction with the Gag precursor, indicating that this presence in the core of the mature virions is mainly required for optimal establishment of the early steps of the virus life cycle in the newly infected cell. In spite of its small size, a plethora of effects and functions have been attributed to Vpr, including induction of cell cycle arrest and apoptosis, modulation of the fidelity of reverse transcription, nuclear import of viral DNA in macrophages and other non-dividing cells, and transcriptional modulation of viral and host cell genes. Even if some more recent studies identified a few cellular targets that HIV-1 Vpr may utilize in order to perform its different tasks, the real role and functions of Vpr during the course of natural infection are still enigmatic. In this review, we will summarize the main reported functions of HIV-1 Vpr and their significance in the context of the viral life cycle. PMID:24744753

  12. Differentially-Expressed Pseudogenes in HIV-1 Infection.

    PubMed

    Gupta, Aditi; Brown, C Titus; Zheng, Yong-Hui; Adami, Christoph

    2015-10-01

    Not all pseudogenes are transcriptionally silent as previously thought. Pseudogene transcripts, although not translated, contribute to the non-coding RNA pool of the cell that regulates the expression of other genes. Pseudogene transcripts can also directly compete with the parent gene transcripts for mRNA stability and other cell factors, modulating their expression levels. Tissue-specific and cancer-specific differential expression of these "functional" pseudogenes has been reported. To ascertain potential pseudogene:gene interactions in HIV-1 infection, we analyzed transcriptomes from infected and uninfected T-cells and found that 21 pseudogenes are differentially expressed in HIV-1 infection. This is interesting because parent genes of one-third of these differentially-expressed pseudogenes are implicated in HIV-1 life cycle, and parent genes of half of these pseudogenes are involved in different viral infections. Our bioinformatics analysis identifies candidate pseudogene:gene interactions that may be of significance in HIV-1 infection. Experimental validation of these interactions would establish that retroviruses exploit this newly-discovered layer of host gene expression regulation for their own benefit.

  13. Chemical crosslinking of the subunits of HIV-1 reverse transcriptase.

    PubMed Central

    Debyser, Z.; De Clercq, E.

    1996-01-01

    The reverse transcriptase (RT) of the human immunodeficiency virus type 1 (HIV-1) is composed of two subunits of 66 and 51 kDa in a 1 to 1 ratio. Because dimerization is a prerequisite for enzymatic activity, interference with the dimerization process could constitute an alternative antiviral strategy for RT inhibition. Here we describe an in vitro assay for the study of the dimerization state of HIV-1 reverse transcriptase based on chemical crosslinking of the subunits with dimethylsuberimidate. Crosslinking results in the formation of covalent bonds between the subunits, so that the crosslinked species can be resolved by denaturing gel electrophoresis. Crosslinked RT species with molecular weight greater than that of the dimeric form accumulate during a 1-15-min time course. Initial evidence suggests that those high molecular weight species represent trimers and tetramers and may be the result of intramolecular crosslinking of the subunits of a higher-order RT oligomer. A peptide that corresponds to part of the tryptophan repeat motif in the connection domain of HIV-1 RT inhibits crosslink formation as well as enzymatic activity. The crosslinking assay thus allows the investigation of the effect of inhibitors on the dimerization of HIV-1 RT. PMID:8745406

  14. High levels of CC-chemokine expression and downregulated levels of CCR5 during HIV-1/HTLV-1 and HIV-1/HTLV-2 coinfections.

    PubMed

    Oo, Z; Barrios, C S; Castillo, L; Beilke, M A

    2015-05-01

    The human T-cell lymphotropic virus type 1 (HTLV-1) and HTLV-2 are common copathogens among Human Immunodeficiency Virus (HIV)-infected individuals. HTLV-2 may confer a survival benefit among patients with HIV-1/HTLV-2 coinfections, along with lower plasma HIV-1 levels and delayed rates of CD4(+) T-cell decline. These effects have been attributed to the ability of the HTLV-2 viral transactivating Tax2 protein to induce the production of high levels of antiviral CC-chemokines and to downregulate expression of the CCR5 receptor, resulting in impaired entry of HIV-1 into CD4(+) T-cells. This study investigated the innate immunity of coinfected HIV/HTLV individuals by testing the ability of patient PBMCs to produce CC-chemokines in association CCR5 receptor modulation. The cellular proliferative responses of HIV/HTLV coinfected versus HIV monoinfected individuals were also evaluated. Higher levels of MIP-1α, MIP-1β, and RANTES (P < 0.05) were found in HIV-1/HTLV-2 coinfected group compared to HIV-1 monoinfected population. Upregulated levels of RANTES were shown in HIV-1/HTLV-1 after 1 and 3 days of culture (P < 0.05). Lymphocytes from HIV-1/HTLV-2 coinfected individuals showed significant CCR5 downregulation after 1 and 3 days of culture compared to lymphocytes from HIV-1 and uninfected groups (P < 0.05). Lower percentages of CCR5-positive cells were found in HIV-1/HTLV-1 coinfected after 3 days of incubation (P < 0.05). Levels of proliferation were significantly higher in the HIV-1/HTLV-1 group compared to HIV-1 alone (P < 0.05). HTLV-2 and HTLV-1 infections may induce the involvement of innate immunity against HIV-1 via stimulation of CC-chemokines and receptors, potentially modifying CCR5/HIV-1 binding and HIV-1 progression in coinfected individuals.

  15. Wide distribution of two subtypes of HIV-1 in Thailand.

    PubMed

    Ou, C Y; Takebe, Y; Luo, C C; Kalish, M; Auwanit, W; Bandea, C; de la Torre, N; Moore, J L; Schochetman, G; Yamazaki, S

    1992-08-01

    Scientists wanted to identify the genetic characteristics of 2 HIV-1 subtypes in Thailand. Staff from regional laboratories of the Ministry of Public Health took blood samples from people in various high risk groups and from all regions of the country. Staff at the National Institutes of Health in Bangkok then did lymphocyte separation, DNA extraction, and virus culture. They took the extracted DNA specimens and sent them to the US Centers for Disease Control where scientists did serologic testing, polymerase chain reaction, and sequence determination. They used Kimura's method to study sequence variations. They sequenced 300 nucleotides, including the C2-V3 domains of HIV-1 envelope gene and/or hybridization. Every risk group had HIV-1 subtype A, but subtype B was mostly found in drug users. Subtype A had spread mainly among heterosexuals. The mean intraperson variation for subtypes A and B stood at 2% and 2.7%, respectively, while the interperson variation within subtype A and B stood at 3.8% and 3.7%, respectively. The mean interperson variation between subtypes A and B from different persons was 18.1%. Phylogenetic tree analysis showed that subtype B identified with about 85% of the sequence as that of the North American isolates, making it more closely related to them than to African isolates (about 75% sequence identity). On the other hand, subtype A had a GPGQ motif at the V3 crown which was common among African HIV-1 isolates. Antibodies which usually recognize HIV-1 MN strains (which have the GPGR motif) may not react wholly with the V3 loop from the Thailand subtype A viruses, thus the GPGQ motif at the V3 crown may pose a problem. Now for the first time, scientists can follow the natural history of 2 HIV-1 subtypes and determine their relative pathogenicity and transmission efficiency between adults or from mother to infant. The relative homogeneity of the HIV-1 strains in Thailand presents a theoretical advantage in designing vaccines for potential

  16. Structural modeling of Vpu from HIV-1 based on solid-state NMR observables

    NASA Astrophysics Data System (ADS)

    Ahn, SeonJoo; Lim, GyuTae; Nam, Seungyoon; Lee, Jinhyuk

    2014-04-01

    Vpu is one of the accessory proteins of HIV-1, and is involved in viral particle release. Viral particle release is enhanced by two proposed functions of Vpu: (i) tetherin interaction and (ii) membrane polarization. Two Vpu functions in viral particle release are still controversial. Here, we investigated the proposed functions by extensive structural modeling of Vpu based on solid-state NMR (Nuclear Magnetic Resonance) observables. We found that Vpu can co-exist in two structural forms: left-handed and right-handed conformation. The co-existence of the two conformations provides a clue to reconcile the controversial issue of its two functions in virus particle release.

  17. Accuracy of the TRUGENE HIV-1 Genotyping Kit

    PubMed Central

    Grant, Robert M.; Kuritzkes, Daniel R.; Johnson, Victoria A.; Mellors, John W.; Sullivan, John L.; Swanstrom, Ronald; D'Aquila, Richard T.; Van Gorder, Mark; Holodniy, Mark; Lloyd, Jr., Robert M.; Reid, Caroline; Morgan, Gillian F.; Winslow, Dean L.

    2003-01-01

    Drug resistance and poor virological responses are associated with well-characterized mutations in the viral reading frames that encode the proteins that are targeted by currently available antiretroviral drugs. An integrated system was developed that includes target gene amplification, DNA sequencing chemistry (TRUGENE HIV-1 Genotyping Kit), and hardware and interpretative software (the OpenGene DNA Sequencing System) for detection of mutations in the human immunodeficiency virus type 1 (HIV-1) protease and reverse transcriptase sequences. The integrated system incorporates reverse transcription-PCR from extracted HIV-1 RNA, a coupled amplification and sequencing step (CLIP), polyacrylamide gel electrophoresis, semiautomated analysis of data, and generation of an interpretative report. To assess the accuracy and robustness of the assay system, 270 coded plasma specimens derived from nine patients were sent to six laboratories for blinded analysis. All specimens contained HIV-1 subtype B viruses. Results of 270 independent assays were compared to “gold standard” consensus sequences of the virus populations determined by sequence analysis of 16 to 20 clones of viral DNA amplicons derived from two independent PCRs using primers not used in the kit. The accuracy of the integrated system for nucleotide base identification was 98.7%, and the accuracy for codon identification at 54 sites associated with drug resistance was 97.6%. In a separate analysis of plasma spiked with infectious molecular clones, the assay reproducibly detected all 72 different drug resistance mutations that were evaluated. There were no significant differences in accuracy between laboratories, between technologists, between kit lots, or between days. This integrated assay system for the detection of HIV-1 drug resistance mutations has a high degree of accuracy and reproducibility in several laboratories. PMID:12682149

  18. Functional and Structural Analysis of the Internal Ribosome Entry Site Present in the mRNA of Natural Variants of the HIV-1

    PubMed Central

    Vallejos, Maricarmen; Carvajal, Felipe; Pino, Karla; Navarrete, Camilo; Ferres, Marcela; Huidobro-Toro, Juan Pablo; Sargueil, Bruno; López-Lastra, Marcelo

    2012-01-01

    The 5′untranslated regions (UTR) of the full length mRNA of the HIV-1 proviral clones pNL4.3 and pLAI, harbor an internal ribosomal entry site (IRES). In this study we extend this finding by demonstrating that the mRNA 5′UTRs of natural variants of HIV-1 also exhibit IRES-activity. Cap-independent translational activity was demonstrated using bicistronic mRNAs in HeLa cells and in Xenopus laevis oocytes. The possibility that expression of the downstream cistron in these constructs was due to alternative splicing or to cryptic promoter activity was ruled out. The HIV-1 variants exhibited significant 5′UTR nucleotide diversity with respect to the control sequence recovered from pNL4.3. Interestingly, translational activity from the 5′UTR of some of the HIV-1 variants was enhanced relative to that observed for the 5′UTR of pNL4.3. In an attempt to explain these findings we probed the secondary structure of the variant HIV-1 5′UTRs using enzymatic and chemical approaches. Yet subsequent structural analyses did not reveal significant variations when compared to the pNL4.3-5′UTR. Thus, the increased IRES-activity observed for some of the HIV-1 variants cannot be ascribed to a specific structural modification. A model to explain these findings is proposed. PMID:22496887

  19. The thalidomide analogue CC-3052 inhibits HIV-1 and tumour necrosis factor-alpha (TNF-α) expression in acutely and chronically infected cells in vitro

    PubMed Central

    La Maestra, L; Zaninoni, A; Marriott, J B; Lazzarin, A; Dalgleish, A G; Barcellini, W

    2000-01-01

    We investigated the in vitro effect of the water-soluble, highly stable thalidomide analogue CC-3052 on HIV-1 expression and TNF-α production in latently infected promonocytic U1 cells, acutely infected T cells and monocyte-derived human macrophages (MDM), and in mitogen-stimulated ex vivo cultures from patients with primary acute HIV-1 infection. HIV-1 expression was assessed by Northern blot analysis of RNAs, and ELISA for p24 antigen release and reverse transcriptase (RT) activity. TNF-α expression was evaluated by RT-polymerase chain reaction (PCR)-ELISA for mRNA and ELISA for protein secretion. We demonstrated that CC-3052 is able to inhibit HIV-1 expression, as evaluated by mRNA, p24 release and RT activity, in phorbol myristate acetate (PMA)- and cytokine-stimulated U1 cells. Furthermore, CC-3052 inhibited HIV-1 expression, as evaluated by p24 and RT activity, in acutely infected MDM and T cells. As far as TNF-α is concerned, CC-3052 significantly reduced TNF-α mRNA and protein secretion in PMA-stimulated U937 and U1 cells, and in PMA-stimulated uninfected and acutely infected MDM. Consistently, the addition of CC-3052 reduced TNF-α production in phytohaemagglutinin (PHA) and lipopolysaccharide (LPS)-stimulated whole blood cultures from patients during the primary acute phase of HIV-1 infection. Since TNF-α is among the most potent enhancers of HIV-1 expression, the effect of CC-3052 on TNF-α may account for its inhibitory activity on HIV-1 expression. Given the well documented immunopathological role of TNF-α and its correlation with viral load, advanced disease and poor prognosis, CC-3052 could be an interesting drug for the design of therapeutic strategies in association with anti-retroviral agents. PMID:10606973

  20. Inhibition of HIV-1 Tat-mediated LTR transactivation and HIV-1 infection by anti-Tat single chain intrabodies.

    PubMed Central

    Mhashilkar, A M; Bagley, J; Chen, S Y; Szilvay, A M; Helland, D G; Marasco, W A

    1995-01-01

    Genes encoding the rearranged immunoglobulin heavy and light chain variable regions of anti-HIV-1 Tat, exon 1 or exon 2 specific monoclonal antibodies have been used to construct single chain intracellular antibodies 'intrabodies' for expression in the cytoplasm of mammalian cells. These anti-Tat single chain intrabodies (anti-Tat sFvs) are additionally modified with a C-terminal human C kappa domain to increase cytoplasmic stability and/or the C-terminal SV40 nuclear localization signal to direct the nascent intrabody to the nuclear compartment, respectively. The anti-Tat sFvs with specific binding activity against the N-terminal activation domain of Tat, block Tat-mediated transactivation of HIV-1 LTR as well as intracellular trafficking of Tat in mammalian cells. As a result, the transformed lymphocytes expressing anti-Tat sFvs are resistant to HIV-1 infection. Thus, these studies demonstrate that stably expressed single chain intrabodies and their modified forms can effectively target molecules in the cytoplasm and nuclear compartments of eukaryotic cells. Furthermore, these studies suggest that anti-Tat sFvs used either alone or in combination with other genetically based strategies may be useful for the gene therapy of HIV-1 infection and AIDS. Images PMID:7537216

  1. Performance of rapid tests for discrimination between HIV-1 and/or HIV-2 infections.

    PubMed

    Gautheret-Dejean, Agnès; Bocobza, Jonathan; Brunet, Sylvie; Damond, Florence; Plantier, Jean-Christophe; Barin, Francis

    2015-12-01

    Major differences exist between HIV-1 and HIV-2 in terms of epidemiology, pathogenicity, sensitivity to antiretrovirals. Determining the type of HIV infecting a patient is essential for management. The aim of this study was to evaluate the ability of simple/rapid tests to differentiate between HIV-1 and/or HIV-2 infections. We analyzed 116 samples from patients infected with HIV-1 (n = 61), HIV-2 (n = 47), or HIV-1+HIV-2 (n = 8) at the chronic stage of infection. Each sample was tested with SD Bioline HIV-1/2 3.0, ImmunoFlow HIV1-HIV2, ImmunoFlow HIV1-HIV2 (WB), Genie III HIV-1/HIV-2, ImmunoComb HIV1&2 BiSpot. HIV-1, or HIV-2 single infection was identified with a sensitivity ranging from 90% to 100%. The ability to detect dual infection was less sensitive (12.5-100%). SD Bioline HIV-1/2 3.0, ImmunoFlow HIV1-HIV2, and Genie III were unable to detect HIV-1 group O infection in one, one and two cases, respectively. The specificity of detection of HIV-1, HIV-2, or HIV-1+HIV-2 antibodies differed greatly (36-100%). ImmunoComb BiSpot had the highest sensitivity values (99-100% for HIV-1, 98% for HIV-2, and 75-87.5% for dual infection) and specificity values (94-100% for HIV-1, 100% for HIV-2, and 97-100% for dual infection). In conclusion, this study showed that no single rapid test had a perfect sensitivity/specificity ratio, particularly in the case of the double infections.

  2. Neutralization resistance of virological synapse-mediated HIV-1 Infection is regulated by the gp41 cytoplasmic tail.

    PubMed

    Durham, Natasha D; Yewdall, Alice W; Chen, Ping; Lee, Rebecca; Zony, Chati; Robinson, James E; Chen, Benjamin K

    2012-07-01

    Human immunodeficiency virus type 1 (HIV-1) infection can spread efficiently from infected to uninfected T cells through adhesive contacts called virological synapses (VSs). In this process, cell-surface envelope glycoprotein (Env) initiates adhesion and viral transfer into an uninfected recipient cell. Previous studies have found some HIV-1-neutralizing patient sera to be less effective at blocking VS-mediated infection than infection with cell-free virus. Here we employ sensitive flow cytometry-based infection assays to measure the inhibitory potency of HIV-1-neutralizing monoclonal antibodies (MAb) and HIV-1-neutralizing patient sera against cell-free and VS-mediated infection. To various degrees, anti-Env MAbs exhibited significantly higher 50% inhibitory concentration (IC(50)s) against VS-mediated infection than cell-free infection. Notably, the MAb 17b, which binds a CD4-induced (CD4i) epitope on gp120, displayed a 72-fold reduced efficacy against VS-mediated inocula compared to cell-free inocula. A mutant with truncation mutation in the gp41 cytoplasmic tail (CT) which is unable to modulate Env fusogenicity in response to virus particle maturation but which can still engage in cell-to-cell infection was tested for the ability to resist neutralizing antibodies. The ΔCT mutation increased cell surface staining by neutralizing antibodies, significantly enhanced neutralization of VS-mediated infection, and had reduced or no effect on cell-free infection, depending upon the antibody. Our results suggest that the gp41 CT regulates the exposure of key neutralizing epitopes during cell-to-cell infection and plays an important role in immune evasion. Vaccine strategies should consider immunogens that reflect Env conformations exposed on the infected cell surface to enhance protection against VS-mediated HIV-1 spread. PMID:22553332

  3. HIV-1 Tat exacerbates lipopolysaccharide-induced cytokine release via TLR4 signaling in the enteric nervous system

    PubMed Central

    Guedia, Joy; Brun, Paola; Bhave, Sukhada; Fitting, Sylvia; Kang, Minho; Dewey, William L.; Hauser, Kurt F.; Akbarali, Hamid I.

    2016-01-01

    The loss of gut epithelium integrity leads to translocation of microbes and microbial products resulting in immune activation and drives systemic inflammation in acquired immunodeficiency syndrome (AIDS) patients. Although viral loads in HIV patients are significantly reduced in the post-cART era, inflammation and immune activation persist and can lead to morbidity. Here, we determined the interactive effects of the viral protein HIV-1 Tat and lipopolysaccharide (LPS) on enteric neurons and glia. Bacterial translocation was significantly enhanced in Tat-expressing (Tat+) mice. Exposure to HIV-1 Tat in combination with LPS enhanced the expression and release of the pro-inflammatory cytokines IL-6, IL-1β and TNF-α in the ilea of Tat+ mice and by enteric glia. This coincided with enhanced NF-κB activation in enteric glia that was abrogated in glia from TLR4 knockout mice and by knockdown (siRNA) of MyD88 siRNA in wild type glia. The synergistic effects of Tat and LPS resulted in a reduced rate of colonic propulsion in Tat+ mice treated with LPS. These results show that HIV-1 Tat interacts with the TLR4 receptor to enhance the pro-inflammatory effects of LPS leading to gastrointestinal dysmotility and enhanced immune activation. PMID:27491828

  4. German-austrian recommendations for HIV1-therapy in pregnancy and in HIV1-exposed newborn - update 2008

    PubMed Central

    2009-01-01

    German-Austrian recommendations for HIV1-therapy in pregnancy - Update 2008 Bernd Buchholz (University Medical Centre Mannheim, Pediatric Clinic), Matthias Beichert (Mannheim, Gynecology and Obstetrics Practice), Ulrich Marcus (Robert Koch Institute, Berlin), Thomas Grubert, Andrea Gingelmaier (Gynecology Clinic of the Ludwig Maximilians University of Munich), Dr. med. Annette Haberl (HIV-Department, J. W. Goethe-University Hospital, Frankfurt), Dr. med. Brigitte Schmied (Otto-Wagner Spital, Wien). In Germany during the last years about 200-250 HIV1-infected pregnant women delivered a baby each year, a number that is currently increasing. To determine the HIV-status early in pregnancy voluntary HIV-testing of all pregnant women is recommended in Germany and Austria as part of prenatal care. In those cases, where HIV1-infection was known during pregnancy, since 1995 the rate of vertical transmission of HIV1 was reduced to 1-2%. This low transmission rate has been achieved by the combination of anti-retroviral therapy of pregnant women, caesarean section scheduled before onset of labour, anti-retroviral post exposition prophylaxis in the newborn and refraining from breast-feeding by the HIV1-infected mother. To keep pace with new results in research, approval of new anti-retroviral drugs and changes in the general treatment recommendations for HIV1-infected adults, in 1998, 2001, 2003 and 2005 an interdisciplinary consensus meeting was held. Gynaecologists, infectious disease specialists, paediatricians, pharmacologists, virologists and members of the German AIDS Hilfe (NGO) were participating in this conference to update the prevention strategies. A fifth update became necessary in 2008. The updating process was started in January 2008 and was terminated in September 2008. The guidelines provide new recommendations on the indication and the starting point for HIV-therapy in pregnancies without complications, drugs and drug combinations to be used preferably in these

  5. Characteristics of HIV-1 Discordant Couples Enrolled in a Trial of HSV-2 Suppression to Reduce HIV-1 Transmission: The Partners Study

    PubMed Central

    Lingappa, Jairam R.; Kahle, Erin; Mugo, Nelly; Mujugira, Andrew; Magaret, Amalia; Baeten, Jared; Bukusi, Elizabeth A.; Cohen, Craig R.; Katabira, Elly; Ronald, Allan; Kiarie, James; Farquhar, Carey; Stewart, Grace John; Makhema, Joseph; Essex, M.; Were, Edwin; Fife, Kenneth; deBruyn, Guy; Gray, Glenda; McIntyre, James; Manongi, Rachel; Kapiga, Saidi; Coetzee, David; Allen, Susan; Inambao, Mubiana; Kayitenkore, Kayitesi; Karita, Etienne; Kanweka, William; Delany, Sinead; Rees, Helen; Vwalika, Bellington; Coombs, Robert W.; Morrow, Rhoda; Whittington, William; Corey, Lawrence; Wald, Anna; Celum, Connie

    2009-01-01

    Background The Partners HSV-2/HIV-1 Transmission Study (Partners Study) is a phase III, placebo-controlled trial of daily acyclovir for genital herpes (HSV-2) suppression among HIV-1/HSV-2 co-infected persons to reduce HIV-1 transmission to their HIV-1 susceptible partners, which requires recruitment of HIV-1 serodiscordant heterosexual couples. We describe the baseline characteristics of this cohort. Methods HIV-1 serodiscordant heterosexual couples, in which the HIV-1 infected partner was HSV-2 seropositive, had a CD4 count ≥250 cells/mcL and was not on antiretroviral therapy, were enrolled at 14 sites in East and Southern Africa. Demographic, behavioral, clinical and laboratory characteristics were assessed. Results Of the 3408 HIV-1 serodiscordant couples enrolled, 67% of the HIV-1 infected partners were women. Couples had cohabitated for a median of 5 years (range 2–9) with 28% reporting unprotected sex in the month prior to enrollment. Among HIV-1 susceptible participants, 86% of women and 59% of men were HSV-2 seropositive. Other laboratory-diagnosed sexually transmitted infections were uncommon (<5%), except for Trichomonas vaginalis in 14% of HIV-1 infected women. Median baseline CD4 count for HIV-1 infected participants was 462cells/mcL and median HIV-1 plasma RNA was 4.2 log10 copies/mL. After adjusting for age and African region, correlates of HIV-1 RNA level included male gender (+0.24 log10 copies/mL; p<0.001) and CD4 count (−0.25 and −0.55 log10 copies/mL for CD4 350–499 and >500 relative to <350, respectively, p<0.001). Conclusions The Partners Study successfully enrolled a cohort of 3408 heterosexual HIV-1 serodiscordant couples in Africa at high risk for HIV-1 transmission. Follow-up of this cohort will evaluate the efficacy of acyclovir for HSV-2 suppression in preventing HIV-1 transmission and provide insights into biological and behavioral factors determining heterosexual HIV-1 transmission. Trial Registration ClinicalTrials.gov NCT

  6. NLRX1 Sequesters STING to Negatively Regulate the Interferon Response, Thereby Facilitating the Replication of HIV-1 and DNA Viruses.

    PubMed

    Guo, Haitao; König, Renate; Deng, Meng; Riess, Maximilian; Mo, Jinyao; Zhang, Lu; Petrucelli, Alex; Yoh, Sunnie M; Barefoot, Brice; Samo, Melissa; Sempowski, Gregory D; Zhang, Aiping; Colberg-Poley, Anamaris M; Feng, Hui; Lemon, Stanley M; Liu, Yong; Zhang, Yanping; Wen, Haitao; Zhang, Zhigang; Damania, Blossom; Tsao, Li-Chung; Wang, Qi; Su, Lishan; Duncan, Joseph A; Chanda, Sumit K; Ting, Jenny P-Y

    2016-04-13

    Understanding the negative regulators of antiviral immune responses will be critical for advancing immune-modulated antiviral strategies. NLRX1, an NLR protein that negatively regulates innate immunity, was previously identified in an unbiased siRNA screen as required for HIV infection. We find that NLRX1 depletion results in impaired nuclear import of HIV-1 DNA in human monocytic cells. Additionally, NLRX1 was observed to reduce type-I interferon (IFN-I) and cytokines in response to HIV-1 reverse-transcribed DNA. NLRX1 sequesters the DNA-sensing adaptor STING from interaction with TANK-binding kinase 1 (TBK1), which is a requisite for IFN-1 induction in response to DNA. NLRX1-deficient cells generate an amplified STING-dependent host response to cytosolic DNA, c-di-GMP, cGAMP, HIV-1, and DNA viruses. Accordingly, Nlrx1(-/-) mice infected with DNA viruses exhibit enhanced innate immunity and reduced viral load. Thus, NLRX1 is a negative regulator of the host innate immune response to HIV-1 and DNA viruses.