Strategies for phenotyping apoptotic peripheral human lymphocytes comparing ISNT, annexin-V and 7-AAD cytofluorometric staining methods.
AuthorsLecoeur H,Ledru E,Prévost MC,Gougeon ML
JournalJournal of immunological methods
PubMed ID9461328
The present article compares the reliability of four previously described cytofluorometric methods of apoptosis quantification for phenotyping apoptotic human lymphocytes. Each of these assays detects distinct cellular alterations of the apoptotic process. Alteration in plasma membrane integrity can be evaluated following 7-AAD incorporation and the translocation of phosphatidylserine from the ... More
Features of medullary thymic epithelium implicate postnatal development in maintaining epithelial heterogeneity and tissue-restricted antigen expression.
AuthorsGillard GO, Farr AG
JournalJ Immunol
PubMed ID16670287
'Although putative thymic epithelial progenitor cells have been identified, the developmental potential of these cells, the extent of medullary thymic epithelium (mTEC) heterogeneity, and the mechanisms that mediate the expression of a wide range of peripheral tissue-restricted Ags (TRAs) by mTECs remain poorly defined. Here we have defined several basic ... More
A human gene coding for a membrane-associated nucleic acid-binding protein.
AuthorsSiess DC, Vedder CT, Merkens LS, Tanaka T, Freed AC, McCoy SL, Heinrich MC, Deffebach ME, Bennett RM, Hefeneider SH
JournalJ Biol Chem
PubMed ID10938276
'Studies to clone a cell-surface DNA-binding protein involved in the binding and internalization of extracellular DNA have led to the isolation of a gene for a membrane-associated nucleic acid-binding protein (MNAB). The full-length cDNA is 4.3 kilobases with an open reading frame of 3576 base pairs encoding a protein of ... More
Histone H3 phosphorylation and expression of cyclins A and B1 measured in individual cells during their progression through G2 and mitosis.
AuthorsJuan G, Traganos F, James WM, Ray JM, Roberge M, Sauve DM, Anderson H, Darzynkiewicz Z
JournalCytometry
PubMed ID9627219
'Phosphorylation of histone H3 (H3) on Ser-10 correlates with chromatin condensation at mitosis. A new monoclonal antibody (anti-H3-P) was developed that recognizes phosphorylated H3 (H3-P). This antibody was used in multiparameter flow cytometric analysis to relate H3 phosphorylation in individual human leukemic cells to the cells'' position in the cycle ... More
Olfactory horizontal basal cells demonstrate a conserved multipotent progenitor phenotype.
AuthorsCarter LA, MacDonald JL, Roskams AJ
JournalJ Neurosci
PubMed ID15215289
'Stem cells of adult regenerative organs share a common goal but few established conserved mechanisms. Within the neural stem cell niche of the mouse olfactory epithelium, we identified a combination of extracellular matrix (ECM) receptors that regulate adhesion and mitosis in non-neural stem cells [intercellular adhesion molecule-1 (ICAM-1), beta1, beta4, ... More
An essential role for CD44 variant isoforms in epidermal Langerhans cell and blood dendritic cell function.
AuthorsWeiss JM, Sleeman J, Renkl AC, Dittmar H, Termeer CC, Taxis S, Howells N, Hofmann M, Köhler G, Schöpf E, Ponta H, Herrlich P, Simon JC
JournalJ Cell Biol
PubMed ID9166413
'Upon antigen contact, epidermal Langerhans cells (LC) and dendritic cells (DC) leave peripheral organs and home to lymph nodes via the afferent lymphatic vessels and then assemble in the paracortical T cell zone and present antigen to T lymphocytes. Since splice variants of CD44 promote metastasis of certain tumors to ... More
Flow cytometric assay for the simultaneous analysis of cell-mediated cytotoxicity and effector cell phenotype.
AuthorsDerby E, Reddy V, Baseler M, Malyguine A,
JournalBiotechniques
PubMed ID11570508
Towards an understanding of apoptosis detection by SYTO dyes.
AuthorsWlodkowic D, Skommer J, Pelkonen J
JournalCytometry A
PubMed ID17200958
'BACKGROUND: SYTO probes are gaining momentum as reliable and easy to use markers of apoptotic cell death, but the phenomenon underlying reduced SYTO fluorescence in apoptotic cells as compared with normal cells is still not fully elucidated. Herein, we attempt to provide further insights into mechanisms of reduced SYTO16 fluorescence ... More
A rapid single-laser flow cytometric method for discrimination of early apoptotic cells in a heterogenous cell population.
AuthorsHerault O, Colombat P, Domenech J, Degenne M, Bremond JL, Sensebe L, Bernard MC, Binet C
JournalBr J Haematol
PubMed ID10086791
'A recently reported cytometric method described the possibility of discriminating apoptotic from necrotic cells using FITC-labelled annexin V and propidium iodide (PI). Nevertheless, the brightness of PI-staining and its extensive spectral emission overlap with phycoerythrin (PE) does not permit the study of a subset of a heterogenous cell population with ... More
Clonal isolation of muscle-derived cells capable of enhancing muscle regeneration and bone healing.
AuthorsLee JY, Qu-Petersen Z, Cao B, Kimura S, Jankowski R, Cummins J, Usas A, Gates C, Robbins P, Wernig A, Huard J
JournalJ Cell Biol
PubMed ID10973997
'Several recent studies suggest the isolation of stem cells in skeletal muscle, but the functional properties of these muscle-derived stem cells is still unclear. In the present study, we report the purification of muscle-derived stem cells from the mdx mouse, an animal model for Duchenne muscular dystrophy. We show that ... More
Automated quantitation of cell-mediated HIV type 1 infection of human syncytiotrophoblast cells by fluorescence in situ hybridization and laser scanning cytometry.
AuthorsDouglas GC, Thirkill TL, LaSalle J
JournalAIDS Res Hum Retroviruses
PubMed ID11350664
'Infection of human placental syncytiotrophoblast cells with HIV requires direct contact with infected leukocytes. In vitro investigations into mechanisms regulating placental HIV transmission and into the development of therapeutic interventions have been hampered by difficulties inherent in quantitating HIV levels in cocultures of infected lymphocytes and adherent multinucleated syncytiotrophoblast cells. ... More
Folinic acid antagonizes methotrexate-induced differentiation of monocyte progenitors.
AuthorsMöller B, Kukoc-Zivojnov N, Okamgba S, Kessler U, Puccetti E, Ottmann OG, Kaltwasser JP, Hoelzer D, Ruthardt M
JournalRheumatol Int
PubMed ID12070677
'OBJECTIVE: The anti-inflammatory action of low-dose methoxetrate (MTX) in the treatment of rheumatoid arthritis (RA) appears to be partially impaired by folate supplementation. Here we investigated whether a folate excess impairs monocyte differentiation, a putative anti-inflammatory action of low-dose MTX. METHODS: Monocyte differentiation of U937 promonocytic cells was assessed by ... More
Differential effects of deuterium oxide on the fluorescence lifetimes and intensities of dyes with different modes of binding to DNA.
AuthorsSailer BL, Nastasi AJ, Valdez JG, Steinkamp JA, Crissman HA
JournalJ Histochem Cytochem
PubMed ID9016307
'Deuterium oxide (D2O) increases both the fluorescence lifetime and the fluorescence intensity of the intercalating dyes propidium iodide (PI) and ethidium bromide (EB) when bound to nucleic acid structures. We have used spectroscopic analysis coupled with conventional and phase-sensitive flow cytometry to compare the alterations in intensity and lifetime of ... More
Texture analysis of fluorescence lifetime images of AT- and GC-rich regions in nuclei.
AuthorsMurata S, Herman P, Lakowicz JR
JournalJ Histochem Cytochem
PubMed ID11668197
'We used intensity and fluorescence lifetime microscopy (FLIM) of 3T3 nuclei to investigate the existence of AT-rich and GC-rich regions of the nuclear DNA. Hoechst 33258 (Ho) and 7-aminoactinomycin D (7-AAD) were used as fluorescence probes specific for AT and GC base pairs, respectively. YOYO-1 (Yo) was used as a ... More
A rapid method for measuring apoptosis and dual-color immunofluorescence by single laser flow cytometry.
AuthorsSchmid I, Uittenbogaart CH, Keld B, Giorgi JV
JournalJ Immunol Methods
PubMed ID8157993
'A sensitive method for quantification of cells undergoing apoptosis that permits the simultaneous measurement of dual-color cell surface immunofluorescence is presented. Unfixed cells are stained with 7-amino-actinomycin D (7-AAD) for discrimination of live from early apoptotic cells and from cells which have lost membrane integrity (late apoptotic or necrotic, dead ... More
Fluorescence lifetime imaging of nuclear DNA: effect of fluorescence resonance energy transfer.
AuthorsMurata S, Herman P, Lin HJ, Lakowicz JR
JournalCytometry
PubMed ID11042614
'BACKGROUND: DNA fluorescence dyes have been used to study DNA dynamics, chromatin structure, and cell cycle analysis. However, most microscopic fluorescence studies of DNA use only steady-state measurements and do not take advantage of the additional information content of the time-resolved fluorescence. In this paper, we combine fluorescence imaging of ... More
Detection of apoptosis and DNA replication by differential labeling of DNA strand breaks with fluorochromes of different color.
AuthorsLi X, Melamed MR, Darzynkiewicz Z
JournalExp Cell Res
PubMed ID8549670
'Selective DNA strand break induction by photolysis (SBIP) at sites that contain incorporated halogenated nucleotides has been recently proposed as a means of analyzing DNA replication and detecting proliferating cells. The presence of numerous in situ DNA strand breaks is also an inherent feature of apoptotic cells. The aim of ... More
Measurement of transient cDNA expression in mammalian cells using flow cytometric cell analysis and sorting.
AuthorsRice GC, Pennica D, Borree JA, Williams SR
JournalCytometry
PubMed ID2036916
'Generalized methods for quantitative and sensitive measurement of transient cDNA expression in mammalian cells using flow cytometry (FCM) are described. The techniques are applicable to a wide variety of cDNAs encoding intracellular or cell surface protein products through the use of immunofluorescence- or nonimmunofluorescence-based detection methods. The methods illustrated have ... More
Sensitive method for measuring apoptosis and cell surface phenotype in human thymocytes by flow cytometry.
AuthorsSchmid I, Uittenbogaart CH, Giorgi JV
JournalCytometry
PubMed ID7512891
'A rapid, gentle, and sensitive method for quantification of cells undergoing apoptosis is presented. The method allows the simultaneous determination of dual-color cell surface immunofluorescence. Cells are stained for 7 min with the vital dye Hoechst 33342 (HO342) for identification of live and apoptotic cells. 7-amino-actinomycin D (7-AAD) is added ... More
7-substituted actinomycin D analogs. Chemical and growth-inhibitory studies.
AuthorsSengupta SK, Tinter SK, Lazarus H, Brown BL, Modest EJ
JournalJ Med Chem
PubMed ID1059773
'The synthesis and biological activity of three 7-substituted actinomycin D derivatives are reported. Three such derivatives, 7-nitro-, 7-amino-, and 7-hydroxyactinomycin D, were synthesized via new methods which were first tested successfully with a chromophore model system. Of these, 7-nitro- and 7-aminoactinomycin D were assayed for growth inhibitory activity against mammalian ... More
Reduced susceptibility of nonobese diabetic mice to TNF-alpha and D-galactosamine-mediated hepatocellular apoptosis and lethality.
'Nonobese diabetic (NOD/LtJ or NOD) mice are resistant to doses of LPS and D-galactosamine that uniformly produce lethality in C57BL/6J (B6) mice (p < 0.01). Liver caspase-3-like activity, serum transaminase levels (both p < 0.05), and the numbers of apoptotic liver nuclei were also reduced in NOD compared with B6 ... More
Detection of changes in mitochondrial function during apoptosis by simultaneous staining with multiple fluorescent dyes and correlated multiparameter flow cytometry.
AuthorsPoot M, Pierce RH
JournalCytometry
PubMed ID10213196
'BACKGROUND: The possible relationships between changes in mitochondrial membrane potential and other mitochondrial functions during apoptosis remain controversial. METHODS: To detect concomitant changes in mitochondrial function during apoptosis, we performed correlated multiparameter flow cytometry after simultaneous cell staining with several dyes. RESULTS: After camptothecin treatment, nonapoptotic cells exhibited a concomitant ... More
Susceptibility and resistance to antigen-induced apoptosis in the thymus of transgenic mice.
AuthorsTarazona R, Williams O, Moskophidis D, Smyth LA, Tanaka Y, Murdjeva M, Wack A, Mamalaki C, Kioussis D
JournalJ Immunol
PubMed ID9605140
'Injection of TCR transgenic mice with antigenic peptide results in the deletion of immature thymocytes expressing the transgenic TCR. We have analyzed this process in mice transgenic for a TCR (F5) that recognizes a peptide from the influenza nucleoprotein (NP68). To determine whether deletion of immature thymocytes is the result ... More
Switching on of the proliferation or apoptosis of activated human T lymphocytes by IFN-gamma is correlated with the differential expression of the alpha- and beta-chains of its receptor.
AuthorsNovelli F, Bernabei P, Ozmen L, Rigamonti L, Allione A, Pestka S, Garotta G, Forni G
JournalJ Immunol
PubMed ID8757312
'To find out how physiologically secreted IFN-gamma controls either the proliferation or the apoptosis of human T lymphocytes, the kinetics of expression of the alpha- and beta-chains of its receptor (IFN-gamma R) were sequentially followed on T lymphocytes first activated with PHA and then cultured in the presence of IL-2, ... More
Actinomycin D binding to single-stranded DNA: sequence specificity and hemi-intercalation model from fluorescence and 1H NMR spectroscopy.
AuthorsWadkins RM, Jares-Erijman EA, Klement R, Rüdiger A, Jovin TM
JournalJ Mol Biol
PubMed ID8809179
'We have studied the sequence specificity in the binding of the potent antitumor drug actinomycin D (AMD) to single-stranded DNA (ssDNA) by fluorescence and NMR spectroscopy and by molecular modeling. The significant absorption and emission changes accompanying the interaction of the fluorescent derivative 7-amino-AMD with DNAs varying in length and ... More
Nitrosative Stress-induced Apoptosis through Inhibition of NF-kappa B.
Authors Marshall Harvey E; Stamler Jonathan S;
JournalJ Biol Chem
PubMed ID12091382
'Nitrosative stress produced by cytokines predisposes to apoptotic cell death. However, the molecular mechanism by which this occurs is not well understood. We have shown previously that nitric oxide (NO) regulates the activity of the anti-apoptotic transcription factor NF-kappaB. Here we demonstrate that the inhibition of NF-kappaB by NO sensitizes ... More
Modulation of chondrocyte proliferation by ascorbic acid and BMP-2.
AuthorsVenezian R, Shenker BJ, Datar S, Leboy PS
JournalJ Cell Physiol
PubMed ID9462695
'Chondrocytes show an unusual ability to thrive under serum-free conditions as long as insulin, thyroxine, and cysteine are present. Studies with sternal chondrocytes from chick embryos indicate that thymidine incorporation in chondrocytes cultured under serum-free conditions is 30-50% of that seen with fetal bovine serum (FBS). In contrast, skin fibroblast ... More
DNA distribution analysis of type II pneumocytes by laser flow cytometry: technical considerations.
AuthorsUhal BD, Rannels DE
JournalAm J Physiol
PubMed ID1928365
'Optimal conditions were established for determination of cell cycle phase fractions of freshly isolated or cultured adult rat type II pneumocytes (T2P). Propidium iodide staining of ethanol-fixed cells treated with ribonuclease (RNase) consistently yielded histograms with low coefficients of variation. Contaminating cells and cell clumps were eliminated during data acquisition ... More
Specific effects of surface amines on polystyrene nanoparticles in their interactions with mesenchymal stem cells.
AuthorsJiang X, Dausend J, Hafner M, Musyanovych A, Röcker C, Landfester K, Mailänder V, Nienhaus GU,
JournalBiomacromolecules
PubMed ID20166675
'We have investigated the uptake of cationic polystyrene nanoparticles by mesenchymal stem cells (MSCs) using confocal fluorescence microscopy and flow cytometry. Two types of nanoparticles of about 100 nm diameter with similar zeta potentials were employed in this study, plain polystyrene (PS) nanoparticles and amino-functionalized polystyrene (NPS) nanoparticles, each carrying ... More
Comparative evaluation of several DNA binding dyes in the detection of apoptosis-associated chromatin degradation by flow cytometry.
AuthorsTelford WG, King LE, Fraker PJ
JournalCytometry
PubMed ID1372208
'Mouse thymocytes readily undergo apoptosis-associated DNA degradation upon exposure to glucocorticoids or ionizing radiation. It has been previously shown that flow cytometric cell cycle analysis of propidium iodide-stained apoptotic thymocytes results in the appearance of a distinct cell cycle region (the A0 region) below the G0/G1 region. Cells in this ... More
CUBIC: a three-dimensional colored projection of Consort 30 generated trivariate flow cytometric data.
AuthorsGreimers R, Rongy AM, Schaaf-Lafontaine N, Boniver J
JournalCytometry
PubMed ID1764980
'The CUBIC program displays three-dimensional colored dot plots of flow cytometric trivariate data collected by unmodified commercial instruments (FACScan flow cytometer, FACS 440 cell sorter). Assuming a bimodal distribution of the fluorescence intensity of the cells, the eight theoretical subpopulations involved in a three-color fluorescence histogram are clearly localized in ... More
Mechanisms of acquired thymic tolerance in vivo: intrathymic injection of antigen induces apoptosis of thymocytes and peripheral T cell anergy.
AuthorsChen W, Sayegh MH, Khoury SJ
JournalJ Immunol
PubMed ID9570573
'Intrathymic injection of Ag induces Ag-specific tolerance in several clinically relevant experimental autoimmune and transplantation models. However, the exact mechanisms of acquired thymic tolerance in vivo remain unclear. We investigated the mechanisms of acquired thymic tolerance in mice that are transgenic for the TCR specific for peptide 323-339 of OVA. ... More
A new method for the simultaneous analysis of growth and death of immunophenotypically defined cells in culture.
AuthorsPrieto A, Reyes E, Diaz D, Hernandez-Fuentes MP, Monserrat J, Perucha E, Muñoz L, Vangioni R, de La Hera A, Orfao A, Alvarez-Mon M
JournalCytometry
PubMed ID10655563
'BACKGROUND: Internal standards have been used in flow cytometry methods to enumerate lymphoid subsets and hemopoietic progenitor cells ex vivo. However, the currently available methods cannot be readily applied to the analysis of cultured cells because of the frequent occurrence of cell death during in vitro assays. METHODS: This paper ... More
Comparison of multiple assays for kinetic detection of apoptosis in thymocytes exposed to dexamethasone or diethylstilbesterol.
AuthorsDonner KJ, Becker KM, Hissong BD, Ahmed SA
JournalCytometry
PubMed ID10554184
'BACKGROUND: Techniques to measure apoptosis are used to study a wide spectrum of conditions, from acquired immune deficiency syndrome (AIDS) to cancer to autoimmune diseases. Therefore, a critical comparison of common assays for apoptosis is warranted. METHODS: The kinetics of apoptosis induction in dexamethasone (DEX)-exposed thymocytes was examined after 2, ... More
Hydration changes for DNA intercalation reactions.
AuthorsQu X, Chaires JB
JournalJ Am Chem Soc
PubMed ID11273594
'The hydration changes that accompany the DNA binding of five intercalators (ethidium, propidium, proflavine, daunomycin, and 7-aminoactinomycin D) were measured by the osmotic stress method with use of the osmolytes betaine, sucrose, and triethylene glycol. Water uptake was found to accompany complex formation for all intercalators except ethidium. The difference ... More
MHC class I ligation of human T cells activates the ZAP70 and p56lck tyrosine kinases, leads to an alternative phenotype of the TCR/CD3 zeta-chain, and induces apoptosis.
AuthorsSkov S, Bregenholt S, Claesson MH
JournalJ Immunol
PubMed ID9120273
'Cross-linking of MHC class I (MHC-I) molecules on human T cells induces signal-transduction events, including activation of tyrosine kinases, tyrosine phosphorylation of phospholipase C-gamma 1, and elevation of the intracellular free calcium concentration. In this study, we demonstrate that the ZAP70 tyrosine kinase is tyrosine phosphorylated in Jurkat T cells ... More
7-Amino-actinomycin D as a cytochemical probe. I. Spectral properties.
AuthorsGill JE, Jotz MM, Young SG, Modest EJ, Sengupta SK
JournalJ Histochem Cytochem
PubMed ID1194669
'The optical absorption and fluorescence characteristics of 7-animo-actinomycin D were determined to evaluate its potential as a fluorescent cytochemical probe. At pH 7.0, the absorption maximum and fluorescence excitation maximum are both at 503 nm; the fluorescence emission is at 675 nm. When this compound forms complexes with DNA in ... More
Clonality and longevity of CD4+CD28null T cells are associated with defects in apoptotic pathways.
AuthorsVallejo AN, Schirmer M, Weyand CM, Goronzy JJ
JournalJ Immunol
PubMed ID11086066
'CD4(+)CD28(null) T cells are oligoclonal lymphocytes rarely found in healthy individuals younger than 40 yr, but are found in high frequencies in elderly individuals and in patients with chronic inflammatory diseases. Contrary to paradigm, they are functionally active and persist over many years. Such clonogenic potential and longevity suggest altered ... More
Live attenuated lentivirus infection elicits polyfunctional simian immunodeficiency virus Gag-specific CD8+ T cells with reduced apoptotic susceptibility in rhesus macaques that control virus replication after challenge with pathogenic SIVmac239.
AuthorsGenescà M, Rourke T, Li J, Bost K, Chohan B, McChesney MB, Miller CJ,
JournalJ Immunol
PubMed ID17878372
'HIV-specific CD8+ T cells that secrete multiple cytokines in response to Ag stimulation are associated with the control of virus replication during chronic HIV infection. To determine whether the presence of polyfunctional CD8+ T cell responses distinguishes protected and unprotected monkeys in a live attenuated lentivirus model, SIV Gag peptide-specific ... More
Simultaneous flow cytometric measurement of viability and lymphocyte subset proliferation.
'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 ... More
Differential chromatin structure-dependent binding of 7-aminoactinomycin D in normal and malignant bone marrow hematopoietic cells.
AuthorsStokke T, Holte H, Smeland EB, Lie SO, Steen HB
JournalCancer Res
PubMed ID1516056
'Chromatin structure-dependent binding of the DNA-specific dye 7-aminoactinomycin D (7-AMD) in leukemic and normal cells in bone marrow aspirates from childhood acute leukemia patients and patients without bone marrow neoplasia was assessed by multiparameter flow cytometry. Simultaneous staining with fluorescein isothiocyanate-labeled antibodies was needed in many cases for determination of ... More
Changes in cell nuclei during S phase: progressive chromatin condensation and altered expression of the proliferation-associated nuclear proteins Ki-67, cyclin (PCNA), p105, and p34.
AuthorsBruno S, Crissman HA, Bauer KD, Darzynkiewicz Z
JournalExp Cell Res
PubMed ID1831764
'Using multiparameter flow cytometry we have measured the nuclear DNA content of exponentially growing HL-60 cells in conjunction with protein content, nuclear forward light scatter, DNA in situ sensitivity to denaturation, DNA accessibility to 7-aminoactinomycin D (7-AMD), and content of the proliferation-associated proteins: cyclin (PCNA), p105, p34, and Ki-67. Multivariate ... More
DNA binding fluorochromes as probes for histone H1-chromatin interactions in situ.
AuthorsLoborg H, Rundquist I
JournalCytometry
PubMed ID9222106
'We have investigated using the DNA binding fluorochromes 7-aminoactinomycin (7-AAMD) and 4'',6-diamidino-2-phenylindole (DAPI) as cytochemical probes for linker histone (H1)-chromatin interactions in situ. Human lymphocytes, permeabilized with digitonin, were exposed to increasing concentrations of sodium chloride to remove ionically bound H1 from the nuclei. The cells were stained to equilibrium ... More
Cathepsin D and H2O2 stimulate degradation of thioredoxin-1: implication for endothelial cell apoptosis.
'Cathepsin D (CatD) is a lysosomal aspartic proteinase and plays an important role in the degradation of proteins and in apoptotic processes induced by oxidative stress, cytokines, and aging. All of these stimuli are potent inducers of endothelial cell apoptosis. Therefore, we investigated the role of CatD in endothelial cell ... More
Interactions between pairs of DNA-binding dyes: results and implications of chromosome analysis.
AuthorsLatt SA, Sahar E, Eisenhard ME, Juergens LA
JournalCytometry
PubMed ID6168450
'A number of DNA-binding dyes, with spectral properties making them suitable as components of energy donor-acceptor pairs, are described. If such pairs are used to stain metaphase chromosomes, and if the energy acceptor (e.g., actinomycin D or methyl green) has a binding specificity opposite to the binding or fluorescence specificity ... More
Probing chromatin structure in the early phases of apoptosis.
AuthorsFerlini C, Biselli R, Scambia G, Fattorossi A
JournalCell Prolif
PubMed ID8883466
'A typical flow cytometric marker of apoptosis is the appearance of a hypodiploid peak. This phenomenon is related to the chromatin fragmentation and loss that occurs during the late stages of the process. We describe herein the changes occurring at the chromatin level in purified nuclei preparations obtained from human ... More
Flow cytometric detection of activation-induced cell death (apoptosis) in peripheral blood lymphocyte subpopulations from healthy cats.
AuthorsHolznagel E, Hofmann-Lehmann R, Allenspach K, Hüttner S, Willett B, Groscurth P, Niederer E, Lutz H
JournalVet Immunol Immunopathol
PubMed ID8807772
'Human peripheral blood lymphocytes (PBLs) from healthy individuals are resistant to in vitro-induced apoptosis, but activated human lymphocytes can readily undergo apoptosis. The activation of human lymphocytes is accompanied by the upregulation of a cell surface antigen, the major histocompatibility complex (MHC) class II-antigen. Only a minority of PBLs are ... More
Aequorea green fluorescent protein analysis by flow cytometry.
'The isolation and expression of the cDNA for the green fluorescent protein (GFP) from the bioluminescent jellyfish Aequorea victoria has highlighted its potential use as a marker for gene expression in a variety of cell types (Chalfie et al.: Science 263: 802-805, 1994). The longer wavelength peak (470 nm) of ... More
Fluoro-Gold: An alternative viability stain for multicolor flow cytometric analysis.
AuthorsBarber L, Prince HM, Rossi R, Bertoncello I
JournalCytometry
PubMed ID10404151
'BACKGROUND: The viability stains propidium iodide (PI) and 7-amino-actinomycin D (7-AAD) are excited at 488 nm, as are the commonly used antibody conjugates fluorescein isothiocyanate (FITC), phycoerythrin (PE), and cyanine 5 dye covalently coupled to R-phycoerythrin (RPE-Cy5). When excited by a single laser, spectral overlap in the emission of PI ... More
Flow cytometry of DNA content and other indicators of proliferative activity.
AuthorsShapiro HM
JournalArch Pathol Lab Med
PubMed ID2471483
'Flow cytometric DNA content analysis, employing fluorescent stains that bind stoichiometrically to DNA, is widely used by researchers and clinicians to monitor cell growth kinetics and to detect abnormalities in nuclear DNA content in tumor cells. Measurement precision is critical because small differences in DNA content may be significant; plastic ... More
Apoptosis of T cells mediated by galectin-1.
AuthorsPerillo NL, Pace KE, Seilhamer JJ, Baum LG
JournalNature
PubMed ID7501023
'Galectin-1, a member of the family of beta-galactoside binding proteins, has growth regulatory and immunomodulatory activities. We report here that galectin-1, expressed by stromal cells in human thymus and lymph nodes, is present at sites of cell death by apoptosis during normal T-cell development and maturation. Galectin-1 induced apoptosis of ... More
Fluorometric detection of deoxyribonucleic acid synthesis; possibilities for interfacing bromodeoxyuridine dye techniques with flow fluorometry.
AuthorsLatt SA
JournalJ Histochem Cytochem
PubMed ID70459
'Fluorometric detection of the biosynthetic incorporation of 5-bromodeoxyuridine (BrdU) into deoxyribonucleic acid has permitted cytologic studies of chromosome structure, replication, and repair. Some of these phenomena, previously detected using BrdU-dye techniques on fixed microscopic preparations, should be particularly amenable to analogous experimentation in fluorescence flow systems. Problems involved in interfacing ... More
Kinetics of HL-60 cell entry to apoptosis during treatment with TNF-alpha or camptothecin assayed by the stathmo-apoptosis method.
AuthorsSmolewski P, Grabarek J, Lee BW, Johnson GL, Darzynkiewicz Z
JournalCytometry
PubMed ID11891718
'BACKGROUND: Duration of apoptosis, from onset to final disintegration of the cell, is often short and variable. The apoptotic index (AI), as a snapshot of a transient event of variable length, does not truly represent incidence of apoptosis in the studied cell population. We recently proposed to estimate the cumulative ... More
Increased apoptosis of CD45RO- T cells with aging.
AuthorsHerndon FJ, Hsu HC, Mountz JD
JournalMech Ageing Dev
PubMed ID9147365
'Increasing susceptibility to infectious and autoimmune phenomena have long been recognized to accompany advancing age in otherwise healthy individuals. Recently animal models of aging have suggested that age-associated immune dysfunction may correlate with defects in T cell apoptosis. We have examined activation-induced apoptosis defects in human peripheral T cells from ... More
TNF receptor 2-deficient CD8 T cells are resistant to Fas/Fas ligand-induced cell death.
AuthorsTeh HS, Seebaran A, Teh SJ
JournalJ Immunol
PubMed ID11046004
'Apoptotic cell death plays a fundamental role in the maintenance of tissue homeostasis in complex biological systems. It is also a major mechanism for keeping immune reactions in check. Members of the TNF family of receptors and cytokines are implicated in the regulation of apoptotic signals that shape the immune ... More
Pseudomonas aeruginosa-induced apoptosis is defective in respiratory epithelial cells expressing mutant cystic fibrosis transmembrane conductance regulator.
AuthorsCannon CL, Kowalski MP, Stopak KS, Pier GB
JournalAm J Respir Cell Mol Biol
PubMed ID12878584
'Chronic lung infection with Pseudomonas aeruginosa constitutes the most severe manifestation of cystic fibrosis, a scenario that results from defects in early clearance of the microbe. Early clearance involves epithelial cell ingestion of bacteria, rapid activation of nuclear factor-kappa B and cellular desquamation within minutes of P. aeruginosa infection, processes ... More
Texture analysis of fluorescence lifetime images of nuclear DNA with effect of fluorescence resonance energy transfer.
AuthorsMurata S, Herman P, Lakowicz JR
JournalCytometry
PubMed ID11169573
'BACKGROUND: Fluorescence lifetime imaging microscopy (FLIM) is becoming an important tool in cellular imaging. In FLIM, the image contrast is concentration insensitive, whereas it is sensitive to the local environment and interactions of fluorophores such as fluorescence resonance energy transfer (RET). METHODS: Fluorescence microscopy, lifetime imaging, and texture analysis were ... More
'We previously demonstrated that hematopoietic cell protein-tyrosine phosphatase is one of the molecules that can transduce Fas-mediated apoptosis signals in lymphoid cells. The present study analyzed the effect of defective Fas signaling on the T cell phenotype and apoptosis function in hematopoietic cell protein-tyrosine phosphatase-deficient motheaten mice. Viable motheaten (me(v)/me(v)) ... More
Specific deficiency of p56lck expression in T lymphocytes from type 1 diabetic patients.
'Peripheral T lymphocyte activation in response to TCR/CD3 stimulation is reduced in type 1 diabetic patients. To explore the basis of this deficiency, a comprehensive analysis of the signal transduction pathway downstream of the TCR/CD3 complex was performed for a cohort of patients (n = 38). The main result of ... More
Pairs of fluorescent dyes as probes of DNA and chromosomes.
AuthorsLatt SA, Sahar E, Eisenhard ME
JournalJ Histochem Cytochem
PubMed ID86582
'If two fluorescent dyes with different binding or fluorescence specificities are used simultaneously to stain DNA or chromosomes, the ratio of their fluorescent signals can provide information about base composition or base analogue substitution. Energy transfer between such dye pairs, possible if the fluorescence spectrum of one overlaps the absorption ... More
Unique signaling properties of B cell antigen receptor in mature and immature B cells: implications for tolerance and activation.
AuthorsBenschop RJ, Brandl E, Chan AC, Cambier JC
JournalJ Immunol
PubMed ID11591737
'Immature B cells display increased sensitivity to tolerance induction compared with their mature counterparts. The molecular mechanisms underlying these differences are poorly defined. In this study, we demonstrate unique maturation stage-dependent differences in B cell Ag receptor (BCR) signaling, including BCR-mediated calcium mobilization responses. Immature B cells display greater increases ... More
Inhibitory properties of nucleic acid-binding ligands on protein synthesis.
AuthorsMalina A, Khan S, Carlson CB, Svitkin Y, Harvey I, Sonenberg N, Beal PA, Pelletier J
JournalFEBS Lett
PubMed ID15620694
'The use of small molecule inhibitors in the study of cellular processes is a powerful approach to understanding gene function. During the course of a high throughput screen for novel inhibitors of eukaryotic translation, we identified a number of nucleic acid binding ligands that showed activity in our assay. When ... More
Prediction of growth sensitivity of acute promyelocytic leukemia cells to granulocyte colony-stimulating factor using 7AAD/PY during administration of all-trans retinoic acid.
AuthorsToba K, Koike T, Wang Y, Nagai K, Takahashi H, Hashimoto S, Uesugi Y, Aizawa Y
JournalInt J Hematol
PubMed ID9277051
'We discussed utility of cell cycle and phenotypic analysis of acute promyelocytic leukemia (APL) cells using 7AAD/PY for the prediction of efficacy and risks of all-trans retinoic acid (ATRA) and granulocyte colony-stimulating factor (G-CSF) administration to patients with APL. Serial changes in phenotype and cell kinetics of APL cells from ... More
Essential role of survivin, an inhibitor of apoptosis protein, in T cell development, maturation, and homeostasis.
AuthorsXing Z, Conway EM, Kang C, Winoto A
JournalJ Exp Med
PubMed ID14699085
'Survivin is an inhibitor of apoptosis protein that also functions during mitosis. It is expressed in all common tumors and tissues with proliferating cells, including thymus. To examine its role in apoptosis and proliferation, we generated two T cell-specific survivin-deficient mouse lines with deletion occurring at different developmental stages. Analysis ... More
Phagocytosis of apoptotic cells assessed by flow cytometry using 7-Aminoactinomycin D.
AuthorsGaforio JJ, Serrano MJ, Algarra I, Ortega E, Alvarez de Cienfuegos G
JournalCytometry
PubMed ID12210605
'BACKGROUND: Apoptotic cells are recognized specifically by macrophages and are cleared rapidly by phagocytosis. However, the recognition mechanisms involved in the clearance of apoptotic cells by macrophages are still not fully understood. Therefore, new methods must be designed to better our understanding of the mechanisms of interaction between macrophages and ... More
Humoral immune responses in Cr2-/- mice: enhanced affinity maturation but impaired antibody persistence.
AuthorsChen Z, Koralov SB, Gendelman M, Carroll MC, Kelsoe G
JournalJ Immunol
PubMed ID10779753
'Deficiency in CD21/CD35 by disruption of the Cr2 loci leads to impaired humoral immune responses. In this study, we detail the role of CD21/CD35 on Ab responses to the hapten (4-hydroxy-3-nitrophenyl)acetyl conjugated to chicken gamma-globulin. Surprisingly, Cr2-/- mice generate significant Ab responses and germinal center (GC) reactions to low doses ... More
Intracellular IL-1beta is an inhibitor of Fas-mediated apoptosis.
AuthorsTatsuta T, Cheng J, Mountz JD
JournalJ Immunol
PubMed ID8892627
'Fas-mediated apoptosis has been shown to be mediated by the IL-1beta converting enzyme (ICE) pathway. To determine the relationship between ICE and its substrate IL-1beta, we examined six human cell lines for susceptibility to Fas-mediated apoptosis and Fas induction of ICE-like activity. The human B lymphoblastoid cell line SKW6.4 and ... More
Autocrine and paracrine apoptosis are mediated by differential regulation of Fas ligand activity in two distinct Jurkat T cell populations.
AuthorsSu X, Cheng J, Liu W, Liu C, Wang Z, Yang P, Zhou T, Mountz JD
JournalJ Immunol
PubMed ID9605126
'Fas ligand (FasL) produced by activated T cells mediates autocrine-induced apoptosis to limit T cell expansion. To investigate the regulation of FasL activity, Jurkat cells were stably transfected with a 2.3-kb fragment of human FasL promoter that controlled the expression of a GFP reporter gene. Two populations of Jurkat cells ... More
Norepinephrine accelerates HIV replication via protein kinase A-dependent effects on cytokine production.
AuthorsCole SW, Korin YD, Fahey JL, Zack JA
JournalJ Immunol
PubMed ID9670934
'To explore the role of sympathetic nervous system activation in HIV pathogenesis, we examined the effect of the neuroeffector molecule norepinephrine (NE) on HIV-1 replication in quiescently infected PBMCs that were subsequently activated with Abs to CD3 and CD28. NE accelerated HIV-1 replication at concentrations ranging from 10(-8) to 10(-5) ... More
Integrin functions play a key role in the differentiation of thymocytes in vivo.
AuthorsSchmeissner PJ, Xie H, Smilenov LB, Shu F, Marcantonio EE
JournalJ Immunol
PubMed ID11564787
'T cells express a variety of surface proteins as they develop to maturity in the thymus. In addition to the TCR-CD3 complex and the two major coreceptors, CD4 and CD8, other surface proteins expressed include receptors for cytokines, growth factors, counterreceptors, and extracellular matrix molecules. To determine the role of ... More
Quantitative relationship between MHC class II-superantigen complexes and the balance of T cell activation versus death.
'The binding of bacterial superantigens (SAgs) is profoundly affected by the nature of the MHC class II-associated antigenic peptide. It was proposed that this limitation in the density of SAgs displayed at the surface of APCs is important for efficient TCR serial triggering as well as for preventing apoptosis of ... More
Adjuvant-induced survival signaling in clonally expanded T cells is associated with transient increases in pAkt levels and sustained uptake of glucose.
AuthorsSengupta S, Chilton PM, Mitchell TC
JournalImmunobiology
PubMed ID16325488
'Immunological adjuvants help increase the number of T cells responding to an immunizing antigen. Part of the increase is due to promotion of survival of clonally expanded T cells in the face of waning antigen load and subsequent growth-factor withdrawal. The phosphatidylinositide-3 kinase (PI3-kinase)/Akt pathway is activated upon T cell ... More
A cytofluorometric method for the simultaneous detection of both intracellular and surface antigens of apoptotic peripheral lymphocytes.
AuthorsLecoeur H, Ledru E, Gougeon ML
JournalJ Immunol Methods
PubMed ID9776571
'The aim of this study was to define a simple and reliable method to detect simultaneously surface and intracellular antigens in apoptotic peripheral human lymphocytes. This approach requires a permeabilizing procedure for intracellular access of mAbs, which raises the important question of the influence of this procedure on parameters which ... More
Cell division is not a "clock" measuring acquisition of competence to produce IFN-gamma or IL-4.
AuthorsBen-Sasson SZ, Gerstel R, Hu-Li J, Paul WE
JournalJ Immunol
PubMed ID11123283
'Naive CD4 T cells acquire the potential to produce IFN-gamma and IL-4 by culture in the presence of their cognate Ag, APC, and appropriate cytokines. In this study, we show that commitment to IFN-gamma production on the part of rigorously purified naive CD4 T cells can occur without cell division. ... More
Measurement of apoptosis and proliferation of bone marrow plasma cells in patients with plasma cell proliferative disorders.
AuthorsWitzig TE, Timm M, Larson D, Therneau T, Greipp PR
JournalBr J Haematol
PubMed ID10027725
'The proliferative rate of malignant plasma cells, as measured by the plasma cell labelling index (PCLI), is an important prognostic factor in multiple myeloma (MM); however, the PCLI alone is probably Inadequate to describe tumour growth because it ignores the idea that myeloma cells may have a reduced rate of ... More
Comparison of volumetric capillary cytometry with standard flow cytometry for routine enumeration of CD34+ cells.
AuthorsCabezudo E, Querol S, Cancelas JA, García J
JournalTransfusion
PubMed ID10504123
'BACKGROUND: This study assesses the feasibility of a new volumetric cytometry system for the enumeration of CD34+ cells in apheresis components, peripheral blood, and cord blood samples in routine laboratory work. This system is compared with the following flow cytometry protocols: Milan, ISHAGE, ISHAGE with 7-AAD, and flow-count fluorospheres. STUDY ... More
Actinomycin D binding to unstructured, single-stranded DNA.
AuthorsYoo H, Rill RL
JournalJ Mol Recognit
PubMed ID11391784
'Actinomycin D is an anticancer antibiotic best know for inhibiting transcription by binding double-stranded DNA. Tight, sequence selective binding of actinomycin to single-stranded DNA is also known, however, and is implicated in biological activities including inhibition of (-) strand transfer by HIV reverse transcriptase. Oligonucleotide d(GTTAACCATAG) is one of the ... More
Phenotyping of epidermal dendritic cells: clinical applications of a flow cytometric micromethod.
AuthorsWollenberg A, Wen S, Bieber T
JournalCytometry
PubMed ID10486527
'BACKGROUND: The differential diagnosis of inflammatory skin diseases is largely based on the patient''s history and the morphological analysis of the skin lesion. Laboratory data, such as serum IgE-level and prick and patch tests, may be helpful but do not assess individual lesions. The assumption of our approach is that ... More
Immunochemical quantitation of bromodeoxyuridine: application to cell-cycle kinetics.
AuthorsDolbeare F, Selden JR
JournalMethods Cell Biol
PubMed ID7861968
'We have described several laboratory procedures for the immunochemical staining of the halopyrimidines, BrdUrd and IdUrd, in cell suspensions for flow cytometry and a method for staining histological sections on slides. Halogenated pyrimidine quantitation allows cell-cycle parameters, including total cell-cycle time, phase durations, and growth fraction to be determined. We ... More
Detection of bromodeoxyuridine incorporation by alteration of the fluorescence emission from nucleic acid binding dyes using only an argon ion laser.
AuthorsFrey T
JournalCytometry
PubMed ID7875038
'A method was developed that uses paired DNA dyes to detect the incorporation of bromodeoxyuridine (BrdUrd) into cellular DNA and requires only 488 nm excitation. The fluorescence of thiazole blue, TO-PRO-3, and LDS-751 was found to be enhanced by the presence of BrdUrd in DNA. Pairing LDS-751, thiazole blue, or ... More
CD40 ligand is pivotal to efficient control of virus replication in mice infected with lymphocytic choriomeningitis virus.
AuthorsThomsen AR, Nansen A, Christensen JP, Andreasen SO, Marker O
JournalJ Immunol
PubMed ID9794385
'CD40 ligand (CD40L) is an important molecule that is known to be involved in T-B collaboration and certain aspects of cell-mediated immunity. However, its role in antiviral immunity has not been clearly defined as of yet. Therefore, mice with a targeted defect in the gene encoding this molecule were infected ... More
A functional comparison of CD34 + CD38- cells in cord blood and bone marrow.
AuthorsHao QL, Shah AJ, Thiemann FT, Smogorzewska EM, Crooks GM
JournalBlood
PubMed ID7579341
'We present cell cycling and functional evidence that the CD34+CD38- immunophenotype can be used to define a rare and primitive subpopulation of progenitor cells in umbilical cord blood. CD34+CD38- cells comprise 0.05% +/- 0.08% of the mononuclear cells present in cord blood. Cell cycle analysis with the fluorescent DNA stain ... More
Quantification of apoptotic events in pure and heterogeneous populations of cells using the flow cytometer.
AuthorsFraker PJ, King LE, Lill-Elghanian D, Telford WG
JournalMethods Cell Biol
PubMed ID7609660
'The rapid and highly quantitative nature of flow cytometric cell cycle analysis for determining the proportion of apoptotic cells in a population makes it the method of choice for a variety of studies requiring quantitative information about cell death. Furthermore, by employing multiparameter analysis including phenotypic labeling, FACS makes it ... More
Side population in adult murine epidermis exhibits phenotypic and functional characteristics of keratinocyte stem cells.
AuthorsRedvers RP, Li A, Kaur P
JournalProc Natl Acad Sci U S A
PubMed ID16920793
'Based on functional studies in the bone marrow, it has been suggested that the ability to efflux Hoechst 33342 may represent a universal stem cell trait. In this phenotypic and functional characterization of the Hoechst side population (SP) in adult murine epidermis, we demonstrate that these cells are a rare ... More
Segregation of RNA and separate packaging of DNA and RNA in apoptotic bodies during apoptosis.
AuthorsHalicka HD, Bedner E, Darzynkiewicz Z
JournalExp Cell Res
PubMed ID11035919
'Apoptosis is characterized by a complex and remarkably ordered choreography of events consisting of the preparatory and execution steps that all culminate in disposal of the cell remnants. The disposal occurs in a manner that is the least destructive to the tissue: the remains of nuclear chromatin and cytoplasm are ... More
Effect of fixatives on CD34+ cell enumeration.
AuthorsKeeney M, Chin-Yee I, Nayar R, Sutherland DR
JournalJ Hematother Stem Cell Res
PubMed ID10634168
7-Amino-actinomycin D complexes with deoxynucleotides as models for the binding of the drug to DNA.
Fine structure of chromosomes as revealed by fluorescence analysis.
AuthorsMoutschen J
JournalProg Biophys Mol Biol
PubMed ID60772
Studies of the binding of actinomycin and related compounds to DNA.
AuthorsMüller W, Crothers DM
JournalJ Mol Biol
PubMed ID4107107
Improved measurement of calcium mobilization by flow cytometry.
AuthorsBurns JM, Lewis GK
JournalBiotechniques
PubMed ID9421629
Fluorescence labeling and microscopy of DNA.
AuthorsArndt-Jovin DJ, Jovin TM
JournalMethods Cell Biol
PubMed ID2467179
The use of phycobiliproteins as fluorescent labels in immunoassay.
AuthorsKronick MN
JournalJ Immunol Methods
PubMed ID3528294
Reversible depression of spontaneous brain electrical activity induced by actinomycin D and 7-aminoactinomycin D in rats.
AuthorsUezu E, Takada Y, Mishima N
JournalExperientia
PubMed ID7151959
Various types of actinomycin (C,D,S2, I and V) and 7-amino-analogue of actinomycin D were injected into the right lateral ventricle of the brain through a chronically implanted cannula. In rats but not in mice actinomycin D, actinomycin S2 and 7-aminoactinomycin D caused depression of EEG, while cardiac and respiratory activity ... More
An 11-color flow cytometric assay for identifying, phenotyping, and assessing endocytic ability of peripheral blood dendritic cell subsets in a single platform.
AuthorsWang JC, Kobie JJ, Zhang L, Cochran M, Mosmann TR, Ritchlin CT, Quataert SA,
JournalJ Immunol Methods
PubMed ID19049809
Human peripheral blood dendritic cells (PBDC) are a rare population comprised of several distinctive subsets. Analysis of these cells has been hindered by their low frequency. In this study, we report a novel direct ex vivo 11-color flow cytometric assay that combines subset identification with analysis of activation status and ... More
Requirement for croquemort in phagocytosis of apoptotic cells in Drosophila.
AuthorsFranc NC, Heitzler P, Ezekowitz RA, White K
JournalScience
PubMed ID10373118
Macrophages in the Drosophila embryo are responsible for the phagocytosis of apoptotic cells and are competent to engulf bacteria. Croquemort (CRQ) is a CD36-related receptor expressed exclusively on these macrophages. Genetic evidence showed that crq was essential for efficient phagocytosis of apoptotic corpses but was not required for the engulfment ... More
DNA binding studies of 7-bulky-substituted actinomycin analogues.
AuthorsBrennan TF, Sengupta SK
JournalJ Med Chem
PubMed ID6827565
The DNA binding properties of several 7-substituted aralkylaminoactinomycin D analogues have been studied by spectrophotometry, DNA melting temperature studies, DNA-drug dissociation studies, and circular dichroism. Despite the presence of such bulky groups as 2-pyrrolylmethylamino or 3,4-dichlorobenzylamino at the 7 position, these analogues bind to DNA, inhibit RNA synthesis, and exhibit ... More
Antibiotic susceptibility testing by flow cytometry.
AuthorsPore RS
JournalJ Antimicrob Chemother
PubMed ID7706157
The first significant development in antibiotic susceptibility testing in recent years may be the flow cytofluorometric susceptibility test (FCST). The advanced analytical capability of the flow cytometer has provided the means to measure microbial diversity in culture. Membrane integrity and other indicators of microbial viability can be evaluated on a ... More
Myc requires distinct E2F activities to induce S phase and apoptosis.
AuthorsLeone G, Sears R, Huang E, Rempel R, Nuckolls F, Park CH, Giangrande P, Wu L, Saavedra HI, Field SJ, Thompson MA, Yang H, Fujiwara Y, Greenberg ME, Orkin S, Smith C, Nevins JR
JournalMol Cell
PubMed ID11511364
Previous work has shown that the Myc transcription factor induces transcription of the E2F1, E2F2, and E2F3 genes. Using primary mouse embryo fibroblasts deleted for individual E2F genes, we now show that Myc-induced S phase and apoptosis requires distinct E2F activities. The ability of Myc to induce S phase is ... More