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Sample records for hiv-1 tat expressing

  1. HIV-1 Tat regulates the expression of the dcw operon and stimulates the proliferation of bacteria.

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    Wei, Jinsong; Zhang, Yumin; Knapp, Pamela E; Zhao, Tianyong

    2016-01-01

    Infections of pathogenic bacteria are very common in acquired immunodeficiency syndrome (AIDS) patients. However, the biological effects of HIV-1 Tat on bacteria are incompletely understood. In this study, HIV-1 Tat was expressed in Escherichia coli and Pseudomonas aeruginosa (PA01) to investigate its biological effects on bacteria. Bacterial cells expressing either HIV-1 Tat1-86 (Tat1-86) or HIV-1 Tat1-72 (Tat1-72) grow significantly faster than those with either only an empty vector or an unrelated control (GFP or Rluc). Supplementation of purified HIV-1 Tat1-86 or Tat1-101 protein into bacterial culture medium stimulated the growth of both E. coli and PA01. The expression profile of certain cell division-associated genes, such as those in the division cell wall (dcw) operon (ftsA, ftsQ, ftsW and ftsZ), yafO and zipA, was altered in HIV-1 Tat1-86 expressing E. coli BL21(DE3). Furthermore, the expression of firefly luciferase (Fluc) reporter gene, when engineered for control by the dcw promoter and terminator, was enhanced by HIV-1 Tat in E. coli, confirming that HIV-1 Tat transcriptionally regulates the expression of the dcw operon. The finding that HIV-1 Tat stimulates bacterial growth whether it is produced intracellularly or applied extracellularly may have relevance for HIV patients who are highly susceptible to opportunistic bacterial infections. Contents category: Viruses -Retroviruses. The GenBank accession number for the sequence of HIV-1 Tat1-86 is AF324439.1.

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

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    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.

  3. In vitro nuclear interactome of the HIV-1 Tat protein.

    LENUS (Irish Health Repository)

    Gautier, Virginie W

    2009-01-01

    BACKGROUND: One facet of the complexity underlying the biology of HIV-1 resides not only in its limited number of viral proteins, but in the extensive repertoire of cellular proteins they interact with and their higher-order assembly. HIV-1 encodes the regulatory protein Tat (86-101aa), which is essential for HIV-1 replication and primarily orchestrates HIV-1 provirus transcriptional regulation. Previous studies have demonstrated that Tat function is highly dependent on specific interactions with a range of cellular proteins. However they can only partially account for the intricate molecular mechanisms underlying the dynamics of proviral gene expression. To obtain a comprehensive nuclear interaction map of Tat in T-cells, we have designed a proteomic strategy based on affinity chromatography coupled with mass spectrometry. RESULTS: Our approach resulted in the identification of a total of 183 candidates as Tat nuclear partners, 90% of which have not been previously characterised. Subsequently we applied in silico analysis, to validate and characterise our dataset which revealed that the Tat nuclear interactome exhibits unique signature(s). First, motif composition analysis highlighted that our dataset is enriched for domains mediating protein, RNA and DNA interactions, and helicase and ATPase activities. Secondly, functional classification and network reconstruction clearly depicted Tat as a polyvalent protein adaptor and positioned Tat at the nexus of a densely interconnected interaction network involved in a range of biological processes which included gene expression regulation, RNA biogenesis, chromatin structure, chromosome organisation, DNA replication and nuclear architecture. CONCLUSION: We have completed the in vitro Tat nuclear interactome and have highlighted its modular network properties and particularly those involved in the coordination of gene expression by Tat. Ultimately, the highly specialised set of molecular interactions identified will

  4. HIV-1 Tat interacts with LIS1 protein

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    Turner Willie

    2005-02-01

    Full Text Available Abstract Background HIV-1 Tat activates transcription of HIV-1 viral genes by inducing phosphorylation of the C-terminal domain (CTD of RNA polymerase II (RNAPII. Tat can also disturb cellular metabolism by inhibiting proliferation of antigen-specific T lymphocytes and by inducing cellular apoptosis. Tat-induced apoptosis of T-cells is attributed, in part, to the distortion of microtubules polymerization. LIS1 is a microtubule-associated protein that facilitates microtubule polymerization. Results We identified here LIS1 as a Tat-interacting protein during extensive biochemical fractionation of T-cell extracts. We found several proteins to co-purify with a Tat-associated RNAPII CTD kinase activity including LIS1, CDK7, cyclin H, and MAT1. Tat interacted with LIS1 but not with CDK7, cyclin H or MAT1 in vitro. LIS1 also co-immunoprecipitated with Tat expressed in HeLa cells. Further, LIS1 interacted with Tat in a yeast two-hybrid system. Conclusion Our results indicate that Tat interacts with LIS1 in vitro and in vivo and that this interaction might contribute to the effect of Tat on microtubule formation.

  5. Potent inhibition of HIV-1 replication by a Tat mutant.

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    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.

  6. Potent inhibition of HIV-1 replication by a Tat mutant.

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    Luke W Meredith

    Full Text Available 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.

  7. Selective Vulnerability of Striatal D2 versus D1 Dopamine Receptor-Expressing Medium Spiny Neurons in HIV-1 Tat Transgenic Male Mice.

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    Schier, Christina J; Marks, William D; Paris, Jason J; Barbour, Aaron J; McLane, Virginia D; Maragos, William F; McQuiston, A Rory; Knapp, Pamela E; Hauser, Kurt F

    2017-06-07

    Despite marked regional differences in HIV susceptibility within the CNS, there has been surprisingly little exploration into the differential vulnerability among neuron types and the circuits they underlie. The dorsal striatum is especially susceptible, harboring high viral loads and displaying marked neuropathology, with motor impairment a frequent manifestation of chronic infection. However, little is known about the response of individual striatal neuron types to HIV or how this disrupts function. Therefore, we investigated the morphological and electrophysiological effects of HIV-1 trans-activator of transcription (Tat) in dopamine subtype 1 (D1) and dopamine subtype 2 (D2) receptor-expressing striatal medium spiny neurons (MSNs) by breeding transgenic Tat-expressing mice to Drd1a-tdTomato- or Drd2-eGFP-reporter mice. An additional goal was to examine neuronal vulnerability early during the degenerative process to gain insight into key events underlying the neuropathogenesis. In D2 MSNs, exposure to HIV-1 Tat reduced dendritic spine density significantly, increased dendritic damage (characterized by swellings/varicosities), and dysregulated neuronal excitability (decreased firing at 200-300 pA and increased firing rates at 450 pA), whereas insignificant morphologic and electrophysiological consequences were observed in Tat-exposed D1 MSNs. These changes were concomitant with an increased anxiety-like behavioral profile (lower latencies to enter a dark chamber in a light-dark transition task, a greater frequency of light-dark transitions, and reduced rearing time in an open field), whereas locomotor behavior was unaffected by 2 weeks of Tat induction. Our findings suggest that D2 MSNs and a specific subset of neural circuits within the dorsal striatum are preferentially vulnerable to HIV-1.SIGNIFICANCE STATEMENT Despite combination antiretroviral therapy (cART), neurocognitive disorders afflict 30-50% of HIV-infected individuals and synaptodendritic injury

  8. Inhibition of both HIV-1 reverse transcription and gene expression by a cyclic peptide that binds the Tat-transactivating response element (TAR RNA.

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    Matthew S Lalonde

    2011-05-01

    Full Text Available The RNA response element TAR plays a critical role in HIV replication by providing a binding site for the recruitment of the viral transactivator protein Tat. Using a structure-guided approach, we have developed a series of conformationally-constrained cyclic peptides that act as structural mimics of the Tat RNA binding region and block Tat-TAR interactions at nanomolar concentrations in vitro. Here we show that these compounds block Tat-dependent transcription in cell-free systems and in cell-based reporter assays. The compounds are also cell permeable, have low toxicity, and inhibit replication of diverse HIV-1 strains, including both CXCR4-tropic and CCR5-tropic primary HIV-1 isolates of the divergent subtypes A, B, C, D and CRF01_AE. In human peripheral blood mononuclear cells, the cyclic peptidomimetic L50 exhibited an IC(50 ∼250 nM. Surprisingly, inhibition of LTR-driven HIV-1 transcription could not account for the full antiviral activity. Timed drug-addition experiments revealed that L-50 has a bi-phasic inhibition curve with the first phase occurring after HIV-1 entry into the host cell and during the initiation of HIV-1 reverse transcription. The second phase coincides with inhibition of HIV-1 transcription. Reconstituted reverse transcription assays confirm that HIV-1 (- strand strong stop DNA synthesis is blocked by L50-TAR RNA interactions in-vitro. These findings are consistent with genetic evidence that TAR plays critical roles both during reverse transcription and during HIV gene expression. Our results suggest that antiviral drugs targeting TAR RNA might be highly effective due to a dual inhibitory mechanism.

  9. Expression of the IL-7 receptor alpha-chain is down regulated on the surface of CD4 T-cells by the HIV-1 Tat protein.

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    Denny McLaughlin

    Full Text Available HIV infection elicits defects in CD4 T-cell homeostasis in both a quantitative and qualitative manner. Interleukin-7 (IL-7 is essential to T-cell homeostasis and several groups have shown reduced levels of the IL-7 receptor alpha-chain (CD127 on both CD4 and CD8 T-cells in viremic HIV+ patients. We have shown previously that soluble HIV Tat protein specifically down regulates cell surface expression of CD127 on human CD8 T-cells in a paracrine fashion. The effects of Tat on CD127 expression in CD4 T-cells has yet to be described. To explore this effect, CD4 T-cells were isolated from healthy individuals and expression levels of CD127 were examined on cells incubated in media alone or treated with Tat protein. We show here that, similar to CD8 T-cells, the HIV-1 Tat protein specifically down regulates CD127 on primary human CD4 T-cells and directs the receptor to the proteasome for degradation. Down regulation of CD127 in response to Tat was seen on both memory and naive CD4 T-cell subsets and was blocked using either heparin or anti-Tat antibodies. Tat did not induce apoptosis in cultured primary CD4 T-cells over 72 hours as determined by Annexin V and PI staining. Pre-incubation of CD4 T-cells with HIV-1 Tat protein did however reduce the ability of IL-7 to up regulate Bcl-2 expression. Similar to exogenous Tat, endogenously expressed HIV Tat protein also suppressed CD127 expression on primary CD4 T-cells. In view of the important role IL-7 plays in lymphocyte proliferation, homeostasis and survival, down regulation of CD127 by Tat likely plays a central role in immune dysregulation and CD4 T-cell decline. Understanding this effect could lead to new approaches to mitigate the CD4 T-cell loss evident in HIV infection.

  10. Role of endolysosomes in HIV-1 Tat-induced neurotoxicity

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    Liang Hui

    2012-06-01

    Full Text Available Combined anti-retroviral therapeutic drugs effectively increase the lifespan of HIV-1-infected individuals who then have a higher prevalence of HAND (HIV-1 associated neurocognitive disorder. Soluble factors including HIV-1 proteins released from HIV-1-infected cells have been implicated in the pathogenesis of HAND, and particular attention has been paid to the HIV-1 Tat (transactivator of transcription protein because of its ability to directly excite neurons and cause neuronal cell death. Since HIV-1 Tat enters cells by receptor-mediated endocytosis and since endolysosomes play an important role in neuronal cell life and death, we tested here the hypothesis that HIV-1 Tat neurotoxicity is associated with changes in the endolysosome structure and function and also autophagy. Following the treatment of primary cultured rat hippocampal neurons with HIV-1 Tat or as controls mutant-Tat or PBS, neuronal viability was determined using a triple staining method. Preceding observations of HIV-1 Tat-induced neuronal cell death, we observed statistically significant changes in the structure and membrane integrity of endolysosomes, endolysosome pH and autophagy. As early as 24 h after HIV-1 Tat was applied to neurons, HIV-1 Tat accumulated in endolysosomes, endolysosome morphology was affected and their size increased, endolysosome membrane integrity was disrupted, endolysosome pH increased, specific activities of endolysosome enzymes decreased and autophagy was inhibited, as indicated by the significant changes in three markers for autophagy. In contrast, statistically significant levels of HIV-1 Tat-induced neuronal cell death were observed only after 48 h of HIV-1 Tat treatment. Our findings suggest that endolysosomes are involved in HIV-1 Tat-induced neurotoxicity and may represent a target for therapeutic intervention against HAND.

  11. Role of Endolysosomes in HIV-1 Tat-Induced Neurotoxicity

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    Liang Hui

    2012-05-01

    Full Text Available Combined anti-retroviral therapeutic drugs effectively increase the lifespan of HIV-1-infected individuals who then have a higher prevalence of HAND (HIV-1 associated neurocognitive disorder. Soluble factors including HIV-1 proteins released from HIV-1-infected cells have been implicated in the pathogenesis of HAND, and particular attention has been paid to the HIV-1 Tat (transactivator of transcription protein because of its ability to directly excite neurons and cause neuronal cell death. Since HIV-1 Tat enters cells by receptor-mediated endocytosis and since endolysosomes play an important role in neuronal cell life and death, we tested here the hypothesis that HIV-1 Tat neurotoxicity is associated with changes in the endolysosome structure and function and also autophagy. Following the treatment of primary cultured rat hippocampal neurons with HIV-1 Tat or as controls mutant-Tat or PBS, neuronal viability was determined using a triple staining method. Preceding observations of HIV-1 Tat-induced neuronal cell death, we observed statistically significant changes in the structure and membrane integrity of endolysosomes, endolysosome pH and autophagy. As early as 24 h after HIV-1 Tat was applied to neurons, HIV-1 Tat accumulated in endolysosomes, endolysosome morphology was affected and their size increased, endolysosome membrane integrity was disrupted, endolysosome pH increased, specific activities of endolysosome enzymes decreased and autophagy was inhibited, as indicated by the significant changes in three markers for autophagy. In contrast, statistically significant levels of HIV-1 Tat-induced neuronal cell death were observed only after 48 h of HIV-1 Tat treatment. Our findings suggest that endolysosomes are involved in HIV-1 Tat-induced neurotoxicity and may represent a target for therapeutic intervention against HAND.

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

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    Kusano, Shuichi, E-mail: skusano@m2.kufm.kagoshima-u.ac.jp; 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.

  13. Pentosan polysulfate as an inhibitor of extracellular HIV-1 Tat.

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    Rusnati, M; Urbinati, C; Caputo, A; Possati, L; Lortat-Jacob, H; Giacca, M; Ribatti, D; Presta, M

    2001-06-22

    HIV-1 Tat protein, released from HIV-infected cells, may act as a pleiotropic heparin-binding growth factor. From this observation, extracellular Tat has been implicated in the pathogenesis of AIDS and of AIDS-associated pathologies. Here we demonstrate that the heparin analog pentosan polysulfate (PPS) inhibits the interaction of glutathione S-transferase (GST)-Tat protein with heparin immobilized to a BIAcore sensor chip. Competition experiments showed that Tat-PPS interaction occurs with high affinity (K(d) = 9.0 nm). Also, GST.Tat prevents the binding of [(3)H]heparin to GST.Tat immobilized to glutathione-agarose beads. In vitro, PPS inhibits GST.Tat internalization and, consequently, HIV-1 long terminal repeat transactivation in HL3T1 cells. Also, PPS inhibits cell surface interaction and mitogenic activity of GST.Tat in murine adenocarcinoma T53 Tat-less cells. In all assays, PPS exerts its Tat antagonist activity with an ID(50) equal to approximately 1.0 nm. In vivo, PPS inhibits the neovascularization induced by GST.Tat or by Tat-overexpressing T53 cells in the chick embryo chorioallantoic membrane. In conclusion, PPS binds Tat protein and inhibits its cell surface interaction, internalization, and biological activity in vitro and in vivo. PPS may represent a prototypic molecule for the development of novel Tat antagonists with therapeutic implications in AIDS and AIDS-associated pathologies, including Kaposi's sarcoma.

  14. Tat RNA silencing suppressor activity contributes to perturbation of lymphocyte miRNA by HIV-1

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    Yu Lianbo

    2011-05-01

    Full Text Available Abstract Background MicroRNA (miRNA-mediated RNA silencing is integral to virtually every cellular process including cell cycle progression and response to virus infection. The interplay between RNA silencing and HIV-1 is multifaceted, and accumulating evidence posits a strike-counterstrike interface that alters the cellular environment to favor virus replication. For instance, miRNA-mediated RNA silencing of HIV-1 translation is antagonized by HIV-1 Tat RNA silencing suppressor activity. The activity of HIV-1 accessory proteins Vpr/Vif delays cell cycle progression, which is a process prominently modulated by miRNA. The expression profile of cellular miRNA is altered by HIV-1 infection in both cultured cells and clinical samples. The open question stands of what, if any, is the contribution of Tat RNA silencing suppressor activity or Vpr/Vif activity to the perturbation of cellular miRNA by HIV-1. Results Herein, we compared the perturbation of miRNA expression profiles of lymphocytes infected with HIV-1NL4-3 or derivative strains that are deficient in Tat RNA silencing suppressor activity (Tat K51A substitution or ablated of the vpr/vif open reading frames. Microarrays recapitulated the perturbation of the cellular miRNA profile by HIV-1 infection. The miRNA expression trends overlapped ~50% with published microarray results on clinical samples from HIV-1 infected patients. Moreover, the number of miRNA perturbed by HIV-1 was largely similar despite ablation of Tat RSS activity and Vpr/Vif; however, the Tat RSS mutation lessened HIV-1 downregulation of twenty-two miRNAs. Conclusions Our study identified miRNA expression changes attributable to Tat RSS activity in HIV-1NL4-3. The results accomplish a necessary step in the process to understand the interface of HIV-1 with host RNA silencing activity. The overlap in miRNA expression trends observed between HIV-1 infected CEMx174 lymphocytes and primary cells supports the utility of cultured

  15. Human DDX3 interacts with the HIV-1 Tat protein to facilitate viral mRNA translation.

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    Ming-Chih Lai

    Full Text Available Nuclear export and translation of intron-containing viral mRNAs are required for HIV-1 gene expression and replication. In this report, we provide evidence to show that DDX3 regulates the translation of HIV-1 mRNAs. We found that knockdown of DDX3 expression effectively inhibited HIV-1 production. Translation of HIV-1 early regulatory proteins, Tat and rev, was impaired in DDX3-depleted cells. All HIV-1 transcripts share a highly structured 5' untranslated region (UTR with inhibitory elements on translation of viral mRNAs, yet DDX3 promoted translation of reporter mRNAs containing the HIV-1 5' UTR, especially with the transactivation response (TAR hairpin. Interestingly, DDX3 directly interacts with HIV-1 Tat, a well-characterized transcriptional activator bound to the TAR hairpin. HIV-1 Tat is partially targeted to cytoplasmic stress granules upon DDX3 overexpression or cell stress conditions, suggesting a potential role of Tat/DDX3 complex in translation. We further demonstrated that HIV-1 Tat remains associated with translating mRNAs and facilitates translation of mRNAs containing the HIV-1 5' UTR. Taken together, these findings indicate that DDX3 is recruited to the TAR hairpin by interaction with viral Tat to facilitate HIV-1 mRNA translation.

  16. Human DDX3 interacts with the HIV-1 Tat protein to facilitate viral mRNA translation.

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    Lai, Ming-Chih; Wang, Shainn-Wei; Cheng, Lie; Tarn, Woan-Yuh; Tsai, Shaw-Jenq; Sun, H Sunny

    2013-01-01

    Nuclear export and translation of intron-containing viral mRNAs are required for HIV-1 gene expression and replication. In this report, we provide evidence to show that DDX3 regulates the translation of HIV-1 mRNAs. We found that knockdown of DDX3 expression effectively inhibited HIV-1 production. Translation of HIV-1 early regulatory proteins, Tat and rev, was impaired in DDX3-depleted cells. All HIV-1 transcripts share a highly structured 5' untranslated region (UTR) with inhibitory elements on translation of viral mRNAs, yet DDX3 promoted translation of reporter mRNAs containing the HIV-1 5' UTR, especially with the transactivation response (TAR) hairpin. Interestingly, DDX3 directly interacts with HIV-1 Tat, a well-characterized transcriptional activator bound to the TAR hairpin. HIV-1 Tat is partially targeted to cytoplasmic stress granules upon DDX3 overexpression or cell stress conditions, suggesting a potential role of Tat/DDX3 complex in translation. We further demonstrated that HIV-1 Tat remains associated with translating mRNAs and facilitates translation of mRNAs containing the HIV-1 5' UTR. Taken together, these findings indicate that DDX3 is recruited to the TAR hairpin by interaction with viral Tat to facilitate HIV-1 mRNA translation.

  17. Intersubtype Genetic Variation of HIV-1 Tat Exon 1.

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    Roy, Chandra Nath; Khandaker, Irona; Oshitani, Hitoshi

    2015-06-01

    HIV-1 Tat is a regulatory protein that plays a pivotal role in viral transcription and replication. Our study aims to investigate the genetic variation of Tat exon 1 in all subtypes of HIV-1: A, B, C, D, F, G, H, J, and K. We performed phylogenetic, mutation, and selection pressure analyses on a total of 1,179 sequences of different subtypes of HIV-1 Tat obtained from the Los Alamos National Laboratory (LANL). The mean nucleotide divergences (%) among the analyzed sequences of subtypes A, B, C, D, F, G, H, J, and K were 88, 89, 90, 88, 86, 89, 88, 97, and 97, respectively. We revealed that subtype B evolved relatively faster than other subtypes. The second and fifth domains were found comparatively more variable among all subtypes. Site-by-site tests of positive selection revealed that several positions in all subtypes were under significant positive selection. Positively selected sites were found in the acidic domain at positions 3, 4, and 19, in the cysteine-rich domains at positions 24, 29, 32, and 36, in the core domain at position 40, and in the basic domain for the rest of the positions for all subtypes. Positions 58 and 68 in the basic domain were positively selected in subtypes A, B, C and B, C, F, respectively. We also observed high variability within positively selected sites in amino acid positions. Our study findings on HIV-1 Tat genetic variability may contribute to a better understanding of HIV-1 evolution as well as to the development of effective Tat-targeted therapeutics and vaccines.

  18. HIV-1 Tat Inhibits Autotaxin Lysophospholipase D Activity and Modulates Oligodendrocyte Differentiation

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    Wheeler, Natalie A.; Fuss, Babette; Knapp, Pamela E.

    2016-01-01

    White matter injury has been frequently reported in HIV+ patients. Previous studies showed that HIV-1 Tat (transactivator of transcription), a viral protein that is produced and secreted by HIV-infected cells, is toxic to young, immature oligodendrocytes (OLGs). Adding Tat to the culture medium reduced the viability of immature OLGs, and the surviving OLGs exhibited reduced process networks. OLGs produce and secrete autotaxin (ATX), an ecto-enzyme containing a lysophospholipase D (lysoPLD) activity that converts lysophosphatidylcholine (LPC) to lysophosphatidic acid (LPA), a lipid signaling molecule that stimulates OLG differentiation. We hypothesized that Tat affects OLG development by interfering with the ATX-LPA signaling pathway. Our data show that Tat treatment leads to changes in the expression of OLG differentiation genes and the area of OLG process networks, both of which can be rescued by LPA. Tat-treated OLGs showed no change in LPA receptor expression but significantly decreased extracellular ATX levels and lysoPLD activity. In Tat transgenic mice, expression of Tat in vivo leads to decreased OLG ATX secretion. Furthermore, co-immunoprecipitation experiments revealed a potential physical interaction between Tat and ATX. Together, these data strongly suggest two functional implications of Tat blocking ATX’s lysoPLD activity. On one hand, it attenuates OLG differentiation, and on the other hand it interferes with the protective effects of LPA on OLG process morphology. PMID:27659560

  19. Extracellular HIV Tat and Tat cysteine rich peptide increase CCR5 expression in monocytes

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    ZHENG Lin; YANG Yi-da; LU Guo-cai; SALVATO Maria S

    2005-01-01

    In our previous work we reported that HIV Tat and 6 cysteine rich peptides of Tat induce tumor necrosis factor-related apoptosis-induced ligand (TRAIL) in human monocytes (Yang et al., 2003). Here our results showed that HIV Tat and Tat cysteine rich peptide increase CCR5 expression in human monocytes, and this activity is inhibited by rabbit anti-Tat. Boiled Tat does not increase CCR5 expression in monocytes. These results provide insight into a new mechanism by which HIV Tat plays a key role in the pathogenesis of HIV-1 infection.

  20. Intracerebroventricular administration of HIV-1 Tat induces brain cytokine and indoleamine 2,3-dioxygenase expression: a possible mechanism for AIDS comorbid depression.

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    Lawson, Marcus A; Kelley, Keith W; Dantzer, Robert

    2011-11-01

    Human immunodeficiency virus (HIV) remains a major public health concern despite a large education effort during the past 25 years. A persistent problem with HIV infection is the high comorbity rate of clinical depression. We previously established that increasing proinflammatory cytokines within the brain of mice induces sickness that can culminate in depressive-like behavior. Here we investigated the role of the HIV transactivator of transcription (Tat) protein in activation of brain cytokine signaling and subsequent induction of depressive-like behavior in a murine model. Adult Balb/c mice were administered a single intracerebroventricular (ICV) injection of Tat (40 ng). Social investigation of a novel juvenile was measured at 2, 4, 8 and 24 h post-treatment. Mice treated with Tat did not display signs of sickness, as measured by either decreased social investigation or loss of body weight. At 24 h post-injection, mice were subjected to the forced swim test (FST). ICV administration of Tat to Balb/c mice increased immobility in the FST at 24 h post injection. A different strain of mice, C57BL/6J, responded similarly in the FST. Furthermore, adult C57BL/6J mice injected with Tat and tested in a two-bottle 1% sucrose preference test displayed reduced preference for sucrose during the 24 h post-injection period. Subsequently, brain tissues from Tat-treated and control C57BL/6J mice were collected at 4 and 24 h post injection. CNS tissue from Tat-treated mice had increased expression of IL-1β, TNF-α, IL-6, and IDO mRNAs at 4 h post injection. These data demonstrate that a single exposure to Tat in the brain is sufficient to induce brain cytokine signaling that culminates in depressive-like behavior. The results reveal a potential role for Tat in the development of comorbid depression in HIV-infected individuals.

  1. Celastrol ameliorates HIV-1 Tat-induced inflammatory responses via NF-kappaB and AP-1 inhibition and heme oxygenase-1 induction in astrocytes

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    Youn, Gi Soo; Kwon, Dong-Joo; Ju, Sung Mi [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Rhim, Hyangshuk [Department of Biomedical Sciences, Department of Medical Life Sciences, College of Medicine, the Catholic University of Korea, Seoul 137-701 (Korea, Republic of); Bae, Yong Soo [Department of Biological Science, College of Natural Sciences, Sungkyunkwan University, Suwon 440-746 (Korea, Republic of); Choi, Soo Young [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of); Park, Jinseu, E-mail: jinpark@hallym.ac.kr [Department of Biomedical Science and Research Institute for Bioscience and Biotechnology, Hallym University, Chunchon 200-702 (Korea, Republic of)

    2014-10-01

    HIV-1 Tat causes extensive neuroinflammation that may progress to AIDS-related encephalitis and dementia. Celastrol possesses various biological activities such as anti-oxidant, anti-tumor, and anti-inflammatory activities. In this study, we investigated the modulatory effects of celastrol on HIV-1 Tat-induced inflammatory responses and the molecular mechanisms underlying its action in astrocytes. Pre-treatment of CRT-MG human astroglioma cells with celastrol significantly inhibited HIV-1 Tat-induced expression of ICAM-1/VCAM-1 and subsequent monocyte adhesiveness in CRT-MG cells. In addition, celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory chemokines, such as CXCL10, IL-8, and MCP-1. Celastrol decreased HIV-1 Tat-induced activation of JNK MAPK, AP-1, and NF-κB. Furthermore, celastrol induced mRNA and protein expression of HO-1 as well as Nrf2 activation. Blockage of HO-1 expression using siRNA reversed the inhibitory effect of celastrol on HIV-1 Tat-induced inflammatory responses. These results suggest that celastrol has regulatory effects on HIV-1 Tat-induced inflammatory responses by blocking the JNK MAPK-AP-1/NF-κB signaling pathways and inducing HO-1 expression in astrocytes. - Highlights: • Celastrol suppressed HIV-1 Tat-induced expression of pro-inflammatory genes. • Celastrol inhibited HIV-1 Tat -induced activation of JNK MAPK. • Celastrol inhibited HIV-1 Tat-induced activation of both NF-κB and AP-1. • Celastrol inhibited HIV-1 Tat-induced inflammatory responses via HO-1 induction.

  2. HIV-1 Tat protein increases microglial outward K(+ current and resultant neurotoxic activity.

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    Jianuo Liu

    Full Text Available 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-Phenoxybutoxypsoralen, 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.

  3. DDX3 RNA helicase is required for HIV-1 Tat function.

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    Yasuda-Inoue, Mariko; Kuroki, Misao; Ariumi, Yasuo

    2013-11-22

    Host RNA helicase has been involved in human immunodeficiency virus type 1 (HIV-1) replication, since HIV-1 does not encode an RNA helicase. Indeed, DDX1 and DDX3 DEAD-box RNA helicases are known to be required for efficient HIV-1 Rev-dependent RNA export. However, it remains unclear whether DDX RNA helicases modulate the HIV-1 Tat function. In this study, we demonstrate, for the first time, that DDX3 is required for the HIV-1 Tat function. Notably, DDX3 colocalized and interacted with HIV-1 Tat in cytoplasmic foci. Indeed, DDX3 localized in the cytoplasmic foci P-bodies or stress granules under stress condition after the treatment with arsenite. Importantly, only DDX3 enhanced the Tat function, while various distinct DEAD-box RNA helicases including DDX1, DDX3, DDX5, DDX17, DDX21, and DDX56, stimulated the HIV-1 Rev-dependent RNA export function, indicating a specific role of DDX3 in Tat function. Indeed, the ATPase-dependent RNA helicase activity of DDX3 seemed to be required for the Tat function as well as the colocalization with Tat. Furthermore, the combination of DDX3 with other distinct DDX RNA helicases cooperated to stimulate the Rev but not Tat function. Thus, DDX3 seems to interact with the HIV-1 Tat and facilitate the Tat function.

  4. Shutdown of HIV-1 Transcription in T Cells by Nullbasic, a Mutant Tat Protein

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    Hongping Jin

    2016-07-01

    Full Text Available Nullbasic is a derivative of the HIV-1 transactivator of transcription (Tat protein that strongly inhibits HIV-1 replication in lymphocytes. Here we show that lentiviral vectors that constitutively express a Nullbasic-ZsGreen1 (NB-ZSG1 fusion protein by the eEF1α promoter led to robust long-term inhibition of HIV-1 replication in Jurkat cells. Although Jurkat-NB-ZSG1 cells were infected by HIV-1, no virus production could be detected and addition of phorbol ester 12-myristate 13-acetate (PMA and JQ1 had no effect, while suberanilohydroxamic acid (SAHA modestly stimulated virus production but at levels 300-fold lower than those seen in HIV-1-infected Jurkat-ZSG1 cells. Virus replication was not recovered by coculture of HIV-1-infected Jurkat-NB-ZSG1 cells with uninfected Jurkat cells. Latently infected Jurkat latent 6.3 and ACH2 cells treated with latency-reversing agents produced measurable viral capsid (CA, but little or none was made when they expressed NB-ZSG1. When Jurkat cells chronically infected with HIV-1 were transduced with lentiviral virus-like particles conveying NB-ZSG1, a >3-log reduction in CA production was observed. Addition of PMA increased virus CA production but at levels 500-fold lower than those seen in nontransduced Jurkat cells. Transcriptome sequencing analysis confirmed that HIV-1 mRNA was strongly inhibited by NB-ZSG1 but indicated that full-length viral mRNA was made. Analysis of HIV-1-infected Jurkat cells expressing NB-ZSG1 by chromatin immunoprecipitation assays indicated that recruitment of RNA polymerase II (RNAPII and histone 3 lysine 9 acetylation were inhibited. The reduction of HIV-1 promoter-associated RNAPII and epigenetic changes in viral nucleosomes indicate that Nullbasic can inhibit HIV-1 replication by enforcing viral silencing in cells.

  5. Crystal structure of HIV-1 Tat complexed with human P-TEFb

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    Tahirov, Tahir H.; Babayeva, Nigar D.; Varzavand, Katayoun; Cooper, Jeffrey J.; Sedore, Stanley C.; Price, David H. (Nebraska-Med); (Iowa)

    2010-08-23

    Regulation of the expression of the human immunodeficiency virus (HIV) genome is accomplished in large part by controlling transcription elongation. The viral protein Tat hijacks the host cell's RNA polymerase II elongation control machinery through interaction with the positive transcription elongation factor, P-TEFb, and directs the factor to promote productive elongation of HIV mRNA. Here we describe the crystal structure of the Tat-P-TEFb complex containing HIV-1 Tat, human Cdk9 (also known as CDK9), and human cyclin T1 (also known as CCNT1). Tat adopts a structure complementary to the surface of P-TEFb and makes extensive contacts, mainly with the cyclin T1 subunit of P-TEFb, but also with the T-loop of the Cdk9 subunit. The structure provides a plausible explanation for the tolerance of Tat to sequence variations at certain sites. Importantly, Tat induces significant conformational changes in P-TEFb. This finding lays a foundation for the design of compounds that would specifically inhibit the Tat-P-TEFb complex and block HIV replication.

  6. HIV-1 tat and rev upregulates osteoclast bone resorption

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    Nicholas Chew

    2014-11-01

    Full Text Available Introduction: Disruption in bone homeostasis with increased osteoclastic resorption may lead to osteoporosis. HIV tat has been found to increase differentiation of precursor cells into osteoclast (OC (1. Presence of soluble HIV proteins in virally suppressed HIV patients on ART may drive a bone resorption phenotype. We investigated the role of soluble HIV proteins (tat, gp120 Mn and Bal, rev and p55-gag on osteoclastogenesis and OC resorptive capacity. Methods: Mouse monocyte RAW 264.7 cells were cultured in vitro and induced to differentiate into OCs with 50 ng/mL RANKL and 25 ng/mL mCSF. Medium was supplemented with 100 ng/mL of recombinant HIV tat, gp120 (Mn and Bal, rev, nef and p55-gag, respectively, with zolendronate as negative control. Differentiated OCs were stained for TRAP and counted. OC resorption function was examined by culturing differentiated OCs (in the presence of respective HIV proteins on dentin-coated plates and examining the following (i sealing zone formation, (ii volume of resorption pits and (iii area of resorption pits per field using confocal microscopy. Expression of OC specific genes including NFATc1 and cathepsin K was investigated by qPCR. Reactive oxygen species (ROS production is essential in RANKL-induced OC differentiation (2,3; effect of these proteins on ROS production was assessed using the fluorescent H2DCFH-DA. Mean fluorescence intensity was then measured by flow cytometry. TNFα production by OC precursors when incubated with tat and rev was measured by ELISA. Results: Tat and rev treatment was associated with increased OC formation by 70 and 26%, respectively (p<0.01, relative to control, while zolendronate significantly inhibited OC formation by 75%. Gp120 Mn and Bal, nef and p55-gag treatment had no effect on OC differentiation. Interestingly, neither tat nor rev treatment caused significant increases in sealing zone formation but increased dentin resorption pit area by 28 and 19%, respectively, and

  7. Transactivation and signaling functions of Tat are not correlated: biological and immunological characterization of HIV-1 subtype-C Tat protein

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    Siddappa, Nagadenahalli Byrareddy; Venkatramanan, Mohanram; Venkatesh, Prasanna; Janki, Mohanbabu Vijayamma; Jayasuryan, Narayana; Desai, Anita; Ravi, Vasanthapuram; Ranga, Udaykumar

    2006-01-01

    Background Of the diverse subtypes of Human Immunodeficiency Virus Type-1 (HIV-1), subtype-C strains cause a large majority of infections worldwide. The reasons for the global dominance of HIV-1 subtype-C infections are not completely understood. Tat, being critical for viral infectivity and pathogenesis, may differentially modulate pathogenic properties of the viral subtypes. Biochemical studies on Tat are hampered by the limitations of the current purification protocols. Tat purified using standard protocols often is competent for transactivation activity but defective for a variety of other biological functions. Keeping this limitation in view, we developed an efficient protein purification strategy for Tat. Results Tat proteins obtained using the novel strategy described here were free of contaminants and retained biological functions as evaluated in a range of assays including the induction of cytokines, upregulation of chemokine coreceptor, transactivation of the viral promoter and rescue of a Tat-defective virus. Given the highly unstable nature of Tat, we evaluated the effect of the storage conditions on the biological function of Tat following purification. Tat stored in a lyophilized form retained complete biological activity regardless of the storage temperature. To understand if variations in the primary structure of Tat could influence the secondary structure of the protein and consequently its biological functions, we determined the CD spectra of subtype-C and -B Tat proteins. We demonstrate that subtype-C Tat may have a relatively higher ordered structure and be less flexible than subtype-B Tat. We show that subtype-C Tat as a protein, but not as a DNA expression vector, was consistently inferior to subtype-B Tat in a variety of biological assays. Furthermore, using ELISA, we evaluated the anti-Tat antibody titers in a large number of primary clinical samples (n = 200) collected from all four southern Indian states. Our analysis of the Indian

  8. PKCtheta and HIV-1 transcriptional regulator Tat co-exist at the LTR promoter in CD4+ T cells

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    Maria Rosa eLopez-Huertas

    2016-02-01

    Full Text Available PKCtheta is essential for the activation of CD4+ T cells. Upon TCR/CD28 stimulation, PKCtheta is phosphorylated and migrates to the immunological synapse, inducing the activation of cellular transcription factors such as NF-kB and kinases as ERK that are critical for HIV-1 replication. We previously demonstrated that PKCtheta is also necessary for HIV-1 replication but the precise mechanism is unknown. Efficient HIV-1 transcription and elongation is absolutely dependent on the synergy between NF-kB and the viral regulator Tat. Tat exerts its function by binding a RNA stem-loop structure proximal to the viral mRNA cap site termed TAR. Besides, due to its effect on cellular metabolic pathways, Tat causes profound changes in infected CD4+ T cells such as the activation of NF-kB and ERK. We hypothesized that the aberrant up-regulation of Tat-mediated activation of NF-kB and ERK occurred through PKCtheta signaling. In fact, Jurkat TetOff cells with stable and doxycycline-repressible expression of Tat (Jurkat-Tat expressed high levels of mRNA for PKCtheta. In these cells, PKCtheta located at the plasma membrane was phosphorylated at T538 residue in undivided cells, in the absence of stimulation. Treatment with doxycycline inhibited PKCtheta phosphorylation in Jurkat-Tat, suggesting that Tat expression was directly related to the activation of PKCtheta. Both NF-kB and Ras/Raf/MEK/ERK signaling pathway were significantly activated in Jurkat-Tat cells, and this correlated with high transactivation of HIV-1 LTR promoter. RNA interference for PKCtheta inhibited NF-kB and ERK activity, as well as LTR-mediated transactivation even in the presence of Tat. In addition to Tat-mediated activation of PKCtheta in the cytosol, we demonstrated by sequential ChIP that Tat and PKCtheta coexisted in the same complex bound at the HIV-1 LTR promoter, specifically at the region containing TAR loop. In conclusion, PKCtheta-Tat interaction seemed to be essential for HIV-1

  9. Impact of Genetic Variations in HIV-1 Tat on LTR-Mediated Transcription via TAR RNA Interaction

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    Larance Ronsard

    2017-04-01

    Full Text Available HIV-1 evades host defense through mutations and recombination events, generating numerous variants in an infected patient. These variants with an undiminished virulence can multiply rapidly in order to progress to AIDS. One of the targets to intervene in HIV-1 replication is the trans-activator of transcription (Tat, a major regulatory protein that transactivates the long terminal repeat promoter through its interaction with trans-activation response (TAR RNA. In this study, HIV-1 infected patients (n = 120 from North India revealed Ser46Phe (20% and Ser61Arg (2% mutations in the Tat variants with a strong interaction toward TAR leading to enhanced transactivation activities. Molecular dynamics simulation data verified that the variants with this mutation had a higher binding affinity for TAR than both the wild-type Tat and other variants that lacked Ser46Phe and Ser61Arg. Other mutations in Tat conferred varying affinities for TAR interaction leading to differential transactivation abilities. This is the first report from North India with a clinical validation of CD4 counts to demonstrate the influence of Tat genetic variations affecting the stability of Tat and its interaction with TAR. This study highlights the co-evolution pattern of Tat and predominant nucleotides for Tat activity, facilitating the identification of genetic determinants for the attenuation of viral gene expression.

  10. HIV-1 Tat primes and activates microglial NLRP3 inflammasome-mediated neuroinflammation.

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    Chivero, Ernest T; Guo, Ming-Lei; Periyasamy, Palsamy; Liao, Ke; Callen, Shannon E; Buch, Shilpa

    2017-03-07

    Neuroinflammation associated with HIV-1 infection is a problem affecting ∼50% of HIV-infected individuals. NLRP3 inflammasome has been implicated in HIV-induced microglial activation, but the mechanism(s) remain unclear. Since HIV-Tat continues to be present despite antiretroviral therapy and activates NF-kB, we hypothesized that Tat could prime the NLRP3 inflammasome. We found a dose- and time-dependent induction of NLRP3 expression in microglia exposed to Tat compared with control. Tat exposure also time-dependently increased the mature caspase-1 and IL-1β levels and enhanced the IL-1β secretion. These in vitro findings were validated in archival brain tissues from SIV-infected and uninfected rhesus macaques. Further validation of NLRP3 priming in-vivo involved administration of LPS to HIV-1 transgenic (Tg) rats followed by assessment of IL-1β mRNA expression and inflammasome activation (ASC oligomers and mature IL-1β). Intriguingly, LPS potentiated upregulation of IL-1β mRNA and inflammasome activation in HIV-Tg rats compared with the wild type controls. Interestingly, we found an inverse relationship in the expression of NLRP3 and its negative regulator, miR-223, suggesting a miR-223-mediated mechanism for Tat-induced NLRP3 priming. Furthermore, blockade of NLRP3 resulted in decreased IL-1β secretion. Collectively, these findings suggest a novel role of Tat in priming and activating the NLRP3 inflammasome. Thus, NLRP3 can be envisioned as a therapeutic target for ameliorating Tat-mediated neuroinflammation.Significance StatementDespite successful suppression of viremia with increased longevity in the era of cART, chronic inflammation with underlying neurocognitive impairment continues to afflict almost 50% of infected individuals. Viral, bacterial and cellular products have all been implicated in promoting the chronic inflammation found in these individuals. Understanding the molecular mechanism(s) by which viral proteins such as HIV Tat can activate

  11. LRRK2 kinase inhibition prevents pathological microglial phagocytosis in response to HIV-1 Tat protein

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    Marker Daniel F

    2012-11-01

    Full Text Available Abstract Background Human Immunodeficiency Virus-1 (HIV-1 associated neurocognitive disorders (HANDs are accompanied by significant morbidity, which persists despite the use of combined antiretroviral therapy (cART. While activated microglia play a role in pathogenesis, changes in their immune effector functions, including phagocytosis and proinflammatory signaling pathways, are not well understood. We have identified leucine-rich repeat kinase 2 (LRRK2 as a novel regulator of microglial phagocytosis and activation in an in vitro model of HANDs, and hypothesize that LRRK2 kinase inhibition will attenuate microglial activation during HANDs. Methods We treated BV-2 immortalized mouse microglia cells with the HIV-1 trans activator of transcription (Tat protein in the absence or presence of LRRK2 kinase inhibitor (LRRK2i. We used Western blot, qRT-PCR, immunocytochemistry and latex bead engulfment assays to analyze LRRK2 protein levels, proinflammatory cytokine and phagocytosis receptor expression, LRRK2 cellular distribution and phagocytosis, respectively. Finally, we utilized ex vivo microfluidic chambers containing primary hippocampal neurons and BV-2 microglia cells to investigate microglial phagocytosis of neuronal axons. Results We found that Tat-treatment of BV-2 cells induced kinase activity associated phosphorylation of serine 935 on LRRK2 and caused the formation of cytoplasmic LRRK2 inclusions. LRRK2i decreased Tat-induced phosphorylation of serine 935 on LRRK2 and inhibited the formation of Tat-induced cytoplasmic LRRK2 inclusions. LRRK2i also decreased Tat-induced process extension in BV-2 cells. Furthermore, LRRK2i attenuated Tat-induced cytokine expression and latex bead engulfment. We examined relevant cellular targets in microfluidic chambers and found that Tat-treated BV-2 microglia cells cleared axonal arbor and engulfed neuronal elements, whereas saline treated controls did not. LRRK2i was found to protect axons in the presence

  12. Modulation of microtubule assembly by the HIV-1 Tat protein is strongly dependent on zinc binding to Tat

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    Muller Sylviane

    2008-07-01

    Full Text Available Abstract Background During HIV-1 infection, the Tat protein plays a key role by transactivating the transcription of the HIV-1 proviral DNA. In addition, Tat induces apoptosis of non-infected T lymphocytes, leading to a massive loss of immune competence. This apoptosis is notably mediated by the interaction of Tat with microtubules, which are dynamic components essential for cell structure and division. Tat binds two Zn2+ ions through its conserved cysteine-rich region in vitro, but the role of zinc in the structure and properties of Tat is still controversial. Results To investigate the role of zinc, we first characterized Tat apo- and holo-forms by fluorescence correlation spectroscopy and time-resolved fluorescence spectroscopy. Both of the Tat forms are monomeric and poorly folded but differ by local conformational changes in the vicinity of the cysteine-rich region. The interaction of the two Tat forms with tubulin dimers and microtubules was monitored by analytical ultracentrifugation, turbidity measurements and electron microscopy. At 20°C, both of the Tat forms bind tubulin dimers, but only the holo-Tat was found to form discrete complexes. At 37°C, both forms promoted the nucleation and increased the elongation rates of tubulin assembly. However, only the holo-Tat increased the amount of microtubules, decreased the tubulin critical concentration, and stabilized the microtubules. In contrast, apo-Tat induced a large amount of tubulin aggregates. Conclusion Our data suggest that holo-Tat corresponds to the active form, responsible for the Tat-mediated apoptosis.

  13. HIV-1 Tat RNA silencing suppressor activity is conserved across kingdoms and counteracts translational repression of HIV-1.

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    Qian, Shuiming; Zhong, Xuehua; Yu, Lianbo; Ding, Biao; de Haan, Peter; Boris-Lawrie, Kathleen

    2009-01-13

    The RNA silencing pathway is an intracellular innate response to virus infections and retro-transposons. Many plant viruses counter this host restriction by RNA silencing suppressor (RSS) activity of a double-stranded RNA-binding protein, e.g., tomato bushy stunt virus P19. Here, we demonstrate P19 and HIV-1 Tat function across the plant and animal kingdoms and suppress a common step in RNA silencing that is downstream of small RNA maturation. Our experiments reveal that RNA silencing in HIV-1 infected human cells severely attenuates the translational output of the unspliced HIV-1 gag mRNA, and possibly all HIV-1 transcripts. The attenuation in gag mRNA translation is exacerbated by K51A substitution in the Tat double-stranded RNA-binding domain. Tat, plant virus RSS, or Dicer downregulation rescues robust gag translation and bolsters HIV-1 virion production. The reversal of HIV-1 translation repression by plant RSS supports the recent finding in Arabidopsis that plant miRNAs operate by translational inhibition. Our results identify common features between RNA silencing suppression of plant and animal viruses. We suggest that RNA silencing-mediated translation repression plays a strategic role in determining the viral set-point in a newly HIV-1-infected patient.

  14. Effect of HIV-1 Tat on Secretion of TNF-α and IL-1β by U87 Cells in AIDS Patients with or without AIDS Dementia Complex

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    ZHAO Li; PUShuangShuang; GAO WenHua; CHIYuanYuan; WENHong Ling; WANG Zhi Yu; SONGYanYan; YU Xue Jie

    2014-01-01

    ObjectiveToexplore the role of HIV-1 tat gene variations in AIDSdementia complex(ADC) pathogenesis. MethodsHIV-1tat genes derived from peripheral spleen and central basal ganglia of anAIDSpatient with ADC and anAIDSpatientwithoutADC were cloned for sequence analysis. HIV-1 tat genesequence alignmentwasperformed by using CLUSTAL W andthephylogentic analysiswas conductedbyusing Neighbor-joining with MEGA4 software.All tat genes wereused to construct recombinant retroviral expressing vector MSCV-IRES-GFP/tat. The MSCV-IRES-GFP/tat was cotransfected into 293T cells with pCMV-VSV-G and pUMVC vectorsto assemble the recombinant retrovirus. After infection of gliomas U87 cells with equal amount of the recombinant retrovirus, TNF-α, and IL-1β concentrations inthe supernatant of U87 cells were determined with ELISA. ResultsHIV-1tat genes derived from peripheral spleen and central basal ganglia ofthe AIDS patient with ADC andtheother onewithoutADCexhibited genetic variations.Tat variations and amino acid mutation sites existed mainly at Tat protein core functional area (38-47aa). All Tat proteinscould induce U87 cells to produce TNF-α and IL-1β, but thelevel of IL-1β production was different among Tatproteins derived fromtheADC patient’s spleen, basal ganglia, andthenon-ADC patient’s spleen.The level ofTat proteinsderived fromtheADC patient’s spleen,basal ganglia, andthenon-ADC patient’sspleen were obviously higher thanthat fromthe non-ADC patient’s basal ganglia. ConclusionTat protein core functional area (38-47aa) mayserve as the key area of enhancing the secretion of IL-1β.This may be related with the neurotoxicity of HIV-1 Tat. ObjectiveToexplore the role of HIV-1 tat gene variations in AIDSdementia complex(ADC) pathogenesis. MethodsHIV-1tat genes derived from peripheral spleen and central basal ganglia of anAIDSpatient with ADC and anAIDSpatientwithoutADC were cloned for sequence analysis. HIV-1 tat genesequence alignmentwasperformed by using CLUSTAL W

  15. Detection of human immunodeficiency virus type 1 (HIV-1) Tat protein by aptamer-based biosensors

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    Hashim, Uda; Fatin, M. F.; Ruslinda, A. R.; Gopinath, Subash C. B.; Uda, M. N. A.

    2017-03-01

    A study was conducted to detect the human immunodeficiency virus (HIV-1) Tat protein using interdigitated electrodes. The measurements and images of the IDEs' finger gaps and the images of chitosan-carbon nanotubes deposited on top of the interdigitated electrodes were taken using the Scanning Electron Microscope. The detection of HIV-1 Tat protein was done using split aptamers and aptamer tail. Biosensors were chosen as diagnostic equipment due to their rapid diagnostic capabilities.

  16. HIV-1 Tat and Viral Latency: What We Can Learn from Naturally Occurring Sequence Variations

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    Kamori, Doreen; Ueno, Takamasa

    2017-01-01

    Despite the effective use of antiretroviral therapy, the remainder of a latently HIV-1-infected reservoir mainly in the resting memory CD4+ T lymphocyte subset has provided a great setback toward viral eradication. While host transcriptional silencing machinery is thought to play a dominant role in HIV-1 latency, HIV-1 protein such as Tat, may affect both the establishment and the reversal of latency. Indeed, mutational studies have demonstrated that insufficient Tat transactivation activity can result in impaired transcription of viral genes and the establishment of latency in cell culture experiments. Because Tat protein is one of highly variable proteins within HIV-1 proteome, it is conceivable that naturally occurring Tat mutations may differentially modulate Tat functions, thereby influencing the establishment and/or the reversal of viral latency in vivo. In this mini review, we summarize the recent findings of Tat naturally occurring polymorphisms associating with host immune responses and we highlight the implication of Tat sequence variations in relation to HIV latency.

  17. HIV-1 Tat C-mediated regulation of tumor necrosis factor receptor-associated factor-3 by microRNA 32 in human microglia

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    Mishra Ritu

    2012-06-01

    Full Text Available Abstract Background HIV-1 Tat protein is known to be associated with neuroinflammation, a condition that develops in almost half of patients infected with HIV-1. HIV-1 Tat can alter glial neuroprotective functions, leading to neurotoxicity within the CNS. HIV-1 Tat is known to be secreted from productively infected cells and can affect neighboring uninfected cells by modulating cellular gene expression in a bystander fashion. Methods We were interested to study whether exogenous exposure to HIV-1 Tat-C protein perturbs the microRNA (miRNA expression profile of human microglial cells, leading to altered protein expression. We used protein expression and purification, miRNA overexpression, miRNA knockdown, transfection, site-directed mutagenesis, real-time PCR, luciferase assay and western blotting techniques to perform our study. Results HIV-1 Tat-C treatment of human microglial cells resulted in a dose-dependent increase in miR-32 expression. We found that tumor necrosis factor-receptor–associated factor 3 TRAF3 is a direct target for miR-32, and overexpression of miR-32 in CHME3 cells decreased TRAF3 both at the mRNA and the protein level. Recovery of TRAF3 protein expression after transfection of anti-miR-32 and the results of the luciferase reporter assay provided direct evidence of TRAF3 regulation by miR-32. We found that the regulation of interferon regulatory factor 3 (IRF3 and IRF7 is controlled by cellular levels of TRAF3 protein in microglial cells, as after overexpression of miR-32 and application of anti-miR-32, expression levels of IRF3 and IRF7 were inversely regulated by expression levels of TRAF3. Thus, our results suggest a novel miRNA mediated mechanism for regulation of TRAF3 in human microglial cells exposed to HIV-1 Tat C protein. These results may help to elucidate the detrimental neuroinflammatory consequences of HIV-1 Tat C protein in bystander fashion. Conclusion HIV-1 Tat protein can modulate TRAF3 expression through

  18. Interaction between Tat and Drugs of Abuse during HIV-1 Infection and Central Nervous System Disease

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    Monique E Maubert

    2016-01-01

    Full Text Available In many individuals, drug abuse is intimately linked with HIV-1 infection. In addition to being associated with one-third of all HIV-1 infections in the United States, drug abuse also plays a role in disease progression and severity in HIV-1-infected patients, including adverse effects on the central nervous system (CNS. Specific systems within the brain are known to be damaged in HIV-1-infected individuals and this damage is similar to that observed in drug abuse. Even in the era of anti-retroviral therapy (ART, CNS pathogenesis occurs with HIV-1 infection, with a broad range of cognitive impairment observed, collectively referred to as HIV-1-associated neurocognitive disorders (HAND. A number of HIV-1 proteins (Tat, gp120, Nef, Vpr have been implicated in the etiology of pathogenesis and disease as a result of the biologic activity of the extracellular form of each of the proteins in a number of tissues, including the CNS, even in ART-suppressed patients. In this review, we have made Tat the center of attention for a number of reasons. First, it has been shown to be synthesized and secreted by HIV-1-infected cells in the CNS, despite the most effective suppression therapies available to date. Second, Tat has been shown to alter the functions of several host factors, disrupting the molecular and biochemical balance of numerous pathways contributing to cellular toxicity, dysfunction, and death. In addition, the advantages and disadvantages of ART suppression with regard to controlling the genesis and progression of neurocognitive impairment are currently under debate in the field and are yet to be fully determined. In this review, we discuss the individual and concerted contributions of HIV-1 Tat, drug abuse, and ART with respect to damage in the CNS, and how these factors contribute to the development of HAND in HIV-1-infected patients.

  19. Homonuclear 1H NMR and circular dichroism study of the HIV-1 Tat Eli variant

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    Watkins, Jennifer D; Campbell, Grant R; Halimi, Hubert; Loret, Erwann P

    2008-01-01

    Background The HIV-1 Tat protein is a promising target to develop AIDS therapies, particularly vaccines, due to its extracellular role that protects HIV-1-infected cells from the immune system. Tat exists in two different lengths, 86 or 87 residues and 99 or 101 residues, with the long form being predominant in clinical isolates. We report here a structural study of the 99 residue Tat Eli variant using 2D liquid-state NMR, molecular modeling and circular dichroism. Results Tat Eli was obtained from solid-phase peptide synthesis and the purified protein was proven biologically active in a trans-activation assay. Circular dichroism spectra at different temperatures up to 70°C showed that Tat Eli is not a random coil at 20°C. Homonuclear 1H NMR spectra allowed us to identify 1639 NMR distance constraints out of which 264 were interresidual. Molecular modeling satisfying at least 1474 NMR constraints revealed the same folding for different model structures. The Tat Eli model has a core region composed of a part of the N-terminus including the highly conserved Trp 11. The extra residues in the Tat Eli C-terminus protrude from a groove between the basic region and the cysteine-rich region and are well exposed to the solvent. Conclusion We show that active Tat variants share a similar folding pattern whatever their size, but mutations induce local structural changes. PMID:18808674

  20. Molecular mechanism: the human dopamine transporter histidine 547 regulates basal and HIV-1 Tat protein-inhibited dopamine transport.

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    Quizon, Pamela M; Sun, Wei-Lun; Yuan, Yaxia; Midde, Narasimha M; Zhan, Chang-Guo; Zhu, Jun

    2016-12-14

    Abnormal dopaminergic transmission has been implicated as a risk determinant of HIV-1-associated neurocognitive disorders. HIV-1 Tat protein increases synaptic dopamine (DA) levels by directly inhibiting DA transporter (DAT) activity, ultimately leading to dopaminergic neuron damage. Through integrated computational modeling prediction and experimental validation, we identified that histidine547 on human DAT (hDAT) is critical for regulation of basal DA uptake and Tat-induced inhibition of DA transport. Compared to wild type hDAT (WT hDAT), mutation of histidine547 (H547A) displayed a 196% increase in DA uptake. Other substitutions of histidine547 showed that DA uptake was not altered in H547R but decreased by 99% in H547P and 60% in H547D, respectively. These mutants did not alter DAT surface expression or surface DAT binding sites. H547 mutants attenuated Tat-induced inhibition of DA transport observed in WT hDAT. H547A displays a differential sensitivity to PMA- or BIM-induced activation or inhibition of DAT function relative to WT hDAT, indicating a change in basal PKC activity in H547A. These findings demonstrate that histidine547 on hDAT plays a crucial role in stabilizing basal DA transport and Tat-DAT interaction. This study provides mechanistic insights into identifying targets on DAT for Tat binding and improving DAT-mediated dysfunction of DA transmission.

  1. The histone chaperone protein Nucleosome Assembly Protein-1 (hNAP-1 binds HIV-1 Tat and promotes viral transcription

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    Marcello Alessandro

    2008-01-01

    Full Text Available Abstract Background Despite the large amount of data available on the molecular mechanisms that regulate HIV-1 transcription, crucial information is still lacking about the interplay between chromatin conformation and the events that regulate initiation and elongation of viral transcription. During transcriptional activation, histone acetyltransferases and ATP-dependent chromatin remodeling complexes cooperate with histone chaperones in altering chromatin structure. In particular, human Nucleosome Assembly Protein-1 (hNAP-1 is known to act as a histone chaperone that shuttles histones H2A/H2B into the nucleus, assembles nucleosomes and promotes chromatin fluidity, thereby affecting transcription of several cellular genes. Results Using a proteomic screening, we identified hNAP-1 as a novel cellular protein interacting with HIV-1 Tat. We observed that Tat specifically binds hNAP1, but not other members of the same family of factors. Binding between the two proteins required the integrity of the basic domain of Tat and of two separable domains of hNAP-1 (aa 162–290 and 290–391. Overexpression of hNAP-1 significantly enhanced Tat-mediated activation of the LTR. Conversely, silencing of the protein decreased viral promoter activity. To explore the effects of hNAP-1 on viral infection, a reporter HIV-1 virus was used to infect cells in which hNAP-1 had been either overexpressed or knocked-down. Consistent with the gene expression results, these two treatments were found to increase and inhibit viral infection, respectively. Finally, we also observed that the overexpression of p300, a known co-activator of both Tat and hNAP-1, enhanced hNAP-1-mediated transcriptional activation as well as its interaction with Tat. Conclusion Our study reveals that HIV-1 Tat binds the histone chaperone hNAP-1 both in vitro and in vivo and shows that this interaction participates in the regulation of Tat-mediated activation of viral gene expression.

  2. Direct effects of HIV-1 Tat on excitability and survival of primary dorsal root ganglion neurons: possible contribution to HIV-1-associated pain.

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    Xianxun Chi

    Full Text Available The vast majority of people living with human immunodeficiency virus type 1 (HIV-1 have pain syndrome, which has a significant impact on their quality of life. The underlying causes of HIV-1-associated pain are not likely attributable to direct viral infection of the nervous system due to the lack of evidence of neuronal infection by HIV-1. However, HIV-1 proteins are possibly involved as they have been implicated in neuronal damage and death. The current study assesses the direct effects of HIV-1 Tat, one of potent neurotoxic viral proteins released from HIV-1-infected cells, on the excitability and survival of rat primary dorsal root ganglion (DRG neurons. We demonstrated that HIV-1 Tat triggered rapid and sustained enhancement of the excitability of small-diameter rat primary DRG neurons, which was accompanied by marked reductions in the rheobase and resting membrane potential (RMP, and an increase in the resistance at threshold (R(Th. Such Tat-induced DRG hyperexcitability may be a consequence of the inhibition of cyclin-dependent kinase 5 (Cdk5 activity. Tat rapidly inhibited Cdk5 kinase activity and mRNA production, and roscovitine, a well-known Cdk5 inhibitor, induced a very similar pattern of DRG hyperexcitability. Indeed, pre-application of Tat prevented roscovitine from having additional effects on the RMP and action potentials (APs of DRGs. However, Tat-mediated actions on the rheobase and R(Th were accelerated by roscovitine. These results suggest that Tat-mediated changes in DRG excitability are partly facilitated by Cdk5 inhibition. In addition, Cdk5 is most abundant in DRG neurons and participates in the regulation of pain signaling. We also demonstrated that HIV-1 Tat markedly induced apoptosis of primary DRG neurons after exposure for longer than 48 h. Together, this work indicates that HIV-1 proteins are capable of producing pain signaling through direct actions on excitability and survival of sensory neurons.

  3. BSA conjugates bearing multiple copies of the basic domain of HIV-1 Tat: Prototype for the development of multitarget inhibitors of extracellular Tat.

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    Bugatti, Antonella; Chiodelli, Paola; Rosenbluh, Joseph; Loyter, Abraham; Rusnati, Marco

    2010-07-01

    The transactivating factor (Tat) of HIV-1 is involved in AIDS progression and associated pathologies. Tat possesses a basic amino acid sequence implicated in heparan sulfate proteoglycan (HSPG)-mediated internalization, nuclear localization and transactivation by Tat and in the interaction of Tat with integrins and with the vascular endothelial growth factor receptor 2 (KDR) (kinase insert domain receptor). A BSA conjugate bearing an average of four copies of a peptide representing the basic domain/nuclear localization signal of Tat (BSA-Tat-NLS) inhibits transactivation by Tat exogenously added to cells but not by Tat endogenously produced after cell transfection with a tat cDNA, indicating that BSA-Tat-NLS does not interfere with Tat at an intracellular level. Surface plasmon resonance (SPR) experiments revealed that BSA-Tat-NLS binds to the HSPG analogue heparin. Accordingly, BSA-Tat-NLS binds to HSPGs of HL3T1 cell surface and inhibits HSPG-dependent Tat internalization. BSA-Tat-NLS retains its inhibitory potential when pre-incubated with HL3T1 cells before Tat administration, possibly by masking cell-surface HSPGs thus preventing Tat binding and internalization. SPR experiments revealed that BSA-Tat-NLS binds also to integrin alpha(v)beta(3) and KDR. Accordingly, it inhibits pro-angiogenic endothelial cell adhesion to Tat and motogenesis. In conclusion, BSA-Tat-NLS binds/masks three different cell-surface receptors of Tat inhibiting different biological activities. These data point to BSA-Tat-NLS as a prototype for the development of Tat-antagonists endowed with a multitargeted mechanism of action.

  4. Cannabinoids Occlude the HIV-1 Tat-Induced Decrease in GABAergic Neurotransmission in Prefrontal Cortex Slices.

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    Xu, Changqing; Hermes, Douglas J; Mackie, Ken; Lichtman, Aron H; Ignatowska-Jankowska, Bogna M; Fitting, Sylvia

    2016-06-01

    In the era of combined antiretroviral therapy (cART), human immunodeficiency virus type 1 (HIV-1) is now considered a chronic disease that specifically targets the brain and causes HIV-1-associated neurocognitive disorders (HAND). Endocannabinoids exhibit neuroprotective and anti-inflammatory properties in several central nervous system (CNS) disease models, but their effects in HAND are poorly understood. To address this issue, whole-cell recordings were performed on young (14-24 day old) C57BL/6J mice. We investigated the actions of the synthetic cannabinoid WIN55,212-2 (1 μM) and the endocannabinoid N-arachidonoyl ethanolamine (anandamide; AEA, 1 μM) in the presence of HIV-1 Tat on GABAergic neurotransmission in mouse prefrontal cortex (PFC) slices. We found a Tat concentration-dependent (5-50 nM) decrease in the frequency and amplitude of miniature inhibitory postsynaptic currents (mIPSCs). The cannabinoid 1 receptor (CB1R) antagonist rimonabant (1 μM) and zero extracellular calcium prevented the significant Tat-induced decrease in mIPSCs. Further, bath-applied WIN55,212-2 or AEA by itself, significantly decreased the frequency, but not amplitude of mIPSCs and/or spontaneous IPSCs (sIPSCs), and occluded a further downregulation of IPSCs by Tat. Pretreatment with rimonabant but not the CB2R antagonist AM630 (1 μM) prevented the WIN55,212-2- and AEA-induced decrease in IPSCs frequency without any further Tat effect. Results indicated a Tat-induced decrease in GABAergic neurotransmission, which was occluded by cannabinoids via a CB1R-related mechanism. Understanding the relationship between Tat toxicity and endocannabinoid signaling has the potential to identify novel therapeutic interventions to benefit individuals suffering from HAND and other cognitive impairments.

  5. The HIV-1 transactivator factor (Tat induces enterocyte apoptosis through a redox-mediated mechanism.

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    Vittoria Buccigrossi

    Full Text Available The intestinal mucosa is an important target of human immunodeficiency virus (HIV infection. HIV virus induces CD4+ T cell loss and epithelial damage which results in increased intestinal permeability. The mechanisms involved in nutrient malabsorption and alterations of intestinal mucosal architecture are unknown. We previously demonstrated that HIV-1 transactivator factor (Tat induces an enterotoxic effect on intestinal epithelial cells that could be responsible for HIV-associated diarrhea. Since oxidative stress is implicated in the pathogenesis and morbidity of HIV infection, we evaluated whether Tat induces apoptosis of human enterocytes through oxidative stress, and whether the antioxidant N-acetylcysteine (NAC could prevent it. Caco-2 and HT29 cells or human intestinal mucosa specimens were exposed to Tat alone or combined with NAC. In an in-vitro cell model, Tat increased the generation of reactive oxygen species and decreased antioxidant defenses as judged by a reduction in catalase activity and a reduced (GSH/oxidized (GSSG glutathione ratio. Tat also induced cytochrome c release from mitochondria to cytosol, and caspase-3 activation. Rectal dialysis samples from HIV-infected patients were positive for the oxidative stress marker 8-hydroxy-2'-deoxyguanosine. GSH/GSSG imbalance and apoptosis occurred in jejunal specimens from HIV-positive patients at baseline and from HIV-negative specimens exposed to Tat. Experiments with neutralizing anti-Tat antibodies showed that these effects were direct and specific. Pre-treatment with NAC prevented Tat-induced apoptosis and restored the glutathione balance in both the in-vitro and the ex-vivo model. These findings indicate that oxidative stress is one of the mechanism involved in HIV-intestinal disease.

  6. Direct interaction of the human I-mfa domain-containing protein, HIC, with HIV-1 Tat results in cytoplasmic sequestration and control of Tat activity.

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    Gautier, Virginie W; Sheehy, Noreen; Duffy, Margaret; Hashimoto, Kenichi; Hall, William W

    2005-11-08

    The primary function of the HIV-1 regulatory protein Tat, activation of transcription from the viral LTR, is highly regulated by complex interactions between Tat and a number of host cell proteins. Tat nuclear import, a process mediated by importin beta, is a prerequisite for its activity. Here, we report and characterize the interaction of the human inhibitor of MyoD family domain-containing protein (I-mfa), HIC, with Tat at a biochemical and a functional level. This interaction was shown to occur in vivo and in vitro and to involve the nuclear localization signal and the transactivation responsive element-binding domains of Tat and the I-mfa domain of HIC. Coexpression of HIC and Tat resulted in the down-regulation of transactivation of the HIV-1 LTR, and colocalization studies revealed the cytoplasmic sequestration of Tat by HIC. Functionally this sequestration appears to be the underlying mechanism of LTR transcriptional repression by HIC and represents a unique mechanism for the control of Tat activity and regulation of HIV-1 replication.

  7. Design and SAR of new substituted purines bearing aryl groups at N9 position as HIV-1 Tat-TAR interaction inhibitors.

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    Pang, Ruifang; Zhang, Chunlei; Yuan, Dekai; Yang, Ming

    2008-09-01

    Twenty-four purine derivatives bearing aryl groups at N9 position were designed and synthesized as HIV-1 Tat-TAR interaction inhibitors. All the compounds showed high antiviral activities in inhibiting the formation of SIV-induced syncytium in CEM174 cells. Ten of them with low cytotoxicities were evaluated by Tat dependent HIV-1 LTR-driven CAT gene expression colorimetric enzyme assay in human 293T cells at a concentration of 30 microM, indicating effective inhibitory activities of blocking the Tat-TAR interaction. The aryl groups at N9 position affected the binding affinities between compounds and TAR RNA, showing some specificities of aryl groups to TAR RNA.

  8. Dynamic Post-Transcriptional Regulation of HIV-1 Gene Expression

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    Kula, Anna; Marcello, Alessandro

    2012-01-01

    Gene expression of the human immunodeficiency virus type 1 (HIV-1) is a highly regulated process. Basal transcription of the integrated provirus generates early transcripts that encode for the viral products Tat and Rev. Tat promotes the elongation of RNA polymerase while Rev mediates the nuclear export of viral RNAs that contain the Rev-responsive RNA element (RRE). These RNAs are exported from the nucleus to allow expression of Gag-Pol and Env proteins and for the production of full-length genomic RNAs. A balance exists between completely processed mRNAs and RRE-containing RNAs. Rev functions as an adaptor that recruits cellular factors to re-direct singly spliced and unspliced viral RNAs to nuclear export. The aim of this review is to address the dynamic regulation of this post-transcriptional pathway in light of recent findings that implicate several novel cellular cofactors of Rev function. PMID:24832221

  9. Dynamic Post-Transcriptional Regulation of HIV-1 Gene Expression

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    Alessandro Marcello

    2012-07-01

    Full Text Available Gene expression of the human immunodeficiency virus type 1 (HIV-1 is a highly regulated process. Basal transcription of the integrated provirus generates early transcripts that encode for the viral products Tat and Rev. Tat promotes the elongation of RNA polymerase while Rev mediates the nuclear export of viral RNAs that contain the Rev-responsive RNA element (RRE. These RNAs are exported from the nucleus to allow expression of Gag-Pol and Env proteins and for the production of full-length genomic RNAs. A balance exists between completely processed mRNAs and RRE-containing RNAs. Rev functions as an adaptor that recruits cellular factors to re-direct singly spliced and unspliced viral RNAs to nuclear export. The aim of this review is to address the dynamic regulation of this post-transcriptional pathway in light of recent findings that implicate several novel cellular cofactors of Rev function.

  10. CTL Responses to Regulatory Proteins Tat and Rev in HIV-1 B'/C Virus-Infected Individuals

    Institute of Scientific and Technical Information of China (English)

    MING-MING JIA; KUN-XUE HONG; JIAN-PING CHEN; HONG-WEI LIU; SHA LIU; XIAO-QING ZHANG; HONG-JING ZHAO; YI-MING SHAO

    2008-01-01

    To characterize HIV-1 specific CTL responses to regulatory proteins Tat and Rev in HIV-B'/C vires-infected ART-naive individuals. Methods HIV-1-specific CTL responses were analyzed by IFN-γ ELISPOT assay using overlapping peptides spanning the consensus sequences of HIV-1 clade C Tat and Rev proteins. Statistical analysis and graphical presentation were performed using SIGMAPLOT 10.0 and SIGMASTAT 3.5. For samples with a positive response, the magnitude of CTL responses was compared between HIV-1 C proteins by Wilcoxon rank sum test, and the significance threshold was P<0.05. Results Tat and Rev were frequently recognized, with 23% and 52% of the tested individuals having detectable responses to these proteins, respectively. Several immunodominant regions were detected in Rev. No significant correlation was observed between the magnitude and breadth of CTL responses to regulatory proteins and the control of virus replication in this study. Conclusion Tat and Rev can serve as targets for HIV-1-specific CTL, and several immunodominant regions are detectable in Rev. Further characterization of epitopes and their role in virus control may shed light on pathogenesis of HIV-1 natural infection and also be useful for the design and testing of candidate vaccines.

  11. Endocannabinoids affect innate immunity of Muller glia during HIV-1 Tat cytotoxicity.

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    Krishnan, Gopinath; Chatterjee, Nivedita

    2014-03-01

    In the retina, increased inflammatory response can cause visual impairment during HIV infection in spite of successful anti-retroviral therapy (HAART). The HIV-1 Tat protein is implicated in neurodegeneration by eliciting a cytokine response in cells of the CNS, including glia. The current study investigated whether innate immune response in human retinal Muller glia could be immune-modulated to combat inflammation. Endocannabinoids, N-arachidonoylethanolamide and 2-arachidonoylglycerol are used to alleviate Tat-induced cytotoxicity and rescue retinal cells. The neuroprotective mechanism involved suppression in production of pro-inflammatory and increase of anti-inflammatory cytokines, mainly through the MAPK pathway. The MAPK regulation was primarily by MKP-1. Both endocannabinoids regulated cytokine production by affecting at the transcriptional level the NF-κB complex, including IRAK1BP1 and TAB2. Stability of cytokine mRNA is likely to have been influenced through tristetraprolin. These findings have direct relevance in conditions like immune-recovery uveitis where anti-retroviral therapy has helped immune reconstitution. In such conditions drugs to combat overwhelming inflammatory response would need to supplement HAART. Endocannabinoids and their agonists may be thought of as neurotherapeutic during certain conditions of HIV-1 induced inflammation.

  12. Molecular and Genetic Characterization of HIV-1 Tat Exon-1 Gene from Cameroon Shows Conserved Tat HLA-Binding Epitopes: Functional Implications

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    Teto, Georges; Fonsah, Julius Y.; Tagny, Claude T.; Mbanya, Dora; Nchindap, Emilienne; Kenmogne, Leopoldine; Fokam, Joseph; Njamnshi, Dora M.; Kouanfack, Charles; Njamnshi, Alfred K.; Kanmogne, Georgette D.

    2016-01-01

    HIV-1 Tat plays a critical role in viral transactivation. Subtype-B Tat has potential use as a therapeutic vaccine. However, viral genetic diversity and population genetics would significantly impact the efficacy of such a vaccine. Over 70% of the 37-million HIV-infected individuals are in sub-Saharan Africa (SSA) and harbor non-subtype-B HIV-1. Using specimens from 100 HIV-infected Cameroonians, we analyzed the sequences of HIV-1 Tat exon-1, its functional domains, post-translational modifications (PTMs), and human leukocyte antigens (HLA)-binding epitopes. Molecular phylogeny revealed a high genetic diversity with nine subtypes, CRF22_01A1/CRF01_AE, and negative selection in all subtypes. Amino acid mutations in Tat functional domains included N24K (44%), N29K (58%), and N40K (30%) in CRF02_AG, and N24K in all G subtypes. Motifs and phosphorylation analyses showed conserved amidation, N-myristoylation, casein kinase-2 (CK2), serine and threonine phosphorylation sites. Analysis of HLA allelic frequencies showed that epitopes for HLAs A*0205, B*5301, Cw*0401, Cw*0602, and Cw*0702 were conserved in 58%–100% of samples, with B*5301 epitopes having binding affinity scores > 100 in all subtypes. This is the first report of N-myristoylation, amidation, and CK2 sites in Tat; these PTMs and mutations could affect Tat function. HLA epitopes identified could be useful for designing Tat-based vaccines for highly diverse HIV-1 populations, as in SSA. PMID:27438849

  13. Depicting Binding-Mediated Translocation of HIV-1 Tat Peptides in Living Cells with Nanoscale Pens of Tat-Conjugated Quantum Dots

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    Lin, Chien Y.; Huang, Jung Y.; Lo, Leu-Wei

    2017-01-01

    Cell-penetrating peptides (CPPs) can translocate across cell membranes, and thus have great potential for the cellular delivery of macromolecular cargoes. However, the mechanism of this cellular uptake process is not yet fully understood. In this study, a time-lapse single-particle light-sheet microscopy technique was implemented to obtain a parallel visualization of the translocating process of individual human immunodeficiency virus 1 (HIV-1) transactivator of transcription (Tat) peptide conjugated quantum dots (TatP-QDs) in complex cellular terrains. Here, TatP-QDs served as nanoscale dynamic pens, which depict remarkable trajectory aggregates of TatP-QDs on the cell surface. Spectral-embedding analysis of the trajectory aggregates revealed a manifold formed by isotropic diffusion and a fraction of directed movement, possibly caused by interaction between the Tat peptides and heparan sulfate groups on the plasma membrane. Further analysis indicated that the membrane deformation induced by Tat-peptide attachment increased with the disruption of the actin framework in cytochalasin D (cyto D)-treated cells, yielding higher interactions on the TatP-QDs. In native cells, the Tat peptides can remodel the actin framework to reduce their interaction with the local membrane environment. Characteristic hot spots for interaction were detected on the membrane, suggesting that a funnel passage may have formed for the Tat-coated particles. This finding offers valuable insight into the cellular delivery of nanoscale cargo, suggesting an avenue for direct therapeutic delivery. PMID:28208588

  14. HIV-1 Tat activates indoleamine 2,3 dioxygenase in murine organotypic hippocampal slice cultures in a p38 mitogen-activated protein kinase-dependent manner

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    Kelley Keith W

    2011-08-01

    Full Text Available Abstract Background We have established that activation of the tryptophan degrading enzyme indoleamine 2,3 dioxygenase (IDO mediates the switch from cytokine-induced sickness behavior to depressive-like behavior. Because human immunodeficiency virus type 1 (HIV-1 Tat protein causes depressive-like behavior in mice, we investigated its ability to activate IDO in organotypic hippocampal slice cultures (OHSCs derived from neonatal C57BL/6 mice. Methods Depressive-like behavior in C57BL/6J mice was assessed by the forced swim test. Expression of cytokines and IDO mRNA in OHSCs was measured by real-time RT-PCR and cytokine protein was measured by enzyme-linked immunosorbent assays (ELISAs. p38 MAPK phosphorylation was analyzed by western blot. Results Intracerebroventricular (i.c.v. administration of Tat (40 ng induced depressive-like behavior in the absence of sickness. Addition of Tat (40 ng/slice to the medium of OHSCs induced IDO steady-state mRNA that peaked at 6 h. This effect was potentiated by pretreatment with IFNγ. Tat also induced the synthesis and release of TNFα and IL-6 protein in the supernatant of the slices and increased expression of the inducible isoform of nitric oxide synthase (iNOS and the serotonin transporter (SERT. Tat had no effect on endogenous synthesis of IFNγ. To explore the mechanisms of Tat-induced IDO expression, slices were pretreated with the p38 mitogen-activated protein kinase (MAPK inhibitor SB 202190 for 30 min before Tat treatment. SB 202190 significantly decreased IDO expression induced by Tat, and this effect was accompanied by a reduction of Tat-induced expression of TNFα, IL-6, iNOS and SERT. Conclusion These data establish that Tat induces IDO expression via an IFNγ-independent mechanism that depends upon activation of p38 MAPK. Targeting IDO itself or the p38 MAPK signaling pathway could provide a novel therapy for comorbid depressive disorders in HIV-1-infected patients.

  15. A Novel HIV-1 Therapeutic Target:Tat Transactivator protein%一个新的HIV-1治疗靶--Tat转录激活蛋白

    Institute of Scientific and Technical Information of China (English)

    梁伟; 王亚芹; DAVALIAN DARIUSH

    2004-01-01

    Tat is a HIV-1 transaction transcriptional activator protein and plays a pivotal role in viral replication and in several AIDS-associated pathologies. Its biological properties and functions make it as a good candidate for the development of an anti-AIDS vaccine and/or drug. Strategies designing vaccines and drugs for anti-AIDS include vaccines derived from Tat, extracellular Tat-binding antagonists, inhibitors of Tat-activated intracellular second messengers, anti-Tat antisense,anti-TAR antisense, decoy and antagonists, anti-Tat intracellular intrabody, inhibitors of intracellular Tat cofactors and so on. An effective anti-AIDS therapy will require a multi-targeted approach in which classic antiviral drugs and protease inhibitors are combined with novel extracellular and intracellular Tat antagonists. This approach could prevent the development of drug-resistant HIV strains and decrease the dosage and related toxicity of each single drug and lead to a cure for AIDS-associated pathologies.%Tat是HIV-1病毒进行转录和复制的一个十分重要的蛋白质,同时,Tat也与HIV-1感染引起的严重病理学程度密切相关.Tat的生物学性质和功能决定了其是一个理想的开发抗AIDS疫苗和药物的靶蛋白.基于Tat自身及其作用的TARRNA,可以设计Tat疫苗、细胞外结合Tat的拮抗剂、抗Tat的反义核酸、抗TAR的反义核酸、抗Tat的细胞内抗体和细胞内Tat协同因子的抑制剂等.传统的抗病毒药物及蛋白酶抑制剂与新的细胞内和细胞外Tat拮抗剂联合使用,多靶点地抑制HIV-1的复制将是一个有效的抗AIDS的治疗方案.这一治疗方案能够防止HIV病毒耐药株的产生,减少单一作用靶点药物的用药剂量和降低相应的毒性,最终治愈AIDS相关的病理学变化.

  16. On the role of the second coding exon of the HIV-1 Tat protein in virus replication and MHC class I downregulation.

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    Verhoef, K; Bauer, M; Meyerhans, A; Berkhout, B

    1998-11-20

    Tat is an essential protein of human immunodeficiency virus type 1 (HIV-1) and activates transcription from the viral long terminal repeat (LTR) promoter. The tat gene is composed of two coding exons of which the first, corresponding to the N-terminal 72 amino acid residues, has been reported to be sufficient for its transcription function. We introduced a stop codon at the end of the first Tat-coding exon in an expression vector that produces a truncated 71-amino acid Tat protein. This Q72stop mutant displays reduced transcriptional activity of approximately 54% in transient LTR-CAT transfection assays. To test the contribution of the second Tat-coding exon to virus replication, the Q72stop mutation was also introduced in the infectious pLAI molecular clone. The effect on virus replication was analyzed in primary cells and in a transformed T cell line. The fitness of the mutant virus was calculated to be approximately 75% compared with the wild-type control. Thus, a small contribution of the C-terminal Tat domain to viral fitness was measured. It has been proposed that the second Tat-coding exon is involved in transcriptional downregulation of the MHC class I gene of the infected host cell. Cell surface expression of the MHC protein was analyzed in T cells infected with the wild-type LAI virus and the replication-competent Q72stop mutant. MHC expression was transiently reduced on infection with either virus, indicating that the second Tat-coding exon is not involved in this downregulation.

  17. HIV-1 Tat activates neuronal ryanodine receptors with rapid induction of the unfolded protein response and mitochondrial hyperpolarization.

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    John P Norman

    Full Text Available Neurologic disease caused by human immunodeficiency virus type 1 (HIV-1 is ultimately refractory to highly active antiretroviral therapy (HAART because of failure of complete virus eradication in the central nervous system (CNS, and disruption of normal neural signaling events by virally induced chronic neuroinflammation. We have previously reported that HIV-1 Tat can induce mitochondrial hyperpolarization in cortical neurons, thus compromising the ability of the neuron to buffer calcium and sustain energy production for normal synaptic communication. In this report, we demonstrate that Tat induces rapid loss of ER calcium mediated by the ryanodine receptor (RyR, followed by the unfolded protein response (UPR and pathologic dilatation of the ER in cortical neurons in vitro. RyR antagonism attenuated both Tat-mediated mitochondrial hyperpolarization and UPR induction. Delivery of Tat to murine CNS in vivo also leads to long-lasting pathologic ER dilatation and mitochondrial morphologic abnormalities. Finally, we performed ultrastructural studies that demonstrated mitochondria with abnormal morphology and dilated endoplasmic reticulum (ER in brain tissue of patients with HIV-1 inflammation and neurodegeneration. Collectively, these data suggest that abnormal RyR signaling mediates the neuronal UPR with failure of mitochondrial energy metabolism, and is a critical locus for the neuropathogenesis of HIV-1 in the CNS.

  18. Role of Histidine 547 of Human Dopamine Transporter in Molecular Interaction with HIV-1 Tat and Dopamine Uptake.

    Science.gov (United States)

    Yuan, Yaxia; Quizon, Pamela M; Sun, Wei-Lun; Yao, Jianzhuang; Zhu, Jun; Zhan, Chang-Guo

    2016-06-02

    HIV-1 Tat plays an important role in HIV-associated neurocognitive disorders (HAND) by disrupting neurotransmission including dopamine uptake by human dopamine transporter (hDAT). Previous studies have demonstrated that HIV-1 Tat directly binds to hDAT and some amino-acid mutations that attenuate the hDAT-Tat binding also significantly decreased dopamine uptake activity of hDAT. This combined computational-experimental study demonstrates that histidine-547 (H547) of hDAT plays a crucial role in the hDAT-Tat binding and dopamine uptake by hDAT, and that the H547A mutation can not only considerably attenuate Tat-induced inhibition of dopamine uptake, but also significantly increase the Vmax of hDAT for dopamine uptake. The finding of such an unusual hDAT mutant capable of both increasing the Vmax of hDAT for dopamine uptake and disrupting the hDAT-Tat binding may provide an exciting knowledge basis for development of novel concepts for therapeutic treatment of the HAND.

  19. The 73 kDa subunit of the CPSF complex binds to the HIV-1 LTR promoter and functions as a negative regulatory factor that is inhibited by the HIV-1 Tat protein.

    Science.gov (United States)

    de la Vega, Laureano; Sánchez-Duffhues, Gonzalo; Fresno, Manuel; Schmitz, M Lienhard; Muñoz, Eduardo; Calzado, Marco A

    2007-09-14

    Gene expression in eukaryotes requires the post-transcriptional cleavage of mRNA precursors into mature mRNAs. The cleavage and polyadenylation specificity factor (CPSF) is critical for this process and its 73 kDa subunit (CPSF-73) mediates cleavage coupled to polyadenylation and histone pre-mRNA processing. Using CPSF-73 over-expression and siRNA-mediated knockdown experiments, this study identifies CPSF-73 as an important regulatory protein that represses the basal transcriptional activity of the HIV-1 LTR promoter. Similar results were found with over-expression of the CPSF-73 homologue RC-68, but not with CPSF 100 kDa subunit (CPSF-100) and RC-74. Chromatin immunoprecipitation assays revealed the physical interaction of CPSF-73 with the HIV-1 LTR promoter. Further experiments revealed indirect CPSF-73 binding to the region between -275 to -110 within the 5' upstream region. Functional assays revealed the importance for the 5' upstream region (-454 to -110) of the LTR for CPSF-73-mediated transcription repression. We also show that HIV-1 Tat protein interacts with CPSF-73 and counteracts its repressive activity on the HIV-1 LTR promoter. Our results clearly show a novel function for CPSF-73 and add another candidate protein for explaining the molecular mechanisms underlying HIV-1 latency.

  20. Fractalkine/CX3CL1 protects striatal neurons from synergistic morphine and HIV-1 Tat-induced dendritic losses and death

    Directory of Open Access Journals (Sweden)

    Suzuki Masami

    2011-11-01

    Full Text Available Abstract Background Fractalkine/CX3CL1 and its cognate receptor CX3CR1 are abundantly expressed in the CNS. Fractalkine is an unusual C-X3-C motif chemokine that is important in neuron-microglial communication, a co-receptor for HIV infection, and can be neuroprotective. To assess the effects of fractalkine on opiate-HIV interactive neurotoxicity, wild-type murine striatal neurons were co-cultured with mixed glia from the striata of wild-type or Cx3cr1 knockout mice ± HIV-1 Tat and/or morphine. Time-lapse digital images were continuously recorded at 20 min intervals for up to 72 h using computer-aided microscopy to track the same cells repeatedly. Results Co-exposure to Tat and morphine caused synergistic increases in neuron death, dendritic pruning, and microglial motility as previously reported. Exogenous fractalkine prevented synergistic Tat and morphine-induced dendritic losses and neuron death even though the inflammatory mediator TNF-α remained significantly elevated. Antibody blockade of CX3CR1 mimicked the toxic effects of morphine plus Tat, but did not add to their toxicity; while fractalkine failed to protect wild-type neurons co-cultured with Cx3cr1-/--null glia against morphine and Tat toxicity. Exogenous fractalkine also normalized microglial motility, which is elevated by Tat and morphine co-exposure, presumably limiting microglial surveillance that may lead to toxic effects on neurons. Fractalkine immunofluorescence was expressed in neurons and to a lesser extent by other cell types, whereas CX3CR1 immunoreactivity or GFP fluorescence in cells cultured from the striatum of Cx3cr1-/- (Cx3cr1GFP/GFP mice were associated with microglia. Immunoblotting shows that fractalkine levels were unchanged following Tat and/or morphine exposure and there was no increase in released fractalkine as determined by ELISA. By contrast, CX3CR1 protein levels were markedly downregulated. Conclusions The results suggest that deficits in fractalkine

  1. In Vivo Microdialysis in Awake, Freely Moving Rats Demonstrates HIV-1 Tat-Induced Alterations in Dopamine Transmission

    Science.gov (United States)

    Ferris, Mark J.; Frederick-Duus, Danielle; Fadel, Jim; Mactutus, Charles F.; Booze, Rosemarie M.

    2013-01-01

    Individuals infected with human immunodeficiency virus (HIV) may develop neuropsychological impairment, and a modest percentage may progress to HIV-associated dementia (HAD). Research using human and nonhuman, in vitro and in vivo models, demonstrates that subcortical dopamine (DA) systems may be particularly vulnerable to HIV-induced neurodegeneration. The goal of the current investigation is to provide an understanding of the extent to which the HIV-1 protein Tat induces alterations in striatal DA transmission using in vivo brain microdialysis in awake, freely moving rats. The current study was designed to investigate Tat-induced neuronal dysfunction between 24-h and 48-h post-Tat administration, and demonstrates a reduction in evoked DA for the Tat-treated group relative to vehicle-treated group at 24 and 48 h. The Tat-induced reduction of DA overflow by 24 h suggests dysfunction of nerve terminals, and a compromised DA system in Tat-treated animals. Furthermore, the current study provides direct support for HIV-associated decline of DA function at a systemic level, helping to characterize the functional outcome of the relatively large amount of research on the molecular and behavioral levels of HIV-induced neurotoxicity. This initial study may provide additional characteristics of Tat-induced neuronal dysfunction to inform research on therapeutic intervention, and it provides a springboard for future in vivo research currently needed in the field. PMID:19086089

  2. Expression of an RNA glycosidase inhibits HIV-1 transactivation of transcription.

    Science.gov (United States)

    Kutky, Meherzad; Hudak, Katalin A

    2017-09-01

    HIV-1 transcription is primarily controlled by the virally encoded Tat protein and its interaction with the viral TAR RNA element. Specifically, binding of a Tat-containing complex to TAR recruits cellular factors that promote elongation of the host RNA polymerase engaging the viral DNA template. Disruption of this interaction halts viral RNA transcription. In this study, we investigated the effect of pokeweed antiviral protein (PAP), an RNA glycosidase (EC#: 3.2.2.22) synthesized by the pokeweed plant ( Phytolacca americana ), on transcription of HIV-1 mRNA. We show that co-expression of PAP with a proviral clone in culture cells resulted in a Tat-dependent decrease in viral mRNA levels. PAP reduced HIV-1 transcriptional activity by inhibiting Tat protein synthesis. The effects of PAP expression on host factors AP-1, NF-κB and SP-1, which modulate HIV-1 transcription by binding to the viral LTR, were also investigated. Only AP-1 showed a modest JNK pathway-dependent increase in activity in the presence of PAP; however, this activation was not sufficient to significantly enhance transcription from a partial viral LTR containing AP-1 binding sites. Therefore, the primary effect of PAP on HIV-1 transcription is to reduce viral RNA synthesis by decreasing the abundance of Tat. These findings provide a mechanistic explanation for the observed decrease in viral RNAs in cells expressing PAP and contribute to our understanding of the antiviral effects of this plant protein. ©2017 The Author(s).

  3. The effects of CpG-ODNs and Chitosan adjuvants on the elicitation of immune responses induced by the HIV-1-Tat-based candidate vaccines in mice.

    Science.gov (United States)

    Alipour, Samira; Mahdavi, Atiyeh; Abdoli, Asghar

    2017-03-01

    HIV1-Tat-based vaccines could elicit broad, durable and neutralizing immune responses and are considered as potential AIDS vaccines. The present study aims to formulate CpG-ODNs adjuvant and Chitosan with Tat protein to enhance the immunogenicity of HIV-1-Tat-based candidate vaccines and to investigate their efficacies in mice. To this end, we added CpG-ODNs, Chitosan and Alum as adjuvants to the Tat-based candidate vaccine formulations. Then, we compared frequency and magnitude of both humoral and cellular immune responses from mice immunized with the adjuvant-formulated Tat candidate vaccines against those obtained from mice immunized with recombinant Tat protein alone. Mice were subcutaneously immunized three times at 2-week intervals with the candidate vaccines. Measurements of anti-Tat immune responses showed that all vaccinated groups had a good immunity compared to the control groups and developed high levels of both humoral and cellular responses. However, immunized mice with CpG-ODNs, and Chitosan-adjuvanted Tat vaccines elicited stronger T-cell responses (both humoral and cellular immunity) compared to the others. These data suggest that co-administration of recombinant Tat protein with CpG-ODNs and Chitosan may serve as a potential formulation for enhancing of the Tat vaccine-induced immunity and might have effects on shaping Th polarization induced by HIV1-Tat protein vaccines. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. HIV-1 Tat-induced microgliosis and synaptic damage via interactions between peripheral and central myeloid cells.

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    Shao-Ming Lu

    Full Text Available Despite the ability of combination antiretroviral treatment (cART to reduce viral burden to nearly undetectable levels in cerebrospinal fluid and serum, HIV-1 associated neurocognitive disorders (HAND continue to persist in as many as half the patients living with this disease. There is growing consensus that the actual substrate for HAND is destruction of normal synaptic architecture but the sequence of cellular events that leads to this outcome has never been resolved. To address whether central vs. peripheral myeloid lineage cells contribute to synaptic damage during acute neuroinflammation we injected a single dose of the HIV-1 transactivator of transcription protein (Tat or control vehicle into hippocampus of wild-type or chimeric C57Bl/6 mice genetically marked to distinguish infiltrating and resident immune cells. Between 8-24 hr after injection of Tat, invading CD11b(+ and/or myeloperoxidase-positive leukocytes with granulocyte characteristics were found to engulf both microglia and synaptic structures, and microglia reciprocally engulfed invading leukocytes. By 24 hr, microglial processes were also seen ensheathing dendrites, followed by inclusion of synaptic elements in microglia 7 d after Tat injection, with a durable microgliosis lasting at least 28 d. Thus, central nervous system (CNS exposure to Tat induces early activation of peripheral myeloid lineage cells with phagocytosis of synaptic elements and reciprocal microglial engulfment of peripheral leukocytes, and enduring microgliosis. Our data suggest that a single exposure to a foreign antigen such as HIV-1 Tat can lead to long-lasting disruption of normal neuroimmune homeostasis with deleterious consequences for synaptic architecture, and further suggest a possible mechanism for enduring neuroinflammation in the absence of productive viral replication in the CNS.

  5. Neoflavonoids as Inhibitors of HIV-1 Replication by Targeting the Tat and NF-κB Pathways

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    Dionisio A. Olmedo

    2017-02-01

    Full Text Available Twenty-eight neoflavonoids have been prepared and evaluated in vitro against HIV-1. Antiviral activity was assessed on MT-2 cells infected with viral clones carrying the luciferase reporter gene. Inhibition of HIV transcription and Tat function were tested on cells stably transfected with the HIV-LTR and Tat protein. Seven 4-phenylchromen-2-one derivatives showed HIV transcriptional inhibitory activity but only the phenylchrome-2-one 10 inhibited NF-κB and displayed anti-Tat activity simultaneously. Compounds 10, 14, and 25, inhibited HIV replication in both targets at concentrations <25 μM. The assays of these synthetic 4-phenylchromen-2-ones may aid in the investigation of some aspects of the anti-HIV activity of such compounds and could serve as a scaffold for designing better anti-HIV compounds, which may lead to a potential anti-HIV therapeutic drug.

  6. Effect of HIV-1-related protein expression on cardiac and skeletal muscles from transgenic rats

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    Guidot David M

    2008-04-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 infection and the consequent acquired immunodeficiency syndrome (AIDS has protean manifestations, including muscle wasting and cardiomyopathy, which contribute to its high morbidity. The pathogenesis of these myopathies remains partially understood, and may include nutritional deficiencies, biochemical abnormalities, inflammation, and other mechanisms due to viral infection and replication. Growing evidence has suggested that HIV-1-related proteins expressed by the host in response to viral infection, including Tat and gp120, may also be involved in the pathophysiology of AIDS, particularly in cells or tissues that are not directly infected with HIV-1. To explore the potentially independent effects of HIV-1-related proteins on heart and skeletal muscles, we used a transgenic rat model that expresses several HIV-1-related proteins (e.g., Tat, gp120, and Nef. Outcome measures included basic heart and skeletal muscle morphology, glutathione metabolism and oxidative stress, and gene expressions of atrogin-1, muscle ring finger protein-1 (MuRF-1 and Transforming Growth Factor-β1 (TGFβ1, three factors associated with muscle catabolism. Results Consistent with HIV-1 associated myopathies in humans, HIV-1 transgenic rats had increased relative heart masses, decreased relative masses of soleus, plantaris and gastrocnemius muscles, and decreased total and myosin heavy chain type-specific plantaris muscle fiber areas. In both tissues, the levels of cystine (Cyss, the oxidized form of the anti-oxidant cysteine (Cys, and Cyss:Cys ratios were significantly elevated, and cardiac tissue from HIV-1 transgenic rats had altered glutathione metabolism, all reflective of significant oxidative stress. In HIV-1 transgenic rat hearts, MuRF-1 gene expression was increased. Further, HIV-1-related protein expression also increased atrogin-1 (~14- and ~3-fold and TGFβ1 (~5-fold and ~3-fold in heart and

  7. An attenuated herpes simplex virus type 1 (HSV1 encoding the HIV-1 Tat protein protects mice from a deadly mucosal HSV1 challenge.

    Directory of Open Access Journals (Sweden)

    Mariaconcetta Sicurella

    Full Text Available Herpes simplex virus types 1 and 2 (HSV1 and HSV2 are common infectious agents in both industrialized and developing countries. They cause recurrent asymptomatic and/or symptomatic infections, and life-threatening diseases and death in newborns and immunocompromised patients. Current treatment for HSV relies on antiviral medications, which can halt the symptomatic diseases but cannot prevent the shedding that occurs in asymptomatic patients or, consequently, the spread of the viruses. Therefore, prevention rather than treatment of HSV infections has long been an area of intense research, but thus far effective anti-HSV vaccines still remain elusive. One of the key hurdles to overcome in anti-HSV vaccine development is the identification and effective use of strategies that promote the emergence of Th1-type immune responses against a wide range of epitopes involved in the control of viral replication. Since the HIV1 Tat protein has several immunomodulatory activities and increases CTL recognition of dominant and subdominant epitopes of heterologous antigens, we generated and assayed a recombinant attenuated replication-competent HSV1 vector containing the tat gene (HSV1-Tat. In this proof-of-concept study we show that immunization with this vector conferred protection in 100% of mice challenged intravaginally with a lethal dose of wild-type HSV1. We demonstrate that the presence of Tat within the recombinant virus increased and broadened Th1-like and CTL responses against HSV-derived T-cell epitopes and elicited in most immunized mice detectable IgG responses. In sharp contrast, a similarly attenuated HSV1 recombinant vector without Tat (HSV1-LacZ, induced low and different T cell responses, no measurable antibody responses and did not protect mice against the wild-type HSV1 challenge. These findings strongly suggest that recombinant HSV1 vectors expressing Tat merit further investigation for their potential to prevent and/or contain HSV1

  8. Tat peptide-mediated soluble expression of the membrane protein LSECtin-CRD in Escherichia coli.

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    Guofu Dong

    Full Text Available The human liver and lymph node sinusoidal endothelial cell C-type lectin (hLSECtin, a type II integral membrane protein, containing a Ca(2+-dependent carbohydrate recognition domain (CRD, has a well-established biological activity, yet its three-dimensional structure is unknown due to low expression yields and aggregation into inclusion bodies. Previous study has demonstrated that the HIV-1 virus-encoded Tat peptide ('YGRKKRRQRRR' can increase the yields and the solubility of heterologous proteins. However, whether the Tat peptide could promote the high-yield and soluble expression of membrane proteins in Escherichia coli is not known. Therefore, the prokaryotic expression vector pET28b-Tat-hLSECtin-CRD (using pET28b and pET28b-hLSECtin-CRD as controls was constructed, and transformed into E. coli BL21 (DE3 cells and induced with isopropyl-β-d-thiogalactoside (IPTG followed with identifying by SDS-PAGE and Western blot. Subsequently, the bacterial subcellular structure, in which overexpressed the heterologous proteins Tat-hLSECtin-CRD and Tat-free hLSECtin-CRD, was analyzed by transmission electron microscope (TEM respectively, and the mannose-binding activity of Tat-hLSECtin-CRD was also determined. Expectedly, the solubility of Tat-LSECtin-CRD significantly increased compared to Tat-free LSECtin-CRD (**p < 0.01 with prolonged time, and the Tat-LSECtin-CRD had a significant mannose-binding activity. The subcellular structure analysis indicated that the bacterial cells overexpressed Tat-hLSECtin-CRD exhibited denser region compared with controls, while dot denser region aggregated in the two ends of bacterial cells overexpressed Tat-free hLSECtin-CRD. This study provided a novel method for improving the soluble expression of membrane proteins in prokaryotic systems by fusion with the Tat peptide, which may be potentially expanded to the expression of other membrane proteins.

  9. HIV-1 Tat promotes Kaposi's sarcoma-associated herpesvirus (KSHV vIL-6-induced angiogenesis and tumorigenesis by regulating PI3K/PTEN/AKT/GSK-3β signaling pathway.

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    Feng Zhou

    Full Text Available Kaposi's sarcoma (KS-associated herpesvirus (KSHV is etiologically associated with KS, the most common AIDS-related malignancy. KS is characterized by vast angiogenesis and hyperproliferative spindle cells. We have previously reported that HIV-1 Tat can trigger KSHV reactivation and accelerate Kaposin A-induced tumorigenesis. Here, we explored Tat promotion of KSHV vIL-6-induced angiogenesis and tumorigenesis. Tat promotes vIL-6-induced cell proliferation, cellular transformation, vascular tube formation and VEGF production in culture. Tat enhances vIL-6-induced angiogenesis and tumorigenesis of fibroblasts and human endothelial cells in a chicken chorioallantoic membrane (CAM model. In an allograft model, Tat promotes vIL-6-induced tumorigenesis and expression of CD31, CD34, SMA, VEGF, b-FGF, and cyclin D1. Mechanistic studies indicated Tat activates PI3K and AKT, and inactivates PTEN and GSK-3β in vIL-6 expressing cells. LY294002, a specific inhibitor of PI3K, effectively impaired Tat's promotion of vIL-6-induced tumorigenesis. Together, these results provide the first evidence that Tat might contribute to KS pathogenesis by synergizing with vIL-6, and identify PI3K/AKT pathway as a potential therapeutic target in AIDS-related KS patients.

  10. Insights into HIV-1 proviral transcription from integrative structure and dynamics of the Tat:AFF4:P-TEFb:TAR complex

    Science.gov (United States)

    Schulze-Gahmen, Ursula; Echeverria, Ignacia; Stjepanovic, Goran; Bai, Yun; Lu, Huasong; Schneidman-Duhovny, Dina; Doudna, Jennifer A; Zhou, Qiang; Sali, Andrej; Hurley, James H

    2016-01-01

    HIV-1 Tat hijacks the human superelongation complex (SEC) to promote proviral transcription. Here we report the 5.9 Å structure of HIV-1 TAR in complex with HIV-1 Tat and human AFF4, CDK9, and CycT1. The TAR central loop contacts the CycT1 Tat-TAR recognition motif (TRM) and the second Tat Zn2+-binding loop. Hydrogen-deuterium exchange (HDX) shows that AFF4 helix 2 is stabilized in the TAR complex despite not touching the RNA, explaining how it enhances TAR binding to the SEC 50-fold. RNA SHAPE and SAXS data were used to help model the extended (Tat Arginine-Rich Motif) ARM, which enters the TAR major groove between the bulge and the central loop. The structure and functional assays collectively support an integrative structure and a bipartite binding model, wherein the TAR central loop engages the CycT1 TRM and compact core of Tat, while the TAR major groove interacts with the extended Tat ARM. DOI: http://dx.doi.org/10.7554/eLife.15910.001 PMID:27731797

  11. Determining the Functions of HIV-1 Tat and a Second Magnesium Ion in the CDK9/Cyclin T1 Complex: A Molecular Dynamics Simulation Study.

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    Hai-Xiao Jin

    Full Text Available The current paradigm of cyclin-dependent kinase (CDK regulation based on the well-established CDK2 has been recently expanded. The determination of CDK9 crystal structures suggests the requirement of an additional regulatory protein, such as human immunodeficiency virus type 1 (HIV-1 Tat, to exert its physiological functions. In most kinases, the exact number and roles of the cofactor metal ions remain unappreciated, and the repertoire has thus gained increasing attention recently. Here, molecular dynamics (MD simulations were implemented on CDK9 to explore the functional roles of HIV-1 Tat and the second Mg2+ ion at site 1 (Mg12+. The simulations unveiled that binding of HIV-1 Tat to CDK9 not only stabilized hydrogen bonds (H-bonds between ATP and hinge residues Asp104 and Cys106, as well as between ATP and invariant Lys48, but also facilitated the salt bridge network pertaining to the phosphorylated Thr186 at the activation loop. By contrast, these H-bonds cannot be formed in CDK9 owing to the absence of HIV-1 Tat. MD simulations further revealed that the Mg12+ ion, coupled with the Mg22+ ion, anchored to the triphosphate moiety of ATP in its catalytic competent conformation. This observation indicates the requirement of the Mg12+ ion for CDK9 to realize its function. Overall, the introduction of HIV-1 Tat and Mg12+ ion resulted in the active site architectural characteristics of phosphorylated CDK9. These data highlighted the functional roles of HIV-1 Tat and Mg12+ ion in the regulation of CDK9 activity, which contributes an important complementary understanding of CDK molecular underpinnings.

  12. Efficient propagation of progressive multifocal leukoencephalopathy-type JC virus in COS-7-derived cell lines stably expressing Tat protein of human immunodeficiency virus type 1.

    Science.gov (United States)

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

    2010-12-01

    The high incidence of progressive multifocal leukoencephalopathy (PML) in AIDS patients compared with many other immunosuppressive diseases suggests that HIV-1 infection is strictly related to the activation of JC virus (JCV) propagation. In this report, propagation of PML-type JCV in COS-7-derived cell lines stably expressing HIV-1 Tat (COS-tat cells) has been examined. In COS-tat cells, production of viral particles and replication of genomic DNA were markedly increased compared to COS-7 cells, as judged by HA and real-time PCR analyses. These results demonstrate that COS-tat cells provide a useful model system for studying HIV-1 Tat-mediated propagation of PML-type JCV.

  13. Structure-based design of ligands for protein basic domains: Application to the HIV-1 Tat protein

    Science.gov (United States)

    Filikov, Anton V.; James, Thomas L.

    1998-05-01

    A methodology has been developed for designing ligands to bind a flexible basic protein domain where the structure of the domain is essentially known. It is based on an empirical binding free energy function developed for highly charged complexes and on Monte Carlo simulations in internal coordinates with both the ligand and the receptor being flexible. HIV-1 encodes a transactivating regulatory protein called Tat. Binding of the basic domain of Tat to TAR RNA is required for efficient transcription of the viral genome. The structure of a biologically active peptide containing the Tat basic RNA-binding domain is available from NMR studies. The goal of the current project is to design a ligand which will bind to that basic domain and potentially inhibit the TAR-Tat interaction. The basic domain contains six arginine and two lysine residues. Our strategy was to design a ligand for arginine first and then a superligand for the basic domain by joining arginine ligands with a linker. Several possible arginine ligands were obtained by searching the Available Chemicals Directory with DOCK 3.5 software. Phytic acid, which can potentially bind multiple arginines, was chosen as a building block for the superligand. Calorimetric binding studies of several compounds to methylguanidine and Arg-/Lys-containing peptides were performed. The data were used to develop an empirical binding free energy function for prediction of affinity of the ligands for the Tat basic domain. Modeling of the conformations of the complexes with both the superligand and the basic domain being flexible has been carried out via Biased Probability Monte Carlo (BPMC) simulations in internal coordinates (ICM 2.6 suite of programs). The simulations used parameters to ensure correct folding, i.e., consistent with the experimental NMR structure of a 25-residue Tat peptide, from a random starting conformation. Superligands for the basic domain were designed by joining together two molecules of phytic acid with

  14. HIV-1 transgene expression in rats causes oxidant stress and alveolar epithelial barrier dysfunction

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    Jacob Barbara A

    2009-02-01

    Full Text Available Abstract Background HIV-infected individuals are at increased risk for acute and chronic airway disease even though there is no evidence that the virus can infect the lung epithelium. Although HIV-related proteins including gp120 and Tat can directly cause oxidant stress and cellular dysfunction, their effects in the lung are unknown. The goal of this study was to determine the effects of HIV-1 transgene expression in rats on alveolar epithelial barrier function. Alveolar epithelial barrier function was assessed by determining lung liquid clearance in vivo and alveolar epithelial monolayer permeability in vitro. Oxidant stress in the alveolar space was determined by measuring the glutathione redox couple by high performance liquid chromatography, and the expression and membrane localization of key tight junction proteins were assessed. Finally, the direct effects of the HIV-related proteins gp120 and Tat on alveolar epithelial barrier formation and tight junction protein expression were determined. Results HIV-1 transgene expression caused oxidant stress within the alveolar space and impaired epithelial barrier function even though there was no evidence of overt inflammation within the airways. The expression and membrane localization of the tight junction proteins zonula occludens-1 and occludin were decreased in alveolar epithelial cells from HIV-1 transgenic rats. Further, treating alveolar epithelial monolayers from wild type rats in vitro with recombinant gp120 or Tat for 24 hours reproduced many of the effects on zonula occludens-1 and occludin expression and membrane localization. Conclusion Taken together, these data indicate that HIV-related proteins cause oxidant stress and alter the expression of critical tight junction proteins in the alveolar epithelium, resulting in barrier dysfunction.

  15. UV and X-ray structural studies of a 101-residue long Tat protein from a HIV-1 primary isolate and of its mutated, detoxified, vaccine candidate.

    Science.gov (United States)

    Foucault, Marine; Mayol, Katia; Receveur-Bréchot, Véronique; Bussat, Marie-Claire; Klinguer-Hamour, Christine; Verrier, Bernard; Beck, Alain; Haser, Richard; Gouet, Patrice; Guillon, Christophe

    2010-05-01

    The 101-residue long Tat protein of primary isolate 133 of the human immunodeficiency virus type 1 (HIV-1), wt-Tat(133) displays a high transactivation activity in vitro, whereas the mutant thereof, STLA-Tat(133), a vaccine candidate for HIV-1, has none. These two proteins were chemically synthesized and their biological activity was validated. Their structural properties were characterized using circular dichroism (CD), fluorescence emission, gel filtration, dynamic light scattering, and small angle X-ray scattering (SAXS) techniques. SAXS studies revealed that both proteins were extended and belong to the family of intrinsically unstructured proteins. CD measurements showed that wt-Tat(133) or STLA-Tat(133) underwent limited structural rearrangements when complexed with specific fragments of antibodies. Crystallization trials have been performed on the two forms, assuming that the Tat(133) proteins might have a better propensity to fold in supersaturated conditions, and small crystals have been obtained. These results suggest that biologically active Tat protein is natively unfolded and requires only a limited gain of structure for its function.

  16. HIV-1 Tat Protein Activates both the MyD88 and TRIF Pathways To Induce Tumor Necrosis Factor Alpha and Interleukin-10 in Human Monocytes.

    Science.gov (United States)

    Planès, Rémi; Ben Haij, Nawal; Leghmari, Kaoutar; Serrero, Manutea; BenMohamed, Lbachir; Bahraoui, Elmostafa

    2016-07-01

    In this study, we show that the HIV-1 Tat protein interacts with rapid kinetics to engage the Toll-like receptor 4 (TLR4) pathway, leading to the production of proinflammatory and anti-inflammatory cytokines. The pretreatment of human monocytes with Tat protein for 10 to 30 min suffices to irreversibly engage the activation of the TLR4 pathway, leading to the production of tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10), two cytokines strongly implicated in the chronic activation and dysregulation of the immune system during HIV-1 infection. Therefore, this study analyzed whether the HIV-1 Tat protein is able to activate these two pathways separately or simultaneously. Using three complementary approaches, including mice deficient in the MyD88, TIRAP/MAL, or TRIF adaptor, biochemical analysis, and the use of specific small interfering RNAs (siRNAs), we demonstrated (i) that Tat was able to activate both the MyD88 and TRIF pathways, (ii) the capacity of Tat to induce TIRAP/MAL degradation, (iii) the crucial role of the MyD88 pathway in the production of Tat-induced TNF-α and IL-10, (iv) a reduction but not abrogation of IL-10 and TNF-α by Tat-stimulated macrophages from mice deficient in TIRAP/MAL, and (v) the crucial role of the TRIF pathway in Tat-induced IL-10 production. Further, we showed that downstream of the MyD88 and TRIF pathways, the Tat protein activated the protein kinase C (PKC) βII isoform, the mitogen-activated protein (MAP) kinases p38 and extracellular signal-regulated kinase 1/2 (ERK1/2), and NF-κB in a TLR4-dependent manner. Collectively, our data show that by recruiting the TLR4 pathway with rapid kinetics, the HIV-1 Tat protein leads to the engagement of both the MyD88 and TRIF pathways and to the activation of PKC, MAP kinase, and NF-κB signaling to induce the production of TNF-α and IL-10. In this study, we demonstrate that by recruiting the TLR4 pathway with rapid kinetics, the HIV-1 Tat protein leads to the engagement

  17. Design and synthesis of á,á-trehalose derivatives bearing guanidino groups as inhibitors for the Tat Protein-TAR RNA interaction of HIV-1

    Institute of Scientific and Technical Information of China (English)

    Wang Min; Xu Zhidong; Tu Pengfei; Xiao Sulong; Yu Xiaolin; Yang Ming

    2004-01-01

    Replication of human immunodeficiency virus type 1 (HIV-1) requires specific interactions of Tat protein with the transactivation responsive region (TAR) RNA. Disruption of Tat-TAR RNA interaction could inhibit HIV-1 replication. Here four target compounds were designed and synthesized to bind to TAR RNA for blocking the interaction of Tat-TAR RNA. The core molecule 6,6′-diamino-6,6′ -dideoxy-á,á-trehalose was obtained from selective bromination of a,a-trehalose at C-6,6′, followed by acetylation, azide displacement, deacetylation and reduction.Coupling of the core molecule with the protected amino acid, then deprotection and guanidinylation generated 6,6′-bis(L-arginylamino)-6,6′-dideoxy-á,á-trehalose,6,6′-bisguanidino-6,6′-dideoxy-á ,á-trehalose, 6,6′-bis [((a)-guanidinobutyryl)amino]-6,6′-dideoxy-á,á-trehalose and 6,6′-bis(guanidinoacetylamino)-6,6′-dideoxy-á,á-trehalose, respectively.Their abilities to inhibit Tat-TAR RNA interaction were determined by a Tat-dependent HIV-1LTR-driven CAT assays.

  18. Sustained inhibition of HIV-1 replication by conditional expression of the E. coli-derived endoribonuclease MazF in CD4+ T cells.

    Science.gov (United States)

    Okamoto, Mika; Chono, Hideto; Kawano, Yasuhiro; Saito, Naoki; Tsuda, Hiroshi; Inoue, Koichi; Kato, Ikunoshin; Mineno, Junichi; Baba, Masanori

    2013-04-01

    Gene therapy using a Tat-dependent expression system of MazF, an ACA nucleotide sequence-specific endoribonuclease derived from Escherichia coli, in a retroviral vector appears to be an alternative approach to the treatment of human immunodeficiency virus type 1 (HIV-1) infection. MazF can cleave HIV-1 RNA, since it has more than 240 ACA sequences. Significant inhibition of viral replication, irrespective of HIV-1 strains, was observed in CD4(+) T cells that had been transduced with the MazF-expressing retroviral vector (MazF-T cells). The growth and viability of MazF-T cells were not affected by HIV-1 infection. Interestingly, the infectivity of HIV-1 produced from MazF-T cells was found to be lower than that from control CD4(+) T cells. A long-term culture experiment with HIV-1-infected cells revealed that viral replication was always lower in MazF-T cells than in CD4(+) T cells transduced with or without a control vector for more than 200 days. MazF was expressed and mainly localized in the cytoplasm of the infected cells. Unlike in CD4(+) T cells, the expression level of Tat gradually decreased rather than increased in MazF-T cells after HIV-1 infection. As a consequence, the expression level of MazF appeared to be well regulated and sustained during HIV-1 infection in MazF-T cells. Furthermore, the levels of cellular mRNA were not affected by HIV-1 infection. Thus, the Tat-dependent MazF expression system has great potential for inhibition of HIV-1 replication in vivo without apparent toxicity and may be able to avoid the emergence of resistant strains.

  19. Methamphetamine and HIV-Tat Alter Murine Cardiac DNA Methylation and Gene Expression

    Science.gov (United States)

    Koczor, Christopher A.; Fields, Earl; Jedrzejczak, Mark J.; Jiao, Zhe; Ludaway, Tomika; Russ, Rodney; Shang, Joan; Torres, Rebecca A.; Lewis, William

    2015-01-01

    This study addresses the individual and combined effects of HIV-1 and methamphetamine (N-methyl-1-phenylpropan-2-amine, METH) on cardiac dysfunction in a transgenic mouse model of HIV/AIDS. METH is abused epidemically and is frequently associated with acquisition of HIV-1 infection or AIDS. We employed microarrays to identify mRNA differences in cardiac left ventricle (LV) gene expression following METH administration (10d, 3mg/kg/d, subcutaneously) in C57Bl/6 wild-type littermates (WT) and Tat-expressing transgenic (TG) mice. Arrays identified 880 differentially expressed genes (expression fold change>1.5, p<0.05) following METH exposure, Tat expression, or both. Using pathway enrichment analysis, mRNAs encoding polypeptides for calcium signaling and contractility were altered in the LV samples. Correlative DNA methylation analysis revealed significant LV DNA methylation changes following METH exposure and Tat expression. By combining these data sets, 38 gene promoters (27 related to METH, 11 related to Tat) exhibited differences by both methods of analysis. Among those, only the promoter for CACNA1C that encodes L-type calcium channel Cav1.2 displayed DNA methylation changes concordant with its gene expression change. Quantitative PCR verified that Cav1.2 LV mRNA abundance doubled following METH. Correlative immunoblots specific for Cav1.2 revealed a 3.5-fold increase in protein abundance in METH LVs. Data implicate Cav1.2 in calcium dysregulation and hypercontractility in the murine LV exposed to METH. They suggest a pathogenetic role for METH exposure to promote LV dysfunction that outweighs Tat-induced effects. PMID:26307267

  20. Opiate addiction therapies and HIV-1 Tat: interactive effects on glial [Ca²⁺]i, oxyradical and neuroinflammatory chemokine production and correlative neurotoxicity.

    Science.gov (United States)

    Fitting, Sylvia; Zou, Shiping; El-Hage, Nazira; Suzuki, Masami; Paris, Jason J; Schier, Christina J; Rodríguez, José W; Rodriguez, Myosotys; Knapp, Pamela E; Hauser, Kurt F

    2014-01-01

    Few preclinical studies have compared the relative therapeutic efficacy of medications used to treat opiate addiction in relation to neuroAIDS. Here we compare the ability of methadone and buprenorphine, and the prototypic opiate morphine, to potentiate the neurotoxic and proinflammatory ([Ca²⁺]i, ROS, H₂O₂, chemokines) effects of HIV-1 Tat in neuronal and/or mixed-glial co-cultures. Repeated observations of neurons during 48 h exposure to combinations of Tat, equimolar concentrations (500 nM) of morphine, methadone, or buprenorphine exacerbated neurotoxicity significantly above levels seen with Tat alone. Buprenorphine alone displayed marked neurotoxicity at 500 nM, prompting additional studies of its neurotoxic effects at 5 nM and 50 nM concentrations ± Tat. In combination with Tat, buprenorphine displayed paradoxical, concentration-dependent, neurotoxic and neuroprotective actions. Buprenorphine neurotoxicity coincided with marked elevations in [Ca²⁺]i, but not increases in glial ROS or chemokine release. Tat by itself elevated the production of CCL5/RANTES, CCL4/MIP-1β, and CCL2/MCP-1. Methadone and buprenorphine alone had no effect, but methadone interacted with Tat to further increase production of CCL5/RANTES. In combination with Tat, all drugs significantly increased glial [Ca²⁺]i, but ROS was only significantly increased by co-exposure with morphine. Taken together, the increases in glial [Ca²⁺]i, ROS, and neuroinflammatory chemokines were not especially accurate predictors of neurotoxicity. Despite similarities, opiates displayed differences in their neurotoxic and neuroinflammatory interactions with Tat. Buprenorphine, in particular, was partially neuroprotective at a low concentration, which may result from its unique pharmacological profile at multiple opioid receptors. Overall, the results reveal differences among addiction medications that may impact neuroAIDS.

  1. In vitro inhibition of vesicular stomatitis virus replication by purified porcine Mx1 protein fused to HIV-1 Tat protein transduction domain (PTD).

    Science.gov (United States)

    Zhang, Xiao-min; He, Dan-Ni; Zhou, Bin; Pang, Ran; Liu, Ke; Zhao, Jin; Chen, Pu-yan

    2013-08-01

    Vesicular stomatitis virus (VSV) is the causative agent of Vesicular stomatitis (VS), a highly contagious fatal disease of human and pigs. Few effective antiviral drugs are currently available against VSV infection. Mx proteins are interferon (IFN)-induced dynamin-like GTPases present in all vertebrates with a range of antiviral activities. Previous studies have shown that the transfected cell lines expressing either porcine Mx1 or human MxA acquired a high degree of resistance to VSV. To explore the feasibility of taking porcine Mx1 protein expressed in Escherichia coli as an antiviral agent, we applied the pCold system to express this fusion protein (PTD-poMx1), which consisted of an N-terminal HIV-1 Tat protein transduction domain (PTD) and the full-length porcine Mx1, and investigated its effects on the replication of VSV in Vero cells. The results demonstrated that the purified PTD-poMx1 fusion proteins could transduct into cells after incubated for 5h and had no cytotoxic. Furthermore, plaque reduction assay, determination of TCID50, real-time PCR and Western blot analyses were carried out to confirm the antiviral activity of purified fusion proteins in VSV-infected Vero cells. Altogether, these data suggested that PTD-poMx1 fusion proteins might be applicable to inhibit VSV replication as a novel antiviral therapeutic agent.

  2. HIV-1 induces DCIR expression in CD4+ T cells.

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    Alexandra A Lambert

    Full Text Available The C-type lectin receptor DCIR, which has been shown very recently to act as an attachment factor for HIV-1 in dendritic cells, is expressed predominantly on antigen-presenting cells. However, this concept was recently challenged by the discovery that DCIR can also be detected in CD4(+ T cells found in the synovial tissue from rheumatoid arthritis (RA patients. Given that RA and HIV-1 infections share common features such as a chronic inflammatory condition and polyclonal immune hyperactivation status, we hypothesized that HIV-1 could promote DCIR expression in CD4(+ T cells. We report here that HIV-1 drives DCIR expression in human primary CD4(+ T cells isolated from patients (from both aviremic/treated and viremic/treatment naive persons and cells acutely infected in vitro (seen in both virus-infected and uninfected cells. Soluble factors produced by virus-infected cells are responsible for the noticed DCIR up-regulation on uninfected cells. Infection studies with Vpr- or Nef-deleted viruses revealed that these two viral genes are not contributing to the mechanism of DCIR induction that is seen following acute infection of CD4(+ T cells with HIV-1. Moreover, we report that DCIR is linked to caspase-dependent (induced by a mitochondria-mediated generation of free radicals and -independent intrinsic apoptotic pathways (involving the death effector AIF. Finally, we demonstrate that the higher surface expression of DCIR in CD4(+ T cells is accompanied by an enhancement of virus attachment/entry, replication and transfer. This study shows for the first time that HIV-1 induces DCIR membrane expression in CD4(+ T cells, a process that might promote virus dissemination throughout the infected organism.

  3. Differentially-Expressed Pseudogenes in HIV-1 Infection

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    Aditi Gupta

    2015-09-01

    Full Text Available 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.

  4. Human immunodeficiency virus type 1 Tat increases the expression of cleavage and polyadenylation specificity factor 73-kilodalton subunit modulating cellular and viral expression.

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    Calzado, Marco A; Sancho, Rocío; Muñoz, Eduardo

    2004-07-01

    The human immunodeficiency virus type 1 (HIV-1) Tat protein, which is essential for HIV gene expression and viral replication, is known to mediate pleiotropic effects on various cell functions. For instance, Tat protein is able to regulate the rate of transcription of host cellular genes and to interact with the signaling machinery, leading to cellular dysfunction. To study the effect that HIV-1 Tat exerts on the host cell, we identified several genes that were up- or down-regulated in tat-expressing cell lines by using the differential display method. HIV-1 Tat specifically increases the expression of the cleavage and polyadenylation specificity factor (CPSF) 73-kDa subunit (CPSF3) without affecting the expression of the 160- and 100-kDa subunits of the CPSF complex. This complex comprises four subunits and has a key function in the 3'-end processing of pre-mRNAs by a coordinated interaction with other factors. CPSF3 overexpression experiments and knockdown of the endogenous CPSF3 by mRNA interference have shown that this subunit of the complex is an important regulatory protein for both viral and cellular gene expression. In addition to the known CPSF3 function in RNA polyadenylation, we also present evidence that this protein exerts transcriptional activities by repressing the mdm2 gene promoter. Thus, HIV-1-Tat up-regulation of CPSF3 could represent a novel mechanism by which this virus increases mRNA processing, causing an increase in both cell and viral gene expression.

  5. The Role of RNA Polymerase II Elongation Control in HIV-1 Gene Expression, Replication, and Latency

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    Kyle A. Nilson

    2011-01-01

    Full Text Available HIV-1 usurps the RNA polymerase II elongation control machinery to regulate the expression of its genome during lytic and latent viral stages. After integration into the host genome, the HIV promoter within the long terminal repeat (LTR is subject to potent downregulation in a postinitiation step of transcription. Once produced, the viral protein Tat commandeers the positive transcription elongation factor, P-TEFb, and brings it to the engaged RNA polymerase II (Pol II, leading to the production of viral proteins and genomic RNA. HIV can also enter a latent phase during which factors that regulate Pol II elongation may play a role in keeping the virus silent. HIV, the causative agent of AIDS, is a worldwide health concern. It is hoped that knowledge of the mechanisms regulating the expression of the HIV genome will lead to treatments and ultimately a cure.

  6. The Tat protein of human immunodeficiency virus-1 enhances hepatitis C virus replication through interferon gamma-inducible protein-10

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    Qu Jing

    2012-04-01

    Full Text Available Abstract Background Co-infection with human immunodeficiency virus-1 (HIV-1 and hepatitis C virus (HCV is associated with faster progression of liver disease and an increase in HCV persistence. However, the mechanism by which HIV-1 accelerates the progression of HCV liver disease remains unknown. Results HIV-1/HCV co-infection is associated with increased expression of interferon gamma-induced protein-10 (IP-10 mRNA in peripheral blood mononuclear cells (PBMCs. HCV RNA levels were higher in PBMCs of patients with HIV-1/HCV co-infection than in patients with HCV mono-infection. HIV-1 Tat and IP-10 activated HCV replication in a time-dependent manner, and HIV-1 Tat induced IP-10 production. In addition, the effect of HIV-1 Tat on HCV replication was blocked by anti-IP-10 monoclonal antibody, demonstrating that the effect of HIV-1 Tat on HCV replication depends on IP-10. Taken together, these results suggest that HIV-1 Tat protein activates HCV replication by upregulating IP-10 production. Conclusions HIV-1/HCV co-infection is associated with increased expression of IP-10 mRNA and replication of HCV RNA. Furthermore, both HIV-1 Tat and IP-10 activate HCV replication. HIV-1 Tat activates HCV replication by upregulating IP-10 production. These results expand our understanding of HIV-1 in HCV replication and the mechanism involved in the regulation of HCV replication mediated by HIV-1 during co-infection.

  7. Tetherin does not significantly restrict dendritic cell-mediated HIV-1 transmission and its expression is upregulated by newly synthesized HIV-1 Nef

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    Wu Li

    2011-04-01

    Full Text Available Abstract Background Dendritic cells (DCs are among the first cells to encounter HIV-1 and play important roles in viral transmission and pathogenesis. Immature DCs allow productive HIV-1 replication and long-term viral dissemination. The pro-inflammatory factor lipopolysaccharide (LPS induces DC maturation and enhances the efficiency of DC-mediated HIV-1 transmission. Type I interferon (IFN partially inhibits HIV-1 replication and cell-cell transmission in CD4+ T cells and macrophages. Tetherin is a type I IFN-inducible restriction factor that blocks HIV-1 release and modulates CD4+ T cell-mediated cell-to-cell transmission of HIV-1. However, the role of type I IFN and tetherin in HIV-1 infection of DCs and DC-mediated viral transmission remains unknown. Results We demonstrated that IFN-alpha (IFNα-induced mature DCs restricted HIV-1 replication and trans-infection of CD4+ T cells. Tetherin expression in monocyte-derived immature DCs was undetectable or very low. High levels of tetherin were transiently expressed in LPS- and IFNα-induced mature DCs, while HIV-1 localized into distinct patches in these DCs. Knockdown of induced tetherin in LPS- or IFNα-matured DCs modestly enhanced HIV-1 transmission to CD4+ T cells, but had no significant effect on wild-type HIV-1 replication in mature DCs. Intriguingly, we found that HIV-1 replication in immature DCs induced significant tetherin expression in a Nef-dependent manner. Conclusions The restriction of HIV-1 replication and transmission in IFNα-induced mature DCs indicates a potent anti-HIV-1 response; however, high levels of tetherin induced in mature DCs cannot significantly restrict wild-type HIV-1 release and DC-mediated HIV-1 transmission. Nef-dependent tetherin induction in HIV-1-infected immature DCs suggests an innate immune response of DCs to HIV-1 infection.

  8. Characterization of the HIV-1 TAR RNA-Tat peptide and drug interactions by on-line acoustic wave sensor

    Science.gov (United States)

    Tassew, Nardos Gobena

    This thesis presents the application of the thickness shear-mode (TSM) acoustic wave sensor to the study of RNA-protein and RNA-drug interactions at the solid-liquid interface. The binding of the human immunodeficiency virus-type 1 Tat protein to the trans-activation responsive RNA element (TAR) has been studied using this sensor. Data from such measurements show that the sensor is able to discriminate between different Tat peptides derived from the parent protein based on size. The effects of mutations introduced at specific sites in the protein and RNA on the TAR-Tat binding have also been examined in detail. Reduced level of response in acoustic parameters due to mutations was observed indicating that the decrease in binding in response to site specific mutations can be acoustically detected. Data from acoustic wave sensor measurements indicate that the TAR-Tat binding is also affected by ionic strength. Both the frequency and motional resistance signals show periodic responses when varying concentrations of salt are introduced on a TAR-modified surface. The binding of the two molecules seems to be a function of the response of the nucleic acid to salt concentrations. The kinetics of binding of Tat peptides to TAR RNA and to a bulge mutant analogue (MTAR) is also examined from the rate of change of the series resonant frequency. Results from such analysis illustrate longer Tat peptides formed more stable complexes with TAR RNA and exhibited increased discrimination between mutant and wild type TAR. The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to TAR RNA and their effectiveness in preventing TAR-Tat complex formation has been studied in detail. Binding affinity is directly correlated with the inhibitory potency of these molecules and the TSM sensor shows that neomycin exhibits at least a ten fold greater affinity to TAR and that it is also a more potent inhibitor than streptomycin. The results from this research involving TAR-Tat and

  9. Cellular penetration and nuclear importation properties of {sup 111}In-labeled and {sup 123}I-labeled HIV-1 tat peptide immunoconjugates in BT-474 human breast cancer cells

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    Cornelissen, Bart [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Hu, Meiduo [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); McLarty, Kristin [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Costantini, Dan [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada); Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada); Reilly, Raymond M. [Division of Nuclear Medicine, University Health Network, Toronto, ON, M5S 3M2 (Canada) and Department of Medical Imaging, University of Toronto, Toronto, ON, M5S 3M2 (Canada) and Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, M5S 3M2 (Canada) and Toronto General Research Institute, University Health Network, Toronto, ON, M5S 3M2 (Canada)]. E-mail: raymond.reilly@utoronto.ca

    2007-01-15

    Introduction: Our objective was to compare the cell penetration and nuclear importation properties of {sup 111}In-labeled and {sup 123}I-labeled immunoconjugates (ICs) composed of 16-mer peptides (GRKKRRQRRRPPQGYG) derived from HIV-1 transactivator of transcription (tat) protein and anti-mouse IgG (mIgG) in BT-474 breast cancer (BC) cells. Methods: [{sup 111}In]tat ICs were constructed by site-specific conjugation of tat peptides to NaIO{sub 4} {sup -}-oxidized carbohydrates in the Fc domain of diethylenetriaminepentaacetic-acid-modified anti-mIgG antibodies. Immunoreactivity against mIgG was assessed in a competition assay. The kinetics of the accumulation of [{sup 111}In]anti-mIgG-tat IC and [{sup 123}I]anti-mIgG-tat ICs in BT-474 cells and the elimination of radioactivity from cells, cytoplasm or nuclei were determined. The effects of excess tat peptides or NH{sub 4}Cl (an inhibitor of endosomal acidification) on cellular uptake and nuclear importation of [{sup 111}In]anti-mIgG-tat were measured. Results: [{sup 111}In]anti-mIgG-tat was >97% radiochemically pure and exhibited preserved immunoreactivity with mIgG epitopes. [{sup 123}I]Anti-mIgG-tat penetrated BT-474 cells more rapidly than [{sup 111}In]anti-mIgG-tat ICs and achieved a 1.5-fold to a 2-fold higher uptake in cells and nuclei. Cell penetration and nuclear uptake of [{sup 111}In]anti-mIgG-tat were inhibited by excess tat peptides and NH{sub 4}Cl. Elimination of radioactivity from BT-474 cells and nuclei was more rapid and complete for {sup 123}I-labeled than for {sup 111}In-labeled anti-mIgG-tat ICs. Conclusion: Tat peptides derived from HIV-1 tat protein promoted the penetration and nuclear uptake of radioactivity following the incubation of {sup 111}In-labeled and {sup 123}I-labeled anti-mIgG antibodies with BT-474 human BC cells. {sup 111}In-labeled tat ICs are feasible for inserting radionuclides into cancer cells with potential for targeting intracellular and, particularly, nuclear epitopes for

  10. Involvement of Sp1 in Butyric Acid-Induced HIV-1 Gene Expression

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    Kenichi Imai

    2015-09-01

    Full Text Available Background/Aims: The ability of human immunodeficiency virus-1(HIV-1 to establish latent infection and its re-activation is considered critical for progression of HIV-1 infection. We previously reported that a bacterial metabolite butyric acid, acting as a potent inhibitor of histone deacetylases (HDACs, could lead to induction of HIV-1 transcription; however, the molecular mechanism remains unclear. The aim of this study was to investigate the effect of butyric acid on HIV-1 gene expression. Methods: Butyric acid-mediated HIV-1 gene expression was determined by luciferase assay and Chromatin immunoprecipitation assay. Western blot analysis and ELISA were used for the detection of HIV-1. Results: We found that Sp1 binding sites within the HIV-1 promoter are primarily involved in butyric acid-mediated HIV-1 activation. In fact, Sp1 knockdown by small interfering RNA and the Sp1 inhibitor mithramycin A abolished the effect of butyric acid. We also observed that cAMP response element-binding-binding protein (CBP was required for butyric acid-induced HIV-1 activation. Conclusions: These results suggest that butyric acid stimulates HIV-1 promoter through inhibition of the Sp1-associated HDAC activity and recruitment of CBP to the HIV-1 LTR. Our findings suggest that Sp1 should be considered as one of therapeutic targets in anti-viral therapy against HIV-1 infection aggravated by butyric acid-producing bacteria.

  11. Thermodynamic studies of a series of homologous HIV-1 TAR RNA ligands reveal that loose binders are stronger Tat competitors than tight ones.

    Science.gov (United States)

    Pascale, Lise; Azoulay, Stéphane; Di Giorgio, Audrey; Zenacker, Laura; Gaysinski, Marc; Clayette, Pascal; Patino, Nadia

    2013-06-01

    RNA is a major drug target, but the design of small molecules that modulate RNA function remains a great challenge. In this context, a series of structurally homologous 'polyamide amino acids' (PAA) was studied as HIV-1 trans-activating response (TAR) RNA ligands. An extensive thermodynamic study revealed the occurence of an enthalpy-entropy compensation phenomenon resulting in very close TAR affinities for all PAA. However, their binding modes and their ability to compete with the Tat fragment strongly differ according to their structure. Surprisingly, PAA that form loose complexes with TAR were shown to be stronger Tat competitors than those forming tight ones, and thermal denaturation studies demonstrated that loose complexes are more stable than tight ones. This could be correlated to the fact that loose and tight ligands induce distinct RNA conformational changes as revealed by circular dichroism experiments, although nuclear magnetic resonance (NMR) experiments showed that the TAR binding site is the same in all cases. Finally, some loose PAA also display promising inhibitory activities on HIV-infected cells. Altogether, these results lead to a better understanding of RNA interaction modes that could be very useful for devising new ligands of relevant RNA targets.

  12. High levels of CC-chemokine expression and downregulated levels of CCR5 during HIV-1/HTLV-1 and HIV-1/HTLV-2 coinfections.

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    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 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 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 CCR5-positive cells were found in HIV-1/HTLV-1 coinfected after 3 days of incubation (P HIV-1/HTLV-1 group compared to HIV-1 alone (P HIV-1 via stimulation of CC-chemokines and receptors, potentially modifying CCR5/HIV-1 binding and HIV-1 progression in coinfected individuals.

  13. Inhibition of HIV-1 in Vitro by Combination of Vpr and Tat Specific Short Hairpin RNA via Lentiviral Vectors%慢病毒介导双shRNA靶向于HIV的抑制作用研究

    Institute of Scientific and Technical Information of China (English)

    郝彦哲; 滕智平; 杨怡姝; 孙晓娜; 马晶; 金孝华; 曾毅

    2013-01-01

    RNA干扰可以有效地抑制特定基因的表达,在HIV基因治疗中成为一种重要的方法.为了防止病毒逃逸株的出现,本研究分别构建了靶向于HIV-1调控蛋白基因vpr和tat的shRNA重组慢病毒载体以及含有这两种shRNA的双表达重组慢病毒载体,分别由U6和H1两种启动子启动,通过与靶向基因tat和vpr表达质粒在293T细胞中进行共转染,采用荧光定量PCR方法测定细胞内靶向基因的表达丰度,结果显示双表达shRNA的重组慢病毒载体对vpr和tat的表达抑制率分别可以达到89.20%和62.00%.与pNL4-3病毒包装质粒共转染,P24ELISA显示plvx-vpr-tat shRNA对病毒包装产量的抑制率可以达到99.05%,比单个shRNA的抑制率都要强,HIV-1 NL4-3体外对MT4细胞攻毒实验表明双shRNA重组慢病毒载体具有很强的抑制病毒复制的能力.%Gene therapy offers the promise of curing the HIV-infected patients. Specific, potent, and sustained short hairpin RNA (shRNA)-mediated gene silencing is crucial for the successful application of RNA interference technology to therapeutic interventions. To reduce the probability of viral escape mutants, in this study, we constructed lentiviral vector containing vpr and tat shRNA, respectively, furthermore the bispecific lentiviral vector harboring vpr and tat shRNA expression cassettes from U6 pro-motor and H1 promotor was cotransfected with recombinant plasmid expressing the vpr and tat gene. The result showed that the bispecific lentiviral vector plvx-vpr-tatshRNA could inhibit the vpr and tat effectively, with ratios of 89. 20% and 62. 00% respectively. When cotransfected with pNL4-3 in 293T cell, plvx-vpr-tatshRNA showed higher efficacy in down regulating the HIV NL4-3 packaging production than the plvx-vprshRNA or plvx-tatshRNA individually. MT4 cell clones transduced with recombinant lentiviral vectors were screened and challenged with HIV NL4-3. P24 ELISA test showed that MT4 transduced with the

  14. HIV-1 infection induces changes in expression of cellular splicing factors that regulate alternative viral splicing and virus production in macrophages

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    Purcell Damian FJ

    2008-02-01

    Full Text Available Abstract Background Macrophages are important targets and long-lived reservoirs of HIV-1, which are not cleared of infection by currently available treatments. In the primary monocyte-derived macrophage model of infection, replication is initially productive followed by a decline in virion output over ensuing weeks, coincident with a decrease in the levels of the essential viral transactivator protein Tat. We investigated two possible mechanisms in macrophages for regulation of viral replication, which appears to be primarily regulated at the level of tat mRNA: 1 differential mRNA stability, used by cells and some viruses for the rapid regulation of gene expression and 2 control of HIV-1 alternative splicing, which is essential for optimal viral replication. Results Following termination of transcription at increasing times after infection in macrophages, we found that tat mRNA did indeed decay more rapidly than rev or nef mRNA, but with similar kinetics throughout infection. In addition, tat mRNA decayed at least as rapidly in peripheral blood lymphocytes. Expression of cellular splicing factors in uninfected and infected macrophage cultures from the same donor showed an inverse pattern over time between enhancing factors (members of the SR family of RNA binding proteins and inhibitory factors (members of the hnRNP family. While levels of the SR protein SC35 were greatly up-regulated in the first week or two after infection, hnRNPs of the A/B and H groups were down-regulated. Around the peak of virus production in each culture, SC35 expression declined to levels in uninfected cells or lower, while the hnRNPs increased to control levels or above. We also found evidence for increased cytoplasmic expression of SC35 following long-term infection. Conclusion While no evidence of differential regulation of tat mRNA decay was found in macrophages following HIV-1 infection, changes in the balance of cellular splicing factors which regulate alternative

  15. Therapeutic immunization with HIV-1 Tat reduces immune activation and loss of regulatory T-cells and improves immune function in subjects on HAART.

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    Barbara Ensoli

    Full Text Available UNLABELLED: Although HAART suppresses HIV replication, it is often unable to restore immune homeostasis. Consequently, non-AIDS-defining diseases are increasingly seen in treated individuals. This is attributed to persistent virus expression in reservoirs and to cell activation. Of note, in CD4(+ T cells and monocyte-macrophages of virologically-suppressed individuals, there is continued expression of multi-spliced transcripts encoding HIV regulatory proteins. Among them, Tat is essential for virus gene expression and replication, either in primary infection or for virus reactivation during HAART, when Tat is expressed, released extracellularly and exerts, on both the virus and the immune system, effects that contribute to disease maintenance. Here we report results of an ad hoc exploratory interim analysis (up to 48 weeks on 87 virologically-suppressed HAART-treated individuals enrolled in a phase II randomized open-label multicentric clinical trial of therapeutic immunization with Tat (ISS T-002. Eighty-eight virologically-suppressed HAART-treated individuals, enrolled in a parallel prospective observational study at the same sites (ISS OBS T-002, served for intergroup comparison. Immunization with Tat was safe, induced durable immune responses, and modified the pattern of CD4(+ and CD8(+ cellular activation (CD38 and HLA-DR together with reduction of biochemical activation markers and persistent increases of regulatory T cells. This was accompanied by a progressive increment of CD4(+ T cells and B cells with reduction of CD8(+ T cells and NK cells, which were independent from the type of antiretroviral regimen. Increase in central and effector memory and reduction in terminally-differentiated effector memory CD4(+ and CD8(+ T cells were accompanied by increases of CD4(+ and CD8(+ T cell responses against Env and recall antigens. Of note, more immune-compromised individuals experienced greater therapeutic effects. In contrast, these changes

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

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    Gwenola Manic

    Full Text Available 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.

  17. Sialoadhesin expressed on IFN-induced monocytes binds HIV-1 and enhances infectivity.

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    Hans Rempel

    Full Text Available BACKGROUND: HIV-1 infection dysregulates the immune system and alters gene expression in circulating monocytes. Differential gene expression analysis of CD14(+ monocytes from subjects infected with HIV-1 revealed increased expression of sialoadhesin (Sn, CD169, Siglec 1, a cell adhesion molecule first described in a subset of macrophages activated in chronic inflammatory diseases. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed sialoadhesin expression on CD14(+ monocytes by flow cytometry and found significantly higher expression in subjects with elevated viral loads compared to subjects with undetectable viral loads. In cultured CD14(+ monocytes isolated from healthy individuals, sialoadhesin expression was induced by interferon-alpha and interferon-gamma but not tumor necrosis factor-alpha. Using a stringent binding assay, sialoadhesin-expressing monocytes adsorbed HIV-1 through interaction with the sialic acid residues on the viral envelope glycoprotein gp120. Furthermore, monocytes expressing sialoadhesin facilitated HIV-1 trans infection of permissive cells, which occurred in the absence of monocyte self-infection. CONCLUSIONS/SIGNIFICANCE: Increased sialoadhesin expression on CD14(+ monocytes occurred in response to HIV-1 infection with maximum expression associated with high viral load. We show that interferons induce sialoadhesin in primary CD14(+ monocytes, which is consistent with an antiviral response during viremia. Our findings suggest that circulating sialoadhesin-expressing monocytes are capable of binding HIV-1 and effectively delivering virus to target cells thereby enhancing the distribution of HIV-1. Sialoadhesin could disseminate HIV-1 to viral reservoirs during monocyte immunosurveillance or migration to sites of inflammation and then facilitate HIV-1 infection of permissive cells.

  18. Survival of the fittest: positive selection of CD4+ T cells expressing a membrane-bound fusion inhibitor following HIV-1 infection.

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    Janine Kimpel

    Full Text Available Although a variety of genetic strategies have been developed to inhibit HIV replication, few direct comparisons of the efficacy of these inhibitors have been carried out. Moreover, most studies have not examined whether genetic inhibitors are able to induce a survival advantage that results in an expansion of genetically-modified cells following HIV infection. We evaluated the efficacy of three leading genetic strategies to inhibit HIV replication: 1 an HIV-1 tat/rev-specific small hairpin (sh RNA; 2 an RNA antisense gene specific for the HIV-1 envelope; and 3 a viral entry inhibitor, maC46. In stably transduced cell lines selected such that >95% of cells expressed the genetic inhibitor, the RNA antisense envelope and viral entry inhibitor maC46 provided the strongest inhibition of HIV-1 replication. However, when mixed populations of transduced and untransduced cells were challenged with HIV-1, the maC46 fusion inhibitor resulted in highly efficient positive selection of transduced cells, an effect that was evident even in mixed populations containing as few as 1% maC46-expressing cells. The selective advantage of the maC46 fusion inhibitor was also observed in HIV-1-infected cultures of primary T lymphocytes as well as in HIV-1-infected humanized mice. These results demonstrate robust inhibition of HIV replication with the fusion inhibitor maC46 and the antisense Env inhibitor, and importantly, a survival advantage of cells expressing the maC46 fusion inhibitor both in vitro and in vivo. Evaluation of the ability of genetic inhibitors of HIV-1 replication to confer a survival advantage on genetically-modified cells provides unique information not provided by standard techniques that may be important in the in vivo efficacy of these genes.

  19. Expression, purification and characterization of a full-length recombinant HIV-1 Vpu from inclusion bodies.

    Science.gov (United States)

    Njengele, Zikhona; Kleynhans, Ronel; Sayed, Yasien; Mosebi, Salerwe

    2016-12-01

    Vpu is one of four accessory proteins encoded by human immunodeficiency virus type I (HIV-1). Vpu modulates the expression of several cellular restriction factors within the HIV-1 infected cell including CD4, CD74, the bone marrow stromal antigen 2 (BST-2) and NK-T-and-B antigen. The interaction of HIV-1 Vpu with these proteins interferes with the innate immune response directed against HIV-1; thereby promoting viral persistence. The involvement of HIV-1 Vpu in manipulating the cellular environment in ways that favor viral replication makes it an attractive target for anti-HIV drug intervention. This paper describes the over-expression and purification of a soluble HIV-1 Vpu from inclusion bodies by ion-exchange chromatography, allowing production of 6 mg of highly purified protein (>95% purity) per 10 mg of pelleted cells obtained from 1 L of bacterial culture. Far-UV circular dichroism showed that the recombinant protein is folded and retained its secondary structure. Moreover, using ELISA, known HIV-1 Vpu binding partners, BST-2 and CD74, showed that the refolded purified protein is functional or at least assumes a conformation that is capable of binding these putative binding partners. To our knowledge, this is the first report of the purification and successful solubilization of full-length, wild-type HIV-1 Vpu from inclusion bodies in Escherichia coli. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Recombinant expression of tatABC and tatAC results in the formation of interacting cytoplasmic TatA tubes in Escherichia coli.

    Science.gov (United States)

    Berthelmann, Felix; Mehner, Denise; Richter, Silke; Lindenstrauss, Ute; Lünsdorf, Heinrich; Hause, Gerd; Brüser, Thomas

    2008-09-12

    The twin-arginine translocation (Tat) system of bacteria and plant plastids serves to translocate folded proteins across energized biological membranes. In Escherichia coli, the three components TatA, TatB, and TatC mediate this membrane passage. Here we demonstrate that TatA can assemble to form clusters of tube-like structures in vivo. While the presence of TatC is essential for their formation, TatB is not required. The TatA tubes have uniform outer and inner diameters of about 11.5 nm and 6.7 nm, respectively. They align to form a crystalline-like structure in which each tube is surrounded by six TatA tubes. The tube structures become easily detectable even at only a 15-fold overexpression of the tatABC genes. The TatA tubes could also be visualized by fluorescence when untagged TatA was mixed with low amounts of TatA-GFP. The structures were often found in contact with the cell poles. Because TatC is most likely polar in E. coli, as demonstrated by a RR-dependent targeting of translocation-incompatible Tat substrates to the cell poles, and because TatC is required for the formation of aligned TatA tubes, it is proposed that the TatA tubes are initiated at polarly localized TatC.

  1. Differential effect of CLK SR Kinases on HIV-1 gene expression: potential novel targets for therapy

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    Dobson Wendy

    2011-06-01

    Full Text Available Abstract Background RNA processing plays a critical role in the replication of HIV-1, regulated in part through the action of host SR proteins. To explore the impact of modulating SR protein activity on virus replication, the effect of increasing or inhibiting the activity of the Cdc2-like kinase (CLK family of SR protein kinases on HIV-1 expression and RNA processing was examined. Results Despite their high homology, increasing individual CLK expression had distinct effects on HIV-1, CLK1 enhancing Gag production while CLK2 inhibited the virus. Parallel studies on the anti-HIV-1 activity of CLK inhibitors revealed a similar discrepant effect on HIV-1 expression. TG003, an inhibitor of CLK1, 2 and 4, had no effect on viral Gag synthesis while chlorhexidine, a CLK2, 3 and 4 inhibitor, blocked virus production. Chlorhexidine treatment altered viral RNA processing, decreasing levels of unspliced and single spliced viral RNAs, and reduced Rev accumulation. Subsequent experiments in the context of HIV-1 replication in PBMCs confirmed the capacity of chlorhexidine to suppress virus replication. Conclusions Together, these findings establish that HIV-1 RNA processing can be targeted to suppress virus replication as demonstrated by manipulating individual CLK function and identified chlorhexidine as a lead compound in the development of novel anti-viral therapies.

  2. Primary T-cells from human CD4/CCR5-transgenic rats support all early steps of HIV-1 replication including integration, but display impaired viral gene expression

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    Hermann Volker

    2007-07-01

    Full Text Available Abstract Background In vivo studies on HIV-1 pathogenesis and testing of antiviral strategies have been hampered by the lack of an immunocompetent small animal model that is highly susceptible to HIV-1 infection. Since native rodents are non-permissive, we developed transgenic rats that selectively express the HIV-1 receptor complex, hCD4 and hCCR5, on relevant target cells. These animals display a transient low-level plasma viremia after HIV-1YU-2 infection, demonstrating HIV-1 susceptibility in vivo. However, unlike macrophages, primary CD4 T-cells from double-transgenic animals fail to support viral spread ex vivo. To identify quantitative limitations or absolute blocks in this rodent species, we quantitatively assessed the efficiency of key steps in the early phase of the viral replication cycle in a side-by-side comparison in infected cell lines and primary T-cells from hCD4/hCCR5-transgenic rats and human donors. Results Levels of virus entry, HIV-1 cDNA synthesis, nuclear import, and integration into the host genome were shown to be remarkably similar in cell lines and, where technically accessible, in primary T-cells from both species. In contrast, a profound impairment at the level of early HIV gene expression was disclosed at the single-cell level in primary rat T-cells and most other rat-derived cells. Macrophages were a notable exception, possibly reflecting the unique transcriptional milieu in this evolutionarily conserved target cell of all lentiviruses. Importantly, transient trans-complementation by ex vivo nucleofection with the Tat-interacting protein Cyclin T1 of human origin markedly elevated HIV gene expression in primary rat T-cells. Conclusion This is the first study that has quantitatively determined the efficiency of consecutive steps in the HIV-1 replication cycle in infected primary HIV target cells from a candidate transgenic small animal and compared it to human cells. Unlike cells derived from mice or rabbits, rat

  3. Mycobacterium avium complex augments macrophage HIV-1 production and increases CCR5 expression.

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    Wahl, S M; Greenwell-Wild, T; Peng, G; Hale-Donze, H; Doherty, T M; Mizel, D; Orenstein, J M

    1998-10-13

    Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic infections (OI). Reciprocally, OI augment HIV-1 replication. As we have shown for Mycobacterium avium complex (MAC) and Pneumocystis carinii, macrophages infected with opportunistic pathogens and within lymphoid tissues containing OI, exhibit striking levels of viral replication. To explore potential underlying mechanisms for increased HIV-1 replication associated with coinfection, blood monocytes were exposed to MAC antigens (MAg) or viable MAC and their levels of tumor necrosis factor alpha (TNFalpha) and HIV-1 coreceptors monitored. MAC enhanced TNFalpha production in vitro, consistent with its expression in coinfected lymph nodes. Using a polyclonal antibody to the CCR5 coreceptor that mediates viral entry of macrophage tropic HIV-1, a subset of unstimulated monocytes was shown to be CCR5-positive by fluorescence-activated cell sorter analysis. After stimulation with MAg or infection with MAC, CCR5 expression was increased at both the mRNA level and on the cell surface. Up-regulation of CCR5 by MAC was not paralleled by an increase in the T cell tropic coreceptor, CXCR4. Increases in NF-kappaB, TNFalpha, and CCR5 were consistent with the enhanced production of HIV-1 in MAg-treated adherent macrophage cultures as measured by HIV-1 p24 levels. Increased CCR5 was also detected in coinfected lymph nodes as compared with tissues with only HIV-1. The increased production of TNFalpha, together with elevated expression of CCR5, provide potential mechanisms for enhanced infection and replication of HIV-1 by macrophages in OI-infected cells and tissues. Consequently, treating OI may inhibit not only the OI-induced pathology, but also limit the viral burden.

  4. An efficient procedure for the expression and purification of HIV-1 protease from inclusion bodies.

    Science.gov (United States)

    Nguyen, Hong-Loan Thi; Nguyen, Thuy Thi; Vu, Quy Thi; Le, Hang Thi; Pham, Yen; Trinh, Phuong Le; Bui, Thuan Phuong; Phan, Tuan-Nghia

    2015-12-01

    Several studies have focused on HIV-1 protease for developing drugs for treating AIDS. Recombinant HIV-1 protease is used to screen new drugs from synthetic compounds or natural substances. However, large-scale expression and purification of this enzyme is difficult mainly because of its low expression and solubility. In this study, we constructed 9 recombinant plasmids containing a sequence encoding HIV-1 protease along with different fusion tags and examined the expression of the enzyme from these plasmids. Of the 9 plasmids, pET32a(+) plasmid containing the HIV-1 protease-encoding sequence along with sequences encoding an autocleavage site GTVSFNF at the N-terminus and TEV plus 6× His tag at the C-terminus showed the highest expression of the enzyme and was selected for further analysis. The recombinant protein was isolated from inclusion bodies by using 2 tandem Q- and Ni-Sepharose columns. SDS-PAGE of the obtained HIV-1 protease produced a single band of approximately 13 kDa. The enzyme was recovered efficiently (4 mg protein/L of cell culture) and had high specific activity of 1190 nmol min(-1) mg(-1) at an optimal pH of 4.7 and optimal temperature of 37 °C. This procedure for expressing and purifying HIV-1 protease is now being scaled up to produce the enzyme on a large scale for its application.

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

    Science.gov (United States)

    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.

  6. HIV-1 tat promotes integrin-mediated HIV transmission to dendritic cells by binding Env spikes and competes neutralization by anti-HIV antibodies.

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    Paolo Monini

    Full Text Available Use of Env in HIV vaccine development has been disappointing. Here we show that, in the presence of a biologically active Tat subunit vaccine, a trimeric Env protein prevents in monkeys virus spread from the portal of entry to regional lymph nodes. This appears to be due to specific interactions between Tat and Env spikes that form a novel virus entry complex favoring R5 or X4 virus entry and productive infection of dendritic cells (DCs via an integrin-mediated pathway. These Tat effects do not require Tat-transactivation activity and are blocked by anti-integrin antibodies (Abs. Productive DC infection promoted by Tat is associated with a highly efficient virus transmission to T cells. In the Tat/Env complex the cysteine-rich region of Tat engages the Env V3 loop, whereas the Tat RGD sequence remains free and directs the virus to integrins present on DCs. V2 loop deletion, which unshields the CCR5 binding region of Env, increases Tat/Env complex stability. Of note, binding of Tat to Env abolishes neutralization of Env entry or infection of DCs by anti-HIV sera lacking anti-Tat Abs, which are seldom present in natural infection. This is reversed, and neutralization further enhanced, by HIV sera containing anti-Tat Abs such as those from asymptomatic or Tat-vaccinated patients, or by sera from the Tat/Env vaccinated monkeys. Thus, both anti-Tat and anti-Env Abs are required for efficient HIV neutralization. These data suggest that the Tat/Env interaction increases HIV acquisition and spreading, as a mechanism evolved by the virus to escape anti-Env neutralizing Abs. This may explain the low effectiveness of Env-based vaccines, which are also unlikely to elicit Abs against new Env epitopes exposed by the Tat/Env interaction. As Tat also binds Envs from different clades, new vaccine strategies should exploit the Tat/Env interaction for both preventative and therapeutic interventions.

  7. Inhibition of HIV-1 replication by small interfering RNAs directed against Glioma Pathogenesis Related Protein (GliPR expression

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    Ottmann Oliver G

    2010-03-01

    Full Text Available Abstract Background Previously, we showed that glioma pathogenesis related protein (GliPR is induced in CEM T cells upon HIV-1 infection in vitro. To examine whether GliPR plays a role as HIV dependency factor (HDF, we tested the effect of GliPR suppression by siRNA on HIV-1 replication. Results Induction of GliPR expression by HIV-1 was confirmed in P4-CCR5 cells. When GliPR was suppressed by siRNA, HIV-1 replication was significantly reduced as measured by HIV-1 transcript levels, HIV-1 p24 protein levels, and HIV-1 LTR-driven reporter gene expression, suggesting that GliPR is a cellular co-factor of HIV-1. Microarray analysis of uninfected HeLa cells following knockdown of GliPR revealed, among a multitude of gene expression alterations, a down-regulation of syndecan-1, syndecan-2, protein kinase C alpha (PRKCA, the catalytic subunit β of cAMP-dependent protein kinase (PRKACB, nuclear receptor co-activator 3 (NCOA3, and cell surface protein CD59 (protectin, all genes having relevance for HIV-1 pathology. Conclusions The up-regulation of GliPR by HIV-1 and the early significant inhibition of HIV-1 replication mediated by knockdown of GliPR reveal GliPR as an important HIV-1 dependency factor (HDF, which may be exploited for HIV-1 inhibition.

  8. RRE-dependent HIV-1 Env RNA effects on Gag protein expression, assembly and release

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    López, Claudia S., E-mail: lopezcl@ohsu.edu [Departments of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97239 (United States); Sloan, Rachel; Cylinder, Isabel [Departments of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97239 (United States); Kozak, Susan L.; Kabat, David [Biochemistry and Molecular Biology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97239 (United States); Barklis, Eric, E-mail: barklis@ohsu.edu [Departments of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97239 (United States)

    2014-08-15

    The HIV-1 Gag proteins are translated from the full-length HIV-1 viral RNA (vRNA), whereas the envelope (Env) protein is translated from incompletely spliced Env mRNAs. Nuclear export of vRNAs and Env mRNAs is mediated by the Rev accessory protein which binds to the rev-responsive element (RRE) present on these RNAs. Evidence has shown there is a direct or indirect interaction between the Gag protein, and the cytoplasmic tail (CT) of the Env protein. Our current work shows that env gene expression impacts HIV-1 Gag expression and function in two ways. At the protein level, full-length Env expression altered Gag protein expression, while Env CT-deletion proteins did not. At the RNA level, RRE-containing Env mRNA expression reduced Gag expression, processing, and virus particle release from cells. Our results support models in which Gag is influenced by the Env CT, and Env mRNAs compete with vRNAs for nuclear export. - Highlights: • At the protein level, full-length HIV-1 Env alters Gag protein expression. • HIV-1 Env RNA expression reduces Gag levels and virus release. • Env RNA effects on Gag are dependent on the RRE. • RRE-containing Env RNAs compete with vRNAs for nuclear export.

  9. p21(WAF1/CIP1 RNA expression in highly HIV-1 exposed, uninfected individuals.

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    Joshua Herbeck

    Full Text Available Some individuals remain HIV-1 antibody and PCR negative after repeated exposures to the virus, and are referred to as HIV-exposed seronegatives (HESN. However, the causes of resistance to HIV-1 infection in cases other than those with a homozygous CCR5Δ32 deletion are unclear. We hypothesized that human p21WAF1/CIP1 (a cyclin-dependent kinase inhibitor could play a role in resistance to HIV-1 infection in HESN, as p21 expression has been associated with suppression of HIV-1 in elite controllers and reported to block HIV-1 integration in cell culture. We measured p21 RNA expression in PBMC from 40 HESN and 40 low exposure HIV-1 seroconverters (LESC prior to their infection using a real-time PCR assay. Comparing the 20 HESN with the highest exposure risk (median = 111 partners/2.5 years prior to the 20 LESC with the lowest exposure risk (median = 1 partner/2.5 years prior, p21 expression trended higher in HESN in only one of two experiments (P = 0.11 vs. P = 0.80. Additionally, comparison of p21 expression in the top 40 HESN (median = 73 partners/year and lowest 40 LESC (median = 2 partners/year showed no difference between the groups (P = 0.84. There was a weak linear trend between risk of infection after exposure and increasing p21 gene expression (R2 = 0.02, P = 0.12, but again only in one experiment. Hence, if p21 expression contributes to the resistance to viral infection in HESN, it likely plays a minor role evident only in those with extremely high levels of exposure to HIV-1.

  10. Construction of Nef-positive doxycycline-dependent HIV-1 variants using bicistronic expression elements

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    Velden, Yme U. van der; Kleibeuker, Wendy; Harwig, Alex; Klaver, Bep; Siteur-van Rijnstra, Esther; Frankin, Esmay; Berkhout, Ben; Das, Atze T., E-mail: a.t.das@amc.uva.nl

    2016-01-15

    Conditionally replicating HIV-1 variants that can be switched on and off at will are attractive tools for HIV research. We previously developed a genetically modified HIV-1 variant that replicates exclusively when doxycycline (dox) is administered. The nef gene in this HIV-rtTA variant was replaced with the gene encoding the dox-dependent rtTA transcriptional activator. Because loss of Nef expression compromises virus replication in primary cells and precludes studies on Nef function, we tested different approaches to restore Nef production in HIV-rtTA. Strategies that involved translation via an EMCV or synthetic internal ribosome entry site (IRES) failed because these elements were incompatible with efficient virus replication. Fusion protein approaches with the FMDV 2A peptide and human ubiquitin were successful and resulted in genetically-stable Nef-expressing HIV-rtTA strains that replicate more efficiently in primary T-cells and human immune system (HIS) mice than Nef-deficient variants, thus confirming the positive effect of Nef on in vivo virus replication. - Highlights: • Different approaches to encode additional proteins in the HIV-1 genome were tested. • IRES translation elements are incompatible with efficient HIV-1 replication. • Ubiquitin and 2A fusion protein approaches allow efficient HIV-1 replication. • Doxycycline-controlled HIV-1 variants that encode all viral proteins were developed. • Nef stimulates HIV-rtTA replication in primary cells and human immune system mice.

  11. TAT-mediated intracellular protein delivery to primary brain cells is dependent on glycosaminoglycan expression.

    Science.gov (United States)

    Simon, Melissa J; Gao, Shan; Kang, Woo Hyeun; Banta, Scott; Morrison, Barclay

    2009-09-01

    Although some studies have shown that the cell penetrating peptide (CPP) TAT can enter a variety of cell lines with high efficiency, others have observed little or no transduction in vivo or in vitro under conditions mimicking the in vivo environment. The mechanisms underlying TAT-mediated transduction have been investigated in cell lines, but not in primary brain cells. In this study we demonstrate that transduction of a green fluorescent protein (GFP)-TAT fusion protein is dependent on glycosaminoglycan (GAG) expression in both the PC12 cell line and primary astrocytes. GFP-TAT transduced PC12 cells and did so with even higher efficiency following NGF differentiation. In cultures of primary brain cells, TAT significantly enhanced GFP delivery into astrocytes grown under different conditions: (1) monocultures grown in serum-containing medium; (2) monocultures grown in serum-free medium; (3) cocultures with neurons in serum-free medium. The efficiency of GFP-TAT transduction was significantly higher in the monocultures than in the cocultures. The GFP-TAT construct did not significantly enter neurons. Experimental modulation of GAG content correlated with alterations in TAT transduction in PC12 cells and astrocyte monocultures grown in the presence of serum. In addition, this correlation was predictive of TAT-mediated transduction in astrocyte monocultures grown in serum free medium and in coculture. We conclude that culture conditions affect cellular GAG expression, which in turn dictates TAT-mediated transduction efficiency, extending previous results from cell lines to primary cells. These results highlight the cell-type and phenotype-dependence of TAT-mediated transduction, and underscore the necessity of controlling the phenotype of the target cell in future protein engineering efforts aimed at creating more efficacious CPPs.

  12. Expression and Characterization of HIV-1 Envelope Glycoprotein in Pichia Pastoris

    Institute of Scientific and Technical Information of China (English)

    ZHAO Li-hui; YU Xiang-hui; JIANG Chun-lai; WU Yong-ge; SHEN Jia-cong; KONG Wei

    2008-01-01

    To obtain a sufficient amount of glycoprotein for further studying the structure and function of HIV-1 envelope glycoprotein, amplified and modified HIV-1 envelope glycoprotein gene which recombined subtypes(850amino acids) from Guangxi in China was inserted into Pichiapastoris expression vector pPICZaB; then the recombinant plasmid was transported into the yeast cells to induce the expression of Env protein with methanol. The results of SDS-PAGE and Western blot indicate that the envelope glycoprotein could be expressed in Pichia pastoris with productions of a 120000 glycoprotein and a 41000 glycoprotein, which showed satisfactory immunogenicity by indirect ELISA.

  13. Transcriptome sequencing of gene expression in the brain of the HIV-1 transgenic rat.

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    Ming D Li

    Full Text Available The noninfectious HIV-1 transgenic (HIV-1Tg rat was developed as a model of AIDs-related pathology and immune dysfunction by manipulation of a noninfectious HIV-1(gag-pol virus with a deleted 3-kb SphI-MscI fragment containing the 3' -region of gag and the 5' region of pol into F344 rats. Our previous studies revealed significant behavioral differences between HIV-1Tg and F344 control rats in their performance in the Morris water maze and responses to psychostimulants. However, the molecular mechanisms underlying these behavioral differences remain largely unknown. The primary goal of this study was to identify differentially expressed genes and enriched pathways affected by the gag-pol-deleted HIV-1 genome. Using RNA deep sequencing, we sequenced RNA transcripts in the prefrontal cortex, hippocampus, and striatum of HIV-1Tg and F344 rats. A total of 72 RNA samples were analyzed (i.e., 12 animals per group × 2 strains × 3 brain regions. Following deep-sequencing analysis of 50-bp paired-end reads of RNA-Seq, we used Bowtie/Tophat/Cufflinks suites to align these reads into transcripts based on the Rn4 rat reference genome and to measure the relative abundance of each transcript. Statistical analyses on each brain region in the two strains revealed that immune response- and neurotransmission-related pathways were altered in the HIV-1Tg rats, with brain region differences. Other neuronal survival-related pathways, including those encoding myelin proteins, growth factors, and translation regulators, were altered in the HIV-1Tg rats in a brain region-dependent manner. This study is the first deep-sequencing analysis of RNA transcripts associated the HIV-1Tg rat. Considering the functions of the pathways and brain regions examined in this study, our findings of abnormal gene expression patterns in HIV-1Tg rats suggest mechanisms underlying the deficits in learning and memory and vulnerability to drug addiction and other psychiatric disorders

  14. A Novel Bromodomain Inhibitor Reverses HIV-1 Latency through Specific Binding with BRD4 to Promote Tat and P-TEFb Association

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    Huachao Huang

    2017-06-01

    Full Text Available While combinatory antiretroviral therapy (cART can effectively reduce HIV-1 viremia, it cannot eliminate HIV-1 infection. In the presence of cART, viral reservoirs remain latent, impeding the cure of HIV-1/AIDS. Recently, latency-reversing agents (LRAs have been developed with the intent of purging latent HIV-1, providing an intriguing strategy for the eradication of the residual viral reservoirs. Our earlier studies show that the first-generation, methyl-triazolo bromodomain, and extra-terminal domain inhibitor (BETi, JQ1, facilitates the reversal of HIV-1 latency. BETis have emerged as a new class of compounds that are promising for this HIV-1 “shock and kill” eradication approach. However, when used as a single drug, JQ1 only modestly reverses HIV-1 latency, which complicates studying the underlining mechanisms. Meanwhile, it has been widely discussed that the induction of latent proviruses is stochastic (Ho et al., 2013. Thus, new BETis are currently under active development with focus on improving potency, ease of synthesis and structural diversity. Using fluorous-tagged multicomponent reactions, we developed a novel second-generation, 3,5-dimethylisoxazole BETi based on an imidazo[1,2-a] pyrazine scaffold, UMB-32. Furthermore, we screened 37 UMB-32 derivatives and identified that one, UMB-136, reactivates HIV-1 in multiple cell models of HIV-1 latency with better efficiency than either JQ1 or UMB-32. UMB-136 enhances HIV-1 transcription and increases viral production through the release of P-TEFb. Importantly, UMB-136 enhances the latency-reversing effects of PKC agonists (prostratin, bryostatin-1 in CD8-depleted PBMCs containing latent viral reservoirs. Our results illustrate that structurally improved BETis, such as UMB-136, may be useful as promising LRAs for HIV-1 eradication.

  15. Tat protein expression in MDBK cells does not confer susceptibility to bovine immunodeficiency virus.

    Science.gov (United States)

    Kempster, S; Collins, M E; Brownlie, J

    2002-03-01

    The ability of BIV strain R29 to infect bovine cell lines in the presence or absence of a functional lentiviral Tat protein is described. Jembrana disease virus (JDV) Tat protein was stably expressed in MDBK cells. No viral replication could be detected in this cell line after infection with BIV R29. Transfection of MDBK cells and MDBK Tat expressing cells with BIV R29 proviral DNA established that BIV R29 could not replicate in MDBK cells. Whether viral entry into MDBK cells is also a block to BIV R29 infection of MDBK cells has yet to be established.

  16. Expression profile of nicotinic acetylcholine receptor subunits in the brain of HIV-1 transgenic rats given chronic nicotine treatment.

    Science.gov (United States)

    Cao, Junran; Nesil, Tanseli; Wang, Shaolin; Chang, Sulie L; Li, Ming D

    2016-10-01

    Abuse of addictive substances, including cigarettes, is much greater in HIV-1-infected individuals than in the general population and challenges the efficiency of highly active anti-retroviral therapy (HAART). The HIV-1 transgenic (HIV-1Tg) rat, an animal model used to study drug addiction in HIV-1-infected patients on HAART, displays abnormal neurobehavioral responses to addictive substances. Given that the cholinergic system plays an essential part in the central reward circuitry, we evaluated the expression profile of nine nicotinic acetylcholine receptor (nAChR) subunit genes in the central nervous system (CNS) of HIV-1Tg rats. We found that nAChR subunits were differentially expressed in various brain regions in HIV-1Tg rats compared to F344 control rats, with more subunits altered in the ventral tegmental area (VTA) and nucleus accumbens (NAc) of the HIV-1Tg rats than in other brain regions. We also found that chronic nicotine treatment (0.4 mg/kg/day) decreased the mRNA expression of nAChR subunits α6, β3, and β4 in the VTA of HIV-1Tg rats, whereas expression of α4 and α6 subunits in the NAc increased. No such changes were observed in F344 rats. Together, our data suggest that HIV-1 proteins alter the expression of nAChRs, which may contribute to the vulnerability to cigarette smoking addiction in HIV-1 patients.

  17. Differential Expression of CD163 on Monocyte Subsets in Healthy and HIV-1 Infected Individuals

    Science.gov (United States)

    Tippett, Emma; Cheng, Wan-Jung; Westhorpe, Clare; Cameron, Paul U.; Brew, Bruce J.; Lewin, Sharon R.; Jaworowski, Anthony; Crowe, Suzanne M.

    2011-01-01

    CD163, a haptoglobin-hemoglobin (Hp-Hb) scavenger receptor, expressed by monocytes and macrophages, is important in resolution of inflammation. Age-related non-AIDS co-morbidities in HIV-infected individuals, particularly dementia and cardiovascular disease, result in part from effects of HIV-1 infection on monocyte and macrophage biology. CD163 co-expression on CD14+CD16++ monocytes has been proposed as a useful biomarker for HIV-1 disease progression and the presence of HIV associated dementia. Here we investigated CD163 expression on monocyte subsets ex vivo, on cultured macrophages, and soluble in plasma, in the setting of HIV-1 infection. Whole blood immunophenotyping revealed CD163 expression on CD14++CD16- monocytes but not on CD14+CD16++ monocytes (P = 0.004), supported by CD163 mRNA levels. Incubation with M-CSF induced CD163 protein expression on CD14+CD16++ monocytes to the same extent as CD14++CD16− monocytes. CD163 expression on CD14++CD16+ monocytes from HIV-infected subjects was significantly higher than from uninfected individuals, with a trend towards increased expression on CD14++CD16− monocytes (P = 0.019 and 0.069 respectively), which is accounted for by HIV-1 therapy including protease inhibitors. Shedding of CD163 was shown to predominantly occur from the CD14++CD16− subset after Ficoll isolation and LPS stimulation. Soluble CD163 concentration in plasma from HIV-1 infected donors was similar to HIV-1 uninfected donors. Monocyte CD163 expression in HIV-1 infected patients showed a complicated relationship with classical measures of disease progression. Our findings clarify technical issues regarding CD163 expression on monocyte subsets and further elucidates its role in HIV-associated inflammation by demonstrating that CD163 is readily lost from CD14++CD16− monocytes and induced in pro-inflammatory CD14+CD16++ monocytes by M-CSF. Our data show that all monocyte subsets are potentially capable of differentiating into CD163

  18. Differential expression of CD163 on monocyte subsets in healthy and HIV-1 infected individuals.

    Directory of Open Access Journals (Sweden)

    Emma Tippett

    Full Text Available CD163, a haptoglobin-hemoglobin (Hp-Hb scavenger receptor, expressed by monocytes and macrophages, is important in resolution of inflammation. Age-related non-AIDS co-morbidities in HIV-infected individuals, particularly dementia and cardiovascular disease, result in part from effects of HIV-1 infection on monocyte and macrophage biology. CD163 co-expression on CD14+CD16++ monocytes has been proposed as a useful biomarker for HIV-1 disease progression and the presence of HIV associated dementia. Here we investigated CD163 expression on monocyte subsets ex vivo, on cultured macrophages, and soluble in plasma, in the setting of HIV-1 infection. Whole blood immunophenotyping revealed CD163 expression on CD14++CD16- monocytes but not on CD14+CD16++ monocytes (P = 0.004, supported by CD163 mRNA levels. Incubation with M-CSF induced CD163 protein expression on CD14+CD16++ monocytes to the same extent as CD14++CD16- monocytes. CD163 expression on CD14++CD16+ monocytes from HIV-infected subjects was significantly higher than from uninfected individuals, with a trend towards increased expression on CD14++CD16- monocytes (P = 0.019 and 0.069 respectively, which is accounted for by HIV-1 therapy including protease inhibitors. Shedding of CD163 was shown to predominantly occur from the CD14++CD16- subset after Ficoll isolation and LPS stimulation. Soluble CD163 concentration in plasma from HIV-1 infected donors was similar to HIV-1 uninfected donors. Monocyte CD163 expression in HIV-1 infected patients showed a complicated relationship with classical measures of disease progression. Our findings clarify technical issues regarding CD163 expression on monocyte subsets and further elucidates its role in HIV-associated inflammation by demonstrating that CD163 is readily lost from CD14++CD16- monocytes and induced in pro-inflammatory CD14+CD16++ monocytes by M-CSF. Our data show that all monocyte subsets are potentially capable of differentiating into CD

  19. Interplay between Structure and Charge as a Key to Allosteric Modulation of Human 20S Proteasome by the Basic Fragment of HIV-1 Tat Protein.

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    Przemysław Karpowicz

    Full Text Available The proteasome is a giant protease responsible for degradation of the majority of cytosolic proteins. Competitive inhibitors of the proteasome are used against aggressive blood cancers. However, broadening the use of proteasome-targeting drugs requires new mechanistic approaches to the enzyme's inhibition. In our previous studies we described Tat1 peptide, an allosteric inhibitor of the proteasome derived from a fragment of the basic domain of HIV-Tat1 protein. Here, we attempted to dissect the structural determinants of the proteasome inhibition by Tat1. Single- and multiple- alanine walking scans were performed. Tat1 analogs with stabilized beta-turn conformation at positions 4-5 and 8-9, pointed out by the molecular dynamics modeling and the alanine scan, were synthesized. Structure of Tat1 analogs were analyzed by circular dichroism, Fourier transform infrared and nuclear magnetic resonance spectroscopy studies, supplemented by molecular dynamics simulations. Biological activity tests and structural studies revealed that high flexibility and exposed positive charge are hallmarks of Tat1 peptide. Interestingly, stabilization of a beta-turn at the 8-9 position was necessary to significantly improve the inhibitory potency.

  20. Computational analysis of HIV-1 resistance based on gene expression profiles and the virus-host interaction network.

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    Tao Huang

    Full Text Available A very small proportion of people remain negative for HIV infection after repeated HIV-1 viral exposure, which is called HIV-1 resistance. Understanding the mechanism of HIV-1 resistance is important for the development of HIV-1 vaccines and Acquired Immune Deficiency Syndrome (AIDS therapies. In this study, we analyzed the gene expression profiles of CD4+ T cells from HIV-1-resistant individuals and HIV-susceptible individuals. One hundred eighty-five discriminative HIV-1 resistance genes were identified using the Minimum Redundancy-Maximum Relevance (mRMR and Incremental Feature Selection (IFS methods. The virus protein target enrichment analysis of the 185 HIV-1 resistance genes suggested that the HIV-1 protein nef might play an important role in HIV-1 infection. Moreover, we identified 29 infection information exchanger genes from the 185 HIV-1 resistance genes based on a virus-host interaction network analysis. The infection information exchanger genes are located on the shortest paths between virus-targeted proteins and are important for the coordination of virus infection. These proteins may be useful targets for AIDS prevention or therapy, as intervention in these pathways could disrupt communication with virus-targeted proteins and HIV-1 infection.

  1. Human Herpesvirus 8 Lytic Cycle Relication and Human Immunodeficiency Virus Type 1 Tat%HIV-1 Tat蛋白对人类疱疹病毒8型复制的影响

    Institute of Scientific and Technical Information of China (English)

    卢春; 黄丽; 贾雪梅; 曾怡

    2003-01-01

    用HindⅢ将HIV-1 Tat101蛋白编码基因从pEV质粒中切出,BamHI、NotⅠ将绿色荧光蛋白(GFP)编码基因从表达质粒pcDNA3.1 + /GFP中切出,分别插入到质粒LZRSpBM N-Z中,构建成重组反转录病毒表达质粒LZRS-Tat101和LZRS- GFP.采用磷酸钙转染法将两重组质粒转染到含反转录病毒env、gal 和pol编码基因的包装细胞Phoenix(ΦNX)中,嘌呤霉素筛选获得稳定细胞系.分别收集稳定细胞系分泌的病毒上清,并感染体外培养的原发性渗出性淋巴瘤(PEL)BCBL-1细胞.收集LZRS-GFP重组病毒感染的BCBL-1细胞进行流式细胞计数,检测GFP表达水平.收集L ZRS-Tat101重组病毒感染的BCBL-1细胞,提取蛋白作Wes tern blot,检测Tat蛋白表达状况;取细胞总RNA作Nort hern blot和定量PCR,检查HHV-8次要衣壳蛋白ORF26 mRNA转录水平.重组LZRS-Tat101病毒进一步感染HL3T1 细胞(HeLa细胞包含HIV-1-LTR/CAT报告基因),收集感染细胞提取蛋白,检测CAT活性,评价Tat生物学功能.PCR扩增H HV-8复制和转录激活蛋白Rta启动子区上游序列,并克隆至pGL-3 载体中,构建Rta启动子+虫荧光素酶(Luciferase)报告基因重组质粒.此重组质粒进一步电转染预先感染了LZRS-Tat101病毒的BC-3细胞,TPA刺激后收集细胞,检测Luciferase活性 .结果显示:①重组反转录病毒感染BCBL-1细胞,一次感染效率达56 %;②重组LZRS-Tat101病毒能够在其感染的BCBL-1细胞中表达Tat蛋白,且表达蛋白具有转录激活功能;③Tat蛋白不能有效上调 HHV-8 Rta启动子活性;④细胞内HIV-1 Tat蛋白诱导HH V-8可溶性周期复制的能力较弱.提示,单纯HIV-1 Tat蛋白并不能激活潜伏感染的HHV-8.

  2. Polarized expression of the membrane ASP protein derived from HIV-1 antisense transcription in T cells

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    Gay Bernard

    2011-09-01

    Full Text Available Abstract Background Retroviral gene expression generally depends on a full-length transcript that initiates in the 5' LTR, which is either left unspliced or alternatively spliced. We and others have demonstrated the existence of antisense transcription initiating in the 3' LTR in human lymphotropic retroviruses, including HTLV-1, HTLV-2, and HIV-1. Such transcripts have been postulated to encode antisense proteins important for the establishment of viral infections. The antisense strand of the HIV-1 proviral DNA contains an ORF termed asp, coding for a highly hydrophobic protein. However, although anti-ASP antibodies have been described to be present in HIV-1-infected patients, its in vivo expression requires further support. The objective of this present study was to clearly demonstrate that ASP is effectively expressed in infected T cells and to provide a better characterization of its subcellular localization. Results We first investigated the subcellular localization of ASP by transfecting Jurkat T cells with vectors expressing ASP tagged with the Flag epitope to its N-terminus. Using immunofluorescence microscopy, we found that ASP localized to the plasma membrane in transfected Jurkat T cells, but with different staining patterns. In addition to an entire distribution to the plasma membrane, ASP showed an asymmetric localization and could also be detected in membrane connections between two cells. We then infected Jurkat T cells with NL4.3 virus coding for ASP tagged with the Flag epitope at its C-terminal end. By this approach, we were capable of showing that ASP is effectively expressed from the HIV-1 3' LTR in infected T cells, with an asymmetric localization of the viral protein at the plasma membrane. Conclusion These results demonstrate for the first time that ASP can be detected when expressed from full-length HIV-1 proviral DNA and that its localization is consistent with Jurkat T cells overexpressing ASP.

  3. Polarized expression of the membrane ASP protein derived from HIV-1 antisense transcription in T cells.

    Science.gov (United States)

    Clerc, Isabelle; Laverdure, Sylvain; Torresilla, Cynthia; Landry, Sébastien; Borel, Sophie; Vargas, Amandine; Arpin-André, Charlotte; Gay, Bernard; Briant, Laurence; Gross, Antoine; Barbeau, Benoît; Mesnard, Jean-Michel

    2011-09-19

    Retroviral gene expression generally depends on a full-length transcript that initiates in the 5' LTR, which is either left unspliced or alternatively spliced. We and others have demonstrated the existence of antisense transcription initiating in the 3' LTR in human lymphotropic retroviruses, including HTLV-1, HTLV-2, and HIV-1. Such transcripts have been postulated to encode antisense proteins important for the establishment of viral infections. The antisense strand of the HIV-1 proviral DNA contains an ORF termed asp, coding for a highly hydrophobic protein. However, although anti-ASP antibodies have been described to be present in HIV-1-infected patients, its in vivo expression requires further support. The objective of this present study was to clearly demonstrate that ASP is effectively expressed in infected T cells and to provide a better characterization of its subcellular localization. We first investigated the subcellular localization of ASP by transfecting Jurkat T cells with vectors expressing ASP tagged with the Flag epitope to its N-terminus. Using immunofluorescence microscopy, we found that ASP localized to the plasma membrane in transfected Jurkat T cells, but with different staining patterns. In addition to an entire distribution to the plasma membrane, ASP showed an asymmetric localization and could also be detected in membrane connections between two cells. We then infected Jurkat T cells with NL4.3 virus coding for ASP tagged with the Flag epitope at its C-terminal end. By this approach, we were capable of showing that ASP is effectively expressed from the HIV-1 3' LTR in infected T cells, with an asymmetric localization of the viral protein at the plasma membrane. These results demonstrate for the first time that ASP can be detected when expressed from full-length HIV-1 proviral DNA and that its localization is consistent with Jurkat T cells overexpressing ASP.

  4. Regional gene expression of LOX-1, VCAM-1, and ICAM-1 in aorta of HIV-1 transgenic rats

    DEFF Research Database (Denmark)

    Hag, Anne Mette Fisker; Kristoffersen, Ulrik Sloth; Pedersen, Sune Folke

    2009-01-01

    was elevated in the HIV-1Tg rats compared to controls, but the ICAM-1 gene expression profile did not show any differences between the groups. CONCLUSIONS/SIGNIFICANCE: HIV-1Tg rats have gene expression patterns indicating endothelial dysfunction and accelerated atherosclerosis in aorta, suggesting that HIV...

  5. Acquisition of HIV-1 resistance in T lymphocytes using an ACA-specific E. coli mRNA interferase.

    Science.gov (United States)

    Chono, Hideto; Matsumoto, Kazuya; Tsuda, Hiroshi; Saito, Naoki; Lee, Karim; Kim, Sujeong; Shibata, Hiroaki; Ageyama, Naohide; Terao, Keiji; Yasutomi, Yasuhiro; Mineno, Junichi; Kim, Sunyoung; Inouye, Masayori; Kato, Ikunoshin

    2011-01-01

    Transcriptional activation of gene expression directed by the long terminal repeat (LTR) of HIV-1 requires both the transactivation response element (TAR) and Tat protein. HIV-1 mutants lacking a functional tat gene are not able to proliferate. Here we take a genetic approach to suppress HIV-1 replication based on Tat-dependent production of MazF, an ACA-specific endoribonuclease (mRNA interferase) from Escherichia coli. When induced, MazF is known to cause Bak- and NBK-dependent apoptotic cell death in mammalian cells. We first constructed a retroviral vector, in which the mazF (ACA-less) gene was inserted under the control of the HIV-1 LTR, which was then transduced into CD4+ T-lymphoid CEM-SS cells in such a way that, upon HIV-1 infection, the mazF gene is induced to destroy the infecting HIV-1 mRNA, preventing HIV-1 replication. Indeed, when the transduced cells were infected with HIV-1 IIIB, the viral replication was effectively inhibited, as HIV-1 IIIB p24 could not be detected in the culture medium. Consistently, not only cell growth but also the CD4 level was not affected by the infection. These results suggest that the HIV-1-LTR-regulated mazF gene was effectively induced upon HIV-1 IIIB infection, which is sufficient enough to destroy the viral mRNA from the infected HIV-1 IIIB to completely block viral proliferation in the cells, but not to affect normal cell growth. These results indicate that the T cells transduced with the HIV-1-LTR-regulated mazF gene acquire HIV-1 resistance, providing an intriguing potential for the use of the HIV-1-LTR-regulated mazF gene in anti-HIV gene therapy.

  6. The HIV-1 associated protein, Tat1–86, impairs dopamine transporters and interacts with cocaine to reduce nerve terminal function: a no-net-flux microdialysis study

    Science.gov (United States)

    Ferris, Mark J.; Frederick-Duus, Danielle; Fadel, Jim; Mactutus, Charles F.; Booze, Rosemarie M.

    2009-01-01

    Injection drug use accounts for approximately one-third of HIV-infections in the United States. HIV associated proteins have been shown to interact with various drugs of abuse to incite concerted neurotoxicity. One common area for their interaction is the nerve terminal, including dopamine transporter (DAT) systems. However, results regarding DAT function and regulation in HIV-infection, regardless of drug use, are mixed. Thus, the present experiments were designed to explicitly control Tat and cocaine administration in an in vivo model in order to reconcile differences that exist in the literature to date. We examined Tat plus cocaine-induced alterations using no-net-flux microdialysis, which is sensitive to alterations in DAT function, in order to test the potential for DAT as an early mediator of HIV-induced oxidative stress and neurodegeneration in vivo. Within 5 hours of intra-accumbal administration of the HIV-associated protein, Tat, we noted a significant reduction in local DAT efficiency with little change in DA overflow/release dynamics. Further, at 48 hrs post-Tat administration, we demonstrated a concerted effect of the HIV-protein Tat with cocaine on both uptake and release function. Finally, we discuss the extent to which DAT dysfunction may be considered a predecessor to generalized nerve terminal dysfunction. Characterization of DAT dysfunction in vivo may provide an early pharamacotherapeutic target, which in turn may prevent or attenuate downstream mediators of neurotoxicity (i.e., reactive species) to DA systems occurring in NeuroAIDS. PMID:19344635

  7. Overcoming HIV-1 resistance to RNA interference.

    Science.gov (United States)

    Boden, Daniel; Pusch, Oliver; Ramratnam, Bharat

    2007-05-01

    RNAi refers to the sequence-specific degradation of RNA that follows the cellular introduction of homologous short interfering (si) RNA. RNAi has emerged as a powerful tool to probe the function of genes of known sequence in vitro and in vivo. Advances in vector design permit the effective expression of siRNA in human cells. Numerous recent investigations have described the ability of RNAi to decrease the replication of human immunodeficiency virus type 1 (HIV-1) in lymphocytic cells using siRNA targeting viral (e.g. tat, gag, rev) and host (e.g. CCR5, CD4) proteins. Can RNAi be used as a form of genetic therapy for HIV-1 infection? Recent data indicate that the dynamic replication kinetics of HIV-1 pose a considerable barrier to achieving durable virus suppression by RNAi with the rapid emergence of HIV-1 mutants resistant to siRNA. This review summarizes recent work on HIV-1 specific RNAi with a focus on potential strategies to overcome HIV-1 resistance to RNAi.

  8. Construction of Recombinant Fowlpox Virus (rFpv) Expressing HIV-1 Gag-pol Protein

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The induction of human immunodeficiency virus(HIV)-specific T-cell response is generally considered as critical to the development of effective immunity to HIV type 1 ( HIV-1 ). Recombinant Avipoxvirus vectors are used widely for vaccination against HIV-1, where the induction of a cytotoxic CD8 + T-cell(CTL) response seems to be an important component of protective immunity. A recombinant fowlpox virus(rFPV/Gag-pol) expressing the Gag-pol protein of HIV was constructed and characterized. The specific expression protein in CEF cells infected by recombinant fowlpox and the specific antibody in the sera of mice immunized with rFPV were analyzed via Westeru-blot.

  9. Astrocytic expression of HIV-1 Nef impairs spatial and recognition memory

    OpenAIRE

    2012-01-01

    Despite the widespread use of antiretroviral therapy that effectively limits viral replication, memory impairment remains a dilemma for HIV infected people. In the CNS, HIV infection of astrocytes leads to the production of the HIV-1 Nef protein without viral replication. Post mortem studies have found Nef expression in hippocampal astrocytes of people with HIV associated dementia suggesting that astrocytic Nef may contribute to HIV associated cognitive impairment even when viral replication ...

  10. Inhibition of HIV-1 gene expression by Ciclopirox and Deferiprone, drugs that prevent hypusination of eukaryotic initiation factor 5A

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    Saxena Deepti

    2009-10-01

    Full Text Available Abstract Background Eukaryotic translation initiation factor eIF5A has been implicated in HIV-1 replication. This protein contains the apparently unique amino acid hypusine that is formed by the post-translational modification of a lysine residue catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase (DOHH. DOHH activity is inhibited by two clinically used drugs, the topical fungicide ciclopirox and the systemic medicinal iron chelator deferiprone. Deferiprone has been reported to inhibit HIV-1 replication in tissue culture. Results Ciclopirox and deferiprone blocked HIV-1 replication in PBMCs. To examine the underlying mechanisms, we investigated the action of the drugs on eIF5A modification and HIV-1 gene expression in model systems. At early times after drug exposure, both drugs inhibited substrate binding to DOHH and prevented the formation of mature eIF5A. Viral gene expression from HIV-1 molecular clones was suppressed at the RNA level independently of all viral genes. The inhibition was specific for the viral promoter and occurred at the level of HIV-1 transcription initiation. Partial knockdown of eIF5A-1 by siRNA led to inhibition of HIV-1 gene expression that was non-additive with drug action. These data support the importance of eIF5A and hypusine formation in HIV-1 gene expression. Conclusion At clinically relevant concentrations, two widely used drugs blocked HIV-1 replication ex vivo. They specifically inhibited expression from the HIV-1 promoter at the level of transcription initiation. Both drugs interfered with the hydroxylation step in the hypusine modification of eIF5A. These results have profound implications for the potential therapeutic use of these drugs as antiretrovirals and for the development of optimized analogs.

  11. Inhibition of HIV-1 gene expression by Ciclopirox and Deferiprone, drugs that prevent hypusination of eukaryotic initiation factor 5A.

    Science.gov (United States)

    Hoque, Mainul; Hanauske-Abel, Hartmut M; Palumbo, Paul; Saxena, Deepti; D'Alliessi Gandolfi, Darlene; Park, Myung Hee; Pe'ery, Tsafi; Mathews, Michael B

    2009-10-13

    Eukaryotic translation initiation factor eIF5A has been implicated in HIV-1 replication. This protein contains the apparently unique amino acid hypusine that is formed by the post-translational modification of a lysine residue catalyzed by deoxyhypusine synthase and deoxyhypusine hydroxylase (DOHH). DOHH activity is inhibited by two clinically used drugs, the topical fungicide ciclopirox and the systemic medicinal iron chelator deferiprone. Deferiprone has been reported to inhibit HIV-1 replication in tissue culture. Ciclopirox and deferiprone blocked HIV-1 replication in PBMCs. To examine the underlying mechanisms, we investigated the action of the drugs on eIF5A modification and HIV-1 gene expression in model systems. At early times after drug exposure, both drugs inhibited substrate binding to DOHH and prevented the formation of mature eIF5A. Viral gene expression from HIV-1 molecular clones was suppressed at the RNA level independently of all viral genes. The inhibition was specific for the viral promoter and occurred at the level of HIV-1 transcription initiation. Partial knockdown of eIF5A-1 by siRNA led to inhibition of HIV-1 gene expression that was non-additive with drug action. These data support the importance of eIF5A and hypusine formation in HIV-1 gene expression. At clinically relevant concentrations, two widely used drugs blocked HIV-1 replication ex vivo. They specifically inhibited expression from the HIV-1 promoter at the level of transcription initiation. Both drugs interfered with the hydroxylation step in the hypusine modification of eIF5A. These results have profound implications for the potential therapeutic use of these drugs as antiretrovirals and for the development of optimized analogs.

  12. Ectopic expression of anti-HIV-1 shRNAs protects CD8{sup +} T cells modified with CD4ζ CAR from HIV-1 infection and alleviates impairment of cell proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Kamata, Masakazu, E-mail: masa3k@ucla.edu [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Kim, Patrick Y. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ng, Hwee L. [Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Ringpis, Gene-Errol E.; Kranz, Emiko; Chan, Joshua; O' Connor, Sean [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Yang, Otto O. [Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Division of Infectious Diseases, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States); AIDS Healthcare Foundation, Los Angeles, CA (United States); Chen, Irvin S.Y. [Division of Hematology-Oncology, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine at UCLA, Los Angeles, CA (United States); UCLA AIDS Institute, Los Angeles, CA (United States)

    2015-07-31

    Chimeric antigen receptors (CARs) are artificially engineered receptors that confer a desired specificity to immune effector T cells. As an HIV-1-specific CAR, CD4ζ CAR has been extensively tested in vitro as well as in clinical trials. T cells modified with this CAR mediated highly potent anti-HIV-1 activities in vitro and were well-tolerated in vivo, but exerted limited effects on viral load and reservoir size due to poor survival and/or functionality of the transduced cells in patients. We hypothesize that ectopic expression of CD4ζ on CD8{sup +} T cells renders them susceptible to HIV-1 infection, resulting in poor survival of those cells. To test this possibility, highly purified CD8{sup +} T cells were genetically modified with a CD4ζ-encoding lentiviral vector and infected with HIV-1. CD8{sup +} T cells were vulnerable to HIV-1 infection upon expression of CD4ζ as evidenced by elevated levels of p24{sup Gag} in cells and culture supernatants. Concurrently, the number of CD4ζ-modified CD8{sup +} T cells was reduced relative to control cells upon HIV-1 infection. To protect these cells from HIV-1 infection, we co-expressed two anti-HIV-1 shRNAs previously developed by our group together with CD4ζ. This combination vector was able to suppress HIV-1 infection without impairing HIV-1-dependent effector activities of CD4ζ. In addition, the number of CD4ζ-modified CD8{sup +} T cells maintained similar levels to that of the control even under HIV-1 infection. These results suggest that protecting CD4ζ-modified CD8{sup +} T cells from HIV-1 infection is required for prolonged HIV-1-specific immune surveillance. - Highlights: • Ectopic expression of CD4ζ CAR in CD8{sup +} T cells renders them susceptible to HIV-1 infection. • Co-expression of two anti-HIV-1 shRNAs protects CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection. • Protecting CD4ζ CAR-modified CD8{sup +} T cells from HIV-1 infection suppresses its cytopathic effect.

  13. Expression of HIV-1 antigens in plants as potential subunit vaccines

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    Tanzer Fiona L

    2008-06-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 has infected more than 40 million people worldwide, mainly in sub-Saharan Africa. The high prevalence of HIV-1 subtype C in southern Africa necessitates the development of cheap, effective vaccines. One means of production is the use of plants, for which a number of different techniques have been successfully developed. HIV-1 Pr55Gag is a promising HIV-1 vaccine candidate: we compared the expression of this and a truncated Gag (p17/p24 and the p24 capsid subunit in Nicotiana spp. using transgenic plants and transient expression via Agrobacterium tumefaciens and recombinant tobamovirus vectors. We also investigated the influence of subcellular localisation of recombinant protein to the chloroplast and the endoplasmic reticulum (ER on protein yield. We partially purified a selected vaccine candidate and tested its stimulation of a humoral and cellular immune response in mice. Results Both transient and transgenic expression of the HIV antigens were successful, although expression of Pr55Gag was low in all systems; however, the Agrobacterium-mediated transient expression of p24 and p17/p24 yielded best, to more than 1 mg p24/kg fresh weight. Chloroplast targeted protein levels were highest in transient and transgenic expression of p24 and p17/p24. The transiently-expressed p17/p24 was not immunogenic in mice as a homologous vaccine, but it significantly boosted a humoral and T cell immune response primed by a gag DNA vaccine, pTHGagC. Conclusion Transient agroinfiltration was best for expression of all of the recombinant proteins tested, and p24 and p17/p24 were expressed at much higher levels than Pr55Gag. Our results highlight the usefulness of plastid signal peptides in enhancing the production of recombinant proteins meant for use as vaccines. The p17/p24 protein effectively boosted T cell and humoral responses in mice primed by the DNA vaccine pTHGagC, showing that this plant

  14. Interferon-α Subtypes in an Ex Vivo Model of Acute HIV-1 Infection: Expression, Potency and Effector Mechanisms.

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    Michael S Harper

    Full Text Available HIV-1 is transmitted primarily across mucosal surfaces and rapidly spreads within the intestinal mucosa during acute infection. The type I interferons (IFNs likely serve as a first line of defense, but the relative expression and antiviral properties of the 12 IFNα subtypes against HIV-1 infection of mucosal tissues remain unknown. Here, we evaluated the expression of all IFNα subtypes in HIV-1-exposed plasmacytoid dendritic cells by next-generation sequencing. We then determined the relative antiviral potency of each IFNα subtype ex vivo using the human intestinal Lamina Propria Aggregate Culture model. IFNα subtype transcripts from the centromeric half of the IFNA gene complex were highly expressed in pDCs following HIV-1 exposure. There was an inverse relationship between IFNA subtype expression and potency. IFNα8, IFNα6 and IFNα14 were the most potent in restricting HIV-1 infection. IFNα2, the clinically-approved subtype, and IFNα1 were both highly expressed but exhibited relatively weak antiviral activity. The relative potencies correlated with binding affinity to the type I IFN receptor and the induction levels of HIV-1 restriction factors Mx2 and Tetherin/BST-2 but not APOBEC3G, F and D. However, despite the lack of APOBEC3 transcriptional induction, the higher relative potency of IFNα8 and IFNα14 correlated with stronger inhibition of virion infectivity, which is linked to deaminase-independent APOBEC3 restriction activity. By contrast, both potent (IFNα8 and weak (IFNα1 subtypes significantly induced HIV-1 GG-to-AG hypermutation. The results unravel non-redundant functions of the IFNα subtypes against HIV-1 infection, with strong implications for HIV-1 mucosal immunity, viral evolution and IFNα-based functional cure strategies.

  15. Interactions between human immunodeficiency virus (HIV-1 Vpr expression and innate immunity influence neurovirulence

    Directory of Open Access Journals (Sweden)

    Ballanyi Klaus

    2011-06-01

    Full Text Available Abstract Background Viral diversity and abundance are defining properties of human immunodeficiency virus (HIV-1's biology and pathogenicity. Despite the increasing availability of antiretroviral therapy, HIV-associated dementia (HAD continues to be a devastating consequence of HIV-1 infection of the brain although the underlying disease mechanisms remain uncertain. Herein, molecular diversity within the HIV-1 non-structural gene, Vpr, was examined in RNA sequences derived from brain and blood of HIV/AIDS patients with or without HIV-associated dementia (HAD together with the ensuing pathobiological effects. Results Cloned brain- and blood-derived full length vpr alleles revealed that amino acid residue 77 within the brain-derived alleles distinguished HAD (77Q from non-demented (ND HIV/AIDS patients (77R (p vpr transcripts were more frequently detected in HAD brains (p IFN-α, MX1 and BST-2 transcript levels in human glia relative to the 77Q-HAD encoding virus (p Vpr77Q-HAD, 77R (pVpr77R-ND or Vpr null (pVpr(--containing vectors showed that the pVpr77R-ND vector induced higher levels of immune gene expression (p p IFN-α, MX1, PRKRA and BST-2 relative to 77Q-HAD peptide (p p p Conclusions These observations underscored the potent neuropathogenic properties of Vpr but also indicated viral diversity modulates innate neuroimmunity and neurodegeneration.

  16. Immunogenicity of DNA and Recombinant Sendai Virus Vaccines Expressing the HIV-1 gag Gene

    Institute of Scientific and Technical Information of China (English)

    Xia FENG; Shuang-qing YU; Tsugumine Shu; Tetsuro Matano; Mamoru Hasegawa; Xiao-li WANG; Hong-tao MA; Hong-xia LI; Yi ZENG

    2008-01-01

    Combinations of DNA and recombinant-viral-vector based vaccines are promising AIDS vaccine methods because of their potential for inducing cellular immune responses. It was found that Gag-specific cytotoxic lymphocyte (CTL) responses were associated with lowering viremia in an untreated HIV-1 infected cohort. The main objectives of our studies were the construction of DNA and recombinant Sendal virus vector (rSeV) vaccines containing a gag gene from the prevalent Thailand subtype B strain in China and trying to use these vaccines for therapeutic and prophylactic vaccines. The candidate plasmid DNA vaccine pcDNA3.1(+)-gag and recombinant Sendai virus vaccine (rSeV-gag) were constructed separately. It was verified by Western blotting analysis that both DNA and rSeV-gag vaccines expressed the HIV-1 Gag protein correctly and efficiently. Balb/c mice were immunized with these two vaccines in different administration schemes. HIV-1 Gag-specific CTL responses and antibody levels were detected by intracellular cytokine staining assay and enzyme-linked immunosorbant assay (ELISA) respectively. Combined vaccines in a DNA prime/rSeV-gag boost vaccination regimen induced the strongest and most long-lasting Gag-specific CTL and antibody responses. It maintained relatively high levels even 9 weeks post immunization. This data indicated that the prime-boost regimen with DNA and rSeV-gag vaccines may offer promising HIV vaccine regimens.

  17. Binding of HIV-1 virions to α4β7 expressing cells and impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells

    Institute of Scientific and Technical Information of China (English)

    Chang; Li; Wei; Jin; Tao; Du; Biao; Wu; Yalan; Liu; Robin; J; Shattock; Qinxue; Hu

    2014-01-01

    HIV-1 envelope glycoprotein is reported to interact with α4β7, an integrin mediating the homing of lymphocytes to gut-associated lymphoid tissue, but the significance of α4β7 in HIV-1 infection remains controversial. Here, using HIV-1 strain Ba L, the gp120 of which was previously shown to be capable of interacting with α4β7, we demonstrated that α4β7 can mediate the binding of whole HIV-1 virions to α4β7-expressing transfectants. We further constructed a cell line stably expressing α4β7 and confirmed the α4β7-mediated HIV-1 binding. In primary lymphocytes with activated α4β7 expression, we also observed significant virus binding which can be inhibited by an anti-α4β7 antibody. Moreover, we investigated the impact of antagonizing α4β7 on HIV-1 infection of primary CD4+ T cells. In α4β7-activated CD4+ T cells, both anti-α4β7 antibodies and introduction of shorthairpin RNAs specifically targeting α4β7 resulted in a decreased HIV-1 infection. Our findings indicate that α4β7 may serve as an attachment factor at least for some HIV-1 strains. The established approach provides a promising means for the investigation of other viral strains to understand the potential roles of α4β7 in HIV-1 infection.

  18. Binding affinity and inhibitory potency of neomycin and streptomycin on the Tat peptide interaction with HIV-1 TAR RNA detected by on-line acoustic wave sensor.

    Science.gov (United States)

    Tassew, Nardos; Thompson, Michael

    2003-10-07

    The binding of two aminoglycoside antibiotics, neomycin and streptomycin, to a segment of the transactivation responsive region (TAR) RNA of the human immunodeficiency virus, and their inhibitory potency to disrupt the interaction of the RNA with a regulatory Tat protein-derived peptide, have been studied using a flow-through acoustic wave detector system. Binding affinity is directly correlated with the inhibitory potency of these molecules and the acoustic wave detection system shows that neomycin exhibits at least a ten-fold greater affinity for TAR RNA and that it is also a more potent inhibitor than streptomycin. These results are in agreement with previous studies. However, unlike the time-consuming batch-based assays, use of the flow-through format offers considerable potential for the rapid screening of the chemistry of relatively small-molecule-nucleic acid binding events.

  19. Effects of root, shoot, leaf and seed extracts of seven Artemisia species on HIV-1 replication and CD4 expression

    Directory of Open Access Journals (Sweden)

    Hassan Mohabatkar

    2015-12-01

    Full Text Available Objective: To investigate the effects of flower, leaf, shoot and root extracts of seven Artemisia species on peripheral blood mononuclear cells (PBMCs toxicity and HIV-1 replication. Methods: The studied Artemisia species were Artemisia absinthium, Artemisia khorasanica, Artemisia deserti, Artemisia fragrans, Artemisia aucheri, Artemisia sieberi and Artemisia vulgaris. The activity of these plant extracts on HIV-1 replication and CD4 expression was performed by HIV-1 p24 antigen kit and flow cytometry respectively. Results: The results demonstrated that flower extracts of all species increased PBMCs number more than shoot, leaf and root extracts. However, the frequency of CD4 expression in PBMC was not increased in the presence of all flower extracts. The flower extracts of all species had inhibitory effect on HIV-1 replication. Conclusions: In conclusion, the results demonstrated that flower extracts of Artemisia species are good candidates for further studies as anticancer agents.

  20. HIV-1 TAR miRNA protects against apoptosis by altering cellular gene expression

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    Meiri Eti

    2009-02-01

    Full Text Available Abstract Background RNA interference is a gene regulatory mechanism that employs small RNA molecules such as microRNA. Previous work has shown that HIV-1 produces TAR viral microRNA. Here we describe the effects of the HIV-1 TAR derived microRNA on cellular gene expression. Results Using a variation of standard techniques we have cloned and sequenced both the 5' and 3' arms of the TAR miRNA. We show that expression of the TAR microRNA protects infected cells from apoptosis and acts by down-regulating cellular genes involved in apoptosis. Specifically, the microRNA down-regulates ERCC1 and IER3, protecting the cell from apoptosis. Comparison to our cloned sequence reveals possible target sites for the TAR miRNA as well. Conclusion The TAR microRNA is expressed in all stages of the viral life cycle, can be detected in latently infected cells, and represents a mechanism wherein the virus extends the life of the infected cell for the purpose of increasing viral replication.

  1. Functional diversity of HIV-1 envelope proteins expressed by contemporaneous plasma viruses

    Directory of Open Access Journals (Sweden)

    Clavel François

    2008-02-01

    Full Text Available Abstract Background Numerous studies have shown that viral quasi-species with genetically diverse envelope proteins (Env replicate simultaneously in patients infected with the human immunodeficiency virus type 1 (HIV-1. Less information is available concerning the extent that envelope sequence diversity translates into a diversity of phenotypic properties, including infectivity and resistance to entry inhibitors. Methods To study these questions, we isolated genetically distinct contemporaneous clonal viral populations from the plasma of 5 HIV-1 infected individuals (n = 70, and evaluated the infectivity of recombinant viruses expressing Env proteins from the clonal viruses in several target cells. The sensitivity to entry inhibitors (enfuvirtide, TAK-799, soluble CD4 and monoclonal antibodies (2G12, 48d, 2F5 was also evaluated for a subset of the recombinant viruses (n = 20. Results Even when comparisons were restricted to viruses with similar tropism, the infectivity for a given target cell of viruses carrying different Env proteins from the same patient varied over an approximately 10-fold range, and differences in their relative ability to infect different target cells were also observed. Variable region haplotypes associated with high and low infectivity could be identified for one patient. In addition, clones carrying unique mutations in V3 often displayed low infectivity. No correlation was observed between viral infectivity and sensitivity to inhibition by any of the six entry inhibitors evaluated, indicating that these properties can be dissociated. Significant inter-patient differences, independent of infectivity, were observed for the sensitivity of Env proteins to several entry inhibitors and their ability to infect different target cells. Conclusion These findings demonstrate the marked functional heterogeneity of HIV-1 Env proteins expressed by contemporaneous circulating viruses, and underscore the advantage of clonal analyses in

  2. Identification of Host Micro RNAs That Differentiate HIV-1 and HIV-2 Infection Using Genome Expression Profiling Techniques

    Directory of Open Access Journals (Sweden)

    Krishnakumar Devadas

    2016-05-01

    Full Text Available While human immunodeficiency virus type 1 and 2 (HIV-1 and HIV-2 share many similar traits, major differences in pathogenesis and clinical outcomes exist between the two viruses. The differential expression of host factors like microRNAs (miRNAs in response to HIV-1 and HIV-2 infections are thought to influence the clinical outcomes presented by the two viruses. MicroRNAs are small non-coding RNA molecules which function in transcriptional and post-transcriptional regulation of gene expression. MiRNAs play a critical role in many key biological processes and could serve as putative biomarker(s for infection. Identification of miRNAs that modulate viral life cycle, disease progression, and cellular responses to infection with HIV-1 and HIV-2 could reveal important insights into viral pathogenesis and provide new tools that could serve as prognostic markers and targets for therapeutic intervention. The aim of this study was to elucidate the differential expression profiles of host miRNAs in cells infected with HIV-1 and HIV-2 in order to identify potential differences in virus-host interactions between HIV-1 and HIV-2. Differential expression of host miRNA expression profiles was analyzed using the miRNA profiling polymerase chain reaction (PCR arrays. Differentially expressed miRNAs were identified and their putative functional targets identified. The results indicate that hsa-miR 541-3p, hsa-miR 518f-3p, and hsa-miR 195-3p were consistently up-regulated only in HIV-1 infected cells. The expression of hsa-miR 1225-5p, hsa-miR 18a* and hsa-miR 335 were down modulated in HIV-1 and HIV-2 infected cells. Putative functional targets of these miRNAs include genes involved in signal transduction, metabolism, development and cell death.

  3. Inhibition of HIV-1 Integrase gene expression by 10-23 DNAzyme

    Indian Academy of Sciences (India)

    Nirpendra Singh; Atul Ranjan; Souvik Sur; Ramesh Chandra; Vibha Tandon

    2012-07-01

    HIV Integrase (IN) is an enzyme that is responsible for the integration of the proviral genome into the human genome, and this integration step is the first step of the virus hijacking the human cell machinery for its propagation and replication. 10-23 DNAzyme has the potential to suppress gene expressions through sequence-specific mRNA cleavage. We have designed three novel DNAzymes, DIN54, DIN116, and DIN152, against HIV-1 Integrase gene using Mfold software and evaluated them for target site cleavage activity on the in vitro transcribed mRNA. All DNAzymes were tested for its inhibition of expression of HIV Integrase protein in the transiently transfected cell lines. DIN116 and DIN152 inhibited IN-EGFP expression by 80% and 70% respectively.

  4. Nicotine mediates expression of genes related to antioxidant capacity and oxidative stress response in HIV-1 transgenic rat brain.

    Science.gov (United States)

    Song, Guohua; Nesil, Tanseli; Cao, Junran; Yang, Zhongli; Chang, Sulie L; Li, Ming D

    2016-02-01

    Oxidative stress plays an important role in the progression of HIV-1 infection. Nicotine can either protect neurons from neurodegeneration or induce oxidative stress, depending on its dose and degree of oxidative stress impairment. However, the relationship between nicotine and oxidative stress in the HIV-1-infected individuals remains largely unknown. The purpose of this study was to determine the effect of nicotine on expression of genes related to the glutathione (GSH)-centered antioxidant system and oxidative stress in the nucleus accumbens (NAc) and ventral tegmental area (VTA) of HIV-1 transgenic (HIV-1Tg) and F344 control rats. Adult HIV-1Tg and F344 rats received nicotine (0.4 mg/kg, base, s.c.) or saline injections once per day for 27 days. At the end of treatment, various brain regions including the NAc and VTA were collected from each rat. Following total RNA extraction and complementary DNA (cDNA) synthesis of each sample, quantitative reverse transcription PCR (RT-PCR) analysis was performed for 43 oxidative-stress-related genes. Compared with F344 control rats, HIV-1Tg rats showed a significant downregulation of genes involved in ATPase and cyctochrome oxidase at the messenger RNA (mRNA) level in both regions. Further, we found a significant downregulation of Gstm5 in the NAc and upregulation of Cox1, Cox3, and Gsta6 in the VTA of HIV-1Tg rats. HIV-1Tg rats showed brain-region-specific responses to chronic nicotine treatment. This response resulted in a change in the expression of genes involved in antioxidant mechanisms including the downregulation of genes such as Atp5h, Calml1, Gpx7, Gstm5, Gsr, and Gsta6 and upregulation of Sod1 in the NAc, as well as downregulation of genes like Cox5a, Gpx4, Gpx6, Gpx7, Gstm5, and Sod1 in the VTA of HIV-1Tg rats. Together, we conclude that chronic nicotine treatment has a dual effect on the antioxidant defense system and oxidative-stress-induced apoptosis signaling in HIV-1Tg rats. These findings suggest that

  5. Astrocytic expression of HIV-1 Nef impairs spatial and recognition memory.

    Science.gov (United States)

    Chompre, Gladys; Cruz, Emmanuel; Maldonado, Lucianette; Rivera-Amill, Vanessa; Porter, James T; Noel, Richard J

    2013-01-01

    Despite the widespread use of antiretroviral therapy that effectively limits viral replication, memory impairment remains a dilemma for HIV infected people. In the CNS, HIV infection of astrocytes leads to the production of the HIV-1 Nef protein without viral replication. Post mortem studies have found Nef expression in hippocampal astrocytes of people with HIV associated dementia suggesting that astrocytic Nef may contribute to HIV associated cognitive impairment even when viral replication is suppressed. To test whether astrocytic expression of Nef is sufficient to induce cognitive deficits, we examined the effect of implanting primary rat astrocytes expressing Nef into the hippocampus on spatial and recognition memory. Rats implanted unilaterally with astrocytes expressing Nef showed impaired novel location and novel object recognition in comparison with controls implanted with astrocytes expressing green fluorescent protein (GFP). This impairment was correlated with an increase in chemokine ligand 2 (CCL2) expression and the infiltration of peripheral macrophages into the hippocampus at the site of injection. Furthermore, the Nef exposed rats exhibited a bilateral loss of CA3 neurons. These results suggest that Nef protein expressed by the implanted astrocytes activates the immune system leading to neuronal damage and spatial and recognition memory deficits. Therefore, the continued expression of Nef by astrocytes in the absence of viral replication has the potential to contribute to HIV associated cognitive impairment.

  6. HIV Tat Impairs Neurogenesis through Functioning As a Notch Ligand and Activation of Notch Signaling Pathway.

    Science.gov (United States)

    Fan, Yan; Gao, Xiang; Chen, Jinhui; Liu, Ying; He, Johnny J

    2016-11-02

    Alterations in adult neurogenesis have been noted in the brain of HIV-infected individuals and are likely linked to HIV-associated neurocognitive deficits, including those in learning and memory. But the underlying molecular mechanisms are not fully understood. In the study, we took advantage of doxycycline-inducible and astrocyte-specific HIV-1 Tat transgenic mice (iTat) and determined the relationship between Tat expression and neurogenesis. Tat expression in astrocytes was associated with fewer neuron progenitor cells (NPCs), fewer immature neurons, and fewer mature neurons in the dentate gyrus of the hippocampus of the mouse brain. In vitro NPC-derived neurosphere assays showed that Tat-containing conditioned media from astrocytes or recombinant Tat protein inhibited NPC proliferation and migration and altered NPC differentiation, while immunodepletion of Tat from Tat-containing conditioned media or heat inactivation of recombinant Tat abrogated those effects. Notch signaling downstream gene Hes1 promoter-driven luciferase reporter gene assay and Western blotting showed that recombinant Tat or Tat-containing conditioned media activated Hes1 transcription and protein expression, which were abrogated by Tat heat inactivation, immunodepletion, and cysteine mutation at position 30. Last, Notch signaling inhibitor N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butyl ester (DAPT) significantly rescued Tat-impaired NPC differentiation in vitro and neurogenesis in vivo Together, these results show that Tat adversely affects NPCs and neurogenesis through Notch signaling and point to the potential of developing Notch signaling inhibitors as HIV/neuroAIDS therapeutics.

  7. Expression of HIV-1 broadly neutralizing antibodies mediated by recombinant adeno-associated virus 8 in vitro and in vivo.

    Science.gov (United States)

    Yu, Yongjiao; Fu, Lu; Jiang, Xiaoyu; Guan, Shanshan; Kuai, Ziyu; Kong, Wei; Shi, Yuhua; Shan, Yaming

    2016-12-01

    Despite unremitting efforts since the discovery of human immunodeficiency virus type 1 (HIV-1), an effective vaccine has not been generated. Viral vector-mediated transfer for expression of HIV-1 broadly neutralizing antibodies (BnAbs) is an attractive strategy. In this study, a recombinant adeno-associated virus 8 (rAAV8) vector was used to encode full-length antibodies against HIV-1 in 293T cells and Balb/c mice after gene transfer. The 10E8 or NIH45-46 BnAb was expressed from a single open reading frame by linking the heavy and light chains with a furin cleavage and a 2A self-processing peptide (F2A). The results showed that the BnAbs could be expressed in the 293T cell culture medium. A single intramuscular injection of rAAV8 led to long-term expression of BnAbs in Balb/c mice. The expressed antibodies in the supernatant of 293T cells and in Balb/c mice showed neutralization effects against HIV-1 pseudoviruses. Combined immunization of rAAV8 expressing 10E8 and rAAV8 expressing NIH45-46 in Balb/c mice could increase these neutralization effects on strains of HIV-1 sensitive to 10E8 or NIH45-46 antibody compared with a single injection of rAAV8 expressing either antibody alone. Therefore, the combined immunization may be a potential vaccine approach against HIV-1.

  8. Regional gene expression of LOX-1, VCAM-1, and ICAM-1 in aorta of HIV-1 transgenic rats.

    Directory of Open Access Journals (Sweden)

    Anne Mette Fisker Hag

    Full Text Available BACKGROUND: Increased prevalence of atherosclerotic cardiovascular disease in HIV-infected patients has been observed. The cause of this accelerated atherosclerosis is a matter of controversy. As clinical studies are complicated by a multiplicity of risk-factors and a low incidence of hard endpoints, studies in animal models could be attractive alternatives. METHODOLOGY/PRINCIPAL FINDINGS: We evaluated gene expression of lectin-like oxidized-low-density-lipoprotein receptor-1 (LOX-1, vascular cell adhesion molecule-1 (VCAM-1, and intercellular adhesion molecule-1 (ICAM-1 in HIV-1 transgenic (HIV-1Tg rats; these genes are all thought to play important roles in early atherogenesis. Furthermore, the plasma level of sICAM-1 was measured. We found that gene expressions of LOX-1 and VCAM-1 were higher in the aortic arch of HIV-1Tg rats compared to controls. Also, the level of sICAM-1 was elevated in the HIV-1Tg rats compared to controls, but the ICAM-1 gene expression profile did not show any differences between the groups. CONCLUSIONS/SIGNIFICANCE: HIV-1Tg rats have gene expression patterns indicating endothelial dysfunction and accelerated atherosclerosis in aorta, suggesting that HIV-infection per se may cause atherosclerosis. This transgenic rat model may be a very promising model for further studies of the pathophysiology behind HIV-associated cardiovascular disease.

  9. Hyperthermia stimulates HIV-1 replication.

    Directory of Open Access Journals (Sweden)

    Ferdinand Roesch

    Full Text Available 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.

  10. Hyperthermia stimulates HIV-1 replication.

    Science.gov (United States)

    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.

  11. Quantitative analysis of differentially expressed saliva proteins in human immunodeficiency virus type 1 (HIV-1) infected individuals

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Nawei; Zhang, Zhenyu [Beijing Chaoyang Hospital Affiliated Capital Medical University, Beijing (China); Feng, Shan [MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing (China); Wang, Qingtao [Beijing Chaoyang Hospital Affiliated Capital Medical University, Beijing (China); Malamud, Daniel [NYU College of Dentistry, 345 East 24th Street, New York, NY 10010 (United States); Deng, Haiteng, E-mail: dht@mail.tsinghua.edu.cn [MOE Key Laboratory of Bioinformatics, School of Life Sciences, Tsinghua University, Beijing (China)

    2013-04-24

    Highlights: ► A high-throughput method for profiling and quantification of the differentially expressed proteins in saliva samples was developed. ► Identified that DMBT1, S100A7, S100A8, S100A9 and alpha defensin were up-regulated in saliva from HIV-1 seropositive patients. ► Established analytical strategies are translatable to the clinical setting. -- Abstract: In the present study, we have established a new methodology to analyze saliva proteins from HIV-1-seropositive patients before highly active antiretroviral therapy (HAART) and seronegative controls. A total of 593 and 601 proteins were identified in the pooled saliva samples from 5 HIV-1 subjects and 5 controls, respectively. Forty-one proteins were found to be differentially expressed. Bioinformatic analysis of differentially expressed salivary proteins showed an increase of antimicrobial proteins and decrease of protease inhibitors upon HIV-1 infection. To validate some of these differentially expressed proteins, a high-throughput quantitation method was established to determine concentrations of 10 salivary proteins in 40 individual saliva samples from 20 seropositive patients before HAART and 20 seronegative subjects. This method was based on limited protein separation within the zone of the stacking gel of the 1D SDS PAGE and using isotope-coded synthetic peptides as internal standards. The results demonstrated that a combination of protein profiling and targeted quantitation is an efficient method to identify and validate differentially expressed salivary proteins. Expression levels of members of the calcium-binding S100 protein family and deleted in malignant brain tumors 1 protein (DMBT1) were up-regulated while that of Mucin 5B was down-regulated in HIV-1 seropositive saliva samples, which may provide new perspectives for monitoring HIV-infection and understanding the mechanism of HIV-1 infectivity.

  12. Mycobacterium avium complex augments macrophage HIV-1 production and increases CCR5 expression

    OpenAIRE

    1998-01-01

    Infection with HIV-1 results in pronounced immune suppression and susceptibility to opportunistic infections (OI). Reciprocally, OI augment HIV-1 replication. As we have shown for Mycobacterium avium complex (MAC) and Pneumocystis carinii, macrophages infected with opportunistic pathogens and within lymphoid tissues containing OI, exhibit striking levels of viral replication. To explore potential underlying mechanisms for increased HIV-1 replication associated with coinfection, blood monocyte...

  13. Antigen Gene Cloning and Expression of HIV-1 Toward AIDS Vaccine Design Ⅱ. Subtype Classification and Quasi-species Identification of HIV-1

    Institute of Scientific and Technical Information of China (English)

    ZENG Qingping (曾庆平); YANG Ruiyi (杨瑞仪); FENG Liling (冯丽玲); CHEN Zhuhua (陈竹华); ZENG Changhong (曾常红)

    2002-01-01

    Objectives: To analyze subtypes and quasi-species of isolatedviruses from HIV-1 infected individuals among the populationof Guangdong Province, for understanding the molecularepidemioiogical dynamics of local HIV-1 isolates, thus laying afoundation for designing a candidate AIDS vaccine.Methods: By hetero-duplex mobility assay (HMA) andsingle strand conformation poly- morphism (SSCP) analysison amplicons from single-primed polymerase chain reaction(SP-PCR), subtypes and quasi-species of tested HIV-1 isolateswere elucidated, and amplicons were sequenced forconfirmation.Results: Specific amplicons from different subtypes andquasi-species of HIV-1 could be discernible by HMA andSSCP analysis.Conclusion: HIV-1 isolates from different patients might beeither a different subtype or an identical subtype, and HIV-1isolates from an individual were present in a population ofquasi-species.

  14. Mycobacterium tuberculosis-induced CXCR4 and chemokine expression leads to preferential X4 HIV-1 replication in human macrophages.

    Science.gov (United States)

    Hoshino, Yoshihiko; Tse, Doris B; Rochford, Gemma; Prabhakar, Savita; Hoshino, Satomi; Chitkara, Nishay; Kuwabara, Kenichi; Ching, Elbert; Raju, Bindu; Gold, Jeffrey A; Borkowsky, William; Rom, William N; Pine, Richard; Weiden, Michael

    2004-05-15

    Opportunistic infections such as pulmonary tuberculosis (TB) increase local HIV-1 replication and mutation. As AIDS progresses, alteration of the HIV-1 gp120 V3 sequence is associated with a shift in viral coreceptor use from CCR5 (CD195) to CXCR4 (CD184). To better understand the effect of HIV/TB coinfection, we screened transcripts from bronchoalveolar lavage cells with high density cDNA arrays and found that CXCR4 mRNA is increased in patients with TB. Surprisingly, CXCR4 was predominately expressed on alveolar macrophages (AM). Mycobacterium tuberculosis infection of macrophages in vitro increased CXCR4 surface expression, whereas amelioration of disease reduced CXCR4 expression in vivo. Bronchoalveolar lavage fluid from TB patients had elevated levels of CCL4 (macrophage inflammatory protein-1beta), CCL5 (RANTES), and CX3CL1 (fractalkine), but not CXCL12 (stromal-derived factor-1alpha). We found that M. tuberculosis infection of macrophages in vitro increased viral entry and RT of CXCR4-using [corrected] HIV-1, but not of CCR5-using [corrected] HIV-1. Lastly, HIV-1 derived from the lung contains CD14, suggesting that they were produced in AM. Our results demonstrate that TB produces a permissive environment for replication of CXCR4-using virus by increasing CXCR4 expression in AM and for suppression of CCR5-using HIV-1 by increasing CC chemokine expression. These changes explain in part why TB accelerates the course of AIDS. CXCR4 inhibitors are a rational therapeutic approach in HIV/TB coinfection.

  15. HIV-1 transcription and latency: an update

    Science.gov (United States)

    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

  16. Expression, purification and crystallization of CTB-MPR, a candidate mucosal vaccine component against HIV-1

    Directory of Open Access Journals (Sweden)

    Ho-Hsien Lee

    2014-09-01

    Full Text Available CTB-MPR is a fusion protein between the B subunit of cholera toxin (CTB and the membrane-proximal region of gp41 (MPR, the transmembrane envelope protein of Human immunodeficiency virus 1 (HIV-1, and has previously been shown to induce the production of anti-HIV-1 antibodies with antiviral functions. To further improve the design of this candidate vaccine, X-ray crystallography experiments were performed to obtain structural information about this fusion protein. Several variants of CTB-MPR were designed, constructed and recombinantly expressed in Escherichia coli. The first variant contained a flexible GPGP linker between CTB and MPR, and yielded crystals that diffracted to a resolution of 2.3 Å, but only the CTB region was detected in the electron-density map. A second variant, in which the CTB was directly attached to MPR, was shown to destabilize pentamer formation. A third construct containing a polyalanine linker between CTB and MPR proved to stabilize the pentameric form of the protein during purification. The purification procedure was shown to produce a homogeneously pure and monodisperse sample for crystallization. Initial crystallization experiments led to pseudo-crystals which were ordered in only two dimensions and were disordered in the third dimension. Nanocrystals obtained using the same precipitant showed promising X-ray diffraction to 5 Å resolution in femtosecond nanocrystallography experiments at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The results demonstrate the utility of femtosecond X-ray crystallography to enable structural analysis based on nano/microcrystals of a protein for which no macroscopic crystals ordered in three dimensions have been observed before.

  17. Improved innate and adaptive immunostimulation by genetically modified HIV-1 protein expressing NYVAC vectors.

    Directory of Open Access Journals (Sweden)

    Esther D Quakkelaar

    Full Text Available Attenuated poxviruses are safe and capable of expressing foreign antigens. Poxviruses are applied in veterinary vaccination and explored as candidate vaccines for humans. However, poxviruses express multiple genes encoding proteins that interfere with components of the innate and adaptive immune response. This manuscript describes two strategies aimed to improve the immunogenicity of the highly attenuated, host-range restricted poxvirus NYVAC: deletion of the viral gene encoding type-I interferon-binding protein and development of attenuated replication-competent NYVAC. We evaluated these newly generated NYVAC mutants, encoding HIV-1 env, gag, pol and nef, for their ability to stimulate HIV-specific CD8 T-cell responses in vitro from blood mononuclear cells of HIV-infected subjects. The new vectors were evaluated and compared to the parental NYVAC vector in dendritic cells (DCs, RNA expression arrays, HIV gag expression and cross-presentation assays in vitro. Deletion of type-I interferon-binding protein enhanced expression of interferon and interferon-induced genes in DCs, and increased maturation of infected DCs. Restoration of replication competence induced activation of pathways involving antigen processing and presentation. Also, replication-competent NYVAC showed increased Gag expression in infected cells, permitting enhanced cross-presentation to HIV-specific CD8 T cells and proliferation of HIV-specific memory CD8 T-cells in vitro. The recombinant NYVAC combining both modifications induced interferon-induced genes and genes involved in antigen processing and presentation, as well as increased Gag expression. This combined replication-competent NYVAC is a promising candidate for the next generation of HIV vaccines.

  18. Impaired plant growth and development caused by human immunodeficiency virus type 1 Tat.

    Science.gov (United States)

    Cueno, Marni E; Hibi, Yurina; Imai, Kenichi; Laurena, Antonio C; Okamoto, Takashi

    2010-10-01

    Previous attempts to express the human immunodeficiency virus 1 (HIV-1) Tat (trans-activator of transcription) protein in plants resulted in a number of physiological abnormalities, such as stunted growth and absence of seed formation, that could not be explained. In the study reported here, we expressed Tat in tomato and observed phenotypic abnormalities, including stunted growth, absence of root formation, chlorosis, and plant death, as a result of reduced cytokinin levels. These reduced levels were ascribed to a differentially expressed CKO35 in Tat-bombarded tomato. Of the two CKO isoforms that are naturally expressed in tomato, CKO43 and CKO37, only the expression of CKO37 was affected by Tat. Our analysis of the Tat confirmed that the Arg-rich and RGD motifs of Tat have functional relevance in tomato and that independent mutations at these motifs caused inhibition of the differentially expressed CKO isoform and the extracellular secretion of the Tat protein, respectively, in our Tat-bombarded tomato samples.

  19. BCL11B is a general transcriptional repressor of the HIV-1 long terminal repeat in T lymphocytes through recruitment of the NuRD complex.

    Science.gov (United States)

    Cismasiu, Valeriu B; Paskaleva, Elena; Suman Daya, Sneha; Canki, Mario; Duus, Karen; Avram, Dorina

    2008-10-25

    In this study we provide evidence that the transcription factor BCL11B represses expression from the HIV-1 long terminal repeat (LTR) in T lymphocytes through direct association with the HIV-1 LTR. We also demonstrate that the NuRD corepressor complex mediates BCL11B transcriptional repression of the HIV-1 LTR. In addition, BCL11B and the NuRD complex repressed TAT-mediated transactivation of the HIV-1 LTR in T lymphocytes, pointing to a potential role in initiation of silencing. In support of all the above results, we demonstrate that BCL11B affects HIV-1 replication and virus production, most likely by blocking LTR transcriptional activity. BCL11B showed specific repression for the HIV-1 LTR sequences isolated from seven different HIV-1 subtypes, demonstrating that it is a general transcriptional repressor for all LTRs.

  20. Attenuating HIV Tat/TAR-mediated protein expression by exploring the side chain length of positively charged residues.

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    Wu, Cheng-Hsun; Chen, Yi-Ping; Liu, Shing-Lung; Chien, Fan-Ching; Mou, Chung-Yuan; Cheng, Richard P

    2015-12-07

    RNA is a drug target involved in diverse cellular functions and viral processes. Molecules that inhibit the HIV TAR RNA-Tat protein interaction may attenuate Tat/TAR-dependent protein expression and potentially serve as anti-HIV therapeutics. By incorporating positively charged residues with mixed side chain lengths, we designed peptides that bind TAR RNA with enhanced intracellular activity. Tat-derived peptides that were individually substituted with positively charged residues with varying side chain lengths were evaluated for TAR RNA binding. Positively charged residues with different side chain lengths were incorporated at each Arg and Lys position in the Tat-derived peptide to enhance TAR RNA binding. The resulting peptides showed enhanced TAR RNA binding affinity, cellular uptake, nuclear localization, proteolytic resistance, and inhibition of intracellular Tat/TAR-dependent protein expression compared to the parent Tat-derived peptide with no cytotoxicity. Apparently, the enhanced inhibition of protein expression by these peptides was not determined by RNA binding affinity, but by proteolytic resistance. Despite the high TAR binding affinity, a higher binding specificity would be necessary for practical purposes. Importantly, altering the positively charged residue side chain length should be a viable strategy to generate potentially useful RNA-targeting bioactive molecules.

  1. Tat gets the "green" light on transcription initiation

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    Kashanchi Fatah

    2005-11-01

    Full Text Available Abstract Human immunodeficiency virus type 1 (HIV-1 Tat transactivation is an essential step in the viral life cycle. Over the past several years, it has become widely accepted that Tat exerts its transcriptional effect by binding the transactivation-responsive region (TAR and enhancing transcriptional elongation. Consistent with this hypothesis, it has been shown that Tat promotes the binding of P-TEFb, a transcription elongation factor composed of cyclin T1 and cdk9, and the interaction of Tat with P-TEFb and TAR leads to hyperphosphorylation of the C-terminal domain (CTD of RNA Pol II and increased processivity of RNA Pol II. A recent report, however, has generated renewed interest that Tat may also play a critical role in transcription complex (TC assembly at the preinitiation step. Using in vivo chromatin immunoprecipitation assays, the authors reported that the HIV TC contains TBP but not TBP-associated factors. The stimulatory effect involved the direct interaction of Tat and P-TEFb and was evident at the earliest step of TC assembly, the TBP-TATA box interaction. In this article, we will review this data in context of earlier data which also support Tat's involvement in transcriptional complex assembly. Specifically, we will discuss experiments which demonstrated that Tat interacted with TBP and increased transcription initiation complex stability in cell free assays. We will also discuss studies which demonstrated that over expression of TBP alone was sufficient to obtain Tat activated transcription in vitro and in vivo. Finally, studies using self-cleaving ribozymes which suggested that Tat transactivation was not compatible with pausing of the RNA Pol II at the TAR site will be discussed.

  2. Escherichia coli–expressed near full length HIV-1 envelope glycoprotein is a highly sensitive and specific diagnostic antigen

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    Talha Sheikh M

    2012-11-01

    Full Text Available Abstract Background The Human Immunodeficiency Virus type 1 (HIV-1 envelope glycoprotein gp160, useful in detecting anti-HIV-1 antibodies, is difficult to express in heterologous hosts. The major hurdles are its signal sequence, strong hydrophobic regions and heavy glycosylation. While it has not been possible to express full length recombinant (r-gp160 in E. coli, it can be expressed in insect and mammalian cells, but at relatively higher cost. In this work, we report E. coli-based over-expression of r-gp160 variant and evaluate its performance in diagnostic immunoassays for the detection of anti-HIV-1 antibodies. Methods A deletion variant of r-gp160 lacking hydrophobic regions of the parent full length molecule was expressed in E. coli and purified to near homogeneity using single-step Ni(II-affinity chromatography. Biotinylated and europium(III chelate-labeled versions of this antigen were used to set up one- and two-step time-resolved fluorometric double antigen sandwich assays. The performance of these assays was evaluated against a collection of well-characterized human sera (n=131, that included an in-house panel and four commercially procured panels. Results In-frame deletion of three hydrophobic regions, spanning amino acid residues 1–43, 519–538 and 676–706, of full length HIV-1 gp160 resulted in its expression in E. coli. Both the one- and two-step assays manifested high sensitivity unambiguously identifying 75/77 and 77/77 HIV-1 positive sera, respectively. Both assays also identified all 52 HIV-seronegative sera correctly. Between the two assays, the mean signal-to-cutoff value of the two-step assay was an order of magnitude greater than that of the one-step assay. Both assays were highly specific manifesting no cross-reactivity towards antibodies specific to other viruses like hepatitis B, C, and human T cell leukemia viruses. Conclusions This study has demonstrated the expression of r-gp160 variant in E. coli, by deletion

  3. HIV-1 Nef is transferred from expressing T cells to hepatocytic cells through conduits and enhances HCV replication.

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    In-Woo Park

    Full Text Available 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.

  4. DJ1 Expression Downregulates in Neuroblastoma Cells (SK-N-MC Chronically Exposed to HIV-1 and Cocaine.

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    Upal eRoy

    2015-07-01

    Full Text Available Background: HIV-associated neurological disorder (HAND has long been recognized as a consequence of Human Immunodeficiency Virus (HIV infection in the brain. The pathology of HAND gets more complicated with the recreational drug use such as cocaine. Recent studies have suggested multiple genetic influences involved in the pathology of addiction and HAND but only a fraction of the entire genetic risk has been investigated so far. In this regard, role of DJ1 protein (a gene linked to autosomal recessive early-onset Parkinson’s disease in regulating dopamine transmission and reactive oxygen species (ROS production in neuronal cells will be worth investigating in HIV-1 and cocaine exposed microenvironment. Being a very abundant protein in the brain, DJ1 could serve as a potential marker for early detection of HIV-1 and/or cocaine related neurological disorder.Methods: In vitro analysis was done to observe the effect of HIV-1 and/or cocaine on DJ1 protein expression in neuroblastoma cells (SK-N-MC. Gene expression and protein analysis of DJ1 was done on the HIV infected and/or cocaine treated SK-N-MC and compared to untreated cells using real time PCR, Western Blot and flow cytometry.Results: Gene expression and protein analysis indicated that there was a significant decrease in DJ1 expression in SK-N-MC chronically exposed to HIV-1 and/or cocaine.Conclusion: This is the first study to establish that DJ1 expression level in the neuronal cells significantly decreased in presence of HIV-1and/or cocaine indicating oxidative stress level of dopamine neurons.

  5. Molecular mechanisms by which HERV-K Gag interferes with HIV-1 Gag assembly and particle infectivity.

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    Monde, Kazuaki; Terasawa, Hiromi; Nakano, Yusuke; Soheilian, Ferri; Nagashima, Kunio; Maeda, Yosuke; Ono, Akira

    2017-04-26

    Human endogenous retroviruses (HERVs), the remnants of ancient retroviral infections, constitute approximately 8% of human genomic DNA. Since HERV-K Gag expression is induced by HIV-1 Tat in T cells, induced HERV-K proteins could affect HIV-1 replication. Indeed, previously we showed that HERV-K Gag and HIV-1 Gag coassemble and that this appears to correlate with the effect of HERV-K Gag expression on HIV-1 particle release and its infectivity. We further showed that coassembly requires both MA and NC domains, which presumably serve as scaffolding for Gag via their abilities to bind membrane and RNA, respectively. Notably, however, despite possessing these abilities, MLV Gag failed to coassemble with HIV-1 Gag and did not affect assembly and infectivity of HIV-1 particles. It is unclear how the specificity of coassembly is determined. Here, we showed that coexpression of HERV-K Gag with HIV-1 Gag changed size and morphology of progeny HIV-1 particles and severely diminished infectivity of such progeny viruses. We further compared HERV-K-MLV chimeric constructs to identify molecular determinants for coassembly specificity and for inhibition of HIV-1 release efficiency and infectivity. We found that the CA N-terminal domain (NTD) of HERV-K Gag is important for the reduction of the HIV-1 release efficiency, whereas both CA-NTD and major homology region of HERV-K Gag contribute to colocalization with HIV-1 Gag. Interestingly, these regions of HERV-K Gag were not required for reduction of progeny HIV-1 infectivity. Our results showed that HERV-K Gag CA is important for reduction of HIV-1 release and infectivity but the different regions within CA are involved in the effects on the HIV-1 release and infectivity. Altogether, these findings revealed that HERV-K Gag interferes the HIV-1 replication by two distinct molecular mechanisms.

  6. Matrin 3 is a co-factor for HIV-1 Rev in regulating post-transcriptional viral gene expression

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    Jeang Kuan-Teh

    2011-07-01

    Full Text Available Abstract Post-transcriptional regulation of HIV-1 gene expression is mediated by interactions between viral transcripts and viral/cellular proteins. For HIV-1, post-transcriptional nuclear control allows for the export of intron-containing RNAs which are normally retained in the nucleus. Specific signals on the viral RNAs, such as instability sequences (INS and Rev responsive element (RRE, are binding sites for viral and cellular factors that serve to regulate RNA-export. The HIV-1 encoded viral Rev protein binds to the RRE found on unspliced and incompletely spliced viral RNAs. Binding by Rev directs the export of these RNAs from the nucleus to the cytoplasm. Previously, Rev co-factors have been found to include cellular factors such as CRM1, DDX3, PIMT and others. In this work, the nuclear matrix protein Matrin 3 is shown to bind Rev/RRE-containing viral RNA. This binding interaction stabilizes unspliced and partially spliced HIV-1 transcripts leading to increased cytoplasmic expression of these viral RNAs.

  7. Human cyclin T1 expression ameliorates a T-cell-specific transcriptional limitation for HIV in transgenic rats, but is not sufficient for a spreading infection of prototypic R5 HIV-1 strains ex vivo

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    Littman Dan R

    2009-01-01

    Full Text Available Abstract Background Cells derived from native rodents have limits at distinct steps of HIV replication. Rat primary CD4 T-cells, but not macrophages, display a profound transcriptional deficit that is ameliorated by transient trans-complementation with the human Tat-interacting protein Cyclin T1 (hCycT1. Results Here, we generated transgenic rats that selectively express hCycT1 in CD4 T-cells and macrophages. hCycT1 expression in rat T-cells boosted early HIV gene expression to levels approaching those in infected primary human T-cells. hCycT1 expression was necessary, but not sufficient, to enhance HIV transcription in T-cells from individual transgenic animals, indicating that endogenous cellular factors are critical co-regulators of HIV gene expression in rats. T-cells from hCD4/hCCR5/hCycT1-transgenic rats did not support productive infection of prototypic wild-type R5 HIV-1 strains ex vivo, suggesting one or more significant limitation in the late phase of the replication cycle in this primary rodent cell type. Remarkably, we identify a replication-competent HIV-1 GFP reporter strain (R7/3 YU-2 Env that displays characteristics of a spreading, primarily cell-to-cell-mediated infection in primary T-cells from hCD4/hCCR5-transgenic rats. Moreover, the replication of this recombinant HIV-1 strain was significantly enhanced by hCycT1 transgenesis. The viral determinants of this so far unique replicative ability are currently unknown. Conclusion Thus, hCycT1 expression is beneficial to de novo HIV infection in a transgenic rat model, but additional genetic manipulations of the host or virus are required to achieve full permissivity.

  8. Mesenchymal stem cell derived hematopoietic cells are permissive to HIV-1 infection

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    Mondal Debasis

    2011-01-01

    Full Text Available Abstract Background Tissue resident mesenchymal stem cells (MSCs are multipotent, self-renewing cells known for their differentiation potential into cells of mesenchymal lineage. The ability of single cell clones isolated from adipose tissue resident MSCs (ASCs to differentiate into cells of hematopoietic lineage has been previously demonstrated. In the present study, we investigated if the hematopoietic differentiated (HD cells derived from ASCs could productively be infected with HIV-1. Results HD cells were generated by differentiating clonally expanded cultures of adherent subsets of ASCs (CD90+, CD105+, CD45-, and CD34-. Transcriptome analysis revealed that HD cells acquire a number of elements that increase their susceptibility for HIV-1 infection, including HIV-1 receptor/co-receptor and other key cellular cofactors. HIV-1 infected HD cells (HD-HIV showed elevated p24 protein and gag and tat gene expression, implying a high and productive infection. HD-HIV cells showed decreased CD4, but significant increase in the expression of CCR5, CXCR4, Nef-associated factor HCK, and Vpu-associated factor BTRC. HIV-1 restricting factors like APOBEC3F and TRIM5 also showed up regulation. HIV-1 infection increased apoptosis and cell cycle regulatory genes in HD cells. Although undifferentiated ASCs failed to show productive infection, HIV-1 exposure increased the expression of several hematopoietic lineage associated genes such as c-Kit, MMD2, and IL-10. Conclusions Considering the presence of profuse amounts of ASCs in different tissues, these findings suggest the possible role that could be played by HD cells derived from ASCs in HIV-1 infection. The undifferentiated ASCs were non-permissive to HIV-1 infection; however, HIV-1 exposure increased the expression of some hematopoietic lineage related genes. The findings relate the importance of ASCs in HIV-1 research and facilitate the understanding of the disease process and management strategies.

  9. Differences in APOBEC3G expression in CD4+ T helper lymphocyte subtypes modulate HIV-1 infectivity.

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    Michael L Vetter

    2009-02-01

    Full Text Available The cytidine deaminases APOBEC3G and APOBEC3F exert anti-HIV-1 activity that is countered by the HIV-1 vif protein. Based on potential transcription factor binding sites in their putative promoters, we hypothesized that expression of APOBEC3G and APOBEC3F would vary with T helper lymphocyte differentiation. Naive CD4+ T lymphocytes were differentiated to T helper type 1 (Th1 and 2 (Th2 effector cells by expression of transcription factors Tbet and GATA3, respectively, as well as by cytokine polarization. APOBEC3G and APOBEC3F RNA levels, and APOBEC3G protein levels, were higher in Th1 than in Th2 cells. T cell receptor stimulation further increased APOBEC3G and APOBEC3F expression in Tbet- and control-transduced, but not in GATA3-transduced, cells. Neutralizing anti-interferon-gamma antibodies reduced both basal and T cell receptor-stimulated APOBEC3G and APOBEC3F expression in Tbet- and control-transduced cells. HIV-1 produced from Th1 cells had more virion APOBEC3G, and decreased infectivity, compared to virions produced from Th2 cells. These differences between Th1- and Th2-produced virions were greater for viruses lacking functional vif, but also seen with vif-positive viruses. Over-expression of APOBEC3G in Th2 cells decreased the infectivity of virions produced from Th2 cells, and reduction of APOBEC3G in Th1 cells increased infectivity of virions produced from Th1 cells, consistent with a causal role for APOBEC3G in the infectivity difference. These results indicate that APOBEC3G and APOBEC3F levels vary physiologically during CD4+ T lymphocyte differentiation, that interferon-gamma contributes to this modulation, and that this physiological regulation can cause changes in infectivity of progeny virions, even in the presence of HIV-1 vif.

  10. Temporal expression of HIV-1 envelope proteins in baculovirus-infected insect cells: Implications for glycosylation and CD4 binding

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    Murphy, C.I.; Lennick, M.; Lehar, S.M.; Beltz, G.A.; Young, E. (Cambridge Bioscience Corporation, Worcester, MA (USA))

    1990-10-01

    Three different human immunodeficiency virus type I (HIV-1) envelope derived recombinant proteins and the full length human CD4 polypeptide were expressed in Spodoptera frugiperda (Sf9) cells. DNA constructs encoding CD4, gp120, gp160, and gp160 delta were cloned into the baculovirus expression vector pVL941 or a derivative and used to generate recombinant viruses in a cotransfection with DNA from Autographa californica nuclear polyhedrosis virus (AcMNPV). Western blotting of cell extracts of the recombinant HIV-1 proteins showed that for each construct two major bands specifically reacted with anti-HIV-1 envelope antiserum. These bands corresponded to glycosylated and nonglycosylated versions of the HIV proteins as determined by 3H-mannose labeling and tunicamycin treatment of infected cells. A time course of HIV envelope expression revealed that at early times post-infection (24 hours) the proteins were fully glycosylated and soluble in nonionic detergents. However, at later times postinfection (48 hours), expression levels of recombinant protein reached a maximum but most of the increase was due to a rise in the level of the nonglycosylated species, which was largely insoluble in nonionic detergents. Thus, it appears that Sf9 cells cannot process large amounts of glycosylated recombinant proteins efficiently. As a measure of biological activity, the CD4 binding ability of both glycosylated and nonglycosylated recombinant HIV envelope proteins was tested in a coimmunoprecipitation assay. The results showed that CD4 and the glycosylated versions of recombinant gp120 or gp160 delta specifically associated with one another in this analysis. Nonglycosylated gp120 or gp160 delta proteins from tunicamycin-treated cultures did immunoprecipitate with anti-HIV-1 antiserum but did not interact with CD4.

  11. Significant effects of antiretroviral therapy on global gene expression in brain tissues of patients with HIV-1-associated neurocognitive disorders.

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    Alejandra Borjabad

    2011-09-01

    Full Text Available Antiretroviral therapy (ART has reduced morbidity and mortality in HIV-1 infection; however HIV-1-associated neurocognitive disorders (HAND persist despite treatment. The reasons for the limited efficacy of ART in the brain are unknown. Here we used functional genomics to determine ART effectiveness in the brain and to identify molecular signatures of HAND under ART. We performed genome-wide microarray analysis using Affymetrix U133 Plus 2.0 Arrays, real-time PCR, and immunohistochemistry in brain tissues from seven treated and eight untreated HAND patients and six uninfected controls. We also determined brain virus burdens by real-time PCR. Treated and untreated HAND brains had distinct gene expression profiles with ART transcriptomes clustering with HIV-1-negative controls. The molecular disease profile of untreated HAND showed dysregulated expression of 1470 genes at p<0.05, with activation of antiviral and immune responses and suppression of synaptic transmission and neurogenesis. The overall brain transcriptome changes in these patients were independent of histological manifestation of HIV-1 encephalitis and brain virus burdens. Depending on treatment compliance, brain transcriptomes from patients on ART had 83% to 93% fewer dysregulated genes and significantly lower dysregulation of biological pathways compared to untreated patients, with particular improvement indicated for nervous system functions. However a core of about 100 genes remained similarly dysregulated in both treated and untreated patient brain tissues. These genes participate in adaptive immune responses, and in interferon, cell cycle, and myelin pathways. Fluctuations of cellular gene expression in the brain correlated in Pearson's formula analysis with plasma but not brain virus burden. Our results define for the first time an aberrant genome-wide brain transcriptome of untreated HAND and they suggest that antiretroviral treatment can be broadly effective in reducing

  12. Prokaryotic Expression and Purification of HIV-1 Vif and hAPOBEC3G, Preparation of Polyclonal Antibodies

    Institute of Scientific and Technical Information of China (English)

    Lan LI; Yi-shu YANG; Ze-lin LI; Yi ZENG

    2008-01-01

    To prepare HIV-1 Vif and hAPOBEC3G and to produce their antibodies, the full length gene fragment of HIV-1 Vif was amplified by PCR from a plasmid of HIV-1 NL4.3 cDNA, and the APOBEC3G gene was obtained by RT-PCR from the total RNA of H9 cells. The resulting DNA construct was cloned into a prokaryotic expression vector (pET-32a). Recombinant pET-vif and pET-APOBEC3G were expressed respectively in Eserichia coli BL21 (DE3) as an insoluble protein. The vector also contained a six-histidine tag at the C-terminus for convenient purification and detection. To express and purify the HIV-1 Vif and hAPOBEC3G in E. coli cells, the accuracy of inserted gene and specificity of proteins were detected by the two enzyme digestion method, SDS-PAGE, and Western blotting. Rabbits were then immunized by Vif or APOBEC3G protein and serum samples were tested by indirect ELISA to determine the level of antibodies. Immunoenzyme and immunofluorescence assays were performed to identify the specificity of polyclonal antibodies. The titer of the anti-Vif antibodies was 1:204800, and that of the anti-APOBEC3G antibodies was 1:102400. Thus the antibodies could detect the antigen expression in the cells, demonstrating that fusion proteins with high purity and their corresponding polyclonal antibodies with high titer and specificity were achieved.

  13. The porcine circovirus type 1 capsid gene promoter improves antigen expression and immunogenicity in a HIV-1 plasmid vaccine

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    Burger Marieta

    2011-02-01

    Full Text Available Abstract Background One of the promising avenues for development of vaccines against Human immunodeficiency virus type 1 (HIV-1 and other human pathogens is the use of plasmid-based DNA vaccines. However, relatively large doses of plasmid must be injected for a relatively weak response. We investigated whether genome elements from Porcine circovirus type 1 (PCV-1, an apathogenic small ssDNA-containing virus, had useful expression-enhancing properties that could allow dose-sparing in a plasmid vaccine. Results The linearised PCV-1 genome inserted 5' of the CMV promoter in the well-characterised HIV-1 plasmid vaccine pTHgrttnC increased expression of the polyantigen up to 2-fold, and elicited 3-fold higher CTL responses in mice at 10-fold lower doses than unmodified pTHgrttnC. The PCV-1 capsid gene promoter (Pcap alone was equally effective. Enhancing activity was traced to a putative composite host transcription factor binding site and a "Conserved Late Element" transcription-enhancing sequence previously unidentified in circoviruses. Conclusions We identified a novel PCV-1 genome-derived enhancer sequence that significantly increased antigen expression from plasmids in in vitro assays, and improved immunogenicity in mice of the HIV-1 subtype C vaccine plasmid, pTHgrttnC. This should allow significant dose sparing of, or increased responses to, this and other plasmid-based vaccines. We also report investigations of the potential of other circovirus-derived sequences to be similarly used.

  14. Differential expression of HIV-1 interfering factors in monocyte-derived macrophages stimulated with polarizing cytokines or interferons

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    Jiménez, Viviana Cobos; Booiman, Thijs; de Taeye, Steven W.; van Dort, Karel A.; Rits, Maarten A. N.; Hamann, Jörg; Kootstra, Neeltje A.

    2012-10-01

    HIV-1 replication in macrophages can be regulated by cytokines and infection is restricted in macrophages activated by type I interferons and polarizing cytokines. Here, we observed that the expression levels of the cellular factors Trim5α, CypA, APOBEC3G, SAMHD-1, Trim22, tetherin and TREX-1, and the anti-HIV miRNAs miR-28, miR-150, miR-223 and miR-382 was upregulated by IFN-α and IFN-β in macrophages, which may account for the inhibiting effect on viral replication and the antiviral state of these cells. Expression of these factors was also increased by IFN-γ +/- TNF-α, albeit to a lesser extent; yet, HIV-1 replication in these cells was not restricted at the level of proviral synthesis, indicating that these cellular factors only partially contribute to the observed restriction. IL-4, IL-10 or IL-32 polarization did not affect the expression of cellular factors and miRNAs, suggesting only a limited role for these cellular factors in restricting HIV-1 replication in macrophages.

  15. HIV-1 expression induces cyclin D1 expression and pRb phosphorylation in infected podocytes: cell-cycle mechanisms contributing to the proliferative phenotype in HIV-associated nephropathy

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    Husain Mohammad

    2002-09-01

    Full Text Available Abstract Background The aberrant cell-cycle progression of HIV-1-infected kidney cells plays a major role in the pathogenesis of HIV-associated nephropathy, however the mechanisms whereby HIV-1 induces infected glomerular podocytes or infected tubular epithelium to exit quiescence are largely unknown. Here, we ask whether the expression of HIV-1 genes in infected podocytes induces cyclin D1 and phospho-pRb (Ser780 expression, hallmarks of cyclin D1-mediated G1 → S phase progression. Results We assessed cyclin D1 and phospho-pRb (Ser780 expression in two well-characterized models of HIV-associated nephropathy pathogenesis: HIV-1 infection of cultured podocytes and HIV-1 transgenic mice (Tg26. Compared to controls, cultured podocytes expressing HIV-1 genes, and podocytes and tubular epithelium from hyperplastic nephrons in Tg26 kidneys, had increased levels of phospho-pRb (Ser780, a target of active cyclin D1/cyclin-dependent kinase-4/6 known to promote G1 → S phase progression. HIV-1-infected podocytes showed markedly elevated cyclin D1 mRNA and cyclin D1 protein, the latter of which did not down-regulate during cell-cell contact or differentiation, suggesting post-transcriptional stabilization of cyclin D1 protein levels by HIV-1. The selective suppression of HIV-1 transcription by the cyclin-dependent kinase inhibitor, flavopiridol, abrogated cyclin D1 expression, underlying the requirement for HIV-1 encoded products to induce cyclin D1. Indeed, HIV-1 virus deleted of nef failed to induce cyclin D1 mRNA to the level of other single gene mutant viruses. Conclusions HIV-1 expression induces cyclin D1 and phospho-pRb (Ser780 expression in infected podocytes, suggesting that HIV-1 activates cyclin D1-dependent cell-cycle mechanisms to promote proliferation of infected renal epithelium.

  16. CCR5 gene disruption via lentiviral vectors expressing Cas9 and single guided RNA renders cells resistant to HIV-1 infection.

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    Wang, Weiming; Ye, Chaobaihui; Liu, Jingjing; Zhang, Di; Kimata, Jason T; Zhou, Paul

    2014-01-01

    CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN) or Transcription activator-like effector nuclease (TALEN). In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9) and single guided RNAs (sgRNAs). We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a single round transduction of lentiviral vectors expressing Cas9 and CCR5 sgRNAs into HIV-1 susceptible human CD4+ cells yields high frequencies of CCR5 gene disruption. CCR5 gene-disrupted cells are not only resistant to R5-tropic HIV-1, including transmitted/founder (T/F) HIV-1 isolates, but also have selective advantage over CCR5 gene-undisrupted cells during R5-tropic HIV-1 infection. Importantly, using T7 endonuclease I assay we did not detect genome mutations at potential off-target sites that are highly homologous to these CCR5 sgRNAs in stably transduced cells even at 84 days post transduction. Thus we conclude that silencing of CCR5 via Cas9 and CCR5-specific sgRNAs could be a viable alternative strategy for engineering resistance against HIV-1.

  17. CCR5 gene disruption via lentiviral vectors expressing Cas9 and single guided RNA renders cells resistant to HIV-1 infection.

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    Weiming Wang

    Full Text Available CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN or Transcription activator-like effector nuclease (TALEN. In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9 and single guided RNAs (sgRNAs. We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a single round transduction of lentiviral vectors expressing Cas9 and CCR5 sgRNAs into HIV-1 susceptible human CD4+ cells yields high frequencies of CCR5 gene disruption. CCR5 gene-disrupted cells are not only resistant to R5-tropic HIV-1, including transmitted/founder (T/F HIV-1 isolates, but also have selective advantage over CCR5 gene-undisrupted cells during R5-tropic HIV-1 infection. Importantly, using T7 endonuclease I assay we did not detect genome mutations at potential off-target sites that are highly homologous to these CCR5 sgRNAs in stably transduced cells even at 84 days post transduction. Thus we conclude that silencing of CCR5 via Cas9 and CCR5-specific sgRNAs could be a viable alternative strategy for engineering resistance against HIV-1.

  18. The thalidomide analogue CC-3052 inhibits HIV-1 and tumour necrosis factor-alpha (TNF-α) expression in acutely and chronically infected cells in vitro

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    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

  19. HIV-1 Vif蛋白的体内表达及其生物学功能%In Vivo Expression and Biological Function of HIV-1 Vif Protein

    Institute of Scientific and Technical Information of China (English)

    张文艳; 孔维; 于湘晖

    2008-01-01

    目的 分别构建带有6His和mbp tag的HIV-1 Vif基因真核表达载体,在体内表达融合蛋白,并检测其生物学功能.方法 PCR扩增带有6His和mbp tag的HIV-1 Vif基因,克隆至真核表达载体VRl012上.将抗病毒因子APOBEC3G(A3G)分别与空载体VR1012、HIV-1野生型Vif/VR1012、Vif-mbp/VR1012和Vif-6His/VR1012共同转染293T细胞,检测Vif-mbp和Vif-6His的表达,并进行A3G体内降解试验.将A3G和/或可产生病毒的质粒HXB2Neo △ Aif分别与HIV-1野生型Vif/VR1012、Vif-mbp/VR1012和Vif-6His/VR1012共同转染293T细胞,通过A3G包装进病毒和Magi细胞感染试验,进一步检测HIV-1 Vif-mbp和Vif-6His融合蛋白的生物学功能.结果 重组表达质粒Vif-mbp/VR1012和Vif-6His/VR1012经双酶切鉴定证明构建正确.转染293T细胞48 h后,Vif-mbp和Vif-6His融合蛋白均有表达,但表达的Vff-mbp有不同程度的降解.Vif-6His可降解A3G,使其表达量下降至10%左右,而Vif-mbp几乎不能降解A3G.Vif-6His可阻止A3G包装进病毒颗粒中,而Vif-mbp无此功能.Vif-mbp可使HXB2Neo △ Vif病毒感染能力恢复至15%,而Vif-6His可使其恢复至86%.结论 已成功构建了带有6His和mbp tag的HIV-1 Vif基因真核表达载体,表达的Vif-mbp融合蛋白影响了Vif的生物学功能,但Vif-6His融合蛋白不影响Vif的生物学功能.

  20. Bacterial expression, correct membrane targeting and functional folding of the HIV-1 membrane protein Vpu using a periplasmic signal peptide.

    Science.gov (United States)

    Deb, Arpan; Johnson, William A; Kline, Alexander P; Scott, Boston J; Meador, Lydia R; Srinivas, Dustin; Martin-Garcia, Jose M; Dörner, Katerina; Borges, Chad R; Misra, Rajeev; Hogue, Brenda G; Fromme, Petra; Mor, Tsafrir S

    2017-01-01

    Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models.

  1. Bacterial expression, correct membrane targeting and functional folding of the HIV-1 membrane protein Vpu using a periplasmic signal peptide

    Science.gov (United States)

    Deb, Arpan; Johnson, William A.; Kline, Alexander P.; Scott, Boston J.; Meador, Lydia R.; Srinivas, Dustin; Martin-Garcia, Jose M.; Dörner, Katerina; Borges, Chad R.; Misra, Rajeev; Hogue, Brenda G.; Fromme, Petra

    2017-01-01

    Viral protein U (Vpu) is a type-III integral membrane protein encoded by Human Immunodeficiency Virus-1 (HIV- 1). It is expressed in infected host cells and plays several roles in viral progeny escape from infected cells, including down-regulation of CD4 receptors. But key structure/function questions remain regarding the mechanisms by which the Vpu protein contributes to HIV-1 pathogenesis. Here we describe expression of Vpu in bacteria, its purification and characterization. We report the successful expression of PelB-Vpu in Escherichia coli using the leader peptide pectate lyase B (PelB) from Erwinia carotovora. The protein was detergent extractable and could be isolated in a very pure form. We demonstrate that the PelB signal peptide successfully targets Vpu to the cell membranes and inserts it as a type I membrane protein. PelB-Vpu was biophysically characterized by circular dichroism and dynamic light scattering experiments and was shown to be an excellent candidate for elucidating structural models. PMID:28225803

  2. The variances of Sp1 and NF-κB elements correlate with the greater capacity of Chinese HIV-1 B′-LTR for driving gene expression

    OpenAIRE

    2016-01-01

    The 5′ end of HIV-1 long terminal repeat (LTR) serves as a promoter that plays an essential role in driving viral gene transcription. Manipulation of HIV-1 LTR provides a potential therapeutic strategy for suppressing viral gene expression or excising integrated provirus. Subtype-specific genetic diversity in the LTR region has been observed. The minor variance of LTR, particularly in the transcription factor binding sites, can have a profound impact on its activity. However, the LTR profiles...

  3. Truncation and expression of HIV-1 trans-membrane protein gp41%HIV-1跨膜蛋白gp41的截短及表达

    Institute of Scientific and Technical Information of China (English)

    端义坤; 张涛; 余模松

    2003-01-01

    HIV-1跨膜蛋白gp41进行截短,在大肠杆菌中进行表达并纯化.PCR扩增gp41的部分编码基因,回收的PCR产物纯化后克隆到连接载体pGEM-T上,然后用EcoR I和Sa1 I切下目的基因,并构建到表达载体pGEX-4T3上,导入宿主细胞BL21(DE3),用IPTG诱导表达,表达产物用亲和层析进行纯化并作相应鉴定.截短的HIV-1跨膜蛋白gp41能直接在大肠杆菌内进行表达,利用亲和层析能方便地将目的蛋白进行纯化,为跨膜蛋白的进一步应用打下基础.

  4. HIV-1 infected lymphoid organs upregulate expression and release of the cleaved form of uPAR that modulates chemotaxis and virus expression.

    Directory of Open Access Journals (Sweden)

    Manuela Nebuloni

    Full Text Available Cell-associated receptor for urokinase plasminogen activator (uPAR is released as both full-length soluble uPAR (suPAR and cleaved (c-suPAR form that maintain ability to bind to integrins and other receptors, thus triggering and modulating cell signaling responses. Concerning HIV-1 infection, plasma levels of suPAR have been correlated with the severity of disease, levels of immune activation and ineffective immune recovery also in individuals receiving combination anti-retroviral therapy (cART. However, it is unknown whether and which suPAR forms might contribute to HIV-1 induced pathogenesis and to the related state of immune activation. In this regard, lymphoid organs represent an import site of chronic immune activation and virus persistence even in individuals receiving cART. Lymphoid organs of HIV-1(+ individuals showed an enhanced number of follicular dendritic cells, macrophages and endothelial cells expressing the cell-associated uPAR in comparison to those of uninfected individuals. In order to investigate the potential role of suPAR forms in HIV-1 infection of secondary lymphoid organs, tonsil histocultures were established from HIV-1 seronegative individuals and infected ex vivo with CCR5- and CXCR4-dependent HIV-1 strains. The levels of suPAR and c-suPAR were significantly increased in HIV-infected tonsil histocultures supernatants in comparison to autologous uninfected histocultures. Supernatants from infected and uninfected cultures before and after immunodepletion of suPAR forms were incubated with the chronically infected promonocytic U1 cell line characterized by a state of proviral latency in unstimulated conditions. In the contest of HIV-conditioned supernatants we established that c-suPAR, but not suPAR, inhibited chemotaxis and induced virus expression in U1 cells. In conclusion, lymphoid organs are an important site of production and release of both suPAR and c-suPAR, this latter form being endowed with the capacity of

  5. Is the central nervous system a reservoir of HIV-1?

    Science.gov (United States)

    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

  6. HIV-1 Gp41 recombinant antigen: expression and immunoreactivity analysis%HIV-1gp41重组抗原的表达及其免疫反应性检测

    Institute of Scientific and Technical Information of China (English)

    张昕; 梁权; 王缦

    2012-01-01

    为了在大肠杆菌中表达具有良好免疫反应性的HIV-1 gp41重组抗原,本实验运用基因工程技术,经PCR扩增gp41的主要抗原表位序列,BamH I、XhoI双酶切后与E3质粒连接,转化克隆宿主菌DH5α,再提取重组质粒进一步转化表达宿主菌BL21(DE3),经IPTG诱导表达重组蛋白,纯化后标记HRP,通过双抗原夹心酶联免疫方法检测其免疫反应性和特异性.结果表明,获得的HIV-1 gp41重组抗原能够与相应抗体特异性结合,与多种无关抗体间无交叉反应,对825份HIV阴性标本检测无错检.检测结果说明该重组抗原具有良好的免疫反应性,在HIV-1抗体诊断试剂中具有潜在的应用价值,为进一步研究gp41抗原奠定了基础.%To express HIV-1 transmembrane glycoprotein gp41 that has fine immunoreactivity in prokaryotic system of E. coli, the target DNA sequence encoding for major epitopes of HIV-1 gp41 was amplified through PCR. The product was digested by BamH I and Xho I , and inserted into E3 vector. Then the joint product was transported into cloning host DH5a from which we extracted recombinant plasmid that was further transported into BL21(DE3) host. The recombinant protein was expressed when induced with IPTG. And after being purified and labelled with HRP, the immunoreactivity and specificity of the protein was evaluated through double-antigen sandwich ELISA. Results proved that, the HIV-1 gp41 recombinant antigen bound corresponding antibody specifically, and had no cross reactivity with various irrelevant antibodies and showed no false positive results when testing with 825 HIV negative specimens. So, this recombinant antigen has fine immunoreactivity and potentcial application value in HIV antibody detection kit.

  7. Hyperdopaminergic tone in HIV-1 protein treated rats and cocaine sensitization

    Science.gov (United States)

    Ferris, Mark J.; Frederick-Duus, Danielle; Fadel, Jim; Mactutus, Charles F; Booze, Rosemarie M.

    2013-01-01

    In the United States, one-third of infected individuals contracted Human Immunodeficiency Virus-1 (HIV-1) via injecting drugs with contaminated needles or through risky behaviors associated with drug use. Research demonstrates concomitant administration of psychostimulants and HIV-1-proteins damage neurons to a greater extent than viral proteins or the drug alone. To model the onset of HIV-1-infection in relation to a history of drug use, the current research compared behavior and extracellular dopamine and metabolite levels following Tat1–86 infusions in animals with and without a history of cocaine (Coc) experience (10 mg/kg; i.p.; 1 injection/day × 9 days). Animals receiving a behaviorally sensitizing regimen of Coc demonstrated a decrease in extracellular dopamine concentration in the nucleus accumbens, consistent with evidence describing up-regulation of dopamine transporter uptake. Contrary to this effect, Tat1–86 microinfusion into the nucleus accumbens following the sensitizing regimen of Coc caused a significant increase in extracellular dopamine levels (nM) within 48 h with no difference in percent of baseline response to Coc. After 72 h, Tat + Coc treated animals demonstrated a blunted effect on potassium-stimulated extracellular dopamine release (percent of baseline) with a corresponding decrease in expression of behavioral sensitization to Coc challenge. A persistent decrease in extracellular dopamine metabolite levels was found across all time-points in Tat-treated animals, regardless of experience with Coc. The current study provides evidence for divergent neurochemical and behavioral outcomes following Tat-treatment; contingent upon experience with Coc. PMID:20796175

  8. Engineering and Validation of a Vector for Concomitant Expression of Rare Transfer RNA (tRNA) and HIV-1 nef Genes in Escherichia coli.

    Science.gov (United States)

    Mualif, Siti Aisyah; Teow, Sin-Yeang; Omar, Tasyriq Che; Chew, Yik Wei; Yusoff, Narazah Mohd; Ali, Syed A

    2015-01-01

    Relative ease in handling and manipulation of Escherichia coli strains make them primary candidate to express proteins heterologously. Overexpression of heterologous genes that contain codons infrequently used by E. coli is related with difficulties such as mRNA instability, early termination of transcription and/or translation, deletions and/or misincorporation, and cell growth inhibition. These codon bias -associated problems are addressed by co-expressing ColE1-compatible, rare tRNA expressing helper plasmids. However, this approach has inadequacies, which we have addressed by engineering an expression vector that concomitantly expresses the heterologous protein of interest, and rare tRNA genes in E. coli. The expression vector contains three (argU, ileY, leuW) rare tRNA genes and a useful multiple cloning site for easy in-frame cloning. To maintain the overall size of the parental plasmid vector, the rare tRNA genes replaced the non-essential DNA segments in the vector. The cloned gene is expressed under the control of T7 promoter and resulting recombinant protein has a C-terminal 6His tag for IMAC-mediated purification. We have evaluated the usefulness of this expression vector by expressing three HIV-1 genes namely HIV-1 p27 (nef), HIV-1 p24 (ca), and HIV-1 vif in NiCo21(DE3) E.coli and demonstrated the advantages of using expression vector that concomitantly expresses rare tRNA and heterologous genes.

  9. Alteration of Methamphetamine-induced stereotypic behaviour in transgenic mice expressing HIV-1 envelope protein gp120.

    Science.gov (United States)

    Roberts, Amanda J; Maung, Ricky; Sejbuk, Natalia E; Ake, Christopher; Kaul, Marcus

    2010-02-15

    The use of drugs for recreational purposes, in particular Methamphetamine, is associated with an increased risk of infection with human immunodeficiency virus (HIV)-1. HIV-1 infection in turn can lead to HIV-associated neurological disorders (HAND) that range from mild cognitive and motor impairment to HIV-associated dementia (HAD). Interestingly, post mortem brain specimens from HAD patients and transgenic (tg) mice expressing the viral envelope protein gp120 in the central nervous system display similar neuropathological signs. In HIV patients, the use of Methamphetamine appears to aggravate neurocognitive alterations. In the present study, we injected HIV/gp120tg mice and non-transgenic littermate control animals with Methamphetamine dissolved in Saline or Saline vehicle and assessed locomotion and stereotyped behaviour. We found that HIVgp120-transgenic mice differ significantly from non-transgenic controls in certain domains of their behavioural response to Methamphetamine. Thus this experimental model system may be useful to further study the mechanistic interaction of both the viral envelope protein and the psychostimulant drug in behavioural alterations and neurodegenerative disease.

  10. 2B4 expression on natural killer cells increases in HIV-1 infected patients followed prospectively during highly active antiretroviral therapy

    DEFF Research Database (Denmark)

    Ostrowski, S R; Ullum, H; Pedersen, Bente Klarlund

    2005-01-01

    Human immunodeficiency virus (HIV)-1 infection influences natural killer (NK) cell expression of inhibitory NK receptors and activating natural cytotoxicity receptors. It is unknown whether expression of the co-stimulatory NK cell receptor 2B4 (CD244) on NK cells and CD3+ CD8+ cells are affected...... expression on CD3- CD16+ NK cells and CD3+ CD8+ cells, proviral-DNA and plasma soluble tumour necrosis factor receptor (sTNFr)-II were investigated 6-monthly. For comparison, 2B4 expression was investigated in 20 healthy individuals. The concentration of 2B4+ NK cells was initially reduced in HIV-1 infected...... patients (P cells in HIV-1 infected patients was normal and did not change during follow-up. The relative fluorescence intensity (RFI) of 2B4 increased on both NK cells and CD3+ CD8+ cells during...

  11. Association of Tat with promoters of PTEN and PP2A subunits is key to transcriptional activation of apoptotic pathways in HIV-infected CD4+ T cells.

    Directory of Open Access Journals (Sweden)

    Nayoung Kim

    2010-09-01

    Full Text Available Apoptosis in HIV-1-infected CD4+ primary T cells is triggered by the alteration of the PI3K and p53 pathways, which converge on the FOXO3a transcriptional activator. Tat alone can cause activation of FOXO3a and of its proapoptotic target genes. To understand how Tat affects this pathway, we carried out ChIP-Chip experiments with Tat. Tat associates with the promoters of PTEN and two PP2A subunit genes, but not with the FOXO3a promoter. PTEN and PP2A encode phosphatases, whose levels and activity are increased when Tat is expressed. They counteract phosphorylation of Akt1 and FOXO3a, and so activate transcriptional activity of FOXO3a. FOXO3a promotes increased transcription of Egr-1, which can further stimulate the transcription of PTEN, thereby reinforcing the pathway that leads to FOXO3a transcriptional activation. RNAi experiments support the role of PTEN and PP2A in the initiation of the Tat-mediated cascade, which is critical to apoptosis. The increased accumulation of PTEN and PP2A subunit mRNAs during Tat expression is more likely to be the result of increased transcription initiation and not relief of promoter-proximal pausing of RNAPII. The Tat-PTEN and -PP2A promoter interactions provide a mechanistic explanation of Tat-mediated apoptosis in CD4+ T cells.

  12. Molecular Characterization of Heterologous HIV-1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

    Directory of Open Access Journals (Sweden)

    Joan Joseph

    2010-01-01

    Full Text Available Mycobacterium bovis Bacillus Calmette-Guérin (BCG as a live vector of recombinant bacterial vaccine is a promising system to be used. In this study, we evaluate the disrupted expression of heterologous HIV-1gp120 gene in BCG Pasteur host strain using replicative vectors pMV261 and pJH222. pJH222 carries a lysine complementing gene in BCG lysine auxotrophs. The HIV-1 gp120 gene expression was regulated by BCG hsp60 promoter (in plasmid pMV261 and Mycobacteria spp. α-antigen promoter (in plasmid pJH222. Among 14 rBCG:HIV-1gp120 (pMV261 colonies screened, 12 showed a partial deletion and two showed a complete deletion. However, deletion was not observed in all 10 rBCG:HIV-1gp120 (pJH222 colonies screened. In this study, we demonstrated that E. coli/Mycobacterial expression vectors bearing a weak promoter and lysine complementing gene in a recombinant lysine auxotroph of BCG could prevent genetic rearrangements and disruption of HIV 1gp120 gene expression, a key issue for engineering Mycobacterial based vaccine vectors.

  13. HIV-1 alters neural and glial progenitor cell dynamics in the central nervous system: coordinated response to opiates during maturation.

    Science.gov (United States)

    Hahn, Yun Kyung; Podhaizer, Elizabeth M; Hauser, Kurt F; Knapp, Pamela E

    2012-12-01

    HIV-associated neurocognitive disorders (HANDs) are common sequelae of human immunodeficiency virus (HIV) infection, even when viral titers are well controlled by antiretroviral therapy. Evidence in patients and animal models suggests that neurologic deficits are increased during chronic opiate exposure. We have hypothesized that central nervous system (CNS) progenitor cells in both adult and developing CNS are affected by HIV infection and that opiates exacerbate these effects. To examine this question, neural progenitors were exposed to HIV-1 Tat(1-86) in the developing brain of inducible transgenic mice and in vitro. We examined whether Tat affected the proliferation or balance of progenitor populations expressing nestin, Sox2, and Olig2. Disease relevance was further tested by exposing human-derived progenitors to supernatant from HIV-1 infected monocytes. Studies concentrated on striatum, a region preferentially targeted by HIV and opiates. Results were similar among experimental paradigms. Tat or HIV exposure reduced the proliferation of undifferentiated (Sox2(+)) progenitors and oligodendroglial (Olig2(+)) progenitors. Coexposure to morphine exacerbated the effects of Tat or HIV-1(SF162) supernatant, but partially reversed HIV-1(IIIB) supernatant effects. Populations of Sox2(+) and Olig2(+) cells were also reduced by Tat exposure, although progenitor survival was unaffected. In rare instances, p24 immunolabeling was detected in viable human progenitors by confocal imaging. The vulnerability of progenitors is likely to distort the dynamic balance among neuron/glial populations as the brain matures, perhaps contributing to reports that neurologic disease is especially prevalent in pediatric HIV patients. Pediatric disease is atypical in developed regions but remains a serious concern in resource-limited areas where infection occurs commonly at birth and through breast feeding.

  14. Genetic selection for context-dependent stochastic phenotypes: Sp1 and TATA mutations increase phenotypic noise in HIV-1 gene expression.

    Directory of Open Access Journals (Sweden)

    Kathryn Miller-Jensen

    Full Text Available The sequence of a promoter within a genome does not uniquely determine gene expression levels and their variability; rather, promoter sequence can additionally interact with its location in the genome, or genomic context, to shape eukaryotic gene expression. Retroviruses, such as human immunodeficiency virus-1 (HIV, integrate their genomes into those of their host and thereby provide a biomedically-relevant model system to quantitatively explore the relationship between promoter sequence, genomic context, and noise-driven variability on viral gene expression. Using an in vitro model of the HIV Tat-mediated positive-feedback loop, we previously demonstrated that fluctuations in viral Tat-transactivating protein levels generate integration-site-dependent, stochastically-driven phenotypes, in which infected cells randomly 'switch' between high and low expressing states in a manner that may be related to viral latency. Here we extended this model and designed a forward genetic screen to systematically identify genetic elements in the HIV LTR promoter that modulate the fraction of genomic integrations that specify 'Switching' phenotypes. Our screen identified mutations in core promoter regions, including Sp1 and TATA transcription factor binding sites, which increased the Switching fraction several fold. By integrating single-cell experiments with computational modeling, we further investigated the mechanism of Switching-fraction enhancement for a selected Sp1 mutation. Our experimental observations demonstrated that the Sp1 mutation both impaired Tat-transactivated expression and also altered basal expression in the absence of Tat. Computational analysis demonstrated that the observed change in basal expression could contribute significantly to the observed increase in viral integrations that specify a Switching phenotype, provided that the selected mutation affected Tat-mediated noise amplification differentially across genomic contexts. Our study

  15. Cloning and Prokaryotic Expression of HIV-1 Vif Gene%HIV-1 Vif基因的克隆与原核表达

    Institute of Scientific and Technical Information of China (English)

    朱可彤; 杜娟; 王小丹; 郭博; 孔维; 于湘晖

    2008-01-01

    目的 克隆HIV-1 Vif基因编码区序列,并在原核细胞中表达.方法 构建原核表达载体pMRI,将Vif基因序列克隆至该载体中,转化大肠杆菌BL21(DE3),经IPTG诱导,菌体裂解后获得特异性表达蛋白,用组氨酸标签特异性亲和树脂分离纯化该蛋白,并经SDS-PAGE及Western blot鉴定.结果 表达质粒pMRI-Vif经双酶切,可见约600 bp的Vif基因片段,测序结果 证明质粒构建正确.在大肠杆菌BL21(DE3)中高效表达了可溶性Vif蛋白,纯化后经凝胶自动扫捕分析,纯度达85%以上,蛋白浓度约为1 g/L.纯化产物具有良好的抗原特异性.结论 在大肠杆菌中高效表达了可溶性Vif蛋白.

  16. Fused-expression and characterization of catalase-TAT%Catalase-TAT的融合表达与表征

    Institute of Scientific and Technical Information of China (English)

    李仁宽; 孙立国; 吕元辉; 刘树滔; 饶平凡

    2012-01-01

    利用RT-PCR技术从人的肝细胞中克隆出成熟蛋白过氧化氢酶(catalase)的基因,通过PCR将其与TAT基因融合形成融合基因(catalase-TAT);将catalase-TAT基因构建到表达质粒pET21a(+)中,转入大肠杆菌Rosetta2 (DE3);通过IPTG诱导,转化子成功表达出catalase-TAT融合蛋白.重组菌发酵菌体破碎液经过硫酸铵沉降和Sp-5pw阳离子交换色谱,分离得到电泳纯的目的蛋白,其纯化倍数为18.51倍;经理化性质分析确定了此融合蛋白的最适pH和温度稳定性;细胞实验表明融合蛋白catalase-TAT能够明显提高胞内的过氧化氢酶活性.%Human catalase gene was amplified from liver cells via RT - PCR and fused to TAT. The catalase - TAT was cloned into the expression vector pET21a ( + ) and transformed into Rosettal ( DE3). After induction with IPTG, the recombinant catalase - TAT fusion protein was successfully expressed. The lecombinant bacteria were sonicated and the targeted protein was purified to a single band on SDS - PAGE after ammonium sulfate precipitation and Sp -5pw cation exchange chromatogra-phy, with the purification factor of 18. 51. With physical and chemical analyses, the optimum pH and thermal stability of the fusion protein was determined.

  17. The variances of Sp1 and NF-κB elements correlate with the greater capacity of Chinese HIV-1 B′-LTR for driving gene expression

    Science.gov (United States)

    Qu, Di; Li, Chuan; Sang, Feng; Li, Qiang; Jiang, Zhi-Qiang; Xu, Li-Ran; Guo, Hui-Jun; Zhang, Chiyu; Wang, Jian-Hua

    2016-01-01

    The 5′ end of HIV-1 long terminal repeat (LTR) serves as a promoter that plays an essential role in driving viral gene transcription. Manipulation of HIV-1 LTR provides a potential therapeutic strategy for suppressing viral gene expression or excising integrated provirus. Subtype-specific genetic diversity in the LTR region has been observed. The minor variance of LTR, particularly in the transcription factor binding sites, can have a profound impact on its activity. However, the LTR profiles from major endemic Chinese subtypes are not well characterized. Here, by characterizing the sequences and functions of LTRs from endemic Chinese HIV-1 subtypes, we showed that nucleotide variances of Sp1 core promoter and NF-κB element are associated with varied LTR capacity for driving viral gene transcription. The greater responsiveness of Chinese HIV-1 B′-LTR for driving viral gene transcription upon stimulation is associated with an increased level of viral reactivation. Moreover, we demonstrated that the introduction of CRISPR/dead Cas9 targeting Sp1 or NF-κB element suppressed viral gene expression. Taken together, our study characterized LTRs from endemic HIV-1 subtypes in China and suggests a potential target for the suppression of viral gene expression and a novel strategy that facilitates the accomplishment of a functional cure. PMID:27698388

  18. HIV-1 vaccines

    Science.gov (United States)

    Excler, Jean-Louis; Robb, Merlin L; Kim, Jerome H

    2014-01-01

    The development of a safe and effective preventive HIV-1 vaccine remains a public health priority. Despite scientific difficulties and disappointing results, HIV-1 vaccine clinical development has, for the first time, established proof-of-concept efficacy against HIV-1 acquisition and identified vaccine-associated immune correlates of risk. The correlate of risk analysis showed that IgG antibodies against the gp120 V2 loop correlated with decreased risk of HIV infection, while Env-specific IgA directly correlated with increased risk. The development of vaccine strategies such as improved envelope proteins formulated with potent adjuvants and DNA and vectors expressing mosaics, or conserved sequences, capable of eliciting greater breadth and depth of potentially relevant immune responses including neutralizing and non-neutralizing antibodies, CD4+ and CD8+ cell-mediated immune responses, mucosal immune responses, and immunological memory, is now proceeding quickly. Additional human efficacy trials combined with other prevention modalities along with sustained funding and international collaboration remain key to bring an HIV-1 vaccine to licensure. PMID:24637946

  19. HIV-1包膜蛋白gp41优势抗原的构建及可溶性表达%Construction and Prokaryotic Expression of Soluble HIV-1 gp41 Dominant Epitopes

    Institute of Scientific and Technical Information of China (English)

    杜刚; 江蒙蒙; 尹林; 王宏萍; 周晓明

    2011-01-01

    目的:筛选1型人免疫缺陷病毒(HIV-1)中国流行株中包膜蛋白gp41的优势抗原片段,构建具有区域流行代表性的HIV-1 gp41重组抗原,为改进现有HIV-1初筛试剂盒中使用的同类抗原奠定基础.方法:利用免疫斑点杂交和生物信息学方法,从收集自重庆、广州、上海的区域代表性150份HIV-1感染者血清标本中筛选gp41抗原性强的候选样本,利用RT-PCR及巢式PCR方法扩增包含重要抗原表位决定蔟的gp41基因片段,与原核表达载体pQE30连接,转化大肠杆菌M15构建gp41重组抗原表达菌株,表达后经亲和层析纯化、SDS-PAGE和Western印迹鉴定.结果:兔源HRP标记的gp41多抗能识别标本中gp41抗原性差异,得到候选样本,扩增包含gp41主要抗原表位片段;构建了包含gp41抗原表达簇的重组原核表达质粒,表达、纯化后经His标签抗体Western印迹鉴定为阳性.结论:高纯度的重组优势gp41抗原的构建和鉴定,为进一步改进现有HIV初筛诊断奠定了基础.%Objective: To prepare the major antigen fragment of gp41 of HIV-1 based on main epidemic strains in China and to construct representative gp41 recombinant antigen of HIV-1 for further improving the efficacy of current HIV screening test. Methods: Combined with viral load of each sample, dot blot and bioinfomatic analysis were to identify two candidate samples from 150 HIV-1 postive serums collected from Chongqing, Guangzhou and Shanghai. Subsequently, RT-PCR and nested PCR were performed to synthesize gp41 epitope-specific sequences, then the cloned fragments containing dominant gp41 epitopes cotransformed with the backbone vector pQE30 into E.coil M15 was performed to obtain recombinant gp41 expression strain. Results: Rabbit HRP-labelled anti-gp41 polyclonal antibody could recognize the different gp41 intensity in 150 samples, from which the result led to the successful selection of two candidate samples. Then we constructed the recombinant

  20. CCR5 Gene Disruption via Lentiviral Vectors Expressing Cas9 and Single Guided RNA Renders Cells Resistant to HIV-1 Infection

    OpenAIRE

    2014-01-01

    CCR5, a coreceptor for HIV-1 entry, is a major target for drug and genetic intervention against HIV-1. Genetic intervention strategies have knocked down CCR5 expression levels by shRNA or disrupted the CCR5 gene using zinc finger nucleases (ZFN) or Transcription activator-like effector nuclease (TALEN). In the present study, we silenced CCR5 via CRISPR associated protein 9 (Cas9) and single guided RNAs (sgRNAs). We constructed lentiviral vectors expressing Cas9 and CCR5 sgRNAs. We show that a...

  1. HIV-1 gp41的酵母表面展示及表达优化%Yeast Surface Display of HIV-1 gp41 and Expression Enhancement

    Institute of Scientific and Technical Information of China (English)

    向柱方; 林影; 叶波; 韩双艳; 赵树进

    2008-01-01

    以His标签检测蛋白的表达,利用酿酒酵母表面展示系统,成功地将HIV-1 gp41片段锚定在酵母表面,并检测到gp41的活性.以pMD18T-gp41为模板,通过PCR技术克隆了gp41基因,将gp41基因通过双酶切连接到载体pICAS-His上,构建了gp41酵母表面展示载体,并将其转化至酿酒酵母(Saccharomyces cerevisiae)MT8-1中.重组菌经培养,利用免疫荧光染色方法进行染色,显微镜观察发现重组酵母细胞表面有绿色荧光,流式细胞仪结果进一步证实gp41正确折叠展示于酵母细胞表面.采用不同浓度的葡萄糖培养基进行表达优化.当葡萄糖浓度为1%时,82.46%的酵母细胞表达了gp41抗原;随着葡萄糖浓度升高,蛋白表达受到抑制.

  2. Three distinct stages of lens opacification in transgenic mice expressing the HIV-1 protease.

    Science.gov (United States)

    Tumminia, S J; Clark, J I; Richiert, D M; Mitton, K P; Duglas-Tabor, Y; Kowalak, J A; Garland, D L; Russell, P

    2001-02-01

    Scanning electron microscopy of the lenses from transgenic mice (TG(72)) containing the HIV-1 protease linked to the lens alphaA-crystallin promoter showed structural changes around postnatal day 16. Frank opacification of the lens was observed at day 24. To relate the biochemical and biophysical changes that occur during the process of cataract development, high-resolution two-dimensional gel electrophoresis (2D), quantitative image analysis and ion measurements were carried out on lenses from postnatal day 10 and on days 15-24. The phase separation temperature (Tc), a measure of molecular interactions between proteins, was also determined for normal and transgenic lenses. A comparison of the transgenic and normal lenses on day 10 revealed no significant differences in any of the measured parameters. However, starting around day 16 or the first stage of observed structural changes, the TG(72)crystallin profiles of the alphaA- alphaB-, betaA3-, betaA4-, betaB3 and one gamma-crystallin began to deviate from the normal. By postnatal day 20, a second stage was initiated with an influx of calcium and sodium ions that was accompanied by modifications of betaB1- and betaB2-crystallin. In the third and final stage of the cataract process, a large increase in the proteolysis of crystallins was accompanied by the appearance of the frank cataract on day 24. The Tc initially increased in all of the mouse lenses until just prior to eyelid opening. After that time, the Tc decreased in all lenses. Although the Tc continued to decrease in the normal lenses with age, for the homozygous transgenic mice it exhibited a dramatic increase that began on day 20. Thus, in the TG(72)transgenic mouse, cataract formation occurs in a three-stage process. Tc and other biophysical parameters previously measured appeared to be insensitive to the modifications that occur during stage 1. However, during the second stage of cataract formation, there was a correspondence between abnormal Tc and the

  3. Engineering HIV-1-resistant T-cells from short-hairpin RNA-expressing hematopoietic stem/progenitor cells in humanized BLT mice.

    Directory of Open Access Journals (Sweden)

    Gene-Errol E Ringpis

    Full Text Available Down-regulation of the HIV-1 coreceptor CCR5 holds significant potential for long-term protection against HIV-1 in patients. Using the humanized bone marrow/liver/thymus (hu-BLT mouse model which allows investigation of human hematopoietic stem/progenitor cell (HSPC transplant and immune system reconstitution as well as HIV-1 infection, we previously demonstrated stable inhibition of CCR5 expression in systemic lymphoid tissues via transplantation of HSPCs genetically modified by lentiviral vector transduction to express short hairpin RNA (shRNA. However, CCR5 down-regulation will not be effective against existing CXCR4-tropic HIV-1 and emergence of resistant viral strains. As such, combination approaches targeting additional steps in the virus lifecycle are required. We screened a panel of previously published shRNAs targeting highly conserved regions and identified a potent shRNA targeting the R-region of the HIV-1 long terminal repeat (LTR. Here, we report that human CD4(+ T-cells derived from transplanted HSPC engineered to co-express shRNAs targeting CCR5 and HIV-1 LTR are resistant to CCR5- and CXCR4- tropic HIV-1-mediated depletion in vivo. Transduction with the combination vector suppressed CXCR4- and CCR5- tropic viral replication in cell lines and peripheral blood mononuclear cells in vitro. No obvious cytotoxicity or interferon response was observed. Transplantation of combination vector-transduced HSPC into hu-BLT mice resulted in efficient engraftment and subsequent stable gene marking and CCR5 down-regulation in human CD4(+ T-cells within peripheral blood and systemic lymphoid tissues, including gut-associated lymphoid tissue, a major site of robust viral replication, for over twelve weeks. CXCR4- and CCR5- tropic HIV-1 infection was effectively inhibited in hu-BLT mouse spleen-derived human CD4(+ T-cells ex vivo. Furthermore, levels of gene-marked CD4(+ T-cells in peripheral blood increased despite systemic infection with either

  4. HIV-1gp41蛋白的表达及其免疫反应性%Expression and purification of recombinant HIV-1 gp41 protein and determination of its immunoreactivity

    Institute of Scientific and Technical Information of China (English)

    梁权; 罗春贞; 毛培菊; 王缦

    2011-01-01

    Objective Expressions of HIV-1 gp41 antigen for in-vitro immunoassay.Methods HIV-1 gp41 gene was amplified by PCR by using the plasmid X1 as a template, and then inserted into the plasmid E1 to construct recombinant plasmids E1-1. The expression of the recombinant plasmid in competent E.coli cell Bl21DE3 was induced with IPTG and analyzed with SDS-PAGE. After being purified by Ni-NTA affinity chromatography, the recombinant protein was further evaluated with ELISA for their functional characteristics.Results The result from SDS-PAGE showed expression of E1-1 in the competent E.coli cell. The purity of the purified recombinant protein was over 95%, and the protein has excellent immunoreactivity and specificity with ELISA.Conclusions Recombinant protein E1-1 can be expressed with a high immunoactivity, which can be qualified for HIV ELISA production.%目的 高效表达HIV-1 gp41基因片段,满足生产HIV体外检测试剂的需要.方法 以含HIV-1 gp41基因的质粒X1为模板,采用PCR方法扩增出gp41基因,克隆入E1载体构建重组表达质粒E1-1,转化E.coli BL21DE3感受态细胞,经异丙基-β-D-硫代半乳糖苷(IPTG)诱导后,使用镍螯合琼脂糖亲和层析柱(Ni-NTA Agaros)纯化重组蛋白,通过ELISA法检测重组蛋白的免疫反应性和特异性.结果 SDS -PAGE鉴定结果表明,重组E1-1蛋白获得了正确的表达;纯化的重组E1-1蛋白纯度>95%; ELISA检测结果表明,重组E1-1蛋白具有较优的免疫反应性和特异性.结论 成功表达出具有较高免疫反应性的重组E1-1蛋白,可应用于HIV体外检测试剂.

  5. Induction of cyclooxygenase-2 expression during HIV-1-infected monocyte-derived macrophage and human brain microvascular endothelial cell interactions

    NARCIS (Netherlands)

    Pereira, CF; Boven, LA; Middel, J; Verhoef, J; Nottet, HSLM

    2000-01-01

    Human immunodeficiency virus type-1 (HIV-1)-associated dementia (HAD) is a neurodegenerative disease characterized by HIV infection and replication in brain tissue. HIV-1-infected monocytes overexpress inflammatory molecules that facilitate their entry into the brain. Prostanoids are lipid mediators

  6. Comparative expression profile of miRNA and mRNA in primary peripheral blood mononuclear cells infected with human immunodeficiency virus (HIV-1.

    Directory of Open Access Journals (Sweden)

    Ankit Gupta

    Full Text Available Host cells respond to exogenous infectious agents such as viruses, including HIV-1. Studies have evaluated the changes associated with virus infection at the transcriptional and translational levels of the cellular genes involved in specific pathways. While this approach is useful, in our view it provides only a partial view of genome-wide changes. Recently, technological advances in the expression profiling at the microRNA (miRNA and mRNA levels have made it possible to evaluate the changes in the components of multiple pathways. To understand the role of miRNA and its interplay with host cellular gene expression (mRNA during HIV-1 infection, we performed a comparative global miRNA and mRNA microarray using human PBMCs infected with HIV-1. The PBMCs were derived from multiple donors and were infected with virus generated from the molecular clone pNL4-3. The results showed that HIV-1 infection led to altered regulation of 21 miRNAs and 444 mRNA more than 2-fold, with a statistical significance of p<0.05. Furthermore, the differentially regulated miRNA and mRNA were shown to be associated with host cellular pathways involved in cell cycle/proliferation, apoptosis, T-cell signaling, and immune activation. We also observed a number of inverse correlations of miRNA and mRNA expression in infected PBMCs, further confirming the interrelationship between miRNA and mRNA regulation during HIV-1 infection. These results for the first time provide evidence that the miRNA profile could be an early indicator of host cellular dysfunction induced by HIV-1.

  7. Expression of HIV-1 antigens in plants as potential subunit vaccines

    CSIR Research Space (South Africa)

    Meyers, A

    2008-06-23

    Full Text Available highest in transient and transgenic expression of p24 and p17/p24. The transiently-expressed p17/p24 was not immunogenic in mice as a homologous vaccine, but it significantly boosted a humoral and T cell immune response primed by a gag DNA vaccine, pTHGagC...

  8. Differential expression of CD96 surface molecule represents CD8⁺ T cells with dissimilar effector function during HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Emily M Eriksson

    Full Text Available During HIV-1 infection, immune dysregulation and aberrant lymphocyte functions are well-established characteristics. Cell surface molecules are important for immunological functions and changes in expression can affect lymphocyte effector functions, thereby contributing to pathogenesis and disease progression. In this study we have focused on CD96, a member of the IgG superfamily receptors that have generated increasing recent interest due to their adhesive and co-stimulatory functions in addition to immunoregulatory capacity. CD96 is expressed by both T and NK cells. Although the function of CD96 is not completely elucidated, it has been shown to have adhesive functions and enhance cytotoxicity. Interestingly, CD96 may also have inhibitory functions due to its immunoreceptor tyrosine-based inhibitory motif (ITIM. The clinical significance of CD96 is still comparatively limited although it has been associated with chronic Hepatitis B infection and disease progression. CD96 has not previously been studied in the context of HIV-1 infection, but due to its potential importance in immune regulation and relevance to chronic disease, we examined CD96 expression in relation to HIV-1 pathogenesis. In a cross-sectional analysis, we investigated the CD8(+ T cell expression of CD96 in cohorts of untreated HIV-1 infected adults with high viral loads (non-controllers and low viral loads ("elite" controllers. We demonstrated that elite controllers have significantly higher CD96 mean fluorescence intensity on CD8(+ T cells compared to HIV-1 non-controllers and CD96 expression was positively associated with CD4(+ T cell counts. Functional assessment showed that CD8(+ T cells lacking CD96 expression represented a population that produced both perforin and IFN-γ following stimulation. Furthermore, CD96 expression on CD8(+ T cells was decreased in presence of lipopolysaccharide in vitro. Overall, these findings indicate that down-regulation of CD96 is an

  9. Cardiac Dysfunction in HIV-1 Transgenic Mouse: Role of Stress and BAG3.

    Science.gov (United States)

    Cheung, Joseph Y; Gordon, Jennifer; Wang, JuFang; Song, Jianliang; Zhang, Xue-Qian; Tilley, Douglas G; Gao, Erhe; Koch, Walter J; Rabinowitz, Joseph; Klotman, Paul E; Khalili, Kamel; Feldman, Arthur M

    2015-08-01

    Since highly active antiretroviral therapy improved long-term survival of acquired immunodeficiency syndrome (AIDS) patients, AIDS cardiomyopathy has become an increasingly relevant clinical problem. We used human immunodeficiency virus (HIV)-1 transgenic (Tg26) mouse to explore molecular mechanisms of AIDS cardiomyopathy. Tg26 mice had significantly lower left ventricular (LV) mass and smaller end-diastolic and end-systolic LV volumes. Under basal conditions, cardiac contractility and relaxation and single myocyte contraction dynamics were not different between wild-type (WT) and Tg26 mice. Ten days after open heart surgery, contractility and relaxation remained significantly depressed in Tg26 hearts, suggesting that Tg26 mice did not tolerate surgical stress well. To simulate heart failure in which expression of Bcl2-associated athanogene 3 (BAG3) is reduced, we down-regulated BAG3 by small hairpin ribonucleic acid in WT and Tg26 hearts. BAG3 down-regulation significantly reduced contractility in Tg26 hearts. BAG3 overexpression rescued contractile abnormalities in myocytes expressing the HIV-1 protein Tat. We conclude: (i) Tg26 mice exhibit normal contractile function at baseline; (ii) Tg26 mice do not tolerate surgical stress well; (iii) BAG3 down-regulation exacerbated cardiac dysfunction in Tg26 mice; (iv) BAG3 overexpression rescued contractile abnormalities in myocytes expressing HIV-1 protein Tat; and (v) BAG3 may occupy a role in pathogenesis of AIDS cardiomyopathy. © 2015 Wiley Periodicals, Inc.

  10. Japanese encephalitis virus-based replicon RNAs/particles as an expression system for HIV-1 Pr55 Gag that is capable of producing virus-like particles.

    Science.gov (United States)

    Yun, Sang-Im; Song, Byung-Hak; Koo, Yongbum; Jeon, Iksoo; Byun, Sung June; Park, Jong-Hyeon; Joo, Yi-Seok; Kim, Seok-Yong; Lee, Young-Min

    2009-09-01

    Ectopic expression of the structural protein Pr55(Gag) of HIV-1 has been limited by the presence of inhibitory sequences in the gag coding region that must normally be counteracted by HIV-1 Rev and RRE. Here, we describe a cytoplasmic RNA replicon based on the RNA genome of Japanese encephalitis virus (JEV) that is capable of expressing HIV-1 gag without requiring Rev/RRE. This replicon system was constructed by deleting all three JEV structural protein-coding regions (C, prM, and E) from the 5'-proximal region of the genome and simultaneously inserting an HIV-1 gag expression cassette driven by the internal ribosome entry site of encephalomyocarditis virus into the 3'-proximal noncoding region of the genome. Transfection of this JEV replicon RNA led to expression of Pr55(Gag) in the absence of Rev/RRE in the cytoplasm of hamster BHK-21, human HeLa, and mouse NIH/3T3 cells. Production of the Pr55(Gag) derived from this JEV replicon RNA appeared to be increased by approximately 3-fold when compared to that based on an alphavirus replicon RNA. Biochemical and morphological analyses demonstrated that the Pr55(Gag) proteins were released into the culture medium in the form of virus-like particles. We also observed that the JEV replicon RNAs expressing the Pr55(Gag) could be encapsidated into single-round infectious JEV replicon particles when transfected into a stable packaging cell line that provided the three JEV structural proteins in trans. This ectopic expression of the HIV-1 Pr55(Gag) by JEV-based replicon RNAs/particles in diverse cell types may represent a useful molecular platform for various biological applications in medicine and industry.

  11. CDK2 Regulates HIV-1 Transcription by Phosphorylation of CDK9 on Serine 90

    Directory of Open Access Journals (Sweden)

    Breuer Denitra

    2012-11-01

    Full Text Available Abstract Background HIV-1 transcription is activated by the viral Tat protein that recruits host positive transcription elongation factor-b (P-TEFb containing CDK9/cyclin T1 to the HIV-1 promoter. P-TEFb in the cells exists as a lower molecular weight CDK9/cyclin T1 dimer and a high molecular weight complex of 7SK RNA, CDK9/cyclin T1, HEXIM1 dimer and several additional proteins. Our previous studies implicated CDK2 in HIV-1 transcription regulation. We also found that inhibition of CDK2 by iron chelators leads to the inhibition of CDK9 activity, suggesting a functional link between CDK2 and CDK9. Here, we investigate whether CDK2 phosphorylates CDK9 and regulates its activity. Results The siRNA-mediated knockdown of CDK2 inhibited CDK9 kinase activity and reduced CDK9 phosphorylation. Stable shRNA-mediated CDK2 knockdown inhibited HIV-1 transcription, but also increased the overall level of 7SK RNA. CDK9 contains a motif (90SPYNR94 that is consensus CDK2 phosphorylation site. CDK9 was phosphorylated on Ser90 by CDK2 in vitro. In cultured cells, CDK9 phosphorylation was reduced when Ser90 was mutated to an Ala. Phosphorylation of CDK9 on Ser90 was also detected with phospho-specific antibodies and it was reduced after the knockdown of CDK2. CDK9 expression decreased in the large complex for the CDK9-S90A mutant and was correlated with a reduced activity and an inhibition of HIV-1 transcription. In contrast, the CDK9-S90D mutant showed a slight decrease in CDK9 expression in both the large and small complexes but induced Tat-dependent HIV-1 transcription. Molecular modeling showed that Ser 90 of CDK9 is located on a flexible loop exposed to solvent, suggesting its availability for phosphorylation. Conclusion Our data indicate that CDK2 phosphorylates CDK9 on Ser 90 and thereby contributes to HIV-1 transcription. The phosphorylation of Ser90 by CDK2 represents a novel mechanism of HIV-1 regulated transcription and provides a new strategy for

  12. B-oligomer of pertussis toxin inhibits HIV-1 LTR-driven transcription through suppression of NF-kappaB p65 subunit activity.

    Science.gov (United States)

    Iordanskiy, Sergey; Iordanskaya, Tatyana; Quivy, Vincent; Van Lint, Carine; Bukrinsky, Michael

    2002-10-10

    The binding subunit of pertussis toxin (PTX-B) has been shown recently to inhibit the entry and postentry events in HIV-1 replication in primary T lymphocytes and monocyte-derived macrophages. While the effect of PTX-B on HIV-1 entry was shown to involve CCR5 desensitization, the mechanism of postentry inhibition remained unclear. In T lymphocytes, PTX-B affected transcription or stability of Tat-stimulated HIV-1 mRNAs. In this study, we sought to identify the mechanism of postentry inhibition of HIV-1 replication by PTX-B in U-937 promonocytic cells. We demonstrate that in these cells PTX-B inhibits expression of luciferase reporter gene controlled by the HIV-1 LTR promoter. This effect is Tat-independent and is not restricted to the HIV-1 LTR promoter. Instead, PTX-B activity is mediated through suppression of the cellular transcription factor, NF-kappaB. PTX-B inhibits phosphorylation and nuclear translocation of the p65 subunit of NF-kappaB. This effect is independent of the cytoplasmic NF-kappaB inhibitor, IkappaBalpha, as PTX-B stimulates phosphorylation and subsequent degradation of this protein. The suppressive activity of PTX-B on NF-kappaB p65 phosphorylation and nuclear translocation is delayed, suggesting that PTX-B signaling might initiate synthesis and cytoplasmic accumulation of a p65 phosphorylation inhibitor.

  13. Stable EGFP Gene Expression in C6 Glioma Cell Line after Transduction with HIV-1-based Lentiviral Vector

    Institute of Scientific and Technical Information of China (English)

    JIN Gui-shan; LIU Fu-sheng; CHAI Qi; WANG Jian-jao; LI Jun-hua

    2008-01-01

    Objective:To establish a stable C6/EGFP glioma cell line for studies on glioma. Methods:The C6 glioma cell line was transfected with the human immunodeficiency virus type Ⅰ(HIV-1)based lentivirus vector containing two enhancer-promoters CMV and EF1α.Enhanced green fluorescent protein(EGFP)-positive C6 cells were sorted out by fluorescence-activated cell sort.Expression of EGFP was observed by fluorescent microscopy.EGFP gene in C6 genome was assessed by Polymerase chain reaction(PCR)and DNA sequencing.Original and transfected cells were compared biologically and cytomorphologically. Results:Lentivirus vector transfection produced up to 40% EGFP-positive cells.After fluorescence-activated cell sort selection,a pure cell line C6/EGFP was established.PCR and DNA sequencing revealed integration of EGFP gene in C6 cell genome.Analysis of cell characteristics revealed no difference between transfected and original cells. Conclusion:A C6/EGFP cell line expressing EGFP as a marker is established,in which the EGFP gene is integrated into the genome.This cell line can be served as a promising tool for further basic research and gene therapy studies.

  14. Functional analysis of the Tat trans activator of human immunodeficiency virus type 2.

    OpenAIRE

    Fenrick, R; Malim, M H; Hauber, J; Le, S.Y.; Maizel, J; Cullen, B R

    1989-01-01

    The trans-activator (Tat) proteins of the related but distinct type 1 and type 2 human immunodeficiency viruses (HIV-1 and HIV-2) display incomplete functional reciprocity. One possible explanation of this observation, suggested by computer analysis of potential RNA secondary structures within the viral trans-activation response (TAR) elements, is that HIV-2 Tat requires the presentation of two viral RNA stem-loop sequences for full activity whereas HIV-1 Tat is maximally active upon presenta...

  15. Engineering and Validation of a Vector for Concomitant Expression of Rare Transfer RNA (tRNA and HIV-1 nef Genes in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Siti Aisyah Mualif

    Full Text Available Relative ease in handling and manipulation of Escherichia coli strains make them primary candidate to express proteins heterologously. Overexpression of heterologous genes that contain codons infrequently used by E. coli is related with difficulties such as mRNA instability, early termination of transcription and/or translation, deletions and/or misincorporation, and cell growth inhibition. These codon bias -associated problems are addressed by co-expressing ColE1-compatible, rare tRNA expressing helper plasmids. However, this approach has inadequacies, which we have addressed by engineering an expression vector that concomitantly expresses the heterologous protein of interest, and rare tRNA genes in E. coli. The expression vector contains three (argU, ileY, leuW rare tRNA genes and a useful multiple cloning site for easy in-frame cloning. To maintain the overall size of the parental plasmid vector, the rare tRNA genes replaced the non-essential DNA segments in the vector. The cloned gene is expressed under the control of T7 promoter and resulting recombinant protein has a C-terminal 6His tag for IMAC-mediated purification. We have evaluated the usefulness of this expression vector by expressing three HIV-1 genes namely HIV-1 p27 (nef, HIV-1 p24 (ca, and HIV-1 vif in NiCo21(DE3 E.coli and demonstrated the advantages of using expression vector that concomitantly expresses rare tRNA and heterologous genes.

  16. Monitoring CD27 expression to evaluate Mycobacterium tuberculosis activity in HIV-1 infected individuals in vivo.

    Science.gov (United States)

    Schuetz, Alexandra; Haule, Antelmo; Reither, Klaus; Ngwenyama, Njabulo; Rachow, Andrea; Meyerhans, Andreas; Maboko, Leonard; Koup, Richard A; Hoelscher, Michael; Geldmacher, Christof

    2011-01-01

    The level of bacterial activity is only poorly defined during asymptomatic Mycobacterium tuberculosis (MTB) infection. The objective was to study the capacity of a new biomarker, the expression of the T cell maturation marker CD27 on MTB-specific CD4 T cells, to identify active tuberculosis (TB) disease in subjects from a MTB and HIV endemic region. The frequency and CD27 expression of circulating MTB-specific CD4 T cells was determined in 96 study participants after stimulation with purified protein derivative (PPD) using intracellular cytokine staining for IFNgamma (IFNγ). Subjects were then stratified by their TB and HIV status. Within PPD responders, a CD27(-) phenotype was associated with active TB in HIV(-) (p = 0.0003) and HIV(+) (p = 0.057) subjects, respectively. In addition, loss of CD27 expression preceded development of active TB in one HIV seroconverter. Interestingly, in contrast to HIV(-) subjects, MTB-specific CD4 T cell populations from HIV(+) TB-asymptomatic subjects were often dominated by CD27(-) cells. These data indicate that down-regulation of CD27 on MTB-specific CD4 T cell could be used as a biomarker of active TB, potentially preceding clinical TB disease. Furthermore, these data are consistent with the hypothesis that late, chronic HIV infection is frequently associated with increased mycobacterial activity in vivo. The analysis of T cell maturation and activation markers might thus be a useful tool to monitor TB disease progression.

  17. Monitoring CD27 expression to evaluate Mycobacterium tuberculosis activity in HIV-1 infected individuals in vivo.

    Directory of Open Access Journals (Sweden)

    Alexandra Schuetz

    Full Text Available The level of bacterial activity is only poorly defined during asymptomatic Mycobacterium tuberculosis (MTB infection. The objective was to study the capacity of a new biomarker, the expression of the T cell maturation marker CD27 on MTB-specific CD4 T cells, to identify active tuberculosis (TB disease in subjects from a MTB and HIV endemic region. The frequency and CD27 expression of circulating MTB-specific CD4 T cells was determined in 96 study participants after stimulation with purified protein derivative (PPD using intracellular cytokine staining for IFNgamma (IFNγ. Subjects were then stratified by their TB and HIV status. Within PPD responders, a CD27(- phenotype was associated with active TB in HIV(- (p = 0.0003 and HIV(+ (p = 0.057 subjects, respectively. In addition, loss of CD27 expression preceded development of active TB in one HIV seroconverter. Interestingly, in contrast to HIV(- subjects, MTB-specific CD4 T cell populations from HIV(+ TB-asymptomatic subjects were often dominated by CD27(- cells. These data indicate that down-regulation of CD27 on MTB-specific CD4 T cell could be used as a biomarker of active TB, potentially preceding clinical TB disease. Furthermore, these data are consistent with the hypothesis that late, chronic HIV infection is frequently associated with increased mycobacterial activity in vivo. The analysis of T cell maturation and activation markers might thus be a useful tool to monitor TB disease progression.

  18. Expression of TAT recombinant Oct4, Sox2, Lin28, and Nanog proteins from baculovirus-infected Sf9 insect cells.

    Science.gov (United States)

    Pan, Chuanying; Jia, Wenchao; Lu, Baisong; Bishop, Colin E

    2015-02-10

    Somatic cell reprogramming has generated enormous interest, following the first report of generation of induced pluripotent stem cells (iPSCs) from mouse fibroblasts, but the integration of viral transgenes into the genome is unlikely to be accepted. Given these safety considerations, a method for virus-free transient gene expression from suspension-adapted Sf9 insect cells was developed. Here, we expressed transactivator of transcription (TAT)-fused proteins, Sox2, Oct4, Lin28, and Nanog in Sf9 cells using the baculovirus expression vector system (BEVS). The molecular weights of the TAT-Sox2, TAT-Oct4, TAT-Lin28, and TAT-Nanog fusion proteins were 36kD, 40kD, 24kD, and 36kD, respectively. Further investigation indicated that most of the recombinant proteins remained in the nuclei of the Sf9 insect cells and were therefore unavailable for purification and cellular reprogramming. Once this problem has been solved, it seems likely that protein expressed from baculovirus-infected Sf9 insect cells will be the method of choice for cellular reprogramming.

  19. Multivalent dendrimeric compounds containing carbohydrates expressed on immune cells inhibit infection by primary isolates of HIV-1

    Science.gov (United States)

    Borges, Andrew Rosa; Wieczorek, Lindsay; Johnson, Benitra; Benesi, Alan J.; Brown, Bruce K.; Kensinger, Richard D.; Krebs, Fred C.; Wigdahl, Brian; Blumenthal, Robert; Puri, Anu; McCutchan, Francine E.; Birx, Deborah L.; Polonis, Victoria R.; Schengrund, Cara-Lynne

    2010-01-01

    Specific glycosphingolipids (GSL), found on the surface of target immune cells, are recognized as alternate cell surface receptors by the human immunodeficiency virus type 1 (HIV-1) external envelope glycoprotein. In this study, the globotriose and 3’-sialyllactose carbohydrate head groups found on two GSL were covalently attached to a dendrimer core to produce two types of unique multivalent carbohydrates (MVC). These MVC inhibited HIV-1 infection of T cell lines and primary peripheral blood mononuclear cells (PBMC) by T cell line-adapted viruses or primary isolates, with IC50s ranging from 0.1 – 7.4 µg/ml. Inhibition of Env-mediated membrane fusion by MVC was also observed using a dye-transfer assay. These carbohydrate compounds warrant further investigation as a potential new class of HIV-1 entry inhibitors. The data presented also shed light on the role of carbohydrate moieties in HIV-1 virus-host cell interactions. PMID:20880566

  20. Effects of root, shoot, leaf and seed extracts of sevenArtemisia species on HIV-1 replication and CD4 expression

    Institute of Scientific and Technical Information of China (English)

    Hassan Mohabatkar; Mandana Behbahani; Mohammad Reza Rahimi Nejad

    2015-01-01

    Objective:To investigate the effects of flower, leaf, shoot and root extracts of sevenArtemisia species on peripheral blood mononuclear cells (PBMCs) toxicity andHIV-1 replication. Methods:The studiedArtemisia species wereArtemisia absinthium, Artemisia khorasanica, Artemisia deserti, Artemisia fragrans, Artemisia aucheri, Artemisia sieberi andArtemisia vulgaris. The activity of these plant extracts onHIV-1 replication andCD4 expression was performed byHIV-1 p24 antigen kit and flow cytometry respectively. Results: The results demonstrated that flower extracts of all species increasedPBMCs number more than shoot, leaf and root extracts. However, the frequency ofCD4 expression inPBMC was not increased in the presence of all flower extracts. The flower extracts of all species had inhibitory effect onHIV-1 replication. Conclusions:In conclusion, the results demonstrated that flower extracts ofArtemisia species are good candidates for further studies as anticancer agents.

  1. Novel PI3K/Akt inhibitors screened by the cytoprotective function of human immunodeficiency virus type 1 Tat.

    Directory of Open Access Journals (Sweden)

    Yuri Kim

    Full Text Available The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors.

  2. Novel PI3K/Akt Inhibitors Screened by the Cytoprotective Function of Human Immunodeficiency Virus Type 1 Tat

    Science.gov (United States)

    Kim, Dong-Hyun; Kim, Baek

    2011-01-01

    The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors. PMID:21765914

  3. Synergistic Activation of Latent HIV-1 Expression by Novel Histone Deacetylase Inhibitors and Bryostatin-1.

    Science.gov (United States)

    Martínez-Bonet, Marta; Clemente, Maria Isabel; Serramía, Maria Jesús; Muñoz, Eduardo; Moreno, Santiago; Muñoz-Fernández, Maria Ángeles

    2015-11-13

    Viral reactivation from latently infected cells has become a promising therapeutic approach to eradicate HIV. Due to the complexity of the viral latency, combinations of efficient and available drugs targeting different pathways of latency are needed. In this work, we evaluated the effect of various combinations of bryostatin-1 (BRY) and novel histone deacetylase inhibitors (HDACIs) on HIV-reactivation and on cellular phenotype. The lymphocyte (J89GFP) or monocyte/macrophage (THP89GFP) latently infected cell lines were treated with BRY, panobinostat (PNB) and romidepsin (RMD) either alone or in combination. Thus, the effect on the viral reactivation was evaluated. We calculated the combination index for each drug combination; the BRY/HDACIs showed a synergistic HIV-reactivation profile in the majority of the combinations tested, whereas non-synergistic effects were observed when PNB was mixed with RMD. Indeed, the 75% effective concentrations of BRY, PNB and RMD were reduced in these combinations. Moreover, primary CD4 T cells treated with such drug combinations presented similar activation and proliferation profiles in comparison with single drug treated cells. Summing up, combinations between BRY, PNB and/or RMD presented a synergistic profile by inducing virus expression in HIV-latently infected cells, rendering these combinations an attractive novel and safe option for future clinical trials.

  4. High Expression of Antiviral and Vitamin D Pathway Genes Are a Natural Characteristic of a Small Cohort of HIV-1-Exposed Seronegative Individuals

    Science.gov (United States)

    Aguilar-Jimenez, Wbeimar; Saulle, Irma; Trabattoni, Daria; Vichi, Francesca; Lo Caputo, Sergio; Mazzotta, Francesco; Rugeles, Maria T.; Clerici, Mario; Biasin, Mara

    2017-01-01

    Natural resistance to HIV-1 infection is influenced by genetics, viral-exposure, and endogenous immunomodulators such as vitamin D (VitD), being a multifactorial phenomenon that characterizes HIV-1-exposed seronegative individuals (HESNs). We compared mRNA expression of 10 antivirals, 5 immunoregulators, and 3 VitD pathway genes by qRT-PCR in cells of a small cohort of 11 HESNs, 16 healthy-controls (HCs), and 11 seropositives (SPs) at baseline, in response to calcidiol (VitD precursor) and/or aldithriol-2-(AT2)-inactivated HIV-1. In addition, the expression of TIM-3 on T and NK cells of six HCs after calcidiol and calcitriol (active VitD) treatments was evaluated by flow cytometry. Calcidiol increased the mRNA expression of HAVCR2 (TIM-3; Th1-cells inhibitor) in HCs and HESNs. AT2-HIV-1 increased the mRNA expression of the activating VitD enzyme CYP27B1, of the endogenous antiviral proteins MX2, TRIM22, APOBEC3G, and of immunoregulators ERAP2 and HAVCR2, but reduced the mRNA expression of VitD receptor (VDR) and antiviral peptides PI3 and CAMP in all groups. Remarkably, higher mRNA levels of VDR, CYP27B1, PI3, CAMP, SLPI, and of ERAP2 were found in HESNs compared to HCs either at baseline or after stimuli. Furthermore, calcitriol increases the percentage of CD4+ T cells expressing TIM-3 protein compared to EtOH controls. These results suggest that high mRNA expression of antiviral and VitD pathway genes could be genetically determined in HESNs more than viral-induced at least in peripheral blood mononuclear cells. Moreover, the virus could potentiate bio-activation and use of VitD, maintaining the homeostasis of the immune system. Interestingly, VitD-induced TIM-3 on T cells, a T cell inhibitory and anti-HIV-1 molecule, requires further studies to analyze the functional outcomes during HIV-1 infection. PMID:28243241

  5. Programmed death-1 expression on HIV-1-specific CD8+ T cells is shaped by epitope specificity, T-cell receptor clonotype usage and antigen load

    DEFF Research Database (Denmark)

    Kløverpris, Henrik N; McGregor, Reuben; McLaren, James E

    2014-01-01

    OBJECTIVES: Although CD8+ T cells play a critical role in the control of HIV-1 infection,their antiviral efficacy can be limited by antigenic variation and immune exhaustion.The latter phenomenon is characterized by the upregulation of multiple inhibitory receptors, such as programmed death-1 (PD-1......), CD244 and lymphocyte activation gene-3 (LAG-3), which modulate the functional capabilities of CD8+ T cells. DESIGN AND METHODS: Here, we used an array of different human leukocyte antigen(HLA)-B*15:03 and HLA-B*42:01 tetramers to characterize inhibitory receptor expression as a function...... by effector memory CD8+ T cells. CONCLUSION: Collectively, these data suggest that PD-1 expression on HIV-1-specific CD8+ T cells tracks antigen load at the level of epitope specificity and TCR clonotype usage. These findings are important because they provide evidence that PD-1 expression levels...

  6. Gene expression analysis of a panel of cell lines that differentially restrict HIV-1 CA mutants infection in a cyclophilin a-dependent manner.

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    Vaibhav B Shah

    Full Text Available HIV-1 replication is dependent on binding of the viral capsid to the host protein cyclophilin A (CypA. Interference with cyclophilin A binding, either by mutations in the HIV-1 capsid protein (CA or by the drug cyclosporine A (CsA, inhibits HIV-1 replication in cell culture. Resistance to CsA is conferred by A92E or G94D substitutions in CA. The mutant viruses are also dependent on CsA for their replication. Interestingly, infection of some cell lines by these mutants is enhanced by CsA, while infection of others is not affected by the drug. The cells are thus termed nonpermissive and permissive, respectively, for infection by CsA-dependent mutants. The mechanistic basis for the cell type dependence is not well understood, but has been hypothesized to result from a dominant-acting host factor that blocks HIV-1 infection by a mechanism that requires CypA binding to the viral capsid. In an effort to identify a CypA-dependent host restriction factor, we adopted a strategy involving comparative gene expression analysis in three permissive and three non-permissive cell types. We ranked the genes based on their relative overexpression in non-permissive cell types compared to the permissive cell types. Based on specific selection criteria, 26 candidate genes were selected and targeted using siRNA in nonpermissive (HeLa cells. Depletion of none of the selected candidate genes led to the reversal of CsA-dependent phenotype of the A92E mutant. Our data suggest that none of the 26 genes tested is responsible for the dependence of the A92E mutant on CsA. Our study provides gene expression data that may be useful for future efforts to identify the putative CypA-dependent HIV-1 restriction factor and in studies of other cell-specific phenotypes.

  7. A mouse model based on replication-competent Tiantan vaccinia expressing luciferase/HIV-1 Gag fusion protein for the evaluation of protective efficacy of HIV vaccine

    Institute of Scientific and Technical Information of China (English)

    HUANG Yang; QIU Chao; LIU Lian-xing; FENG Yan-meng; ZHU Ting; XU Jian-qing

    2009-01-01

    Background Developing an effective vaccine against human immunodeficiency virus type 1 (HIV-1) remains a grand challenge after more than two decades of intensive effort. It is partially due to the lack of suitable animal models for screening and prioritizing vaccine candidates. In this study, we aim to develop a mice model to test HIV-1 vaccine efficacy. Methods We constructed a recombinant vaccinia expressing firefly luciferase and HIV-1 Gag fusion protein based on Tiantan strain, an attenuated but replication-competent poxvirus (rTTV-lucgag). By quantifying the luciferase activity as its read out, we defined the biodistribution of Tiantan strain poxvirus in mice inoculated intraperitoneally and attempted to apply this model to evaluate the HIV-1 vaccine efficacy. Results Our data demonstrated that the rTTV-lucgag was able to express high level of luciferase (≤106 relative luciferase units (RLU)/mg protein) and HIV-1 Gag (>3 folds increase comparing to the control). After intraperitoneal inoculation, this virus had dominant replication in the ovary, uterus, and cervix of mice and the luciferase activities in those organs are significantly correlated with viral titers (r2=0.71, P <0.01). Pre-immunization with an HIV gag DNA vaccine reduced the luciferase activity in ovary from (6006+3141) RLU/mg protein in control group to (1538±463) RLU/mg protein in vaccine group (P=0.1969). Conclusions The luciferase activity in ovary could represent viral replication in vivo;, this rTTV-lucgag/mice model may be suitable to assess the protective efficacy of cytotoxic T-cell responses to HIV Gag with less tedious work and high through-put.

  8. Expression of Werner and Bloom syndrome genes is differentially regulated by in vitro HIV-1 infection of peripheral blood mononuclear cells.

    Science.gov (United States)

    Bordi, L; Amendola, A; Ciccosanti, F; Abbate, I; Camilloni, G; Capobianchi, M R

    2004-11-01

    In HIV infection, continuous immune activation leads to accelerated ageing of the adaptive immune system, similar to that observed in elderly people. We investigated the expression of WRN and BLM (genes involved in disorders characterized by premature ageing, genomic instability and cancer predisposition) in peripheral blood mononuclear cells (PBMC) activated in vitro with phytohaemagglutinin (PHA) and infected with different HIV-1 strains. The steady state levels of mRNA were analysed by reverse transcription-polymerase chain reaction (RT-PCR), and protein expression was assayed using immunocytochemistry and Western blot techniques. In uninfected PBMC, PHA stimulation induced an increase in BLM mRNA and protein expression, while WRN expression remained virtually unchanged. When PBMC were infected in vitro with a lymphotropic HIV-1 strain, the level of BLM mRNA showed a peak at 24 h of infection, followed by a decline to uninfected culture levels. A similar result failed to be seen using an R5-tropic HIV-1 strain. In accordance with mRNA expression, in HIV-infected cultures PBMC were stained more frequently and more intensely by a BLM-specific antibody as compared to uninfected cultures, staining peaking at 24. Conversely, WRN expression was not modulated by HIV-1. The proportion of cells showing BLM up-regulation, established by immunocytochemical staining, was much greater than the proportion of productively infected PBMC, as established by proviral DNA measurement. This result indicates that BLM up-regulation is probably a result of an indirect bystander cell effect. Activation of the BLM gene in infected PBMC suggests that premature ageing could be a further immunopathogenetic mechanism involved in HIV-induced immunodeficiency, and points to a possible new candidate target for innovative therapeutic intervention.

  9. Heterologous prime-boost-boost immunisation of Chinese cynomolgus macaques using DNA and recombinant poxvirus vectors expressing HIV-1 virus-like particles

    Directory of Open Access Journals (Sweden)

    Anson Donald S

    2011-09-01

    Full Text Available Abstract Background There is renewed interest in the development of poxvirus vector-based HIV vaccines due to the protective effect observed with repeated recombinant canarypox priming with gp120 boosting in the recent Thai placebo-controlled trial. This study sought to investigate whether a heterologous prime-boost-boost vaccine regimen in Chinese cynomolgus macaques with a DNA vaccine and recombinant poxviral vectors expressing HIV virus-like particles bearing envelopes derived from the most prevalent clades circulating in sub-Saharan Africa, focused the antibody response to shared neutralising epitopes. Methods Three Chinese cynomolgus macaques were immunised via intramuscular injections using a regimen composed of a prime with two DNA vaccines expressing clade A Env/clade B Gag followed by boosting with recombinant fowlpox virus expressing HIV-1 clade D Gag, Env and cholera toxin B subunit followed by the final boost with recombinant modified vaccinia virus Ankara expressing HIV-1 clade C Env, Gag and human complement protein C3d. We measured the macaque serum antibody responses by ELISA, enumerated T cell responses by IFN-γ ELISpot and assessed seroneutralisation of HIV-1 using the TZM-bl β-galactosidase assay with primary isolates of HIV-1. Results This study shows that large and complex synthetic DNA sequences can be successfully cloned in a single step into two poxvirus vectors: MVA and FPV and the recombinant poxviruses could be grown to high titres. The vaccine candidates showed appropriate expression of recombinant proteins with the formation of authentic HIV virus-like particles seen on transmission electron microscopy. In addition the b12 epitope was shown to be held in common by the vaccine candidates using confocal immunofluorescent microscopy. The vaccine candidates were safely administered to Chinese cynomolgus macaques which elicited modest T cell responses at the end of the study but only one out of the three macaques

  10. Bryostatin activates HIV-1 latent expression in human astrocytes through a PKC and NF-ĸB-dependent mechanism.

    Science.gov (United States)

    Díaz, Laura; Martínez-Bonet, Marta; Sánchez, Javier; Fernández-Pineda, Alejandra; Jiménez, José Luis; Muñoz, Eduardo; Moreno, Santiago; Álvarez, Susana; Muñoz-Fernández, Ma Ángeles

    2015-07-22

    Multiple studies have shown that HIV-1 patients may develop virus reservoirs that impede eradication; these reservoirs include the central nervous system (CNS). Despite an undetectable viral load in patients treated with potent antiretrovirals, current therapy is unable to purge the virus from these latent reservoirs. To broaden the inhibitory range and effectiveness of current antiretrovirals, the potential of bryostatin was investigated as a latent HIV-1 activator. We used primary astrocytes, NHA cells, and astrocytoma cells U-87. Infected cells with HIV-1(NL4.3) were treated with bryostatin alone or in combination with different inhibitors. HIV-1 production was quantified by using ELISA. Transcriptional activity was measured using luciferase reporter gene assays by using lipofectin. We performed cotransfection experiments of the LTR promoter with the active NF-κB member p65/relA. To confirm the NF-κB role, Western blot and confocal microscopy were performed. Bryostatin reactivates latent viral infection in the NHA and U87 cells via activation of protein kinase C (PKC)-alpha and -delta, because the PKC inhibitors rottlerin and GF109203X abrogated the bryostatin effect. No alteration in cell proliferation was found. Moreover, bryostatin strongly stimulated LTR transcription by activating the transcription factor NF-κB. Bryostatin could be a beneficial adjunct to the treatment of HIV-1 brain infection.

  11. Inhibition of HIV Replication by Cyclic and Hairpin PNAs Targeting the HIV-1 TAR RNA Loop

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    Gregory Upert

    2012-01-01

    Full Text Available Human immunodeficiency virus-1 (HIV-1 replication and gene expression entails specific interaction of the viral protein Tat with its transactivation responsive element (TAR, to form a highly stable stem-bulge-loop structure. Previously, we described triphenylphosphonium (TPP cation-based vectors that efficiently deliver nucleotide analogs (PNAs into the cytoplasm of cells. In particular, we showed that the TPP conjugate of a linear 16-mer PNA targeting the apical stem-loop region of TAR impedes Tat-mediated transactivation of the HIV-1 LTR in vitro and also in cell culture systems. In this communication, we conjugated TPP to cyclic and hairpin PNAs targeting the loop region of HIV-1 TAR and evaluated their antiviral efficacy in a cell culture system. We found that TPP-cyclic PNAs containing only 8 residues, showed higher antiviral potency compared to hairpin PNAs of 12 or 16 residues. We further noted that the TPP-conjugates of the 8-mer cyclic PNA as well as the 16-mer linear PNA displayed similar antiviral efficacy. However, cyclic PNAs were shown to be highly specific to their target sequences. This communication emphasizes on the importance of small constrained cyclic PNAs over both linear and hairpin structures for targeting biologically relevant RNA hairpins.

  12. Dual Mechanisms of Translation Initiation of the Full-Length HIV-1 mRNA Contribute to Gag Synthesis

    Science.gov (United States)

    Rivero, Matias; Cohen, Éric A.; Lopez-Lastra, Marcelo; Mouland, Andrew J.

    2013-01-01

    The precursor group-specific antigen (pr55Gag) is central to HIV-1 assembly. Its expression alone is sufficient to assemble into virus-like particles. It also selects the genomic RNA for encapsidation and is involved in several important virus-host interactions for viral assembly and restriction, making its synthesis essential for aspects of viral replication. Here, we show that the initiation of translation of the HIV-1 genomic RNA is mediated through both a cap-dependent and an internal ribosome entry site (IRES)-mediated mechanisms. In support of this notion, pr55Gag synthesis was maintained at 70% when cap-dependent translation initiation was blocked by the expression of eIF4G- and PABP targeting viral proteases in two in vitro systems and in HIV-1-expressing cells directly infected with poliovirus. While our data reveal that IRES-dependent translation of the viral genomic RNA ensures pr55Gag expression, the synthesis of other HIV-1 proteins, including that of pr160Gag/Pol, Vpr and Tat is suppressed early during progressive poliovirus infection. The data presented herein implies that the unspliced HIV-1 genomic RNA utilizes both cap-dependent and IRES-dependent translation initiation to supply pr55Gag for virus assembly and production. PMID:23861855

  13. Dual mechanisms of translation initiation of the full-length HIV-1 mRNA contribute to gag synthesis.

    Directory of Open Access Journals (Sweden)

    Anne Monette

    Full Text Available The precursor group-specific antigen (pr55(Gag is central to HIV-1 assembly. Its expression alone is sufficient to assemble into virus-like particles. It also selects the genomic RNA for encapsidation and is involved in several important virus-host interactions for viral assembly and restriction, making its synthesis essential for aspects of viral replication. Here, we show that the initiation of translation of the HIV-1 genomic RNA is mediated through both a cap-dependent and an internal ribosome entry site (IRES-mediated mechanisms. In support of this notion, pr55(Gag synthesis was maintained at 70% when cap-dependent translation initiation was blocked by the expression of eIF4G- and PABP targeting viral proteases in two in vitro systems and in HIV-1-expressing cells directly infected with poliovirus. While our data reveal that IRES-dependent translation of the viral genomic RNA ensures pr55(Gag expression, the synthesis of other HIV-1 proteins, including that of pr160(Gag/Pol, Vpr and Tat is suppressed early during progressive poliovirus infection. The data presented herein implies that the unspliced HIV-1 genomic RNA utilizes both cap-dependent and IRES-dependent translation initiation to supply pr55(Gag for virus assembly and production.

  14. Relation of activation-induced deaminase (AID) expression with antibody response to A(H1N1)pdm09 vaccination in HIV-1 infected patients.

    Science.gov (United States)

    Cagigi, Alberto; Pensieroso, Simone; Ruffin, Nicolas; Sammicheli, Stefano; Thorstensson, Rigmor; Pan-Hammarström, Qiang; Hejdeman, Bo; Nilsson, Anna; Chiodi, Francesca

    2013-04-26

    The relevance of CD4+T-cells, viral load and age in the immunological response to influenza infection and vaccination in HIV-1 infected individuals has previously been pointed out. Our study aimed at assessing, in the setting of 2009 A(H1N1)pdm09 influenza vaccination, whether quantification of activation-induced deaminase (AID) expression in blood B-cells may provide additional indications for predicting antibody response to vaccination in HIV-1 infected patients with similar CD4+T-cell counts and age. Forty-seven healthy controls, 37 ART-treated and 17 treatment-naïve HIV-1 infected patients were enrolled in the study. Blood was collected prior to A(H1N1)pdm09 vaccination and at 1, 3 and 6 months after vaccination. Antibody titers to A(H1N1)pdm09 vaccine were measured by hemagglutination inhibition (HI) assay while the mRNA expression levels of AID were measured by quantitative real time PCR. Upon B-cell activation in vitro, AID increase correlated to antibody response to the A(H1N1)pdm09 vaccine at 1 month after vaccination in all individuals. In addition, the maximum expression levels of AID were significantly higher in those individuals who still carried protective levels of A(H1N1)pdm09 antibodies after 6 months from vaccination. No correlation was found between CD4+T-cell counts or age at vaccination or HIV-1 viral load and levels of A(H1N1)pdm09 antibodies. Assessing AID expression before vaccination may be an additional useful tool for defining a vaccination strategy in immune-compromised individuals at risk of immunization failure.

  15. Long-term passage of Vif-null HIV-1 in CD4(+) T cells expressing sub-lethal levels of APOBEC proteins fails to develop APOBEC resistance.

    Science.gov (United States)

    Miyagi, Eri; Kao, Sandra; Fumitaka, Miyoshi; Buckler-White, Alicia; Plishka, Ron; Strebel, Klaus

    2017-04-01

    APOBEC3G (A3G) is a cytidine deaminase with potent antiviral activity that is antagonized by Vif. A3G is expressed in a cell type-specific manner and some semi-permissive cells, including A3.01, express A3G but fail to block replication of Vif-null HIV-1. Here we explored the semi-permissive nature of A3.01 cells and found it to be defined exclusively by the levels of A3G. Indeed, minor changes in A3G levels rendered A3.01 cells either fully permissive or non-permissive for Vif-null HIV-1. Our data indicate that A3.01 cells express sub-lethal levels of catalytically active A3G that affects Vif-null HIV-1 at the proviral level but does not completely block virus replication due to purifying selection. Attempts to use the selective pressure exerted by such sub-lethal levels of A3G to select for APOBEC-resistant Vif-null virus capable of replicating in H9 cells failed despite passaging virus for five months, demonstrating that Vif is a critical viral accessory protein.

  16. HIV-1 Subtype C Mosaic Gag Expressed by BCG and MVA Elicits Persistent Effector T Cell Responses in a Prime-Boost Regimen in Mice.

    Directory of Open Access Journals (Sweden)

    Tsungai Ivai Jongwe

    Full Text Available Over 90% of HIV/AIDS positive individuals in sub-Saharan Africa are infected with highly heterogeneous HIV-1 subtype C (HIV-1C viruses. One of the best ways to reduce the burden of this disease is the development of an affordable and effective prophylactic vaccine. Mosaic immunogens are computationally designed to overcome the hurdle of HIV diversity by maximizing the expression of potential T cell epitopes. Mycobacterium bovis BCG ΔpanCD auxotroph and modified vaccinia Ankara (MVA vaccines expressing HIV-1C mosaic Gag (GagM were tested in a prime-boost regimen to demonstrate immunogenicity in a mouse study. The BCG-GagM vaccine was stable and persisted 11.5 weeks post vaccination in BALB/c mice. Priming with BCG-GagM and boosting with MVA-GagM elicited higher Gag-specific IFN-γ ELISPOT responses than the BCG-GagM only and MVA-GagM only homologous vaccination regimens. The heterologous vaccination also generated a more balanced and persistent CD4+ and CD8+ T cell Gag-specific IFN-γ ELISPOT response with a predominant effector memory phenotype. A Th1 bias was induced by the vaccines as determined by the predominant secretion of IFN-γ, TNF-α, and IL-2. This study shows that a low dose of MVA (104 pfu can effectively boost a BCG prime expressing the same mosaic immunogen, generating strong, cellular immune responses against Gag in mice. Our data warrants further evaluation in non-human primates. A low dose vaccine would be an advantage in the resource limited countries of sub-Saharan Africa and India (where the predominating virus is HIV-1 subtype C.

  17. Expansion of myeloid-derived suppressor cells promotes differentiation of regulatory T cells in HIV-1+ individuals.

    Science.gov (United States)

    Wang, Ling; Zhao, Juan; Ren, Jun P; Wu, Xiao Y; Morrison, Zheng D; Elgazzar, Mohamed A; Ning, Shun B; Moorman, Jonathan P; Yao, Zhi Q

    2016-06-19

    Regulatory T cells (Tregs) contribute to HIV-1 disease progression by impairing antiviral immunity; however, the precise mechanisms responsible for the development of Tregs in the setting of HIV-1 infection are incompletely understood. In this study, we provide evidence that HIV-induced expansion of monocytic myeloid-derived suppressor cells (M-MDSCs) promote the differentiation of Foxp3 Tregs. We measured MDSC induction and cytokine expression by flow cytometry and analyzed their functions by coculturing experiments. We observed a dramatic increase in M-MDSC frequencies in the peripheral blood of HIV-1 seropositive (HIV-1) individuals, even in those on antiretroviral therapy with undetectable viremia, when compared with healthy participants. We also observed increases in M-MDSCs after incubating healthy peripheral mononuclear cells (PBMCs) with HIV-1 proteins (gp120 or Tat) or Toll-like receptor 4 ligand lipopolysaccharides in vitro, an effect that could be abrogated in the presence of the phosphorylated signal transducer and activator of transcription 3 inhibitor, STA-21. Functional analyses indicated that M-MDSCs from HIV-1 individuals express higher levels of IL-10, tumor growth factor-β, IL-4 receptor α, p47, programmed death-ligand 1, and phosphorylated signal transducer and activator of transcription 3 - all of which are known mediators of myelopoiesis and immunosuppression. Importantly, incubation of healthy CD4 T cells with MDSCs derived from HIV-1 individuals significantly increased differentiation of Foxp3 Tregs. In addition, depletion of MDSCs from PBMCs of HIV-1 individuals led to a significant reduction of Foxp3 Tregs and increase of IFNγ production by CD4 T effector cells. These results suggest that HIV-induced MDSCs promote Treg cell development and inhibit T cell function - a hallmark of many chronic infectious diseases.

  18. TatE as a Regular Constituent of Bacterial Twin-arginine Protein Translocases.

    Science.gov (United States)

    Eimer, Ekaterina; Fröbel, Julia; Blümmel, Anne-Sophie; Müller, Matthias

    2015-12-01

    Twin-arginine translocation (Tat) systems mediate the transmembrane translocation of completely folded proteins that possess a conserved twin-arginine (RR) motif in their signal sequences. Many Tat systems consist of three essential membrane components named TatA, TatB, and TatC. It is not understood why some bacteria, in addition, constitutively express a functional paralog of TatA called TatE. Here we show, in live Escherichia coli cells, that, upon expression of a Tat substrate protein, fluorescently labeled TatE-GFP relocates from a rather uniform distribution in the plasma membrane into a number of discrete clusters. Clustering strictly required an intact RR signal peptide and the presence of the TatABC subunits, suggesting that TatE-GFP associates with functional Tat translocases. In support of this notion, site-specific photo cross-linking revealed interactions of TatE with TatA, TatB, and TatC. The same approach also disclosed a pronounced tendency of TatE and TatA to hetero-oligomerize. Under in vitro conditions, we found that TatE replaces TatA inefficiently. Our collective results are consistent with TatE being a regular constituent of the Tat translocase in E. coli.

  19. Synthesis of a new class of HIV-1 inhibitors.

    Science.gov (United States)

    Farese-Di Giorgio, A; Pairot, S; Patino, N; Condom, R; Di Giorgio, C; Aumelas, A; Aubertin, A M; Guedj, R

    1999-02-01

    A new family of molecules potentially inhibitors of the HIV-1 Tat-TAR complex was prepared. These compounds are constituted by dinucleotide analogs (PNA dimer) bound, through a linker, to an arginine residue. In this series, several molecules inhibit viral development in cell culture with a micromolar IC50 and without cellular toxicity until 200 microM concentration.

  20. Statins disrupt CCR5 and RANTES expression levels in CD4(+ T lymphocytes in vitro and preferentially decrease infection of R5 versus X4 HIV-1.

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    Alexey A Nabatov

    Full Text Available BACKGROUND: Statins have previously been shown to reduce the in vitro infection of human immunodeficiency virus type 1 (HIV-1 through modulation of Rho GTPase activity and lipid raft formation at the cell surface, as well as by disrupting LFA-1 incorporation into viral particles. PRINCIPLE FINDINGS: Here we demonstrate that treatment of an enriched CD4(+ lymphocyte population with lovastatin (Lov, mevastatin (Mev and simvastatin (activated and non-activated, Sim(A and Sim(N, respectively can reduce the cell surface expression of the CC-chemokine receptor CCR5 (P<0.01 for Sim(A and Lov. The lowered CCR5 expression was associated with down-regulation of CCR5 mRNA expression. The CC-chemokine RANTES protein and mRNA expression levels were slightly increased in CD4(+ enriched lymphocytes treated with statins. Both R5 and X4 HIV-1 were reduced for their infection of statin-treated cells; however, in cultures where statins were removed and where a decrease in CCR5 expression was observed, there was a preferential inhibition of infection with an R5 versus X4 virus. CONCLUSIONS: The results indicate that the modulation of CC-chemokine receptor (CCR5 and CC-chemokine (RANTES expression levels should be considered as contributing to the anti-viral effects of statins, preferentially inhibiting R5 viruses. This observation, in combination with the immunomodulatory activity exerted by statins, suggests they may possess more potent anti-HIV-1 activity when applied during the early stages of infection or in lowering viral transmission. Alternatively, statin treatment could be considered as a way to modulate immune induction such as during vaccination protocols.

  1. Visualization of X4- and R5-Tropic HIV-1 Viruses Expressing Fluorescent Proteins in Human Endometrial Cells: Application to Tropism Study.

    Science.gov (United States)

    Terrasse, Rachel; Memmi, Meriam; Palle, Sabine; Heyndrickx, Leo; Vanham, Guido; Pozzetto, Bruno; Bourlet, Thomas

    2017-01-01

    Worldwide most HIV infections occur through heterosexual transmission, involving complex interactions of cell-free and cell-associated particles with cells of the female genital tract mucosa. The ability of HIV-1 to "infect" epithelial cells remains poorly understood. To address this question, replicative-competent chimeric constructs expressing fluorescent proteins and harboring the envelope of X4- or R5-tropic HIV-1 strains were used to "infect" endometrial HEC1-A cells. The virus-cell interactions were visualized using confocal microscopy (CM) at various times post infection. Combined with quantification of viral RNA and total HIV DNA in infected cells, the CM pictures suggest that epithelial cells do not support a complete viral replication cycle: X4-tropic viruses are imported into the nucleus in a non-productive way, whereas R5-tropic viruses transit through the cytoplasm without replication and are preferentially transmitted to susceptible activated peripheral blood mononuclear cells. Within the limit of experiments conducted in vitro on a continued cell line, these results indicate that the epithelial mucosa may participate to the selection of HIV-1 strains at the mucosal level.

  2. CD26/dipeptidyl peptidase IV (CD26/DPPIV is highly expressed in peripheral blood of HIV-1 exposed uninfected Female sex workers

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    Meyers Adrienne FA

    2010-11-01

    Full Text Available Abstract Background Design of effective vaccines against the human immunodeficiency virus (HIV-1 continues to present formidable challenges. However, individuals who are exposed HIV-1 but do not get infected may reveal correlates of protection that may inform on effective vaccine design. A preliminary gene expression analysis of HIV resistant female sex workers (HIV-R suggested a high expression CD26/DPPIV gene. Previous studies have indicated an anti-HIV effect of high CD26/DPPIV expressing cells in vitro. Similarly, high CD26/DPPIV protein levels in vivo have been shown to be a risk factor for type 2 diabetes. We carried out a study to confirm if the high CD26/DPPIV gene expression among the HIV-R were concordant with high blood protein levels and its correlation with clinical type 2 diabetes and other perturbations in the insulin signaling pathway. Results A quantitative CD26/DPPIV plasma analysis from 100 HIV-R, 100 HIV infected (HIV + and 100 HIV negative controls (HIV Neg showed a significantly elevated CD26/DPPIV concentration among the HIV-R group (mean 1315 ng/ml than the HIV Neg (910 ng/ml and HIV + (870 ng/ml, p Conclusion HIV resistant sex workers have a high expression of CD26/DPPIV in tandem with lowered immune activation markers. This may suggest a novel role for CD26/DPPIV in protection against HIV infection in vivo.

  3. HIV-1 Vif Protein Mediates the Degradation of APOBEC3G in Fission Yeast When Over-expressed Using Codon Optimization

    Institute of Scientific and Technical Information of China (English)

    Lin LI; Jing-yun LI; Hong-shuai SUI; Richard Y. Zhao; Yong-jian LIU; Zuo-yi BAO; Si-yang LIU; Dao-min ZHUANG

    2008-01-01

    Interaction between the HIV-1 Vif protein and the cellular host APOBEC3G protein is a promising target for inhibition of HIV-1 replication. Considering that human cells are a very complicated environment for the study of protein interactions, the goal of this study was to check whether fission yeast could be used as a model cell for studying the Vif-APOBEC3G interaction. Vif and APOBEC3G were expressed in fusion with GFP protein in the S. pombe SP223 strain. Subcellular localizations of Vif and APOBEC3G were observed with fluorescent microscopy. Codon optimization was used to over express the Vif protein in S. pombe cells. The degradation of APOBEC3G mediated by Vif was tested through expressing Vif and GFP-APOBEC3G proteins in the same cell. Western Blot analysis was used to measure the corresponding protein levels under different experimental conditions. The results showed that the Vif protein was predominantly localized in the nucleus of S.pombe cells, APOBEC3G was localized in the cytoplasm and concentrated at punctate bodies that were often in close proximity to the nucleus but were not necessarily restricted from other regions in the cytoplasm. Vif protein expression levels were increased significantly by using codon optimization and APOBEC3G was degraded when Vif was over-expressed in the same S. pombe cells. These results indicate that fission yeast is a good model for studying the interaction between the Vif and APOBEC3G proteins.

  4. [Influence of Opiate Abuse on Expression of Toll-like Receptor 9 in Peripheral Blood Mononuclear Cells of HIV-1-Infected Individuals].

    Science.gov (United States)

    Pan, Peijiang; Wei, Fumei; Jiang, Junjun; Liang, Bingyu; Huang, Jiegang; Liao, Yanyan; Su, Jinming; Li, Yu; Yang, Xiaoyi; Chen, Hui; Ye, Li; Liang, Hao

    2015-03-01

    The aim of this study was to investigate the influence of opiate abuse on the expression of Toll-like receptor 9 (TLR9) in the peripheral blood mononuclear cells (PBMCs) of HIV-1-infected patients and to elucidate possible mechanisms involved in the enhancement of HIV-1 replication by opiate abuse. A total of 200 participants were enrolled in the study by random selection from methadone treatment centers and voluntary HIV counseling and testing centers in the cities of Nanning, Liuzhou, and Qinzhou. These participants included 50 HIV-positive opiate abusers (Opiates HIV(+) group), 50 HIV-negative opiate abusers (Opiates HIV(-) group), 50 HIV-positive subjects who were not opiate abusers (Non-opiates HIV (+) group), and 50 HIV-negative subjects who were not opiate abusers (Control group). PBMCs were isolated from the peripheral blood samples from the subjects and the expression levels of TLR9 mRNA and protein were determined by q-PCR and western blot respectively. There was no significant difference among the four groups in age, gender, nationality, domicile, marital status, educational background or duration of drug abuse (P > 0.05). The median viral loads of the Opiates HIV(+) were significantly higher than those of the Non-Opiates HIV(+) groups (4.450 x 10(3) and 3.977 x 10(3) copies/mL respectively, P Opiates HIV(+), Non-Opiates HIV(+), Opiates HIV(-) and Control groups were (2.13 +/- 1.59) x 10(-3), (3.66 +/- 2.22) x 10(-3), (1.96 +/- 1.42) x 10(-3) and (7.66 +/- 4.87) x 10(-3), respectively. The expression of TLR9 mRNA was significantly lower in both HIV-1-infected and -uninfected groups of opiate abusers compared with groups of non-abusers (P Opiates HIV(+) group and the Opiates HIV(-) group (P > 0.05). However, in the non-opiate groups, the expression levels of TLR9 mRNA in the HIV(+) group were significantly lower than that of the control group (POpiates HIV(+), Non-Opiates HIV(+), and Opiates HIV(-) groups compared to the control group. These results

  5. Selection of HIV-1 gp41 epitope and tandem expression of two epitopes gene%我国HIV-1流行株gp41抗原表位筛选与串联表达

    Institute of Scientific and Technical Information of China (English)

    冯福民; 李敬云; 鲍作义; 刘思扬; 李林; 庄道民

    2005-01-01

    目的探讨HIV-1 gp41抗原表位串联表达蛋白用于HIV抗体检测的可行性. 方法用HIV-1 gp41蛋白亲和层析柱制备HIV-1感染者血清中的多克隆抗体,用噬菌体展示随机十二肽库进行生物淘洗,反向吸附非特异性噬菌体.经ELISA鉴定阳性克隆,DNA测序,确定优势表位.将优势表位与文献报道的另一个优势表位串联,克隆入pQE30载体进行蛋白表达. 结果成功筛选到位于HIV-1 gp41蛋白上的优势抗原表位(YGPKDAETTAIW),串联表位(YGPKDAETTAIW-GGGS-SCSAKFTCTTQI)在pQE30载体中实现可溶性表达.重组蛋白具有良好的抗原性,能与不同的HIV-1抗体阳性血清呈特异反应. 结论 HIV-1 gp41抗原表位串联表达设计是可行的,串联表位重组蛋白可用于HIV-1抗体检测,但检测灵敏性低于常规方法.

  6. Efficient production of HIV-1 virus-like particles from a mammalian expression vector requires the N-terminal capsid domain.

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    Pascal Jalaguier

    Full Text Available It is now well accepted that the structural protein Pr55(Gag is sufficient by itself to produce HIV-1 virus-like particles (VLPs. This polyprotein precursor contains different domains including matrix, capsid, SP1, nucleocapsid, SP2 and p6. In the present study, we wanted to determine by mutagenesis which region(s is essential to the production of VLPs when Pr55(Gag is inserted in a mammalian expression vector, which allows studying the protein of interest in the absence of other viral proteins. To do so, we first studied a minimal Pr55(Gag sequence called Gag min that was used previously. We found that Gag min fails to produce VLPs when expressed in an expression vector instead of within a molecular clone. This failure occurs early in the cell at the assembly of viral proteins. We then generated a series of deletion and substitution mutants, and examined their ability to produce VLPs by combining biochemical and microscopic approaches. We demonstrate that the matrix region is not necessary, but that the efficiency of VLP production depends strongly on the presence of its basic region. Moreover, the presence of the N-terminal domain of capsid is required for VLP production when Gag is expressed alone. These findings, combined with previous observations indicating that HIV-1 Pr55(Gag-derived VLPs act as potent stimulators of innate and acquired immunity, make the use of this strategy worth considering for vaccine development.

  7. Imperatorin inhibits HIV-1 replication through an Sp1-dependent pathway.

    Science.gov (United States)

    Sancho, Rocío; Márquez, Nieves; Gómez-Gonzalo, Marta; Calzado, Marco A; Bettoni, Giorgio; Coiras, Maria Teresa; Alcamí, José; López-Cabrera, Manuel; Appendino, Giovanni; Muñoz, Eduardo

    2004-09-03

    Coumarins and structurally related compounds have been recently shown to present anti-human immunodeficiency virus, type 1 (HIV-1) activity. Among them, the dietary furanocoumarin imperatorin is present in citrus fruits, in culinary herbs, and in some medicinal plants. In this study we report that imperatorin inhibits either vesicular stomatitis virus-pseudotyped or gp160-enveloped recombinant HIV-1 infection in several T cell lines and in HeLa cells. These recombinant viruses express luciferase as a marker of viral replication. Imperatorin did not inhibit the reverse transcription nor the integration steps in the viral cell cycle. Using several 5' long terminal repeat-HIV-1 constructs where critical response elements were either deleted or mutated, we found that the transcription factor Sp1 is critical for the inhibitory activity of imperatorin induced by both phorbol 12-myristate 13-acetate and HIV-1 Tat. Moreover in transient transfections imperatorin specifically inhibited phorbol 12-myristate 13-acetate-induced transcriptional activity of the Gal4-Sp1 fusion protein. Since Sp1 is also implicated in cell cycle progression we further studied the effect of imperatorin on cyclin D1 gene transcription and protein expression and in HeLa cell cycle progression. We found that imperatorin strongly inhibited cyclin D1 expression and arrested the cells at the G(1) phase of the cell cycle. These results highlight the potential of Sp1 transcription factor as a target for natural anti-HIV-1 compounds such as furanocoumarins that might have a potential therapeutic role in the management of AIDS.

  8. Nanoparticles containing siRNA to silence CD4 and CCR5 reduce expression of these receptors and inhibit HIV-1 infection in human female reproductive tract tissue explants

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    Susan K. Eszterhas

    2011-09-01

    Full Text Available Human Immunodeficiency Virus-type 1 (HIV- 1 binds to CD4 and CCR5 receptors on target cells in the human female reproductive tract. We sought to determine whether reducing levels of messenger RNA (mRNA transcripts that encode these receptors in female reproductive tract cells could protect mucosal tissue explants from HIV- 1 infection. Explants prepared from the endometrium, endocervix, and ectocervix of hysterectomy tissues from HIV-1 sero-negative women were exposed to nanoparticles containing CD4- and CCR5-specific short-interfering RNA (siRNA sequences. Explants were then exposed two days later to HIV-1, and HIV-1 reverse transcripts were measured five days post-infection. Explants treated with nanoparticles containing CD4- and CCR5-specific siRNA showed reduced levels of CD4 and CCR5 transcripts, and significantly lower levels of HIV-1 reverse transcripts compared to those treated with an irrelevant siRNA. In female reproductive tract explants and in peripheral blood cell cultures, siRNA transfection induced the secretion of IFN-alpha (IFN-α, a potent antiviral cytokine. In female mice, murine-specific Cd4-siRNA nanoparticles instilled within the uterus significantly reduced murine Cd4 transcripts by day 3. Our findings demonstrate that siRNA nanoparticles reduce expression of HIV-1 infectivity receptors in human female reproductive tract tissues and also inhibit HIV-1 infection. Murine studies demonstrate that nanoparticles can penetrate the reproductive tract tissues in vivo and silence gene expression. The induction of IFN-α after siRNA transfection can potentially contribute to the antiviral effect. These findings support the therapeutic development of nanoparticles to deliver siRNA molecules to silence host cell receptors in the female reproductive tract as a novel microbicide to inhibit mucosal HIV-1 transmission.

  9. HIV-1 envelope glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

    2017-08-22

    The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

  10. Psychoneuroimmunology and HIV-1.

    Science.gov (United States)

    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…

  11. Differential expression of Werner and Bloom syndrome genes in the peripheral blood of HIV-1 infected patients.

    Science.gov (United States)

    Bordi, Licia; Gioia, Cristiana; Lalle, Eleonora; Piselli, Pierluca; Poccia, Fabrizio; Capobianchi, Maria R; Amendola, Alessandra

    2007-02-01

    Human immunodeficiency virus (HIV)-induced immunodeficiency and immune-system aging share some analogies. Since Werner (WRN) and Bloom (BLM) helicases are crucial in cell repair and aging, their peripheral blood mononuclear cells (PBMC) mRNA levels were compared in HIV-1 infected patients and in normal donors. The mean levels of WRN mRNA were 3.7-fold higher in PBMCs from HIV-1 infected individuals in comparison to healthy donors, whereas BLM mRNA mean levels were slightly higher, although not significantly. WRN increase was positively correlated to CD4 and CD8 T-cell numbers, and also the percentage of naive T lymphocytes, and was observed also in T-cell subsets. Interestingly, a general trend toward increased WRN mRNA levels in individuals with lower viral load was observed, without association with patient age, time of seroconversion, and on/off antiretroviral therapy regimen. On the whole, this study shows that WRN and BLM are differentially modulated in HIV infection, as WRN--but not BLM--is significantly increased, suggesting that mechanisms different from defect or loss of helicase function, observed in WRN and BLM syndromes, may be at the basis of T-cell aging in HIV infection.

  12. APOBEC3G-UBA2 fusion as a potential strategy for stable expression of APOBEC3G and inhibition of HIV-1 replication

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    Li Lin

    2008-08-01

    Full Text Available Abstract Background Although APOBEC3G protein is a potent and innate anti-HIV-1 cellular factor, HIV-1 Vif counteracts the effect of APOBEC3G by promoting its degradation through proteasome-mediated proteolysis. Thus, any means that could prevent APOBEC3G degradation could potentially enhance its anti-viral effect. The UBA2 domain has been identified as an intrinsic stabilization signal that protects protein from proteasomal degradation. In this pilot study, we tested whether APOBEC3G, when it is fused with UBA2, can resist Vif-mediated proteasomal degradation and further inhibit HIV-1 infection. Results APOBEC3G-UBA2 fusion protein is indeed more resistant to Vif-mediated degradation than APOBEC3G. The ability of UBA2 domain to stabilize APOBEC3G was diminished when polyubiquitin was over-expressed and the APOBEC3G-UBA2 fusion protein was found to bind less polyubiquitin than APOBEC3G, suggesting that UBA2 stabilizes APOBEC3G by preventing ubiquitin chain elongation and proteasome-mediated proteolysis. Consistently, treatment of cells with a proteasome inhibitor MG132 alleviated protein degradation of APOBEC3G and APOBEC3G-UBA2 fusion proteins. Analysis of the effect of APOBEC3G-UBA2 fusion protein on viral infectivity indicated that infection of virus packaged from HEK293 cells expressing APOBEC3G-UBA2 fusion protein is significantly lower than those packaged from HEK293 cells over-producing APOBEC3G or APOBEC3G-UBA2 mutant fusion proteins. Conclusion Fusion of UBA2 to APOBEC3G can make it more difficult to be degraded by proteasome. Thus, UBA2 could potentially be used to antagonize Vif-mediated APOBEC3G degradation by preventing polyubiquitination. The stabilized APOBEC3G-UBA2 fusion protein gives stronger inhibitory effect on viral infectivity than APOBEC3G without UBA2.

  13. Structural conformation of prokaryotic plasmid expressing the gp41 of HIV-1 SF2 strain%HIV-1 SF2株env基因(gp41)的克隆构建及其原核表达

    Institute of Scientific and Technical Information of China (English)

    董梅; 鲁晓青; 陈向伟; 王斌

    2001-01-01

    目的克隆并在大肠杆菌中表达HIV gp41.方法应用PCR技术,纯化HIV-1 SF2株外膜蛋白env基因(gp41),并重组入原核高效表达载体pBV220,在大肠杆菌HB101中进行表达.结果 SDS-PAGE电泳结果表明,在44 000处有一条蛋白表达带.Western blot证明,44 000蛋白带可与HIV-1阳性血清发生特异性反应.结论该重组表达gp41的融合蛋白,可为HIV-1 gp41.

  14. HIV-1 and SIV Predominantly Use CCR5 Expressed on a Precursor Population to Establish Infection in T Follicular Helper Cells

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    John Zaunders

    2017-04-01

    Full Text Available BackgroundT follicular helper (Tfh cells are increasingly recognized as a major reservoir of HIV infection that will likely need to be addressed in approaches to curing HIV. However, Tfh express minimal CCR5, the major coreceptor for HIV-1, and the mechanism by which they are infected is unclear. We have previously shown that macaque Tfh lack CCR5, but are infected in vivo with CCR5-using SIV at levels comparable to other memory CD4+ T cells. Similarly, human splenic Tfh cells are highly infected with HIV-1 DNA. Therefore, we set out to examine the mechanism of infection of Tfh cells.MethodologyTfh and other CD4+ T cell subsets from macaque lymph nodes and spleens, splenic Tfh from HIV+ subjects, and tonsillar Tfh from HIV-uninfected subjects were isolated by cell sorting prior to cell surface and molecular characterization. HIV proviral gp120 sequences were submitted to genotypic and phenotypic tropism assays. Entry of CCR5- and CXCR4-using viruses into Tfh from uninfected tonsillar tissue was measured using a fusion assay.ResultsPhylogenetic analysis, genotypic, and phenotypic analysis showed that splenic Tfh cells from chronic HIV+ subjects were predominantly infected with CCR5-using viruses. In macaques, purified CCR5+PD-1intermediate(int+ memory CD4+ T cells were shown to include pre-Tfh cells capable of differentiating in vitro to Tfh by upregulation of PD-1 and Bcl6, confirmed by qRT-PCR and single-cell multiplex PCR. Infected PD-1int cells survive, carry SIV provirus, and differentiate into PD-1hi Tfh after T cell receptor stimulation, suggesting a pathway for SIV infection of Tfh. In addition, a small subset of macaque and human PD-1hi Tfh can express low levels of CCR5, which makes them susceptible to infection. Fusion assays demonstrated CCR5-using HIV-1 entry into CCR5+ Tfh and pre-Tfh cells from human tonsils.ConclusionThe major route of infection of Tfh in macaques and humans appears to be via a CCR5-expressing pre-Tfh population

  15. Making a Short Story Long: Regulation of P-TEFb and HIV-1 Transcriptional Elongation in CD4+ T Lymphocytes and Macrophages

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    Andrew P. Rice

    2012-06-01

    Full Text Available Productive transcription of the integrated HIV-1 provirus is restricted by cellular factors that inhibit RNA polymerase II elongation. The viral Tat protein overcomes this by recruiting a general elongation factor, P-TEFb, to the TAR RNA element that forms at the 5’ end of nascent viral transcripts. P-TEFb exists in multiple complexes in cells, and its core consists of a kinase, Cdk9, and a regulatory subunit, either Cyclin T1 or Cyclin T2. Tat binds directly to Cyclin T1 and thereby targets the Cyclin T1/P-TEFb complex that phosphorylates the CTD of RNA polymerase II and the negative factors that inhibit elongation, resulting in efficient transcriptional elongation. P-TEFb is tightly regulated in cells infected by HIV-1—CD4+ T lymphocytes and monocytes/macrophages. A number of mechanisms have been identified that inhibit P-TEFb in resting CD4+ T lymphocytes and monocytes, including miRNAs that repress Cyclin T1 protein expression and dephosphorylation of residue Thr186 in the Cdk9 T-loop. These repressive mechanisms are overcome upon T cell activation and macrophage differentiation when the permissivity for HIV-1 replication is greatly increased. This review will summarize what is currently known about mechanisms that regulate P-TEFb and how this regulation impacts HIV-1 replication and latency.

  16. SIRT1 regulates HIV transcription via Tat deacetylation.

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    Sara Pagans

    2005-02-01

    Full Text Available The human immunodeficiency virus (HIV Tat protein is acetylated by the transcriptional coactivator p300, a necessary step in Tat-mediated transactivation. We report here that Tat is deacetylated by human sirtuin 1 (SIRT1, a nicotinamide adenine dinucleotide-dependent class III protein deacetylase in vitro and in vivo. Tat and SIRT1 coimmunoprecipitate and synergistically activate the HIV promoter. Conversely, knockdown of SIRT1 via small interfering RNAs or treatment with a novel small molecule inhibitor of the SIRT1 deacetylase activity inhibit Tat-mediated transactivation of the HIV long terminal repeat. Tat transactivation is defective in SIRT1-null mouse embryonic fibroblasts and can be rescued by expression of SIRT1. These results support a model in which cycles of Tat acetylation and deacetylation regulate HIV transcription. SIRT1 recycles Tat to its unacetylated form and acts as a transcriptional coactivator during Tat transactivation.

  17. The Vpr protein from HIV-1: distinct roles along the viral life cycle

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    Benichou Serge

    2005-02-01

    Full Text Available Abstract The genomes of human and simian immunodeficiency viruses (HIV and SIV encode the gag, pol and env genes and contain at least six supplementary open reading frames termed tat, rev, nef, vif, vpr, vpx and vpu. While the tat and rev genes encode regulatory proteins absolutely required for virus replication, nef, vif, vpr, vpx and vpu encode for small proteins referred to "auxiliary" (or "accessory", since their expression is usually dispensable for virus growth in many in vitro systems. However, these auxiliary proteins are essential for viral replication and pathogenesis in vivo. The two vpr- and vpx-related genes are found only in members of the HIV-2/SIVsm/SIVmac group, whereas primate lentiviruses from other lineages (HIV-1, SIVcpz, SIVagm, SIVmnd and SIVsyk contain a single vpr gene. In this review, we will mainly focus on vpr from HIV-1 and discuss the most recent developments in our understanding of Vpr functions and its role during the virus replication cycle.

  18. Prokaryotic Expression and Functional Study of HIV-1 Envelope Glycoprotein gp41 Helical Bundle%HIV-1跨膜蛋白gp41螺旋结构的原核表达及功能研究

    Institute of Scientific and Technical Information of China (English)

    刘斌; 何红秋; 程绍辉; 陈慰祖; 王存新

    2008-01-01

    HIV-1跨膜蛋白gp41是HIV-1包膜与靶细胞膜的融合过程中的关键蛋白,是理想的HIV-1融合抑制剂靶点.为开展以gr41为靶点的抑制剂筛选,以HIV-1 B亚型病毒基因为模板,通过PCR、酶切、连接等方法构建得到gp41 5-helix与6-helix重组质粒,转入大肠杆菌BL21(DE3)进行表述,经变性和复性后亲和层析纯化蛋白.经SDS-PAGE鉴定,纯化后蛋白纯度较高.通过非变性凝胶电泳证明gp415-helix与C-多肽衍生物T-20存在相互作用,为下一步药物筛选模型的建立奠定了基础.

  19. Beneficial Effects of cART Initiated during Primary and Chronic HIV-1 Infection on Immunoglobulin-Expression of Memory B-Cell Subsets

    Science.gov (United States)

    Pensieroso, Simone; Tolazzi, Monica; Chiappetta, Stefania; Nozza, Silvia; Lazzarin, Adriano; Tambussi, Giuseppe; Scarlatti, Gabriella

    2015-01-01

    Introduction During HIV-1 infection the B-cell compartment undergoes profound changes towards terminal differentiation, which are only partially restored by antiretroviral therapy (cART). Materials and Methods To investigate the impact of infection as early as during primary HIV-1 infection (PHI) we assessed distribution of B-cell subsets in 19 PHI and 25 chronic HIV-1-infected (CHI) individuals before and during 48 weeks of cART as compared to healthy controls (n = 23). We also analysed Immunoglobulin-expression of memory B-cell subsets to identify alterations in Immunoglobulin-maturation. Results Determination of B-cell subsets at baseline showed that total and Naive B-cells were decreased whereas Activated Memory (AM), Tissue-like Memory (TLM) B-cells and Plasma cells were increased in both PHI and CHI patients. After 4 weeks of cART total B-cells increased, while AM, TLM B-cells and Plasma cells decreased, although without reaching normal levels in either group of individuals. This trend was maintained until week 48, though only total B-cells normalized in both PHI and CHI. Resting Memory (RM) B-cells were preserved since baseline. This subset remained stable in CHI, while was expanded by an early initiation of cART during PHI. Untreated CHI patients showed IgM-overexpression at the expenses of switched (IgM-IgD-) phenotypes of the memory subsets. Interestingly, in PHI patients a significant alteration of Immunoglobulin-expression was evident at BL in TLM cells, and after 4 weeks, despite treatment, in AM and RM subsets. After 48 weeks of therapy, Immunoglobulin-expression of AM and RM almost normalized, but remained perturbed in TLM cells in both groups. Conclusions In conclusion, aberrant activated and exhausted B-cell phenotypes rose already during PHI, while most of the alterations in Ig-expression seen in CHI appeared later, despite 4 weeks of effective cART. After 48 weeks of cART B-cell subsets distribution improved although without full normalization

  20. Beneficial Effects of cART Initiated during Primary and Chronic HIV-1 Infection on Immunoglobulin-Expression of Memory B-Cell Subsets.

    Directory of Open Access Journals (Sweden)

    Manuela Pogliaghi

    Full Text Available During HIV-1 infection the B-cell compartment undergoes profound changes towards terminal differentiation, which are only partially restored by antiretroviral therapy (cART.To investigate the impact of infection as early as during primary HIV-1 infection (PHI we assessed distribution of B-cell subsets in 19 PHI and 25 chronic HIV-1-infected (CHI individuals before and during 48 weeks of cART as compared to healthy controls (n = 23. We also analysed Immunoglobulin-expression of memory B-cell subsets to identify alterations in Immunoglobulin-maturation.Determination of B-cell subsets at baseline showed that total and Naive B-cells were decreased whereas Activated Memory (AM, Tissue-like Memory (TLM B-cells and Plasma cells were increased in both PHI and CHI patients. After 4 weeks of cART total B-cells increased, while AM, TLM B-cells and Plasma cells decreased, although without reaching normal levels in either group of individuals. This trend was maintained until week 48, though only total B-cells normalized in both PHI and CHI. Resting Memory (RM B-cells were preserved since baseline. This subset remained stable in CHI, while was expanded by an early initiation of cART during PHI. Untreated CHI patients showed IgM-overexpression at the expenses of switched (IgM-IgD- phenotypes of the memory subsets. Interestingly, in PHI patients a significant alteration of Immunoglobulin-expression was evident at BL in TLM cells, and after 4 weeks, despite treatment, in AM and RM subsets. After 48 weeks of therapy, Immunoglobulin-expression of AM and RM almost normalized, but remained perturbed in TLM cells in both groups.In conclusion, aberrant activated and exhausted B-cell phenotypes rose already during PHI, while most of the alterations in Ig-expression seen in CHI appeared later, despite 4 weeks of effective cART. After 48 weeks of cART B-cell subsets distribution improved although without full normalization, while Immunoglobulin-expression normalized

  1. Immunogenicity of a novel Clade B HIV-1 vaccine combination: Results of phase 1 randomized placebo controlled trial of an HIV-1 GM-CSF-expressing DNA prime with a modified vaccinia Ankara vaccine boost in healthy HIV-1 uninfected adults.

    Science.gov (United States)

    Buchbinder, Susan P; Grunenberg, Nicole A; Sanchez, Brittany J; Seaton, Kelly E; Ferrari, Guido; Moody, M Anthony; Frahm, Nicole; Montefiori, David C; Hay, Christine M; Goepfert, Paul A; Baden, Lindsey R; Robinson, Harriet L; Yu, Xuesong; Gilbert, Peter B; McElrath, M Juliana; Huang, Yunda; Tomaras, Georgia D

    2017-01-01

    A phase 1 trial of a clade B HIV vaccine in HIV-uninfected adults evaluated the safety and immunogenicity of a DNA prime co-expressing GM-CSF (Dg) followed by different numbers and intervals of modified vaccinia Ankara Boosts (M). Both vaccines produce virus-like particles presenting membrane-bound Env. Four US sites randomized 48 participants to receiving 1/10th the DNA dose as DgDgMMM given at 0, 2, 4, 6 and 8 months, or full dose DgDgM_M or DgDgMM_M regimens, given at 0, 2, 4, and 8 months, and 0, 2, 4, 6, and 10 months, respectively. Peak immunogenicity was measured 2 weeks post-last vaccination. All regimens were well tolerated and safe. Full dose DgDgM_M and DgDgMM_M regimens generated Env-specific IgG to HIV-1 Env in >90%, IgG3 in >80%, and IgA in vaccine without GM-CSF. This DNA/MVA prime-boost regimen induced durable, functional humoral responses that included ADCC, high antibody avidity, and Env IgG1 and IgG3 binding responses to the immunodominant region of gp41. The third, spaced MVA boost improved the overall quality of the antibody response. These products without co-expressed GM-CSF but combined with protein boosts will be considered for efficacy evaluation. ClinicalTrials.gov NCT01571960.

  2. Cytoplasmic Dynein Promotes HIV-1 Uncoating

    Directory of Open Access Journals (Sweden)

    Paulina Pawlica

    2014-11-01

    Full Text Available Retroviral capsid (CA cores undergo uncoating during their retrograde transport (toward the nucleus, and/or after reaching the nuclear membrane. However, whether HIV-1 CA core uncoating is dependent upon its transport is not understood. There is some evidence that HIV-1 cores retrograde transport involves cytoplasmic dynein complexes translocating on microtubules. Here we investigate the role of dynein-dependent transport in HIV-1 uncoating. To interfere with dynein function, we depleted dynein heavy chain (DHC using RNA interference, and we over-expressed p50/dynamitin. In immunofluorescence microscopy experiments, DHC depletion caused an accumulation of CA foci in HIV-1 infected cells. Using a biochemical assay to monitor HIV-1 CA core disassembly in infected cells, we observed an increase in amounts of intact (pelletable CA cores upon DHC depletion or p50 over-expression. Results from these two complementary assays suggest that inhibiting dynein-mediated transport interferes with HIV-1 uncoating in infected cells, indicating the existence of a functional link between HIV-1 transport and uncoating.

  3. Destabilization of the TAR hairpin leads to extension of the polyA hairpin and inhibition of HIV-1 polyadenylation

    NARCIS (Netherlands)

    Vrolijk, M.M.; Harwig, A.; Berkhout, B.; Das, A.T.

    2009-01-01

    ABSTRACT: BACKGROUND: Two hairpin structures that are present at both the 5' and 3' end of the HIV-1 RNA genome have important functions in the viral life cycle. The TAR hairpin binds the viral Tat protein and is essential for Tat-mediated activation of transcription. The adjacent polyA hairpin

  4. HIV-1跨膜蛋白gp41重组抗原的表达及其免疫反应性%HIV-1 transmembrane glycoprotein 41:Expression of recombinant antigen and antigenicity analysis

    Institute of Scientific and Technical Information of China (English)

    王林定; 付碧石; 李宝林; 钟平

    2008-01-01

    目的 为开发和建立敏感、特异的抗HIV-1抗体的检测方法研制重组gp41抗原.方法 根据HIV-1的基因序列,设计并合成了1对PCR扩增引物,应用PCR技术从HIV-1 外膜基因组中扩增出HIV-1的gp41截短体,将扩增的基因片段插入质粒pET-28a中构建成重组表达质粒pET-gp41.诱导表达并纯化gp41重组抗原,对gp41进行了初步应用分析.结果 gp41在大肠埃希菌BL21 (DE3)中获得高表达,表达量占菌体总蛋白量的26.08%.纯化后截短体gp41的纯度为97.94%.经间接ELISA和免疫印迹检测,纯化后的表达产物gp41具有很高的抗原特异性和免疫反应性.结论 研制的重组抗原gp41有较强的抗原性和潜在的应用价值.

  5. THE SECOND IMMUNODOMINANT EPITOPES OF HIV-1 GP41: EFFICIENT EXPRESSION IN E. coli%HIV-1 GP41第二优势表位簇在大肠杆菌中的高效表达

    Institute of Scientific and Technical Information of China (English)

    李文利; 钱冬萌; 王斌

    2003-01-01

    ①目的构建HIV-1 SF2株跨膜蛋白GP41第二优势表位簇基因的原核高效表达克隆,探讨提高原核表达的途径.②方法根据密码子的兼并性,利用PCR-定点突变技术扩增、改造目的基因片段,将其与原核表达载体pGEX4T-2经EcoRI和SalI双酶切、连接,重组质粒pGEX4T-2/SE转化表达宿主菌DH5α,经IPTG诱导表达出目的融合蛋白,经SDS-PAGE与Western-Blot鉴定.③结果获得了高效表达HIV-1 GP41第二优势表位谷胱甘肽S-转移酶融合蛋白的重组菌;Western-Blot鉴定表明,重组蛋白具有良好的抗原性和特异性.④结论在原核表达体系中可以高效表达HIV-1 GP41第二优势表位簇.

  6. HIV-1Nef调节内皮细胞黏附分子ICAM-1的表达%HIV-1Nef up-regulates the expression of adhesion molecule ICAM-1 on endothelial cells

    Institute of Scientific and Technical Information of China (English)

    杨凡; 刘朝奇; 覃晓琳; 吕佰瑞; 周永芹; 韩钰

    2010-01-01

    目的 研究HIV-1的调节基因Nef对ECV304细胞ICAM-1表达的影响,从而为分析HIV-1感染引起内皮细胞生物学活性的变化,以及为阐明Nef参与HIV-1致病的分子机制奠定基础.方法 应用本实验室已经建立保存的HIV-1Nef基因在内皮细胞的稳定表达细胞株ECV304-Nef和其阴性对照细胞株ECV304 pcDNA 3.1(+),通过RT-PCR、实时定量PCR(real-time PCR)、Western blot、FCM和细胞黏附试验分析ECV304-Nef细胞ICAM-1的表达水平.结果 RT-PCR、real-time PCR结果 显示ECV304-Nef细胞ICAM-1 mRNA表达水平明显升高,为对照组的(4.3±0.2)倍;Western blot结果 示ECV304-Nef细胞Ⅰ-CAM-1蛋白的表达水平高于对照组;FCM分析显示ECV304-Nef细胞和对照组细胞ICAM-1阳性细胞百分率分别为(35.3±2.2)%和(12.5±0.8)%(P<0.01),两组间ICAM-1表达有显著差异.细胞黏附实验观察到ECV304-Nef细胞黏附的Jurkat细胞数明显多于对照组,荧光仪定量分析结果 显示ECV 304-Nef细胞黏附的Jurkat细胞的荧光强度值显著高与对照组(P<0.05).结论 本实验证实了HIV-1 Nef基因可以上调血管内皮细胞细胞黏附分子ICAM-1的表达.

  7. HIV-1 target cells in the CNS

    OpenAIRE

    Joseph, Sarah B.; Arrildt, Kathryn T.; Sturdevant, Christa B.; Swanstrom, Ronald

    2014-01-01

    HIV-1 replication in the central nervous system (CNS) is typically limited by the availability of target cells. HIV-1 variants that are transmitted and dominate the early stages of infection almost exclusively use the CCR5 coreceptor and are well adapted to entering, and thus infecting, cells expressing high CD4 densities similar to those found on CD4+ T cells. While the “immune privileged” CNS is largely devoid of CD4+ T cells, macrophage and microglia are abundant throughout ...

  8. Synergistic cooperation between methamphetamine and HIV-1 gsp120 through the P13K/Akt pathway induces IL-6 but not IL-8 expression in astrocytes.

    Directory of Open Access Journals (Sweden)

    Ankit Shah

    Full Text Available HIV-1 envelope protein gp120 has been extensively studied for neurotoxic effects that have been attributed to the increased expression of various proinflammatory cytokines in the CNS. Recently we have shown that methamphetamine (MA also increases expression of proinflammatory cytokines in astrocytes. However, combined effect of gp120 and MA is not known. The present study was undertaken to determine cumulative effect and the mechanism(s/pathways involved in the functional interaction between gp120 and MA in SVGA astrocytes. Our results clearly suggest that gp120 and MA affect IL-6 but not IL-8 in a synergistic manner and this synergy was mediated by PI3K/Akt and NF-κB pathways. Inhibition of either of these pathways could abrogate the increased expression of IL-6 due to MA or gp120 alone, as well as the increased expression of IL-6 when the astrocytes were treated with both gp120 and MA. These results were confirmed by both, using chemical inhibitors/siRNA as well as western blotting. This study therefore provides novel information regarding the interaction between MA and gp120 in terms of the expression of IL-6 and the mechanisms underlying potential synergy between MA and gp120 in astrocytes.

  9. Characterization of two candidate genes, NCoA3 and IRF8, potentially involved in the control of HIV-1 latency

    Directory of Open Access Journals (Sweden)

    Gumez Audrey

    2005-11-01

    Full Text Available Abstract Background The persistence of latent HIV-1 reservoirs is the principal barrier preventing the eradication of HIV-1 infection in patients by current antiretroviral therapy. It is thus crucial to understand the molecular mechanisms involved in the establishment, maintenance and reactivation of HIV-1 latency. Since chromatin remodeling has been implicated in the transcriptional reactivation of the HIV-1 promoter, we assessed the role of the histone deacetylase inhibitor sodium butyrate (NaB on two HIV-1 latently infected cell lines (U1 and ACH-2 gene expression. Results Analysis of microarrays data led us to select two candidate genes: NCoA3 (Nuclear Receptor Coactivator 3, a nuclear receptor coactivator and IRF8 (Interferon Regulatory Factor 8, an interferon regulatory factor. NCoA3 gene expression is upregulated following NaB treatment of latently infected cells whereas IRF8 gene expression is strongly downregulated in the promonocytic cell line following NaB treatment. Their differential expressions were confirmed at the transcriptional and translational levels. Moreover, NCoA3 gene expression was also upregulated after treatment of U1 and ACH-2 cells with phorbol myristyl acetate (PMA but not trichostatin A (TSA and after treatment with NaB of two others HIV-1 latently infected cell lines (OM10.1 and J1.1. IRF8 gene is only expressed in U1 cells and was also downregulated after treatment with PMA or TSA. Functional analyses confirmed that NCoA3 synergizes with Tat to enhance HIV-1 promoter transcription and that IRF8 represses the IRF1-mediated activation through the HIV-1 promoter Interferon-stimulated response element (ISRE. Conclusion These results led us to postulate that NCoA3 could be involved in the transcriptional reactivation of the HIV-1 promoter from latency and that IRF8 may contribute to the maintenance of the latent state in the promonocytic cell line. Implication of these factors in the maintenance or reactivation of the

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

    Energy Technology Data Exchange (ETDEWEB)

    Di Nunzio, Francesca, E-mail: francesca.di-nunzio@pasteur.fr [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Fricke, Thomas [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States); Miccio, Annarita [University of Modena e Reggio Emilia, Centro di Medicina Rigenerativa, Modena (Italy); Valle-Casuso, Jose Carlos; Perez, Patricio [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States); Souque, Philippe [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Rizzi, Ermanno; Severgnini, Marco [Institute of Biomedical Technologies, CNR, Milano (Italy); Mavilio, Fulvio [University of Modena e Reggio Emilia, Centro di Medicina Rigenerativa, Modena (Italy); Genethon, Evry (France); Charneau, Pierre [Molecular Virology and Vaccinology unit, CNRS URA 3015, Department of Virology, Institut Pasteur, 25-28 rue du Dr. Roux, 75015 Paris (France); Diaz-Griffero, Felipe, E-mail: felipe.diaz-griffero@einstein.yu.edu [Department of Microbiology and Immunology, Albert Einstein College of Medicine Bronx, NY 10461 (United States)

    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. SAMHD1 restricts HIV-1 infection in dendritic cells (DCs by dNTP depletion, but its expression in DCs and primary CD4+ T-lymphocytes cannot be upregulated by interferons

    Directory of Open Access Journals (Sweden)

    St Gelais Corine

    2012-12-01

    Full Text Available Abstract Background SAMHD1 is an HIV-1 restriction factor in non-dividing monocytes, dendritic cells (DCs, macrophages, and resting CD4+ T-cells. Acting as a deoxynucleoside triphosphate (dNTP triphosphohydrolase, SAMHD1 hydrolyzes dNTPs and restricts HIV-1 infection in macrophages and resting CD4+ T-cells by decreasing the intracellular dNTP pool. However, the intracellular dNTP pool in DCs and its regulation by SAMHD1 remain unclear. SAMHD1 has been reported as a type I interferon (IFN-inducible protein, but whether type I IFNs upregulate SAMHD1 expression in primary DCs and CD4+ T-lymphocytes is unknown. Results Here, we report that SAMHD1 significantly blocked single-cycle and replication-competent HIV-1 infection of DCs by decreasing the intracellular dNTP pool and thereby limiting the accumulation of HIV-1 late reverse transcription products. Type I IFN treatment did not upregulate endogenous SAMHD1 expression in primary DCs or CD4+ T-lymphocytes, but did in HEK 293T and HeLa cell lines. When SAMHD1 was over-expressed in these two cell lines to achieve higher levels than that in DCs, no HIV-1 restriction was observed despite partially reducing the intracellular dNTP pool. Conclusions Our results suggest that SAMHD1-mediated reduction of the intracellular dNTP pool in DCs is a common mechanism of HIV-1 restriction in myeloid cells. Endogenous expression of SAMHD1 in primary DCs or CD4+ T-lymphocytes is not upregulated by type I IFNs.

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

    Science.gov (United States)

    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.

  13. Detection, characterization and regulation of antisense transcripts in HIV-1

    Directory of Open Access Journals (Sweden)

    Mesnard Jean-Michel

    2007-10-01

    Full Text Available Abstract Background We and others have recently demonstrated that the human retrovirus HTLV-I was producing a spliced antisense transcript, which led to the synthesis of the HBZ protein. The objective of the present study was to demonstrate the existence of antisense transcription in HIV-1 and to provide a better characterization of the transcript and its regulation. Results Initial experiments conducted by standard RT-PCR analysis in latently infected J1.1 cell line and pNL4.3-transfected 293T cells confirmed the existence of antisense transcription in HIV-1. A more adapted RT-PCR protocol with limited RT-PCR artefacts also led to a successful detection of antisense transcripts in several infected cell lines. RACE analyses demonstrated the existence of several transcription initiation sites mapping near the 5' border of the 3'LTR (in the antisense strand. Interestingly, a new polyA signal was identified on the antisense strand and harboured the polyA signal consensus sequence. Transfection experiments in 293T and Jurkat cells with an antisense luciferase-expressing NL4.3 proviral DNA showed luciferase reporter gene expression, which was further induced by various T-cell activators. In addition, the viral Tat protein was found to be a positive modulator of antisense transcription by transient and stable transfections of this proviral DNA construct. RT-PCR analyses in 293T cells stably transfected with a pNL4.3-derived construct further confirmed these results. Infection of 293T, Jurkat, SupT1, U937 and CEMT4 cells with pseudotyped virions produced from the antisense luciferase-expressing NL4.3 DNA clone led to the production of an AZT-sensitive luciferase signal, which was however less pronounced than the signal from NL4.3Luc-infected cells. Conclusion These results demonstrate for the first time that antisense transcription exists in HIV-1 in the context of infection. Possible translation of the predicted antisense ORF in this transcript should

  14. HIV-1病毒感染因子基因克隆、表达、纯化及其抗体制备的研究%Cloning, expression and purification of HIV-1 Vif, and its antibodies production

    Institute of Scientific and Technical Information of China (English)

    李岚; 杨怡姝; 张晓光; 张晓梅; 李泽琳; 曾毅

    2006-01-01

    目的 制备HIV-1病毒感染因子(Vif)及其抗体.方法 用PCR技术从HIV-1 NL4.3cDNA质粒中扩增病毒感染因子(vif)基因,vif基因全长为579 nt(核苷酸),翻译成含192个氨基酸的蛋白质.将测序鉴定过的vif基因克隆到原核表达载体pET-32a上,以包涵体的形式在大肠埃希菌BL21(DE3)中高效表达,Vif蛋白C端融合6×His标签便于纯化及鉴定.应用酶切鉴定、SDS-PAGE及Western Blot等方法确保基因片段的正确性及表达蛋白的特异性.间接ELISA法测定兔多克隆抗体滴度.结果 成功地获得了高纯度的Vif融合蛋白,纯度可达80%以上.用其制备多克隆抗体滴度可达1:204 800.结论 获得高纯度的Vif融合蛋白及其高效价的抗体.

  15. Molecular cloning of a novel human I-mfa domain-containing protein that differently regulates human T-cell leukemia virus type I and HIV-1 expression.

    Science.gov (United States)

    Thébault, S; Gachon, F; Lemasson, I; Devaux, C; Mesnard, J M

    2000-02-18

    Regulation of viral genome expression is the result of complex cooperation between viral proteins and host cell factors. We report here the characterization of a novel cellular factor sharing homology with the specific cysteine-rich C-terminal domain of the basic helix-loop-helix repressor protein I-mfa. The synthesis of this new factor, called HIC for Human I-mfa domain-Containing protein, is controlled at the translational level by two different codons, an ATG and an upstream non-ATG translational initiator, allowing the production of two protein isoforms, p32 and p40, respectively. We show that the HIC protein isoforms present different subcellular localizations, p32 being mainly distributed throughout the cytoplasm, whereas p40 is targeted to the nucleolus. Moreover, in trying to understand the function of HIC, we have found that both isoforms stimulate in T-cells the expression of a luciferase reporter gene driven by the human T-cell leukemia virus type I-long terminal repeat in the presence of the viral transactivator Tax. We demonstrate by mutagenesis that the I-mfa-like domain of HIC is involved in this regulation. Finally, we also show that HIC is able to down-regulate the luciferase expression from the human immunodeficiency virus type 1-long terminal repeat induced by the viral transactivator Tat. From these results, we propose that HIC and I-mfa represent two members of a new family of proteins regulating gene expression and characterized by a particular cysteine-rich C-terminal domain.

  16. Cloning and expressing of HIV-1 Vif gene in prokaryotic cells, and evaluation of its bioactivity%HIV-1 Vif的克隆、表达与活性检测

    Institute of Scientific and Technical Information of China (English)

    覃晓琳; 刘朝奇; 刘徽婷; 汪龚泽

    2010-01-01

    目的 克隆HIV-1 Vif基因,构建原核表达质粒,进行蛋白的表达及其生物学活性的检测.方法 PCR扩增Vif基因,并将其克隆到原核表达载体pET28a(+)中,构建原核表达质粒pET28a(+)/Vif,进行双酶切及测序鉴定.获得的阳性质粒转化大肠杆菌BL21(DE3)中进行表达,对表达产物进行SDS-PAGE电泳和Western blot检测分析,利用亲和层析方法纯化Vif蛋白.利用Pull-Down方法检测HIV-1 Vif与SH3(HCK)特异性结合活性.结果 通过酶切和测序,结果表明重组质粒pET28a(+)/Vif构建正确.SDS-PAGE和Western blot结果鉴定了原核表达的Vif重组蛋白大小正确.纯化了蛋白Vif、SH3和GST.GST pull-down试验说明Vif和SH3蛋白具有体外特异性结合活性.结论 成功地克隆、表达和纯化了Vif蛋白,Vif与SH3蛋白具有结合活性,为进一步研究针对Vif与SH3结合的药物筛选提供实验依据.

  17. Assessment of HIV-1 entry inhibitors by MLV/HIV-1 pseudotyped vectors

    Directory of Open Access Journals (Sweden)

    Thaler Sonja

    2005-09-01

    Full Text Available Abstract Background Murine leukemia virus (MLV vector particles can be pseudotyped with a truncated variant of the human immunodeficiency virus type 1 (HIV-1 envelope protein (Env and selectively target gene transfer to human cells expressing both CD4 and an appropriate co-receptor. Vector transduction mimics the HIV-1 entry process and is therefore a safe tool to study HIV-1 entry. Results Using FLY cells, which express the MLV gag and pol genes, we generated stable producer cell lines that express the HIV-1 envelope gene and a retroviral vector genome encoding the green fluorescent protein (GFP. The BH10 or 89.6 P HIV-1 Env was expressed from a bicistronic vector which allowed the rapid selection of stable cell lines. A codon-usage-optimized synthetic env gene permitted high, Rev-independent Env expression. Vectors generated by these producer cells displayed different sensitivity to entry inhibitors. Conclusion These data illustrate that MLV/HIV-1 vectors are a valuable screening system for entry inhibitors or neutralizing antisera generated by vaccines.

  18. Non-covalent ligand conjugation to biotinylated DNA nanoparticles using TAT peptide genetically fused to monovalent streptavidin.

    Science.gov (United States)

    Sun, Wenchao; Fletcher, David; van Heeckeren, Rolf Christiaan; Davis, Pamela B

    2012-09-01

    DNA nanoparticles (DNA NPs), which self-assemble from DNA plasmids and poly-L-lysine (pLL)-polyethylene glycol (PEG) block copolymers, transfect several cell types in vitro and in vivo with minimal toxicity and immune response. To further enhance the gene transfer efficiency of DNA NP and control its tropism, we established a strategy to efficiently attach peptide ligands to DNA NPs. The non-covalent biotin-streptavidin (SA) interaction was used for ligand conjugation to overcome problems associated with covalent conjugation methods. A fusion protein of SA with the HIV-1 TAT peptide was cloned, expressed, purified and attached to biotinylated DNA NPs. A modified SA system with tetrameric structure but monovalent biotin binding capacity was adopted and shown to reduce the aggregation of biotinylated DNA NPs compared to neutravidin. Compared to unmodified DNA NPs, TAT modified DNA NPs significantly enhanced in vitro gene transfer, particularly at low DNA concentrations. Studies of cellular uptake and cellular distribution of the DNA NPs indicated that attaching TAT enhanced binding of DNA NPs to cell surface but not internalization at high DNA concentrations. In vivo studies showed that TAT modified DNA NPs mediated equal level of gene transfer to the mouse airways via the luminal route compared to unmodified DNA NPs.

  19. TatBC-independent TatA/Tat substrate interactions contribute to transport efficiency.

    Directory of Open Access Journals (Sweden)

    Johannes Taubert

    Full Text Available The Tat system can transport folded, signal peptide-containing proteins (Tat substrates across energized membranes of prokaryotes and plant plastids. A twin-arginine motif in the signal peptide of Tat substrates is recognized by TatC-containing complexes, and TatA permits the membrane passage. Often, as in the model Tat systems of Escherichia coli and plant plastids, a third component - TatB - is involved that resembles TatA but has a higher affinity to TatC. It is not known why most TatA dissociates from TatBC complexes in vivo and distributes more evenly in the membrane. Here we show a TatBC-independent substrate-binding to TatA from Escherichia coli, and we provide evidence that this binding enhances Tat transport. First hints came from in vivo cross-linking data, which could be confirmed by affinity co-purification of TatA with the natural Tat substrates HiPIP and NrfC. Two positions on the surface of HiPIP could be identified that are important for the TatA interaction and transport efficiency, indicating physiological relevance of the interaction. Distributed TatA thus may serve to accompany membrane-interacting Tat substrates to the few TatBC spots in the cells.

  20. Determination of the minimal amount of Tat activity required for human immunodeficiency virus type 1 replication.

    Science.gov (United States)

    Verhoef, K; Koper, M; Berkhout, B

    1997-10-27

    The Tat protein of human immunodeficiency virus type 1 (HIV-1) is a potent trans-activator of transcription from the viral LTR promoter. Previous mutagenesis studies have identified domains within Tat responsible for binding to its TAR RNA target and for transcriptional activation. The minimal Tat activation domain is composed of the N-terminal 48 residues, and mutational analyses identified a cluster of critical cysteines. The importance of four highly conserved aromatic amino acids within the activation domain has not been thoroughly investigated. We have systematically substituted these aromatic residues (Y26, F32, F38, Y47) of the HIV-1 LAI Tat protein with other aromatic residues (conservative mutation) or alanine (nonconservative mutation). The activity of the mutant Tat constructs was measured in different cell lines by transfection with a LTR-CAT reporter plasmid. The range of transcriptional activities measured for this set of Tat mutants allowed careful assessment of the level of Tat activity required for optimal viral replication. To test this, the mutant Tat genes were introduced into the pLAI infectious molecular clone and tested for their effect on virus replication in a T-cell line. We found that a twofold reduction in Tat activity already affects viral replication, and no virus replication was measured for Tat mutants with less than 15% activity. This strict correlation between Tat activity and viral replication demonstrates the importance of the Tat function to viral fitness. Interestingly, a less pronounced replication defect was observed in primary cell types. This finding may correlate with the frequent detection of proviruses with Tat-inactivating mutations in clinical samples. Copyright 1997 Academic Press.

  1. Alterations in the expression of DEAD-box and other RNA binding proteins during HIV-1 replication

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    Zeichner Steven L

    2004-12-01

    Full Text Available Abstract Recent results showed that certain DEAD box protein RNA helicases, DDX3 and DDX1, play an important role in the HIV infection cycle by facilitating the export of long, singly spliced or unspliced HIV RNAs from the nucleus via the CRM1-Rev pathway. Close examination of an extensive microarray expression profiling dataset obtained from cells latently infected with HIV induced to undergo lytic viral replication indicated that additional DEAD box proteins, beyond DDX3 and DDX1, exhibit differential expression during lytic HIV replication, and in latently infected cells prior to induction into active replication. This finding provides additional evidence that the involvement of DEAD box proteins and other RNA-binding proteins may play roles in active HIV replication and in the control of viral latency. Agents targeting these functions may offer new approaches to antiretroviral therapy and the therapeutic manipulation of HIV latency.

  2. The Effect of Root, Shoot and Seed Extracts of The Iranian Thymus L. (Family: Lamiaceae) Species on HIV-1 Replication and CD4 Expression

    OpenAIRE

    Maryam Soleimani Farsani; Mandana Behbahani; Hamid Zarkesh Isfahani

    2016-01-01

    Objective The genus Thymus L. is a cushion plant that was previously used for the treatment of bronchitis and rheumatism. The present investigation was carried out to study the effects of root, shoot, leaf and seed extracts of five Thymus species and subspecies on peripheral blood mononuclear cells (PBMCs) toxicity and HIV-1 replication. Materials and Methods In this experimental study, the activity of the Thymus extracts on HIV-1 replication and lymphocytes population were examin...

  3. High-level HIV-1 Nef transient expression in Nicotiana benthamiana using the P19 gene silencing suppressor protein of Artichoke Mottled Crinckle Virus

    Directory of Open Access Journals (Sweden)

    Bianco Linda

    2009-11-01

    Full Text Available Abstract Background In recent years, different HIV antigens have been successfully expressed in plants by either stable transformation or transient expression systems. Among HIV proteins, Nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. Attempts to express Nef as a single protein product (not fused to a stabilizing protein in transgenic plants resulted in disappointingly low yields (about 0.5% of total soluble protein. In this work we describe a transient expression system based on co-agroinfiltration of plant virus gene silencing suppressor proteins in Nicotiana benthamiana, followed by a two-step affinity purification protocol of plant-derived Nef. Results The effect of three gene silencing viral suppressor proteins (P25 of Potato Virus X, P19 of either Artichoke Mottled Crinckle virus and Tomato Bushy Stunt virus on Nef transient expression yield was evaluated. The P19 protein of Artichoke Mottled Crinckle virus (AMCV-P19 gave the highest expression yield in vacuum co-agroinfiltration experiments reaching 1.3% of total soluble protein, a level almost three times higher than that previously reported in stable transgenic plants. The high yield observed in the co-agroinfiltrated plants was correlated to a remarkable decrease of Nef-specific small interfering RNAs (siRNAs indicating an effective modulation of RNA silencing mechanisms by AMCV-P19. Interestingly, we also showed that expression levels in top leaves of vacuum co-agroinfiltrated plants were noticeably reduced compared to bottom leaves. Moreover, purification of Nef from agroinfiltrated tissue was achieved by a two-step immobilized metal ion affinity chromatography protocol with yields of 250 ng/g of fresh tissue. Conclusion We demonstrated that expression level of HIV-1 Nef in plant can be improved using a transient expression system enhanced by the AMCV-P19 gene silencing suppressor

  4. Generation of H9 T-cells stably expressing a membrane-bound form of the cytoplasmic tail of the Env-glycoprotein: lack of transcomplementation of defective HIV-1 virions encoding C-terminally truncated Env

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    Bosch Valerie

    2006-05-01

    Full Text Available Abstract H9-T-cells do not support the replication of mutant HIV-1 encoding Env protein lacking its long cytoplasmic C-terminal domain (Env-CT. Here we describe the generation of a H9-T-cell population constitutively expressing the HIV-1 Env-CT protein domain anchored in the cellular membrane by it homologous membrane-spanning domain (TMD. We confirmed that the Env-TMD-CT protein was associated with cellular membranes, that its expression did not have any obvious cytotoxic effects on the cells and that it did not affect wild-type HIV-1 replication. However, as measured in both a single-round assay as well as in spreading infections, replication competence of mutant pNL-Tr712, lacking the Env-CT, was not restored in this H9 T-cell population. This means that the Env-CT per se cannot transcomplement the replication block of HIV-1 virions encoding C-terminally truncated Env proteins and suggests that the Env-CT likely exerts its function only in the context of the complete Env protein.

  5. An inducible packaging cell system for safe, efficient lentiviral vector production in the absence of HIV-1 accessory proteins.

    Science.gov (United States)

    Pacchia, A L; Adelson, M E; Kaul, M; Ron, Y; Dougherty, J P

    2001-03-30

    Lentiviral vectors based on human immunodeficiency virus type 1 (HIV-1) possess the ability to deliver exogenous genes to both dividing and nondividing cells and to subsequently establish a stable provirus in these target cells, which can allow long-term expression of the transferred gene. Herein we describe a stable packaging cell line that is devoid of HIV-1 tat, vif, vpr, vpu, and nef. In order to avoid any risk of cytotoxicity associated with constitutive expression of HIV-1 protease or the VSV-G envelope protein, transcription of the packaging and envelope constructs was tightly controlled by employing the ecdysone-inducible system. Using this cell line, we have been able to consistently generate concentrated pseudotyped vector virus stocks with titers in the range of 10(8) IU/ml, which can efficiently transduce actively dividing and growth-arrested cells in vitro. This novel packaging cell line for lentiviral vectors facilitates the production of high-titer virus stocks in the absence of replication-competent virus and provides us with an important tool for use in future gene transfer studies.

  6. TAT-Cytoglobin融合蛋白的原核表达、纯化及生物活性分析%Expression, purification, and characterization of fusion protein TAT-Cytoglobin

    Institute of Scientific and Technical Information of China (English)

    张如婧; 李招发; 施伟杰; 许瑞安

    2014-01-01

    旨在利用细胞穿膜肽TAT的穿膜作用和细胞珠蛋白(Cytoglobin,Cygb)的抗衰老、抗纤维化的功能,将二者通过基因工程的手段融合在一起,以期获得能够穿透细胞屏障的Cygb.通过两次重叠PCR技术获得了TAT-Cygb DNA,将其插入原核表达载体pET22b质粒中,转化至大肠杆菌BL-21,筛选出可表达TAT-Cygb融合蛋白的大肠杆菌工程菌株.经乳糖诱导表达TAT-Cygb,CM阳离子交换层析(CM Sepharose Fast Flow Protocol)获得纯度高达95%的TAT-Cygb融合蛋白,分子量约23 kDa.生物活性实验显示,TAT-Cygb过氧化物酶比活力达到(422.30±0.36) U/mg.TAT-Cygb预处理的Hacat细胞可免受H2O2氧化应激的损伤(RGR=100%),同时TAT-Cygb可治疗已被H2O2氧化损伤的细胞(RGR=98%),与Cygb处理组相比具有显著差异(RGR=79%).该研究首次成功利用大肠杆菌表达系统表达了可穿透细胞膜的、有生物活性的TAT-Cygb融合蛋白,为继续开展Cygb在抗衰老、抗纤维化和抗癌领域的研究奠定了基础.

  7. Oropharyngeal Candidiasis in HIV Infection: Analysis of Impaired Mucosal Immune Response to Candida albicans in Mice Expressing the HIV-1 Transgene

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    Louis de Repentigny

    2015-06-01

    Full Text Available IL-17-producing Th17 cells are of critical importance in host defense against oropharyngeal candidiasis (OPC. Speculation about defective Th17 responses to oral C. albicans infection in the context of HIV infection prompted an investigation of innate and adaptive immune responses to Candida albicans in transgenic mice expressing the genome of HIV-1 in immune cells and displaying an AIDS-like disease. Defective IL-17 and IL-22-dependent mucosal responses to C. albicans were found to determine susceptibility to OPC in these transgenic mice. Innate phagocytes were quantitatively and functionally intact, and individually dispensable for control of OPC and to prevent systemic dissemination of Candida to deep organs. CD8+ T-cells recruited to the oral mucosa of the transgenic mice limited the proliferation of C. albicans in these conditions of CD4+ T-cell deficiency. Therefore, the immunopathogenesis of OPC in the context of HIV infection involves defective T-cell-mediated immunity, failure of crosstalk with innate mucosal immune effector mechanisms, and compensatory cell responses, which limit Candida infection to the oral mucosa and prevent systemic dissemination.

  8. Identification of HIV-1 specific T lymphocyte responses in highly exposed persistently seronegative Chinese

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-wei; SHAO Yi-ming; HONG Kun-xue; MA Jun; YUAN Lin; LIU Sha; CHEN Jian-ping; ZHANG Yuan-zhi; RUAN Yu-hua; XU Jian-qing

    2006-01-01

    Background Studies of highly exposed persistently seronegative (HEPS) individuals may provide valuable information on mechanisms of protection and on vaccine design. Cellular immune responses play a critical role in containing human immunodeficiency virus. However, the cellular immune responses in HEPS individuals have not been thoroughly assessed at the entire viral genome level.Methods Ten HEPS Chinese with a history of frequent penetrative vaginal intercourse (mean frequency, at least once a week), with some unprotected sexual contact occurring in the weeks or days immediately before enrollment, 25 HIV-1 seropositive individuals, 10 HIV-1-seronegative healthy individuals with low-risk sexual behavior and no history suggestive of exposure to HIV-1 infection were enrolled. HIV-1-specific T cell responses were comprehensively analyzed by an interferon- γ Elispot assay against 770 overlapping peptides spanning all HIV-1 proteins.Results HIV-1-specific T-cell responses of interferon- γ secretion were identified in 3 (30%) out of 10 HEPS individuals; the specific cytotoxic T lymphocytes were targeted at Pol (2/10), Env (2/10), and Tat (1/10).HIV-1-specific T-cell responses of interferon- γ secretion were identified in 20 (80%) out of 25 seropositive intravenous drug users (IDUs), revealing that all HIV-1 proteins and protein subunits could serve as targets for HIV-1-specific CD8+ T cell responses with 85% recognizing Gag, 80% recognizing Nef, 75% recognizing Pol,60% recognizing Env, 55% recognizing Vpu, 45% recognizing Vpr, 20% recognizing Vif, 20% recognizing Tat and 15% recognizing Rev in these seropositive individuals. None of the seronegative healthy individuals gave the positive T-cell responses.Conclusions About 30% of HEPS Chinese mounted HIV-1 specific T cell immune responses. Cell-mediated immunity against HIV-1 may be developed through non-productive infections.

  9. Localization of the Tat translocon components in Escherichia coli.

    Science.gov (United States)

    Berthelmann, Felix; Brüser, Thomas

    2004-07-02

    The Tat system has the ability to translocate folded proteins across the bacterial cytoplasmic membrane. In Escherichia coli, three functionally different translocon components have been identified, namely TatA, TatB, and TatC. These proteins were fused to the green fluorescent protein (GFP) and their localization was determined by confocal laser scanning fluorescence microscopy. TatA-GFP was distributed in the membrane, often with higher abundance at the poles. TatB-GFP was found in distinct spots at the poles of the cells. The fluorescence of TatC-GFP was very low and required a constitutive expression system to become higher than background, but then appearing polar. All three constructs complemented the chain-formation phenotype of corresponding mutant strains, indicating the functionality of the fusion proteins. TatB-GFP and TatC-GFP also complemented TMAO respiration deficiency and TatA-GFP the SDS-sensitivity of the mutant strains. The localization of the translocon-GFP fusions coincides with the fluorescence pattern of GFP fusions to Tat substrate signal sequences. We suggest that the active translocon complexes are mainly present at polar positions in Escherichia coli.

  10. Pertussis toxin B-oligomer suppresses IL-6 induced HIV-1 and chemokine expression in chronically infected U1 cells via inhibition of activator protein 1.

    Science.gov (United States)

    Rizzi, Chiara; Crippa, Massimo P; Jeeninga, Rienk E; Berkhout, Ben; Blasi, Francesco; Poli, Guido; Alfano, Massimo

    2006-01-15

    Pertussis toxin B-oligomer (PTX-B) inhibits HIV replication in T lymphocytes and monocyte-derived macrophages by interfering with multiple steps of the HIV life cycle. PTX-B prevents CCR5-dependent (R5) virus entry in a noncompetitive manner, and it also exerts suppressive effects on both R5- and CXCR4-dependent HIV expression at a less-characterized postentry level. We demonstrate in this study that PTX-B profoundly inhibits HIV expression in chronically infected promonocytic U1 cells stimulated with several cytokines and, particularly, the IL-6-mediated effect, a cytokine that triggers viral production in these cells independently of NF-kappaB activation. From U1 cells we have subcloned a cell line, named U1-CR1, with increased responsiveness to IL-6. In these cells, PTX-B neither down-regulated the IL-6R nor prevented IL-6 induced signaling in terms of STAT3 phosphorylation and DNA binding. In contrast, PTX-B inhibited AP-1 binding to target DNA and modified its composition with a proportional increases in FosB, Fra2, and ATF2. PTX-B inhibited IL-6-induced HIV-1 long-terminal repeat-driven transcription from A, C, E, and F viral subtypes, which contain functional AP-1 binding sites, but failed to inhibit transcription from subtypes B and D LTR devoid of these sites. In addition, PTX-B inhibited the secretion of IL-6-induced, AP-1-dependent genes, including urokinase-type plasminogen activator, CXCL8/IL-8, and CCL2/monocyte chemotactic protein-1. Thus, PTX-B suppression of IL-6 induced expression of HIV and cellular genes in chronically infected promonocytic cells is strongly correlated to inhibition of AP-1.

  11. 重组HIV-1跨膜蛋白gp41在大肠杆菌中的表达%EXPRESSION OF HUMAN RECOMBINANT HIV-1 gp41 TRANSMEMBRANE PROTEIN IN E. Coli

    Institute of Scientific and Technical Information of China (English)

    王静; 王斌; 路永波; 王秋波; 张艳丽

    2000-01-01

    ①目的构建重组HIV-1SF2株跨膜蛋白gp41基因片段的原核表达克隆并在大肠杆菌中表达.②方法通过聚合酶链反应(PCR)扩增目的基因,然后用限制性内切酶将其与原核表达载体pMAL-p2定向连接,构建成重组质粒转入大肠杆菌DH5α菌中.经IPTG诱导,SDS-PAGE电泳分析有无重组蛋白表达.③结果获得了重组的原核表达质粒及其表达产物.④结论在pMAL-p2中构建的HIV-lgp41重组质粒可在大肠杆菌中表达.

  12. Inhibition of HIV-1 by curcumin A, a novel curcumin analog

    Directory of Open Access Journals (Sweden)

    Kumari N

    2015-09-01

    Full Text Available Namita Kumari,1,2,* Amol A Kulkarni,3,* Xionghao Lin,2 Charlee McLean,1 Tatiana Ammosova,2 Andrey Ivanov,2 Maria Hipolito,1 Sergei Nekhai,2 Evaristus Nwulia11Translational Neuroscience Laboratory, 2Department of Medicine, Center for Sickle Cell Disease, College of Medicine, 3College of Pharmacy, Howard University, Washington, DC, USA*These authors contributed equally to this study Abstract: Despite the remarkable success of combination antiretroviral therapy at curtailing HIV progression, emergence of drug-resistant viruses, chronic low-grade inflammation, and adverse effects of combination antiretroviral therapy treatments, including metabolic disorders collectively present the impetus for development of newer and safer antiretroviral drugs. Curcumin, a phytochemical compound, was previously reported to have some in vitro anti-HIV and anti-inflammatory activities, but poor bioavailability has limited its clinical utility. To circumvent the bioavailability problem, we derivatized curcumin to sustain retro-aldol decomposition at physiological pH. The lead compound derived, curcumin A, showed increased stability, especially in murine serum where it was stable for up to 25 hours, as compared to curcumin that only had a half-life of 10 hours. Both curcumin and curcumin A showed similar inhibition of one round of HIV-1 infection in cultured lymphoblastoid (also called CEM T cells (IC50=0.7 µM. But in primary peripheral blood mononuclear cells, curcumin A inhibited HIV-1 more potently (IC50=2 µM compared to curcumin (IC50=12 µM. Analysis of specific steps of HIV-1 replication showed that curcumin A inhibited HIV-1 reverse transcription, but had no effect on HIV-1 long terminal repeat basal or Tat-induced transcription, or NF-κB-driven transcription at low concentrations that affected reverse transcription. Finally, we showed curcumin A induced expression of HO-1 and decreased cell cycle progression of T cells. Our findings thus indicate that

  13. Comparative Analysis of Tat-Dependent and Tat-Deficient Natural Lentiviruses

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    Deepanwita Bose

    2015-09-01

    Full Text Available The emergence of human immunodeficiency virus (HIV causing acquired immunodeficiency syndrome (AIDS in infected humans has resulted in a global pandemic that has killed millions. HIV-1 and HIV-2 belong to the lentivirus genus of the Retroviridae family. This genus also includes viruses that infect other vertebrate animals, among them caprine arthritis-encephalitis virus (CAEV and Maedi-Visna virus (MVV, the prototypes of a heterogeneous group of viruses known as small ruminant lentiviruses (SRLVs, affecting both goat and sheep worldwide. Despite their long host-SRLV natural history, SRLVs were never found to be responsible for immunodeficiency in contrast to primate lentiviruses. SRLVs only replicate productively in monocytes/macrophages in infected animals but not in CD4+ T cells. The focus of this review is to examine and compare the biological and pathological properties of SRLVs as prototypic Tat-independent lentiviruses with HIV-1 as prototypic Tat-dependent lentiviruses. Results from this analysis will help to improve the understanding of why and how these two prototypic lentiviruses evolved in opposite directions in term of virulence and pathogenicity. Results may also help develop new strategies based on the attenuation of SRLVs to control the highly pathogenic HIV-1 in humans.

  14. Oral Immunization with a Recombinant Lactococcus lactis-Expressing HIV-1 Antigen on Group A Streptococcus Pilus Induces Strong Mucosal Immunity in the Gut.

    Science.gov (United States)

    Chamcha, Venkateswarlu; Jones, Andrew; Quigley, Bernard R; Scott, June R; Amara, Rama Rao

    2015-11-15

    The induction of a potent humoral and cellular immune response in mucosal tissue is important for the development of an effective HIV vaccine. Most of the current HIV vaccines under development use the i.m. route for immunization, which is relatively poor in generating potent and long-lived mucosal immune responses. In this article, we explore the ability of an oral vaccination with a probiotic organism, Lactococcus lactis, to elicit HIV-specific immune responses in the mucosal and systemic compartments of BALB/c mice. We expressed the HIV-1 Gag-p24 on the tip of the T3 pilus of Streptococcus pyogenes as a fusion to the Cpa protein (LL-Gag). After four monthly LL-Gag oral immunizations, we observed strong Gag-specific IgG and IgA responses in serum, feces, and vaginal secretions. However, the Gag-specific CD8 T cell responses in the blood were at or below our detection limit. After an i.m. modified vaccinia Ankara/Gag boost, we observed robust Gag-specific CD8 T cell responses both in systemic and in mucosal tissues, including intraepithelial and lamina propria lymphocytes of the small intestine, Peyer's patches, and mesenteric lymph nodes. Consistent with strong immunogenicity, the LL-Gag induced activation of CD11c(+) CD11b(+) dendritic cells in the Peyer's patches after oral immunization. Our results demonstrate that oral immunization with L. lactis expressing an Ag on the tip of the group A Streptococcus pilus serves as an excellent vaccine platform to induce strong mucosal humoral and cellular immunity against HIV.

  15. Sequence Analysis of In Vivo-Expressed HIV-1 Spliced RNAs Reveals the Usage of New and Unusual Splice Sites by Viruses of Different Subtypes

    Science.gov (United States)

    Vega, Yolanda; Delgado, Elena; de la Barrera, Jorge; Carrera, Cristina; Zaballos, Ángel; Cuesta, Isabel; Mariño, Ana; Ocampo, Antonio; Miralles, Celia; Pérez-Castro, Sonia; Álvarez, Hortensia; López-Miragaya, Isabel; García-Bodas, Elena; Díez-Fuertes, Francisco; Thomson, Michael M.

    2016-01-01

    HIV-1 RNAs are generated through a complex splicing mechanism, resulting in a great diversity of transcripts, which are classified in three major categories: unspliced, singly spliced (SS), and doubly spliced (DS). Knowledge on HIV-1 RNA splicing in vivo and by non-subtype B viruses is scarce. Here we analyze HIV-1 RNA splice site usage in CD4+CD25+ lymphocytes from HIV-1-infected individuals through pyrosequencing. HIV-1 DS and SS RNAs were amplified by RT-PCR in 19 and 12 samples, respectively. 13,108 sequences from HIV-1 spliced RNAs, derived from viruses of five subtypes (A, B, C, F, G), were identified. In four samples, three of non-B subtypes, five 3’ splice sites (3’ss) mapping to unreported positions in the HIV-1 genome were identified. Two, designated A4i and A4j, were used in 22% and 25% of rev RNAs in two viruses of subtypes B and A, respectively. Given their close proximity (one or two nucleotides) to A4c and A4d, respectively, they could be viewed as variants of these sites. Three 3’ss, designated A7g, A7h, and A7i, located 20, 32, and 18 nucleotides downstream of A7, respectively, were identified in a subtype C (A7g, A7h) and a subtype G (A7i) viruses, each in around 2% of nef RNAs. The new splice sites or variants of splice sites were associated with the usual sequence features of 3’ss. Usage of unusual 3’ss A4d, A4e, A5a, A7a, and A7b was also detected. A4f, previously identified in two subtype C viruses, was preferentially used by rev RNAs of a subtype C virus. These results highlight the great diversity of in vivo splice site usage by HIV-1 RNAs. The fact that four of five newly identified splice sites or variants of splice sites were detected in non-subtype B viruses allows anticipating an even greater diversity of HIV-1 splice site usage than currently known. PMID:27355361

  16. Sequence Analysis of In Vivo-Expressed HIV-1 Spliced RNAs Reveals the Usage of New and Unusual Splice Sites by Viruses of Different Subtypes.

    Directory of Open Access Journals (Sweden)

    Yolanda Vega

    Full Text Available HIV-1 RNAs are generated through a complex splicing mechanism, resulting in a great diversity of transcripts, which are classified in three major categories: unspliced, singly spliced (SS, and doubly spliced (DS. Knowledge on HIV-1 RNA splicing in vivo and by non-subtype B viruses is scarce. Here we analyze HIV-1 RNA splice site usage in CD4+CD25+ lymphocytes from HIV-1-infected individuals through pyrosequencing. HIV-1 DS and SS RNAs were amplified by RT-PCR in 19 and 12 samples, respectively. 13,108 sequences from HIV-1 spliced RNAs, derived from viruses of five subtypes (A, B, C, F, G, were identified. In four samples, three of non-B subtypes, five 3' splice sites (3'ss mapping to unreported positions in the HIV-1 genome were identified. Two, designated A4i and A4j, were used in 22% and 25% of rev RNAs in two viruses of subtypes B and A, respectively. Given their close proximity (one or two nucleotides to A4c and A4d, respectively, they could be viewed as variants of these sites. Three 3'ss, designated A7g, A7h, and A7i, located 20, 32, and 18 nucleotides downstream of A7, respectively, were identified in a subtype C (A7g, A7h and a subtype G (A7i viruses, each in around 2% of nef RNAs. The new splice sites or variants of splice sites were associated with the usual sequence features of 3'ss. Usage of unusual 3'ss A4d, A4e, A5a, A7a, and A7b was also detected. A4f, previously identified in two subtype C viruses, was preferentially used by rev RNAs of a subtype C virus. These results highlight the great diversity of in vivo splice site usage by HIV-1 RNAs. The fact that four of five newly identified splice sites or variants of splice sites were detected in non-subtype B viruses allows anticipating an even greater diversity of HIV-1 splice site usage than currently known.

  17. The Effect of Root, Shoot and Seed Extracts of The Iranian Thymus L. (Family: Lamiaceae Species on HIV-1 Replication and CD4 Expression

    Directory of Open Access Journals (Sweden)

    Maryam Soleimani Farsani

    2016-07-01

    Full Text Available Objective The genus Thymus L. is a cushion plant that was previously used for the treatment of bronchitis and rheumatism. The present investigation was carried out to study the effects of root, shoot, leaf and seed extracts of five Thymus species and subspecies on peripheral blood mononuclear cells (PBMCs toxicity and HIV-1 replication. Materials and Methods In this experimental study, the activity of the Thymus extracts on HIV-1 replication and lymphocytes population were examined respectively using HIV-1 p24 Antigen kit and flow-cytometer. The Thymus species effect was investigated, including Thymus kotschyanus, Thymus vulgaris, Thymus carmanicus, Thymus daenensis subspecies lancifolius and Thymus daenensis subspecies daenensis. Results The effect of root methanol extracts of all species on PBMCs proliferation was significantly higher than the other extracts. The intensity of CD4, CD3 and CD45 were decreased in the presence of all root extracts. Although the average median fluorescence intensity (MFI values of CD19 were increased in the cells treated with these extracts. All methanol extracts showed anti-HIV-1 activity at high concentrations (200 and 500 µg/ml. Anti-HIV-1 activity of Thymus daenensis subspecies daenensis was significantly more than the other species. Conclusion These results demonstrated that root extracts of Thymus species might be a good candidate to investigate anti-HIV infection in vivo.

  18. {sup 123}I-labeled HIV-1 tat peptide radioimmunoconjugates are imported into the nucleus of human breast cancer cells and functionally interact in vitro and in vivo with the cyclin-dependent kinase inhibitor, p21{sup WAF-1/Cip-1}

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Meiduo [University Health Network, Division of Nuclear Medicine, Toronto, ON (Canada); University of Toronto, Department of Pharmaceutical Sciences, Toronto, ON (Canada); Chen, Paul; Wang, Judy; Scollard, Deborah A. [University Health Network, Division of Nuclear Medicine, Toronto, ON (Canada); Vallis, Katherine A. [University Health Network, Department of Radiation Oncology, Toronto, ON (Canada); University of Toronto, Department of Medical Biophysics, Toronto, ON (Canada); Reilly, Raymond M. [University Health Network, Division of Nuclear Medicine, Toronto, ON (Canada); University of Toronto, Department of Pharmaceutical Sciences, Toronto, ON (Canada); University of Toronto, Department of Medical Imaging, Toronto, ON (Canada); University of Toronto, Leslie Dan Faculty of Pharmacy, Toronto, ON (Canada)

    2007-03-15

    To evaluate the internalization and nuclear translocation of {sup 123}I-tat-peptide radioimmunoconjugates in MDA-MB-468 breast cancer cells and their ability to interact with the cyclin-dependent kinase inhibitor, p21{sup WAF-1/Cip-1}. Peptides [GRKKRRQRRRPPQGYGC] harboring the nuclear-localizing sequence from HIV tat domain were conjugated to anti-p21{sup WAF-1/Cip-1} antibodies. Immunoreactivity was assessed by Western blot using lysate from MDA-MB-468 cells exposed to EGF to induce p21{sup WAF-1/Cip-1}. Internalization and nuclear translocation were measured. The ability of tat-anti-p21{sup WAF-1/Cip-1} to block G{sub 1}-S phase arrest in MDA-MB-468 cells caused by EGF-induced p21{sup WAF-1/Cip-1} was evaluated. Tumor and normal tissue uptake were determined at 48 h p.i. in athymic mice implanted s.c. with MDA-MB-468 xenografts injected intratumorally with EGF. There was 13.4{+-}0.2% of radioactivity internalized by MDA-MB-468 cells incubated with {sup 123}I-tat-anti-p21{sup WAF-1/Cip-1} and 34.6{+-}3.1% imported into the nucleus. Tat-anti-p21{sup WAF-1/Cip-1}(8 {mu}M) decreased the proportion of EGF-treated cells in G{sub 1} phase from 81.9{+-}0.7% to 46.1{+-}0.7% (p<0.001), almost restoring the G{sub 1} phase fraction to that of unexposed cells (25.8{+-}0.2%). Non-specific tat-mouse IgG did not block EGF-induced G{sub 1}-S phase arrest. Tumor uptake of radioactivity was higher in mice injected with EGF to induce p21{sup WAF-1/Cip-1} than in mice not receiving EGF (3.1{+-}0.4% versus 1.8{+-}0.2% ID/g; p=0.04). Western blot analysis of tumors revealed a threefold increase in the p21{sup WAF-1/Cip-1}/{beta}-actin ratio. We conclude that intracellular and nuclear epitopes in cancer cells can be functionally targeted with tat-radioimmunoconjugates to exploit many more epitopes for imaging and radiotherapeutic applications than have previously been accessible. (orig.)

  19. Induction of Multifunctional Human Immunodeficiency Virus Type 1 (HIV-1)-Specific T Cells Capable of Proliferation in Healthy Subjects by Using a Prime-Boost Regimen of DNA- and Modified Vaccinia Virus Ankara-Vectored Vaccines Expressing HIV-1 Gag Coupled to CD8+ T-Cell Epitopes†

    Science.gov (United States)

    Goonetilleke, Nilu; Moore, Stephen; Dally, Len; Winstone, Nicola; Cebere, Inese; Mahmoud, Abdul; Pinheiro, Susana; Gillespie, Geraldine; Brown, Denise; Loach, Vanessa; Roberts, Joanna; Guimaraes-Walker, Ana; Hayes, Peter; Loughran, Kelley; Smith, Carole; De Bont, Jan; Verlinde, Carl; Vooijs, Danii; Schmidt, Claudia; Boaz, Mark; Gilmour, Jill; Fast, Pat; Dorrell, Lucy; Hanke, Tomas; McMichael, Andrew J.

    2006-01-01

    A double-blind randomized phase I trial was conducted in human immunodeficiency virus type 1 (HIV-1)-negative subjects receiving vaccines vectored by plasmid DNA and modified vaccinia virus Ankara (MVA) expressing HIV-1 p24/p17 gag linked to a string of CD8+ T-cell epitopes. The trial had two groups. One group received either two doses of MVA.HIVA (2× MVA.HIVA) (n = 8) or two doses of placebo (2× placebo) (n = 4). The second group received 2× pTHr.HIVA followed by one dose of MVA.HIVA (n = 8) or 3× placebo (n = 4). In the pTHr.HIVA-MVA.HIVA group, HIV-1-specific T-cell responses peaked 1 week after MVA.HIVA vaccination in both ex vivo gamma interferon (IFN-γ) ELISPOT (group mean, 210 spot-forming cells/106 cells) and proliferation (group mean stimulation index, 37), with assays detecting positive responses in four out of eight and five out of eight subjects, respectively. No HIV-1-specific T-cell responses were detected in either assay in the 2× MVA.HIVA group or subjects receiving placebo. Using a highly sensitive and reproducible cultured IFN-γ ELISPOT assay, positive responses mainly mediated by CD4+ T cells were detected in eight out of eight vaccinees in the pTHr.HIVA-MVA.HIVA group and four out of eight vaccinees in the 2× MVA.HIVA group. Importantly, no false-positive responses were detected in the eight subjects receiving placebo. Of the 12 responders, 11 developed responses to previously identified immunodominant CD4+ T-cell epitopes, with 6 volunteers having responses to more than one epitope. Five out of 12 responders also developed CD8+ T-cell responses to the epitope string. Induced T cells produced a variety of anti-viral cytokines, including tumor necrosis factor alpha and macrophage inflammatory protein 1β. These data demonstrate that prime-boost vaccination with recombinant DNA and MVA vectors can induce multifunctional HIV-1-specific T cells in the majority of vaccinees. PMID:16641265

  20. Cardiac morbidity in an HIV-1 lipodystrophy patient cohort expressing the TNF-α-238 G/A single nucleotide gene polymorphism.

    Science.gov (United States)

    Mahajan, Supriya D; Gaekwad, Asmita; Pawar, Jyoti; Tripathy, Srikanth; Ghate, Manisha; Bhattacharya, Jayanta; Singh, Hari Om; Schwartz, Stanley A; Paranjape, Ramesh; Gangakhedkar, Raman

    2015-01-01

    In the current study we investigated the prevalence of the TNF-α 238G/A single nucleotide polymorphism (SNP) of the TNF-α gene in the development of lipodystrophy among HIV-1 infected individuals who had been receiving antiretroviral therapy (ART) in the immunodeficiency clinics of the National AIDS Research Institute (NARI) at Pune, India. We assessed the association of this SNP with the development of lipoatrophy/dyslipidemia and insulin resistance in these patients and measured carotid intima thickening which is a surrogate marker for chronic cardiac morbidity. Our results show that the incidence of the TNF-α 238G/A SNP is ~ two fold higher in patients with lipodystrophy as compared to those without lipodystrophy. Patients with lipodystrophy demonstrated a higher likelihood of the development of metabolic syndrome as evident by increased insulin sensitivity and increased percentage (%) β cell function. Further, a significant increase in left carotid intima thickness was observed in patients with lipodystrophy. Our study validates the association of the TNF-α 238G/A SNP allelic variant with the development of HIV- lipodystrophy via the modulation of TNF-α production, which contributes to dyslipidemia, increased lipolysis, increased insulin resistance, altered differentiation of adipocytes and increased carotid intima thickness. The contribution of genetic determinants such as the TNF-α 238G/A SNP to lipodystrophy, may provide insight into the mechanisms that underlie this disease condition and may be useful in the future for personalized therapy. Additionally, these findings will be useful in monitoring chronic cardiac morbidities among HIV infected individuals who express this SNP.

  1. TIM-family proteins inhibit HIV-1 release.

    Science.gov (United States)

    Li, Minghua; Ablan, Sherimay D; Miao, Chunhui; Zheng, Yi-Min; Fuller, Matthew S; Rennert, Paul D; Maury, Wendy; Johnson, Marc C; Freed, Eric O; Liu, Shan-Lu

    2014-09-02

    Accumulating evidence indicates that T-cell immunoglobulin (Ig) and mucin domain (TIM) proteins play critical roles in viral infections. Herein, we report that the TIM-family proteins strongly inhibit HIV-1 release, resulting in diminished viral production and replication. Expression of TIM-1 causes HIV-1 Gag and mature viral particles to accumulate on the plasma membrane. Mutation of the phosphatidylserine (PS) binding sites of TIM-1 abolishes its ability to block HIV-1 release. TIM-1, but to a much lesser extent PS-binding deficient mutants, induces PS flipping onto the cell surface; TIM-1 is also found to be incorporated into HIV-1 virions. Importantly, TIM-1 inhibits HIV-1 replication in CD4-positive Jurkat cells, despite its capability of up-regulating CD4 and promoting HIV-1 entry. In addition to TIM-1, TIM-3 and TIM-4 also block the release of HIV-1, as well as that of murine leukemia virus (MLV) and Ebola virus (EBOV); knockdown of TIM-3 in differentiated monocyte-derived macrophages (MDMs) enhances HIV-1 production. The inhibitory effects of TIM-family proteins on virus release are extended to other PS receptors, such as Axl and RAGE. Overall, our study uncovers a novel ability of TIM-family proteins to block the release of HIV-1 and other viruses by interaction with virion- and cell-associated PS. Our work provides new insights into a virus-cell interaction that is mediated by TIMs and PS receptors.

  2. HIV-1CRF07_BC毒株gp41NHR结构域N51的表达及结构分析%Expression, structure and antigenicity analysis of N51 derived from the N-terminal heptad repeat domain in gp41 of HIV-1 CRF07_BC strain

    Institute of Scientific and Technical Information of China (English)

    邵继平; 姜世勃; 刘叔文

    2012-01-01

    Objective To express N51 derived from the N-terminal heptad repeat (NHR) domain in gp41 of the HIV-1 CRF07_BC strain and analyze its molecular structure and antigenicity. Methods Overlapping PCR was used to amplify the DNA fragment encoding N51Fd gene, which was then subcloned into the vector pFUSE-hIgGl-Fc2. The construct was confirmed by DNA sequencing. The structure and antigenicity of the recombinant protein N51FdFc-BC were analyzed using bioinformatic software, circular dichroism, and Western blotting. Results A recombinant expression vector pFUSE/N51Fd-BC was successfully constructed. N51FdFc-BC recombinant protein with a relative molecular mass of about 35 000 was effectively expressed in mammalian 293T cells and could be recognized by rabbit antibodies against HIV-1 gp41 N/C peptides as shown by Western blotting. Bioinformatic analysis showed that the recombinant protein N51FdFc-BC, with a relative molecular mass of 34 315.1 and a PI of 7.59, formed a secondary structure of random coil to allow its interactions as an antigen with antibodies. Circular dichroism measurement confirmed the random coil structure of N51FdFc-BC protein. Conclusion The recombinant protein N51FdFc-BC has a random coil structure and can be used as an immunogen for development of HIV-1 subunit vaccine.%目的 对来源于HIV-1中国流行株CRF07 BC的包膜糖蛋白gp41 NHR结构域的N51进行表达和结构及抗原性分析.方法 运用重叠延伸PCR方法扩增出N51Fd基因,将其插入真核表达载体pFUSE-hIgG1-Fc2,并进行核苷酸序列测定.利用生物信息学软件、圆二色谱法、免疫印迹法对表达的N51FdFc-BC重组蛋白进行结构和抗原性分析.结果 成功构建pFUSE/N51Fd-BC表达载体,并在真核表达体系实现了目的蛋白的高效表达.免疫印迹结果显示该重组蛋白大小约为35 000,可与抗HIV-1 gp41 N/C多肽的抗体反应.生物信息学分析显示N51 FdFc-BC重组蛋白相对分子质量为34 315.1,等电点PI为7

  3. During Stably Suppressive Antiretroviral Therapy Integrated HIV-1 DNA Load in Peripheral Blood is Associated with the Frequency of CD8 Cells Expressing HLA-DR/DP/DQ

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    Alessandra Ruggiero

    2015-09-01

    Conclusions: The observed positive association between integrated HIV-1 DNA load and frequency of CD8+DR/DP/DQ+ cells indicates that a close correlation between HIV persistence and immune activation continues during consistently suppressive therapy. The inducers of the distinct activation profile warrant further investigation.

  4. An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression.

    Science.gov (United States)

    Darcis, Gilles; Kula, Anna; Bouchat, Sophie; Fujinaga, Koh; Corazza, Francis; Ait-Ammar, Amina; Delacourt, Nadège; Melard, Adeline; Kabeya, Kabamba; Vanhulle, Caroline; Van Driessche, Benoit; Gatot, Jean-Stéphane; Cherrier, Thomas; Pianowski, Luiz F; Gama, Lucio; Schwartz, Christian; Vila, Jorge; Burny, Arsène; Clumeck, Nathan; Moutschen, Michel; De Wit, Stéphane; Peterlin, B Matija; Rouzioux, Christine; Rohr, Olivier; Van Lint, Carine

    2015-07-01

    The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART) is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET) bromodomain inhibitors (BETi) are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb)-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC) agonists (prostratin, bryostatin-1 and ingenol-B), which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151)). Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs) and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA combinations

  5. An In-Depth Comparison of Latency-Reversing Agent Combinations in Various In Vitro and Ex Vivo HIV-1 Latency Models Identified Bryostatin-1+JQ1 and Ingenol-B+JQ1 to Potently Reactivate Viral Gene Expression.

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    Gilles Darcis

    2015-07-01

    Full Text Available The persistence of latently infected cells in patients under combinatory antiretroviral therapy (cART is a major hurdle to HIV-1 eradication. Strategies to purge these reservoirs are needed and activation of viral gene expression in latently infected cells is one promising strategy. Bromodomain and Extraterminal (BET bromodomain inhibitors (BETi are compounds able to reactivate latent proviruses in a positive transcription elongation factor b (P-TEFb-dependent manner. In this study, we tested the reactivation potential of protein kinase C (PKC agonists (prostratin, bryostatin-1 and ingenol-B, which are known to activate NF-κB signaling pathway as well as P-TEFb, used alone or in combination with P-TEFb-releasing agents (HMBA and BETi (JQ1, I-BET, I-BET151. Using in vitro HIV-1 post-integration latency model cell lines of T-lymphoid and myeloid lineages, we demonstrated that PKC agonists and P-TEFb-releasing agents alone acted as potent latency-reversing agents (LRAs and that their combinations led to synergistic activation of HIV-1 expression at the viral mRNA and protein levels. Mechanistically, combined treatments led to higher activations of P-TEFb and NF-κB than the corresponding individual drug treatments. Importantly, we observed in ex vivo cultures of CD8+-depleted PBMCs from 35 cART-treated HIV-1+ aviremic patients that the percentage of reactivated cultures following combinatory bryostatin-1+JQ1 treatment was identical to the percentage observed with anti-CD3+anti-CD28 antibodies positive control stimulation. Remarkably, in ex vivo cultures of resting CD4+ T cells isolated from 15 HIV-1+ cART-treated aviremic patients, the combinations bryostatin-1+JQ1 and ingenol-B+JQ1 released infectious viruses to levels similar to that obtained with the positive control stimulation. The potent effects of these two combination treatments were already detected 24 hours post-stimulation. These results constitute the first demonstration of LRA

  6. Iron(II) supramolecular helicates interfere with the HIV-1 Tat–TAR RNA interaction critical for viral replication

    Science.gov (United States)

    Malina, Jaroslav; Hannon, Michael J.; Brabec, Viktor

    2016-07-01

    The interaction between the HIV-1 transactivator protein Tat and TAR (transactivation responsive region) RNA, plays a critical role in HIV-1 transcription. Iron(II) supramolecular helicates were evaluated for their in vitro activity to inhibit Tat–TAR RNA interaction using UV melting studies, electrophoretic mobility shift assay, and RNase A footprinting. The results demonstrate that iron(II) supramolecular helicates inhibit Tat-TAR interaction at nanomolar concentrations by binding to TAR RNA. These studies provide a new insight into the biological potential of metallosupramolecular helicates.

  7. Drug 9AA reactivates p21/Waf1 and Inhibits HIV-1 progeny formation

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    Dubrovsky Larisa

    2008-03-01

    Full Text Available Abstract It has been demonstrated that the p53 pathway plays an important role in HIV-1 infection. Previous work from our lab has established a model demonstrating how p53 could become inactivated in HIV-1 infected cells through binding to Tat. Subsequently, p53 was inactivated and lost its ability to transactivate its downstream target gene p21/waf1. P21/waf1 is a well-known cdk inhibitor (CKI that can lead to cell cycle arrest upon DNA damage. Most recently, the p21/waf1 function was further investigated as a molecular barrier for HIV-1 infection of stem cells. Therefore, we reason that the restoration of the p53 and p21/waf1 pathways could be a possible theraputical arsenal for combating HIV-1 infection. In this current study, we show that a small chemical molecule, 9-aminoacridine (9AA at low concentrations, could efficiently reactivate p53 pathway and thereby restoring the p21/waf1 function. Further, we show that the 9AA could significantly inhibit virus replication in activated PBMCs, likely through a mechanism of inhibiting the viral replication machinery. A mechanism study reveals that the phosphorylated p53ser15 may be dissociated from binding to HIV-1 Tat protein, thereby activating the p21/waf1 gene. Finally, we also show that the 9AA-activated p21/waf1 is recruited to HIV-1 preintegration complex, through a mechanism yet to be elucidated.

  8. Expression and purification of BDNF-TAT fusion protein in E.coli and its distribution in brain%BDNF-TAT融合蛋白在大肠杆菌中的表达纯化及脑中分布

    Institute of Scientific and Technical Information of China (English)

    罗道飞; 李文适; 陈姗; 季爱民

    2011-01-01

    目的 在大肠杆菌中表达并纯化BDNF-TAT融合蛋白,研究其靶向性及在脑中的分布.方法 重组质粒PET-30(a)-BDNF-TAT转染至大肠杆菌BL21(DE3)pLysS中,IPTG诱导其表达后用SP-Sepharose阳离子交换柱纯化,纯化后蛋白用0.4 mol/L精氨酸倍比稀释法复性.KM种小鼠采用随机数字表法分为给药组[尾静脉注射复性后BDNF-TAT融合蛋白4 μg(适量生理盐水溶解)]、阴性对照组(尾静脉注射等体积生理盐水)和空白对照组(不进行任何处理),每组各3只.3 h后提取小鼠脑组织全蛋白,Western blotting检测脑组织中BDNF-TAT表达,SABC免疫组化染色观察BDNF-TAT在脑组织中的分布.结果 获得纯度约90%活性的BDNF-TAT融合蛋白.给药组BDNF-TAT蛋白的相对表达最为1.897±0.286,阴性对照组BDNF-TAT蛋白的相对表达量为0.615±0.234,空白对照组BDNF-TAT蛋白的相对表达量为0.335±0.154,比较差异有统计学意义(F=39.019,P=0.0000).免疫组化染色结果显示给药组BDNF-TAT主要分布于小鼠脑组织海马CA1、CA3和DG区,而阴性对照组和空白对照组巾没有明显阳性染色.结论 BDNF-TAT融合蛋白在大肠杆菌中以包涵体形式大量表达,并能通过外周给药靶向至小鼠脑组织.%Objective To explore the expression and purification of BDNF-TAT fusion protein in E.coli, and study its brain-targeting and distribution in brain. Methods Plasmid PET-30(a) -BDNF-TAT was transfected into the E.coli BL21 (DE3)pLysS;the expression of PET-30(a)-BDNF-TAT was induced by isopropyl-beta-d-thiogalactopyranoside (IPTG);this BDNF-TAT fusion protein was purified by SP-Sepharose cation exchange column and then renatured by 0.4 mol/L arginine. According to the random number table method, KM mice were divided into 3 groups: BDNF-TAT treatment group (giving 4 μg BDNF-TAT through intravenous injection, n=3), negative control group (giving same volume of saline through intravenous injection, n=3) and blank control group

  9. Systematic Analysis of the Functions of Lysine Acetylation in the Regulation of Tat Activity.

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    Minghao He

    Full Text Available The Tat protein of HIV-1 has several well-known properties, such as nucleocytoplasmic trafficking, transactivation of transcription, interaction with tubulin, regulation of mitotic progression, and induction of apoptosis. Previous studies have identified a couple of lysine residues in Tat that are essential for its functions. In order to analyze the functions of all the lysine residues in Tat, we mutated them individually to alanine, glutamine, and arginine. Through systematic analysis of the lysine mutants, we discovered several previously unidentified characteristics of Tat. We found that lysine acetylation could modulate the subcellular localization of Tat, in addition to the regulation of its transactivation activity. Our data also revealed that lysine mutations had distinct effects on microtubule assembly and Tat binding to bromodomain proteins. By correlation analysis, we further found that the effects of Tat on apoptosis and mitotic progression were not entirely attributed to its effect on microtubule assembly. Our findings suggest that Tat may regulate diverse cellular activities through binding to different proteins and that the acetylation of distinct lysine residues in Tat may modulate its interaction with various partners.

  10. HIV-1 Vif adaptation to human APOBEC3H haplotypes.

    Science.gov (United States)

    Ooms, Marcel; Brayton, Bonnie; Letko, Michael; Maio, Susan M; Pilcher, Christopher D; Hecht, Frederick M; Barbour, Jason D; Simon, Viviana

    2013-10-16

    Several human APOBEC3 deaminases can inhibit HIV-1 replication in vitro. HIV-1 Vif counteracts this restriction by targeting APOBEC3 for proteasomal degradation. Human APOBEC3H (A3H) is highly polymorphic, with natural variants differing considerably in anti-HIV-1 activity in vitro. To examine HIV-1 adaptation to variation in A3H activity in a natural infection context, we determined the A3H haplotypes and Vif sequences from 76 recently infected HIV-1 patients. We detected A3H-specific Vif changes suggesting viral adaptation. The patient-derived Vif sequences were used to engineer viruses that specifically differed in their ability to counteract A3H. Replication of these Vif-variant viruses in primary T cells naturally expressing active or inactive A3H haplotypes showed that endogenously expressed A3H restricts HIV-1 replication. Proviral DNA from A3H-restricted viruses showed high levels of G-to-A mutations in an A3H-specific GA dinucleotide context. Taken together, our data validate A3H expressed at endogenous levels as a bona fide HIV-1 restriction factor.

  11. Necroptosis takes place in human immunodeficiency virus type-1 (HIV-1-infected CD4+ T lymphocytes.

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    Ting Pan

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection is characterized by progressive depletion of CD4+ T lymphocytes and dysfunction of the immune system. The numbers of CD4+ T lymphocytes in the human body are maintained constantly by homeostatic mechanisms that failed during HIV-1 infection, resulting in progressive loss of CD4+ T cells mainly via apoptosis. Recently, a non-apoptotic form of necrotic programmed cell death, named necroptosis, has been investigated in many biological and pathological processes. We then determine whether HIV-1-infected cells also undergo necroptosis. In this report, we demonstrate that HIV-1 not only induces apoptosis, but also mediates necroptosis in the infected primary CD4+ T lymphocytes and CD4+ T-cell lines. Necroptosis-dependent cytopathic effects are significantly increased in HIV-1-infected Jurkat cells that is lack of Fas-associated protein-containing death domain (FADD, indicating that necroptosis occurs as an alternative cell death mechanism in the absence of apoptosis. Unlike apoptosis, necroptosis mainly occurs in HIV-infected cells and spares bystander damage. Treatment with necrostatin-1(Nec-1, a RIP1 inhibitor that specifically blocks the necroptosis pathway, potently restrains HIV-1-induced cytopathic effect and interestingly, inhibits the formation of HIV-induced syncytia in CD4+ T-cell lines. This suggests that syncytia formation is mediated, at least partially, by necroptosis-related processes. Furthermore, we also found that the HIV-1 infection-augmented tumor necrosis factor-alpha (TNF-α plays a key role in inducing necroptosis and HIV-1 Envelope and Tat proteins function as its co-factors. Taken together,necroptosis can function as an alternative cell death pathway in lieu of apoptosis during HIV-1 infection, thereby also contributing to HIV-1-induced cytopathic effects. Our results reveal that in addition to apoptosis, necroptosis also plays an important role in HIV-1-induced pathogenesis.

  12. HIV-1 integrase modulates the interaction of the HIV-1 cellular cofactor LEDGF/p75 with chromatin

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    Garcia-Rivera Jose A

    2011-04-01

    Full Text Available Abstract Background Chromatin binding plays a central role in the molecular mechanism of LEDGF/p75 in HIV-1 DNA integration. Conflicting results have been reported in regards to the relevance of the LEDGF/p75 chromatin binding element PWWP domain in its HIV-1 cofactor activity. Results Here we present evidence that re-expression of a LEDGF/p75 mutant lacking the PWWP domain (ΔPWWP rescued HIV-1 infection in cells verified to express background levels of endogenous LEDGF/p75 that do not support efficient HIV-1 infection. The HIV-1 cofactor activity of LEDGF/p75 ΔPWWP was similar to that of LEDGF/p75 wild type (WT. A possible molecular explanation for the nonessential role of PWWP domain in the HIV-1 cofactor activity of LEDGF/p75 comes from the fact that coexpression of HIV-1 integrase significantly restored the impaired chromatin binding activity of LEDGF/p75 ΔPWWP. However, integrase failed to promote chromatin binding of a non-chromatin bound LEDGF/p75 mutant that lacks both the PWWP domain and the AT hook motifs (ΔPWWP/AT and that exhibits negligible HIV-1 cofactor activity. The effect of integrase on the chromatin binding of LEDGF/p75 requires the direct interaction of these two proteins. An HIV-1 integrase mutant, unable to interact with LEDGF/p75, failed to enhance chromatin binding, whereas integrase wild type did not increase the chromatin binding strength of a LEDGF/p75 mutant lacking the integrase binding domain (ΔIBD. Conclusions Our data reveal that the PWWP domain of LEDGF/p75 is not essential for its HIV-1 cofactor activity, possibly due to an integrase-mediated increase of the chromatin binding strength of this LEDGF/p75 mutant.

  13. HIV-1 integrase modulates the interaction of the HIV-1 cellular cofactor LEDGF/p75 with chromatin.

    Science.gov (United States)

    Astiazaran, Paulina; Bueno, Murilo Td; Morales, Elisa; Kugelman, Jeffrey R; Garcia-Rivera, Jose A; Llano, Manuel

    2011-04-21

    Chromatin binding plays a central role in the molecular mechanism of LEDGF/p75 in HIV-1 DNA integration. Conflicting results have been reported in regards to the relevance of the LEDGF/p75 chromatin binding element PWWP domain in its HIV-1 cofactor activity. Here we present evidence that re-expression of a LEDGF/p75 mutant lacking the PWWP domain (ΔPWWP) rescued HIV-1 infection in cells verified to express background levels of endogenous LEDGF/p75 that do not support efficient HIV-1 infection. The HIV-1 cofactor activity of LEDGF/p75 ΔPWWP was similar to that of LEDGF/p75 wild type (WT). A possible molecular explanation for the nonessential role of PWWP domain in the HIV-1 cofactor activity of LEDGF/p75 comes from the fact that coexpression of HIV-1 integrase significantly restored the impaired chromatin binding activity of LEDGF/p75 ΔPWWP. However, integrase failed to promote chromatin binding of a non-chromatin bound LEDGF/p75 mutant that lacks both the PWWP domain and the AT hook motifs (ΔPWWP/AT) and that exhibits negligible HIV-1 cofactor activity. The effect of integrase on the chromatin binding of LEDGF/p75 requires the direct interaction of these two proteins. An HIV-1 integrase mutant, unable to interact with LEDGF/p75, failed to enhance chromatin binding, whereas integrase wild type did not increase the chromatin binding strength of a LEDGF/p75 mutant lacking the integrase binding domain (ΔIBD). Our data reveal that the PWWP domain of LEDGF/p75 is not essential for its HIV-1 cofactor activity, possibly due to an integrase-mediated increase of the chromatin binding strength of this LEDGF/p75 mutant.

  14. FACT Proteins, SUPT16H and SSRP1, Are Transcriptional Suppressors of HIV-1 and HTLV-1 That Facilitate Viral Latency*

    Science.gov (United States)

    Huang, Huachao; Santoso, Netty; Power, Derek; Simpson, Sydney; Dieringer, Michael; Miao, Hongyu; Gurova, Katerina; Giam, Chou-Zen; Elledge, Stephen J.; Zhu, Jian

    2015-01-01

    Our functional genomic RNAi screens have identified the protein components of the FACT (facilitates chromatin transcription) complex, SUPT16H and SSRP1, as top host factors that negatively regulate HIV-1 replication. FACT interacts specifically with histones H2A/H2B to affect assembly and disassembly of nucleosomes, as well as transcription elongation. We further investigated the suppressive role of FACT proteins in HIV-1 transcription. First, depletion of SUPT16H or SSRP1 protein enhances Tat-mediated HIV-1 LTR (long terminal repeat) promoter activity. Second, HIV-1 Tat interacts with SUPT16H but not SSRP1 protein. However, both SUPT16H and SSRP1 are recruited to LTR promoter. Third, the presence of SUPT16H interferes with the association of Cyclin T1 (CCNT1), a subunit of P-TEFb, with the Tat-LTR axis. Removing inhibitory mechanisms to permit HIV-1 transcription is an initial and key regulatory step to reverse post-integrated latent HIV-1 proviruses for purging of reservoir cells. We therefore evaluated the role of FACT proteins in HIV-1 latency and reactivation. Depletion of SUPT16H or SSRP1 protein affects both HIV-1 transcriptional initiation and elongation and spontaneously reverses latent HIV-1 in U1/HIV and J-LAT cells. Similar effects were observed with a primary CD4+ T cell model of HIV-1 latency. FACT proteins also interfere with HTLV-1 Tax-LTR-mediated transcription and viral latency, indicating that they may act as general transcriptional suppressors for retroviruses. We conclude that FACT proteins SUPT16H and SSRP1 play a key role in suppressing HIV-1 transcription and promoting viral latency, which may serve as promising gene targets for developing novel HIV-1 latency-reversing agents. PMID:26378236

  15. HIV-1 subtypes in Yugoslavia.

    Science.gov (United States)

    Stanojevic, Maja; Papa, Anna; Papadimitriou, Evagelia; Zerjav, Sonja; Jevtovic, Djordje; Salemovic, Dubravka; Jovanovic, Tanja; Antoniadis, Antonis

    2002-05-01

    To gain insight concerning the genetic diversity of HIV-1 viruses associated with the HIV-1 epidemic in Yugoslavia, 45 specimens from HIV-1-infected individuals were classified into subtypes by sequence-based phylogenetic analysis of the polymerase (pol) region of the viral genome. Forty-one of 45 specimens (91.2%) were identified as pol subtype B, 2 of 45 as subtype C (4.4%), 1 of 45 as CRF01_AE (2.2%), and 1 as CRF02_AG recombinant (2.2%). Nucleotide divergence among subtype B sequences was 4.8%. Results of this study show that among HIV-1-infected patients in Yugoslavia subtype B predominates (91.5%), whereas non-B subtypes are present at a low percentage, mostly related to travel abroad.

  16. HIV-1 activates macrophages independent of Toll-like receptors.

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    Joseph N Brown

    Full Text Available BACKGROUND: Macrophages provide an interface between innate and adaptive immunity and are important long-lived reservoirs for Human Immunodeficiency Virus Type-1 (HIV-1. Multiple genetic networks involved in regulating signal transduction cascades and immune responses in macrophages are coordinately modulated by HIV-1 infection. METHODOLOGY/PRINCIPAL FINDINGS: To evaluate complex interrelated processes and to assemble an integrated view of activated signaling networks, a systems biology strategy was applied to genomic and proteomic responses by primary human macrophages over the course of HIV-1 infection. Macrophage responses, including cell cycle, calcium, apoptosis, mitogen-activated protein kinases (MAPK, and cytokines/chemokines, to HIV-1 were temporally regulated, in the absence of cell proliferation. In contrast, Toll-like receptor (TLR pathways remained unaltered by HIV-1, although TLRs 3, 4, 7, and 8 were expressed and responded to ligand stimulation in macrophages. HIV-1 failed to activate phosphorylation of IRAK-1 or IRF-3, modulate intracellular protein levels of Mx1, an interferon-stimulated gene, or stimulate secretion of TNF, IL-1beta, or IL-6. Activation of pathways other than TLR was inadequate to stimulate, via cross-talk mechanisms through molecular hubs, the production of proinflammatory cytokines typical of a TLR response. HIV-1 sensitized macrophage responses to TLR ligands, and the magnitude of viral priming was related to virus replication. CONCLUSIONS/SIGNIFICANCE: HIV-1 induced a primed, proinflammatory state, M1(HIV, which increased the responsiveness of macrophages to TLR ligands. HIV-1 might passively evade pattern recognition, actively inhibit or suppress recognition and signaling, or require dynamic interactions between macrophages and other cells, such as lymphocytes or endothelial cells. HIV-1 evasion of TLR recognition and simultaneous priming of macrophages may represent a strategy for viral survival, contribute

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

    Science.gov (United States)

    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.

  18. Sequence and structure requirements for specific recognition of HIV-1 TAR and DIS RNA by the HIV-1 Vif protein.

    Science.gov (United States)

    Freisz, Séverine; Mezher, Joelle; Hafirassou, Lamine; Wolff, Philippe; Nominé, Yves; Romier, Christophe; Dumas, Philippe; Ennifar, Eric

    2012-07-01

    The HIV-1 Vif protein plays an essential role in the regulation of the infectivity of HIV-1 virion and in vivo pathogenesis. Vif neutralizes the human DNA-editing enzyme APOBEC3 protein, an antiretroviral cellular factor from the innate immune system, allowing the virus to escape the host defence system. It was shown that Vif is packaged into viral particles through specific interactions with the viral genomic RNA. Conserved and structured sequences from the 5'-noncoding region, such as the Tat-responsive element (TAR) or the genomic RNA dimerization initiation site (DIS), are primary binding sites for Vif. In the present study we used isothermal titration calorimetry to investigate sequence and structure determinants important for Vif binding to short viral RNA corresponding to TAR and DIS stem-loops. We showed that Vif specifically binds TAR and DIS in the low nanomolar range. In addition, Vif primarily binds the TAR UCU bulge, but not the apical loop. Determinants for Vif binding to the DIS loop-loop complex are likely more complex and involve the self-complementary loop together with the upper part of the stem. These results suggest that Tat-TAR inhibitors or DIS small molecule binders might be also effective to disturb Vif-TAR and Vif-DIS binding in order to reduce Vif packaging into virions.

  19. NKT cells in HIV-1 infection

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Natural killer T (NKT) cells are a unique T cell population that have important immunoregulatory functions and have been shown to be involved in host immunity against a range of microorganisms. It also emerges that they might play a role in HIV-1 infection, and therefore be selectively depleted during the early stages of infection. Recent studies are reviewed regarding the dynamics of NKT depletion during HIV-I infection and their recovery under highly active antiretrovirai treatment (HAART). Possible mechanisms for these changes are proposed based on the recent developments in HIV pathogenesis. Further discussions are focused on HIV's disruption of NKT activation by downregulating CDId expression on antigen presentation cells (APC). HIV-1 protein Nefis found to play the major role by interrupting the intraceilular trafficking of nascent and recycling CDId molecules.

  20. Prediction of HIV-1 virus-host protein interactions using virus and host sequence motifs

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    Tozeren Aydin

    2009-05-01

    Full Text Available Abstract Background Host protein-protein interaction networks are altered by invading virus proteins, which create new interactions, and modify or destroy others. The resulting network topology favors excessive amounts of virus production in a stressed host cell network. Short linear peptide motifs common to both virus and host provide the basis for host network modification. Methods We focused our host-pathogen study on the binding and competing interactions of HIV-1 and human proteins. We showed that peptide motifs conserved across 70% of HIV-1 subtype B and C samples occurred in similar positions on HIV-1 proteins, and we documented protein domains that interact with these conserved motifs. We predicted which human proteins may be targeted by HIV-1 by taking pairs of human proteins that may interact via a motif conserved in HIV-1 and the corresponding interacting protein domain. Results Our predictions were enriched with host proteins known to interact with HIV-1 proteins ENV, NEF, and TAT (p-value Conclusion A list of host proteins highly enriched with those targeted by HIV-1 proteins can be obtained by searching for host protein motifs along virus protein sequences. The resulting set of host proteins predicted to be targeted by virus proteins will become more accurate with better annotations of motifs and domains. Nevertheless, our study validates the role of linear binding motifs shared by virus and host proteins as an important part of the crosstalk between virus and host.

  1. Transplanting supersites of HIV-1 vulnerability.

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    Tongqing Zhou

    Full Text Available One strategy for isolating or eliciting antibodies against a specific target region on the envelope glycoprotein trimer (Env of the human immunodeficiency virus type 1 (HIV-1 involves the creation of site transplants, which present the target region on a heterologous protein scaffold with preserved antibody-binding properties. If the target region is a supersite of HIV-1 vulnerability, recognized by a collection of broadly neutralizing antibodies, this strategy affords the creation of "supersite transplants", capable of binding (and potentially eliciting antibodies similar to the template collection of effective antibodies. Here we transplant three supersites of HIV-1 vulnerability, each targeted by effective neutralizing antibodies from multiple donors. To implement our strategy, we chose a single representative antibody against each of the target supersites: antibody 10E8, which recognizes the membrane-proximal external region (MPER on the HIV-1 gp41 glycoprotein; antibody PG9, which recognizes variable regions one and two (V1V2 on the HIV-1 gp120 glycoprotein; and antibody PGT128 which recognizes a glycopeptide supersite in variable region 3 (glycan V3 on gp120. We used a structural alignment algorithm to identify suitable acceptor proteins, and then designed, expressed, and tested antigenically over 100-supersite transplants in a 96-well microtiter-plate format. The majority of the supersite transplants failed to maintain the antigenic properties of their respective template supersite. However, seven of the glycan V3-supersite transplants exhibited nanomolar affinity to effective neutralizing antibodies from at least three donors and recapitulated the mannose9-N-linked glycan requirement of the template supersite. The binding of these transplants could be further enhanced by placement into self-assembling nanoparticles. Essential elements of the glycan V3 supersite, embodied by as few as 3 N-linked glycans and ∼ 25 Env residues, can be

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

    Science.gov (United States)

    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. DBR1 siRNA inhibition of HIV-1 replication

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    Naidu Yathi

    2005-10-01

    Full Text Available Abstract Background HIV-1 and all retroviruses are related to retroelements of simpler organisms such as the yeast Ty elements. Recent work has suggested that the yeast retroelement Ty1 replicates via an unexpected RNA lariat intermediate in cDNA synthesis. The putative genomic RNA lariat intermediate is formed by a 2'-5' phosphodiester bond, like that found in pre-mRNA intron lariats and it facilitates the minus-strand template switch during cDNA synthesis. We hypothesized that HIV-1 might also form a genomic RNA lariat and therefore that siRNA-mediated inhibition of expression of the human RNA lariat de-branching enzyme (DBR1 expression would specifically inhibit HIV-1 replication. Results We designed three short interfering RNA (siRNA molecules targeting DBR1, which were capable of reducing DBR1 mRNA expression by 80% and did not significantly affect cell viability. We assessed HIV-1 replication in the presence of DBR1 siRNA and found that DBR1 knockdown led to decreases in viral cDNA and protein production. These effects could be reversed by cotransfection of a DBR1 cDNA indicating that the inhibition of HIV-1 replication was a specific effect of DBR1 underexpression. Conclusion These data suggest that DBR1 function may be needed to debranch a putative HIV-1 genomic RNA lariat prior to completion of reverse transcription.

  4. HTLV-1/-2 and HIV-1 Co-infections: Retroviral Interference On Host Immune Status

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    Elisabetta ePilotti

    2013-12-01

    Full Text Available The human retroviruses HIV-1 and HTLV-1/HTLV-2 share similar routes of transmission but cause significantly different diseases. In this review we have outlined the immune mediated mechanisms by which HTLVs affect HIV-1 disease in co-infected hosts. During co-infection with HIV-1, HTLV-2 modulates the cellular microenvironment favoring its own viability and inhibiting HIV-1 progression. This is achieved when the HTLV-2 proviral load is higher than that of HIV-1, and thanks to the ability of HTLV-2 to: i up-regulate viral suppressive CCL3L1 chemokine expression; ii overcome HIV-1 capacity to activate the JAK/STAT pathway; iii reduce the activation of T and NK cells; iv modulate the host miRNA profiles. These alterations of immune functions have been mainly attributed to the effects of the HTLV-2 regulatory protein Tax and suggest that HTLV-2 exerts a protective role against HIV-1 infection. Contrary to HIV-1/HTLV-2, the effect of HIV-1/HTLV-1 co-infection on immunological and pathological conditions is still controversial. There is evidence that indicate a worsening of HIV-1 infection, while other evidence does not show clinically relevant effects in HIV-positive people. Possible differences on innate immune mechanisms and a particularly impact on NK cells are becoming evident. The differences between the two HIV-1/HTLV-1 and HIV-1/HTLV-2 co-infections are highlighted and further discussed.

  5. Construction and infectivity analysis of live attenuated recombinant salmonella expressing HIV-1 447-52D epitope on fimbriae%以沙门氏菌菌毛为载体的重组HIV-1 447-52D表位疫苗的构建和毒力检测

    Institute of Scientific and Technical Information of China (English)

    金刚; 于璐; 岳超; 李海宁; 杨全; 李庆海; 刘树林

    2016-01-01

    Objective To construct recombinant attenuated Salmonella expressing the HIV-1 447-52D epitope on the thin aggregative fimbriae and to analyze the infectivity status of this recombinant strain.Methods The recombinant attenuated Salmonella ST-44752D was constructed by using pHSG415 gene replacement system to replace the wild-type agfA gene with the chimeric agfA:44752D gene and then verified by polymeruse chain reaction(PCR) and sequencing.The expression of the recombinant thin aggregative fimbriae was analyzed by Western blotting.Congo red binding test was performed to examine the adsorbability of fimbriae.50% lethal dose (LD50) and organ distribution status of the 447-52D strain were determined in mice.Results The 447-52D expressing recombinant strain was successfully constructed and confirmed by DNA sequencing.Compared with wild-type ST,recombinant ST-44752D strain showed similar expression level of the thin aggregative fimbriae AgfA,and similar binding activity to Congo red reagent.The LD50 value of ST-44752D strain in mice was 1.45 × 109 CFU.After infection,ST-44752D strain could distribute effectively in spleen and lymph node,similar to wild-type ST.Conclusion The recombinant attenuated Salmonella typhimurium ST-44752D harboring HIV-1 447-52D epitope on fimbriae was successfully constructed.The 447-52D epitope within AgfA did not influence AgfA expression,fimbrial adsorbability,bacterial LDS0 value or organ distribution in mice.%目的 构建菌毛上表达HIV-1 447-52D表位的减毒Salmonella typhimurium ST14028-3b aroA-44752D,并对其毒力进行检测.方法 利用同源重组技术,将447-52D表位整合至沙门氏菌细聚合菌毛上,Western blot检测其表达情况,通过刚果红结合实验分析外源表位对菌毛吸附能力的影响.感染动物后检测重组菌的毒力及其在小鼠体内的分布.结果 重组菌的嵌合基因片段测序结果和嵌合蛋白的表达分析表明,重组菌菌毛上成功表达外源447-52D表位.重

  6. A next-generation cleaved, soluble HIV-1 Env trimer, BG505 SOSIP.664 gp140, expresses multiple epitopes for broadly neutralizing but not non-neutralizing antibodies.

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    Rogier W Sanders

    2013-09-01

    Full Text Available A desirable but as yet unachieved property of a human immunodeficiency virus type 1 (HIV-1 vaccine candidate is the ability to induce broadly neutralizing antibodies (bNAbs. One approach to the problem is to create trimeric mimics of the native envelope glycoprotein (Env spike that expose as many bNAb epitopes as possible, while occluding those for non-neutralizing antibodies (non-NAbs. Here, we describe the design and properties of soluble, cleaved SOSIP.664 gp140 trimers based on the subtype A transmitted/founder strain, BG505. These trimers are highly stable, more so even than the corresponding gp120 monomer, as judged by differential scanning calorimetry. They are also homogenous and closely resemble native virus spikes when visualized by negative stain electron microscopy (EM. We used several techniques, including ELISA and surface plasmon resonance (SPR, to determine the relationship between the ability of monoclonal antibodies (MAbs to bind the soluble trimers and neutralize the corresponding virus. In general, the concordance was excellent, in that virtually all bNAbs against multiple neutralizing epitopes on HIV-1 Env were highly reactive with the BG505 SOSIP.664 gp140 trimers, including quaternary epitopes (CH01, PG9, PG16 and PGT145. Conversely, non-NAbs to the CD4-binding site, CD4-induced epitopes or gp41ECTO did not react with the trimers, even when their epitopes were present on simpler forms of Env (e.g. gp120 monomers or dissociated gp41 subunits. Three non-neutralizing MAbs to V3 epitopes did, however, react strongly with the trimers but only by ELISA, and not at all by SPR and to only a limited extent by EM. These new soluble trimers are useful for structural studies and are being assessed for their performance as immunogens.

  7. A HIV-Tat/C4-binding protein chimera encoded by a DNA vaccine is highly immunogenic and contains acute EcoHIV infection in mice

    Science.gov (United States)

    Tomusange, Khamis; Wijesundara, Danushka; Gummow, Jason; Garrod, Tamsin; Li, Yanrui; Gray, Lachlan; Churchill, Melissa; Grubor-Bauk, Branka; Gowans, Eric J.

    2016-01-01

    DNA vaccines are cost-effective to manufacture on a global scale and Tat-based DNA vaccines have yielded protective outcomes in preclinical and clinical models of human immunodeficiency virus (HIV), highlighting the potential of such vaccines. However, Tat-based DNA vaccines have been poorly immunogenic, and despite the administration of multiple doses and/or the addition of adjuvants, these vaccines are not in general use. In this study, we improved Tat immunogenicity by fusing it with the oligomerisation domain of a chimeric C4-binding protein (C4b-p), termed IMX313, resulting in Tat heptamerisation and linked Tat to the leader sequence of tissue plasminogen activator (TPA) to ensure that the bulk of heptamerised Tat is secreted. Mice vaccinated with secreted Tat fused to IMX313 (pVAX-sTat-IMX313) developed higher titres of Tat-specific serum IgG, mucosal sIgA and cell-mediated immune (CMI) responses, and showed superior control of EcoHIV infection, a surrogate murine HIV challenge model, compared with animals vaccinated with other test vaccines. Given the crucial contribution of Tat to HIV-1 pathogenesis and the precedent of Tat-based DNA vaccines in conferring some level of protection in animal models, we believe that the virologic control demonstrated with this novel multimerised Tat vaccine highlights the promise of this vaccine candidate for humans. PMID:27358023

  8. Cell-specific RNA aptamer against human CCR5 specifically targets HIV-1 susceptible cells and inhibits HIV-1 infectivity.

    Science.gov (United States)

    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.

  9. Opening of the TAR hairpin in the HIV-1 genome causes aberrant RNA dimerization and packaging

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    Das Atze T

    2012-07-01

    Full Text Available Abstract Background The TAR hairpin is present at both the 5′ and 3′ end of the HIV-1 RNA genome. The 5′ element binds the viral Tat protein and is essential for Tat-mediated activation of transcription. We recently observed that complete TAR deletion is allowed in the context of an HIV-1 variant that does not depend on this Tat-TAR axis for transcription. Mutations that open the 5′ stem-loop structure did however affect the leader RNA conformation and resulted in a severe replication defect. In this study, we set out to analyze which step of the HIV-1 replication cycle is affected by this conformational change of the leader RNA. Results We demonstrate that opening the 5′ TAR structure through a deletion in either side of the stem region caused aberrant dimerization and reduced packaging of the unspliced viral RNA genome. In contrast, truncation of the TAR hairpin through deletions in both sides of the stem did not affect RNA dimer formation and packaging. Conclusions These results demonstrate that, although the TAR hairpin is not essential for RNA dimerization and packaging, mutations in TAR can significantly affect these processes through misfolding of the relevant RNA signals.

  10. Increased iron export by ferroportin induces restriction of HIV-1 infection in sickle cell disease

    Science.gov (United States)

    Kumari, Namita; Ammosova, Tatiana; Diaz, Sharmin; Lin, Xionghao; Niu, Xiaomei; Ivanov, Andrey; Jerebtsova, Marina; Dhawan, Subhash; Oneal, Patricia; Nekhai, Sergei

    2017-01-01

    The low incidence of HIV-1 infection in patients with sickle cell disease (SCD) and inhibition of HIV-1 replication in vitro under the conditions of low intracellular iron or heme treatment suggests a potential restriction of HIV-1 infection in SCD. We investigated HIV-1 ex vivo infection of SCD peripheral blood mononuclear cells (PBMCs) and found that HIV-1 replication was inhibited at the level of reverse transcription (RT) and transcription. We observed increased expression of heme and iron-regulated genes, previously shown to inhibit HIV-1, including ferroportin, IKBα, HO-1, p21, and SAM domain and HD domain-containing protein 1 (SAMHD1). HIV-1 inhibition was less pronounced in hepcidin-treated SCD PBMCs and more pronounced in the iron or iron chelators treated, suggesting a key role of iron metabolism. In SCD PBMCs, labile iron levels were reduced and protein levels of ferroportin, HIF-1α, IKBα, and HO-1 were increased. Hemin treatment induced ferroportin expression and inhibited HIV-1 in THP-1 cells, mimicking the HIV-1 inhibition in SCD PBMCs, especially as hepcidin similarly prevented HIV-1 inhibition. In THP-1 cells with knocked down ferroportin, IKBα, or HO-1 genes but not HIF-1α or p21, HIV-1 was not inhibited by hemin. Activity of SAMHD1-regulatory CDK2 was decreased, and SAMHD1 phosphorylation was reduced in SCD PBMCs and hemin-treated THP-1 cells, suggesting SAMHD1-mediated HIV-1 restriction in SCD. Our findings point to ferroportin as a trigger of HIV-1 restriction in SCD settings, linking reduced intracellular iron levels to the inhibition of CDK2 activity, reduction of SAMHD1 phosphorylation, increased IKBα expression, and inhibition of HIV-1 RT and transcription.

  11. In vitro analysis of the TAT protein transduction domain as a drug delivery vehicle in protozoan parasites.

    Science.gov (United States)

    Chin Lee, Stephanie Hui; Jefferies, Ryan; Watt, Paul; Hopkins, Richard; Sotzik, Frank; Reid, Simon; Armson, Anthony; Boxell, Annika; Ryan, Una

    2008-03-01

    The present study was undertaken to analyse the capability of HIV-1 derived TAT protein transduction domain (PTD) fused with Green Fluorescent Protein (TAT-GFP) as a delivery vehicle into a range of protozoan parasites. Successful transduction of native purified TAT-GFP was observed by fluorescent microscopy in Cryptosporidium parvum, Giardia duodenalis, and Neospora caninum. The ability to transduce peptides and other cargo into protozoan parasites, will greatly assist in the delivery of future peptide-based drugs and target validation peptides.

  12. A suboptimal 5' splice site downstream of HIV-1 splice site A1 is required for unspliced viral mRNA accumulation and efficient virus replication

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    Stoltzfus C Martin

    2006-02-01

    Full Text Available Abstract Background Inefficient alternative splicing of the human immunodeficiency virus type 1(HIV-1 primary RNA transcript results in greater than half of all viral mRNA remaining unspliced. Regulation of HIV-1 alternative splicing occurs through the presence of suboptimal viral 5' and 3' splice sites (5' and 3'ss, which are positively regulated by exonic splicing enhancers (ESE and negatively regulated by exonic splicing silencers (ESS and intronic splicing silencers (ISS. We previously showed that splicing at HIV-1 3'ss A2 is repressed by ESSV and enhanced by the downstream 5'ss D3 signal. Disruption of ESSV results in increased vpr mRNA accumulation and exon 3 inclusion, decreased accumulation of unspliced viral mRNA, and decreased virus production. Results Here we show that optimization of the 5'ss D2 signal results in increased splicing at the upstream 3'ss A1, increased inclusion of exon 2 into viral mRNA, decreased accumulation of unspliced viral mRNA, and decreased virus production. Virus production from the 5'ss D2 and ESSV mutants was rescued by transient expression of HIV-1 Gag and Pol. We further show that the increased inclusion of either exon 2 or 3 does not significantly affect the stability of viral mRNA but does result in an increase and decrease, respectively, in HIV-1 mRNA levels. The changes in viral mRNA levels directly correlate with changes in tat mRNA levels observed upon increased inclusion of exon 2 or 3. Conclusion These results demonstrate that splicing at HIV-1 3'ss A1 is regulated by the strength of the downstream 5'ss signal and that suboptimal splicing at 3'ss A1 is necessary for virus replication. Furthermore, the replication defective phenotype resulting from increased splicing at 3'ss A1 is similar to the phenotype observed upon increased splicing at 3'ss A2. Further examination of the role of 5'ss D2 and D3 in the alternative splicing of 3'ss A1 and A2, respectively, is necessary to delineate a role for non

  13. HIV-1 assembly in macrophages

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    Benaroch Philippe

    2010-04-01

    Full Text Available Abstract The molecular mechanisms involved in the assembly of newly synthesized Human Immunodeficiency Virus (HIV particles are poorly understood. Most of the work on HIV-1 assembly has been performed in T cells in which viral particle budding and assembly take place at the plasma membrane. In contrast, few studies have been performed on macrophages, the other major target of HIV-1. Infected macrophages represent a viral reservoir and probably play a key role in HIV-1 physiopathology. Indeed macrophages retain infectious particles for long periods of time, keeping them protected from anti-viral immune response or drug treatments. Here, we present an overview of what is known about HIV-1 assembly in macrophages as compared to T lymphocytes or cell lines. Early electron microscopy studies suggested that viral assembly takes place at the limiting membrane of an intracellular compartment in macrophages and not at the plasma membrane as in T cells. This was first considered as a late endosomal compartment in which viral budding seems to be similar to the process of vesicle release into multi-vesicular bodies. This view was notably supported by a large body of evidence involving the ESCRT (Endosomal Sorting Complex Required for Transport machinery in HIV-1 budding, the observation of viral budding profiles in such compartments by immuno-electron microscopy, and the presence of late endosomal markers associated with macrophage-derived virions. However, this model needs to be revisited as recent data indicate that the viral compartment has a neutral pH and can be connected to the plasma membrane via very thin micro-channels. To date, the exact nature and biogenesis of the HIV assembly compartment in macrophages remains elusive. Many cellular proteins potentially involved in the late phases of HIV-1 cycle have been identified; and, recently, the list has grown rapidly with the publication of four independent genome-wide screens. However, their respective

  14. Identifying HIV-1 dual infections

    Directory of Open Access Journals (Sweden)

    Cornelissen Marion

    2007-09-01

    Full Text Available Abstract Transmission of human immunodeficiency virus (HIV is no exception to the phenomenon that a second, productive infection with another strain of the same virus is feasible. Experiments with RNA viruses have suggested that both coinfections (simultaneous infection with two strains of a virus and superinfections (second infection after a specific immune response to the first infecting strain has developed can result in increased fitness of the viral population. Concerns about dual infections with HIV are increasing. First, the frequent detection of superinfections seems to indicate that it will be difficult to develop a prophylactic vaccine. Second, HIV-1 superinfections have been associated with accelerated disease progression, although this is not true for all persons. In fact, superinfections have even been detected in persons controlling their HIV infections without antiretroviral therapy. Third, dual infections can give rise to recombinant viruses, which are increasingly found in the HIV-1 epidemic. Recombinants could have increased fitness over the parental strains, as in vitro models suggest, and could exhibit increased pathogenicity. Multiple drug resistant (MDR strains could recombine to produce a pan-resistant, transmittable virus. We will describe in this review what is presently known about super- and re-infection among ambient viral infections, as well as the first cases of HIV-1 superinfection, including HIV-1 triple infections. The clinical implications, the impact of the immune system, and the effect of anti-retroviral therapy will be covered, as will as the timing of HIV superinfection. The methods used to detect HIV-1 dual infections will be discussed in detail. To increase the likelihood of detecting a dual HIV-1 infection, pre-selection of patients can be done by serotyping, heteroduplex mobility assays (HMA, counting the degenerate base codes in the HIV-1 genotyping sequence, or surveying unexpected increases in the

  15. Unperturbed posttranscriptional regulatory Rev protein function and HIV-1 replication in astrocytes.

    Directory of Open Access Journals (Sweden)

    Ashok Chauhan

    Full Text Available Astrocytes protect neurons, but also evoke proinflammatory responses to injury and viral infections, including HIV. There is a prevailing notion that HIV-1 Rev protein function in astrocytes is perturbed, leading to restricted viral replication. In earlier studies, our finding of restricted viral entry into astrocytes led us to investigate whether there are any intracellular restrictions, including crippled Rev function, in astrocytes. Despite barely detectable levels of DDX3 (Rev-supporting RNA helicase and TRBP (anti-PKR in primary astrocytes compared to astrocytic cells, Rev function was unperturbed in wild-type, but not DDX3-ablated astrocytes. As in permissive cells, after HIV-1 entry bypass in astrocytes, viral-encoded Tat and Rev proteins had robust regulatory activities, leading to efficient viral replication. Productive HIV-1 infection in astrocytes persisted for several weeks. Our findings on HIV-1 entry bypass in astrocytes demonstrated that the intracellular environment is conducive to viral replication and that Tat and Rev functions are unperturbed.

  16. Comparison on virulence and immunogenicity of two recombinant vaccinia vaccines, Tian Tan and Guang9 strains, expressing the HIV-1 envelope gene.

    Science.gov (United States)

    Zhu, Rong; Huang, Weijin; Wang, Wenbo; Liu, Qiang; Nie, Jianhui; Meng, Shufang; Yu, Yongxin; Wang, Youchun

    2012-01-01

    The vaccinia virus Guang9 strain (VG9), derived from the vaccinia virus Tian Tan strain (VTT) has been found to be less virulent than VTT. To investigate whether VG9 could be a potential replicating virus vector, the TK genes in VG9 and VTT were replaced with the HIV-1 envelope gene via homologous recombination, resulting in the recombinant viruses, VG9-E and VTT-E. The biology, virulence, humoral and cellular immunological responses of VG9-E and VTT-E were evaluated. Our results indicated no obvious difference in range of host cells and diffusion between two recombinant viruses. Neurovirulence for VG9-E in weanling and suckling mice, and skin virulence in rabbits, were lower than that of VTT-E. The humoral immune responses, including binding antibody and neutralizing antibody responses, induced by VG9-E were not significantly different from those for VTT-E whilst IFN-γ response which represented cellular immune response induced by VG9-E was significantly higher than that did by VTT-E. Our results indicated that VG9-E was less virulent, yet induced higher cellular immune response than VTT-E. Therefore, it could be an ideal replicating vaccinia vector for HIV vaccine research and development.

  17. Epigenetic analysis of HIV-1 proviral genomes from infected individuals: predominance of unmethylated CpG's.

    Science.gov (United States)

    Weber, Stefanie; Weiser, Barbara; Kemal, Kimdar S; Burger, Harold; Ramirez, Christina M; Korn, Klaus; Anastos, Kathryn; Kaul, Rupert; Kovacs, Colin; Doerfler, Walter

    2014-01-20

    Efforts to cure HIV-1 infections aim at eliminating proviral DNA. Integrated DNA from various viruses often becomes methylated de novo and transcriptionally inactivated. We therefore investigated CpG methylation profiles of 55 of 94 CpG's (58.5%) in HIV-1 proviral genomes including ten CpG's in each LTR and additional CpG's in portions of gag, env, nef, rev, and tat genes. We analyzed 33 DNA samples from PBMC's of 23 subjects representing a broad spectrum of HIV-1 disease. In 22 of 23 HIV-1-infected individuals, there were only unmethylated CpG's regardless of infection status. In one long term nonprogressor, however, methylation of proviral DNA varied between 0 and 75% over an 11-year period although the CD4+ counts remained stable. Hence levels of proviral DNA methylation can fluctuate. The preponderance of unmethylated CpG's suggests that proviral methylation is not a major factor in regulating HIV-1 proviral activity in PBMC's. Unmethylated CpG's may play a role in HIV-1 immunopathogenesis. © 2013 Elsevier Inc. All rights reserved.

  18. HIV-1 RNAs are Not Part of the Argonaute 2 Associated RNA Interference Pathway in Macrophages.

    Directory of Open Access Journals (Sweden)

    Valentina Vongrad

    Full Text Available MiRNAs and other small noncoding RNAs (sncRNAs are key players in post-transcriptional gene regulation. HIV-1 derived small noncoding RNAs (sncRNAs have been described in HIV-1 infected cells, but their biological functions still remain to be elucidated. Here, we approached the question whether viral sncRNAs may play a role in the RNA interference (RNAi pathway or whether viral mRNAs are targeted by cellular miRNAs in human monocyte derived macrophages (MDM.The incorporation of viral sncRNAs and/or their target RNAs into RNA-induced silencing complex was investigated using photoactivatable ribonucleoside-induced cross-linking and immunoprecipitation (PAR-CLIP as well as high-throughput sequencing of RNA isolated by cross-linking immunoprecipitation (HITS-CLIP, which capture Argonaute2-bound miRNAs and their target RNAs. HIV-1 infected monocyte-derived macrophages (MDM were chosen as target cells, as they have previously been shown to express HIV-1 sncRNAs. In addition, we applied small RNA deep sequencing to study differential cellular miRNA expression in HIV-1 infected versus non-infected MDMs.PAR-CLIP and HITS-CLIP data demonstrated the absence of HIV-1 RNAs in Ago2-RISC, although the presence of a multitude of HIV-1 sncRNAs in HIV-1 infected MDMs was confirmed by small RNA sequencing. Small RNA sequencing revealed that 1.4% of all sncRNAs were of HIV-1 origin. However, neither HIV-1 derived sncRNAs nor putative HIV-1 target sequences incorporated into Ago2-RISC were identified suggesting that HIV-1 sncRNAs are not involved in the canonical RNAi pathway nor is HIV-1 targeted by this pathway in HIV-1 infected macrophages.

  19. HIV-1 Modulates the tRNA Pool to Improve Translation Efficiency

    Science.gov (United States)

    van Weringh, Anna; Ragonnet-Cronin, Manon; Pranckeviciene, Erinija; Pavon-Eternod, Mariana; Kleiman, Lawrence; Xia, Xuhua

    2011-01-01

    Despite its poorly adapted codon usage, HIV-1 replicates and is expressed extremely well in human host cells. HIV-1 has recently been shown to package non-lysyl transfer RNAs (tRNAs) in addition to the tRNALys needed for priming reverse transcription and integration of the HIV-1 genome. By comparing the codon usage of HIV-1 genes with that of its human host, we found that tRNAs decoding codons that are highly used by HIV-1 but avoided by its host are overrepresented in HIV-1 virions. In particular, tRNAs decoding A-ending codons, required for the expression of HIV's A-rich genome, are highly enriched. Because the affinity of Gag-Pol for all tRNAs is nonspecific, HIV packaging is most likely passive and reflects the tRNA pool at the time of viral particle formation. Codon usage of HIV-1 early genes is similar to that of highly expressed host genes, but codon usage of HIV-1 late genes was better adapted to the selectively enriched tRNA pool, suggesting that alterations in the tRNA pool are induced late in viral infection. If HIV-1 genes are adapting to an altered tRNA pool, codon adaptation of HIV-1 may be better than previously thought. PMID:21216840

  20. HIV-1感染对NK细胞及其活化性受体CD226表达的影响%Induced abnormal activation receptor CD226 expression on the peripheral blood natural killer cells in HIV-1 infected individuals

    Institute of Scientific and Technical Information of China (English)

    叶晓卉; 尚红; 马东初; 张子宁; 贾卫; 姜拥军; 金伯泉

    2003-01-01

    目的评价HIV-1感染对NK细胞以及CD226/PTA1表达的影响. 方法采用流式细胞术分析了27例HIV-1感染者以及16例健康献血员NK细胞相关膜抗原,用HIV-1SF33株体外感染外周血单个核细胞(PBMC),进行NK细胞活化表达CD226的动态观察. 结果 27例HIV-1感染者均处于无症状感染期,CD16+CD3-、CD8+CD3-细胞亚群百分率和绝对数均低于健康对照 (P<0.05),CD16+CD3-和CD8+CD3-细胞中表达CD226的细胞比例显著高于对照 (P<0.05).HIV-1和PHA均可体外诱导CD226在CD16+NK细胞表面高水平表达. 结论 CD226分子可能参与HIV-1感染诱导的NK细胞活化机制.

  1. HIV-1CRF07B/C亚型gp41的表达、纯化和初步结构分析%Prokaryotic Expression, Purification and Crystallization of HIV-1 CRF07 B/C Subtype gp41 Helix-bundle

    Institute of Scientific and Technical Information of China (English)

    王建新; 王敏; 张同存; 刘新奇

    2011-01-01

    HIV-1 transmembrane protein gp41, which plays an important role in the fusion of viral and cellular membranes, is the ideal target for intervention of HIV-1 infection. In order to obtain gp41 crystal structure from prevalent strain in China, gp41 helix-bu%HIV-1跨膜蛋白gp41是HIV-1包膜与靶细胞膜融合过程中的关键蛋白,而且序列保守,是理想的HIV-1作用靶点。为获得HIV-1中国流行株CRF07B/Cgp41蛋白的晶体结构来指导疫苗设计及药物开发,采用CRF07B/Cgp160基因序列为模板,经PCR、酶切、连接,将gp41helix—bundle区域克隆到pET30-his表达载体中,经表达、纯化和结晶筛选,获得了gp41helix—bundle的晶体并解析了结构,为针对中国艾滋病病毒流行株疫苗的设计及药物开发提供了结构参考。

  2. Penetration enhancement in mouse skin and lipolysis in adipocytes by TAT-GKH, a new cosmetic ingredient.

    Science.gov (United States)

    Lim, Jun Man; Chang, Min Youl; Park, Sun Gyoo; Kang, Nae Gyu; Song, Young Sook; Lee, Young Hwa; Yoo, Young Chang; Cho, Wan Goo; Choi, Soo Young; Kang, She Hoon

    2003-01-01

    Since the basic domain of human immunodeficiency virus type I (HIV-1) transactivator of transcription (TAT) protein was reported to possess the ability to traverse biological membranes efficiently, various therapeutic proteins have been attached to TAT for the purpose of therapy. In this study, the tripeptide GKH (glycine-lysine-histidine) derived from parathyroid hormone (PTH), known as lipolytic peptide, was attached to 9-poly lysine (TAT) to be used as a cosmetic ingredient in slimming products. TAT-GKH at 10(-5) M induced approximately 37.6% and 41.5% maximal lipolytic effects in cultured 3T3-L1 differentiated adipocytes and in epididymal adipocytes isolated from rats, respectively, compared with basal lipolysis. The lipolytic effect of GKH was not changed by TAT-GKH fusion. In cytotoxicity tests, there was no cytotoxicity in any dose concentration of TAT-GKH. We confirmed that TAT-GKH induced lipolytic activity by GKH without cytotoxicity and with the possibility of its use as a safe cosmetic ingredient. TAT-GKH elevated penetration into excised hairless mice skin 36 times more efficiently than GKH. TAT-GKH can be used as a cosmetic ingredient in slimming products, with both penetration enhancement and lipolytic effect without cytotoxicity.

  3. HIV-1, Methamphetamine and Astrocytes at Neuroinflammatory crossroads

    Directory of Open Access Journals (Sweden)

    Kathleen eBorgmann

    2015-10-01

    Full Text Available As a popular psychostimulant, methamphetamine (METH use leads to long-lasting, strong euphoric effects. While METH abuse is common in the general population, between 10-15% 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 decreases adherence to antiretroviral drug regimens, increasing the likelihood of HIV-1 disease progression towards AIDS. METH exposure also directly affects both innate and adaptive immunity, altering lymphocyte number and activity, cytokine signaling, phagocytic function, and CNS infiltration through the blood brain barrier. Further, METH triggers the neuronal dopamine reward pathway and leads to altered neuronal activity and direct toxicity. Concurrently, METH and HIV-1 alter the neuroimmune balance and induce neuroinflammation. Neuroinflammation modulates a wide range of brain functions including neuronal signaling and activity, glial activation, viral infection, oxidative stress and excitotoxicity. Pathologically, glial activation 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 alterations in astrocyte intracellular signaling pathways, gene expression and function during METH and HIV-1 comorbidity, neuroinflammation and HAND are carefully reviewed. Interventions targeting astrocytes in HAND and METH are presented as potential novel therapeutic approaches.

  4. Cyclophilin B enhances HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    DeBoer, Jason; Madson, Christian J. [Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE (United States); Belshan, Michael, E-mail: michaelbelshan@creighton.edu [Department of Medical Microbiology and Immunology, Creighton University, Omaha, NE (United States); The Nebraska Center for Virology, University of Nebraska, Lincoln, NE (United States)

    2016-02-15

    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. - Highlights: • CypB has been identified in several proteomic studies of HIV-1 infection. • CypB expression is upregulated in activated and infected T-cells. • Over-expression of CypB enhances HIV nuclear import and infection. • The N-terminus of CypB is necessary for these effects.

  5. The use of Nanotrap particles technology in capturing HIV-1 virions and viral proteins from infected cells.

    Directory of Open Access Journals (Sweden)

    Elizabeth Jaworski

    Full Text Available HIV-1 infection results in a chronic but incurable illness since long-term HAART can keep the virus to an undetectable level. However, discontinuation of therapy rapidly increases viral burden. Moreover, patients under HAART frequently develop various metabolic disorders and HIV-associated neuronal disease. Today, the main challenge of HIV-1 research is the elimination of the residual virus in infected individuals. The current HIV-1 diagnostics are largely comprised of serological and nucleic acid based technologies. Our goal is to integrate the nanotrap technology into a standard research tool that will allow sensitive detection of HIV-1 infection. This study demonstrates that majority of HIV-1 virions in culture supernatants and Tat/Nef proteins spiked in culture medium can be captured by nanotrap particles. To determine the binding affinities of different baits, we incubated target molecules with nanotrap particles at room temperature. After short sequestration, materials were either eluted or remained attached to nanotrap particles prior to analysis. The unique affinity baits of nanotrap particles preferentially bound HIV-1 materials while excluded albumin. A high level capture of Tat or Tat peptide by NT082 and NT084 particles was measured by western blot (WB. Intracellular Nef protein was captured by NT080, while membrane-associated Nef was captured by NT086 and also detected by WB. Selective capture of HIV-1 particles by NT073 and NT086 was measured by reverse transcriptase assay, while capture of infectious HIV-1 by these nanoparticles was demonstrated by functional transactivation in TZM-bl cells. We also demonstrated specific capture of HIV-1 particles and exosomes-containing TAR-RNA in patients' serum by NT086 and NT082 particles, respectively, using specific qRT-PCR. Collectively, our data indicate that certain types of nanotrap particles selectively capture specific HIV-1 molecules, and we propose to use this technology as a

  6. The Use of Nanotrap Particles Technology in Capturing HIV-1 Virions and Viral Proteins from Infected Cells

    Science.gov (United States)

    Sampey, Gavin; Shafagati, Nazly; Van Duyne, Rachel; Iordanskiy, Sergey; Kehn-Hall, Kylene; Liotta, Lance; Petricoin, Emanuel; Young, Mary; Lepene, Benjamin; Kashanchi, Fatah

    2014-01-01

    HIV-1 infection results in a chronic but incurable illness since long-term HAART can keep the virus to an undetectable level. However, discontinuation of therapy rapidly increases viral burden. Moreover, patients under HAART frequently develop various metabolic disorders and HIV-associated neuronal disease. Today, the main challenge of HIV-1 research is the elimination of the residual virus in infected individuals. The current HIV-1 diagnostics are largely comprised of serological and nucleic acid based technologies. Our goal is to integrate the nanotrap technology into a standard research tool that will allow sensitive detection of HIV-1 infection. This study demonstrates that majority of HIV-1 virions in culture supernatants and Tat/Nef proteins spiked in culture medium can be captured by nanotrap particles. To determine the binding affinities of different baits, we incubated target molecules with nanotrap particles at room temperature. After short sequestration, materials were either eluted or remained attached to nanotrap particles prior to analysis. The unique affinity baits of nanotrap particles preferentially bound HIV-1 materials while excluded albumin. A high level capture of Tat or Tat peptide by NT082 and NT084 particles was measured by western blot (WB). Intracellular Nef protein was captured by NT080, while membrane-associated Nef was captured by NT086 and also detected by WB. Selective capture of HIV-1 particles by NT073 and NT086 was measured by reverse transcriptase assay, while capture of infectious HIV-1 by these nanoparticles was demonstrated by functional transactivation in TZM-bl cells. We also demonstrated specific capture of HIV-1 particles and exosomes-containing TAR-RNA in patients' serum by NT086 and NT082 particles, respectively, using specific qRT-PCR. Collectively, our data indicate that certain types of nanotrap particles selectively capture specific HIV-1 molecules, and we propose to use this technology as a platform to enhance HIV-1

  7. 中国HIV-1 CRF01_AE流行株结构基因和调节/辅助基因DNA疫苗的构建和免疫原性研究%Immunogenicity of DNA vaccines encoding structural proteins and regulatory/accessory proteins derived from an HIV-1 CRF01_AE isolate circulating in China

    Institute of Scientific and Technical Information of China (English)

    袁松华; 徐建青; 万延民; 仇超; 张聪优; 黄杨; 乔勇; 叶芮琪; 邱趁丽; 张晓燕

    2010-01-01

    目的 构建表达gag-env融合基因和tat-rev-integrase(c-holf)-vif-nef融合基因的DNA疫苗,并评价其免疫原性.方法 按人源密码子使用频率对AE2f株的gag、env、tat、rev、integrase、vif和nef基因序列进行优化,构建真核表达质粒.用Western blot法验证体外表达情况;用ELISPOT法检测小鼠的细胞免疫反应.结果 限制性酶切及DNA测序结果表明两个融合基因质粒构建正确,可以表达相应的融合蛋白.ELISPOT结果显示,Gag-Env特异性的T细胞反应强度为(3010±566)SFC/10~6脾细胞;Tat-Rev-Integrase(C-half)-Vif-Nef融合蛋白特异性的T细胞反应为(948±737)SFC/10~6脾细胞,均显著高于空载体组.结论 构建的表达HIV-1 CRF01_AE流行株gag-env融合基因和tat-rev-integrase(c-half)-vif-nef融合基因的DNA疫苗可以正确表达所编码的融合蛋白并有效地激活机体的T细胞免疫反应.%Objective To construct two DNA vaccines encoding Gag-Env fusion protein and Tat-Rev-Integrase(C-half)-Vif-Nef fusion protein derived from the first HIV-1 CRF01_AE isolate(AE2f) in Chi-na and to evaluate the immunogenicity in mice. Methods Two DNA vaccines were constructed by inserting the codon optimized and synthesized gag-env fusion gene and tat-rev-integrase(c-half)-vif-nef fusion gene de-rived from AE2f into mammalian expression vector pDRVISV1. 0, the generated DNA vaccines were desig-nated as pSVAE/GE and pSVAE/TRIVN, respectively, and their in vitro expression were determined by Western blot with transfected 293T cells. Mice were i. m. immunized with either pDRVI1.0 as mock control, pSVAE/GE or pSYAE/TRIVN for 4 times at two-week interval. Two weeks following the final im-munization, cellular responses to pool of HIV-1 Env, Gag, Tat, Rev, Intergrase, Vif and Nef peptides were evaluated by ELISPOT assay. Results The construction of DNA vaccine pSVAE/GE and pSVAE/TRIVN was validated by restriction enzyme digestion and bidirectional sequencing. Western blot showed a

  8. A Case of Seronegative HIV-1 Infection

    OpenAIRE

    Spivak, Adam M; Brennan, Tim; O'Connell, Karen; Sydnor, Emily; Thomas M Williams; Robert F. Siliciano; Gallant, Joel E.; Blankson, Joel N.

    2010-01-01

    Patients infected with HIV-1 typically seroconvert within weeks of primary infection. In rare cases, patients do not develop antibodies against HIV-1 despite demonstrable infection. We describe an HLA-B*5802 positive individual who presented with AIDS despite repeatedly negative HIV-1 antibody screening tests. Phylogenetic analysis of env clones revealed little sequence diversity, and weak HIV-1 specific CD8+ T cell responses were present to Gag epitopes. The patient seroconverted after immun...

  9. Antigen-driven C–C Chemokine-mediated HIV-1 Suppression by CD4+ T Cells from Exposed Uninfected Individuals Expressing the Wild-type CCR-5 Allele

    OpenAIRE

    1997-01-01

    Despite repeated exposure to HIV-1, certain individuals remain persistently uninfected. Such exposed uninfected (EU) people show evidence of HIV-1–specific T cell immunity and, in rare cases, selective resistance to infection by macrophage-tropic strains of HIV-1. The latter has been associated with a 32–base pair deletion in the C–C chemokine receptor gene CCR-5, the major coreceptor of macrophage-tropic strains of HIV-1. We have undertaken an analysis of the HIV-specific T cell responses in...

  10. Diagnostik af HIV-1 infektionen

    DEFF Research Database (Denmark)

    Christiansen, C B; Dickmeiss, E; Bygbjerg, Ib Christian

    1991-01-01

    Different methods have been developed for the diagnosis of HIV infection, i.e. detection of antibodies, antigen and proviral DNA. ELISA methods for detecting HIV-1 antibodies are widely used as screening assays. A sample which is repeatedly positive with ELISA is re-tested with a confirmatory test....... For research purposes, detection of small amounts of proviral DNA can be made with polymerase chain reaction (PCR). The method is not yet applicable in routine diagnosis of HIV infection......., e.g. western blot. Antibodies to HIV-1 are not detectable until 2-3 months after infection, but antigens may be detectable during the last weeks of this initial period, though they disappear with the appearance of the antibodies. In the later stages of HIV infection, HIV antigen is again detectable...

  11. Curcumin derivatives as HIV-1 protease inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Sui, Z.; Li, J.; Craik, C.S.; Ortiz de Montellano, P.R. [Univ. of California, San Francisco, CA (United States)

    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.

  12. TAT-mediated transduction of MafA protein in utero results in enhanced pancreatic insulin expression and changes in islet morphology.

    Directory of Open Access Journals (Sweden)

    Nancy Vargas

    Full Text Available Alongside Pdx1 and Beta2/NeuroD, the transcription factor MafA has been shown to be instrumental in the maintenance of the beta cell phenotype. Indeed, a combination of MafA, Pdx1 and Ngn3 (an upstream regulator of Beta2/NeuroD was recently reported to lead to the effective reprogramming of acinar cells into insulin-producing beta cells. These experiments set the stage for the development of new strategies to address the impairment of glycemic control in diabetic patients. However, the clinical applicability of reprogramming in this context is deemed to be poor due to the need to use viral vehicles for the delivery of the above factors. Here we describe a recombinant transducible version of the MafA protein (TAT-MafA that penetrates across cell membranes with an efficiency of 100% and binds to the insulin promoter in vitro. When injected in utero into living mouse embryos, TAT-MafA significantly up-regulates target genes and induces enhanced insulin production as well as cytoarchitectural changes consistent with faster islet maturation. As the latest addition to our armamentarium of transducible proteins (which already includes Pdx1 and Ngn3, the purification and characterization of a functional TAT-MafA protein opens the door to prospective therapeutic uses that circumvent the use of viral delivery. To our knowledge, this is also the first report on the use of protein transduction in utero.

  13. Adenosine deaminase acting on RNA-1 (ADAR1 inhibits HIV-1 replication in human alveolar macrophages.

    Directory of Open Access Journals (Sweden)

    Michael D Weiden

    Full Text Available While exploring the effects of aerosol IFN-γ treatment in HIV-1/tuberculosis co-infected patients, we observed A to G mutations in HIV-1 envelope sequences derived from bronchoalveolar lavage (BAL of aerosol IFN-γ-treated patients and induction of adenosine deaminase acting on RNA 1 (ADAR1 in the BAL cells. IFN-γ induced ADAR1 expression in monocyte-derived macrophages (MDM but not T cells. ADAR1 siRNA knockdown induced HIV-1 expression in BAL cells of four HIV-1 infected patients on antiretroviral therapy. Similar results were obtained in MDM that were HIV-1 infected in vitro. Over-expression of ADAR1 in transformed macrophages inhibited HIV-1 viral replication but not viral transcription measured by nuclear run-on, suggesting that ADAR1 acts post-transcriptionally. The A to G hyper-mutation pattern observed in ADAR1 over-expressing cells in vitro was similar to that found in the lungs of HIV-1 infected patients treated with aerosol IFN-γ suggesting the model accurately represented alveolar macrophages. Together, these results indicate that ADAR1 restricts HIV-1 replication post-transcriptionally in macrophages harboring HIV-1 provirus. ADAR1 may therefore contribute to viral latency in macrophages.

  14. Anatomic dissociation between HIV-1 and its endogenous inhibitor in mucosal tissues.

    Science.gov (United States)

    Wahl, S. M.; Worley, P.; Jin, W.; McNeely, T. B.; Eisenberg, S.; Fasching, C.; Orenstein, J. M.; Janoff, E. N.

    1997-01-01

    The rarity of oral transmission of human immunodeficiency virus (HIV)-1 by saliva suggests the absence of HIV-1 in the oral cavity and/or the presence of viral inhibitory molecules. We analyzed salivary gland tissues from 55 individuals with acquired immune deficiency syndrome (AIDS) for the presence of HIV-1 by in situ hybridization and detected the virus in more than 30% of these salivary glands. These data, together with previous demonstrations of HIV-1 in oral secretions, implicate a key role for an anti-viral molecule(s) in suppressing transmission. Thus, we focused on the characterization and localization of the endogenous antiviral molecule secretory leukocyte protease inhibitor (SLPI), which inhibits HIV-1 infection in vitro. Expression of SLPI transcripts was evident in submandibular, parotid, and minor salivary glands from both HIV-1-infected and seronegative subjects. Gene expression was reflected by similar levels of SLPI protein by immunohistochemical analysis in the tissues and by enzyme-linked immunosorbent assay in the saliva. However, although SLPI accumulated in acinar cells or ductal epithelium, HIV-1 transcripts did not, and these viral transcripts were identified only in mononuclear cells within the salivary gland stroma. By in situ hybridization, we found no evidence of productive HIV-1 infection of salivary gland epithelium. Thus, HIV-1 was frequently identified in salivary gland tissue, but the virus was found in interstitial mononuclear cells only and did not co-localize with SLPI. Once within the oral cavity, HIV-1 exposure to antiviral levels of SLPI may impede infection of additional target cells, contributing to the virtual absence of oral transmission of HIV-1 by saliva. These studies emphasize the importance of innate, endogenous inhibitors of HIV-1, particularly SLPI, as effective inhibitors of HIV-1 transmission. Images Figure 1 Figure 3 Figure 4 Figure 5 PMID:9094984

  15. Multi-Faceted Post-Transcriptional Functions of HIV-1 Rev

    Directory of Open Access Journals (Sweden)

    Kuan-Teh Jeang

    2012-07-01

    Full Text Available Post-transcriptional regulation of HIV-1 gene expression is largely governed by the activities of the viral Rev protein. In this minireview, the multiple post-transcriptional activities of Rev in the export of partially spliced and unspliced HIV-1 RNAs from the nucleus to the cytoplasm, in the translation of HIV-1 transcripts, and in the packaging of viral genomic RNAs are reviewed in brief.

  16. Clinical significance of HIV-1 coreceptor usage

    Directory of Open Access Journals (Sweden)

    Lusso Paolo

    2010-01-01

    Full Text Available Abstract The identification of phenotypically distinct HIV-1 variants with different prevalence during the progression of the disease has been one of the earliest discoveries in HIV-1 biology, but its relevance to AIDS pathogenesis remains only partially understood. The physiological basis for the phenotypic variability of HIV-1 was elucidated with the discovery of distinct coreceptors employed by the virus to infect susceptible cells. The role of the viral phenotype in the variable clinical course and treatment outcome of HIV-1 infection has been extensively investigated over the past two decades. In this review, we summarize the major findings on the clinical significance of the HIV-1 coreceptor usage.

  17. Regional differences in prevalence of HIV-1 discordance in Africa and enrollment of HIV-1 discordant couples into an HIV-1 prevention trial.

    Directory of Open Access Journals (Sweden)

    Jairam R Lingappa

    Full Text Available 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.

  18. Estimating the impact of plasma HIV-1 RNA reductions on heterosexual HIV-1 transmission risk.

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    Jairam R Lingappa

    Full Text Available BACKGROUND: The risk of sexual transmission of HIV-1 is strongly associated with the level of HIV-1 RNA in plasma making reduction in HIV-1 plasma levels an important target for HIV-1 prevention interventions. A quantitative understanding of the relationship of plasma HIV-1 RNA and HIV-1 transmission risk could help predict the impact of candidate HIV-1 prevention interventions that operate by reducing plasma HIV-1 levels, such as antiretroviral therapy (ART, therapeutic vaccines, and other non-ART interventions. METHODOLOGY/PRINCIPAL FINDINGS: We use prospective data collected from 2004 to 2008 in East and Southern African HIV-1 serodiscordant couples to model the relationship of plasma HIV-1 RNA levels and heterosexual transmission risk with confirmation of HIV-1 transmission events by HIV-1 sequencing. The model is based on follow-up of 3381 HIV-1 serodiscordant couples over 5017 person-years encompassing 108 genetically-linked HIV-1 transmission events. HIV-1 transmission risk was 2.27 per 100 person-years with a log-linear relationship to log(10 plasma HIV-1 RNA. The model predicts that a decrease in average plasma HIV-1 RNA of 0.74 log(10 copies/mL (95% CI 0.60 to 0.97 reduces heterosexual transmission risk by 50%, regardless of the average starting plasma HIV-1 level in the population and independent of other HIV-1-related population characteristics. In a simulated population with a similar plasma HIV-1 RNA distribution the model estimates that 90% of overall HIV-1 infections averted by a 0.74 copies/mL reduction in plasma HIV-1 RNA could be achieved by targeting this reduction to the 58% of the cohort with plasma HIV-1 levels ≥4 log(10 copies/mL. CONCLUSIONS/SIGNIFICANCE: This log-linear model of plasma HIV-1 levels and risk of sexual HIV-1 transmission may help estimate the impact on HIV-1 transmission and infections averted from candidate interventions that reduce plasma HIV-1 RNA levels.

  19. Inhibition of replication of HIV-1 at both early and late stages of the viral life cycle by single-chain antibody against viral integrase.

    Science.gov (United States)

    Kitamura, Y; Ishikawa, T; Okui, N; Kobayashi, N; Kanda, T; Shimada, T; Miyake, K; Yoshiike, K

    1999-02-01

    Retroviruses including HIV-1 integrates a DNA copy of their RNA genome into cellular DNA of the infected cell. This reaction, essential and unique to replication of retroviruses, is mediated by the viral enzyme, integrase (IN). We constructed a recombinant gene encoding a single-chain, antigen-binding peptide (scAb2-19), which interacted with a carboxyl terminal part of HIV-1 IN. HeLa CD4 cells expressing scAb2-19 localized in either cytoplasmic or nuclear compartment were resistant to HIV-1 infection at an multiplicity of infection (MOI) of 0.25 or 0.063, but the resistance was overcome when MOI was increased to 1. To determine whether this resistance was due to inhibition of the early events, transduction experiments were performed with a replication-incompetent HIV-1 vector carrying bacterial lacZ driven by an internal Tat-independent cytomegalovirus immediate early promoter. Both cytoplasmic and nuclear expressions of scAb2-19 resulted in decrease in the transduction efficiency on HeLa CD4 cells. This implies that an early step of replication--before or during integration--was affected by the scAb2-19. Furthermore, cytoplasmic expression of scAb2-19 did not affect the viral amount released from the cells transfected with HIV-1 infectious clone DNA (pLAI). However, infectivity relative to reverse transcriptase activity was lower for virions released from the 293T cells cotransfected with pLAI and the cytoplasmic scAb2-19 expression plasmid than for those released from the 293T cells transfected with pLAI alone. This implies that scAb2-19 reduced infectivity of released virions by interfering a late step of the viral replication. The single-chain, antigen-binding peptide molecule may prove useful not only for studies of the functions of IN and its role in the viral life cycle but also for developing a gene therapy strategy against AIDS.

  20. Altered fat differentiation and adipocytokine expression are inter-related and linked to morphological changes and insulin resistance in HIV-1-infected lipodystrophic patients

    National Research Council Canada - National Science Library

    Jan, Véronique; Cervera, Pascale; Maachi, Mustapha; Baudrimont, Marielle; Kim, Minji; Vidal, Hubert; Girard, Pierre-Marie; Levan, Philippe; Rozenbaum, Willy; Lombès, Anne; Capeau, Jacqueline; Bastard, Jean-Philippe

    2004-01-01

    ... together with fat morphology and we studied the relationship between changes in fat morphology, adipocytokine expression, markers of adipose tissue differentiation and whole body insulin sensitivity...

  1. HIV-1 evades innate immune recognition through specific cofactor recruitment

    Science.gov (United States)

    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.

  2. HIV-1 and GBV-C co-infection in Venezuela.

    Science.gov (United States)

    Rodríguez, Anny Karely; Garzaro, Domingo José; Loureiro, Carmen Luisa; Gutiérrez, Cristina R; Ameli, Gladys; Jaspe, Rossana Celeste; Porto, Leticia; Monsalve, Francisca; Pozada, Ángela; Vázquez, Luzmary; Quiñones-Mateu, Miguel E; Pujol, Flor Helene; Rangel, Héctor Rafael

    2014-07-14

    Co-infection with GB virus C (GBV-C) in patients infected with human immunodeficiency virus 1 (HIV-1) has been associated with prolonged survival. The aim of this study was to evaluate the prevalence of GBV-C infection among HIV-1-infected patients in Venezuela, and to determine the effects of the co-infection on the levels of relevant cytokines. Plasma samples were collected from 270 HIV-1-seronegative and 255 HIV-1-seropositive individuals. GBV-C infection was determined by RT-PCR of the NS5 region and genotyped by sequence analysis of the 5´UTR region. HIV-1 strains were characterized by sequence analysis of pol, vif, env, and nef genes. Selected cytokines were evaluated by ELISA. Ninety-seven of 525 (18.5%) plasma samples tested positive for GBV-C RNA. A significantly higher prevalence of GBV-C was found among HIV-1 patients compared to HIV-1-seronegative individuals (67/255, 26% versus 30/270, 11%; p HIV-1+GBV-C+ and HIV-1+GBV-C- (p = 0.014), although no differences in CD4+ cell counts were found between both groups. TNFα concentration was higher in HIV-1+GBV-C- than in HIV-1+GBV-C+ patients (25.9 pg/mL versus 17.3 pg/mL; p = 0.02); RANTES expression levels were more variable in GBV-C co-infected patients and more frequently elevated in HIV-1 mono-infected patients compared to patients co-infected with GBV-C. The previously observed beneficial effect of co-infection with HIV-1 and GBV-C on disease progression is complex and might be due in part to a change in the cytokine environment. More studies are required to understand the interaction between both viruses.

  3. Antiretroviral treatment effect on immune activation reduces cerebrospinal fluid HIV-1 infection.

    Science.gov (United States)

    Sinclair, Elizabeth; Ronquillo, Rollie; Lollo, Nicole; Deeks, Steven G; Hunt, Peter; Yiannoutsos, Constantin T; Spudich, Serena; Price, Richard W

    2008-04-15

    To define the effect of antiretroviral therapy (ART) on activation of T cells in cerebrospinal fluid (CSF) and blood, and interactions of this activation with CSF HIV-1 RNA concentrations. Cross-sectional analysis of 14 HIV-negative subjects and 123 neuroasymptomatic HIV-1-infected subjects divided into 3 groups: not on ART (termed "offs"), on ART with plasma HIV-1 RNA >500 copies/mL ("failures"), and on ART with plasma HIV-1 RNA HIV-1, it maintained a coincident relation to CSF HIV-1 in both viremic groups. In addition to correlation with CSF HIV-1 concentrations, CD8 activation in blood and CSF correlated with CSF WBCs and CSF neopterin. Multivariate analysis confirmed the association of blood CD8 T-cell activation, along with plasma HIV-1 RNA and CSF neopterin, with CSF HIV-1 RNA levels. The similarity of CD8 T-cell activation in blood and CSF suggests these cells move from blood to CSF with only minor changes in CD38/HLA-DR expression. Differences in the relation of CD8 activation to HIV-1 concentrations in the blood and CSF in the 2 viremic groups suggest that changes in immune activation not only modulate CSF HIV-1 replication but also contribute to CSF treatment effects. The magnitude of systemic HIV-1 infection and intrathecal macrophage activation are also important determinants of CSF HIV-1 RNA levels.

  4. Expression levels of the innate response gene RIG-I and its regulators RNF125 and TRIM25 in HIV-1-infected adult and pediatric individuals.

    Science.gov (United States)

    Britto, Alan M A; Amoedo, Nívea D; Pezzuto, Paula; Afonso, Adriana O; Martínez, Ana M B; Silveira, Jussara; Sion, Fernando S; Machado, Elizabeth S; Soares, Marcelo A; Giannini, Ana L M

    2013-07-31

    TLRs (Toll-like receptors) and RLRs (RIG-I-like receptors) mediate innate immune responses by detecting microorganism invasion. RIG-I activation results in the production of interferon (IFN) type 1 and IFN responsive genes (ISGs). As the ubiquitin ligases RNF125 and TRIM25 are involved in regulating RIG-I function, our aim was to assess whether the levels of these three genes vary between healthy and HIV-infected individuals and whether these levels are related to disease progression. Gene expression analyses for RIG-I, RNF125, and TRIM25 were performed for HIV-infected adults and the children's peripheral blood mononuclear cells (PBMCs). Reverse transcription-quantitative PCRs (RT-qPCRs) were performed in order to quantify the expression levels of RIG-I, RNF125 and TRIM25 from PBMCs purified from control or HIV-infected individuals. Controls express higher levels of the three genes when compared to HIV-infected patients. These expressions are clearly distinct between healthy and progressors, and are reproduced in adults and children. In controls, RNF125 is the highest expressed gene, whereas in progressors, RIG-I is either the highest expressed gene or is expressed similarly to RNF125 and TRIM25. A pattern of expression of RIG-I, RNF125, and TRIM25 genes in HIV patients is evident. The high expression of RNF125 in healthy individuals reflects the importance of keeping RIG-I function off, inhibiting unnecessary IFN production. Consistent with this assumption, RNF125 levels are lower in HIV patients and importantly, the RNF125/RIG-I ratio is lower in patients who progress to AIDS. Our results might help to predict disease progression and unveil the role of poorly characterized host genes during HIV infection.

  5. Monoclonal Antibodies Recognizing HIV-1 gp41 Could Inhibit Env-Mediated Syncytium Formation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Geng; CHEN Yinghua

    2005-01-01

    Some monoclonal antibodies (mAbs) could inhibit infection by HIV-1. In this study, four mAbs against HIV-1 gp41 were prepared in mice. All four mAbs could bind to the recombinant soluble gp41 and recognize the native envelope glycoprotein gp160 expressed on the HIV-Env+ CHO-WT cell in flow cytometry analysis. Interestingly, the results show that all four mAbs purified by affinity chromatography could inhibit HIV-1 Env-mediated membrane fusion (syncytium formation) by 40%-60% at 10 μg/mL, which implies potential inhibitory activities against HIV-1.

  6. Construction of doxycyline-dependent mini-HIV-1 variants for the development of a virotherapy against leukemias

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2006-09-01

    Full Text Available Abstract T-cell acute lymphoblastic leukemia (T-ALL is a high-risk type of blood-cell cancer. We describe the improvement of a candidate therapeutic virus for virotherapy of leukemic cells. Virotherapy is based on the exclusive replication of a virus in leukemic cells, leading to the selective removal of these malignant cells. To improve the safety of such a virus, we constructed an HIV-1 variant that replicates exclusively in the presence of the nontoxic effector doxycycline (dox. This was achieved by replacement of the viral TAR-Tat system for transcriptional activation by the Escherichia coli-derived Tet system for inducible gene expression. This HIV-rtTA virus replicates in a strictly dox-dependent manner. In this virus, additional deletions and/or inactivating mutations were introduced in the genes for accessory proteins. These proteins are essential for virus replication in untransformed cells, but dispensable in leukemic T cells. These minimized HIV-rtTA variants contain up to 7 deletions/inactivating mutations (TAR, Tat, vif, vpR, vpU, nef and U3 and replicate efficiently in the leukemic SupT1 T cell line, but do not replicate in normal peripheral blood mononuclear cells. These virus variants are also able to efficiently remove leukemic cells from a mixed culture with untransformed cells. The therapeutic viruses use CD4 and CXCR4 for cell entry and could potentially be used against CXCR4 expressing malignancies such as T-lymphoblastic leukemia/lymphoma, NK leukemia and some myeloid leukemias.

  7. Down-regulation of cell surface CXCR4 by HIV-1

    Directory of Open Access Journals (Sweden)

    Vigh Sandor

    2008-01-01

    Full Text Available Abstract Background CXC chemokine receptor 4 (CXCR4, a member of the G-protein-coupled chemokine receptor family, can serve as a co-receptor along with CD4 for entry into the cell of T-cell tropic X4 human immunodeficiency virus type 1 (HIV-1 strains. Productive infection of T-lymphoblastoid cells by X4 HIV-1 markedly reduces cell-surface expression of CD4, but whether or not the co-receptor CXCR4 is down-regulated has not been conclusively determined. Results Infection of human T-lymphoblastoid cell line RH9 with HIV-1 resulted in down-regulation of cell surface CXCR4 expression. Down-regulation of surface CXCR4 correlated temporally with the increase in HIV-1 protein expression. CXCR4 was concentrated in intracellular compartments in H9 cells after HIV-1 infection. Immunofluorescence microscopy studies showed that CXCR4 and HIV-1 glycoproteins were co-localized in HIV infected cells. Inducible expression of HIV-1 envelope glycoproteins also resulted in down-regulation of CXCR4 from the cell surface. Conclusion These results indicated that cell surface CXCR4 was reduced in HIV-1 infected cells, whereas expression of another membrane antigen, CD3, was unaffected. CXCR4 down-regulation may be due to intracellular sequestering of HIV glycoprotein/CXCR4 complexes.

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

    Science.gov (United States)

    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.

  9. The macrophage in HIV-1 infection: From activation to deactivation?

    Directory of Open Access Journals (Sweden)

    Varin Audrey

    2010-04-01

    Full Text Available Abstract Macrophages play a crucial role in innate and adaptative immunity in response to microorganisms and are an important cellular target during HIV-1 infection. Recently, the heterogeneity of the macrophage population has been highlighted. Classically activated or type 1 macrophages (M1 induced in particular by IFN-γ display a pro-inflammatory profile. The alternatively activated or type 2 macrophages (M2 induced by Th-2 cytokines, such as IL-4 and IL-13 express anti-inflammatory and tissue repair properties. Finally IL-10 has been described as the prototypic cytokine involved in the deactivation of macrophages (dM. Since the capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines, this review shows how modulation of macrophage activation by cytokines impacts the capacity to support productive HIV-1 infection. Based on the activation status of macrophages we propose a model starting with M1 classically activated macrophages with accelerated formation of viral reservoirs in a context of Th1 and proinflammatory cytokines. Then IL-4/IL-13 alternatively activated M2 macrophages will enter into the game that will stop the expansion of the HIV-1 reservoir. Finally IL-10 deactivation of macrophages will lead to immune failure observed at the very late stages of the HIV-1 disease.

  10. The macrophage in HIV-1 infection: from activation to deactivation?

    Science.gov (United States)

    Herbein, Georges; Varin, Audrey

    2010-04-09

    Macrophages play a crucial role in innate and adaptative immunity in response to microorganisms and are an important cellular target during HIV-1 infection. Recently, the heterogeneity of the macrophage population has been highlighted. Classically activated or type 1 macrophages (M1) induced in particular by IFN-gamma display a pro-inflammatory profile. The alternatively activated or type 2 macrophages (M2) induced by Th-2 cytokines, such as IL-4 and IL-13 express anti-inflammatory and tissue repair properties. Finally IL-10 has been described as the prototypic cytokine involved in the deactivation of macrophages (dM). Since the capacity of macrophages to support productive HIV-1 infection is known to be modulated by cytokines, this review shows how modulation of macrophage activation by cytokines impacts the capacity to support productive HIV-1 infection. Based on the activation status of macrophages we propose a model starting with M1 classically activated macrophages with accelerated formation of viral reservoirs in a context of Th1 and proinflammatory cytokines. Then IL-4/IL-13 alternatively activated M2 macrophages will enter into the game that will stop the expansion of the HIV-1 reservoir. Finally IL-10 deactivation of macrophages will lead to immune failure observed at the very late stages of the HIV-1 disease.

  11. Expression of HIV-1 Vpu leads to loss of the viral restriction factor CD317/Tetherin from lipid rafts and its enhanced lysosomal degradation.

    Directory of Open Access Journals (Sweden)

    Ruth Rollason

    Full Text Available CD317/tetherin (aka BST2 or HM1.24 antigen is an interferon inducible membrane protein present in regions of the lipid bilayer enriched in sphingolipids and cholesterol (often termed lipid rafts. It has been implicated in an eclectic mix of cellular processes including, most notably, the retention of fully formed viral particles at the surface of cells infected with HIV and other enveloped viruses. Expression of the HIV viral accessory protein Vpu has been shown to lead to intracellular sequestration and degradation of tetherin, thereby counteracting the inhibition of viral release. There is evidence that tetherin interacts directly with Vpu, but it remains unclear where in the cell this interaction occurs or if Vpu expression affects the lipid raft localisation of tetherin. We have addressed these points using biochemical and cell imaging approaches focused on endogenous rather than ectopically over-expressed tetherin. We find i no evidence for an interaction between Vpu and endogenous tetherin at the cell surface, ii the vast majority of endogenous tetherin that is at the cell surface in control cells is in lipid rafts, iii internalised tetherin is present in non-raft fractions, iv expression of Vpu in cells expressing endogenous tetherin leads to the loss of tetherin from lipid rafts, v internalised tetherin enters early endosomes, and late endosomes, in both control cells and cells expressing Vpu, but the proportion of tetherin molecules destined for degradation rather than recycling is increased in cells expressing Vpu vi lysosomes are the primary site for degradation of endogenous tetherin in cells expressing Vpu. Our studies underlie the importance of studying endogenous tetherin and let us propose a model in which Vpu intercepts newly internalised tetherin and diverts it for lysosomal destruction rather than recycling to the cell surface.

  12. Development of dengue virus replicons expressing HIV-1 gp120 and other heterologous genes: a potential future tool for dual vaccination against dengue virus and HIV

    Directory of Open Access Journals (Sweden)

    Dayton Andrew I

    2001-11-01

    Full Text Available Abstract Background Toward the goals of providing an additional vector to add to the armamentarium available to HIV vaccinologists and of creating a bivalent vaccine effective against dengue virus and HIV, we have attempted to create vectors which express dengue virus non-structural proteins and HIV immunogens. Previously we reported the successful construction of dengue virus replicons which lack structural genes necessary for virion release and spreading infection in culture but which can replicate intracellularly and abundantly produce dengue non-structural proteins. Here we attempted to express heterologous genetic material from these replicons. Results We cloned into a Δpre-M/E dengue virus replicon genes for either green fluorescent protein (GFP, HIV gp160 or HIV gp120 and tested the ability of these constructs to express dengue virus proteins as well as the heterologous proteins in tissue culture after transfection of replicon RNA. Conclusions Heterologous proteins were readily expressed from these constructs. GFP and gp120 demonstrated minimal or no toxicity. Gp160 expressing replicons were found to express proteins abundantly at 36 hours post transfection, but after 50 hrs of transfection, few replicon positive cells could be found despite the presence of cellular debris positive for replicon proteins. This suggested that gp160 expressed from dengue virus replicons is considerably more toxic than either GFP or gp120. The successful expression of heterologous proteins, including HIV gp120 for long periods in culture suggests this vector system may be useful as a vaccine vector, given appropriate delivery methods.

  13. HIV-1 Vpr induces interferon-stimulated genes in human monocyte-derived macrophages.

    Directory of Open Access Journals (Sweden)

    Muhammad Atif Zahoor

    Full Text Available Macrophages act as reservoirs of human immunodeficiency virus type 1 (HIV-1 and play an important role in its transmission to other cells. HIV-1 Vpr is a multi-functional protein involved in HIV-1 replication and pathogenesis; however, its exact role in HIV-1-infected human macrophages remains poorly understood. In this study, we used a microarray approach to explore the effects of HIV-1 Vpr on the transcriptional profile of human monocyte-derived macrophages (MDMs. More than 500 genes, mainly those involved in the innate immune response, the type I interferon pathway, cytokine production, and signal transduction, were differentially regulated (fold change >2.0 after infection with a recombinant adenovirus expressing HIV-1 Vpr protein. The differential expression profiles of select interferon-stimulated genes (ISGs and genes involved in the innate immune response, including STAT1, IRF7, MX1, MX2, ISG15, ISG20, IFIT1, IFIT2, IFIT3, IFI27, IFI44L, APOBEC3A, DDX58 (RIG-I, TNFSF10 (TRAIL, and RSAD2 (viperin were confirmed by real-time quantitative PCR and were consistent with the microarray data. In addition, at the post-translational level, HIV-1 Vpr induced the phosphorylation of STAT1 at tyrosine 701 in human MDMs. These results demonstrate that HIV-1 Vpr leads to the induction of ISGs and expand the current understanding of the function of Vpr and its role in HIV-1 immune pathogenesis.

  14. Additive activity between the trans-activation response RNA-binding protein, TRBP2, and cyclin T1 on HIV type 1 expression and viral production in murine cells.

    Science.gov (United States)

    Battisti, Pier-Luigi; Daher, Aïcha; Bannwarth, Sylvie; Voortman, Johannes; Peden, Keith W C; Hiscott, John; Mouland, Andrew J; Benarous, Richard; Gatignol, Anne

    2003-09-01

    Tat-mediated trans-activation of the HIV-1 long terminal repeat (LTR) occurs through the phosphorylation of the carboxy-terminal domain of the RNA polymerase II. The kinase complex, pTEFb, composed of cyclin T1 (CycT1) and CDK9, mediates this process. The trans-activation response (TAR) RNA-binding protein 2 (TRBP2) increases HIV-1 LTR expression through TAR and protein kinase R (PKR) binding, but not through interactions with the Tat-CycT1-CDK9 complex. TRBP2 and the Tat-CycT1-CDK9 complex have overlapping binding sites on TAR RNA. TRBP2 and CycT1 increased Tat trans-activation in NIH 3T3 cells with additive effects. Upon transfection of HIV-1 pLAI, pNL4-3, pMAL, and pAD molecular clones, reverse transcriptase (RT) activity and p24 concentration were decreased 200- to 900-fold in NIH 3T3 cells compared with HeLa cells in both cells and supernatants. In murine cells, cotransfection of the HIV clones with CycT1 or TRBP2 increased modestly the expression of RT activity in cell extracts. The analysis of Gag expression in murine cells transfected with CycT1 compared with human cells showed a 20-fold decrease in expression and a strong processing defect. The expression of both CycT1 and TRBP2 had a more than additive activity on RT function in cell extracts and on viral particle production in supernatant of murine cells. These results suggest an activity of CycT1 and TRBP2 at different steps in HIV-1 expression and indicate the requirement for another posttranscriptional factor in murine cells for full HIV replication.

  15. HIV-1 CRF07_BC gp41重组抗原在不同体系表达效率的比较%Comparison of expression efficiency of HIV-1 CRF07_BC gp41 recombinant antigen in different expression system

    Institute of Scientific and Technical Information of China (English)

    王妮丹; 罗振武; 郝彦玲; 孙红岩; 何彦平; 邵一鸣

    2014-01-01

    目的 获得HIV-1 CRF07_BC株gp41重组抗原表达效率最佳的体系.方法 采用基因工程技术将gp41重组蛋白基因分别构建到pThioHisA,pThioHis A-1(不含标签),PBV220,PGEX-6p-1原核表达载体.转化大肠杆菌BL21和Rosetta两种宿主菌,通过IPTG诱导表达并经WB鉴定.结果 4种原核表达质粒构建完成,蛋白成功表达.PGEX-6p-1表达量明显高于pThioHis A载体;而无标签载体组中,PBV220表达量优于pThioHis A-1.BL21和Rosetta宿主菌对表达体系无影响.结论 HIV-1 CRF07_BC株gp41重组抗原在大肠杆菌中以包涵体形式存在,构建在PGEX-6p-1和PBV220载体上gp41重组蛋白表达效率较高,为gp41疫苗的研究和血清学检测提供充足的抗原.

  16. Attenuation of HIV-1 replication in macrophages by cannabinoid receptor 2 agonists.

    Science.gov (United States)

    Ramirez, Servio H; Reichenbach, Nancy L; Fan, Shongshan; Rom, Slava; Merkel, Steven F; Wang, Xu; Ho, Wen-Zhe; Persidsky, Yuri

    2013-05-01

    Infiltrating monocytes and macrophages play a crucial role in the progression of HIV-1 infection in the CNS. Previous studies showed that activation of the CB₂ can attenuate inflammatory responses and affect HIV-1 infectivity in T cells and microglia. Here, we report that CB₂ agonists can also act as immunomodulators on HIV-1-infected macrophages. First, our findings indicated the presence of elevated levels of CB₂ expression on monocytes/macrophages in perivascular cuffs of postmortem HIV-1 encephalitic cases. In vitro analysis by FACS of primary human monocytes revealed a step-wise increase in CB₂ surface expression in monocytes, MDMs, and HIV-1-infected MDMs. We next tested the notion that up-regulation of CB₂ may allow for the use of synthetic CB₂ agonist to limit HIV-1 infection. Two commercially available CB₂ agonists, JWH133 and GP1a, and a resorcinol-based CB₂ agonist, O-1966, were evaluated. Results from measurements of HIV-1 RT activity in the culture media of 7 day-infected cells showed a significant decrease in RT activity when the CB₂ agonist was present. Furthermore, CB₂ activation also partially inhibited the expression of HIV-1 pol. CB₂ agonists did not modulate surface expression of CXCR4 or CCR5 detected by FACS. We speculate that these findings indicate that prevention of viral entry is not a central mechanism for CB₂-mediated suppression in viral replication. However, CB₂ may affect the HIV-1 replication machinery. Results from a single-round infection with the pseudotyped virus revealed a marked decrease in HIV-1 LTR activation by the CB₂ ligands. Together, these results indicate that CB₂ may offer a means to limit HIV-1 infection in macrophages.

  17. Human HERC5 restricts an early stage of HIV-1 assembly by a mechanism correlating with the ISGylation of Gag

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    Woods Matthew W

    2011-11-01

    Full Text Available Abstract Background The identification and characterization of several interferon (IFN-induced cellular HIV-1 restriction factors, defined as host cellular proteins or factors that restrict or inhibit the HIV-1 life cycle, have provided insight into the IFN response towards HIV-1 infection and identified new therapeutic targets for HIV-1 infection. To further characterize the mechanism underlying restriction of the late stages of HIV-1 replication, we assessed the ability of IFNbeta-induced genes to restrict HIV-1 Gag particle production and have identified a potentially novel host factor called HECT domain and RCC1-like domain-containing protein 5 (HERC5 that blocks a unique late stage of the HIV-1 life cycle. Results HERC5 inhibited the replication of HIV-1 over multiple rounds of infection and was found to target a late stage of HIV-1 particle production. The E3 ligase activity of HERC5 was required for blocking HIV-1 Gag particle production and correlated with the post-translational modification of Gag with ISG15. HERC5 interacted with HIV-1 Gag and did not alter trafficking of HIV-1 Gag to the plasma membrane. Electron microscopy revealed that the assembly of HIV-1 Gag particles was arrested at the plasma membrane, at an early stage of assembly. The mechanism of HERC5-induced restriction of HIV-1 particle production is distinct from the mechanism underlying HIV-1 restriction by the expression of ISG15 alone, which acts at a later step in particle release. Moreover, HERC5 restricted murine leukemia virus (MLV Gag particle production, showing that HERC5 is effective in restricting Gag particle production of an evolutionarily divergent retrovirus. Conclusions HERC5 represents a potential new host factor that blocks an early stage of retroviral Gag particle assembly. With no apparent HIV-1 protein that directly counteracts it, HERC5 may represent a new candidate for HIV/AIDS therapy.

  18. Inhibition of HIV-1 replication in alveolar macrophages by adenovirus gene transfer vectors.

    Science.gov (United States)

    Rice, Joshua; Connor, Ruth; Worgall, Stefan; Moore, John P; Leopold, Philip L; Kaner, Robert J; Crystal, Ronald G

    2002-08-01

    To assess the hypothesis that infection of alveolar macrophages (AM) with adenovirus (Ad) gene transfer vectors might prevent subsequent human immunodeficiency virus (HIV)-1 replication in AM, AM isolated from normal volunteers were infected with increasing doses of first generation (E1(-)) Ad vectors, followed 72 h later by infection with HIV-1(JRFL), an R5/M-tropic strain that preferentially uses the CCR5 coreceptor. As a measure of HIV-1 replication, p24 Ag was quantified by enzyme-linked imunosorbent assay in supernatants on Days 4 to 14 after HIV-1infection. Pretreatment of the AM with an Ad vector resulted in a dose- and time-dependent suppression of subsequent HIV-1 replication. The Ad vector inhibition of HIV-1 replication was independent of the transgene in the Ad vector expression cassette and E4 genes in the Ad backbone. Moreover, it did not appear to be secondary to a soluble factor released by the AM, nor was it overridden by the concomitant transfer of the CCR5 or CXCR4 receptors to the AM before HIV-1 infection. These observations have implications regarding pulmonary host responses associated with HIV-1 infection, as well as possibly uncovering new therapeutic strategies against HIV-1 infection.

  19. Escherichia coli surface display of single-chain antibody VRC01 against HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lin-Xu [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Mellon, Michael [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States); Bowder, Dane [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Quinn, Meghan [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States); Shea, Danielle; Wood, Charles [Nebraska Center for Virology, Lincoln, NE (United States); School of Biological Sciences, University of Nebraska—Lincoln, Lincoln, NE 68583 (United States); Xiang, Shi-Hua, E-mail: sxiang2@unl.edu [Nebraska Center for Virology, Lincoln, NE (United States); School of Veterinary Medicine and Biomedical Sciences, Lincoln, NE (United States)

    2015-01-15

    Human immunodeficiency virus type 1 (HIV-1) transmission and infection occur mainly via the mucosal surfaces. The commensal bacteria residing in these surfaces can potentially be employed as a vehicle for delivering inhibitors to prevent HIV-1 infection. In this study, we have employed a bacteria-based strategy to display a broadly neutralizing antibody VRC01, which could potentially be used to prevent HIV-1 infection. The VRC01 antibody mimics CD4-binding to gp120 and has broadly neutralization activities against HIV-1. We have designed a construct that can express the fusion peptide of the scFv-VRC01 antibody together with the autotransporter β-barrel domain of IgAP gene from Neisseria gonorrhoeae, which enabled surface display of the antibody molecule. Our results indicate that the scFv-VRC01 antibody molecule was displayed on the surface of the bacteria as demonstrated by flow cytometry and immunofluorescence microscopy. The engineered bacteria can capture HIV-1 particles via surface-binding and inhibit HIV-1 infection in cell culture. - Highlights: • Designed single-chain VRC01 antibody was demonstrated to bind HIV-1 envelope gp120. • Single-chain VRC01 antibody was successfully displayed on the surface of E. coli. • Engineered bacteria can absorb HIV-1 particles and prevent HIV-1 infection in cell culture.

  20. Protective efficacy of a global HIV-1 mosaic vaccine against heterologous SHIV challenges in rhesus monkeys.

    Science.gov (United States)

    Barouch, Dan H; Stephenson, Kathryn E; Borducchi, Erica N; Smith, Kaitlin; Stanley, Kelly; McNally, Anna G; Liu, Jinyan; Abbink, Peter; Maxfield, Lori F; Seaman, Michael S; Dugast, Anne-Sophie; Alter, Galit; Ferguson, Melissa; Li, Wenjun; Earl, Patricia L; Moss, Bernard; Giorgi, Elena E; Szinger, James J; Eller, Leigh Anne; Billings, Erik A; Rao, Mangala; Tovanabutra, Sodsai; Sanders-Buell, Eric; Weijtens, Mo; Pau, Maria G; Schuitemaker, Hanneke; Robb, Merlin L; Kim, Jerome H; Korber, Bette T; Michael, Nelson L

    2013-10-24

    The global diversity of HIV-1 represents a critical challenge facing HIV-1 vaccine development. HIV-1 mosaic antigens are bioinformatically optimized immunogens designed for improved coverage of HIV-1 diversity. However, the protective efficacy of such global HIV-1 vaccine antigens has not previously been evaluated. Here, we demonstrate the capacity of bivalent HIV-1 mosaic antigens to protect rhesus monkeys against acquisition of infection following heterologous challenges with the difficult-to-neutralize simian-human immunodeficiency virus SHIV-SF162P3. Adenovirus/poxvirus and adenovirus/adenovirus vector-based vaccines expressing HIV-1 mosaic Env, Gag, and Pol afforded a significant reduction in the per-exposure acquisition risk following repetitive, intrarectal SHIV-SF162P3 challenges. Protection against acquisition of infection correlated with vaccine-elicited binding, neutralizing, and functional nonneutralizing antibodies, suggesting that the coordinated activity of multiple antibody functions may contribute to protection against difficult-to-neutralize viruses. These data demonstrate the protective efficacy of HIV-1 mosaic antigens and suggest a potential strategy for the development of a global HIV-1 vaccine. PAPERCLIP:

  1. Efficient Gene Transfer Mediated by HIV-1-based Defective Lentivector and Inhibition of HIV-1 Replication

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Lentiviral vectors have drawn considerable attention recently and show great promise to become important delivery vehicles for future gene transfer manipulation. In the present study we have optimized a protocol for preparation of human immunodeficiency virus type-1 (HIV-1)-based defective lentiviral vectors (DLV) and characterized these vectors in terms of their transduction of different cells. Transient co-transfection of 293T packaging cells with DNA plasmids encoding lentiviral vector constituents resulted in production of high-titer DLV (0.5-1.2 × 107IU/mL), which can be further concentrated over 100-fold through a single step ultracentrifugation. These vectors were capable of transducing a variety of cells from both primate and non-primate sources and high transduction efficiency was achieved using concentrated vectors. Assessment of potential generation of RCV revealed no detection of infection by infectious particles in DLV-transduced CEM, SupT-1 and MT-2 cells. Long-term culture of transduced cells showed a stable expression of transgenes without apparent alteration in cellular morphology and growth kinetics. Vector mobilization to untransduced cells mediated by wild-type HIV-1 infection was confirmed in this test. Challenge of transduced human T-lymphocytes with wild-type HIV-1 showed these cells are totally resistant to the viral infection. Considering the effective gene transfer and stable gene expression, safety and anti-HIV activity, these DLV vectors warrant further exploration for their potential use as a gene transfer vehicle in the development of gene therapy protocols.

  2. Engineering Cellular Resistance to HIV-1 Infection In Vivo Using a Dual Therapeutic Lentiviral Vector

    Directory of Open Access Journals (Sweden)

    Bryan P Burke

    2015-01-01

    Full Text Available We described earlier a dual-combination anti-HIV type 1 (HIV-1 lentiviral vector (LVsh5/C46 that downregulates CCR5 expression of transduced cells via RNAi and inhibits HIV-1 fusion via cell surface expression of cell membrane-anchored C46 antiviral peptide. This combinatorial approach has two points of inhibition for R5-tropic HIV-1 and is also active against X4-tropic HIV-1. Here, we utilize the humanized bone marrow, liver, thymus (BLT mouse model to characterize the in vivo efficacy of LVsh5/C46 (Cal-1 vector to engineer cellular resistance to HIV-1 pathogenesis. Human CD34+ hematopoietic stem/progenitor cells (HSPC either nonmodified or transduced with LVsh5/C46 vector were transplanted to generate control and treatment groups, respectively. Control and experimental groups displayed similar engraftment and multilineage hematopoietic differentiation that included robust CD4+ T-cell development. Splenocytes isolated from the treatment group were resistant to both R5- and X4-tropic HIV-1 during ex vivo challenge experiments. Treatment group animals challenged with R5-tropic HIV-1 displayed significant protection of CD4+ T-cells and reduced viral load within peripheral blood and lymphoid tissues up to 14 weeks postinfection. Gene-marking and transgene expression were confirmed stable at 26 weeks post-transplantation. These data strongly support the use of LVsh5/C46 lentiviral vector in gene and cell therapeutic applications for inhibition of HIV-1 infection.

  3. Gp120 on HIV-1 Virions Lacks O-Linked Carbohydrate.

    Directory of Open Access Journals (Sweden)

    Elizabeth Stansell

    Full Text Available As HIV-1-encoded envelope protein traverses the secretory pathway, it may be modified with N- and O-linked carbohydrate. When the gp120s of HIV-1 NL4-3, HIV-1 YU2, HIV-1 Bal, HIV-1 JRFL, and HIV-1 JRCSF were expressed as secreted proteins, the threonine at consensus position 499 was found to be O-glycosylated. For SIVmac239, the corresponding threonine was also glycosylated when gp120 was recombinantly expressed. Similarly-positioned, highly-conserved threonines in the influenza A virus H1N1 HA1 and H5N1 HA1 envelope proteins were also found to carry O-glycans when expressed as secreted proteins. In all cases, the threonines were modified predominantly with disialylated core 1 glycans, together with related core 1 and core 2 structures. Secreted HIV-1 gp140 was modified to a lesser extent with mainly monosialylated core 1 O-glycans, suggesting that the ectodomain of the gp41 transmembrane component may limit the accessibility of Thr499 to glycosyltransferases. In striking contrast to these findings, gp120 on purified virions of HIV-1 Bal and SIV CP-MAC lacked any detectable O-glycosylation of the C-terminal threonine. Our results indicate the absence of O-linked carbohydrates on Thr499 as it exists on the surface of virions and suggest caution in the interpretation of analyses of post-translational modifications that utilize recombinant forms of envelope protein.

  4. Epigenetic mechanisms, T-cell activation, and CCR5 genetics interact to regulate T-cell expression of CCR5, the major HIV-1 coreceptor.

    Science.gov (United States)

    Gornalusse, German G; Mummidi, Srinivas; Gaitan, Alvaro A; Jimenez, Fabio; Ramsuran, Veron; Picton, Anabela; Rogers, Kristen; Manoharan, Muthu Saravanan; Avadhanam, Nymisha; Murthy, Krishna K; Martinez, Hernan; Molano Murillo, Angela; Chykarenko, Zoya A; Hutt, Richard; Daskalakis, Demetre; Shostakovich-Koretskaya, Ludmila; Abdool Karim, Salim; Martin, Jeffrey N; Deeks, Steven G; Hecht, Frederick; Sinclair, Elizabeth; Clark, Robert A; Okulicz, Jason; Valentine, Fred T; Martinson, Neil; Tiemessen, Caroline Tanya; Ndung'u, Thumbi; Hunt, Peter W; He, Weijing; Ahuja, Sunil K

    2015-08-25

    T-cell expression levels of CC chemokine receptor 5 (CCR5) are a critical determinant of HIV/AIDS susceptibility, and manifest wide variations (i) between T-cell subsets and among individuals and (ii) in T-cell activation-induced increases in expression levels. We demonstrate that a unifying mechanism for this variation is differences in constitutive and T-cell activation-induced DNA methylation status of CCR5 cis-regulatory regions (cis-regions). Commencing at an evolutionarily conserved CpG (CpG -41), CCR5 cis-regions manifest lower vs. higher methylation in T cells with higher vs. lower CCR5 levels (memory vs. naïve T cells) and in memory T cells with higher vs. lower CCR5 levels. HIV-related and in vitro induced T-cell activation is associated with demethylation of these cis-regions. CCR5 haplotypes associated with increased vs. decreased gene/surface expression levels and HIV/AIDS susceptibility magnify vs. dampen T-cell activation-associated demethylation. Methylation status of CCR5 intron 2 explains a larger proportion of the variation in CCR5 levels than genotype or T-cell activation. The ancestral, protective CCR5-HHA haplotype bears a polymorphism at CpG -41 that is (i) specific to southern Africa, (ii) abrogates binding of the transcription factor CREB1 to this cis-region, and (iii) exhibits a trend for overrepresentation in persons with reduced susceptibility to HIV and disease progression. Genotypes lacking the CCR5-Δ32 mutation but with hypermethylated cis-regions have CCR5 levels similar to genotypes heterozygous for CCR5-Δ32. In HIV-infected individuals, CCR5 cis-regions remain demethylated, despite restoration of CD4+ counts (≥800 cells per mm(3)) with antiretroviral therapy. Thus, methylation content of CCR5 cis-regions is a central epigenetic determinant of T-cell CCR5 levels, and possibly HIV-related outcomes.

  5. HIV-1型gp41抗原蛋白在大肠杆菌无细胞体系中的表达和免疫反应性检测%HIV-1 Antigenic Protein Gp41: Expression in E.coil Cell-Free System and Immunoreactivity Analysis

    Institute of Scientific and Technical Information of China (English)

    来力; 杨修亮; 盛嘉元; 黄磊; 蔡谨; 徐志南

    2016-01-01

    HIV-1型gp41抗原蛋白在HIV初筛诊断中有重要应用.该研究合成了gp41全长基因序列,将其与pIVEX2.4c酶切连接构建表达载体,在大肠杆菌无细胞体系中实现了目标蛋白的全长可溶表达.考察了添加不同浓度非离子型去污剂Brij78对蛋白可溶性的影响,在0.2% Brij78条件下,可溶性gp41重组蛋白的表达水平达到650μg/mL.Ni2亲和层析纯化目标蛋白,纯度达到95.6%;超滤浓缩后,蛋白浓度为0.9 mg/mL,总回收率为70.8%.免疫反应性检测结果显示该gp41重组抗原制备的乳胶HIV抗体诊断试纸能与不同滴度的HIV-1型阳性标本反应,在检测线位置出现红色条带,而与HIV-1型阴性标本无反应.该研究制备了具有完整氨基酸序列的HIV-1型gp41重组抗原,为进一步提高HIV抗体诊断试剂的质量打下了基础.

  6. Plasmacytoid dendritic cells accumulate and secrete interferon alpha in lymph nodes of HIV-1 patients.

    Directory of Open Access Journals (Sweden)

    Clara Lehmann

    Full Text Available Circulating plasmacytoid dendritic cells (pDC decline during HIV-1 infection, but at the same time they express markedly higher levels of interferon alpha (IFNalpha, which is associated with HIV-1 disease progression. Here we show an accumulation of pDC in lymph nodes (LN of treatment-naïve HIV-1 patients. This phenomenon was associated with elevated expression of the LN homing marker, CCR7, on pDC in peripheral blood of HIV-1 patients, which conferred increased migratory capacity in response to CCR7 ligands in ex vivo functional assays. LN-homed pDC of HIV-1 patients presented higher CD40 and lower BDCA2 levels, but unchanged CD83 and CD86 expression. In addition, these cells expressed markedly higher amounts of IFNalpha compared to uninfected individuals, and were undergoing faster rates of cell death. These results demonstrate for the first time that in asymptomatic, untreated HIV-1 patients circulating pDC up-regulate CCR7 expression, accumulate in lymph nodes, and express high amounts of IFNalpha before undergoing cell death. Since IFNalpha inhibits cell proliferation and modulates immune responses, chronically high levels of this cytokine in LN of HIV-1 patients may impair differentiation and immune function of bystander CD4(+ T cells, thus playing into the mechanisms of AIDS immunopathogenesis.

  7. Breast milk transmission of HIV-1.

    Science.gov (United States)

    Nduati, R; John, G

    1995-12-01

    Breast milk provides infants and children immunologic, nutritional, and child spacing benefits. Yet it also transmits some viruses, for example, HIV-1. The World Health Organization recommends that, in conditions with poor access to breast milk substitutes, HIV-positive women should still breast feed due to the nutritional and infectious risk of artificial feeding. It appears that breast fed infants experience a slower progression of AIDS and death. Vertical transmission of HIV-1 may occur during pregnancy, at delivery, or through breast milk. The HIV-1 transmission rate via breast milk from acutely infected women is estimated to be 29-36%. A meta-analysis of case reports and small case series of women with chronic HIV-1 infection indicated a breast feeding transmission rate of 14%. Studies suggest that the likelihood of HIV-1 transmission via breast milk increases as duration of breast feeding increases. Infants with detectable HIV-1 DNA tend to have mothers whose absolute CD4 counts are less than 400 and have severe vitamin A deficiency. Breast milk has HIV-1 specific immunoglobulins (IgG, IgA, and IgM). It appears that HIV-1 elicits a local immune response. Breast milk of HIV-1 positive mothers with non-infected children tends to still have IgM and IgA until 18 months. Potential risk factors for breast milk transmission of HIV-1 include cracked nipples and mastitis in the mother; oral thrush, malnutrition, inflammation of the lips, and mucosal compromise in the infant; and vigorous suction of the neonate and use of the wrong equipment for suctioning. Inhibiting factors of HIV-1 in breast milk are bovine and human lactoferrin and a membrane associated protein that attaches to the CD4 receptor and thus prevents attachment of the HIV antigen gp120 to the CD4 receptor on T-cells.

  8. HIV-1 Gag-specific exosome-targeted T cell-based vaccine stimulates effector CTL responses leading to therapeutic and long-term immunity against Gag/HLA-A2-expressing B16 melanoma in transgenic HLA-A2 mice

    Directory of Open Access Journals (Sweden)

    Rong Wang

    2014-01-01

    Full Text Available Human immunodeficiency virus type-1 (HIV-1-specific dendritic cell (DC vaccines have been applied to clinical trials that show only induction of some degree of immune responses, warranting the search of other more efficient vaccine strategies. Since HIV-1-specific CD8+ cytotoxic T lymphocytes (CTLs have been found to recognize some HIV-1 structural protein Gag conserved and cross-strain epitopes, Gag has become one of the most attractive target candidates for HIV-1 vaccine development. In this study, we generated HIV-1 Gag-specific Gag-Texo vaccine by using ConA-stimulated polyclonal CD8+ T-cells with uptake of Gag-expressing adenoviral vector AdVGag-transfected DC (DCGag-released exosomes (EXOs, and assessed its stimulation of Gag-specific CD8+ CTL responses and antitumor immunity. We demonstrate that Gag-Texo and DCGag vacc