anti-HIV Effects Research Articles

Hepatoprotective and in-vitro anti-HIV-1 effect of Alectryon tomentosus F. Muell leaf extract and its phytochemical profile

ObjectivesThis work was designed to evaluate the therapeutic efficacy of Alectryon tomentosus F. Muell leaf extract against CCl 4 -induced hepatic injury in albino rats and anti-HIV effect in vitro. Proximate analysis, phytochemical screening and assay of total flavonoid (TFC) and phenolic contents (TPC), were carried out according to standard methods.Materials and methodsThe TPC and TFC were estimated spectrophotometrically. The median lethal dose (LD 50 ) of the total ethanol extract of A. tomentosus F. Muell leaves was evaluated. The effect on acute HIV-1 infectivity was measured with the syncytium formation assay using AZT (3΄-azido-3΄-deoxythymidine) as a positive control. Moreover, carbon tetrachloride-induced acute hepatic damage was used to evaluate the hepatoprotective effect of the leaves.Results and conclusionProximate analysis of air-dried leaves of A. tomentosus F. Muell revealed 8.3% moisture content, 9.2% total ash, 0.48% water-soluble ash and 2.56% acid-insoluble ash. Preliminary phytochemical screening revealed that the dried powdered leaves of A. tomentosus F. Muell are rich in carbohydrates and/or glycosides, volatile constituents, sterols and/or triterpenes and tannins; however, flavonoids (free and combined) and coumarins are present in a lesser concentration. Alkaloids, saponins, cardiac glycosides and anthraquinones are absent. The evaluated TPC was 71.59 mg gallic acid equivalent/g dry weight, whereas TFC was 63.64 mg quercetin equivalent/g plant dry weight. The median lethal dose (LD 50 ) of the total ethanol extract was found to be 9.2 g/kg body weight, indicating the safety of the leaves of the plant. In carbon tetrachloride-induced acute hepatic damage model, the methylene chloride extract showed the highest protection percentage as shown by reduction in the level of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels, followed by aqueous extract. These may be attributed to their phenolic and flavonoidal content. The anti-HIV-1 activity was assessed by evaluating syncytium formation. The results showed that the extract was minimally toxic and showed a weak anti-HIV-1 activity in comparison with AZT.

Thiolated pyrimidine nucleotides may interfere thiol groups concentrated at lipid rafts of HIV-1 infected cells.

Upon HIV infection, cells become activated and cell surface thiols are present in increased number. Earlier we demonstrated in vitro anti-HIV effect of thiolated pyrimidine nucleotide UD29, which interferes thiol function. To further analyse the redox processes required for HIV-1 entry and infection, toxicity assays were performed using HIV-1 infected monolayer HeLaCD4-LTR/ β-gal cells and suspension H9 T cells treated with several thiolated nucleotide derivatives of UD29. Selective cytotoxicity of thiolated pyrimidines on HIV-1 infected cells were observed. Results indicate that thiolated pyrimidine derivates may interfere with -SH (thiol) groups concentrated in lipid rafts of cell membrane and interacts HIV-1 infected (activated) cells resulting in a selective cytotoxicity of HIV-1 infected cells, and reducing HIV-1 entry.

Host and viral determinants for MxB restriction of HIV-1 infection.

BackgroundInterferon-induced cellular proteins play important roles in the host response against viral infection. The Mx family of dynamin-like GTPases, which include MxA and MxB, target a wide variety of viruses. Despite considerable evidence demonstrating the breadth of antiviral activity of MxA, human MxB was only recently discovered to specifically inhibit lentiviruses. Here we assess both host and viral determinants that underlie MxB restriction of HIV-1 infection.ResultsHeterologous expression of MxB in human osteosarcoma cells potently inhibited HIV-1 infection (~12-fold), yet had little to no effect on divergent retroviruses. The anti-HIV effect manifested as a partial block in the formation of 2-long terminal repeat circle DNA and hence nuclear import, and we accordingly found evidence for an additional post-nuclear entry block. A large number of previously characterized capsid mutations, as well as mutations that abrogated integrase activity, counteracted MxB restriction. MxB expression suppressed integration into gene-enriched regions of chromosomes, similar to affects observed previously when cells were depleted for nuclear transport factors such as transportin 3. MxB activity did not require predicted GTPase active site residues or a series of unstructured loops within the stalk domain that confer functional oligomerization to related dynamin family proteins. In contrast, we observed an N-terminal stretch of residues in MxB to harbor key determinants. Protein localization conferred by a nuclear localization signal (NLS) within the N-terminal 25 residues, which was critical, was fully rescuable by a heterologous NLS. Consistent with this observation, a heterologous nuclear export sequence (NES) abolished full-length MxB activity. We additionally mapped sub-regions within amino acids 26–90 that contribute to MxB activity, finding sequences present within residues 27–50 particularly important.ConclusionsMxB inhibits HIV-1 by interfering with minimally two steps of infection, nuclear entry and post-nuclear trafficking and/or integration, without destabilizing the inherent catalytic activity of viral preintegration complexes. Putative MxB GTPase active site residues and stalk domain Loop 4 -- both previously shown to be necessary for MxA function -- were dispensable for MxB antiviral activity. Instead, we highlight subcellular localization and a yet-determined function(s) present in the unique MxB N-terminal region to be required for HIV-1 restriction.Electronic supplementary materialThe online version of this article (doi:10.1186/s12977-014-0090-z) contains supplementary material, which is available to authorized users.

Autophagy restricts HIV-1 infection by selectively degrading Tat in CD4+ T lymphocytes.

Autophagy is a ubiquitous mechanism involved in the lysosomal-mediated degradation of cellular components when they are engulfed in vacuoles called autophagosomes. Autophagy is also recognized as an important regulator of the innate and adaptive immune responses against numerous pathogens, which have, therefore, developed strategies to block or use the autophagy machinery to their own benefit. Upon human immunodeficiency virus type 1 (HIV-1) infection, viral envelope (Env) glycoproteins induce autophagy-dependent apoptosis of uninfected bystander CD4(+) T lymphocytes, a mechanism likely contributing to the loss of CD4(+) T cells. In contrast, in productively infected CD4(+) T cells, HIV-1 is able to block Env-induced autophagy in order to avoid its antiviral effect. To date, nothing is known about how autophagy restricts HIV-1 infection in CD4(+) T lymphocytes. Here, we report that autophagy selectively degrades the HIV-1 transactivator Tat, a protein essential for viral transcription and virion production. We demonstrated that this selective autophagy-mediated degradation of Tat relies on its ubiquitin-independent interaction with the p62/SQSTM1 adaptor. Taken together, our results provide evidence that the anti-HIV effect of autophagy is specifically due to the degradation of the viral transactivator Tat but that this process is rapidly counteracted by the virus to favor its replication and spread. Autophagy is recognized as one of the most ancient and conserved mechanisms of cellular defense against invading pathogens. Cross talk between HIV-1 and autophagy has been demonstrated depending on the virally challenged cell type, and HIV-1 has evolved strategies to block this process to replicate efficiently. However, the mechanisms by which autophagy restricts HIV-1 infection remain to be elucidated. Here, we report that the HIV-1 transactivator Tat, a protein essential for viral replication, is specifically degraded by autophagy in CD4(+) T lymphocytes. Both Tat present in infected cells and incoming Tat secreted from infected cells are targeted for autophagy degradation through a ubiquitin-independent interaction with the autophagy receptor p62/SQSTM1. This study is the first to demonstrate that selective autophagy can be an antiviral process by degrading a viral transactivator. In addition, the results could help in the design of new therapies against HIV-1 by specifically targeting this mechanism.

Dynamic interaction between astrocytes and infiltrating PBMCs in context of neuroAIDS.

HIV-mediated neuropathogenesis is a multifaceted process involving several players, including resident brain cells (neurons, astrocytes, and microglia) and infiltrating cells [peripheral blood mononuclear cells (PBMCs)]. We evaluated the dynamic interaction between astrocytes and infiltrating PBMCs as it impacts HIV in the CNS. We demonstrate that human primary-derived astrocytes (PDAs) predominantly secrete Wnt 1, 2b, 3, 5b, and 10b. Wnts are small secreted glycoproteins that initiate either β-catenin-dependent or independent signal transduction. The Wnt pathway plays a vital role in the regulation of CNS activities including neurogenesis, neurotransmitter release, synaptic plasticity, and memory consolidation. We show that HIV infection of PDAs altered astrocyte Wnt profile by elevating Wnts 2b and 10b. Astrocyte conditioned media (ACM) inhibited HIV replication in PBMCs by 50%. Removal of Wnts from ACM abrogated its ability to suppress HIV replication in PBMCs. Inversely, PBMCs supernatant activated PDAs, as demonstrated by a 10-fold increase in HLA-DR and a 5-fold increase in IFNγ expression, and enhanced astrocyte susceptibility to HIV by 2-fold, which was mediated by IFNγ in a Stat-3-dependent manner. Collectively, these data demonstrate a dynamic interaction between astrocytes and PBMCs, whereby astrocyte-secreted Wnts exert an anti-HIV effect on infected PBMCs and PBMCs, in turn, secrete IFNγ that enhance astrocyte susceptibility to productive HIV infection and mediate their activation.

Self-assembled micellar nanocomplexes comprising green tea catechin derivatives and protein drugs for cancer therapy.

In designing drug carriers, the drug-to-carrier ratio is an important consideration because using high quantities of carriers can cause toxicity resulting from poor metabolism and elimination of the carriers1. However, these issues would be of less concern if both the drug and carrier possess therapeutic effects. (-)-Epigallocatechin-3-O-gallate (EGCG), which is a major ingredient of green tea, has been shown to possess anticancer effects2-7, anti-HIV effects8, neuroprotective effects9, DNA-protective effects10, etc. Here we show that sequential self-assembly of the EGCG derivative with anticancer proteins forms stable micellar nanocomplexes (MNCs), which have greater anticancer effects in vitro and in vivo than the free protein. The MNC is obtained by complexation of oligomerized EGCG with the anticancer protein, Herceptin, to form the core, followed by complexation of poly(ethylene glycol)-EGCG to form the shell. When injected into mice, the Herceptin-loaded MNC showed better tumour selectivity and growth reduction, and longer blood-half-life than free Herceptin.

Humic Acids (HA) Strongly Potentiate Anti-HIV Effects of AZT, Griffithsin, and Cyanovirin

AIDS Research and Human RetrovirusesVol. 30, No. S1 Evaluation of Novel Compounds in Cell-Based SystemsHumic Acids (HA) Strongly Potentiate Anti-HIV Effects of AZT, Griffithsin, and CyanovirinEduard Karamov, Galina Kornilaeva, Kabamba Alexandre, Barry O'Keefe, Christiane Moog, Ian McGowan, Gustavo Doncel, Irina Zalenskaya, Ali Turgiev, and Alexander TatarintsevEduard KaramovIvanovsky Institute of Virology, Moscow, Russian FederationImmunomica LLC, Moscow, Russian FederationSearch for more papers by this author, Galina KornilaevaIvanovsky Institute of Virology, Moscow, Russian FederationSearch for more papers by this author, Kabamba AlexandreCenter for Cancer Research, National Cancer Institute, Frederick, MD, United StatesSearch for more papers by this author, Barry O'KeefeCenter for Cancer Research, National Cancer Institute, Frederick, MD, United StatesSearch for more papers by this author, Christiane MoogStrasbourg University, Strasbourg, FranceSearch for more papers by this author, Ian McGowanUniversity of Pittsburgh Medical Center and Magee-Women Research Institute, Pittsburgh, PA, United StatesSearch for more papers by this author, Gustavo DoncelEastern Virginia Medical School, CONRAD, Norfolk, VA, United StatesSearch for more papers by this author, Irina ZalenskayaEastern Virginia Medical School, CONRAD, Norfolk, VA, United StatesSearch for more papers by this author, Ali TurgievImmunomica LLC, Moscow, Russian FederationSearch for more papers by this author, and Alexander TatarintsevImmunomica LLC, Moscow, Russian FederationSearch for more papers by this authorPublished Online:30 Oct 2014https://doi.org/10.1089/aid.2014.5441.abstractAboutSectionsView articleView Full TextPDF/EPUB Permissions & CitationsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View article"Humic Acids (HA) Strongly Potentiate Anti-HIV Effects of AZT, Griffithsin, and Cyanovirin." AIDS Research and Human Retroviruses, 30(S1), p. A204FiguresReferencesRelatedDetails Volume 30Issue S1Oct 2014 InformationCopyright 2014, Mary Ann Liebert, Inc.To cite this article:Eduard Karamov, Galina Kornilaeva, Kabamba Alexandre, Barry O'Keefe, Christiane Moog, Ian McGowan, Gustavo Doncel, Irina Zalenskaya, Ali Turgiev, and Alexander Tatarintsev.Humic Acids (HA) Strongly Potentiate Anti-HIV Effects of AZT, Griffithsin, and Cyanovirin.AIDS Research and Human Retroviruses.Oct 2014.A204-A204.http://doi.org/10.1089/aid.2014.5441.abstractPublished in Volume: 30 Issue S1: October 30, 2014PDF download

Betulinic Acid as a Potent and Complex Antitumor Phytochemical: A Minireview

Betulinic acid (BA), a natural compound with a lupan skeleton, has been highly investigated in the past decade for a plethora of beneficial properties, including anti-cancer, anti-inflammatory, anti-angiogenic, immune-modulatory, and anti-HIV effects. In particular, BA has been reported to be effective in vitro against tumor cell lines of different origins, and also in vivo, in animal models of cancer. The best characterized mechanism of its antitumor effect consists of triggering apoptosis via the mitochondrial pathway. BA has also an anti-metastatic effect via the prevention of the epithelial-to-mesencymal transition in highly aggressive melanoma cells. Furthermore, in the same model, BA is able to counteract the pro-invasive potential of the pro-tumoral protein neutrophil gelatinaseassociated lipocalin. The present review addresses the current state of knowledge regarding the anti-tumor effects of betulinic acid, a potent chemotherapeutic agent.

The CD8-Derived Chemokine XCL1/Lymphotactin Is a Conformation-Dependent, Broad-Spectrum Inhibitor of HIV-1

CD8+ T cells play a key role in the in vivo control of HIV-1 replication via their cytolytic activity as well as their ability to secrete non-lytic soluble suppressive factors. Although the chemokines that naturally bind CCR5 (CCL3/MIP-1α, CCL4/MIP- 1β, CCL5/RANTES) are major components of the CD8-derived anti-HIV activity, evidence indicates the existence of additional, still undefined, CD8-derived HIV-suppressive factors. Here, we report the characterization of a novel anti-HIV chemokine, XCL1/lymphotactin, a member of the C-chemokine family that is produced primarily by activated CD8+ T cells and behaves as a metamorphic protein, interconverting between two structurally distinct conformations (classic and alternative). We found that XCL1 inhibits a broad spectrum of HIV-1 isolates, irrespective of their coreceptor-usage phenotype. Experiments with stabilized variants of XCL1 demonstrated that HIV-1 inhibition requires access to the alternative, all-β conformation, which interacts with proteoglycans but does not bind/activate the specific XCR1 receptor, while the classic XCL1 conformation is inactive. HIV-1 inhibition by XCL1 was shown to occur at an early stage of infection, via blockade of viral attachment and entry into host cells. Analogous to the recently described anti-HIV effect of the CXC chemokine CXCL4/PF4, XCL1-mediated inhibition is associated with direct interaction of the chemokine with the HIV-1 envelope. These results may open new perspectives for understanding the mechanisms of HIV-1 control and reveal new molecular targets for the design of effective therapeutic and preventive strategies against HIV-1.

Estrogen like agents as anticancer drugs : Theory , synthesis and analysis

A simple and suitable synthetic route is reported for the formation of new 2a-triazolylcholestane derivatives. The scheme involves transformation of the starting cholestanone to the corresponding azido compound and efficient conversions of 2a-azido-5a-cholestan-3-one (3).The antiproliferative activities of the synthesized 2-triazolyl-3-ketones against three human cancer cell lines were screened. but, the result was not so acceptable in cell-growth inhibition. Introduction there are a number of reactions that fulfill the Sharpless criteria, the Cu-catalysed azide-alkyne 1,3dipolar cycloaddition (CuAAC) is perhaps the best-known example of this group. The 1,2,3-triazole unit has a several advantageous properties, like high chemical stability, good hydrogen-bond-accepting ability, a strong dipole moment and an aromatic character.Therefore a number of compounds containing 1,2,3-triazoles have been reported to exert biological activity, including antibacterial, antiallergic and anti-HIV effects. We tried to synthesis of steroidal heterocycles, and we have tried to develop an effective route for the production of various 2-triazolyl derivatives of cholestanone, 4c,4g, it was decided to screen these compounds in vitro for their activities against a panel of three human cancer cell lines (HeLa, MCF7 and A431). Herein, we hope we can describe the details of the synthesis of 2a-azido-5a-cholestan-3-one (3), followed by Huisgen 1,3-dipolar cycloaddition with different terminal alkynes and subsequent reduction of the resultant triazolyl ketones. International Journal of Scientific & Engineering Research (IJSER) ISSN 2229-5518 DOI : 10.14299/ijser.thesis.2013.12

A candidate anti-HIV reservoir compound, auranofin, exerts a selective ‘anti-memory’ effect by exploiting the baseline oxidative status of lymphocytes

Central memory (TCM) and transitional memory (TTM) CD4+ T cells are known to be the major cellular reservoirs for HIV, as these cells can harbor a transcriptionally silent form of viral DNA that is not targeted by either the immune system or current antiretroviral drug regimens. In the present study, we explored the molecular bases of the anti-HIV reservoir effects of auranofin (AF), a pro-oxidant gold-based drug and a candidate compound for a cure of AIDS. We here show that TCM and TTM lymphocytes have lower baseline antioxidant defenses as compared with their naive counterpart. These differences are mirrored by the effects exerted by AF on T-lymphocytes: AF was able to exert a pro-differentiating and pro-apoptotic effect, which was more pronounced in the memory subsets. AF induced an early activation of the p38 mitogen-activated protein kinase (p38 MAPK) followed by mitochondrial depolarization and a final burst in intracellular peroxides. The pro-differentiating effect was characterized by a downregulation of the CD27 marker expression. Interestingly, AF-induced apoptosis was inhibited by pyruvate, a well-known peroxide scavenger, but pyruvate did not inhibit the pro-differentiating effect of AF, indicating that the pro-apoptotic and pro-differentiating effects involve different pathways. In conclusion, our results demonstrate that AF selectively targets the TCM/TTM lymphocyte subsets, which encompass the HIV reservoir, by affecting redox-sensitive cell death pathways.

Pre-clinical Modeling of CCR5 Knockout in Human Hematopoietic Stem Cells by Zinc Finger Nucleases Using Humanized Mice

Genetic strategies to block expression of CCR5, the major co-receptor of human immunodeficiency virus type 1 (HIV-1), are being developed as anti-HIV therapies. For example, human hematopoietic stem/precursor cells (HSPC) can be modified by the transient expression of CCR5-targeted zinc finger nucleases (ZFNs) to generate CCR5-negative cells, which could then give rise to HIV-resistant mature CD4(+) T cells following transplantation into patients. The safety and anti-HIV effects of such treatments can be evaluated by transplanting ZFN-treated HSPC into immunodeficient mice, where the extent of human cell engraftment, lineage differentiation and anti-HIV activity arising from the engineered HSPC can be examined. In this way, humanized mice are providing a powerful small animal model for pre-clinical studies of novel anti-HIV therapies.

Anti-HIV Activity of Human Defensin 5 in Primary CD4+ T Cells under Serum-Deprived Conditions Is a Consequence of Defensin-Mediated Cytotoxicity

BackgroundWe have previously shown that human defensin 5 (HD5) promotes HIV infectivity in both primary CD4+ T cells and HeLa cells expressing CD4 and CCR5. HD5 is induced in response to sexually transmitted infections (STIs) such as Chlamydia trachomatis and Neisseria gonorrhoeae, suggesting it plays a role in STI-mediated enhancement of HIV transmission. In contrast to our findings, a recent study reports that HD5 has an anti-HIV effect in primary CD4+ T cells under serum-deprived conditions. To resolve these apparently contradictory observations, we investigated experimental parameters that might contribute to contrasting effects of HD5.ResultsSerum-deprived culture conditions were associated with anti-HIV activity. In contrast to the dependence of the HIV enhancing effect on HD5 structure, the anti-HIV activity in serum-deprived primary CD4+ T cells was independent of HD5 structure as the linear peptide [Abu] HD5 exhibited similar anti-HIV activity. Under serum deprived conditions, HD5 blocked CD4-receptor-independent HIV-1vsv infection before or after viral entry. We found that HD5 and its linear form induced significant cell death in primary CD4+ T cells under serum-deprived culture conditions. HD5-mediated apoptosis was observed as early as 2 h after addition of defensins to serum-deprived primary CD4+ T cells. In contrast to primary CD4+ T cells, HD5 did not induce cytotoxicity and promote HIV infectivity of HeLa-CD4-CCR5 cells under serum-deprived conditions.ConclusionsThese results indicate that under serum-deprived culture conditions HD5 is toxic for primary CD4+ T cells, warranting caution in data interpretation.

Anti-HIV Effect of Liposomes Bearing CXCR4 Receptor Antagonist N15P

Purpose : To evaluate lymphatic system targeting and inhibitory ability of N15P nano-liposomal preparation (naLipo-N15P) of CXCR4 receptor antagonist in HIV infection. Methods: Chemotactic and chemotaxic inhibition activity assays were used to analyze the biological activity of naLipo-N15P. The anti-HIV potential of NaLipo-N15P in vitro was evaluated when NaLipo- N15P combined with the peripheral blood mononuclear cells of Macaca fascicularis which carry the Simian immunodeficiency virus. Furthermore, the anti-HIV potential in vivo of NaLipo-N15P was evaluated by the plasma concentration and tissue distribution (Ki) Results: The half-maximal inhibitory concentration of naLipo-N15P binding to CXCR4 as an antagonist in competition with SDF-1α was 1.89 pM while Ki was 2.4 pM. Viral load was 289 ± 45. NaLipo- N15P majorly accumulated in liver and spleen. Conclusion: When N15P is encapsulated into nano-liposomes, it not only retains specific binding to CXCR4 and facilitates cell-type-specific targeting of nano-liposomes to PBMCs with high CXCR4 expression, but also shows enhanced anti-HIV effect. Therefore, we propose that naLipo-N15P as a CXCR4 antagonist will play an important role in inflammation and blocking of HIV infection. Keywords : Antagonist, CXCR4, Liposomes, Receptor, Inflammation, HIV

Methamphetamine Inhibits Toll-Like Receptor 9-Mediated Anti-HIV Activity in Macrophages

Toll-like receptor 9 (TLR9) is one of the key sensors that recognize viral infection/replication in the host cells. Studies have demonstrated that methamphetamine (METH) dysregulated host cell innate immunity and facilitated HIV infection of macrophages. In this study, we present new evidence that METH suppressed TLR9-mediated anti-HIV activity in macrophages. Activation of TLR9 by its agonist CpG-ODN 2216 inhibits HIV replication, which was demonstrated by increased expression of TLR9, interferon (IFN)-α, IFN regulatory factor-7 (IRF-7), myeloid differentiation factor 88 (MyD88), and myxovirus resistance gene A (MxA) in macrophages. However, METH treatment of macrophages greatly compromised the TLR9 signaling-mediated anti-HIV effect and inhibited the expression of TLR9 downstream signaling factors. Dopamine D1 receptor (D1R) antagonists (SCH23390) could block METH-mediated inhibition of anti-HIV activity of TLR9 signaling. Investigation of the underlying mechanisms of the METH action showed that METH treatment selectively down-regulated the expression of TLR9 on macrophages, whereas it had little effect on the expression of other TLRs. Collectively, our results provide further evidence that METH suppresses host cell innate immunity against HIV infection by down-regulating TLR9 expression and its signaling-mediated antiviral effect in macrophages.

Immune activation of human brain microvascular endothelial cells inhibits HIV replication in macrophages

AbstractThere is limited information about the role of blood-brain barrier (BBB) endothelial cells (ECs) in the central nervous system (CNS) and their innate immunity against HIV. We examined whether brain ECs can be immunologically activated to produce antiviral factors that inhibit HIV replication in macrophages. Human brain microvascular ECs expressed functional toll-like receptor 3 (TLR3) that could be activated by polyinosinic-polycytidylic acid (PolyI:C), resulting in the induction of endogenous interferon-β (IFN-β) and IFN-λ. The TLR3 activation of ECs also induced the phosphorylation of interferon regulatory transcription factor 3 (IRF3) and IRF7, the key regulators of IFN signaling pathway. When supernatant (SN) of PolyI:C-activated EC cultures was applied to infected macrophage cultures, HIV replication was significantly suppressed. This SN action of ECs on HIV was mediated through both IFN-β and IFN-λ because antibodies to their receptors could neutralize the SN-mediated anti-HIV effect. The role of IFNs in EC-mediated anti-HIV activity is further supported by the observation that treatment with SN from EC cultures induced the expression of IFN-stimulated genes (ISGs: ISG56, OAS-1, and MxA) in macrophages. These observations indicate that brain microvascular ECs may be a key regulatory bystander, playing a crucial role in the BBB innate immunity against HIV infection.

Gardiquimod: A Toll-Like Receptor-7 Agonist That Inhibits HIV Type 1 Infection of Human Macrophages and Activated T Cells

Immune response modifiers are being studied as therapeutic agents for viral infections and cancer. These molecules include agonists for the Toll-like receptors (TLR), a family of innate immune receptors. TLR7 and 8, located in cellular endosomes, bind single-stranded RNA characteristic of viral genomes, and trigger intracellular signaling pathways that induce inflammatory cytokines and antiviral innate immune factors. We studied the anti-HIV-1 effects of gardiquimod, a specific TLR7 agonist when used at concentrations below 10 μM, in macrophages and activated peripheral blood mononuclear cells (PBMCs). Gardiquimod, added prior to or within 2 days after infection with X4, R5, or dual-tropic (R5/X4) strains of HIV-1, significantly reduced infection in these cells. Cocultures of activated PBMCs added to gardiquimod-treated and HIV-1-exposed macrophages demonstrated minimal HIV-1 replication for up to 10 days, suggesting that gardiquimod inhibited activated PBMCs viral amplification from HIV-1-exposed macrophages. Gardiquimod treatment of both activated PBMCs and macrophages induced interferon-alpha (IFN-α) transcription within hours of addition, and sustained IFN-α protein secretion for several days. Treatment of cells with a peptide inhibitor to the MyD88 adaptor protein blocked the induction of IFN-α by gardiquimod, and partially reversed the anti-HIV effects in activated PBMCs. Blocking the IFN-α receptor with a neutralizing antibody also reduced the anti-HIV effect of gardiquimod. Gardiquimod inhibited HIV-1 reverse transcriptase, an early step in the life cycle of HIV-1. These findings suggest that gardiquimod, functioning as both an immune system modifier and a reverse transcriptase inhibitor, could be developed as a novel therapeutic agent to block systemic and mucosal transmission of HIV-1.

Combinatorial anti-HIV gene therapy: using a multipronged approach to reach beyond HAART

The 'Berlin Patient', who maintains suppressed levels of HIV viremia in the absence of antiretroviral therapy, continues to be a standard bearer in HIV eradication research. However, the unique circumstances surrounding his functional cure are not applicable to most HIV(+) patients. To achieve a functional or sterilizing cure in a greater number of infected individuals worldwide, combinatorial treatments, targeting multiple stages of the viral life cycle, will be essential. Several anti-HIV gene therapy approaches have been explored recently, including disruption of the C-C chemokine receptor 5 (CCR5) and CXC chemokine receptor 4 (CXCR4) coreceptor loci in CD4(+) T cells and CD34(+) hematopoietic stem cells. However, less is known about the efficacy of these strategies in patients and more relevant HIV model systems such as non-human primates (NHPs). Combinatorial approaches, including genetic disruption of integrated provirus, functional enhancement of endogenous restriction factors and/or the use of pharmacological adjuvants, could amplify the anti-HIV effects of CCR5/CXCR4 gene disruption. Importantly, delivering gene disruption molecules to genetic sites of interest will likely require optimization on a cell type-by-cell type basis. In this review, we highlight the most promising gene therapy approaches to combat HIV infection, methods to deliver these therapies to hematopoietic cells and emphasize the need to target viral replication pre- and post-entry to mount a suitably robust defense against spreading infection.

Short Communication Efficient isolation of high-quality RNA from lotus Nelumbo nucifera ssp nucifera tissues

Nelumbo nucifera is widely used as food, as an ornamental, in medicine, and as packing material; it is also reported to have anti-HIV effects and antioxidant capacity. We sought an improved method for extracting high-quality total RNA from different tissues of N. nucifera. Four methods for RNA extraction were assessed for their ability to recover high-quality RNA applicable for evaluation of polyphenol oxidase (PPO) gene expression profiles. The recovery and quality of the RNA obtained from five different tissues by the best CTAB-LiCl method were evaluated through UV light absorbance. Both A(260)/A(280) and A(260)/A(230) absorbance ratios were more than 2.0; the yield ranged from 59.87 to 163.75 μg/g fresh weight. The brightness of the 28S band was approximately twice that of 18S; the latter was also considered as high-quality RNA. The PPO gene fragment (606 bp) was successfully amplified by RT-PCR, demonstrating the integrity of the isolated RNA. The relative expression levels of the PPO gene based on RT-PCR in five tissues of lotus were: rhizome buds (2.66), young leaves (2.42), fresh cut rhizome (2.02), petals (1.80), and petiole (1.65), using housekeeping gene β-actin as an internal control. We concluded that the total RNA isolated by this protocol is of sufficient quality for molecular applications.

Enhanced Anti-HIV Efficacy of Indinavir After Inclusion in CD4-Targeted Lipid Nanoparticles

Combination drug therapy has reduced plasma HIV to undetectable levels; however, drug-sensitive virus persists in patients' lymphoid tissue. We have reported significant lymphoid tissue drug localization with indinavir-associated lipid nanoparticles (LNPs). Our current objective is to evaluate whether additional enhancement is achievable by targeting these particles to CD4-HIV host cells. We characterized 2 peptide-coated (CD4-BP2 and CD4-BP4) drug-associated LNPs and demonstrated CD4-cell specificity. Drug-associated LNPs expressing polyethyleneglycol were exposed on HIV-2-infected cells under dynamic conditions that emulated lymph node physiology for 15, 30, and 60 minutes at concentrations from 0 to 25 μM and evaluated for antiviral activity and cell-associated drug concentrations. The specificity of CD4-mediated enhancement of indinavir LNPs antiviral activity was evaluated by blocking with anti-CD4 antibody. Inclusion of CD4-binding peptides on LNPs enhanced antiviral activity for all incubation conditions, compared with control particles or soluble drug (eg, 60 minutes exposure, EC50 = 0.12-0.13 vs. 0.46 μM for targeted nanoparticles vs. soluble drug). The CD4-BP4 peptide exhibited higher efficiency in eliciting antiviral activity than CD4-BP2-coated particles (EC50 = 7.5 μM vs. >25 μM at 15 minutes drug exposure). This enhancement seems to be driven by CD4 availability and cell-associated indinavir concentrations, as blocking of CD4 significantly ablated indinavir efficacy in targeted particles and indinavir concentrations reflected the observed anti-HIV activity. We constructed CD4-targeted LNPs that provide selective binding and efficient delivery of indinavir to CD4-HIV host cells. Inclusion of polyethyleneglycol in LNPs would minimize immune recognition of peptides. The enhancement of anti-HIV effects is effective even under limited time exposure.