Inhibition Of Human Immunodeficiency Virus-1 Research Articles

Comparative study of HIV-1 inhibition efficiency by carrageenans from red seaweeds family gigartinaceae, Tichocarpaceae and Phyllophoraceae

The efficiency of human immunodeficiency virus-1 (HIV-1) inhibition by sulfated polysaccharides isolated from the various families of red algae of the Far East Pacific coast were studied. The anti-HIV-1 activity of kappa and lambda-carrageenans from Chondrus armatus, original highly sulfated X-carrageenan with low content of 3,6-anhydrogalactose from Tichocarpus crinitus and i/κ–carrageenan with hybrid structure isolated from Ahnfeltiopsis flabelliformis was found. The antiviral action of these polysaccharides and its low-weight oligosaccharide was compared with commercial κ-carrageenan. Here we used the HIV-1-based lentiviral particles and evaluated that these carrageenans in non-toxic concentrations significantly suppress the transduction potential of lentiviral particles pseudotyped with different envelope proteins, targeting cells of neuronal or T-cell origin. The antiviral action of these carrageenans was confirmed using the chimeric replication competent Mo-MuLV (Moloney murine leukemia retrovirus) encoding marker eGFP protein. We found that X-carrageenans from T. crinitus and its low weight derivative and λ-carrageenan from C. armatus effectively suppress the infection caused by retrovirus. The obtained data suggest that the differences in the suppressive effect of carrageenans on the transduction efficiency of HIV-1 based lentiviral particles may be related to the structural features of the studied polysaccharides.

In Silico Studies of Piperazinyl-4-Nitroimidazole Derivatives in the Non-Nucleoside Inhibitory Binding Pocket of Human Immunodeficiency Virus-1-Reverse Transcriptase Enzyme

Human immunodeficiency virus-1 (HIV-1) reverse transcriptase enzyme catalyzes the conversion of viral RNA to DNA. This viral DNA infects a healthy host body, it leads to the production of viral DNA in higher concentrations and leads to a disease called acquired immunodeficiency syndrome; which is a very fatal disease and leads to the development of several other diseases. Therefore, the development of effective inhibitors is required to execute the therapeutic effects against this disease. In this context, in the present study, the docking studies of compounds showing HIV-1 inhibition were performed in the non-nucleoside reverse transcriptase inhibitory binding pocket of the enzyme HIV-1 reverse transcriptase (protein data bank [PDB] ID-1RT2), using AutoDock 4.2.6 and to identify the important pharmacophoric features required for the development of effective non-nucleoside reverse transcriptase inhibitors, pharmacophore analysis was performed. The findings of this study can be used as a valuable tool for identifying and developing potent and effective inhibitors.

Trapping the HIV-1 V3 loop in a helical conformation enables broad neutralization

The third variable (V3) loop on the human immunodeficiency virus 1 (HIV-1) envelope glycoprotein trimer is indispensable for virus cell entry. Conformational masking of V3 within the trimer allows efficient neutralization via V3 only by rare, broadly neutralizing glycan-dependent antibodies targeting the closed prefusion trimer but not by abundant antibodies that access the V3 crown on open trimers after CD4 attachment. Here, we report on a distinct category of V3-specific inhibitors based on designed ankyrin repeat protein (DARPin) technology that reinstitute the CD4-bound state as a key neutralization target with up to >90% breadth. Broadly neutralizing DARPins (bnDs) bound V3 solely on open envelope and recognized a four-turn amphipathic α-helix in the carboxy-terminal half of V3 (amino acids 314–324), which we termed ‘αV3C’. The bnD contact surface on αV3C was as conserved as the CD4 binding site. Molecular dynamics and escape mutation analyses underscored the functional relevance of αV3C, highlighting the potential of αV3C-based inhibitors and, more generally, of postattachment inhibition of HIV-1.

Structural Optimization of 2,3-Dihydro-1H-cyclopenta[b]quinolines Targeting the Noncatalytic RVxF Site of Protein Phosphatase 1 for HIV-1 Inhibition.

Combination antiretroviral therapy (cART) suppresses human immunodeficiency virus-1 (HIV-1) replication but is unable to permanently eradicate HIV-1. Importantly, cART does not target HIV-1 transcription, which is reactivated in latently infected reservoirs, leading to HIV-1 pathogenesis including non-infectious lung, cardiovascular, kidney, and neurodegenerative diseases. To address the limitations of cART and to prevent HIV-1-related pathogenesis, we developed small molecules to target the noncatalytic RVxF-accommodating site of protein phosphatase-1 (PP1) to prevent HIV-1 transcription activation. The PP1 RVxF-accommodating site is critical for the recruitment of regulatory and substrate proteins to PP1. Here, we confirm that our previously developed 1E7-03 compound binds to the PP1 RVxF-accommodating site. Iterative chemical alterations to 1E7-03 furnished a new analogue, HU-1a, with enhanced HIV-1 inhibitory activity and improved metabolic stability compared to 1E7-03. In a Split NanoBit competition assay, HU-1a primarily bound to the PP1 RVxF-accommodating site. In conclusion, our study identified HU-1a as a promising HIV-1 transcription inhibitor and showed that the PP1 RVxF-accommodating site is a potential drug target for the development of novel HIV-1 transcription inhibitors.

Combination antiretroviral therapy and cell-cell spread of wild-type and drug-resistant human immunodeficiency virus-1.

Human immunodeficiency virus-1 (HIV-1) disseminates between T cells either by cell-free infection or by highly efficient direct cell–cell spread. The high local multiplicity that characterizes cell–cell infection causes variability in the effectiveness of antiretroviral drugs applied as single agents. Whereas protease inhibitors (PIs) are effective inhibitors of HIV-1 cell–cell and cell-free infection, some reverse transcriptase inhibitors (RTIs) show reduced potency; however, antiretrovirals are not administered as single agents and are used clinically as combination antiretroviral therapy (cART). Here we explored the efficacy of PI- and RTI-based cART against cell–cell spread of wild-type and drug-resistant HIV-1 strains. Using a quantitative assay to measure cell–cell spread of HIV-1 between T cells, we evaluated the efficacy of different clinically relevant drug combinations. We show that combining PIs and RTIs improves the potency of inhibition of HIV-1 and effectively blocks both cell-free and cell–cell spread. Combining drugs that alone are poor inhibitors of cell–cell spread markedly improves HIV-1 inhibition, demonstrating that clinically relevant combinations of ART can inhibit this mode of HIV-1 spread. Furthermore, comparison of wild-type and drug-resistant viruses reveals that PI- and RTI-resistant viruses have a replicative advantage over wild-type virus when spreading by cell–cell means in the presence of cART, suggesting that in the context of inadequate drug combinations or drug resistance, cell–cell spread could potentially allow for ongoing viral replication.

Baculovirus Infection of Human Monocyte-Derived Dendritic Cells Restricts HIV-1 Replication.

Acquired immune deficiency syndrome (AIDS) is mainly caused by infection with human immunodeficiency virus-1 (HIV-1) and still poses a global threat for which we lack a protective or therapeutic vaccine. Dendritic cells (DCs) play a major role in the onset of HIV infection, providing one of the primary sites of HIV replication, and also act as viral reservoirs in vivo. Previous studies have shown that baculovirus (BV) induces strong host immune responses against infections and malignancies. In this study, we infected human monocyte-derived DCs with recombinant BV (AcCAG-gag) and showed that AcCAG-gag-infected human DCs underwent maturation and produced interferon alpha and other proinflammatory cytokines accompanied by increases in the mRNA and protein expression levels of APOBEC3 (A3A, A3F, and A3G), proteins associated with the inhibition of HIV-1 replication. Surprisingly, HIV-1 inhibition is also observed in human DCs infected with a wild-type BV, as determined by the production of inflammatory cytokines, the expression of A3, and a reduction in the p24 level. Our findings outline the mechanism underlying the inhibition of HIV-1 in BV-infected human DCs and pave the way for the use of BV as an effective tool for immunotherapy against HIV-1.

Identification of light-independent inhibition of human immunodeficiency virus-1 infection through bioguided fractionation of Hypericum perforatum

BackgroundLight-dependent activities against enveloped viruses in St. John's Wort (Hypericum perforatum) extracts have been extensively studied. In contrast, light-independent antiviral activity from this species has not been investigated.ResultsHere, we identify the light-independent inhibition of human immunodeficiency virus-1 (HIV-1) by highly purified fractions of chloroform extracts of H. perforatum. Both cytotoxicity and antiviral activity were evident in initial chloroform extracts, but bioassay-guided fractionation produced fractions that inhibited HIV-1 with little to no cytotoxicity. Separation of these two biological activities has not been reported for constituents responsible for the light-dependent antiviral activities. Antiviral activity was associated with more polar subfractions. GC/MS analysis of the two most active subfractions identified 3-hydroxy lauric acid as predominant in one fraction and 3-hydroxy myristic acid as predominant in the other. Synthetic 3-hydroxy lauric acid inhibited HIV infectivity without cytotoxicity, suggesting that this modified fatty acid is likely responsible for observed antiviral activity present in that fraction. As production of 3-hydroxy fatty acids by plants remains controversial, H. perforatum seedlings were grown sterilely and evaluated for presence of 3-hydroxy fatty acids by GC/MS. Small quantities of some 3-hydroxy fatty acids were detected in sterile plants, whereas different 3-hydroxy fatty acids were detected in our chloroform extracts or field-grown material.ConclusionThrough bioguided fractionation, we have identified that 3-hydroxy lauric acid found in field grown Hypericum perforatum has anti-HIV activity. This novel anti-HIV activity can be potentially developed into inexpensive therapies, expanding the current arsenal of anti-retroviral agents.

Inhibition of human immunodeficiency virus-1 (HIV-1) by β-chemokine analogues in mononuclear cells from HIV-1-infected patients with active tuberculosis

Tuberculosis (TB) enhances human immunodeficiency virus-1 (HIV-1) activity in patients with dual HIV-1/TB infection. Therapies that control augmentations of HIV-1 activity at sites of Mycobacterium tuberculosis (MTB) infection may be useful in inhibition of viral expansion. Regulated upon activation, normal T-cell expressed and secreted (RANTES) analogues (AOP and NNY) are potent in inhibiting the entry of primary HIV-1 isolates into host mononuclear cells. These analogues were used to inhibit MTB-induced HIV-1 entry in blood monunuclear cells (PBMC) from patients with pulmonary TB, and pleural fluid mononuclear cells (PFMC) from patients with pleural TB. PBMC or PFMC were cultured with and without MTB in presence and absence of RANTES analogues. HIV-1 strong stop DNA was assessed by real-time polymerase chain reaction (PCR) as a measure of infection. CCR5 mRNA was assessed by real-time reverse transcription (RT)-PCR and by immunostaining and FACS analysis. HIV-1 infection was induced by MTB in vitro in PBMC from the majority (14 of 20) of HIV-1/TB subjects, and new infection was inhibited by AOP- or NNY-RANTES. HIV-1 infection was also inhibited by these reagents in MTB-induced PFMC from three of three patients with pleural TB. Expression of CCR5 mRNA was significantly induced by MTB in PBMC from patients with pulmonary TB. Further, expression of CCR5 was higher in PFMC compared to PBMC from patients with pleural TB. Also, CCR5 was fourfold higher on CD14(+) pleural mononuclear cells than on CD4(+) lymphocytes. Blocking new HIV-1 infection of mononuclear cells may be useful in control of HIV-1 during dual HIV-1/TB infection.

HIV-1, NFAT, and cyclosporin: immunosuppression for the immunosuppressed?

The human immunodeficiency virus-1 (HIV-1), the cause of AIDS, remains a significant cause of morbidity and mortality throughout the planet. Although reverse transcriptase and protease inhibitors have substantially slowed the virus, viral resistance complicates therapy. Because HIV-1 relies on its host's transcriptional machinery for its own replication, strategies for targeting activation-dependent transcription factors in CD4 T cells are being considered for adjunctive therapy in HIV-1-infected individuals. The nuclear factor of activated T cells (NFAT) family of transcription factors is one such target. On T-cell stimulation, NFAT proteins translocate to the nucleus, where they activate a large number of early response genes, including cytokines such as interleukin-2. Activation and nuclear translocation of NFAT proteins are abrogated by the powerful immunosuppressants cyclosporin A (CsA) and FK506. Over the last several years, various investigators have demonstrated that NFAT proteins bind to the HIV-1 LTR promoter and increase viral transcription. In this report, further evidence supporting a role for NFAT proteins in augmenting HIV-1 transcription is presented. In addition, other mechanisms of HIV-1 inhibition by CsA are reviewed, and the rationale for the use of CsA to treat AIDS is discussed.

Differential Effects of Interleukin-13 on Cytomegalovirus and Human Immunodeficiency Virus Infection in Human Alveolar Macrophages

AbstractAlveolar macrophages, which form a principal line of defense against a variety of pulmonary pathogens, may themselves be infected by viruses like human immunodeficiency virus-1 (HIV-1), which impair their defensive functions. Interleukin-13 (IL-13), a multifunctional cytokine, has been considered for therapeutic use based on its potent inhibition of HIV-1 in these cells. We have further examined the effects of IL-13 on alveolar macrophages under conditions that reflect those seen in acquired immune deficiency syndrome, where this cell type is often infected by the opportunistic pathogen human cytomegalovirus (HCMV). Alveolar macrophages exposed to both HCMV and HIV-1 consistently exhibited higher levels of HIV-1 replication than cells exposed to HIV-1 alone. HIV-1 production was strongly suppressed in alveolar macrophages treated with IL-13 regardless of whether or not the cultures were coinfected with HCMV. However, IL-13 treatment markedly enhanced the expression of HCMV in otherwise latently infected macrophages in a dose dependent manner. These unexpected differential effects of IL-13 on host-virus interactions are important considerations in guiding its potential therapeutic applications.

Inhibition of Human Immunodeficiency Virus-1 (HIV-1) Replication After Transduction of Granulocyte Colony-Stimulating Factor–Mobilized CD34+ Cells From HIV-1–Infected Donors Using Retroviral Vectors Containing Anti–HIV-1 Genes

AbstractTransfer of “anti-HIV-1 genes” into hematopoietic stem cells of human immunodeficiency virus-1 (HIV-1)–infected individuals may be a potent therapeutic approach to render mature cells arising from transduced stem cells resistant to the destructive events associated with HIV-1 infection. To determine the feasibility of gene therapy for acquired immunodeficiency syndrome in individuals already infected with HIV-1, granulocyte colony-stimulating factor mobilized peripheral blood CD34+ cells were isolated from HIV-1–infected individuals and transduced with retroviral vectors containing three different anti–HIV-1-genes: the Rev binding domain of the Rev Responsive Element (RRE decoy) (L-RRE-neo), a double hammerhead ribozyme vector targeted to cleave the tat and rev transcripts (L-TR/TAT-neo), and the trans-dominant mutant of rev (M10) (L-M10-SN). As a control, a vector mediating only neomycin resistance (LN) was used. After 3 days of transduction on allogeneic stroma in the presence of stem cell factor, interleukin-6 (IL-6), and IL-3, the cultures were G418-selected, and then challenged with HIV-1JR-FL and a primary HIV-1 isolate. Compared with the control cultures, the L-RRE-neo–, L-TR/TAT-neo–, and L-M10-SN–transduced cultures displayed up to 1,000-fold inhibition of HIV-1 replication after challenge with HIV-1JR-FL and the primary HIV-1 isolate. Growth of the hematopoietic cells in long-term bone marrow culture was not perturbed by the presence of any of the anti–HIV-1 genes. This study shows that anti–HIV-1 genes can be introduced into CD34+ cells from individuals already infected with HIV-1, and strongly inhibit HIV-1 replication in primary monocytes derived from the CD34+ progenitors.

Dual-target inhibition of HIV-1 in vitro by means of an adeno-associated virus antisense vector.

An adeno-associated virus vector encoding an antisense RNA was used to transduce stable intracellular resistance to human immunodeficiency virus-1 (HIV-1) in human hemopoietic and non-hemopoietic cell lines. The antisense targets are present in all HIV-1 transcripts and include the TAR sequence, which is critical for transcription and virus replication, and the polyadenylation signal. Cell lines expressing antisense RNA showed up to 95 percent inhibition of gene expression directed by the HIV-1 long terminal repeat and greater than 99 percent reduction in infectious HIV-1 production, with no detectable cellular toxicity. Because of their efficient transcription and inability to recombine with HIV-1, adeno-associated virus vectors represent a promising form of anti-retroviral gene therapy.

Inhibition of human immunodeficiency virus 1 (HIV-1) and herpes simplex virus 1 (HSV-1) infectivity with a broad range of lectins

Five lectins with specificity for N- and O-linked oligosaccharides were examined for inhibition of HIV-1 and HSV-1 infectivity in vitro. HIV-1 isolate HTLVIIIB was preincubated with lectin and subsequently inoculated onto MT-4 cells. Lectins specific for N-linked oligosaccharides blocked HIV infection in nanomolar-micromolar concentrations, but no anti-HIV effect was found with the lectin HPA, mainly reacting with O-linked oligosaccharides. HSV-1 infectivity was measured in a plaque reduction assay using Vero cells, and while both N- and O-linked oligosaccharide -specific lectins inhibited HSV-1 infection, the most potent inhibition was found with the lectin HPA. These results indicate that lectins may have a broad antiviral effect on enveloped viruses only limited by types of oligosaccharides present on individual viruses.