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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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Kumar RB, Suresh MX. A computational perspective of molecular interactions through virtual screening, pharmacokinetic and dynamic prediction on ribosome toxin A chain and inhibitors of Ricinus communis. Pharmacognosy Res 2012; 4:2-10. [PMID: 22224054 PMCID: PMC3250034 DOI: 10.4103/0974-8490.91027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/04/2011] [Accepted: 12/22/2011] [Indexed: 11/28/2022] Open
Abstract
Background: Ricin is considered to be one of the most deadly toxins and gained its favor as a bioweapon that has a serious social and biological impact, due to its widespread nature and abundant availability. The hazardous effects of this toxin in human being are seen in almost all parts of the organ system. The severe consequences of the toxin necessitate the need for developing potential inhibitors that can effectively block its interaction with the host system. Materials and Methods: In order to identify potential inhibitors that can effectively block ricin, we employed various computational approaches. In this work, we computationally screened and analyzed 66 analogs and further tested their ADME/T profiles. From the kinetic and toxicity studies we selected six analogs that possessed appropriate pharmacokinetic and dynamic property. We have also performed a computational docking of these analogs with the target. Results: On the basis of the dock scores and hydrogen bond interactions we have identified analog 64 to be the best interacting molecule. Molecule 64 seems to have stable interaction with the residues Tyr80, Arg180, and Val81. The pharmacophore feature that describes the key functional features of a molecule was also studied and presented. Conclusion: The pharmacophore features of the drugs provided suggests the key functional groups that can aid in the design and synthesis of more potential inhibitors.
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Affiliation(s)
- R Barani Kumar
- Department of Bioinformatics, Sathyabama University, Chennai, Tamil Nadu, India
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Abstract
Rationally designed anticancer agents that target cell-surface antigens or receptors represent a promising approach for treating cancer patients. However, antibodies that bind these targets are often, by themselves, non-cytotoxic. By attaching potent toxins we can dramatically improve the clinical utility of some anti-tumour antibodies. Here we describe the construction and clinical utility of several recombinant immunotoxins; each of which is composed of antibody Fv fragments fused to powerful bacterial toxins. Results from clinical trials indicate that recombinant immunotoxins and similar agents that are designed to combine antibody selectivity with toxin cell-killing potency will be useful additions to cancer therapy.
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Affiliation(s)
- Ira Pastan
- Laboratory of Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institues of Health, 37 Convent Drive, Bethesda, MD 20892-4264, USA.
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Korcheva V, Wong J, Corless C, Iordanov M, Magun B. Administration of ricin induces a severe inflammatory response via nonredundant stimulation of ERK, JNK, and P38 MAPK and provides a mouse model of hemolytic uremic syndrome. THE AMERICAN JOURNAL OF PATHOLOGY 2005; 166:323-39. [PMID: 15632024 PMCID: PMC1602309 DOI: 10.1016/s0002-9440(10)62256-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recent interest in the health consequences of ricin as a weapon of terrorism has led us to investigate the effects of ricin on cells in vitro and in mice. Our previous studies showed that depurination of the 28S rRNA by ricin results in the inhibition of translation and the coordinate activation of the stress-activated protein kinases JNK and p38 MAPK. In RAW 264.7 macrophages, ricin induced the activation of ERK, JNK, and p38 MAPK, the accumulation of mRNA encoding tumor necrosis factor (TNF)-alpha, interleukin (IL)-1, the transcription factors c-Fos, c-Jun, and EGR1, and the appearance of TNF-alpha protein in the culture medium. Using specific inhibitors of MAPKs, we demonstrated the nonredundant roles of the individual MAPKs in mediating proinflammatory gene activation in response to ricin. Similarly, the intravenous administration of ricin to mice led to the activation of ERK, JNK, and p38 MAPK in the kidneys, and increases in plasma-borne TNF-alpha, IL-1beta, and IL-6. Ricin-injected mice developed the hallmarks of hemolytic uremic syndrome, including thrombotic microangiopathy, hemolytic anemia, thrombocytopenia, and acute renal failure. Microarray analyses demonstrated a massive proinflammatory transcriptional response in the kidneys, coincidental with the symptoms of hemolytic uremic syndrome. Therapeutic management of the inflammatory response may affect the outcome of intoxication by ricin.
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Affiliation(s)
- Veselina Korcheva
- Department of Cell and Developmental Biology, Oregon Health and Science University, 3181 SW Sam Jackson Park Rd., Portland, OR 97239, USA
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Castelletti D, Fracasso G, Righetti S, Tridente G, Schnell R, Engert A, Colombatti M. A dominant linear B-cell epitope of ricin A-chain is the target of a neutralizing antibody response in Hodgkin's lymphoma patients treated with an anti-CD25 immunotoxin. Clin Exp Immunol 2004; 136:365-72. [PMID: 15086403 PMCID: PMC1809030 DOI: 10.1111/j.1365-2249.2004.02442.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Hodgkin's lymphoma patients treated with an anti-CD25 Ricin toxin A-chain (RTA)-based Immunotoxin (RFT5.dgA) develop an immune response against the toxic moiety of the immunoconjugate. The anti-RTA antibody response of 15 patients showing different clinical features and receiving different total amounts of RFT5.dgA was therefore studied in detail, considering antibody titre, IgG and IgM content, average binding efficacy and ability to inhibit in vitro the cytotoxicity of a RTA-based Immunotoxin. No correlations were found between these parameters and the clinical features of the patients or the total amount of Immunotoxin administered. However, using a peptide scan approach we have identified a continuous epitope recognized by all patients studied, located within the stretch L161-I175 of the RTA primary sequence, close to a previously identified T-cell epitope. The ability of anti-L161-I175 antibodies to recognize folded RTA and to affect the biological activity of RTA by inhibiting RTA-IT cytotoxicity in vitro revealed that they may exert an important role in IT neutralization in vivo. Discovery of RTA immunodominant epitopes which are the target of anti-RTA immune response may lead to the development of immunomodulating strategies and to more successful treatment schedules.
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Affiliation(s)
- D Castelletti
- Section of Immunology, Department of Pathology, University of Verona, Italy
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