scholarly journals Regulation of Human Immunodeficiency Virus Replication by 2′,5′-Oligoadenylate-Dependent RNase L

1998 ◽  
Vol 72 (2) ◽  
pp. 1146-1152 ◽  
Author(s):  
Ratan K. Maitra ◽  
Robert H. Silverman
Keyword(s):  
Human Immunodeficiency Virus ◽  
Virus Replication ◽  
Virus Production ◽  
Jurkat Cells ◽  
Alpha Interferon ◽  
Human Immunodeficiency Virus Replication ◽  
Rnase L ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT Activation of RNase L by 2′,5′-linked oligoadenylates (2-5A) is one of the antiviral pathways of interferon action. To determine the involvement of the 2-5A system in the control of human immunodeficiency virus type 1 (HIV-1) replication, a segment of the HIV-1nef gene was replaced with human RNase L cDNA. HIV-1 provirus containing sense orientation RNase L cDNA caused increased expression of RNase L and 500- to 1,000-fold inhibition of virus replication in Jurkat cells for a period of about 2 weeks. Subsequently, a partial deletion of the RNase L cDNA which coincided with increases in virus production occurred. The anti-HIV activity of RNase L correlated with decreases in HIV-1 RNA and with an acceleration in cell death accompanied by DNA fragmentation. Replication of HIV-1 encoding RNase L was also transiently suppressed in peripheral blood lymphocytes (PBL). In contrast, recombinant HIV containing reverse orientation RNase L cDNA caused decreased levels of RNase L, increases in HIV yields, and reductions in the anti-HIV effect of alpha interferon in PBL and in Jurkat cells. To obtain constitutive and continuous expression of RNase L cDNA, Jurkat cells were cotransfected with HIV-1 proviral DNA and with plasmid containing a cytomegalovirus promoter driving expression of RNase L cDNA. The RNase L plasmid suppressed HIV-1 replication by eightfold, while an antisense RNase L construct enhanced virus production by twofold. These findings demonstrate that RNase L can severely impair HIV replication and suggest involvement of the 2-5A system in the anti-HIV effect of alpha interferon.

scholarly journals Conformation of HIV-1 Envelope Governs Rhesus CD4 Usage and Simian-Human Immunodeficiency Virus Replication

mBio ◽  
2022 ◽  
Author(s):  
Geraldine Vilmen ◽  
Anna C. Smith ◽  
Hector Cervera Benet ◽  
Rajni Kant Shukla ◽  
Ross C. Larue ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Animal Model ◽  
Virus Replication ◽  
Rhesus Macaques ◽  
Envelope Glycoproteins ◽  
Human Immunodeficiency Virus Replication ◽  
Preclinical Testing ◽  
Immunodeficiency Virus ◽  
Human Immunodeficiency Viruses ◽  
Hiv 1

Rhesus macaques are a critical animal model for preclinical testing of HIV-1 vaccine and prevention approaches. However, HIV-1 does not replicate in rhesus macaques, and thus, chimeric simian-human immunodeficiency viruses (SHIVs), which encode HIV-1 envelope glycoproteins (Envs), are used as surrogate challenge viruses to infect rhesus macaques for modeling HIV-1 infection.

scholarly journals Genetic Instability of Live, Attenuated Human Immunodeficiency Virus Type 1 Vaccine Strains

1999 ◽  
Vol 73 (2) ◽  
pp. 1138-1145 ◽  
Author(s):  
Ben Berkhout ◽  
Koen Verhoef ◽  
Jeroen L. B. van Wamel ◽  
Nicole K. T. Back
Keyword(s):  
Human Immunodeficiency Virus ◽  
Virus Replication ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Vaccine Strain ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Ltr Promoter ◽  
Hiv 1

ABSTRACT Live, attenuated viruses have been the most successful vaccines in monkey models of human immunodeficiency virus type 1 (HIV-1) infection. However, there are several safety concerns about using such an anti-HIV vaccine in humans, including reversion of the vaccine strain to virulence and recombination with endogenous retroviral sequences to produce new infectious and potentially pathogenic viruses. Because testing in humans would inevitably carry a substantial risk, we set out to test the genetic stability of multiply deleted HIV constructs in perpetuated tissue culture infections. The Δ3 candidate vaccine strain of HIV-1 contains deletions in the viral long terminal repeat (LTR) promoter and the vpr and nef genes. This virus replicates with delayed kinetics, but a profound enhancement of virus replication was observed after approximately 2 months of culturing. Analysis of the revertant viral genome indicated that the three introduced deletions were maintained but a 39-nucleotide sequence was inserted in the LTR promoter region. This insert was formed by duplication of the region encoding three binding sites for the Sp1 transcription factor. The duplicated Sp1 region was demonstrated to increase the LTR promoter activity, and a concomitant increase in the virus replication rate was measured. In fact, duplication of the Sp1 sites increased the fitness of the Δ3 virus (Vpr/Nef/U3) to levels higher than that of the singly deleted ΔVpr virus. These results indicate that deleted HIV-1 vaccine strains can evolve into fast-replicating variants by multiplication of remaining sequence motifs, and their safety is therefore not guaranteed. This insight may guide future efforts to develop more stable anti-HIV vaccines.

Metabolism of 3′-Azido-3′-Deoxythymidine and 3′-Fluoro-3′-Deoxythymidine in Combination in Human Immunodeficiency Virus Infected Lymphoblastoid Cells

1992 ◽  
Vol 3 (3) ◽  
pp. 165-170 ◽  
Author(s):  
S. Cox
Keyword(s):  
Human Immunodeficiency Virus ◽  
Virus Replication ◽  
Cell Types ◽  
Human Immunodeficiency Virus Replication ◽  
Lymphoblastoid Cells ◽  
Synergistic Inhibition ◽  
Immunodeficiency Virus ◽  
Deoxynucleoside Triphosphate ◽  
The Individual

A combination of 3′-azido-3′-deoxythymidine (AZT) with 3′-fluoro-3′-deoxythymidine (FLT) has been shown previously to give synergistic inhibition of human immunodeficiency virus replication and greatly reduced cytotoxicity in vitro. The phosphorylation of the compounds, and their effect upon the natural deoxynucleoside triphosphate pools, were compared in CEM, H9, and HIV-infected H9 lymphoblastoid cells, both for the compounds when used alone and when combined together. Higher levels of FLT triphosphate than AZT triphosphate, and higher levels of AZT monophosphate than FLT monosphosphate, were formed in all cell types. Both compounds were phosphorylated most efficiently in CEM cells, whereas they were least efficiently phosphorylated in infected H9 cells. Owing to competition, the phosphorylation of both analogues was reduced when used in combination, compared to the phosphorylation of the separate compounds. The phosphorylation of the separate compounds was therefore at a maximum and was not increased by combining the compounds. The two compounds competed equally with each other for phosphorylation when used at a ratio of AZT: FLT of 5: 1. Both analogues severely reduced the deoxynucleoside triphosphate pools in uninfected and human immunodeficiency virus-infected H9 cells, but not in CEM cells. The effects of the two compounds were similar to those found when the compounds were combined, and thus H9 cells were shown to be much more sensitive to the effects of the analogues upon deoxynucleoside triphosphate pools than CEM cells were. Thus the synergistic combination of 3′-azido-3′-deoxythymidine and 3′-fluoro-3′-deoxythymidine was shown to have a similar metabolism and a similar effect upon cellular deoxynucleoside triphosphate pools to the individual compounds.

scholarly journals Inhibition of Human Immunodeficiency Virus Replication by a Dual CCR5/CXCR4 Antagonist

2004 ◽  
Vol 78 (23) ◽  
pp. 12996-13006 ◽  
Author(s):  
Katrien Princen ◽  
Sigrid Hatse ◽  
Kurt Vermeire ◽  
Stefano Aquaro ◽  
Erik De Clercq ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Entry ◽  
Mononuclear Cells ◽  
Human Immunodeficiency Virus Replication ◽  
Cxcr4 Antagonist ◽  
Peripheral Blood Mononuclear ◽  
Transfected Cells ◽  
Immunodeficiency Virus ◽  
Intracellular Ca ◽  
Hiv 1

ABSTRACT Here we report that the N-pyridinylmethyl cyclam analog AMD3451 has antiviral activity against a wide variety of R5, R5/X4, and X4 strains of human immunodeficiency virus type 1 (HIV-1) and HIV-2 (50% inhibitory concentration [IC50] ranging from 1.2 to 26.5 μM) in various T-cell lines, CCR5- or CXCR4-transfected cells, peripheral blood mononuclear cells (PBMCs), and monocytes/macrophages. AMD3451 also inhibited R5, R5/X4, and X4 HIV-1 primary clinical isolates in PBMCs (IC50, 1.8 to 7.3 μM). A PCR-based viral entry assay revealed that AMD3451 blocks R5 and X4 HIV-1 infection at the virus entry stage. AMD3451 dose-dependently inhibited the intracellular Ca2+ signaling induced by the CXCR4 ligand CXCL12 in T-lymphocytic cells and in CXCR4-transfected cells, as well as the Ca2+ flux induced by the CCR5 ligands CCL5, CCL3, and CCL4 in CCR5-transfected cells. The compound did not interfere with chemokine-induced Ca2+ signaling through CCR1, CCR2, CCR3, CCR4, CCR6, CCR9, or CXCR3 and did not induce intracellular Ca2+ signaling by itself at concentrations up to 400 μM. In freshly isolated monocytes, AMD3451 inhibited the Ca2+ flux induced by CXCL12 and CCL4 but not that induced by CCL2, CCL3, CCL5, and CCL7. The CXCL12- and CCL3-induced chemotaxis was also dose-dependently inhibited by AMD3451. Furthermore, AMD3451 inhibited CXCL12- and CCL3L1-induced endocytosis in CXCR4- and CCR5-transfected cells. AMD3451, in contrast to the specific CXCR4 antagonist AMD3100, did not inhibit but enhanced the binding of several anti-CXCR4 monoclonal antibodies (such as clone 12G5) at the cell surface, pointing to a different interaction with CXCR4. AMD3451 is the first low-molecular-weight anti-HIV agent with selective HIV coreceptor, CCR5 and CXCR4, interaction.

scholarly journals Potent Synergistic Anti-Human Immunodeficiency Virus (HIV) Effects Using Combinations of the CCR5 Inhibitor Aplaviroc with Other Anti-HIV Drugs

2008 ◽  
Vol 52 (6) ◽  
pp. 2111-2119 ◽  
Author(s):  
Hirotomo Nakata ◽  
Seth M. Steinberg ◽  
Yasuhiro Koh ◽  
Kenji Maeda ◽  
Yoshikazu Takaoka ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Synergistic Effects ◽  
Immunodeficiency Virus ◽  
Approved Drugs ◽  
Hiv Drugs ◽  
Nonparametric Statistical ◽  
Anti Hiv ◽  
Ccr5 Inhibitor ◽  
Hiv 1

ABSTRACT Aplaviroc (AVC), an experimental CCR5 inhibitor, potently blocks in vitro the infection of R5-tropic human immunodeficiency virus type 1 (R5-HIV-1) at subnanomolar 50% inhibitory concentrations. Although maraviroc is presently clinically available, further studies are required to determine the role of CCR5 inhibitors in combinations with other drugs. Here we determined anti-HIV-1 activity using combinations of AVC with various anti-HIV-1 agents, including four U.S. Food and Drug Administration-approved drugs, two CCR5 inhibitors (TAK779 and SCH-C) and two CXCR4 inhibitors (AMD3100 and TE14011). Combination effects were defined as synergistic or antagonistic when the activity of drug A combined with B was statistically greater or less, respectively, than the additive effects of drugs A and A combined and drugs B and B combined by using the Combo method, described in this paper, which provides (i) a flexible choice of interaction models and (ii) the use of nonparametric statistical methods. Synergistic effects against R5-HIV-1Ba-L and a 50:50 mixture of R5-HIV-1Ba-L and X4-HIV-1ERS104pre (HIV-1Ba-L/104pre) were seen when AVC was combined with zidovudine, nevirapine, indinavir, or enfuvirtide. Mild synergism and additivity were observed when AVC was combined with TAK779 and SCH-C, respectively. We also observed more potent synergism against HIV-1Ba-L/104pre when AVC was combined with AMD3100 or TE14011. The data demonstrate a tendency toward greater synergism with AVC plus either of the two CXCR4 inhibitors compared to the synergism obtained with combinations of AVC and other drugs, suggesting that the development of effective CXCR4 inhibitors may be important for increasing the efficacies of CCR5 inhibitors.

scholarly journals Human Immunodeficiency Virus Type 1 Infection of Human Brain-Derived Progenitor Cells

2004 ◽  
Vol 78 (14) ◽  
pp. 7319-7328 ◽  
Author(s):  
Diane M. P. Lawrence ◽  
Linda C. Durham ◽  
Lynnae Schwartz ◽  
Pankaj Seth ◽  
Dragan Maric ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Brain ◽  
Progenitor Cells ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Virus Production ◽  
Tnf Α ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Although cells of monocytic lineage are the primary source of human immunodeficiency virus type 1 (HIV-1) in the brain, other cell types in the central nervous system, including astrocytes, can harbor a latent or persistent HIV-1 infection. In the present study, we examined whether immature, multipotential human brain-derived progenitor cells (nestin positive) are also permissive for infection. When exposed to IIIB and NL4-3 strains of HIV-1, progenitor cells and progenitor-derived astrocytes became infected, with peak p24 levels of 100 to 500 pg/ml at 3 to 6 days postinfection. After 10 days, virus production was undetectable but could be stimulated by the addition of tumor necrosis factor alpha (TNF-α). To bypass limitations to receptor entry, we compared the fate of infection in these cell populations by transfection with the infectious HIV-1 clone, pNL4-3. Again, transfected progenitors and astrocytes produced virus for 7 days but diminished to low levels beyond 8 days posttransfection. During the nonproductive phase, TNF-α stimulated virus production from progenitors as late as 5 weeks posttransfection. Astrocytes produced 5- to 20-fold more infectious virus (27 ng of p24/106 cells) than progenitors at the peak of 3 days posttransfection. Differentiation of infected progenitors toward an astrocyte phenotype increased virus production to levels consistent with infected astrocytes, suggesting a phenotypic difference in viral replication. Using this cell culture system of multipotential human brain-derived progenitor cells, we provide evidence that progenitor cells may be a reservoir for HIV-1 in the brains of AIDS patients.

scholarly journals Mechanism of Action and In Vitro Activity of 1′,3′-Dioxolanylpurine Nucleoside Analogues against Sensitive and Drug-Resistant Human Immunodeficiency Virus Type 1 Variants

1999 ◽  
Vol 43 (10) ◽  
pp. 2376-2382 ◽  
Author(s):  
Zhengxian Gu ◽  
Mark A. Wainberg ◽  
Nghe Nguyen-Ba ◽  
Lucille L’Heureux ◽  
Jean-Marc de Muys ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Mononuclear Cells ◽  
Nucleoside Analogues ◽  
Drug Resistant ◽  
Immunodeficiency Virus ◽  
Blood Mononuclear Cells ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT (−)-β-d-1′,3′-Dioxolane guanosine (DXG) and 2,6-diaminopurine (DAPD) dioxolanyl nucleoside analogues have been reported to be potent inhibitors of human immunodeficiency virus type 1 (HIV-1). We have recently conducted experiments to more fully characterize their in vitro anti-HIV-1 profiles. Antiviral assays performed in cell culture systems determined that DXG had 50% effective concentrations of 0.046 and 0.085 μM when evaluated against HIV-1IIIB in cord blood mononuclear cells and MT-2 cells, respectively. These values indicate that DXG is approximately equipotent to 2′,3′-dideoxy-3′-thiacytidine (3TC) but 5- to 10-fold less potent than 3′-azido-2′,3′-dideoxythymidine (AZT) in the two cell systems tested. At the same time, DAPD was approximately 5- to 20-fold less active than DXG in the anti-HIV-1 assays. When recombinant or clinical variants of HIV-1 were used to assess the efficacy of the purine nucleoside analogues against drug-resistant HIV-1, it was observed that AZT-resistant virus remained sensitive to DXG and DAPD. Virus harboring a mutation(s) which conferred decreased sensitivity to 3TC, 2′,3′-dideoxyinosine, and 2′,3′-dideoxycytidine, such as a 65R, 74V, or 184V mutation in the viral reverse transcriptase (RT), exhibited a two- to fivefold-decreased susceptibility to DXG or DAPD. When nonnucleoside RT inhibitor-resistant and protease inhibitor-resistant viruses were tested, no change in virus sensitivity to DXG or DAPD was observed. In vitro drug combination assays indicated that DXG had synergistic antiviral effects when used in combination with AZT, 3TC, or nevirapine. In cellular toxicity analyses, DXG and DAPD had 50% cytotoxic concentrations of greater than 500 μM when tested in peripheral blood mononuclear cells and a variety of human tumor and normal cell lines. The triphosphate form of DXG competed with the natural nucleotide substrates and acted as a chain terminator of the nascent DNA. These data suggest that DXG triphosphate may be the active intracellular metabolite, consistent with the mechanism by which other nucleoside analogues inhibit HIV-1 replication. Our results suggest that the use of DXG and DAPD as therapeutic agents for HIV-1 infection should be explored.

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