scholarly journals Cocrystal Structures of Antibody N60-i3 and Antibody JR4 in Complex with gp120 Define More Cluster A Epitopes Involved in Effective Antibody-Dependent Effector Function against HIV-1

2015 ◽  
Vol 89 (17) ◽  
pp. 8840-8854 ◽  
Author(s):  
Neelakshi Gohain ◽  
William D. Tolbert ◽  
Priyamvada Acharya ◽  
Lei Yu ◽  
Tongyun Liu ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Monoclonal Antibody ◽  
Antiretroviral Drugs ◽  
Effector Function ◽  
Effector Functions ◽  
Immunodeficiency Virus ◽  
Cluster A ◽  
Definition Of ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACTAccumulating evidence indicates a role for Fc receptor (FcR)-mediated effector functions of antibodies, including antibody-dependent cell-mediated cytotoxicity (ADCC), in prevention of human immunodeficiency virus type 1 (HIV-1) acquisition and in postinfection control of viremia. Consequently, an understanding of the molecular basis for Env epitopes that constitute effective ADCC targets is of fundamental interest for humoral anti-HIV-1 immunity and for HIV-1 vaccine design. A substantial portion of FcR effector function of potentially protective anti-HIV-1 antibodies is directed toward nonneutralizing, transitional, CD4-inducible (CD4i) epitopes associated with the gp41-reactive region of gp120 (cluster A epitopes). Our previous studies defined the A32-like epitope within the cluster A region and mapped it to the highly conserved and mobile layers 1 and 2 of the gp120 inner domain within the C1-C2 regions of gp120. Here, we elucidate additional cluster A epitope structures, including an A32-like epitope, recognized by human monoclonal antibody (MAb) N60-i3, and a hybrid A32-C11-like epitope, recognized by rhesus macaque MAb JR4. These studies define for the first time a hybrid A32-C11-like epitope and map it to elements of both the A32-like subregion and the seven-layered β-sheet of the gp41-interactive region of gp120. These studies provide additional evidence that effective antibody-dependent effector function in the cluster A region depends on precise epitope targeting—a combination of epitope footprint and mode of antibody attachment. All together these findings help further an understanding of how cluster A epitopes are targeted by humoral responses.IMPORTANCEHIV/AIDS has claimed the lives of over 30 million people. Although antiretroviral drugs can control viral replication, no vaccine has yet been developed to prevent the spread of the disease. Studies of natural HIV-1 infection, simian immunodeficiency virus (SIV)- or simian-human immunodeficiency virus (SHIV)-infected nonhuman primates (NHPs), and HIV-1-infected humanized mouse models, passive transfer studies in infants born to HIV-infected mothers, and the RV144 clinical trial have linked FcR-mediated effector functions of anti-HIV-1 antibodies with postinfection control of viremia and/or blocking viral acquisition. With this report we provide additional definition of the molecular determinants for Env antigen engagement which lead to effective antibody-dependent effector function directed to the nonneutralizing CD4-dependent epitopes in the gp41-reactive region of gp120. These findings have important implications for the development of an effective HIV-1 vaccine.

scholarly journals Natural Products with Inhibitory Activity against Human Immunodeficiency Virus Type 1

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Maria S. Serna-Arbeláez ◽  
Laura Florez-Sampedro ◽  
Lina P. Orozco ◽  
Katherin Ramírez ◽  
Elkin Galeano ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Natural Products ◽  
Therapeutic Potential ◽  
Low Cost ◽  
Antiviral Agent ◽  
Complementary Therapy ◽  
Antiretroviral Drugs ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

Infections caused by human immunodeficiency virus (HIV) are considered one of the main public health problems worldwide. Antiretroviral therapy (ART) is the current modality of treatment for HIV-1 infection. It comprises the combined use of several drugs and can decrease the viral load and increase the CD4+ T cell count in patients with HIV-1 infection, thereby proving to be an effective modality. This therapy significantly decreases the rate of morbidity and mortality owing to acquired immunodeficiency syndrome (AIDS) and prolongs and improves the quality of life of infected patients. However, nonadherence to ART may increase viral resistance to antiretroviral drugs and transmission of drug-resistant strains of HIV. Therefore, it is necessary to continue research for compounds with anti-HIV-1 activity, exhibiting a potential for the development of an alternative or complementary therapy to ART with low cost and fewer side effects. Natural products and their derivatives represent an excellent option owing to their therapeutic potential against HIV. Currently, the derivatives of natural products available as anti-HIV-1 agents include zidovudine, an arabinonucleoside derivative of the Caribbean marine sponge (Tectitethya crypta), which inhibits the reverse transcriptase of the virus. This was the first antiviral agent approved for treatment of HIV infection. Additionally, bevirimat (isolated from Syzygium claviflorum) and calanolide A (isolated from Calophyllum sp.) are inhibitors of viral maturation and reverse transcription process, respectively. In the present review, we aimed to describe the wide repertoire of natural compounds exhibiting anti-HIV-1 activity that can be considered for designing new therapeutic strategies to curb the HIV pandemic.

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 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.

scholarly journals Early Detection of Human Immunodeficiency Virus Type 1-Specific B-Lymphocyte-Derived Antibodies in a High-Risk Population

2009 ◽  
Vol 16 (7) ◽  
pp. 1060-1065 ◽  
Author(s):  
Odd Odinsen ◽  
David Parker ◽  
Frans Radebe ◽  
Mikey Guness ◽  
David A Lewis
Keyword(s):  
Human Immunodeficiency Virus ◽  
Viral Load ◽  
B Cell ◽  
Immunodeficiency Virus ◽  
Hiv Antibodies ◽  
P24 Antigen ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT Diagnosis of acute human immunodeficiency virus (HIV) infection, a key driver of the HIV epidemic, remains a public health challenge. The PlasmAcute technology offers an opportunity to detect early anti-HIV antibody responses. B lymphocytes (B cells) were isolated from the blood of seronegative miners in South Africa by using the PlasmAcute method. B-cell lysates and paired sera were tested for anti-HIV-1 antibodies by two different enzyme-linked immunosorbent assays; immunoreactivity was confirmed by Western blotting. All volunteers were tested for HIV type 1 (HIV-1) viral load, p24 antigen, and CD4 count. Sera from HIV-seronegative men who had positive viral loads and were positive for p24 antigen were retested for anti-HIV antibodies after immune complex dissociation. Anti-HIV antibodies were detected in lysates from 16/259 subjects without immunoreactivity in paired sera. Four subjects, one of whom had a positive viral load initially, subsequently seroconverted. Six subjects showed transient anti-HIV-1 antibodies in the lysates and tested negative for all markers at the follow-up. Five subjects without follow-up data initially had lysate-positive/serum-negative samples, and these cases were classified as inconclusive. One subject had lysate antibodies and a detectable viral load but was seronegative at follow-up. In conclusion, lysate-derived anti-HIV-1 B-cell antibodies can be detected prior to seroconversion and earlier than or contemporary with HIV-1 RNA detection.

An Approach towards the Synthesis of Potential Metal-Chelating TSAO-T Derivatives as Bidentate Inhibitors of Human Immunodeficiency virus Type 1 Reverse Transcriptase

1998 ◽  
Vol 9 (5) ◽  
pp. 412-421 ◽  
Author(s):  
C Chamorro ◽  
M-J Camarasa ◽  
M-J Pérez-Pérez ◽  
E de Clercq ◽  
J Balzarini ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Parent Compound ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

Novel derivatives of the potent human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) inhibitor TSAO-T have been designed, synthesized and tested for their in vitro antiretro-viral activity against HIV. These TSAO-T derivatives have been designed as potential bidentate inhibitors of HIV-1 RT, which combine in their structure the functionality of a non-nucleoside RT inhibitor (TSAO-T) and a bivalent ion-chelating moiety (a β-diketone moiety) linked through an appropriate spacer to the N-3 of thymine of TSAO-T . Some of the new compounds have an anti-HIV-1 activity comparable to that of the parent compound TSAO-T, but display a markedly increased antiviral selectivity. There was a clear relationship between antiviral activity and the length of the spacer group that links the TSAO molecule with the chelating moiety. A shorter spacer invariably resulted in increased antiviral potency. None of the TSAO-T derivatives were endowed with anti-HIV-2 activity.

scholarly journals Novel Inhibitory Effects of γ-Glutamylcysteine Ethyl Ester against Human Immunodeficiency Virus Type 1 Production and Propagation

1998 ◽  
Vol 42 (5) ◽  
pp. 1200-1206 ◽  
Author(s):  
Satoshi Kubota ◽  
Shubhra Shetty ◽  
Huizhong Zhang ◽  
Shigehisa Kitahara ◽  
Roger J. Pomerantz
Keyword(s):  
Human Immunodeficiency Virus ◽  
Ethyl Ester ◽  
Human Immunodeficiency Virus Type ◽  
Inhibitory Effects ◽  
Immunodeficiency Virus ◽  
Acute Hiv ◽  
High Doses ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT The anti-human immunodeficiency virus type I (anti-HIV-1) effects of γ-glutamylcysteine ethyl ester (γ-GCE; TEI-2306) were examined in vitro. In initial studies using a vigorously HIV-1-producing human T-lymphocytic cell line, γ-GCE displayed a novel biphasic repressive effect on chronic HIV-1 infection that was unlike that of other glutathione prodrugs or other reported antioxidants. In high doses, up to a concentration of 2.5 mM, at which neither glutathione (GSH) nor another GSH precursor has shown inhibitory effects, γ-GCE potently inhibited the production of HIV-1 by a selective cytopathic effect against infected cells, while the viability and growth of uninfected cells were unaffected at the same γ-GCE concentrations. At lower concentrations (200 to 400 μM), γ-GCE significantly repressed the virus production from chronically HIV-1-expressing cells without affecting their viability. The discrepancy of the thresholds of the toxic doses between infected and uninfected cells was found to be more than 10-fold. Relatively high doses of γ-GCE, utilized in acute HIV-1 infection of T-lymphocytic cells, entirely blocked the propagation of HIV-1 and rescued the cells from HIV-1-induced cell death. Furthermore, γ-GCE at such concentrations was found to directly inhibit the infectivity of HIV-1 within 4 h. Repressive effects of γ-GCE on acute HIV-1 infection in human primary human peripheral blood mononuclear cells were also demonstrated. Here, the anti-HIV-1 strategy utilizing γ-GCE is removal of both HIV-1-producing cells and free infectious HIV-1 in vitro, in place of specific immunoclearance in vivo, which might lead to an arrest or slowing of viral propagation in HIV-1-infected individuals.

Synthesis and Antiviral Activity of 1,3-Disubstituted Uracils against HIV-1 and HCMV

2003 ◽  
Vol 14 (5) ◽  
pp. 271-279 ◽  
Author(s):  
Tokumi Maruyama ◽  
Shigetada Kozai ◽  
Tetsuo Yamasaki ◽  
Myriam Witvrouw ◽  
Christophe Pannecouque ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Antiviral Activity ◽  
Human Cytomegalovirus ◽  
Therapeutic Agents ◽  
Reverse Transcriptase Inhibitors ◽  
Uracil Derivatives ◽  
Immunodeficiency Virus ◽  
Anti Hiv Agents ◽  
Anti Hiv ◽  
Hiv 1

The development of new non-nucleoside reverse transcriptase inhibitors (NNRTIs) is an efficient strategy for finding new therapeutic agents against human immunodeficiency virus (HIV). A large number of 6-substituted uracil derivatives have been prepared in order to explore new NNRTIs. However, there are few approaches to anti-HIV agents from 1,3-disubstituted uracil derivatives. Therefore, we tried to prepare several 1,3-disubstituted uracils, which were easily obtainable from uracil by preparation under alkali and Mitsunobu conditions, and examined their antiviral activity against HIV-1 and human cytomegalovirus (HCMV). We found that 1-benzyl-3-(3,5-dimethylbenzyl)uracil and 1-cyanomethyl-3-(3,5-dimethylbenzyl)-4-thiouracil showed powerful inhibition against HCMV and HIV-1, respectively.

TXU (Anti-CD7)-Pokeweed Antiviral Protein as a Potent Inhibitor of Human Immunodeficiency Virus

1998 ◽  
Vol 42 (2) ◽  
pp. 383-388 ◽  
Author(s):  
Fatih M. Uckun ◽  
Lisa M. Chelstrom ◽  
Lisa Tuel-Ahlgren ◽  
Ilker Dibirdik ◽  
James D. Irvin ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Scid Mouse ◽  
Pokeweed Antiviral Protein ◽  
Antiviral Protein ◽  
Cynomolgus Monkeys ◽  
Immunodeficiency Virus ◽  
Scid Mouse Model ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT We have evaluated the clinical potential of TXU (anti-CD7)-pokeweed antiviral protein (PAP) immunoconjugate (TXU-PAP) as a new biotherapeutic anti-human immunodeficiency virus (anti-HIV) agent by evaluating its anti-HIV type 1 (anti-HIV-1) activity in vitro, as well as in a surrogate human peripheral blood lymphocyte-severe combined immunodeficient (Hu-PBL-SCID) mouse model of human AIDS. The present report documents in a side-by-side comparison the superior in vitro anti-HIV-1 activity of TXU-PAP compared to the activities of zidovudine, 2′,3′-didehydro-2′,3′-dideoxythymidine, unconjugated PAP, and B53-PAP, an anti-CD4-PAP immunoconjugate. Notably, TXU-PAP elicited potent anti-HIV activity in the Hu-PBL-SCID mouse model of human AIDS without any side effects and at doses that were very well tolerated by cynomolgus monkeys. Furthermore, plasma samples from TXU-PAP-treated cynomolgus monkeys showed potent anti-HIV-1 activity in vitro.

scholarly journals Inhibition of Human Immunodeficiency Virus Type 1 Infectivity by Secretory Leukocyte Protease Inhibitor Occurs Prior to Viral Reverse Transcription

Blood ◽  
1997 ◽  
Vol 90 (3) ◽  
pp. 1141-1149 ◽  
Author(s):  
Tessie B. McNeely ◽  
Diane C. Shugars ◽  
Mary Rosendahl ◽  
Christina Tucker ◽  
Stephen P. Eisenberg ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Protease Inhibitor ◽  
Viral Infection ◽  
Reverse Transcription ◽  
Inhibitory Activity ◽  
Virus Binding ◽  
Viral Dna ◽  
Immunodeficiency Virus ◽  
Anti Hiv ◽  
Hiv 1

Abstract Infection of monocytes with human immunodeficiency virus type 1Ba-L (HIV-1Ba-L ) is significantly inhibited by treatment with the serine protease inhibitor, secretory leukocyte protease inhibitor (SLPI). SLPI does not appear to act on virus directly, but rather the inhibitory activity is most likely due to interaction with the host cell. The current study was initiated to investigate how SLPI interacts with monocytes to inhibit infection. SLPI was found to bind to monocytes with high affinity to a single class of receptor sites (∼7,000 receptors per monocyte, KD = 3.6 nmol/L). The putative SLPI receptor was identified as a surface protein with a molecular weight of 55 ± 5 kD. A well-characterized function of SLPI is inhibition of neutrophil elastase and cathepsin G. However, two SLPI mutants (or muteins) that contain single amino acid substitutions and exhibit greatly reduced protease inhibitory activity still bound to monocytes and retained anti–HIV-1 activity. SLPI consists of two domains, of which the C-terminal domain contains the protease inhibiting region. However, when tested independently, neither domain had potent anti–HIV-1 activity. SLPI binding neither prevented virus binding to monocytes nor attenuated the infectivity of any virus progeny that escaped inhibition by SLPI. A polymerase chain reaction (PCR)-based assay for newly generated viral DNA demonstrated that SLPI blocks at or before viral DNA synthesis. Therefore, it most likely inhibits a step of viral infection that occurs after virus binding but before reverse transcription. Taken together, the unique antiviral activity of SLPI, which may be independent of its previously characterized antiprotease activity, appears to reside in disruption of the viral infection process soon after virus binding.

scholarly journals Inhibition of Human Immunodeficiency Virus by a New Class of Pyridine Oxide Derivatives

2003 ◽  
Vol 47 (9) ◽  
pp. 2951-2957 ◽  
Author(s):  
Miguel Stevens ◽  
Christophe Pannecouque ◽  
Erik De Clercq ◽  
Jan Balzarini
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Cell Cultures ◽  
New Class ◽  
Nonnucleoside Reverse Transcriptase Inhibitors ◽  
Immunodeficiency Virus ◽  
Amino Acid Mutations ◽  
Anti Hiv ◽  
Hiv 1

ABSTRACT A new class of pyridine oxide derivatives as inhibitors of human immunodeficiency virus type 1 (HIV-1) and/or HIV-2 replication in cell culture has been identified. The compounds, which specifically inhibit HIV-1, behave as typical nonnucleoside reverse transcriptase inhibitors (NNRTIs). The most active congener of this group, JPL-133 (UC-B3096), has a 50% effective concentration of 0.05 μg/ml for HIV-1(IIIB) with a selectivity index of approximately 760 in CEM cell cultures. However, the cytostatic activity of most pyridine oxide derivatives highly depended on the nature of the cell line. All compounds, including those pyridine oxide derivatives that inhibit both HIV-1 and HIV-2 replication, select for NNRTI-characteristic mutations in the HIV-1 reverse transcriptase of HIV-infected cell cultures (i.e., Lys103Asn, Val108Ile, Glu138Lys, Tyr181Cys and Tyr188His). These amino acid mutations emerged mostly through transition of guanine to adenine or adenine to guanine in the corresponding codons of the reverse transcriptase (RT) gene. The HIV-1-specific pyridine oxide derivatives lost their antiviral activity against HIV-1 strains containing these mutations in the RT. However, most compounds retained pronounced antiviral potency against virus strains that contained other NNRTI-characteristic RT mutations, such as Leu100Ile and Val179Asp. Furthermore, the complete lack of inhibitory activity of the pyridine oxide derivatives against recombinant HIV-2 RT and partial retention of anti-HIV-1 activity against HIV-1 strains that contain a variety of HIV-1-characteristic mutations suggest that the pyridine oxide derivatives must have a second target of antiviral action independent from HIV-1 RT.

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