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Studies in a Murine Model Confirm the Safety of Griffithsin and Advocate Its Further Development as a Microbicide Targeting HIV-1 and Other Enveloped Viruses. Viruses 2016; 8:v8110311. [PMID: 27869695 PMCID: PMC5127025 DOI: 10.3390/v8110311] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Accepted: 11/04/2016] [Indexed: 11/17/2022] Open
Abstract
Griffithsin (GRFT), a lectin from Griffithsia species, inhibits human immunodeficiency virus-1 (HIV-1) replication at sub-nanomolar concentrations, with limited cellular toxicity. However, in vivo safety of GRFT is not fully understood, especially following parenteral administration. We first assessed GRFT’s effects in vitro, on mouse peripheral blood mononuclear cell (mPBMC) viability, mitogenicity, and activation using flow-cytometry, as well as cytokine secretion through enzyme-linked immunosorbent assay (ELISA). Toxicological properties of GRFT were determined after a single subcutaneous administration of 50 mg/kg or 14 daily doses of 10 mg/kg in BALB/c mice. In the context of microbicide development, toxicity of GRFT at 2 mg/kg was determined after subcutaneous, intravaginal, and intraperitoneal administrations, respectively. Interestingly, GRFT caused no significant cell death, mitogenicity, activation, or cytokine release in mPBMCs, validating the usefulness of a mouse model. An excellent safety profile for GRFT was obtained in vivo: no overt changes were observed in animal fitness, blood chemistry or CBC parameters. Following GRFT treatment, reversible splenomegaly was observed with activation of certain spleen B and T cells. However, spleen tissues were not pathologically altered by GRFT (either with a single high dose or chronic doses). Finally, no detectable toxicity was found after mucosal or systemic treatment with 2 mg/kg GRFT, which should be further developed as a microbicide for HIV prevention.
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van Gijn R, Zuidema X, Bult A, Beijnen JH. Protein kinase C as a target for new anti-cancer agents. J Oncol Pharm Pract 2016. [DOI: 10.1177/107815529900500402] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cancer joins the category of diseases involving abnormalities in the rate of proliferation of cells and is associated with uncontrolled cell division, where cells either generate their own growth-promoting stimuli or neighboring cells or do not respond to growth inhibitory signals. Protein kinase C (PKC) is one of the key elements in the tumor growth signal transduction pathways and is found to be overexpressed in several malignant cell types. A way to control cell proliferation and cell differentiation is by influencing signal transduction pathways by modulation of PKC. PKC encloses 12 different isoenzymes, and each isoenzyme is found to have a different functional property. Because specific PKC isoenzyme types are present in different (malignant) cell species, they may be an attractive target in the development of anti-cancer agents. Classification and identification of the available PKC isoenzymes in different tumor cells could be useful in targeting specific tumors. PKC also tends to be overexpressed in association with the multidrug resistance pheno-type. This concise review deals with the role of PKC isoenzymes in (tumor) cell biology and evaluates the antineoplastic agents interacting on PKC isoenzymes.
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Affiliation(s)
- Roel van Gijn
- Department of Pharmacy and Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Xander Zuidema
- Department of Pharmaceutical Analysis and Toxicology, Faculty of Pharmacy, Utrecht University, Utrecht, The Netherlands
| | - Auke Bult
- Department of Pharmaceutical Analysis and Toxicology, Faculty of Pharmacy, Utrecht University, Utrecht, The Netherlands
| | - Jos H. Beijnen
- Department of Pharmacy and Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Amsterdam, The Netherlands, Department of Pharmaceutical Analysis and Toxicology, Faculty of Pharmacy, Utrecht University, Utrecht, The Netherlands
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Buehler DC, Marsden MD, Shen S, Toso DB, Wu X, Loo JA, Zhou ZH, Kickhoefer VA, Wender PA, Zack JA, Rome LH. Bioengineered vaults: self-assembling protein shell-lipophilic core nanoparticles for drug delivery. ACS NANO 2014; 8:7723-32. [PMID: 25061969 PMCID: PMC4148163 DOI: 10.1021/nn5002694] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 07/25/2014] [Indexed: 05/22/2023]
Abstract
We report a novel approach to a new class of bioengineered, monodispersed, self-assembling vault nanoparticles consisting of a protein shell exterior with a lipophilic core interior designed for drug and probe delivery. Recombinant vaults were engineered to contain a small amphipathic α-helix derived from the nonstructural protein 5A of hepatitis C virus, thereby creating within the vault lumen a lipophilic microenvironment into which lipophilic compounds could be reversibly encapsulated. Multiple types of electron microscopy showed that attachment of this peptide resulted in larger than expected additional mass internalized within the vault lumen attributable to incorporation of host lipid membrane constituents spanning the vault waist (>35 nm). These bioengineered lipophilic vaults reversibly associate with a sample set of therapeutic compounds, including all-trans retinoic acid, amphotericin B, and bryostatin 1, incorporating hundreds to thousands of drug molecules per vault nanoparticle. Bryostatin 1 is of particular therapeutic interest because of its ability to potently induce expression of latent HIV, thus representing a preclinical lead in efforts to eradicate HIV/AIDS. Vaults loaded with bryostatin 1 released free drug, resulting in activation of HIV from provirus latency in vitro and induction of CD69 biomarker expression following intravenous injection into mice. The ability to preferentially and reversibly encapsulate lipophilic compounds into these novel bioengineered vault nanoparticles greatly advances their potential use as drug delivery systems.
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Affiliation(s)
- Daniel C. Buehler
- Department of Biological Chemistry, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry, Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Matthew D. Marsden
- Department of Medicine, Division of Hematology and Oncology, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Sean Shen
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Daniel B. Toso
- Department of Microbiology, Immunology, & Molecular Genetics, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Xiaomeng Wu
- Department of Microbiology, Immunology, & Molecular Genetics, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Joseph A. Loo
- Department of Biological Chemistry, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, United States
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, California 90095, United States
- UCLA−DOE Institute for Genomics and Proteomics, University of California Los Angeles, Los Angeles, California 90095, United States
| | - Z. Hong Zhou
- Department of Microbiology, Immunology, & Molecular Genetics, University of California Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute at University of California Los Angeles, Los Angeles, California 90095, United States
| | - Valerie A. Kickhoefer
- Department of Biological Chemistry, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, United States
| | - Paul A. Wender
- Department of Chemistry, Department of Chemical and Systems Biology, Stanford University, Stanford, California 94305, United States
| | - Jerome A. Zack
- Department of Microbiology, Immunology, & Molecular Genetics, University of California Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute at University of California Los Angeles, Los Angeles, California 90095, United States
- Address correspondence to ;
| | - Leonard H. Rome
- Department of Biological Chemistry, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California 90095, United States
- California NanoSystems Institute at University of California Los Angeles, Los Angeles, California 90095, United States
- Address correspondence to ;
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4
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Morgan CD, Holguin MH. Chemotherapeutic stress mediated by certain antitumor antibiotics induces an atypical CD69+ surface phenotype in peripheral T-lymphocytes. Int Immunopharmacol 2002; 2:367-80. [PMID: 11811939 DOI: 10.1016/s1567-5769(01)00162-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Surface antigen CD69 is a Type II integral membrane protein that is generally considered a cell activation marker expressed very early in the normal lymphocyte activation cascade. The conformation of this surface antigen suggests a putative role in transmembrane signal transduction, yet the precise function of this surface antigen has not been clearly elucidated. We had previously reported robust atypical CD69 expression in peripheral T-lymphocytes as concentration-dependent, phenotypic responses to actinomycin D-induced chemotherapeutic stress in the absence of secondary stimulation. Additional antitumor antibiotics were evaluated for inductive potential, and the incidence and respective magnitudes of this chemotherapeutic stress-induced shift in lymphocytic CD69 expression were assessed. Results indicated that atypical CD69 expression is a common response to chemotherapy drug-induced stress. Differences in the respective percentages of CD69 + T-lymphocytes, and the resulting numbers of CD69 surface antigens ultimately expressed by these cells, were documented following in vitro drug exposure. The effective drug concentrations required to mediate detectable shifts in the CD69+ phenotype differed among the selected drugs, as well, suggesting a concentration-dependent induction mechanism putatively related to drug modality. Static CD69 expression responses in CD3+ peripheral T-lymphocytes were also documented, which further suggests that the different intracellular modalities do not mediate proportional T-lymphocyte responses through elevated CD69 expression.
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MESH Headings
- Antibiotics, Antineoplastic/adverse effects
- Antibodies, Blocking/pharmacology
- Antibodies, Monoclonal/pharmacology
- Antigens, CD/biosynthesis
- Antigens, CD/immunology
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Antigens, Differentiation, T-Lymphocyte/immunology
- Bleomycin/adverse effects
- Dactinomycin/adverse effects
- Dose-Response Relationship, Drug
- Humans
- Immunophenotyping
- Lectins, C-Type
- Mannitol/adverse effects
- Mitomycin/adverse effects
- Mitoxantrone/adverse effects
- Plicamycin/adverse effects
- Plicamycin/analogs & derivatives
- Spectrometry, Fluorescence
- Stress, Physiological/chemically induced
- T-Lymphocytes/drug effects
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Thymidine/antagonists & inhibitors
- Thymidine/metabolism
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Affiliation(s)
- C D Morgan
- Department of Pathology, Scott & White Memorial Hospital and Clinic, Scott, Sherwood, and Brindley Foundation, Texas A&M University System Health Science Center, Temple 76508, USA.
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Kos FJ, Cornell DL, Lipke AB, Graham LJ, Bear HD. Protective role of IL-2 during activation of T cells with bryostatin 1. INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 2000; 22:645-52. [PMID: 10988359 DOI: 10.1016/s0192-0561(00)00027-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Pharmacologic agents such as bryostatin 1 (bryostatin) can regulate cell activation, growth, and differentiation by modulating the activities of protein kinase C isoenzymes. Inhibition of growth of tumor cells and activation of T lymphocytes in vitro are the most recognized consequences of bryostatin treatment. The effect of bryostatin on T cells ranges from induction of apoptotic cell death to T cell activation, expansion, and acquisition of antigen-specific effector functions. Here, we describe the conditions under which these wide ranging effects occur. Mouse mammary tumor 4TO7-IL-2-primed lymph node cells exposed ex vivo to bryostatin upregulated CD25 expression but lost the ability to secrete IL-2. Most of these cells died by apoptosis unless IL-2 was provided for the duration of bryostatin treatment. Analysis of T cell repertoire by screening of T cells for the expression of different Vbeta T cell receptor (TCR) families revealed that bryostatin-induced T cell death was unbiased and Vbeta-nonspecific. Within particular Vbeta clones, only CD25(+) T cells survived exposure to bryostatin and IL-2. Treatment of 4TO7 tumor-bearing mice with a single injection of low dose bryostatin followed by multiple low doses of IL-2, but not with bryostatin alone, delayed tumor growth. These results indicate that activation of T cells with bryostatin should be carried out under protection of exogenous IL-2 to ensure survival and expansion of T cells that may exhibit anti-tumor activity.
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Affiliation(s)
- F J Kos
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA 23298, USA.
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