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Quirino M, Jakop U, Mellagi APG, Bortolozzo FP, Jung M, Schulze M. A 5-color flow cytometry panel to assess plasma membrane integrity, acrosomal status, membrane lipid organization and mitochondrial activity of boar and stallion spermatozoa following liquid semen storage. Anim Reprod Sci 2022; 247:107076. [PMID: 36166974 DOI: 10.1016/j.anireprosci.2022.107076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/05/2022] [Accepted: 09/21/2022] [Indexed: 11/01/2022]
Abstract
For a more practically applicable analysis of different sperm characteristics, this study aimed to develop a 5-color flow cytometry (FC) panel to concurrently analyze four sperm parameters in liquid boar and stallion semen, using also a DNA-marker for selecting sperm cell events. From each of thirty extended boar semen doses and twelve stallion semen doses, six aliquots were taken. For evaluating mitochondrial activity (A), degree of lipid disorder of plasma membrane (B), integrity of plasma membrane (C), acrosomal status (D) and marking DNA (E), five aliquots were individually stained with Rhodamine 123, Merocyanine 540, Propidium Iodide, PNA-Alexa Fluor 647, and Hoechst 33342, respectively. The sixth aliquot was stained with all the five fluorochromes simultaneously, whereas spectral overlap was corrected by a compensation matrix. Strong correlations were found between the single and 5-color staining assays for boar sperm (A: 0.99, B: 0.96, C: 0.93, D: 0.98, E: 0.99; P < 0.01). Furthermore, moderate and substantial Concordance Correlation Coefficients (CCC) were presented by all these parameters (0.99, 0.96, 0.92, 0.98, and 0.99, respectively). For stallion sperm, the correlation coefficients between the assays were also strong (A: 0.99, B: 0.98, C: 0.99, D: 0.99, E: 0.95; P < 0.01) and substantial CCC were observed for all of them (0.99, 0.97, 0.99, 0.99, and 0.90, respectively). For both species, the mean difference between the methods (d̅) did not overtake 0.84. The results confirmed that this 5-color panel could be successfully implemented for analyzing boar and stallion sperm quality in a single, practical and quick FC assay.
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Affiliation(s)
- Monike Quirino
- Institute for Reproduction of Farm Animals Schönow, Bernau, Germany; Setor de Suínos, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Ulrike Jakop
- Institute for Reproduction of Farm Animals Schönow, Bernau, Germany
| | | | | | - Markus Jung
- Institute for Reproduction of Farm Animals Schönow, Bernau, Germany
| | - Martin Schulze
- Institute for Reproduction of Farm Animals Schönow, Bernau, Germany.
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2
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Schouw HM, Huisman LA, Janssen YF, Slart RHJA, Borra RJH, Willemsen ATM, Brouwers AH, van Dijl JM, Dierckx RA, van Dam GM, Szymanski W, Boersma HH, Kruijff S. Targeted optical fluorescence imaging: a meta-narrative review and future perspectives. Eur J Nucl Med Mol Imaging 2021; 48:4272-4292. [PMID: 34633509 PMCID: PMC8566445 DOI: 10.1007/s00259-021-05504-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 07/23/2021] [Indexed: 12/27/2022]
Abstract
Purpose The aim of this review is to give an overview of the current status of targeted optical fluorescence imaging in the field of oncology, cardiovascular, infectious and inflammatory diseases to further promote clinical translation. Methods A meta-narrative approach was taken to systematically describe the relevant literature. Consecutively, each field was assigned a developmental stage regarding the clinical implementation of optical fluorescence imaging. Results Optical fluorescence imaging is leaning towards clinical implementation in gastrointestinal and head and neck cancers, closely followed by pulmonary, neuro, breast and gynaecological oncology. In cardiovascular and infectious disease, optical imaging is in a less advanced/proof of concept stage. Conclusion Targeted optical fluorescence imaging is rapidly evolving and expanding into the clinic, especially in the field of oncology. However, the imaging modality still has to overcome some major challenges before it can be part of the standard of care in the clinic, such as the provision of pivotal trial data. Intensive multidisciplinary (pre-)clinical joined forces are essential to overcome the delivery of such compelling phase III registration trial data and subsequent regulatory approval and reimbursement hurdles to advance clinical implementation of targeted optical fluorescence imaging as part of standard practice. Supplementary Information The online version contains supplementary material available at 10.1007/s00259-021-05504-y.
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Affiliation(s)
- H M Schouw
- Department of Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - L A Huisman
- Department of Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Y F Janssen
- Department of Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - R H J A Slart
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.,Department of Biomedical Photonic Imaging, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands
| | - R J H Borra
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.,Department of Radiology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - A T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - A H Brouwers
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - J M van Dijl
- Department of Medical Microbiology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - R A Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.,Department of Diagnostic Sciences, Ghent University Faculty of Medicine and Health Sciences, Gent, Belgium
| | - G M van Dam
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.,AxelaRx/TRACER Europe BV, Groningen, The Netherlands
| | - W Szymanski
- Department of Radiology, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - H H Boersma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.,Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Centre of Groningen, Groningen, The Netherlands
| | - S Kruijff
- Department of Surgery, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands. .,Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
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3
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Kim MJ, Cervantes C, Jung YS, Zhang X, Zhang J, Lee SH, Jun S, Litovchick L, Wang W, Chen J, Fang B, Park JI. PAF remodels the DREAM complex to bypass cell quiescence and promote lung tumorigenesis. Mol Cell 2021; 81:1698-1714.e6. [PMID: 33626321 PMCID: PMC8052288 DOI: 10.1016/j.molcel.2021.02.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 12/15/2020] [Accepted: 01/29/2021] [Indexed: 01/01/2023]
Abstract
The DREAM complex orchestrates cell quiescence and the cell cycle. However, how the DREAM complex is deregulated in cancer remains elusive. Here, we report that PAF (PCLAF/KIAA0101) drives cell quiescence exit to promote lung tumorigenesis by remodeling the DREAM complex. PAF is highly expressed in lung adenocarcinoma (LUAD) and is associated with poor prognosis. Importantly, Paf knockout markedly suppressed LUAD development in mouse models. PAF depletion induced LUAD cell quiescence and growth arrest. PAF is required for the global expression of cell-cycle genes controlled by the repressive DREAM complex. Mechanistically, PAF inhibits DREAM complex formation by binding to RBBP4, a core DREAM subunit, leading to transactivation of DREAM target genes. Furthermore, pharmacological mimicking of PAF-depleted transcriptomes inhibited LUAD tumor growth. Our results unveil how the PAF-remodeled DREAM complex bypasses cell quiescence to promote lung tumorigenesis and suggest that the PAF-DREAM axis may be a therapeutic vulnerability in lung cancer.
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Affiliation(s)
- Moon Jong Kim
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Christopher Cervantes
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Youn-Sang Jung
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; Department of Life Science, Chung-Ang University, Seoul 06974, Republic of Korea
| | - Xiaoshan Zhang
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jie Zhang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sung Ho Lee
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Sohee Jun
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Larisa Litovchick
- Department of Internal Medicine and Massey Cancer Center, Virginia Commonwealth University, Richmond, VA 23298, USA
| | - Wenqi Wang
- Department of Developmental and Cell Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Junjie Chen
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Bingliang Fang
- Department of Thoracic and Cardiovascular Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Jae-Il Park
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA; The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA; Program in Genetics and Epigenetics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA.
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4
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Jérôme V, Synatschke CV, Freitag R. Transient Destabilization of Biological Membranes Contributes to the Superior Performance of Star-Shaped PDMAEMA in Delivering pDNA. ACS OMEGA 2020; 5:26640-26654. [PMID: 33110991 PMCID: PMC7581230 DOI: 10.1021/acsomega.0c03367] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 09/17/2020] [Indexed: 06/11/2023]
Abstract
Nonviral DNA vectors are promising alternatives to viral ones. Their use in DNA medicine is limited by an inability to transfect, for example, nondividing or suspension cells. In recent years, star-shaped synthetic polycationic vectors, so called "Nanostars", have shown some promise in this regard, at least when compared to the "gold standard" in nonviral vectors, namely, linear poly(ethyleneimine) (l-PEI). It has been hypothesized that an ability to transiently destabilize cellular membranes is partially responsible for the phenomenon. This hypothesis is investigated here, taking human leukemia suspension cells (Jurkat cells) as an example. Contrary to l-PEI, the Nanostars promote the cellular uptake of small, normally membrane-impermeant molecules (trypan blue and propidium iodide) as well as that of fluorescent polystyrene beads (average diameter 100 nm). Since Nanostars, but not l-PEI, are apparently able to deliver DNA to nuclei of nondividing cells, nuclear uptake is, in addition, investigated with isolated cell nuclei. Our results provide evidence that Nanostars are more efficient than l-PEI in increasing the nuclear membrane association/permeability, allowing accumulation of their cargo on/in the nucleus.
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Affiliation(s)
- Valérie Jérôme
- Process Biotechnology, University of Bayreuth, 95440 Bayreuth, Germany
| | | | - Ruth Freitag
- Process Biotechnology, University of Bayreuth, 95440 Bayreuth, Germany
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5
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Resop RS, Fromentin R, Newman D, Rigsby H, Dubrovsky L, Bukrinsky M, Chomont N, Bosque A. Fingolimod inhibits multiple stages of the HIV-1 life cycle. PLoS Pathog 2020; 16:e1008679. [PMID: 32790802 PMCID: PMC7425850 DOI: 10.1371/journal.ppat.1008679] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 06/03/2020] [Indexed: 02/07/2023] Open
Abstract
Antiretroviral drugs that target various stages of the Human Immunodeficiency Virus (HIV) life cycle have been effective in curbing the AIDS epidemic. However, drug resistance, off-target effects of antiretroviral therapy (ART), and varying efficacy in prevention underscore the need to develop novel and alternative therapeutics. In this study, we investigated whether targeting the signaling molecule Sphingosine-1-phosphate (S1P) would inhibit HIV-1 infection and generation of the latent reservoir in primary CD4 T cells. We show that FTY720 (Fingolimod), an FDA-approved functional antagonist of S1P receptors, blocks cell-free and cell-to-cell transmission of HIV and consequently reduces detectable latent virus. Mechanistically, FTY720 impacts the HIV-1 life cycle at two levels. Firstly, FTY720 reduces the surface density of CD4, thereby inhibiting viral binding and fusion. Secondly, FTY720 decreases the phosphorylation of the innate HIV restriction factor SAMHD1 which is associated with reduced levels of total and integrated HIV, while reducing the expression of Cyclin D3. In conclusion, targeting the S1P pathway with FTY720 could be a novel strategy to inhibit HIV replication and reduce the seeding of the latent reservoir.
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Affiliation(s)
- Rachel S. Resop
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
| | - Rémi Fromentin
- Centre de recherche du CHUM and Department of microbiology, infectiology and immunology, Université de Montréal, Montreal, Canada
| | - Daniel Newman
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
| | - Hawley Rigsby
- Centre de recherche du CHUM and Department of microbiology, infectiology and immunology, Université de Montréal, Montreal, Canada
| | - Larisa Dubrovsky
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
| | - Michael Bukrinsky
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
| | - Nicolas Chomont
- Centre de recherche du CHUM and Department of microbiology, infectiology and immunology, Université de Montréal, Montreal, Canada
| | - Alberto Bosque
- Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, D.C., United States of America
- * E-mail:
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6
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Inducing controlled cell cycle arrest and re-entry during asexual proliferation of Plasmodium falciparum malaria parasites. Sci Rep 2018; 8:16581. [PMID: 30409996 PMCID: PMC6224408 DOI: 10.1038/s41598-018-34964-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 10/26/2018] [Indexed: 02/08/2023] Open
Abstract
The life cycle of the malaria parasite Plasmodium falciparum is tightly regulated, oscillating between stages of intense proliferation and quiescence. Cyclic 48-hour asexual replication of Plasmodium is markedly different from cell division in higher eukaryotes, and mechanistically poorly understood. Here, we report tight synchronisation of malaria parasites during the early phases of the cell cycle by exposure to DL-α-difluoromethylornithine (DFMO), which results in the depletion of polyamines. This induces an inescapable cell cycle arrest in G1 (~15 hours post-invasion) by blocking G1/S transition. Cell cycle-arrested parasites enter a quiescent G0-like state but, upon addition of exogenous polyamines, re-initiate their cell cycle. This ability to halt malaria parasites at a specific point in their cell cycle, and to subsequently trigger re-entry into the cell cycle, provides a valuable framework to investigate cell cycle regulation in these parasites. We subsequently used gene expression analyses to show that re-entry into the cell cycle involves expression of Ca2+-sensitive (cdpk4 and pk2) and mitotic kinases (nima and ark2), with deregulation of the pre-replicative complex associated with expression of pk2. Changes in gene expression could be driven through transcription factors MYB1 and two ApiAP2 family members. This new approach to parasite synchronisation therefore expands our currently limited toolkit to investigate cell cycle regulation in malaria parasites.
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7
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The prolyl oligopeptidase inhibitor SUAM-14746 attenuates the proliferation of human breast cancer cell lines in vitro. Breast Cancer 2017; 24:658-666. [DOI: 10.1007/s12282-017-0752-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 01/03/2017] [Indexed: 02/06/2023]
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8
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Chan CN, Trinité B, Lee CS, Mahajan S, Anand A, Wodarz D, Sabbaj S, Bansal A, Goepfert PA, Levy DN. HIV-1 latency and virus production from unintegrated genomes following direct infection of resting CD4 T cells. Retrovirology 2016; 13:1. [PMID: 26728316 PMCID: PMC4700562 DOI: 10.1186/s12977-015-0234-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Accepted: 12/21/2015] [Indexed: 12/31/2022] Open
Abstract
Background HIV-1 integration is prone to a high rate of failure, resulting in the accumulation of unintegrated viral genomes (uDNA) in vivo and in vitro. uDNA can be transcriptionally active, and circularized uDNA genomes are biochemically stable in non-proliferating cells. Resting, non-proliferating CD4 T cells are prime targets of HIV-1 infection and latently infected resting CD4 T cells are the major barrier to HIV cure. Our prior studies demonstrated that uDNA generates infectious virions when T cell activation follows rather than precedes infection. Results Here, we characterize in primary resting CD4 T cells the dynamics of integrated and unintegrated virus expression, genome persistence and sensitivity to latency reversing agents. Unintegrated HIV-1 was abundant in directly infected resting CD4 T cells. Maximal gene expression from uDNA was delayed compared with integrated HIV-1 and was less toxic, resulting in uDNA enrichment over time relative to integrated proviruses. Inhibiting integration with raltegravir shunted the generation of durable latency from integrated to unintegrated genomes. Latent uDNA was activated to de novo virus production by latency reversing agents that also activated latent integrated proviruses, including PKC activators, histone deacetylase inhibitors and P-TEFb agonists. However, uDNA responses displayed a wider dynamic range, indicating differential regulation of expression relative to integrated proviruses. Similar to what has recently been demonstrated for latent integrated proviruses, one or two applications of latency reversing agents failed to activate all latent unintegrated genomes. Unlike integrated proviruses, uDNA gene expression did not down modulate expression of HLA Class I on resting CD4 T cells. uDNA did, however, efficiently prime infected cells for killing by HIV-1-specific cytotoxic T cells. Conclusions These studies demonstrate that contributions by unintegrated genomes to HIV-1 gene expression, virus production, latency and immune responses are inherent properties of the direct infection of resting CD4 T cells. Experimental models of HIV-1 latency employing directly infected resting CD4 T cells should calibrate the contribution of unintegrated HIV-1. Electronic supplementary material The online version of this article (doi:10.1186/s12977-015-0234-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Chi N Chan
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
| | - Benjamin Trinité
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
| | - Caroline S Lee
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
| | - Saurabh Mahajan
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
| | - Akanksha Anand
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
| | - Dominik Wodarz
- Department of Ecology and Evolutionary Biology, University of California, Irvine, School of Biological, Sciences, Irvine, CA, 92697, USA.
| | - Steffanie Sabbaj
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Anju Bansal
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - Paul A Goepfert
- Department of Medicine, University of Alabama at Birmingham, Birmingham, AL, 35294, USA.
| | - David N Levy
- Department of Basic Science, New York University College of Dentistry, New York, NY, 10010, USA.
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9
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HIV-1 Vpr- and Reverse Transcription-Induced Apoptosis in Resting Peripheral Blood CD4 T Cells and Protection by Common Gamma-Chain Cytokines. J Virol 2015; 90:904-16. [PMID: 26537673 DOI: 10.1128/jvi.01770-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/26/2015] [Indexed: 02/07/2023] Open
Abstract
UNLABELLED HIV-1 infection leads to the progressive depletion of the CD4 T cell compartment by various known and unknown mechanisms. In vivo, HIV-1 infects both activated and resting CD4 T cells, but in vitro, in the absence of any stimuli, resting CD4 T cells from peripheral blood are resistant to infection. This resistance is generally attributed to an intracellular environment that does not efficiently support processes such as reverse transcription (RT), resulting in abortive infection. Here, we show that in vitro HIV-1 infection of resting CD4 T cells induces substantial cell death, leading to abortive infection. In vivo, however, various microenvironmental stimuli in lymphoid and mucosal tissues provide support for HIV-1 replication. For example, common gamma-chain cytokines (CGCC), such as interleukin-7 (IL-7), render resting CD4 T cells permissible to HIV-1 infection without inducing T cell activation. Here, we find that CGCC primarily allow productive infection by preventing HIV-1 triggering of apoptosis, as evidenced by early release of cytochrome c and caspase 3/7 activation. Cell death is triggered both by products of reverse transcription and by virion-borne Vpr protein, and CGCC block both mechanisms. When HIV-1 RT efficiency was enhanced by SIVmac239 Vpx protein, cell death was still observed, indicating that the speed of reverse transcription and the efficiency of its completion contributed little to HIV-1-induced cell death in this system. These results show that a major restriction on HIV-1 infection in resting CD4 T cells resides in the capacity of these cells to survive the early steps of HIV-1 infection. IMPORTANCE A major consequence of HIV-1 infection is the destruction of CD4 T cells. Here, we show that delivery of virion-associated Vpr protein and the process of reverse transcription are each sufficient to trigger apoptosis of resting CD4 T cells isolated from peripheral blood. While these 2 mechanisms have been previously described in various cell types, we show for the first time their concerted effect in inducing resting CD4 T cell depletion. Importantly, we found that cytokines such as IL-7 and IL-4, which are particularly active in sites of HIV-1 replication, protect resting CD4 T cells from these cytopathic effects and, primarily through this protection, rather than through enhancement of specific replicative steps, they promote productive infection. This study provides important new insights for the understanding of the early steps of HIV-1 infection and T cell depletion.
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10
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López-Ruano G, Prieto-Bermejo R, Ramos TL, San-Segundo L, Sánchez-Abarca LI, Sánchez-Guijo F, Pérez-Simón JA, Sánchez-Yagüe J, Llanillo M, Hernández-Hernández Á. PTPN13 and β-Catenin Regulate the Quiescence of Hematopoietic Stem Cells and Their Interaction with the Bone Marrow Niche. Stem Cell Reports 2015; 5:516-31. [PMID: 26344907 PMCID: PMC4624939 DOI: 10.1016/j.stemcr.2015.08.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 08/04/2015] [Accepted: 08/05/2015] [Indexed: 12/29/2022] Open
Abstract
The regulation of hematopoietic stem cells (HSCs) depends on the integration of the multiple signals received from the bone marrow niche. We show the relevance of the protein tyrosine phosphatase PTPN13 and β-catenin as intracellular signaling molecules to control HSCs adhesiveness, cell cycling, and quiescence. Lethally irradiated mice transplanted with Lin– bone marrow cells in which PTPN13 or β-catenin had been silenced showed a significant increase of long-term (LT) and short-term (ST) HSCs. A decrease in cycling cells was also found, together with an increase in quiescence. The decreased expression of PTPN13 or β-catenin was linked to the upregulation of several genes coding for integrins and several cadherins, explaining the higher cell adhesiveness. Our data are consistent with the notion that the levels of PTPN13 and β-catenin must be strictly regulated by extracellular signaling to regulate HSC attachment to the niche and the balance between proliferation and quiescence. PTPN13 or β-catenin silencing increases LT-HSCs and ST-HSCs frequency in vivo The cell cycling of HSPCs was decreased by PTPN13 or β-catenin downregulation LT-HSCs and ST-HSCs quiescence was increased by PTPN13 or β-catenin downregulation PTPN13 and β-catenin levels modulate the interaction of HSPCs with the BM niche
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Affiliation(s)
- Guillermo López-Ruano
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca 37007, Spain; IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Rodrigo Prieto-Bermejo
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca 37007, Spain; IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Teresa L Ramos
- IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Laura San-Segundo
- IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Luis Ignacio Sánchez-Abarca
- Department of Hematology, Hospital Universitario Virgen del Rocío/IBIS/CSIC/University of Seville, Seville 41013, Spain
| | - Fermín Sánchez-Guijo
- IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - José Antonio Pérez-Simón
- Department of Hematology, Hospital Universitario Virgen del Rocío/IBIS/CSIC/University of Seville, Seville 41013, Spain
| | - Jesús Sánchez-Yagüe
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca 37007, Spain; IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Marcial Llanillo
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca 37007, Spain; IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain
| | - Ángel Hernández-Hernández
- Department of Biochemistry and Molecular Biology, University of Salamanca, Salamanca 37007, Spain; IBSAL (Instituto de Investigación Biomédica de Salamanca), Salamanca 37007, Spain.
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11
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Taylor HE, Simmons GE, Mathews TP, Khatua AK, Popik W, Lindsley CW, D’Aquila RT, Brown HA. Phospholipase D1 Couples CD4+ T Cell Activation to c-Myc-Dependent Deoxyribonucleotide Pool Expansion and HIV-1 Replication. PLoS Pathog 2015; 11:e1004864. [PMID: 26020637 PMCID: PMC4447393 DOI: 10.1371/journal.ppat.1004864] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 04/07/2015] [Indexed: 12/25/2022] Open
Abstract
Quiescent CD4+ T cells restrict human immunodeficiency virus type 1 (HIV-1) infection at early steps of virus replication. Low levels of both deoxyribonucleotide triphosphates (dNTPs) and the biosynthetic enzymes required for their de novo synthesis provide one barrier to infection. CD4+ T cell activation induces metabolic reprogramming that reverses this block and facilitates HIV-1 replication. Here, we show that phospholipase D1 (PLD1) links T cell activation signals to increased HIV-1 permissivity by triggering a c-Myc-dependent transcriptional program that coordinates glucose uptake and nucleotide biosynthesis. Decreasing PLD1 activity pharmacologically or by RNA interference diminished c-Myc-dependent expression during T cell activation at the RNA and protein levels. PLD1 inhibition of HIV-1 infection was partially rescued by adding exogenous deoxyribonucleosides that bypass the need for de novo dNTP synthesis. Moreover, the data indicate that low dNTP levels that impact HIV-1 restriction involve decreased synthesis, and not only increased catabolism of these nucleotides. These findings uncover a unique mechanism of action for PLD1 inhibitors and support their further development as part of a therapeutic combination for HIV-1 and other viral infections dependent on host nucleotide biosynthesis.
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Affiliation(s)
- Harry E. Taylor
- Northwestern HIV Translational Research Center, Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
- * E-mail: (HET); (HAB)
| | - Glenn E. Simmons
- Department of Molecular Genetics, University of Texas, Southwestern Medical Center, Dallas, Texas, United States of America
| | - Thomas P. Mathews
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Atanu K. Khatua
- Meharry Medical College, Center for AIDS Health Disparities Research, Nashville, Tennessee, United States of America
| | - Waldemar Popik
- Meharry Medical College, Center for AIDS Health Disparities Research, Nashville, Tennessee, United States of America
| | - Craig W. Lindsley
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Center for Neuroscience Drug Discovery, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Chemistry, Vanderbilt University, Nashville, Tennesee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Richard T. D’Aquila
- Northwestern HIV Translational Research Center, Division of Infectious Diseases, Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, United States of America
| | - H. Alex Brown
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
- * E-mail: (HET); (HAB)
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Kant Upadhyay R. Biomarkers in Japanese encephalitis: a review. BIOMED RESEARCH INTERNATIONAL 2013; 2013:591290. [PMID: 24455705 PMCID: PMC3878288 DOI: 10.1155/2013/591290] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/24/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 12/11/2022]
Abstract
JE is a flavivirus generated dreadful CNS disease which causes high mortality in various pediatric groups. JE disease is currently diagnosed by measuring the level of viral antigens and virus neutralization IgM antibodies in blood serum and CSF by ELISA. However, it is not possible to measure various disease-identifying molecules, structural and molecular changes occurred in tissues, and cells by using such routine methods. However, few important biomarkers such as cerebrospinal fluid, plasma, neuro-imaging, brain mapping, immunotyping, expression of nonstructural viral proteins, systematic mRNA profiling, DNA and protein microarrays, active caspase-3 activity, reactive oxygen species and reactive nitrogen species, levels of stress-associated signaling molecules, and proinflammatory cytokines could be used to confirm the disease at an earlier stage. These biomarkers may also help to diagnose mutant based environment specific alterations in JEV genotypes causing high pathogenesis and have immense future applications in diagnostics. There is an utmost need for the development of new more authentic, appropriate, and reliable physiological, immunological, biochemical, biophysical, molecular, and therapeutic biomarkers to confirm the disease well in time to start the clinical aid to the patients. Hence, the present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of JE disease and its related disorders in the future.
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Affiliation(s)
- Ravi Kant Upadhyay
- Department of Zoology, D. D. U. Gorakhpur University, Gorakhpur, Uttar Pradesh 273009, India
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13
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Endothelial cell stimulation overcomes restriction and promotes productive and latent HIV-1 infection of resting CD4+ T cells. J Virol 2013; 87:9768-79. [PMID: 23824795 DOI: 10.1128/jvi.01478-13] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Highly active antiretroviral therapy (HAART) is able to suppress human immunodeficiency virus type 1 (HIV-1) to undetectable levels in the majority of patients, but eradication has not been achieved because latent viral reservoirs persist, particularly in resting CD4(+) T lymphocytes. It is generally understood that HIV-1 does not efficiently infect resting CD4(+) T cells, and latent infection in those cells may arise when infected CD4(+) T lymphoblasts return to resting state. In this study, we found that stimulation by endothelial cells can render resting CD4(+) T cells permissible for direct HIV infection, including both productive and latent infection. These stimulated T cells remain largely phenotypically unactivated and show a lower death rate than activated T cells, which promotes the survival of infected cells. The stimulation by endothelial cells does not involve interleukin 7 (IL-7), IL-15, CCL19, or CCL21. Endothelial cells line the lymphatic vessels in the lymphoid tissues and have frequent interactions with T cells in vivo. Our study proposes a new mechanism for infection of resting CD4(+) T cells in vivo and a new mechanism for latent infection in resting CD4(+) T cells.
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Pallis M, Burrows F, Whittall A, Boddy N, Seedhouse C, Russell N. Efficacy of RNA polymerase II inhibitors in targeting dormant leukaemia cells. BMC Pharmacol Toxicol 2013; 14:32. [PMID: 23767415 PMCID: PMC3685571 DOI: 10.1186/2050-6511-14-32] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 06/05/2013] [Indexed: 11/16/2022] Open
Abstract
Background Dormant cells are characterised by low RNA synthesis. In contrast, cancer cells can be addicted to high RNA synthesis, including synthesis of survival molecules. We hypothesised that dormant cancer cells, already low in RNA, might be sensitive to apoptosis induced by RNA Polymerase II (RP2) inhibitors that further reduce RNA synthesis. Methods We cultured leukaemia cells continuously in vitro in the presence of an mTOR inhibitor to model dormancy. Apoptosis, damage, RNA content and reducing capacity were evaluated. We treated dormancy-enriched cells for 48 hours with the nucleoside analogues ara-C, 5-azacytidine and clofarabine, the topoisomerase targeting agents daunorubicin, etoposide and irinotecan and three multikinase inhibitors with activity against RP2 - flavopiridol, roscovitine and TG02, and we measured growth inhibition and apoptosis. We describe use of the parameter 2 × IC50 to measure residual cell targeting. RNA synthesis was measured with 5-ethynyl uridine. Drug-induced apoptosis was measured flow cytometrically in primary cells from patients with acute myeloid leukaemia using a CD34/CD71/annexinV gating strategy to identify dormant apoptotic cells. Results Culture of the KG1a cell line continuously in the presence of an mTOR inhibitor induced features of dormancy including low RNA content, low metabolism and low basal ROS formation in the absence of a DNA damage response or apoptosis. All agents were more effective against the unmanipulated than the dormancy-enriched cells, emphasising the chemoresistant nature of dormant cells. However, the percentage of cell reduction by RP2 inhibitors at 2 × IC50 was significantly greater than that of other agents. RP2 inhibitors strongly inhibited RNA synthesis compared with other drugs. We also showed that RP2 inhibitors induce apoptosis in proliferating and dormancy-enriched KG1a cells and in the CD71neg CD34pos subset of primary acute myeloid leukaemia cells. Conclusion We suggest that RP2 inhibitors may be a useful class of agent for targeting dormant leukaemia cells.
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Bosque A, Famiglietti M, Weyrich AS, Goulston C, Planelles V. Homeostatic proliferation fails to efficiently reactivate HIV-1 latently infected central memory CD4+ T cells. PLoS Pathog 2011; 7:e1002288. [PMID: 21998586 PMCID: PMC3188522 DOI: 10.1371/journal.ppat.1002288] [Citation(s) in RCA: 161] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2011] [Accepted: 08/12/2011] [Indexed: 11/18/2022] Open
Abstract
Homeostatic proliferation ensures the longevity of central memory T-cells by inducing cell proliferation in the absence of cellular differentiation or activation. This process is governed mainly by IL-7. Central memory T-cells can also be stimulated via engagement of the T-cell receptor, leading to cell proliferation but also activation and differentiation. Using an in vitro model of HIV-1 latency, we have examined in detail the effects of homeostatic proliferation on latently infected central memory T cells. We have also used antigenic stimulation via anti-CD3/anti-CD28 antibodies and established a comparison with a homeostatic proliferation stimulus, to evaluate potential differences in how either treatment affects the dynamics of latent virus populations. First, we show that homeostatic proliferation, as induced by a combination of IL-2 plus IL-7, leads to partial reactivation of latent HIV-1 but is unable to reduce the size of the reservoir in vitro. Second, latently infected cells are able to homeostatically proliferate in the absence of viral reactivation or cell differentiation. These results indicate that IL-2 plus IL-7 may induce a detrimental effect by favoring the maintenance of the latent HIV-1 reservoir. On the other hand, antigenic stimulation efficiently reactivated latent HIV-1 in cultured central memory cells and led to depletion of the latently infected cells via virus-induced cell death. HIV-1 latently infected cells are considered the last barrier towards viral eradication and cure. However, the low number of latently infected cells found in patients makes studies extremely difficult. Here, using a model of primary CD4 T-cells we study the behavior of latently infected central memory T cells when undergoing homeostatic proliferation. Homeostatic proliferation ensures the longevity of the central memory population, as it does not involve cellular differentiation. In the context of HIV infection, IL-7 has been reported to induce viral outgrowth from latently infected cells in different cellular models. However, those studies did not examine the relationship between cell proliferation and viral reactivation. We here report that the strong effect of IL-7 on the proliferation of memory cells counteracts this cytokine's modest ability to purge latent viruses. Thus, central memory cells are subject to homeostatic proliferation, a physiological effect that may contribute to the longevity of the latent reservoir in HIV-1 infected patients.
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Affiliation(s)
- Alberto Bosque
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
| | - Marylinda Famiglietti
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
- International PhD School in Molecular Medicine, Basic and Applied Immunology Section, Vita-Salute San Raffaele University, Milano, Italy
| | - Andrew S. Weyrich
- Program in Human Molecular Biology and Genetics, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, Utah, United States of America
| | - Claudia Goulston
- Division of Infectious Diseases, Department of Medicine, University of Utah, Salt Lake City, Utah, United States of America
| | - Vicente Planelles
- Department of Pathology, University of Utah, Salt Lake City, Utah, United States of America
- * E-mail:
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16
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Oncogenic Kras initiates leukemia in hematopoietic stem cells. PLoS Biol 2009; 7:e59. [PMID: 19296721 PMCID: PMC2656550 DOI: 10.1371/journal.pbio.1000059] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2008] [Accepted: 01/30/2009] [Indexed: 02/07/2023] Open
Abstract
How oncogenes modulate the self-renewal properties of cancer-initiating cells is incompletely understood. Activating KRAS and NRAS mutations are among the most common oncogenic lesions detected in human cancer, and occur in myeloproliferative disorders (MPDs) and leukemias. We investigated the effects of expressing oncogenic KrasG12D from its endogenous locus on the proliferation and tumor-initiating properties of murine hematopoietic stem and progenitor cells. MPD could be initiated by KrasG12D expression in a highly restricted population enriched for hematopoietic stem cells (HSCs), but not in common myeloid progenitors. KrasG12D HSCs demonstrated a marked in vivo competitive advantage over wild-type cells. KrasG12D expression also increased the fraction of proliferating HSCs and reduced the overall size of this compartment. Transplanted KrasG12D HSCs efficiently initiated acute T-lineage leukemia/lymphoma, which was associated with secondary Notch1 mutations in thymocytes. We conclude that MPD-initiating activity is restricted to the HSC compartment in KrasG12D mice, and that distinct self-renewing populations with cooperating mutations emerge during cancer progression. Ras proteins act as molecular switches that relay growth signals from outside the cell. This mechanism is often subverted in cancer, and Ras proteins are activated directly by RAS gene mutations in approximately one-third of human malignancies. We have modeled this in mice engineered to have a Ras mutation. These mice develop a disease similar to chronic leukemias in humans called myeloproliferative disorders. It is marked by a fatal accumulation of mature and immature cells in the blood and bone marrow. We investigated whether some or all of these neoplastic cells were immortal. In agreement with the “cancer stem cell” hypothesis, we found that immortal cells were extremely rare in the bone marrow of diseased mice. They were found only in the same cell populations that contain normal bone marrow stem cells. However, these cells had high rates of replication and produced large numbers of daughter cells. Furthermore, many mice went on to develop acute lymphoid leukemia after acquiring additional mutations in maturing lymphoid cells. These studies exemplify the evolution of malignant stem cells during cancer progression. They also highlight the importance of rare, long-lived cells in the genesis and, potentially, therapy of high-risk chronic leukemias caused by abnormal Ras proteins. TheKrasG12D oncogene causes excessive proliferation of stem cells, promoting their preferential expansion and initiating myeloproliferative disease.KrasG12D does not alter self-renewal, but secondary mutations in lymphoid progenitors allow progression to acute leukemia.
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Behbod F, Xian W, Shaw CA, Hilsenbeck SG, Tsimelzon A, Rosen JM. Transcriptional Profiling of Mammary Gland Side Population Cells. Stem Cells 2009; 24:1065-74. [PMID: 16282442 DOI: 10.1634/stemcells.2005-0375] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Similar to the bone marrow, the mammary gland contains a distinct population of Hoechst-effluxing side population cells, mammary gland side population cells (MG-SPs). To better characterize MG-SPs, their microarray gene profiles were compared to the remaining cells, which retain Hoechst dye (mammary gland non-side population cells [MG-NSPs]). For analysis, Gene Ontology (GO) that describes genes in terms of biological processes and Ontology Traverser (OT) that performs enrichment analysis were used. OT showed that MG-SP-specific genes were enriched in the GO categories of cell cycle regulation and checkpoints, multidrug-resistant transporters, organogenesis, and vasculogenesis. The MG-NSP-upregulated genes were enriched in the GO category of cellular organization and biogenesis, which includes basal epithelial markers, p63, smooth muscle actin, myosin, alpha6 integrin, cytokeratin (CK) 14, and luminal markers CK8 and CD24. Additional studies showed that a higher percentage of MG-SPs exist in the G1 phase of the cell cycle compared with the MG-NSPs. G1 cell cycle block of MG-SPs may be explained by higher expression of cell cycle-negative regulatory genes such as transforming growth factor-beta2, insulin-like growth factor binding protein-5, P18(INK4C), and wingless-5a (Wnt-5a). Accordingly, a smaller percentage of MG-SPs expressed nuclear beta-catenin, possibly as a consequence of the higher expression of Wnt-5a. In conclusion, microarray gene profiling suggests that MG-SPs are a lineage-deficient mammary gland subpopulation expressing key genes involved in cell cycle regulation, development, and angiogenesis.
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Affiliation(s)
- Fariba Behbod
- Department of Molecular and Cellular Biology, DeBakey Building, M638a, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030-3498, USA
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18
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Watanabe C, Shu GL, Zheng TS, Flavell RA, Clark EA. Caspase 6 regulates B cell activation and differentiation into plasma cells. THE JOURNAL OF IMMUNOLOGY 2008; 181:6810-9. [PMID: 18981099 DOI: 10.4049/jimmunol.181.10.6810] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Caspase (Casp) family proteases regulate not only lymphocyte apoptosis but also lymphocyte activation and development. In this study, we show that Casp6 regulates B cell activation and differentiation into plasma cells by modifying cell cycle entry. B cells from Casp6 knockout (Casp6 KO) mice examined ex vivo have more cells in G(1) than wild-type B cells, and mitogen-induced G(1) entry of Casp6 KO B cells is much faster than that of wild-type B cells. Even so, S phase entry and proliferation are not increased in Casp6 KO B cells. Rather than proliferating, activated Casp6 KO B cells preferentially differentiate into syndecan-1(+) plasma cells and produce Abs. In Casp6 KO mice compared with WT mice, serum levels of IgG1, IgG2a, and IgG2b are increased and Ag-specific Ab responses are also enhanced along with increased percentages of syndecan-1(+) plasma cells. Casp6 may regulate both B cell activation and differentiation by modifying requirements for G(0) B cells to enter G(1).
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Affiliation(s)
- Chie Watanabe
- Department of Immunology, University of Washington, Seattle, WA 98195, USA
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Richards S, Watanabe C, Santos L, Craxton A, Clark EA. Regulation of B-cell entry into the cell cycle. Immunol Rev 2008; 224:183-200. [PMID: 18759927 DOI: 10.1111/j.1600-065x.2008.00652.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
B cells are induced to enter the cell cycle by stimuli including ligation of the B-cell receptor (BCR) complex and Toll-like receptor (TLR) agonists. This review discusses the contribution of several molecules, which act at distinct steps in B-cell activation. The adapter molecule Bam32 (B-lymphocyte adapter of 32 kDa) helps promote BCR-induced cell cycle entry, while the secondary messenger superoxide has the opposite effect. Bam32 and superoxide may fine tune BCR-induced activation by competing for the same limited resources, namely Rac1 and the plasma membrane phospholipid PI(3,4)P(2). The co-receptor CD22 can inhibit BCR-induced proliferation by binding to novel CD22 ligands. Finally, regulators of B-cell survival and death also play roles in B-cell transit through the cell cycle. Caspase 6 negatively regulates CD40- and TLR-dependent G(1) entry, while acting later in the cell cycle to promote S-phase entry. Caspase 6 deficiency predisposes B cells to differentiate rather than proliferate after stimulation. Bim, a pro-apoptotic Bcl-2 family member, exerts a positive regulatory effect on cell cycle entry, which is opposed by Bcl-2. New insights into what regulates B-cell transit through the cell cycle may lead to thoughtful design of highly selective drugs that target pathogenic B cells.
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Affiliation(s)
- Sabrina Richards
- Department of Immunology and Microbiology, University of Washington, Seattle, WA 98195, USA
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20
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Das S, Basu A. Japanese encephalitis virus infects neural progenitor cells and decreases their proliferation. J Neurochem 2008; 106:1624-36. [PMID: 18540995 DOI: 10.1111/j.1471-4159.2008.05511.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Japanese encephalitis virus (JEV), a common cause of encephalitis in humans, especially in children, leads to substantial neuronal injury. The survivors of JEV infection have severe cognitive impairment, motor and behavioral disorders. We hypothesize that depletion of neural progenitor cells (NPCs) by the virus culminates in neurological sequelae in survivors of Japanese encephalitis (JE). We utilized both in vivo model of JEV infection and in vitro neurosphere cultures to study progressive JEV infection. Cellular infection and cell death was determined by flow cytometry. BrdU administration in animals and in neurospheres was used to determine the proliferative ability of NPCs. JEV leads to massive loss of actively proliferating NPC population from the subventricular zone (SVZ). The ability of JEV infected subventricular zone cells to form neurospheres is severely compromised. This can be attributed to JEV infection in NPCs, which however do not result in robust death of the resilient NPC cells. Instead, JEV suppresses the cycling ability of these cells, preventing their proliferation. JEV primarily targets at a critical postnatal age and severely diminishes the NPC pool in SVZ, thus impairing the process of recovery after the insult. This arrested growth and proliferation of NPCs might have an effect on the neurological consequences in JE survivors.
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Affiliation(s)
- Sulagna Das
- National Brain Research Centre, Manesar, Haryana, India
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21
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Sitton G, Srienc F. Growth dynamics of mammalian cells monitored with automated cell cycle staining and flow cytometry. Cytometry A 2008; 73:538-45. [DOI: 10.1002/cyto.a.20567] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Meyer-Bahlburg A, Andrews SF, Yu KOA, Porcelli SA, Rawlings DJ. Characterization of a late transitional B cell population highly sensitive to BAFF-mediated homeostatic proliferation. ACTA ACUST UNITED AC 2008; 205:155-68. [PMID: 18180309 PMCID: PMC2234381 DOI: 10.1084/jem.20071088] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We have characterized a distinct, late transitional B cell subset, CD21int transitional 2 (T2) B cells. In contrast to early transitional B cells, CD21int T2 B cells exhibit augmented responses to a range of potential microenvironmental stimuli. Adoptive transfer studies demonstrate that this subset is an immediate precursor of both follicular mature and marginal zone (MZ) B cells. In vivo, a large percentage of CD21int T2 B cells has entered the cell cycle, and the cycling subpopulation exhibits further augmentation in mitogenic responses and B cell-activating factor of the TNF family (BAFF) receptor expression. Consistent with these features, CD21int T2 cells exhibit preferential responses to BAFF-facilitated homeostatic signals in vivo. In addition, we demonstrate that M167 B cell receptor (BCR) idiotypic-specific B cells are first selected within the cycling CD21int T2 population, ultimately leading to preferential enrichment of these cells within the MZ B cell compartment. These data, in association with the coordinate role for BAFF and microenvironmental cues in determining the mature BCR repertoire, imply that this subset functions as a unique selection point in peripheral B cell development.
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Affiliation(s)
- Almut Meyer-Bahlburg
- Department of Pediatrics, University of Washington School of Medicine, Seattle, WA 98195, USA
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Erickson RI, Paucar AA, Jackson RL, Visnyei K, Kornblum H. Roles of insulin and transferrin in neural progenitor survival and proliferation. J Neurosci Res 2008; 86:1884-94. [DOI: 10.1002/jnr.21631] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Schmid I. Combined Flow Cytometric Measurement of Two Cell-Surface Antigens and DNA-RNA Content. Cold Spring Harb Protoc 2007; 2007:pdb.prot4895. [PMID: 21356985 DOI: 10.1101/pdb.prot4895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
INTRODUCTIONFlow cytometry is frequently used to assess nucleic acid content in individual cells. Based on DNA content alone, however, cells in the quiescent G(0) phase cannot be discriminated from cells in the proliferative G(1) phase, as DNA content remains constant until S-phase entry. In contrast, by measuring RNA content in addition to DNA content, cells can be assigned to G(0) and cell-cycle subcompartments of G(1). Assessing phenotype at the same time as nucleic acid content allows determination of the cell-cycle status of subpopulations in mixed-cell preparations. This protocol describes an optimized method for combining dual-color cell-surface immunofluorescent staining with staining for DNA-RNA, adapted for a basic dual-laser flow cytometer with blue (488-nm) and red (633- or 647-nm) excitation. DNA is stained at low pH in the presence of saponin with 7-aminoactinomycin D (7-AAD), and RNA is stained with pyronin Y (PY). Both dyes are used at low concentration, and 7-AAD is exchanged with nonfluorescent actinomycin D to minimize fluorochrome-fluorochrome interactions, which can negatively affect detection of cell-surface antigen staining.
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Affiliation(s)
- Ingrid Schmid
- David Geffen School of Medicine at UCLA, Department of Hematology/Oncology, Los Angeles, CA 90095, USA
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25
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Campi-Azevedo AC, Gazzinelli G, Bottazzi ME, Teixeira-Carvalho A, Corrêa-Oliveira R, Caldas IR. In vitro cultured peripheral blood mononuclear cells from patients with chronic schistosomiasis mansoni show immunomodulation of cyclin D1,2,3 in the presence of soluble egg antigens. Microbes Infect 2007; 9:1493-9. [PMID: 17913547 DOI: 10.1016/j.micinf.2007.08.004] [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: 05/29/2007] [Revised: 07/25/2007] [Accepted: 08/05/2007] [Indexed: 11/18/2022]
Abstract
Infection with Schistosoma mansoni induces a wide range of effects on the immune responses of the host. In the present study we investigated the influence of soluble egg antigens (SEA) on the cell cycle of peripheral blood mononuclear cells (PBMC) from infected and non-infected individuals with S. mansoni resident in an endemic area and blood donors from non-endemic area. The cell cycle, the expression of activation markers and cyclin D(+)(1,2,3) CD3(+) frequency was assessed by flow cytometry. Stimulation of PBMC from infected patients with SEA resulted in a lower frequency of CD3(+) T cells in S phase when compared with the non-infected group. In addition, infected patients presented a decrease of activation marker expression (CD69(+), HLA-DR(+) and CD28(-) on CD4(+) cells and CD25(+), HLA-DR(+) on CD8(+) cells). A reduced frequency was observed of cyclin D(1,2,3) expression in SEA-stimulated T cells from infected individuals when compared with those from the non-infected group. The decreased expression of activation markers and frequency of cyclin D(1,2,3) in T cells may result in arrest of T cells in the G(0)/G(1) phase of the cell cycle, thus explaining the down-regulation observed in chronic schistosomiasis.
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Affiliation(s)
- Ana Carolina Campi-Azevedo
- Laboratório de Imunologia Celular e Molecular, Instituto René Rachou/FIOCRUZ, Fundação Oswaldo Cruz, Avenida Augusto de Lima 1715, Barro Preto, 30190-002 Belo Horizonte, MG, Brazil
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Chen MS, Woodward WA, Behbod F, Peddibhotla S, Alfaro MP, Buchholz TA, Rosen JM. Wnt/beta-catenin mediates radiation resistance of Sca1+ progenitors in an immortalized mammary gland cell line. J Cell Sci 2007; 120:468-77. [PMID: 17227796 DOI: 10.1242/jcs.03348] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The COMMA-Dbeta-geo cell line has been shown to contain a permanent subpopulation of progenitor cells that are enriched in outgrowth potential. Using the COMMA-Dbeta-geo cell line as a model, we sought to study the radioresistance of mammary progenitor cells. Using the putative progenitor cell marker stem cell antigen 1 (Sca1), we were able to isolate a discrete subpopulation of Sca1(+) multipotent cells from the immortalized COMMA-Dbeta-geo murine mammary cell line. At a clinically relevant dose, the Sca1(+) cells were resistant to radiation (2 Gy). Sca1(+) cells contained fewer gamma-H2AX(+) DNA damage foci following irradiation, displayed higher levels of endogenous beta-catenin, and selectively upregulated survivin after radiation. Expression of active beta-catenin enhanced self-renewal preferentially in the Sca1(+) cells, whereas suppressing beta-catenin with a dominant negative, beta-engrailed, decreased self-renewal of the Sca1(+) cells. Understanding the radioresistance of progenitor cells may be an important factor in improving the treatment of cancer. The COMMA-Dbeta-geo cell line may provide a useful model to study the signaling pathways that control mammary progenitor cell regulation.
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Affiliation(s)
- Mercy S Chen
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, M638a Houston, TX 77030-3498, USA
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Groszer M, Erickson R, Scripture-Adams DD, Dougherty JD, Le Belle J, Zack JA, Geschwind DH, Liu X, Kornblum HI, Wu H. PTEN negatively regulates neural stem cell self-renewal by modulating G0-G1 cell cycle entry. Proc Natl Acad Sci U S A 2005; 103:111-6. [PMID: 16373498 PMCID: PMC1325011 DOI: 10.1073/pnas.0509939103] [Citation(s) in RCA: 240] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Previous studies have demonstrated that a small subpopulation of brain tumor cells share key characteristics with neural stem/progenitor cells in terms of phenotype and behavior. These findings suggest that brain tumors might contain "cancer stem cells" that are critical for tumor growth. However, the molecular pathways governing such stem cell-like behavior remain largely elusive. Our previous study suggests that the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) tumor suppressor gene, one of the most frequently mutated genes in glioblastomas, restricts neural stem/progenitor cell proliferation in vivo. In the present study, we sought to determine the role of PTEN in long-term maintenance of stem cell-like properties, cell cycle entry and progression, and growth factor dependence and gene expression. Our results demonstrate an enhanced self-renewal capacity and G(0)-G(1) cell cycle entry and decreased growth factor dependency of Pten null neural/stem progenitor cells. Therefore, loss of PTEN leads to cell physiological changes, which collectively are sufficient to increase the pool of self-renewing neural stem cells and promote their escape from the homeostatic mechanisms of proliferation control.
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Affiliation(s)
- Matthias Groszer
- Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
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Song Y, Chen Y, Liu Y. Switchable fluorescence behaviors of pyronine Y at different pH values upon complexation with biquinolino-bridged bis(β-cyclodextrin). J Photochem Photobiol A Chem 2005. [DOI: 10.1016/j.jphotochem.2005.04.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Xin L, Lawson DA, Witte ON. The Sca-1 cell surface marker enriches for a prostate-regenerating cell subpopulation that can initiate prostate tumorigenesis. Proc Natl Acad Sci U S A 2005; 102:6942-7. [PMID: 15860580 PMCID: PMC1087514 DOI: 10.1073/pnas.0502320102] [Citation(s) in RCA: 358] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Sca-1 (stem cell antigen-1) enriches for murine prostate cells capable of regenerating tubular structures containing basal and luminal cell lineages in a dissociated cell prostate regeneration system. Sca-1(+) fractions are enriched for cells at the G(0) stage of the cell cycle, and Sca-1(+) cells cluster in the proximal region of prostatic tubules where replication-quiescent cells have been localized. Castration-induced enrichment for androgen-independent cells results in a concomitant enrichment for Sca-1(+) cells. Genetic perturbations of PTEN/AKT signaling in prostate-regenerating cells leads to the initiation of tumorigenesis, and cancer progression is associated with a dramatic increase in Sca-1(+) cells. Sca-1-enriched prostate-regenerating cells possess multiple stem/progenitor cell properties and can serve as targets for cancer initiation.
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Affiliation(s)
- Li Xin
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, and Howard Hughes Medical Institute, University of California, Los Angeles, CA 90095, USA
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Kathrein KL, Lorenz R, Innes AM, Griffiths E, Winandy S. Ikaros induces quiescence and T-cell differentiation in a leukemia cell line. Mol Cell Biol 2005; 25:1645-54. [PMID: 15713624 PMCID: PMC549358 DOI: 10.1128/mcb.25.5.1645-1654.2005] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Ikaros is a hematopoietic cell-specific zinc finger DNA binding protein that plays an important role in lymphocyte development. Genetic disruption of Ikaros results in T-cell transformation. Ikaros null mice develop leukemia with 100% penetrance. It has been hypothesized that Ikaros controls gene expression through its association with chromatin remodeling complexes. The development of leukemia in Ikaros null mice suggests that Ikaros has the characteristics of a tumor suppressor gene. In this report, we show that the introduction of Ikaros into an established mouse Ikaros null T leukemia cell line leads to growth arrest at the G0/G1 stage of the cell cycle. This arrest is associated with up-regulation of the cell cycle-dependent kinase inhibitor p27kip1, the induction of expression of T-cell differentiation markers, and a global and specific increase in histone H3 acetylation status. These studies provide strong evidence that Ikaros possesses the properties of a bona fide tumor suppressor gene for the T-cell lineage and offer insight into the mechanism of Ikaros's tumor suppressive activity.
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Affiliation(s)
- Katie L Kathrein
- Department of Microbiology-Immunology, Northwestern University Feinberg School of Medicine, 320 E. Superior St., Morton 6-639, Chicago, IL 60611, USA
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31
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Øster B, Bundgaard B, Höllsberg P. Human herpesvirus 6B induces cell cycle arrest concomitant with p53 phosphorylation and accumulation in T cells. J Virol 2005; 79:1961-5. [PMID: 15650224 PMCID: PMC544083 DOI: 10.1128/jvi.79.3.1961-1965.2005] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We studied the interactions between human herpesvirus 6B (HHV-6B) and its host cell. Productive infections of T-cell lines led to G1/S- and G2/M-phase arrest in the cell cycle concomitant with an increased level and enhanced DNA-binding activity of p53. More than 70% of HHV-6B-infected cells did not bind annexin V, indicating that the majority of cells were not undergoing apoptosis. HHV-6B infection induced Ser20 and Ser15 phosphorylation on p53, and the latter was inhibited by caffeine, an ataxia telangiectasia mutated kinase inhibitor. Thus, a productive HHV-6B infection suppresses T-cell proliferation concomitant with the phosphorylation and accumulation of p53.
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Affiliation(s)
- Bodil Øster
- Department of Medical Microbiology and Immunology, Bartholin Building, University of Aarhus, DK-8000 Aarhus C, Denmark
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32
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Wei WH, Zhang J, Zhang YB, Zhou L, Gui JF. Genetic heterogeneity and ploidy level analysis among different gynogenetic clones of the polyploid gibel carp. ACTA ACUST UNITED AC 2003; 56:46-52. [PMID: 14566938 DOI: 10.1002/cyto.a.10077] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Some triploid and tetraploid clones have been identified in the gynogenetic gibel carp, Carassius auratus gibelio Bloch, by karyotypic and cytologic analyses over many years. Further, 5-20% males and karyotypic diversity have been found among their natural and artificial populations. However, the DNA contents and the relation to their ploidy level and chromosome numbers have not been ascertained, and whether normal meiosis occurs in spermatogenesis needs to be determined in the different clones. METHODS The sampled blood cells or sperms were mixed with blood cells from chicken or individual gibel carp and fixed in 70% pre-cooled ethanol overnight at 4 degrees C. The mixed cell pellets were washed 2-3 times in 1x phosphate buffered saline and then resuspended in the solution containing 0.5% pepsin and 0.1 M HCl. DNA was stained with propidium iodide solution (40 microg/mL) containing 4 kU/ml RNase. The measurements of DNA contents were performed with Phoenix Flow Systems. RESULTS Triploid clones A, E, F, and P had almost equal DNA content, but triploid clone D had greater DNA content than did the other four triploid clones. DNA content of clone M (7.01 +/- 0.15 pg/nucleus) was almost equal to the DNA content of clone D (5.38 +/- 0.06 pg/nucleus) plus the DNA content of common carp sperm (1.64 +/- 0.02 pg/nucleus). The DNA contents of sperms from clones A, P, and D were half of their blood cells, suggesting that normal meiosis occurs in spermatogenesis. CONCLUSIONS Flow cytometry is a powerful method to analyze genetic heterogeneity and ploidy level among different gynogenetic clones of polyploid gibel carp. Through this study, four questions have been answered. (a) The DNA content correlation among the five triploid clones and one multiple tetraploid clone was revealed in the gibel carp, and the contents increased with not only the ploidy level but also the chromosome number. (b) Mean DNA content was 0.052 pg in six extra chromosomes of clone D, which was higher than that of each chromosome in clones A, E, F, and P (about 0.032 pg/chromosome). This means that the six extra chromosomes are larger chromosomes. (c) Normal meiosis occurred during spermatogenesis of the gibel carp, because DNA contents of the sperms from clones A, P, and D were almost half of that in their blood cells. (d) Multiple tetraploid clone M (7.01 +/- 0.15 pg/nucleus) contained the complete genome of clone D (5.38 +/- 0.06 pg/nucleus) and the genome of common carp sperm (1.64 +/- 0.02 pg/nucleus).
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Affiliation(s)
- Wen-Hui Wei
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan Center for Developmental Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430-072, China
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Mourant JR, Yamada YR, Carpenter S, Dominique LR, Freyer JP. FTIR spectroscopy demonstrates biochemical differences in mammalian cell cultures at different growth stages. Biophys J 2003; 85:1938-47. [PMID: 12944306 PMCID: PMC1303365 DOI: 10.1016/s0006-3495(03)74621-9] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We have observed differences in the infrared spectra of viable fibroblast cells depending on whether the cells were in the exponential (proliferating) or plateau (nonproliferating) phase of growth. The spectral changes were observed even after correcting for cell number and volume, ruling out these trivial explanations. Several of the changes occurred for both transformed and normal cell lines and were greater for the normal cell line. The biochemical basis of the spectral changes was estimated by fitting the cell spectra to a linear superposition of spectra for the major biochemical components of mammalian cells (DNA, RNA, protein, lipids, and glycogen). The ratios of RNA/lipid and protein/lipid increased when the cells were in the exponential phase compared to the plateau phase of growth. The fits of cell spectra to individual biochemical components also demonstrated that DNA is a relatively minor spectroscopic component as would be expected biochemically. Contrary to other reports in the literature, our data demonstrate that determining DNA content or structure using Fourier transform infrared spectroscopy data is difficult due to the relatively small amount of DNA and the overlap of DNA bands with the absorption bands of other biochemical components.
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Affiliation(s)
- J R Mourant
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA.
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Chamras H, Ardashian A, Heber D, Glaspy JA. Fatty acid modulation of MCF-7 human breast cancer cell proliferation, apoptosis and differentiation. J Nutr Biochem 2002; 13:711-716. [PMID: 12550055 DOI: 10.1016/s0955-2863(02)00230-9] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Epidemiological studies suggest that dietary polyunsaturated fatty acids (PUFA) may influence breast cancer progression and prognosis. In order to study potential mechanisms of action of fatty acid modulation of tumor growth, we studied, in vitro, the influence of n-3 and n-6 fatty acids on proliferation, cell cycle, differentiation and apoptosis of MCF-7 human breast cancer cells. Both eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) inhibited the MCF-7 cell growth by 30% and 54%, respectively, while linoleic acid (LA) had no effect and arachidonic acid (AA) inhibited the cell growth by 30% (p < 0.05). The addition of vitamin E (10uM) to cancer cells slightly restored cell growth. The incubation of MCF-7 cells with PUFAs did not alter the cell cycle parameters or induce cell apoptosis. However, the growth inhibitory effects of EPA, DHA and AA were associated with cell differentiation as indicated by positive Oil-Red-O staining of the cells. Lipid droplet accumulation was increased by 65%, 30% and 15% in the presence of DHA, EPA and AA, respectively; (p < 0.05). These observations suggest that fatty acids may influence cellular processes at a molecular level, capable of modulating breast cancer cell growth.
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Affiliation(s)
- Hilda Chamras
- Division of Hematology/Oncology and Center for Human Nutrition, Department of Medicine, UCLA, Los Angeles, California, USA
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Scripture-Adams DD, Brooks DG, Korin YD, Zack JA. Interleukin-7 induces expression of latent human immunodeficiency virus type 1 with minimal effects on T-cell phenotype. J Virol 2002; 76:13077-82. [PMID: 12438635 PMCID: PMC136703 DOI: 10.1128/jvi.76.24.13077-13082.2002] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Latent human immunodeficiency virus type 1 (HIV-1) persists even in patients treated with antiretroviral therapy. New treatment strategies are therefore needed to eradicate this latent viral reservoir without reducing immune cell function. We characterize the interleukin-7 (IL-7)-induced stimulation of primary human T cells and thymocytes and demonstrate, using the SCID-hu model, that IL-7 induces substantial expression of latent HIV while having minimal effects on the cell phenotype. Thus, IL-7 is a viable candidate to activate expression of latent HIV and may facilitate immune clearance of latently infected cells.
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Affiliation(s)
- Deirdre D Scripture-Adams
- Department of Microbiology, Immunology, and Molecular Genetics, David Geffen School of Medicine, University of California at Los Angeles, 10833 Le Conte Avenue, Los Angeles, CA 90095, USA
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Eckstein DA, Penn ML, Korin YD, Scripture-Adams DD, Zack JA, Kreisberg JF, Roederer M, Sherman MP, Chin PS, Goldsmith MA. HIV-1 actively replicates in naive CD4(+) T cells residing within human lymphoid tissues. Immunity 2001; 15:671-82. [PMID: 11672548 DOI: 10.1016/s1074-7613(01)00217-5] [Citation(s) in RCA: 192] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Although HIV-1 gene expression is detected in naive, resting T cells in vivo, such cells are resistant to productive infection in vitro. However, we found that the endogenous microenvironment of human lymphoid tissues supports de novo infection and depletion of this population. Cell cycle analysis and DNA labeling experiments established that these cells were definitively quiescent and thus infected de novo. Quantitation of the "burst size" within naive cells further demonstrated that these cells were productively infected and contributed to the local viral burden. These findings demonstrate that lymphoid tissues support active HIV-1 replication in resting, naive T cells. Moreover, these cells are not solely reservoirs of latent virus but are permissive hosts for viral replication that likely targets them for elimination.
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Affiliation(s)
- D A Eckstein
- Gladstone Institute of Virology and Immunology, School of Medicine, University of California, San Francisco, San Francisco, CA 94141, USA
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Brooks DG, Kitchen SG, Kitchen CM, Scripture-Adams DD, Zack JA. Generation of HIV latency during thymopoiesis. Nat Med 2001; 7:459-64. [PMID: 11283673 DOI: 10.1038/86531] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The use of combination antiretroviral therapy results in a substantial reduction in viremia, a rebound of CD4+ T cells and increased survival for HIV-infected individuals. However, this treatment does not result in the total eradication of HIV. Rather, the virus is thought to remain latent in a subset of cells, where it avoids elimination by the immune system. In this state the virus is capable of reactivation of productive infection following cessation of therapy. These latently infected cells are very few in number and it has thus been difficult to determine their origin and to study the molecular nature of the latent viral genome. HIV replication is linked to cellular gene transcription and requires target cell activation. Therefore, should an activated, infected cell become transcriptionally inactive prior to cytopathic effects, the viral genome might be maintained in a latent state. We used the SCID-hu (Thy/Liv) mouse model to establish that activation-inducible HIV can be generated at high frequency during thymopoiesis, a process where previously activated cells mature towards quiescence. Moreover, we showed that these cells can be exported into the periphery where the virus remains latent until T-cell receptor stimulation, indicating that the thymus might be a source of latent HIV in humans.
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Affiliation(s)
- D G Brooks
- Department of Microbiology and Molecular Genetics, University of California at Los Angeles, Los Angeles, California, USA
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Schmid I, Hausner MA, Cole SW, Uittenbogaart CH, Giorgi JV, Jamieson BD. Simultaneous flow cytometric measurement of viability and lymphocyte subset proliferation. J Immunol Methods 2001; 247:175-86. [PMID: 11150548 DOI: 10.1016/s0022-1759(00)00323-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Combined analysis of DNA content and immunofluorescence on single cells by flow cytometry provides information on the proliferative response of cellular sub-populations in mixed cell preparations. However, the presence of considerable numbers of dead (nonviable) cells impairs accurate flow cytometric data analysis, mainly, because dead cells can bind antibodies non-specifically and show alterations in their DNA staining profiles. We developed a rapid method for identification of dead cells by fluorescence in cell preparations that are stained simultaneously for two-color immunofluorescence and DNA content. Cells are stained with 7-aminoactinomycin D (7-AAD) for dead cell discrimination and with fluorescein-isothiocyanate (FITC) and phycoerythrin (PE)-labeled monoclonal antibodies (mAb) for cell surface immunofluorescence. Diffusion of 7-AAD from stained, dead cells into unstained, live cells after cell permeabilization is blocked by the addition of its non-fluorescent analogue actinomycin D (AD). DNA is stained with red-excitable TO-PRO-3 iodide (TP3) which has an emission spectrum that can be effectively separated from the emissions of FITC, PE, and 7-AAD. TP3 staining is performed in the presence of ribonuclease A (RNAse) in phosphate-citrate buffer containing saponin (PCBS) at low pH. FITC fluorescence is sensitive to acid pH; therefore, PCBS is replaced after DNA staining with 1x PBS at pH 7.2 containing saponin to permit accurate detection of FITC immunofluorescence on the flow cytometer. We apply this method to the analysis of differential proliferation of lymphocyte subsets in cultures of human peripheral blood mononuclear cells (PBMC) with low viability.
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Affiliation(s)
- I Schmid
- Department of Hematology/Oncology, UCLA School of Medicine, 12-236 Factor Building, Los Angeles, CA 90095, USA.
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