scholarly journals Potent, Broad-Spectrum Inhibition of Human Immunodeficiency Virus Type 1 by the CCR5 Monoclonal Antibody PRO 140

2001 ◽  
Vol 75 (2) ◽  
pp. 579-588 ◽  
Author(s):  
Alexandra Trkola ◽  
Thomas J. Ketas ◽  
Kirsten A. Nagashima ◽  
Lu Zhao ◽  
Tonie Cilliers ◽  
...  

ABSTRACT CCR5 serves as a requisite fusion coreceptor for clinically relevant strains of human immunodeficiency virus type 1 (HIV-1) and provides a promising target for antiviral therapy. However, no study to date has examined whether monoclonal antibodies, small molecules, or other nonchemokine agents possess broad-spectrum activity against the major genetic subtypes of HIV-1. PRO 140 (PA14) is an anti-CCR5 monoclonal antibody that potently inhibits HIV-1 entry at concentrations that do not affect CCR5's chemokine receptor activity. In this study, PRO 140 was tested against a panel of primary HIV-1 isolates selected for their genotypic and geographic diversity. In quantitative assays of viral infectivity, PRO 140 was compared with RANTES, a natural CCR5 ligand that can inhibit HIV-1 entry by receptor downregulation as well as receptor blockade. Despite their divergent mechanisms of action and binding epitopes on CCR5, low nanomolar concentrations of both PRO 140 and RANTES inhibited infection of primary peripheral blood mononuclear cells (PBMC) by all CCR5-using (R5) viruses tested. This is consistent with there being a highly restricted pattern of CCR5 usage by R5 viruses. In addition, a panel of 25 subtype C South African R5 viruses were broadly inhibited by PRO 140, RANTES, and TAK-779, although ∼30-fold-higher concentrations of the last compound were required. Interestingly, significant inhibition of a dualtropic subtype C virus was also observed. Whereas PRO 140 potently inhibited HIV-1 replication in both PBMC and primary macrophages, RANTES exhibited limited antiviral activity in macrophage cultures. Thus CCR5-targeting agents such as PRO 140 can demonstrate potent and genetic-subtype-independent anti-HIV-1 activity.

2005 ◽  
Vol 49 (10) ◽  
pp. 4110-4120 ◽  
Author(s):  
Dong-Seong Lee ◽  
Kyeong-Eun Jung ◽  
Cheol-Hee Yoon ◽  
Hong Lim ◽  
Yong-Soo Bae

ABSTRACT A series of modified oligonucleotides (ONs), characterized by a phosphorothioate (P═S) backbone and a six-membered azasugar (6-AZS) as a sugar substitute in a nucleotide, were newly synthesized and assessed for their ability to inhibit human immunodeficiency virus type 1 (HIV-1) via simple treatment of HIV-1-infected cultures, without any transfection process. While unmodified P═S ONs exhibited only minor anti-HIV-1 activity, the six-membered azasugar nucleotide (6-AZN)-containing P═S oligonucleotides (AZPSONs) exhibited remarkable antiviral activity against HIV-1/simian-human immunodeficiency virus (SHIV) replication and syncytium formation (50% effective concentration = 0.02 to 0.2 μM). The AZPSONs exhibited little cytotoxicity at concentrations of up to 100 μM. DBM 2198, one of the most effective AZPSONs, exhibited antiviral activity against a broad spectrum of HIV-1, including T-cell-tropic, monotropic, and even drug-resistant HIV-1 variants. The anti-HIV-1 activities of DBM 2198 were similarly maintained in HIV-1-infected cultures of peripheral blood mononuclear cells. When we treated severely infected cultures with DBM 2198, syncytia disappeared completely within 2 days. Taken together, our results indicate that DBM 2198 and other AZPSONs may prove useful in the further development of safe and effective AIDS-therapeutic drugs against a broad spectrum of HIV-1 variants.


2003 ◽  
Vol 77 (7) ◽  
pp. 4449-4456 ◽  
Author(s):  
Tonie Cilliers ◽  
Jabulani Nhlapo ◽  
Mia Coetzer ◽  
Dragana Orlovic ◽  
Thomas Ketas ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) subtype C viruses with different coreceptor usage profiles were isolated from 29 South African patients with advanced AIDS. All 24 R5 isolates were inhibited by the CCR5-specific agents, PRO 140 and RANTES, while the two X4 viruses and the three R5X4 viruses were sensitive to the CXCR4-specific inhibitor, AMD3100. The five X4 or R5X4 viruses were all able to replicate in peripheral blood mononuclear cells that did not express CCR5. When tested using coreceptor-transfected cell lines, one R5 virus was also able to use CXCR6, and another R5X4 virus could use CCR3, BOB/GPR15, and CXCR6. The R5X4 and X4 viruses contained more-diverse V3 loop sequences, with a higher overall positive charge, than the R5 viruses. Hence, some HIV-1 subtype C viruses are able to use CCR5, CXCR4, or both CXCR4 and CCR5 for entry, and they are sensitive to specific inhibitors of entry via these coreceptors. These observations are relevant to understanding the rapid spread of HIV-1 subtype C in the developing world and to the design of intervention and treatment strategies.


2009 ◽  
Vol 83 (11) ◽  
pp. 5592-5605 ◽  
Author(s):  
Awet Abraha ◽  
Immaculate L. Nankya ◽  
Richard Gibson ◽  
Korey Demers ◽  
Denis M. Tebit ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) subtype C is the dominant subtype globally, due largely to the incidence of subtype C infections in sub-Saharan Africa and east Asia. We compared the relative replicative fitness (ex vivo) of the major (M) group of HIV-1 subtypes A, B, C, D, and CRF01_AE and group O isolates. To estimate pathogenic fitness, pairwise competitions were performed between CCR5-tropic (R5) or CXCR4-tropic (X4) virus isolates in peripheral blood mononuclear cells (PBMC). A general fitness order was observed among 33 HIV-1 isolates; subtype B and D HIV-1 isolates were slightly more fit than the subtype A and dramatically more fit than the 12 subtype C isolates. All group M isolates were more fit (ex vivo) than the group O isolates. To estimate ex vivo transmission fitness, a subset of primary HIV-1 isolates were examined in primary human explants from penile, cervical, and rectal tissues. Only R5 isolates and no X4 HIV-1 isolates could replicate in these tissues, whereas the spread to PM1 cells was dependent on active replication and passive virus transfer. In tissue competition experiments, subtype C isolates could compete with and, in some cases, even win over subtype A and D isolates. However, when the migratory cells from infected tissues were mixed with a susceptible cell line, the subtype C isolates were outcompeted by other subtypes, as observed in experiments with PBMC. These findings suggest that subtype C HIV-1 isolates might have equal transmission fitness but reduced pathogenic fitness relative to other group M HIV-1 isolates.


2007 ◽  
Vol 81 (12) ◽  
pp. 6187-6196 ◽  
Author(s):  
E. S. Gray ◽  
P. L. Moore ◽  
I. A. Choge ◽  
J. M. Decker ◽  
F. Bibollet-Ruche ◽  
...  

ABSTRACT The study of the evolution and specificities of neutralizing antibodies during the course of human immunodeficiency virus type 1 (HIV-1) infection may be important in the discovery of possible targets for vaccine design. In this study, we assessed the autologous and heterologous neutralization responses of 14 HIV-1 subtype C-infected individuals, using envelope clones obtained within the first 2 months postinfection. Our data show that potent but relatively strain-specific neutralizing antibodies develop within 3 to 12 months of HIV-1 infection. The magnitude of this response was associated with shorter V1-to-V5 envelope lengths and fewer glycosylation sites, particularly in the V1-V2 region. Anti-MPER antibodies were detected in 4 of 14 individuals within a year of infection, while antibodies to CD4-induced (CD4i) epitopes developed to high titers in 12 participants, in most cases before the development of autologous neutralizing antibodies. However, neither anti-MPER nor anti-CD4i antibody specificity conferred neutralization breadth. These data provide insights into the kinetics, potency, breadth, and epitope specificity of neutralizing antibody responses in acute HIV-1 subtype C infection.


2001 ◽  
Vol 75 (16) ◽  
pp. 7266-7279 ◽  
Author(s):  
Dai Wang ◽  
Cynthia de la Fuente ◽  
Longwen Deng ◽  
Lai Wang ◽  
Irene Zilberman ◽  
...  

ABSTRACT Cyclin-dependent kinases (cdk's) have recently been suggested to regulate human immunodeficiency virus type 1 (HIV-1) transcription. Previously, we have shown that expression of one cdk inhibitor, p21/Waf1, is abrogated in HIV-1 latently infected cells. Based on this result, we investigated the transcription of HIV-1 in the presence of chemical drugs that specifically inhibited cdk activity and functionally mimicked p21/Waf1 activity. HIV-1 production in virally integrated lymphocytic and monocytic cell lines, such as ACH2, 8E5, and U1, as well as activated peripheral blood mononuclear cells infected with syncytium-inducing (SI) or non-syncytium-inducing (NSI) HIV-1 strains, were all inhibited by Roscovitine, a purine derivative that reversibly competes for the ATP binding site present in cdk's. The decrease in viral progeny in the HIV-1-infected cells was correlated with a decrease in the transcription of HIV-1 RNAs in cells treated with Roscovitine and not with the non-cdk general cell cycle inhibitors, such as hydroxyurea (G1/S blocker) or nocodazole (M-phase blocker). Cyclin A- and E-associated histone H1 kinases, as well as cdk 7 and 9 activities, were all inhibited in the presence of Roscovitine. The 50% inhibitory concentration of Roscovitine on cdk's 9 and 7 was determined to be ∼0.6 μM. Roscovitine could selectively sensitize HIV-1-infected cells to apoptosis at concentrations that did not impede the growth and proliferation of uninfected cells. Apoptosis induced by Roscovitine was found in both latent and activated infected cells, as evident by Annexin V staining and the cleavage of the PARP protein by caspase-3. More importantly, contrary to many apoptosis-inducing agents, where the apoptosis of HIV-1-infected cells accompanies production and release of infectious HIV-1 viral particles, Roscovitine treatment selectively killed HIV-1-infected cells without virion release. Collectively, our data suggest that cdk's are required for efficient HIV-1 transcription and, therefore, we propose specific cdk inhibitors as potential antiviral agents in the treatment of AIDS.


2006 ◽  
Vol 80 (12) ◽  
pp. 6056-6060 ◽  
Author(s):  
Aleksandr Lazaryan ◽  
Elena Lobashevsky ◽  
Joseph Mulenga ◽  
Etienne Karita ◽  
Susan Allen ◽  
...  

ABSTRACT Human leukocyte antigen (HLA) class I alleles can be grouped into supertypes according to their shared peptide binding properties. We examined alleles of the HLA-B58 supertype (B58s) in treatment-naïve human immunodeficiency virus type 1 (HIV-1)-seropositive Africans (423 Zambians and 202 Rwandans). HLA-B and HLA-C alleles were resolved to four digits by a combination of molecular methods, and their respective associations with outcomes of HIV-1 infection were analyzed by statistical procedures appropriate for continuous or categorical data. The effects of the individual alleles on natural HIV-1 infection were heterogeneous. In HIV-1 subtype C-infected Zambians, the mean viral load (VL) was lower among B*5703 (P = 0.01) or B*5703-Cw*18 (P < 0.001) haplotype carriers and higher among B*5802 (P = 0.02) or B*5802-Cw*0602 (P = 0.03) carriers. The B*5801-Cw*03 haplotype showed an association with low VL (P = 0.05), whereas B*5801 as a whole did not. Rwandans with HIV-1 subtype A infection showed associations of B*5703 and B*5802 with slow (P = 0.06) and rapid (P = 0.003) disease progression, respectively. In neither population were B*1516-B*1517 alleles associated with more favorable responses. Overall, B58s alleles, individually or as part of an HLA-B-HLA-C haplotype, appeared to have a distinctive impact on HIV-1 infection among native Africans. As presently defined, B58s alleles cannot be considered uniformly protective against HIV/AIDS in every population.


2004 ◽  
Vol 78 (5) ◽  
pp. 2586-2590 ◽  
Author(s):  
Udaykumar Ranga ◽  
Raj Shankarappa ◽  
Nagadenahalli B. Siddappa ◽  
Lakshmi Ramakrishna ◽  
Ramalingam Nagendran ◽  
...  

ABSTRACT Human immunodeficiency virus type 1 (HIV-1)-associated dementia (HAD) is correlated with increased monocyte migration to the brain, and the incidence of HAD among otherwise asymptomatic subjects appears to be lower in India than in the United States and Europe (1 to 2% versus 15 to 30%). Because of the genetic differences between HIV-1 strains circulating in these regions, we sought to identify viral determinants associated with this difference. We targeted Tat protein for these studies in view of its association with monocyte chemotactic function. Analyses of Tat sequences representing nine subtypes revealed that at least six amino acid residues are differentially conserved in subtype C Tat (C-Tat). Of these, cysteine (at position 31) was highly (>99%) conserved in non-subtype C viruses and more than 90% of subtype C viruses encoded a serine. We hypothesized a compromised chemotactic function of C-Tat due to the disruption of CC motif and tested it with the wild type C-Tat (CS) and its two isogenic variants (CC and SC) derived by site-directed mutagenesis. We found that the CS natural variant was defective for monocyte chemotactic activity without a loss in the transactivation property. While the CC mutant is functionally competent for both the functions, in contrast, the SC mutant was defective in both. Therefore, the loss of the C-Tat chemotactic property may underlie the reduced incidence of HAD; although not presenting conclusive evidence, this study provides the first evidence for a potential epidemiologic phenomenon associated with biological differences in the subtype C viruses.


2005 ◽  
Vol 79 (10) ◽  
pp. 6089-6101 ◽  
Author(s):  
Bruce K. Brown ◽  
Janice M. Darden ◽  
Sodsai Tovanabutra ◽  
Tamara Oblander ◽  
Julie Frost ◽  
...  

ABSTRACT A critical priority for human immunodeficiency virus type 1 (HIV-1) vaccine development is standardization of reagents and assays for evaluation of immune responses elicited by candidate vaccines. To provide a panel of viral reagents from multiple vaccine trial sites, 60 international HIV-1 isolates were expanded in peripheral blood mononuclear cells and characterized both genetically and biologically. Ten isolates each from clades A, B, C, and D and 10 isolates each from CRF01_AE and CRF02_AG were prepared from individuals whose HIV-1 infection was evaluated by complete genome sequencing. The main criterion for selection was that the candidate isolate was pure clade or pure circulating recombinant. After expansion in culture, the complete envelope (gp160) of each isolate was verified by sequencing. The 50% tissue culture infectious dose and p24 antigen concentration for each viral stock were determined; no correlation between these two biologic parameters was found. Syncytium formation in MT-2 cells and CCR5 or CXCR4 coreceptor usage were determined for all isolates. Isolates were also screened for neutralization by soluble CD4, a cocktail of monoclonal antibodies, and a pool of HIV-1-positive patient sera. The panel consists of 49 nonsyncytium-inducing isolates that use CCR5 as a major coreceptor and 11 syncytium-inducing isolates that use only CXCR4 or both coreceptors. Neutralization profiles suggest that the panel contains both neutralization-sensitive and -resistant isolates. This collection of HIV-1 isolates represents the six major globally prevalent strains, is exceptionally large and well characterized, and provides an important resource for standardization of immunogenicity assessment in HIV-1 vaccine trials.


2004 ◽  
Vol 48 (5) ◽  
pp. 1652-1663 ◽  
Author(s):  
Olaf Kutsch ◽  
David N. Levy ◽  
Paula J. Bates ◽  
Julie Decker ◽  
Barry R. Kosloff ◽  
...  

ABSTRACT The increasing numbers of human immunodeficiency virus type 1 (HIV-1) strains that exhibit resistance to antiretroviral agents used at present require the development of new effective antiretroviral compounds. Tat transactivation was recognized early on as an attractive target for drug interference. To screen for and analyze the effects of compounds that interfere with Tat transactivation, we developed several cell-based reporter systems in which enhanced green fluorescence protein is a direct and quantitative marker of HIV-1 expression or Tat-dependent long terminal repeat activity. Using these reporter cell lines, we found that the bis-anthracycline WP631, a recently developed DNA intercalator, efficiently inhibits HIV-1 expression at subcytotoxic concentrations. WP631 also abrogated acute HIV-1 replication in peripheral blood mononuclear cells infected with various primary virus isolates. We demonstrate that WP631-mediated HIV-1 inhibition is caused by the inhibition of Tat transactivation. The data presented suggest that WP631 could serve as a lead compound for a new type of HIV-1 inhibitor.


2004 ◽  
Vol 85 (2) ◽  
pp. 409-413 ◽  
Author(s):  
Ann Jaffray ◽  
Enid Shephard ◽  
Joanne van Harmelen ◽  
Carolyn Williamson ◽  
Anna-Lise Williamson ◽  
...  

Human immunodeficiency virus type 1 (HIV-1) subtype C is the predominant HIV in southern Africa, and is the target of a number of recent vaccine candidates. It has been proposed that a heterologous prime/boost vaccination strategy may result in stronger, broader and more prolonged immune responses. Since HIV-1 Gag Pr55 polyprotein can assemble into virus-like particles (VLPs) which have been shown to induce a strong cellular immune response in animals, we showed that a typical southern African subtype C Pr55 protein expressed in insect cells via recombinant baculovirus could form VLPs. We then used the baculovirus-produced VLPs as a boost to a subtype C HIV-1 gag DNA prime vaccination in mice. This study shows that a low dose of HIV-1 subtype C Gag VLPs can significantly boost the immune response to a single subtype C gag DNA inoculation in mice. These results suggest a possible vaccination regimen for humans.


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