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Umotoy JC, de Taeye SW. Antibody Conjugates for Targeted Therapy Against HIV-1 as an Emerging Tool for HIV-1 Cure. Front Immunol 2021; 12:708806. [PMID: 34276704 PMCID: PMC8282362 DOI: 10.3389/fimmu.2021.708806] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 06/18/2021] [Indexed: 01/22/2023] Open
Abstract
Although advances in antiretroviral therapy (ART) have significantly improved the life expectancy of people living with HIV-1 (PLWH) by suppressing HIV-1 replication, a cure for HIV/AIDS remains elusive. Recent findings of the emergence of drug resistance against various ART have resulted in an increased number of treatment failures, thus the development of novel strategies for HIV-1 cure is of immediate need. Antibody-based therapy is a well-established tool in the treatment of various diseases and the engineering of new antibody derivatives is expanding the realms of its application. An antibody-based carrier of anti-HIV-1 molecules, or antibody conjugates (ACs), could address the limitations of current HIV-1 ART by decreasing possible off-target effects, reduce toxicity, increasing the therapeutic index, and lowering production costs. Broadly neutralizing antibodies (bNAbs) with exceptional breadth and potency against HIV-1 are currently being explored to prevent or treat HIV-1 infection in the clinic. Moreover, bNAbs can be engineered to deliver cytotoxic or immune regulating molecules as ACs, further increasing its therapeutic potential for HIV-1 cure. ACs are currently an important component of anticancer treatment with several FDA-approved constructs, however, to date, no ACs are approved to treat viral infections. This review aims to outline the development of AC for HIV-1 cure, examine the variety of carriers and payloads used, and discuss the potential of ACs in the current HIV-1 cure landscape.
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Affiliation(s)
- Jeffrey C Umotoy
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Center (UMC), Amsterdam Infection and Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
| | - Steven W de Taeye
- Laboratory of Experimental Virology, Department of Medical Microbiology, Amsterdam University Medical Center (UMC), Amsterdam Infection and Immunity Institute, University of Amsterdam, Amsterdam, Netherlands
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Citores L, Iglesias R, Ferreras JM. Antiviral Activity of Ribosome-Inactivating Proteins. Toxins (Basel) 2021; 13:80. [PMID: 33499086 PMCID: PMC7912582 DOI: 10.3390/toxins13020080] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/14/2021] [Accepted: 01/20/2021] [Indexed: 12/13/2022] Open
Abstract
Ribosome-inactivating proteins (RIPs) are rRNA N-glycosylases from plants (EC 3.2.2.22) that inactivate ribosomes thus inhibiting protein synthesis. The antiviral properties of RIPs have been investigated for more than four decades. However, interest in these proteins is rising due to the emergence of infectious diseases caused by new viruses and the difficulty in treating viral infections. On the other hand, there is a growing need to control crop diseases without resorting to the use of phytosanitary products which are very harmful to the environment and in this respect, RIPs have been shown as a promising tool that can be used to obtain transgenic plants resistant to viruses. The way in which RIPs exert their antiviral effect continues to be the subject of intense research and several mechanisms of action have been proposed. The purpose of this review is to examine the research studies that deal with this matter, placing special emphasis on the most recent findings.
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Affiliation(s)
| | | | - José M. Ferreras
- Department of Biochemistry and Molecular Biology and Physiology, Faculty of Sciences, University of Valladolid, E-47011 Valladolid, Spain; (L.C.); (R.I.)
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3
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Ward AR, Mota TM, Jones RB. Immunological approaches to HIV cure. Semin Immunol 2020; 51:101412. [PMID: 32981836 DOI: 10.1016/j.smim.2020.101412] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 09/10/2020] [Indexed: 02/07/2023]
Abstract
Combination antiretroviral therapy (ART) to treat human immunodeficiency virus (HIV) infection has proven remarkably successful - for those who can access and afford it - yet HIV infection persists indefinitely in a reservoir of cells, despite effective ART and despite host antiviral immune responses. An HIV cure is therefore the next aspirational goal and challenge, though approaches differ in their objectives - with 'functional cures' aiming for durable viral control in the absence of ART, and 'sterilizing cures' aiming for the more difficult to realize objective of complete viral eradication. Mechanisms of HIV persistence, including viral latency, anatomical sequestration, suboptimal immune functioning, reservoir replenishment, target cell-intrinsic immune resistance, and, potentially, target cell distraction of immune effectors, likely need to be overcome in order to achieve a cure. A small fraction of people living with HIV (PLWH) naturally control infection via immune-mediated mechanisms, however, providing both sound rationale and optimism that an immunological approach to cure is possible. Herein we review up to date knowledge and emerging evidence on: the mechanisms contributing to HIV persistence, as well as potential strategies to overcome these barriers; promising immunological approaches to achieve viral control and elimination of reservoir-harboring cells, including harnessing adaptive immune responses to HIV and engineered therapies, as well as enhancers of their functions and of complementary innate immune functioning; and combination strategies that are most likely to succeed. Ultimately, a cure must be safe, effective, durable, and, eventually, scalable in order to be widely acceptable and available.
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Affiliation(s)
- Adam R Ward
- Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA; Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC, USA; PhD Program in Epidemiology, The George Washington University, Washington, DC, USA
| | - Talia M Mota
- Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA
| | - R Brad Jones
- Division of Infectious Diseases, Weill Cornell Medicine, New York, NY, USA; Department of Microbiology, Immunology, and Tropical Medicine, The George Washington University, Washington, DC, USA.
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Spiess K, Jakobsen MH, Kledal TN, Rosenkilde MM. The future of antiviral immunotoxins. J Leukoc Biol 2016; 99:911-25. [PMID: 26729815 DOI: 10.1189/jlb.2mr1015-468r] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Accepted: 12/03/2015] [Indexed: 01/06/2023] Open
Abstract
There is a constant need for new therapeutic interventions in a wide range of infectious diseases. Over the past few years, the immunotoxins have entered the stage as promising antiviral treatments. Immunotoxins have been extensively explored in cancer treatment and have achieved FDA approval in several cases. Indeed, the design of new anticancer immunotoxins is a rapidly developing field. However, at present, several immunotoxins have been developed targeting a variety of different viruses with high specificity and efficacy. Rather than blocking a viral or cellular pathway needed for virus replication and dissemination, immunotoxins exert their effect by killing and eradicating the pool of infected cells. By targeting a virus-encoded target molecule, it is possible to obtain superior selectivity and drastically limit the side effects, which is an immunotoxin-related challenge that has hindered the success of immunotoxins in cancer treatment. Therefore, it seems beneficial to use immunotoxins for the treatment of virus infections. One recent example showed that targeting of virus-encoded 7 transmembrane (7TM) receptors by immunotoxins could be a future strategy for designing ultraspecific antiviral treatment, ensuring efficient internalization and hence efficient eradication of the pool of infected cells, both in vitro and in vivo. In this review, we provide an overview of the mechanisms of action of immunotoxins and highlight the advantages of immunotoxins as future anti-viral therapies.
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Affiliation(s)
- Katja Spiess
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Science, University of Copenhagen, Denmark; and
| | - Mette Høy Jakobsen
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Science, University of Copenhagen, Denmark; and
| | - Thomas N Kledal
- Section for Virology, Veterinary Institute, The Danish Technical University, Denmark
| | - Mette M Rosenkilde
- Laboratory for Molecular Pharmacology, Department of Neuroscience and Pharmacology, Faculty of Health and Medical Science, University of Copenhagen, Denmark; and
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Denton PW, Long JM, Wietgrefe SW, Sykes C, Spagnuolo RA, Snyder OD, Perkey K, Archin NM, Choudhary SK, Yang K, Hudgens MG, Pastan I, Haase AT, Kashuba AD, Berger EA, Margolis DM, Garcia JV. Targeted cytotoxic therapy kills persisting HIV infected cells during ART. PLoS Pathog 2014; 10:e1003872. [PMID: 24415939 PMCID: PMC3887103 DOI: 10.1371/journal.ppat.1003872] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/22/2013] [Indexed: 11/18/2022] Open
Abstract
Antiretroviral therapy (ART) can reduce HIV levels in plasma to undetectable levels, but rather little is known about the effects of ART outside of the peripheral blood regarding persistent virus production in tissue reservoirs. Understanding the dynamics of ART-induced reductions in viral RNA (vRNA) levels throughout the body is important for the development of strategies to eradicate infectious HIV from patients. Essential to a successful eradication therapy is a component capable of killing persisting HIV infected cells during ART. Therefore, we determined the in vivo efficacy of a targeted cytotoxic therapy to kill infected cells that persist despite long-term ART. For this purpose, we first characterized the impact of ART on HIV RNA levels in multiple organs of bone marrow-liver-thymus (BLT) humanized mice and found that antiretroviral drug penetration and activity was sufficient to reduce, but not eliminate, HIV production in each tissue tested. For targeted cytotoxic killing of these persistent vRNA(+) cells, we treated BLT mice undergoing ART with an HIV-specific immunotoxin. We found that compared to ART alone, this agent profoundly depleted productively infected cells systemically. These results offer proof-of-concept that targeted cytotoxic therapies can be effective components of HIV eradication strategies.
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Affiliation(s)
- Paul W. Denton
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Julie M. Long
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Stephen W. Wietgrefe
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Craig Sykes
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Rae Ann Spagnuolo
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Olivia D. Snyder
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Katherine Perkey
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Nancie M. Archin
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Shailesh K. Choudhary
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Kuo Yang
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Michael G. Hudgens
- Department of Biostatistics, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Ira Pastan
- Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Ashley T. Haase
- Department of Microbiology, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Angela D. Kashuba
- Division of Pharmacotherapy and Experimental Therapeutics, UNC Eshelman School of Pharmacy, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - Edward A. Berger
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - David M. Margolis
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
| | - J. Victor Garcia
- Division of Infectious Diseases, Department of Medicine, UNC Center for AIDS Research, University of North Carolina School of Medicine, Chapel Hill, North Carolina, United States of America
- * E-mail:
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7
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Chu L, Wiley HS, Lauffenburger DA. Endocytic Relay as a Potential Means for Enhancing Ligand Transport through Cellular Tissue Matrices: Analysis and Possible Implications for Drug Delivery. ACTA ACUST UNITED AC 2011; 2:17-38. [PMID: 19877949 DOI: 10.1089/ten.1996.2.17] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The transport of peptide ligands, such as cytokines, through tissue is complicated by resistances due to cell multilayers and holdup in extracellular matrix. To determine whether it is possible for receptor-mediated endocytic trafficking to enhance ligand transport, we have developed a mathematical model of ligand flux through tissue containing cells possessing complementary receptors. Tissue is considered as two phases: the cell phase and the matrix phase; thus tissue is modeled as analogous to a packed bed reactor. This model allows calculation of steady-state flux of intact and degraded peptide through a one-dimensional cell/tissue matrix. Both environmental and molecular parameters were considered in this study. Results predict that three quantities should have a major influence on growth factor flux: the ratio of matrix diffusivity to intracellular "diffusivity" (D(m)/D(i)), the extracellular matrix proteolysis rate constant (k (prot)), and the fraction of internalized growth factor degraded (f(1)). For basal levels of intracellular degradation (0 < f(1) >/= 0.05) but no extracellular proteolysis, significant enhancement is possible only for D(m)/D(i) >/=1. f(1) increases, enhancement is only possible up to f(1)= 0.07 even for D(m)/D(i) < 1. For significant levels of extracellular proteolysis (k (prot) > 0), the requirements for D(m)/D(i) and f(1) to permit transport enhancement encompass a broader range with the exact values dependent on k (prot). These insights may be helpful for delivery of ligands generated from controlled-release devices or genetically modified autocrine cells, and may also provide better understanding of cytokine transport in embryonic development.
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Affiliation(s)
- L Chu
- Department of Chemical Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
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8
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Cai Y, Berger EA. An immunotoxin targeting the gH glycoprotein of KSHV for selective killing of cells in the lytic phase of infection. Antiviral Res 2011; 90:143-50. [PMID: 21440007 PMCID: PMC3102131 DOI: 10.1016/j.antiviral.2011.03.175] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 03/06/2011] [Accepted: 03/13/2011] [Indexed: 12/24/2022]
Abstract
Amongst the pathologies associated with infection by Kaposi's sarcoma-associated herpesvirus (KSHV), multicentric Castleman's disease is distinctive for involvement of the lytic phase of the virus replication cycle. This B cell lymphoproliferative disorder has shown clinical responsiveness not only to generalized immunotherapy and cytotoxic chemotherapy, but also to inhibitors of herpesvirus DNA replication, consistent with the involvement of lytic phase of replication. These findings suggest that selective killing of virus-producing cells might represent a novel therapeutic strategy. We designed an immunotoxin, YC15-PE38, containing a single chain variable region fragment of a monoclonal antibody against KSHV glycoprotein H (gH) linked to the effector domains of Pseudomonas aeruginosa exotoxin A. Purified YC15-PE38 displayed highly selective and potent killing of a gH-expressing transfectant cell line (subnanomolar IC(50)). The immunotoxin also strongly inhibited production of infectious KSHV virions from an induced chronically infected cell line, by virtue of selective killing of the virus-producing cells. Combination treatment studies indicated complementary activities between YC15-PE38 and the herpesviral DNA replication inhibitor ganciclovir. These results provide support for the development of anti-KSHV strategies based on targeted killing of infected cells expressing lytic phase genes.
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Affiliation(s)
- Yingyun Cai
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Edward A. Berger
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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10
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Annotated References: Anti-infectives. Expert Opin Investig Drugs 2008. [DOI: 10.1517/13543784.3.8.883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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11
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Kennedy PE, Bera TK, Wang QC, Gallo M, Wagner W, Lewis MG, Berger EA, Pastan I. Anti-HIV-1 immunotoxin 3B3(Fv)-PE38: enhanced potency against clinical isolates in human PBMCs and macrophages, and negligible hepatotoxicity in macaques. J Leukoc Biol 2006; 80:1175-82. [PMID: 16923920 DOI: 10.1189/jlb.0306139] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Highly active antiretroviral therapy (HAART) against human immunodeficiency virus type 1 (HIV-1) infection dramatically suppresses viral load, leading to marked reductions in HIV-1 associated morbidity and mortality. However, infected cell reservoirs and low-level replication persist in the face of suppressive HAART, leading invariably to viral rebound upon cessation of treatment. Toxins engineered to target the Env glycoprotein on the surface of productively infected cells represent a complementary strategy to deplete these reservoirs. We described previously highly selective killing of Env-expressing cell lines by CD4(178)-PE40 and 3B3(Fv)-PE38, recombinant derivatives of Pseudomonas aeruginosa exotoxin A containing distinct targeting moieties against gp120. In the present report, we compare the in vitro potency and breadth of these chimeric toxins against multiple clinical HIV-1 isolates, replicating in biologically relevant primary human target cell types. In PBMCs, 3B3(Fv)-PE38 blocked spreading infection by all isolates examined, with greater potency than CD4(178)-PE40. 3B3(Fv)-PE38 also potently inhibited spreading HIV-1 infection in primary macrophages. Control experiments demonstrated that in both target cell types, most of the 3B3(Fv)-PE38 activity was due to selective killing of infected cells, and not merely to neutralization by the antibody moiety of the chimeric toxin. High-dose treatment of rhesus macaques with 3B3(Fv)-PE38 did not induce liver toxicity, whereas equivalent dosage of CD4(178)-PE40 induced mild hepatotoxicity. These findings highlight the potential use of 3B3(Fv)-PE38 for depleting HIV-infected cell reservoirs persisting in the face of HAART.
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Affiliation(s)
- Paul E Kennedy
- Laboratory of Viral Diseases, NIAID, National Institutes of Health Building 4, Room 237 Bethesda, MD 20892, USA
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Casadevall A, Pirofski LA. The potential of antibody-mediated immunity in the defence against biological weapons. Expert Opin Biol Ther 2005; 5:1359-72. [PMID: 16197341 DOI: 10.1517/14712598.5.10.1359] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Antibody-mediated immunity (AMI) has been used for the treatment and prevention of infectious diseases for > 100 years, and has a remarkable record of safety, efficacy and versatility. AMI can be used for defence against a wide variety of biological weapons, and passive antibody (Ab) therapy has the potential to provide immediate immunity to susceptible individuals. Recent advances in the Ab field make it possible to generate Abs with enhanced antimicrobial functions. There are significant gaps in our understanding of Ab function, such that the development of Ab-based strategies remains a largely empirical exercise. Nevertheless, the advantages inherent in the therapeutic and prophylactic use of AMI provide a powerful rationale for continued development that will undoubtedly yield many new vaccines and therapeutic Abs.
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Affiliation(s)
- Arturo Casadevall
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Castagna A, Biswas P, Beretta A, Lazzarin A. The appealing story of HIV entry inhibitors : from discovery of biological mechanisms to drug development. Drugs 2005; 65:879-904. [PMID: 15892586 DOI: 10.2165/00003495-200565070-00001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Current therapeutic intervention in HIV infection relies upon 20 different drugs. Despite the impressive efficacy shown by these drugs, we are confronted with an unexpected frequency of adverse effects, such as mitochondrial toxicity and lipodystrophy, and resistance, not only to individual drugs but to entire drug classes.Thus, there is now a great need for new antiretroviral drugs with reduced toxicity, increased activity against drug-resistant viruses and a greater capacity to reach tissue sanctuaries of the virus. Two different HIV molecules have been selected as targets of drug inhibition so far: reverse transcriptase and protease. Drugs that target the interactions between the HIV envelope and the cellular receptor complex are a 'new entry' into the scenario of HIV therapy and have recently raised great interest because of their activity against multidrug-resistant viruses. There are several compounds that are at different developmental stages in the pipeline to counter HIV entry, among them: (i) the attachment inhibitor dextrin-2-sulfate; (ii) the inhibitors of the glycoprotein (gp) 120/CD4 interaction PRO 542, TNX 355 and BMS 488043; (iii) the co-receptor inhibitors subdivided in those targeting CCR5 (SCH 417690 [SCH D], UK 427857 GW 873140, PRO 140, TAK 220, AMD 887) and those targeting CXCR4 (AMD 070, KRH 2731); and (iv) the fusion inhibitors enfuvirtide (T-20) and tifuvirtide (T-1249). The story of the first of these drugs, enfuvirtide, which has successfully completed phase III clinical trials, has been approved by the US FDA and by the European Medicines Agency, and is now commercially available worldwide, is an example of how the knowledge of basic molecular mechanisms can rapidly translate into the development of clinically effective molecules.
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Affiliation(s)
- Antonella Castagna
- Clinic of Infectious Diseases, San Raffaele Scientific Institute, Milan, Italy
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Meyuhas R, Noy H, Montefiori DC, Denisova G, Gershoni JM, Gross G. HIV-1 neutralization by chimeric CD4-CG10 polypeptides fused to human IgG1. Mol Immunol 2005; 42:1099-109. [PMID: 15829299 DOI: 10.1016/j.molimm.2004.11.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Indexed: 11/28/2022]
Abstract
The envelope glycoprotein of HIV-1 is the principal target for entry inhibitors. The use of soluble CD4 has been found to be impractical as most clinical isolates are resistant to neutralization at feasible concentrations. CG10 is one of a small group of monoclonal antibodies specific to CD4-induced epitopes, which are structurally associated with the chemokine receptor-binding site and are capable of blocking the interaction of gp120 with its obligatory co-receptor. We have reasoned that fusing the single chain Fv of CG10 with CD4 can lead to increased HIV-1 neutralization activity and that this effect could be further enhanced by engrafting this chimeric construct onto an IgG Fc. Here we report the cloning of the genes encoding the variable regions of CG10 heavy and light chains and demonstrate that when attached to human IgG1 Fc, the single chain Fv of CG10 retains the binding properties of the original mouse antibody. Fusing CG10 single chain Fv with the gp120-binding portion of CD4 on a human IgG1 Fc backbone results in stronger binding of gp120 of different tropisms and in enhanced neutralization of laboratory-adapted strains and most, but not all, clade B and clade C isolates tested. Our findings underscore the potential use of CD4-based fusion proteins in the design of HIV immuno-therapeutics.
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Affiliation(s)
- Ronit Meyuhas
- Laboratory of Immunology, MIGAL - Galilee Technology Center, P.O. Box 831, Kiryat Shmona 11016, Israel
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15
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Pincus SH, Fang H, Wilkinson RA, Marcotte TK, Robinson JE, Olson WC. In vivo efficacy of anti-glycoprotein 41, but not anti-glycoprotein 120, immunotoxins in a mouse model of HIV infection. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2003; 170:2236-41. [PMID: 12574398 DOI: 10.4049/jimmunol.170.4.2236] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunotoxins (ITs) targeting the HIV envelope protein are among the most efficacious antiviral therapies when tested in vitro. Yet a first-generation IT targeted to gp120, CD4-PE40 (chimeric immunotoxin using CD4 and the translocation and enzymatic domains of Pseudomonas exotoxin A), showed limited promise in initial clinical testing, highlighting the need for improved ITs. We have used a new mouse model of HIV infection to test the comparative efficacy of anti-HIV ITs targeted to gp120 or to gp41. Irradiated SCID/nonobese diabetic mice are injected with a tumor of human CD4(+) cells susceptible to infection and at a separate site persistently HIV-infected cells. The spread of infection from infected to susceptible tumor is monitored by plasma p24 and the presence of HIV-infected cells in the spleen. Anti-gp41 ITs in combination with tetrameric CD4-human Ig fusion protein have pronounced anti-HIV effects. Little if any anti-HIV efficacy was found with either CD4-PE40 or an Ab-targeted anti-gp120 IT. These data support continued exploration of the utility of ITs for HIV infection, particularly the use of anti-gp41 ITs in combination with soluble CD4 derivatives.
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MESH Headings
- Animals
- Antibodies, Monoclonal/administration & dosage
- Antibodies, Monoclonal/pharmacokinetics
- Antibodies, Monoclonal/therapeutic use
- Antibodies, Viral/administration & dosage
- Antibodies, Viral/therapeutic use
- CD4 Immunoadhesins/administration & dosage
- CD4 Immunoadhesins/therapeutic use
- Disease Models, Animal
- Drug Therapy, Combination
- HIV Envelope Protein gp120/immunology
- HIV Envelope Protein gp41/immunology
- HIV Infections/immunology
- HIV Infections/prevention & control
- HIV Infections/virology
- HIV-1/immunology
- HeLa Cells
- Humans
- Immunotoxins/administration & dosage
- Immunotoxins/pharmacokinetics
- Immunotoxins/therapeutic use
- Injections, Intraperitoneal
- Mice
- Mice, Inbred NOD
- Mice, SCID
- Ricin/administration & dosage
- Ricin/pharmacokinetics
- Ricin/therapeutic use
- Tumor Cells, Cultured
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Affiliation(s)
- Seth H Pincus
- Department of Microbiology and Animal Resources Center, Montana State University, Bozeman, MT 59717, USA.
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Wesche J, Olsnes S. Ability of the Tat basic domain and VP22 to mediate cell binding, but not membrane translocation of the diphtheria toxin A-fragment. Biochemistry 2001; 40:4349-58. [PMID: 11284691 DOI: 10.1021/bi002443l] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A number of proteins are able to enter cells from the extracellular environment, including protein toxins, growth factors, viral proteins, homeoproteins, and others. Many such translocating proteins, or parts of them, appear to be able to carry with them cargo into the cell, and a basic sequence from the HIV-1 Tat protein has been reported to provide intracellular delivery of several fused proteins. For evaluating the efficiency of translocation to the cytosol, this TAT-peptide was fused to the diphtheria toxin A-fragment (dtA), an extremely potent inhibitor of protein synthesis which normally is delivered efficiently to the cytosol by the toxin B-fragment. The fusion of the TAT-peptide to dtA converted the protein to a heparin-binding protein that bound avidly to the cell surface. However, no cytotoxicity of this protein was detected, indicating that the TAT-peptide is unable to efficiently deliver enzymatically active dtA to the cytosol. Interestingly, the fused TAT-peptide potentiated the binding and cytotoxic effect of the corresponding holotoxin. We made a fusion protein between VP22, another membrane-permeant protein, and dtA, and also in this case we detected association with cells in the absence of a cytotoxic effect. The data indicate that transport of dtA into the cell by the TAT-peptide and VP22 is inefficient.
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Specific Killing of HIV-infected Lymphocytes by a Recombinant Immunotoxin Directed against the HIV-1 Envelope Glycoprotein. Mol Med 1998. [DOI: 10.1007/bf03401745] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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18
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Van Oijen MG, Preijers FW. Rationale for the use of immunotoxins in the treatment of HIV-infected humans. J Drug Target 1998; 5:75-91. [PMID: 9588864 DOI: 10.3109/10611869808995861] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The first step in the replication of human immunodeficiency virus (HIV) is selective binding of the envelope glycoprotein (gp120) to CD4 receptors on T cells or macrophages. After penetration in these cells, the genome of the virus is integrated in the human genome. HIV-infection causes depletion of CD4-positive cells resulting in a severe immunosuppression. It is believed that eliminating HIV-infected cells is crucial in limiting further reduction of CD4-positive cells and thus, preventing disease progression. The most commonly used drugs, such as zidovudine (AZT), appeared to be not completely effective. Therefore many investigators are searching for alternative treatment modalities. The use of immunotoxins (ITs) to eliminate HIV-infected cells is discussed. ITs are chimeric molecules in which cell-binding ligands are coupled to toxins and can specifically eliminate undesired cells. The cell-binding carriers of anti-HIV ITs have been directed against different regions of the HIV envelope glycoprotein (gp120 and gp41) and surface antigens (e.g CD4, CD25). The ITs have been composed of different ribosome-inactivating proteins (RIPs) like pokeweed antiviral protein (PAP), Pseudomonas exotoxin (PE), Diphtheria toxin (DT), or ricin. In in vitro studies, several of these ITs have been shown to be effective and specific in killing acute and persistently HIV-infected cells. The ITs were effective at concentrations (ID50 range from 10(-9) M to 10(-12) M) that were not toxic to uninfected cells or cells without the antigen. The IT CD4(178)PE40, a fusion protein directed against the CD4 binding site of gp120, has been investigated in two in vivo trials. The results were disappointing considering the antiviral activity in vitro. This was thought to be due to the rapid clearance of the IT and the differential resistance of clinical HIV isolates. Use of a panel of ITs is likely to be more effective because multiple approaches cover the intrinsic variability of HIV and the presence of IT-resistant or latently infected cells, as well as the blocking presence of neutralizing anti-HIV antibodies and the immunogenicity of most ITs. It may be possible to control the virus completely with a panel of ITs in combination with other antiviral or immunosuppressive agents such as RT inhibitors (e.g AZT), interferon alpha, or cyclosporine. More research will be necessary to develop such a combined therapy.
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Affiliation(s)
- M G Van Oijen
- Department of Hematology, University Hospital St. Radboud, Nijmegen, The Netherlands
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19
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Mori T, Shoemaker RH, McMahon JB, Gulakowski RJ, Gustafson KR, Boyd MR. Construction and enhanced cytotoxicity of a [cyanovirin-N]-[Pseudomonas exotoxin] conjugate against human immunodeficiency virus-infected cells. Biochem Biophys Res Commun 1997; 239:884-8. [PMID: 9367864 DOI: 10.1006/bbrc.1997.7505] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cyanovirin-N (CV-N) is a novel 11-kDa anti-HIV(human immunodeficiency virus) protein that binds with high affinity to the viral envelope glycoprotein gp120. In contrast to soluble CD4 and most known neutralizing antibodies that bind gp120, CV-N exerts potent anti-viral activity against primary clinical HIV isolates as well as laboratory-adapted strains of HIV. Here we describe the recombinant production, purification, and characterization of a chimeric toxin molecule, FLAG-CV-N-PE38, that contains CV-N as a gp120-targeting moiety linked to the translocation and cytotoxic domains of Pseudomonas exotoxin A. FLAG-CV-N-PE38 showed enhanced cytotoxicity to HIV-infected, gp120-expressing H9 cells compared to uninfected H9 cells. Competition experiments with free CV-N provided further support that the enhanced FLAG-CV-N-PE38-induced cytotoxicity was due to interactions of the CV-N moiety with cell surface gp120. This study establishes the feasibility of use of CV-N as a gp120-targeting sequence for construction and experimental therapeutic investigations of unique new chimeric toxins designed to selectively destroy HIV-infected host cells.
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Affiliation(s)
- T Mori
- Laboratory of Drug Discovery Research and Development, National Cancer Institute, Frederick, Maryland 21702-1201, USA
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20
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Schnell MJ, Johnson JE, Buonocore L, Rose JK. Construction of a novel virus that targets HIV-1-infected cells and controls HIV-1 infection. Cell 1997; 90:849-57. [PMID: 9298897 DOI: 10.1016/s0092-8674(00)80350-5] [Citation(s) in RCA: 174] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We describe a recombinant vesicular stomatitis virus lacking its glycoprotein gene and expressing instead the HIV-1 receptor CD4 and a coreceptor, CXCR4. This virus was unable to infect normal cells but did infect, propagate on, and kill cells that were first infected with HIV-1 and therefore had the HIV membrane fusion protein on their surface. Killing of HIV-1-infected cells controlled HIV infection in a T cell line and reduced titers of infectious HIV-1 in the culture by as much as 10(4)-fold. Such a targeted virus could have therapeutic value in reducing HIV viral load. Our results also demonstrate a general strategy of targeting one virus to the envelope protein of another virus to control infection.
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Affiliation(s)
- M J Schnell
- Department of Pathology, Yale University School of Medicine, New Haven, Connecticut 06510, USA
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21
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Wu M. Are immunoconjugates useful for therapy with autoimmune diseases? INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 1997; 19:83-93. [PMID: 9278178 DOI: 10.1016/s0192-0561(97)00012-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Immunoconjugates or immunotoxins (ITs) are targeting molecules which consist of a monoclonal antibody together with a toxin--thereby they can selectively kill target cells in a highly efficient manner. The use of ITs as a drug targeting approach is one of the most attractive research fields for tumor therapy; however, the study of ITs for the treatment of autoimmune diseases has been given little attention until recently. It has been shown that ITs could help alleviate the symptoms of myasthenia gravis and rheumatoid arthritis in animal models. In the last 3 yr ITs have been used in clinical trials (phase I and phase II) for the treatment of various autoimmune diseases including rheumatoid arthritis, systemic lupus erythematosus, insulin-dependent diabetes mellitus and psoriasis. This article reviews the main progress on the application of ITs for the therapies of autoimmune diseases. The preliminary results suggest the future may hold some promise, but side effects, in addition to there being no convincing efficacy, remain unresolved.
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Affiliation(s)
- M Wu
- Department of Biology, University of Leeds, U.K.
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22
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Pincus SH, Wehrly K, Cole R, Fang H, Lewis GK, McClure J, Conley AJ, Wahren B, Posner MR, Notkins AL, Tilley SA, Pinter A, Eiden L, Teintze M, Dorward D, Tolstikov VV. In vitro effects of anti-HIV immunotoxins directed against multiple epitopes on HIV type 1 envelope glycoprotein 160. AIDS Res Hum Retroviruses 1996; 12:1041-51. [PMID: 8827220 DOI: 10.1089/aid.1996.12.1041] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We have used a panel of anti-gp160 MAbs to construct anti-HIV immunotoxins by coupling antibodies to ricin A chain (RAC). The ability of the immunotoxins to kill HIV-1-infected cells and halt the spread of infection was tested in tissue culture on persistently and acutely infected cell lines and primary lymphocyte cultures stimulated with phytohemagglutinin (PHA blasts). Laboratory strains and clinical isolates of HIV both were tested. The constitution and antigen-binding capacity of the immunotoxins were confirmed by ELISA and indirect immunofluorescence. Immunotoxins that bind epitopes exposed on the cell surface effectively killed persistently infected cells, although killing was not directly proportional to binding of immunotoxin to cell. The activity of anti-gp41, but not anti-gp120, immunotoxins was markedly enhanced in the presence of soluble CD4 or peptides corresponding to the CDR3 region of CD4. CD4-mediated enhancement of anti-gp41 immunotoxin activity was observed for laboratory strains neutralized by sCD4 and for clinical isolates that were resistant to neutralization by sCD4. Immunotoxin action was potentiated by brefeldin A, bafilomycin A1, cortisone, and an amphipathic fusion peptide, but not by cytochalasin D, nocodazol, monodansyl cadaverine, or trans-retinoic acid. Anti-HIV immunotoxins are useful tool with which to study the functional expression of gp120/gp41 antigens on the surface of HIV-infected cells, as well as potential AIDS therapeutics. Because these studies relate to the accessibility of viral antigens to antibody-mediated attack, these studies also have relevance for vaccine development.
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Affiliation(s)
- S H Pincus
- Laboratory of Microbial Structure and Function, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana 59840, USA
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23
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Barnett BB, Smee DF, Malek SM, Sidwell RW. Selective cytotoxicity towards cytomegalovirus-infected cells by immunotoxins consisting of gelonin linked to anti-cytomegalovirus antibody. Antiviral Res 1995; 28:93-100. [PMID: 8585763 DOI: 10.1016/0166-3542(95)00034-j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An immunotoxin specific for cells infected with human cytomegalovirus (HCMV) was constructed by attaching the ribosome-inactivating enzyme, gelonin, through a disulfide linkage to polyclonal human immunoglobulin (IgG). In uninfected cells, there was no difference between [35S]methionine incorporation in untreated cultures and those treated with immunotoxin at 100 micrograms/ml. In HCMV-infected cells, there was a significant decrease in [35S]methionine incorporation in the immunotoxin-treated cultures, suggesting a selective cytotoxic effect on the virus-infected cells. An immunotoxin specific for murine cytomegalovirus (MCMV) was prepared by linking gelonin to polyclonal anti-MCMV IgG. Using this same parameter for assay of cytotoxicity, the anti-MCMV immunotoxin had a 50% cytotoxic concentration of 35 micrograms/ml in MCMV-infected cells and greater than 200 micrograms/ml in uninfected cells. MCMV yields measured at 7 days postinoculation were reduced by 2 log10 in cultures treated with immunotoxin at 20 micrograms/ml at 1 day postinoculation. These data suggest immunotoxins may have potential for eliminating CMV-infected cells from the host.
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Affiliation(s)
- B B Barnett
- Institute for Antiviral Research, Utah State University, Logan 84322-5500, USA
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24
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al-Jaufy AY, King SR, Jackson MP. Purification and characterization of a Shiga toxin A subunit-CD4 fusion protein cytotoxic to human immunodeficiency virus-infected cells. Infect Immun 1995; 63:3073-8. [PMID: 7622233 PMCID: PMC173419 DOI: 10.1128/iai.63.8.3073-3078.1995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
In a previous paper, we reported that a chimeric toxin composed of the enzymatic domain of the Shiga toxin A polypeptide (StxA1) genetically fused to the human CD4 (hCD4) molecule selectively kills cells infected with human immunodeficiency virus type 1 (HIV-1). Although other hCD4-containing chimeras cytotoxic to HIV-infected cells have been developed, there is limited information regarding their receptor binding and internalization. Therefore, the goals of this study were to purify the StxA1-hCD4 fusion protein, identify the receptor(s), and investigate the cytosolic trafficking route used by the chimeric toxin. Sufficient quantities of the StxA1-hCD4 hybrid were isolated for this investigation by using the pET expression and purification system. Cos-1 cells were rendered sensitive to the StxA1-hCD4 chimera by transfection with the env gene, which encodes HIV-1 envelope glycoproteins. The entry and translocation pathway used by the StxA1-hCD4 hybrid toxin was investigated by assessing the protective capacities of chemical reagents which interfere with microfilament movement, acidification of endosomes, and the integrity of the Golgi apparatus. Our findings indicated that the chimera uses HIV-1 glycoprotein gp120, and perhaps gp41, as a receptor which directs its entry through receptor cycling. Uptake is pH independent, and the StxA1-hCD4 hybrid is apparently translocated to the Golgi complex as with other bipartite toxins.
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Affiliation(s)
- A Y al-Jaufy
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, Michigan 48201, USA
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25
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Norkin LC. Virus receptors: implications for pathogenesis and the design of antiviral agents. Clin Microbiol Rev 1995; 8:293-315. [PMID: 7621403 PMCID: PMC172860 DOI: 10.1128/cmr.8.2.293] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
A virus initiates infection by attaching to its specific receptor on the surface of a susceptible host cell. This prepares the way for the virus to enter the cell. Consequently, the expression of the receptor on specific cells and tissues of the host is a major determinant of the route of entry of the virus into the host and of the patterns of virus spread and pathogenesis in the host. This review emphasizes the virus-receptor interactions of human immunodeficiency virus, the rhinoviruses, the herpesviruses, and the coronaviruses. These interactions are often found to be complex and dynamic, involving multiple sites or factors on both the virus and the host cell. Also, the receptor may play an important role in virus entry per se in addition to its role in virus binding. In the cases of human immunodeficiency virus and the rhinoviruses, ingenious approaches to therapeutic strategies based on inhibiting virus attachment and entry are under development and in clinical trials.
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Affiliation(s)
- L C Norkin
- Department of Microbiology, University of Massachusetts, Amherst 01003, USA
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26
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Pincus SH, Tolstikov VV. Anti-human immunodeficiency virus immunoconjugates. ADVANCES IN PHARMACOLOGY (SAN DIEGO, CALIF.) 1995; 32:205-47. [PMID: 7748796 DOI: 10.1016/s1054-3589(08)61014-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- S H Pincus
- Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA
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27
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Flasher D, Konopka K, Chamow SM, Dazin P, Ashkenazi A, Pretzer E, Düzgünes N. Liposome targeting to human immunodeficiency virus type 1-infected cells via recombinant soluble CD4 and CD4 immunoadhesin (CD4-IgG). BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1194:185-96. [PMID: 8075135 DOI: 10.1016/0005-2736(94)90219-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
HIV-infected cells producing virions express the viral envelope glycoprotein gp120/gp41 on their surface. We examined whether liposomes coupled to recombinant soluble CD4 (sCD4, the ectodomain of CD4 which binds gp120 with high affinity) could specifically bind to HIV-infected cells. sCD4 was chemically coupled by 2 different methods to liposomes containing rhodamine-phosphatidylethanolamine in their membrane as a fluorescent marker. In one method, sCD4 was thiolated with N-succinimidyl acetylthioacetate (SATA) and coupled to liposomes via a maleimide-derivatised phospholipid. In the other method, the oligosaccharides on sCD4 were coupled to a sulfhydryl-derivatised phospholipid, utilizing the bifunctional reagent, 4-(4-N-maleimidophenyl)butyric acid hydrazide (MPBH). The association of the liposomes with HIV-1-infected or uninfected cells was examined by flow cytometry. CD4-coupled liposomes associated specifically to chronically infected H9/HTLV-IIIB cells, but not to uninfected H9 cells. CD4-coupled liposomes also associated specifically with monocytic THP-1 cells chronically infected with HIV-1 (THP-1/HIV-1IIIB). Control liposomes without coupled CD4 did not associate significantly with any of the cells, while free sCD4 could competitively inhibit the association of the CD4-coupled liposomes with the infected cells. The chimeric molecule CD4-immunoadhesin (CD4-IgG) could also be used as a ligand to target liposomes with covalently coupled Protein A (which binds the Fc region of the CD4-IgG) to H9/HTLV-IIIB cells. The CD4-liposomes inhibited the infectivity of HIV-1 in A3.01 cells, and also bound rgp120. Our results suggest that liposomes containing antiviral or cytotoxic agents may be targeted specifically to HIV-infected cells.
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Affiliation(s)
- D Flasher
- Department of Microbiology, School of Dentistry, University of the Pacific, San Francisco, CA 94115-2399
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28
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Pincus SH. Is there a role for immunoconjugates in the treatment of AIDS? Expert Opin Investig Drugs 1994. [DOI: 10.1517/13543784.3.8.799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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29
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Youle RJ, Wu YN, Mikulski SM, Shogen K, Hamilton RS, Newton D, D'Alessio G, Gravell M. RNase inhibition of human immunodeficiency virus infection of H9 cells. Proc Natl Acad Sci U S A 1994; 91:6012-6. [PMID: 8016107 PMCID: PMC44127 DOI: 10.1073/pnas.91.13.6012] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Onconase and bovine seminal RNase, two members of the RNase A superfamily, inhibit human immunodeficiency virus type 1 replication in H9 leukemia cells 90-99.9% over a 4-day incubation at concentrations not toxic to uninfected H9 cells. Two other members of the same protein family, bovine pancreatic RNase A and human eosinophil-derived neurotoxin, have no detectable antiviral activity, demonstrating a strikingly selective antiviral activity among homologous ribonucleases. The antiviral RNases do not appear to affect viral particles directly but inhibit replication in host cell cultures. Onconase, already in clinical trials for cancer therapy, and bovine seminal RNase have potential as antiviral therapeutics.
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Affiliation(s)
- R J Youle
- Biochemistry Section, Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892
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30
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Molema G, Meijer D. Targeting of drugs to various blood cell types using (neo-)glycoproteins, antibodies and other protein carriers. Adv Drug Deliv Rev 1994. [DOI: 10.1016/0169-409x(94)90004-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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31
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al-Jaufy AY, Haddad JE, King SR, McPhee RA, Jackson MP. Cytotoxicity of a shiga toxin A subunit-CD4 fusion protein to human immunodeficiency virus-infected cells. Infect Immun 1994; 62:956-60. [PMID: 8112869 PMCID: PMC186209 DOI: 10.1128/iai.62.3.956-960.1994] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Shiga toxin (STX) is a ribosome-inactivating cytotoxin produced by Shigella dysenteriae serotype 1. The enzymatic domain of the STX A polypeptide has been defined by introducing amino- and carboxy-terminal deletions in the polypeptide and assessing activity in a cell-free translation system. Three recombinant forms of StxA which possess enzymatic activity were genetically fused to a 165-amino-acid polypeptide derived from CD4, the cellular receptor for human immunodeficiency virus type 1 (HIV-1). This strategy eliminated the STX receptor-binding subunit and directed the hybrid toxins to cells expressing the HIV-1 surface glycoprotein gp120. A bacterial lysate containing these toxin chimeras killed the HIV-1-infected T-cell line 8E5 but was not cytotoxic toward the uninfected parental cell line A3.01. This cytotoxic activity was specifically inhibited by monoclonal antibodies which block the interaction between CD4 and gp120. These StxA-CD4 hybrids add to the repertoire of recombinant fusion proteins which possess the capacity to selectively kill HIV-1-infected T cells.
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Affiliation(s)
- A Y al-Jaufy
- Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, Michigan 48201
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32
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Barbieri L, Battelli MG, Stirpe F. Ribosome-inactivating proteins from plants. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1154:237-82. [PMID: 8280743 DOI: 10.1016/0304-4157(93)90002-6] [Citation(s) in RCA: 546] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- L Barbieri
- Dipartimento di Patologia Sperimentale, Università di Bologna, Italy
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33
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Wachinger M, Samtleben R, Gerhäuser C, Wagner H, Erfle V. Bryodin, a single-chain ribosome-inactivating protein, selectively inhibits the growth of HIV-1-infected cells and reduces HIV-1 production. RESEARCH IN EXPERIMENTAL MEDICINE. ZEITSCHRIFT FUR DIE GESAMTE EXPERIMENTELLE MEDIZIN EINSCHLIESSLICH EXPERIMENTELLER CHIRURGIE 1993; 193:1-12. [PMID: 8446767 DOI: 10.1007/bf02576205] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Bryodin, a single-chain ribosome-inactivating protein (RIP) isolated from Bryonia cretica ssp dioica (cucurbitaceae), was found to selectively inhibit the growth of persistently HIV-1-infected T lymphoma cells (KE37/1) and human lung fibroblast when used in concentrations from 2-20 micrograms/ml. Uninfected KE37/1 cells remained unaffected at the same doses of bryodin. In addition, bryodin reduced HIV production in the surviving infected cells. Two isoforms of bryodin were purified by dye ligand chromatography. Both isoforms exerted the growth-inhibiting influence and reduced HIV production. Trichosanthin, another member of the RIP family, had similar inhibitory effects on the growth of HIV-1 infected cells and on HIV-1 production. Bryodin and trichosanthin were effective in about the same dose range. No selective effects for HIV-infected cells were observed with the RIPs gelonin and ricin.
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Affiliation(s)
- M Wachinger
- Institut für Molekulare Virologie, GSF Forschungszentrum für Umwelt und Gesundheit, Neuherberg, Federal Republic of Germany
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34
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Winters MA, Merigan TC. Continuous presence of CD4-PE40 is required for antiviral activity against single-passage HIV isolates and infected peripheral blood mononuclear cells. AIDS Res Hum Retroviruses 1993; 9:1091-6. [PMID: 8312052 DOI: 10.1089/aid.1993.9.1091] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
CD4-PE40, a recombinant protein consisting of a portion of human CD4 linked to Pseudomonas aeruginosa exotoxin, was studied in vitro to assess its ability to inhibit the replication of primary isolates of HIV. CD4-PE40 was added to cultures of phytohemagglutin (PHA)-stimulated normal peripheral blood mononuclear cells (PBMCs) infected either with the laboratory strain HIVIIIb or single-passage virus stocks derived from patient PBMCs. Results showed that the replication of HIVIIIb was inhibited by a single pulse of CD4-PE40 and, more significantly, by continuous exposure to the drug. The replication of primary virus isolates, however, was inhibited only by continuous exposure to CD4-PE40. Cultures of freshly isolated PBMCs from HIV-seropositive individuals that were directly treated with CD4-PE40 before culture also required the continuous presence of drug to demonstrate inhibition of HIV replication. These results suggest that continuous administration of CD4-PE40 may be required to produce a significant anti-HIV effect in vivo.
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Affiliation(s)
- M A Winters
- Center for AIDS Research, Stanford University Medical Center, California 94305
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35
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Girbés T, Citores L, Iglesias R, Ferreras J, Muñoz R, Rojo M, Arias F, García J, Méndez E, Calonge M. Ebulin 1, a nontoxic novel type 2 ribosome-inactivating protein from Sambucus ebulus L. leaves. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(17)46829-3] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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36
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Affiliation(s)
- V St Georgiev
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892
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37
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Bell KD, Ramilo O, Vitetta ES. Combined use of an immunotoxin and cyclosporine to prevent both activated and quiescent peripheral blood T cells from producing type 1 human immunodeficiency virus. Proc Natl Acad Sci U S A 1993; 90:1411-5. [PMID: 8434001 PMCID: PMC45883 DOI: 10.1073/pnas.90.4.1411] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Two different populations of infected T cells are present in human immunodeficiency virus (HIV)-infected individuals: activated cells that produce virions and quiescent cells that harbor the viral genome but are unable to produce virus unless they are activated. Using an in vitro model of acute HIV infection, we have evaluated the effect of depleting activated T cells with an immunotoxin and subsequently inhibiting activation of quiescent T cells with an immunosuppressive agent. CD25 (Tac, p55), the alpha chain of the interleukin 2 receptor, is expressed on activated, but not quiescent, T cells. An anti-CD25-ricin A chain immunotoxin eliminated activated, CD25+ HIV-infected cells and, thereby, inhibited viral production by these cells. Subsequent addition of cyclosporine to the residual CD25- cells prevented their activation and thereby suppressed their ability to produce virus and to propagate the infection to uninfected T cells.
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Affiliation(s)
- K D Bell
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
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38
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Harrison GS, Long CJ, Castillo I. Effects of enhancer mutations on the expression of human immunodeficiency virus 1-regulated luciferase and diphtheria toxin A chain genes in transfected cells. Toxicon 1993; 31:85-90. [PMID: 8446966 DOI: 10.1016/0041-0101(93)90360-u] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This study explores human immunodeficiency virus 1 (HIV-1)-regulated diphtheria toxin A (DT-A) gene expression as a means of eradicating HIV-infected cells. Previously, we constructed luciferase and DT-A plasmids, containing cis-acting Tat and Rev responsive elements, which showed low basal expression and required both Tat and Rev for maximal expression. Cell lines which had stably integrated the DT-A constructs were resistant to HIV production. To reduce toxicity due to basal expression, this study investigates the effect of mutations in the HIV enhancer on expression of luciferase and DT-A plasmids. Some mutations were found to substantially reduce basal expression while still allowing for trans-activation. Such mutations, in combination with attenuated versions of DT-A, may make regulated toxin gene expression feasible as a therapy for AIDS.
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Affiliation(s)
- G S Harrison
- Division of Medical Oncology, University of Colorado Health Sciences Center, Denver 80262
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39
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Yamaguchi Y, Semmel M, Stanislawski L, Strosberg AD, Stanislawski M. Virucidal effects of glucose oxidase and peroxidase or their protein conjugates on human immunodeficiency virus type 1. Antimicrob Agents Chemother 1993; 37:26-31. [PMID: 8381638 PMCID: PMC187599 DOI: 10.1128/aac.37.1.26] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Glucose oxidase and peroxidase (lactoperoxidase or myeloperoxidase) are virucidal to human immunodeficiency virus type 1 (HIV-1) in the presence of sodium iodide, as assessed by the loss of viral replication in a syncytium-forming assay or by the inhibition of cytopathic effects on infected cells. In the presence of low concentrations of sodium iodide, five HIV-1 isolates were equally susceptible to this virucidal system at enzyme concentrations of a few milliunits. The loss of viral replication was linearly related to the time of incubation in the enzyme solutions, with an inactivation rate of 1 log unit every 30 min. These enzymes and this halide were also cytotoxic to chronically infected, but not to uninfected, cultured CEM cells. Protein conjugates were prepared by using the enzymes and murine antibody 105.34, which recognized the V3 loop of HIV-1 LAI isolate surface glycoprotein, or recombinant human CD4. The protein conjugates inactivated free virus at rates similar to those of the free enzymes and were more effective than antibody or recombinant CD4 alone. These in vitro findings demonstrate that the peroxidase-H2O2-halide system provides potent virucidal activity against HIV-1.
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Affiliation(s)
- Y Yamaguchi
- Laboratoire d'Immunologie, Groupe de Laboratoires de l'Institut de Recherches Scientifiques sur le Cancer, Villejuif, France
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40
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Chamow S, Kogan T, Peers D, Hastings R, Byrn R, Ashkenazi A. Conjugation of soluble CD4 without loss of biological activity via a novel carbohydrate-directed cross-linking reagent. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)49621-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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41
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Meijer DK, Jansen RW, Molema G. Drug targeting systems for antiviral agents: options and limitations. Antiviral Res 1992; 18:215-58. [PMID: 1416906 DOI: 10.1016/0166-3542(92)90058-d] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- D K Meijer
- Department of Pharmacology and Therapeutics, University Center for Pharmacy, Groningen, The Netherlands
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42
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Abstract
More than a dozen of hybrid proteins possessing reactivity with human immunodeficiency virus-type 1-(HIV-1) infected cells and cytotoxicity have been produced and studied by several groups. These proteins are prepared either by chemical cross-linking of a toxin and a carrier molecule or by expressing fused genes of the two moieties. These cytotoxic agents have been investigated to eliminate HIV-1-infected cells in vitro. The ID50 of these agents range from pM to nM. This article compares the results of the various approaches and discusses the limits and potential of immunoconjugates for AIDS therapy.
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Affiliation(s)
- Y W Kim
- Tanox Biosystems, Inc., Houston, TX 77025
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43
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Abstract
Drugs capable of inhibiting viruses in vitro were described in the 1950s, but real progress was not made until the 1970s, when agents capable of inhibiting virus-specific enzymes were first identified. The last decade has seen rapid progress in both our understanding of antiviral therapy and the number of antiviral agents on the market. Amantadine and ribavirin are available for treatment of viral respiratory infections. Vidarabine, acyclovir, ganciclovir, and foscarnet are used for systemic treatment of herpesvirus infections, while ophthalmic preparations of idoxuridine, trifluorothymidine, and vidarabine are available for herpes keratitis. For treatment of human immunodeficiency virus infections, zidovudine and didanosine are used. Immunomodulators, such as interferons and colony-stimulating factors, and immunoglobulins are being used increasingly for viral illnesses. While resistance to antiviral drugs has been seen, especially among AIDS patients, it has not become widespread and is being intensely studied. Increasingly, combinations of agents are being used: to achieve synergistic inhibition of viruses, to delay or prevent resistance, and to decrease dosages of toxic drugs. New approaches, such as liposomes carrying antiviral drugs and computer-aided drug design, are exciting and promising prospects for the future.
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Affiliation(s)
- B Bean
- Department of Pathology, Humana Hospital-Michael Reese, Chicago, Illinois 60616
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44
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London SD, Schmaljohn AL, Dalrymple JM, Rice CM. Infectious enveloped RNA virus antigenic chimeras. Proc Natl Acad Sci U S A 1992; 89:207-11. [PMID: 1370348 PMCID: PMC48205 DOI: 10.1073/pnas.89.1.207] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Random insertion mutagenesis has been used to construct infectious Sindbis virus structural protein chimeras containing a neutralization epitope from a heterologous virus, Rift Valley fever virus. Insertion sites, permissive for recovery of chimeric viruses with growth properties similar to the parental virus, were found in the virion E2 glycoprotein and the secreted E3 glycoprotein. For the E2 chimeras, the epitope was expressed on the virion surface and stimulated a partially protective immune response to Rift Valley fever virus infection in vivo. Besides providing a possible approach for developing live attenuated vaccine viruses, insertion of peptide ligands into virion surface proteins may ultimately allow targeting of virus infection to specific cell types.
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Affiliation(s)
- S D London
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110-1093
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45
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Ashorn P, Moss B, Berger EA. Therapeutic strategies employing CD4, the HIV receptor. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1992; 312:71-81. [PMID: 1514446 DOI: 10.1007/978-1-4615-3462-4_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- P Ashorn
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
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46
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47
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Pitts TW, Bohanon MJ, Leach MF, McQuade TJ, Marschke CK, Merritt JA, Wierenga W, Nicholas JA. Soluble CD4-PE40 is cytotoxic for a transfected mammalian cell line stably expressing the envelope protein of human immunodeficiency virus (HIV-1), and cytotoxicity is variably inhibited by the sera of HIV-1-infected patients. AIDS Res Hum Retroviruses 1991; 7:741-50. [PMID: 1742081 DOI: 10.1089/aid.1991.7.741] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sera were obtained from 50 individuals infected with human immunodeficiency virus type 1 or from HIV-1-uninfected individuals before or after vaccination with recombinant gp160. These sera were evaluated for activity antagonistic to the cell-killing activity of the chimeric Pseudomonas exotoxin hybrid protein, sCD4-PE40. For these studies, Chinese hamster ovary (CHO) cells were transfected with a chimeric plasmid encoding the tat, rev, and envelope genes of HIV-1 and a cell line was selected for stable expression of the envelope glycoproteins at the cell surface (CHO-env). Cytotoxicity of sCD4-PE40 for CHO-env in the presence or absence of added human serum was quantitated spectrophometrically following enzymatic reduction of a tetrazolium bromide within the mitochondria of viable cells (MTT assay). Several HIV+ sera inhibited the cytotoxic activity of sCD4-PE40; the antagonist had properties consistent with those of immunoglobulins in that it was heat stable, absorbed by protein A, and reversible by increasing the concentration of sCD4-PE40. Of 15 HIV+ sera which strongly reacted with gp120, 11 (73%) also potently inhibited sCD4-PE40 cytotoxicity, and cytotoxicity was inhibited by sera from some HIV- individuals after, but not before, immunization with gp160. These data suggested a role for antibody to gp120 in the antagonistic activity. However, not all sera with antibody to gp120 antagonized sCD4-PE40 cytotoxicity and high levels of antagonist activity were frequently (40%) found in HIV+ sera lacking immunoblot-detectable antibody to gp120, or antibody to either CD4 or PE40. Grouping of the HIV+ sera according to the patients' absolute number of CD4+ cells revealed that the degree of inhibition of sCD4-PE40 cytotoxicity approached a Gaussian distribution, suggesting that persons with CD4+ cell counts between 200 and 700/mm3 may be more likely to possess significant levels of serum antagonist. This data have implications for the clinical development of sCD4-PE40 or other sCD4-based therapeutics in the management of HIV-1 infection.
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Affiliation(s)
- T W Pitts
- Department of Cancer and Infectious Diseases, Upjohn Laboratories, Kalamazoo, MI 49007
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48
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Ashkenazi A, Smith DH, Marsters SA, Riddle L, Gregory TJ, Ho DD, Capon DJ. Resistance of primary isolates of human immunodeficiency virus type 1 to soluble CD4 is independent of CD4-rgp120 binding affinity. Proc Natl Acad Sci U S A 1991; 88:7056-60. [PMID: 1871120 PMCID: PMC52232 DOI: 10.1073/pnas.88.16.7056] [Citation(s) in RCA: 76] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The infection of human cells by laboratory strains of human immunodeficiency virus type 1 (HIV-1) can be blocked readily in vitro by recombinant soluble CD4 and CD4-immunoglobulin hybrid molecules. In contrast, infection by primary isolates of HIV-1 is much less sensitive to blocking in vitro by soluble CD4-based molecules. To investigate the molecular basis for this difference between HIV-1 strains, we isolated the gp120-encoding genes from several CD4-resistant and CD4-sensitive HIV-1 strains and characterized the CD4-binding properties of their recombinant gp120 (rgp120) products. Extensive amino acid sequence variation was found between the gp120 genes of CD4-resistant and CD4-sensitive HIV-1 isolates. However, the CD4-binding affinities of rgp120 from strains with markedly different CD4 sensitivities were essentially the same, and only small differences were observed in the kinetics of CD4 binding. These results suggest that the lower sensitivity of primary HIV-1 isolates to neutralization by CD4-based molecules is not due to lower binding affinity between soluble CD4 and free gp120.
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Affiliation(s)
- A Ashkenazi
- Department of Immunobiology, Genentech, Inc., South San Francisco, CA 94080
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49
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Ghetie V, Slaughter C, Wheeler HT, Uhr JW, Vitetta ES. CD4 peptide-protein conjugates, but not recombinant human CD4, bind to recombinant gp120 from the human immunodeficiency virus in the presence of serum from AIDS patients. Proc Natl Acad Sci U S A 1991; 88:5690-3. [PMID: 2062847 PMCID: PMC51943 DOI: 10.1073/pnas.88.13.5690] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Sera from human immunodeficiency virus-positive (HIV+; Walter Reed stage 6) individuals inhibit the interaction between recombinant human CD4 and recombinant gp120 from HIV (rCD4 and rgp120, respectively), thereby interfering with the ability of soluble rCD4 to block infection with HIV or rCD4-toxin conjugates to kill HIV-infected cells. In this report we demonstrate that the inhibitory activity of such sera is caused primarily by anti-gp120 antibodies that do not recognize the CD4 interaction site on gp120. To circumvent the problem of inhibition, we have generated a construct containing a peptide of CD4 (residues 41-84) conjugated to ovalbumin (three to five peptides per molecule). This multivalent conjugate binds to rgp120 and binding is not inhibited by antibodies in HIV+ sera.
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Affiliation(s)
- V Ghetie
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas 75235-9048
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50
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Finberg RW, Wahl SM, Allen JB, Soman G, Strom TB, Murphy JR, Nichols JC. Selective elimination of HIV-1-infected cells with an interleukin-2 receptor-specific cytotoxin. Science 1991; 252:1703-5. [PMID: 1904628 DOI: 10.1126/science.1904628] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Infection by human immunodeficiency virus type 1 (HIV-1) is associated with cellular activation and expression of the interleukin-2 (IL-2) receptor. A genetically engineered fusion toxin, DAB486 IL-2, that contains the enzymatic site and translocation domain of diphtheria toxin and the receptor binding domain of IL-2 specifically kills cells that express high-affinity IL-2 receptors. This toxin selectively eliminated the HIV-1-infected cells from mixed cultures of infected and uninfected cells and inhibited production of viral proteins and infectious virus. Thus, cellular activation antigens present a target for early antiviral intervention.
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Affiliation(s)
- R W Finberg
- Laboratory of Infectious Diseases, Dana-Farber Cancer Institute, Boston, MA
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