Cytoplasmic Transfer Between Adhered Cells by Cell Fusion Through Microslit K.-I

Total Page:16

File Type:pdf, Size:1020Kb

Cytoplasmic Transfer Between Adhered Cells by Cell Fusion Through Microslit K.-I CYTOPLASMIC TRANSFER BETWEEN ADHERED CELLS BY CELL FUSION THROUGH MICROSLIT K.-I. Wada1,2, E. Kondo1, K. Hosokawa1*, Y. Ito2 and M. Maeda1 1Bioengineering Laboratory and 2Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan ABSTRACT This paper describes a novel cell fusion method which induces cell fusion between adhered cells through a microslit for preventing nuclear mixing. For this purpose, a microfluidic device which had 105 cell paring structures (CPSs) making cell pairs through microslits with 2.1 ± 0.3 μm width was fabricated. After trapping NIH3T3 cells with hydrodynamic forces at the CPSs, the cells were fused through the microslit by the Sendai virus envelope method. With following timelapse observation, we discovered that the spread cells were much less susceptible to nuclear migration passing through the microslit compared with round cells. This finding will provide an effective method for cell fusion without nuclear mixing, and will lead to an efficient method for reprogramming and transdifferentiation of target cells toward regenerative medicine. KEYWORDS: Cell fusion, Microslit, Cytoplasmic transfer, Adhered cell INTRODUCTION The invention of induced pluripotent stem (iPS) cells[1] gave a great impact on regenerative medicine in term of cellular resources production, but some critical issues still remain such as slow and inefficient induction process, risk for tumorigenesis, and contamination of exogenous genes. Therefore, other various approaches to produce cellular resources should be explored. Cell fusion with differentiated[2] or embryonic stem (ES)[3] cells induces transdifferentiation or reprogramming, respectively. These results indicate a possibility that some factors in the cytoplasm have a capability to alter gene expression property to induce transdifferentiation or reprogramming. However, transfer of those factors by common cell fusion is accompanied by nuclear mixing resulting in abnormal karyotypes, thus being inapplicable to regenerative medicine. If cell fusion without nuclear mixing is realized, it will be a feasible method to transfer the cytoplasm, and thus provide a novel approach to induce transdifferentiation or reprogramming. One promising method to avoid abnormal karyotypes accompanied with cell fusion is to separate the nuclei of the fusing cells with a microstructure: cell fusion through a microfabricated aperture smaller than the nuclei. This kind of experiments has already been reported in some previous studies[4,5], however, in these studies cell fusion was induced between suspended cells. Because adhesive cells require adhesion to maintain their intrinsic functions[6] and cytoplasmic compositions are often different between adhered and suspended conditions7, fusion between the adhered cells may be essential to induce desired transdifferentiation or reprogramming. Then, in this study, we tried to induce cell fusion between adhered cells without nuclear mixing by using a newly developed microfabricated device. THEORY In order to transfer cytoplasm by cell fusion-based method keeping karyotype normal, it is required to avoid nuclear mixing accompanied by cell fusion. The theory for the prevention of nuclear mixing is illustrated in Fig. 1. After making cells pair in a microfabricated device, cells adhere and spread on Fig. 1: The theory for the prevention of nuclear mixing. Cell fusion is in- the culture substrate. Then, cell duced between adhered cells through the microslit (white arrow head). fusion is induced through a small aperture termed “microslit” to make a strictured cytoplasmic connection. This structure prevents nuclear migration to the fusion partner. In contrast, the cytoplasm is exchanged between fused cells by passive diffusion and/or active transport (i.e. cytoplasmic transfer). We expect that this cytoplasmic transfer from certain donor cells induces transdifferentiation or reprogramming of the recipient cells. The cell fusion system used in this study is shown in Fig. 2. A poly(dimethysiloxane) (PDMS) chip is placed on a 35 mm cell culture dish to provide a good cell adhesion substrate. The PDMS chip has 105 cell pairing structures (CPSs) with a microslit (2.1 ± 0.3 μm wide) in the microchannel with a 500 μm width and a 28 μm depth. The CPS is designed to achieve a cell pair through the microslit by hydrodynamic force. The heterogeneous cell pairs are made by chance when a mixed suspension of the two types of cells is injected. Except for the microslit, the paired cells are separated with a 136 μm long separation wall to avoid unwanted cell-cell contact bypassing the microslit. The solution is basically flowed by gravity. 978-0-9798064-6-9/µTAS 2013/$20©13CBMS-0001 1329 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences 27-31 October 2013, Freiburg, Germany Fig. 2: The cell fusion system used in this study. (A) Photo, top view, and detailed view are illustrated. The PDMS microfluidic chip is confined in a 35 mm culture dish. CPS: cell paring structure. (B) Image of a CPS. Arrow head: microslit, Pi: support pillar, Po: trap pocket, Wa: separation wall. (C) Overlaid image of a achieved heterogeneous cell pair of CgNr3T3 (upper) and Nr3T3 (lower) by centrifuge-driven flow. Bars = 50 μm. EXPERIMENTAL To monitor the cell fusion and subsequent nuclear behavior, two cell lines named CgNr3T3 (cytoplasm-green and nucleus-red) and Nr3T3 (nucleus-red) were established from NIH3T3 cells by stable transfection of EGFP and H2B- mCherry expression vectors, respectively. After applying 10-40 uL of cell suspension of CgNr3T3 and Nr3T3 with 2×106/mL into the inlet, the microfluidic device was subjected to centrifuge at 60×g for 1 min to accelerate the cell trapping process. Then, inlet was rinsed twice and filled with 40 uL of the culture medium, and the microfluidic device was set on a timelapse microscopy chamber under a condition of 100% humidity, 5% CO2, and 36 °C. Then, 4 μL of Sendai virus envelope (HVJ-E) (Ishihara Sangyo, Japan) suspension was added to the culture medium in the inlet. From the addition of HVJ-E, 5 min-interval timelapse observation was performed for 5 h. RESULTS AND DISCUSSION We carried out 13 independent experiments, and selected a total of 66 heterogeneous cell pairs of CgNr3T3 and Nr3T3 for timelapse observation. The cell fusion was detected by transfer of EGFP from the CgNr3T3 cell to the Nr3T3 cell. In 14 pairs (21% of 66 pairs), the cells successfully fused through the microslit in 5 h. The other 52 cell pairs failed to fuse, mainly due to cell migration, lack of cell-cell contact, or cell death. In 7 of the 14 fused pairs, we observed suc- cessful retention of the nuclei: both of the nuclei in the fused cells did not pass through the microslit for 5 h. In these cas- es, the most cells were in spread shapes, while a few cells took round shapes in short periods. (Fig. 3A, C). In contrast, in the other 7 fused pairs, the nucleus of one of the cells migrated to its fusion partner through the microslit. With one ex- ception, the migration of the nuclei started from round cells (Fig. 3B, D). These two events—cell rounding-up and nucle- ar migration—seem to be strongly correlated, because both of the events were relatively rare in terms of time periods in which they occurred. In other words, these data suggest that spread cells are much less susceptible to nuclear migration passing through the microslit compared with round cells. CONCLUSION We succeeded in induction of cell fusion between adhered cells through the microslit by using a newly developed mi- crofluidic device, and found the importance of cell adhesion/spreading on the culture substrate for prevention of nuclear mixing. Our technique would be a unique way to study functional cytoplasmic transfer without nuclear mixing, and also would be a promising method for production of cellular resources applicable to regenerative medicine as well as basic cell biology. ACKNOWLEDGEMENTS We thank for Laboratory for Animal Resources and Genetic Engineering, Center for Developmental Biology, RIKEN Kobe for providing the pcDNA3-H2B-EGFP and the pcDNA3-H2B-mCherry vectors. 1330 Fig. 3: Cellular behavior after cell fusion through the microslit. (A) Typical timelapse images of a cell pair of CgNr3T3 (upper) and Nr3T3 (lower), in which both nuclei in the pair did not pass through the microslit. The cell fusion was judged by the transfer of EGFP (0 min). (B) Typical timelapse images of a cell pair of CgNr3T3 (upper) and Nr3T3 (lower), in which one nucleus passed through the microslit (20 min). (C) Position of nuclei in the fused cell pairs in which both nuclei did not pass through the microslit. Each nucleus was randomly selected from the two nuclei of the cell pair. (D) Position of the nuclei which passed through the microslit toward the fusion partner cell. In C and D, the nuclear position (d) was traced as a distance from the separation wall to the middle point of the nu- clei, and the blue and red lines represent the cell shapes: spread and round shapes, respectively. REFERENCES [1] K. Takahashi and S. Yamanaka, Cell, vol. 126, no. 4, pp. 663-676, Aug.2006 [2] H. M. Blau, C. P. Chiu and C. Webster, Cell, vol. 32, no. 4, pp. 1171-1180, Apr.1983 [3] M. Tada, Y. Takahama, K. Abe, N. Nakatsuji and T. Tada, Current Biology, vol. 11, no. 19, pp. 1553-1558, Oct.2001 [4] Y. Kimura, M. Gel, B. Techaumnat, H. Oana, H. Kotera and M. Washizu, Electrophoresis, vol. 32, no. 18, pp. 2496-2501, Sep.2011. [5] N. Sasaki, J. S. Gong, M. Sakuragi, K. Hosokawa, M. Maeda and Y. Ito, Japanese Journal of Applied Physics, vol. 51, no. 3, pp. 030206.1-030206.3, Mar. 2012 [6] K. Wada, K. Itoga, T. Okano, S. Yonemura and H. Sasaki, Development, vol. 138, no. 18, pp. 3907-3914, Sep.2011 CONTACT *K.
Recommended publications
  • Cell Fusion Induced by Pederine
    Pediat. Res. 8: 606-608 (1974) Cell fusion heterokaryon pederine Cell Fusion Induced by Pederine MAURAR. LEVINE,[~~]JOSEPH DANCIS,MARIO PAVAN, AND RODYP. COX Division of Human Genetics and the Departments of Pharmacology, Pediatrics and Medicine, New York University School of Medicine, New York, New York, USA, and the Institute of Entomology, University of Pavia, Pavia, Italy Extract Pederine, a natural product extracted from beetles, induces cell fusion among hu- man skin fibroblasts grown in tissue culture. Heterokaryons are produced when pederine is added to mixtures of human diploid fibroblasts and HeLa cells. The effi- ciency of cell fusion exceeds that achieved with other available agents. The technique is simple and the results are reproducible. Cells exposed to pederine under conditions that cause fusion retain their growth potential, which indicates that the treatment does not damage the cells. The technique should prove useful in research into mecha- nisms of membrane fusion, as well as research in which cell fusion is used as an in- vestigative tool. Speculation Lysolecithin is believed to induce cell fusion by perturbing the molecular structure of cellular membranes. Pederine is more effective at concentrations less than one thous- andth that of lysolecithin. The mechanism of pederine-induced cell fusion may pro- vide insight into the physiologic processes which maintain membrane integrity. Introduction years. The phenomenon of membrane fuslon is involved in a multitude of physiological processes including fertilization, pinocytosis and the forma- The experimental induction of cell Yusion among cells grown in tissue culture tion of syncytia. It is also a cmon event in pathological conditions such has facilitated studies of the mechanism of membrane fusion as well as re- as viral Infections and the response to foreign bodies.
    [Show full text]
  • Prokaryotic Sex: Eukaryote-Like Qualities of Recombination in An
    Dispatch R601 Prokaryotic Sex: Eukaryote-like match, the ends may be cut to a random extent by exonucleases, Qualities of Recombination in an and then the newly revealed ends are tested, and so on. This would increase Archaean Lineage the probability that eventually a reduced donor segment would sufficiently match a sequence from the Genetic exchange within one Archaean lineage is a bit like sex in recipient. We suggest this process eukaryotes — cells fuse and huge segments of DNA are recombined — with would be particularly successful in consequences for the spread of adaptations across species. organisms that recombine through cell fusion, as the donor segments start out Frederick M. Cohan* (which may be harmful to the recipient) exceptionally long. This hypothesis and Stephanie Aracena [3]. We therefore hypothesize that predicts that more-closely-related in Haloferax and other cell-fusion organisms may recombine after Two decades ago, Moshe Mevarech systems, niche-transcending a smaller number of cuts; so and colleagues discovered an adaptations may not transfer as easily more-distant crosses would yield extraordinary mode of recombination as in the Bacteria. On the other hand, shorter recombinant segments, in an Archaean taxon — cells of the huge size of recombined a pattern observed in Bacillus Haloferax can recombine through cell segments may foster the transfer transformation [3]. fusion [1]. After two cells fuse, their of extremely complex adaptations The authors suggest that horizontal genomes can recombine, and then the that could not otherwise be transferred genetic transfer would be particularly fused cell can resolve into two cells, [4], including possibly the ancient easy between species where cell fusion each with a single chromosome.
    [Show full text]
  • An Overview of Molecular Events Occurring in Human Trophoblast Fusion Pascale Gerbaud, Guillaume Pidoux
    An overview of molecular events occurring in human trophoblast fusion Pascale Gerbaud, Guillaume Pidoux To cite this version: Pascale Gerbaud, Guillaume Pidoux. An overview of molecular events occurring in human trophoblast fusion. Placenta, Elsevier, 2015, 36 (Suppl1), pp.S35-42. 10.1016/j.placenta.2014.12.015. inserm- 02556112v2 HAL Id: inserm-02556112 https://www.hal.inserm.fr/inserm-02556112v2 Submitted on 28 Apr 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. 1 An overview of molecular events occurring in human trophoblast fusion 2 3 Pascale Gerbaud1,2 & Guillaume Pidoux1,2,† 4 1INSERM, U1139, Paris, F-75006 France; 2Université Paris Descartes, Paris F-75006; France 5 6 Running title: Trophoblast cell fusion 7 Key words: Human trophoblast, Cell fusion, Syncytins, Connexin 43, Cadherin, ZO-1, 8 cAMP-PKA signaling 9 10 Word count: 4276 11 12 13 †Corresponding author: Guillaume Pidoux, PhD 14 Inserm UMR-S-1139 15 Université Paris Descartes 16 Faculté de Pharmacie 17 Cell-Fusion group 18 75006 Paris, France 19 Tel: +33 1 53 73 96 02 20 Fax: +33 1 44 07 39 92 21 E-mail: [email protected] 22 1 23 Abstract 24 During human placentation, mononuclear cytotrophoblasts fuse to form a multinucleated syncytia 25 ensuring hormonal production and nutrient exchanges between the maternal and fetal circulation.
    [Show full text]
  • Review Cell Fusion and Some Subcellular Properties Of
    REVIEW CELL FUSION AND SOME SUBCELLULAR PROPERTIES OF HETEROKARYONS AND HYBRIDS SAIMON GORDON From the Genetics Laboratory, Department of Biochemistry, The University of Oxford, England, and The Rockefeller University, New York 10021 I. INTRODUCTION The technique of somatic cell fusion has made it first cell hybrids obtained by this method. The iso- possible to study cell biology in an unusual and lation of hybrid cells from such mixed cultures direct way. When cells are mixed in the presence of was greatly facilitated by the Szybalski et al. (6) Sendai virus, their membranes coalesce, the cyto- and Littlefield (7, 8) adaptation of a selective me- plasm becomes intermingled, and multinucleated dium containing hypoxanthine, aminopterin, and homo- and heterokaryons are formed by fusion of thymidine (HAT) to mammalian systems. similar or different cells, respectively (1, 2). By Further progress followed the use of Sendai fusing cells which contrast in some important virus by Harris and Watkins to increase the biologic property, it becomes possible to ask ques- frequency of heterokaryon formation (9). These tions about dominance of control processes, nu- authors exploited the observation by Okada that cleocytoplasmic interactions, and complementa- UV irradiation could be used to inactivate Sendai tion in somatic cell heterokaryons. The multinucle- virus without loss of fusion efficiency (10). It was ate cell may divide and give rise to mononuclear therefore possible to eliminate the problem of virus cells containing chromosomes from both parental replication in fused cells. Since many cells carry cells and become established as a hybrid cell line receptors for Sendai virus, including those of able to propagate indefinitely in vitro.
    [Show full text]
  • Structural Insights Into Membrane Fusion Mediated by Convergent Small Fusogens
    cells Review Structural Insights into Membrane Fusion Mediated by Convergent Small Fusogens Yiming Yang * and Nandini Nagarajan Margam Department of Microbiology and Immunology, Dalhousie University, Halifax, NS B3H 4R2, Canada; [email protected] * Correspondence: [email protected] Abstract: From lifeless viral particles to complex multicellular organisms, membrane fusion is inarguably the important fundamental biological phenomena. Sitting at the heart of membrane fusion are protein mediators known as fusogens. Despite the extensive functional and structural characterization of these proteins in recent years, scientists are still grappling with the fundamental mechanisms underlying membrane fusion. From an evolutionary perspective, fusogens follow divergent evolutionary principles in that they are functionally independent and do not share any sequence identity; however, they possess structural similarity, raising the possibility that membrane fusion is mediated by essential motifs ubiquitous to all. In this review, we particularly emphasize structural characteristics of small-molecular-weight fusogens in the hope of uncovering the most fundamental aspects mediating membrane–membrane interactions. By identifying and elucidating fusion-dependent functional domains, this review paves the way for future research exploring novel fusogens in health and disease. Keywords: fusogen; SNARE; FAST; atlastin; spanin; myomaker; myomerger; membrane fusion 1. Introduction Citation: Yang, Y.; Margam, N.N. Structural Insights into Membrane Membrane fusion
    [Show full text]
  • Cell Fusion* Benjamin Podbilewicz1,2, §
    Cell fusion* Benjamin Podbilewicz1,2, § 1 Department of Biology, Technion-Israel, Institute of Technology, Haifa 32000, Israel 2Section on Membrane Biology, Laboratory of Cellular and Molecular Biophysics, NICHD, NIH, Bethesda MD 20892, USA Table of Contents 1. Introduction ............................................................................................................................2 1.1. Ubiquitous cell fusion .................................................................................................... 2 1.2. Cell-to-cell fusion in worms ............................................................................................ 2 1.3. Humans and some nematodes have cellular skin but C. elegans has syncytia ............................. 3 2. Cell biology of plasma membrane fusion ...................................................................................... 5 3. Genetics of cell fusion .............................................................................................................. 7 4. eff-1 is necessary for most, but not all, cell fusion events in C. elegans ..............................................7 5. Regulation of cell fusion ........................................................................................................... 9 5.1. Transcriptional regulation of cell fusion ............................................................................. 9 5.2. Ventral cell fusions .....................................................................................................
    [Show full text]
  • CHAPTER 11 Lipid Acrobatics in the Membrane Fusion Arena
    CHAPTER 11 Lipid Acrobatics in the Membrane Fusion Arena Albert J. Markvoort1 and Siewert J. Marrink2 1Institute for Complex Molecular Systems & Biomodeling and Bioinformatics Group, Eindhoven University of Technology, Eindhoven, The Netherlands 2Groningen Biomolecular Sciences and Biotechnology Institute & Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands I. Overview II. Introduction III. Historical Background IV. Fusion Pathways at the Molecular Level A. Symmetric Stalk Expansion Pathway B. Alternative Pathways C. Composition Dependence V. Energy Landscape Along the Fusion Pathway A. Stalk and Hemifusion Diaphragm Intermediates B. Lipid Splaying as First Step C. Many Barriers to Cross VI. Fission Pathways in Molecular Detail A. Budding/Neck Formation B. Fission not Just Fusion Reversed VII. Peptide Modulated Fusion A. The Role of Fusion Peptides B. Protein-Induced Fusion VIII. Outlook References I. OVERVIEW In this review, we describe the recent contribution of computer simulation approaches to unravel the molecular details of membrane fusion. Over the past decade, fusion between apposed membranes and vesicles has been studied using a large variety of simulation methods and systems. Despite the variety in techniques, some generic fusion pathways emerge that predict a more complex Current Topics in Membranes, Volume 68 0065-230X/10 $35.00 Copyright 2011, Elsevier Inc. All right reserved. DOI: 10.1016/B978-0-12-385891-7.00011-8 260 Markvoort and Marrink picture beyond the traditional stalk–pore pathway. Indeed the traditional path- way is confirmed in particle-based simulations, but in addition alternative path- ways are observed in which stalks expand linearly rather than radially, leading to inverted-micellar or asymmetric hemifusion intermediates.
    [Show full text]
  • Mechanism of Membrane Fusion Induced by Vesicular Stomatitis Virus G Protein
    Mechanism of membrane fusion induced by vesicular stomatitis virus G protein Irene S. Kima,1, Simon Jennia, Megan L. Staniferb,2, Eatai Rothc, Sean P. J. Whelanb, Antoine M. van Oijena,3, and Stephen C. Harrisona,d,4 aDepartment of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115; bDepartment of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115; cDepartment of Biology, University of Washington, Seattle, WA 98195; and dHoward Hughes Medical Institute, Harvard Medical School and Boston Children’s Hospital, Boston, MA 02115 Contributed by Stephen C. Harrison, November 17, 2016 (sent for review October 10, 2016; reviewed by Axel T. Brunger and Frederick M. Hughson) The glycoproteins (G proteins) of vesicular stomatitis virus (VSV) genic conformational changes deviate from the canonical and related rhabdoviruses (e.g., rabies virus) mediate both cell sequence outlined in the preceding paragraph by the absence of attachment and membrane fusion. The reversibility of their fuso- an irreversible priming step and hence the absence of a meta- genic conformational transitions differentiates them from many stable prefusion state. The transition from prefusion conforma- other low-pH-induced viral fusion proteins. We report single-virion tion to extended intermediate is reversible (9, 10). Nonetheless, fusion experiments, using methods developed in previous publica- structures of G in its pre- and postfusion trimeric conformations tions to probe fusion of influenza and West Nile viruses. We show suggest that most of the fusion reaction follows a familiar pat- that a three-stage model fits VSV single-particle fusion kinetics: tern, as illustrated in Fig. 1 (3, 11–13).
    [Show full text]
  • Horizontal Gene Transfers and Cell Fusions in Microbiology, Immunology and Oncology (Review)
    441-465.qxd 20/7/2009 08:23 Ì ™ÂÏ›‰·441 INTERNATIONAL JOURNAL OF ONCOLOGY 35: 441-465, 2009 441 Horizontal gene transfers and cell fusions in microbiology, immunology and oncology (Review) JOSEPH G. SINKOVICS St. Joseph's Hospital's Cancer Institute Affiliated with the H. L. Moffitt Comprehensive Cancer Center; Departments of Medical Microbiology/Immunology and Molecular Medicine, The University of South Florida College of Medicine, Tampa, FL 33607-6307, USA Received April 17, 2009; Accepted June 4, 2009 DOI: 10.3892/ijo_00000357 Abstract. Evolving young genomes of archaea, prokaryota or immunogenic genetic materials. Naturally formed hybrids and unicellular eukaryota were wide open for the acceptance of dendritic and tumor cells are often tolerogenic, whereas of alien genomic sequences, which they often preserved laboratory products of these unisons may be immunogenic in and vertically transferred to their descendants throughout the hosts of origin. As human breast cancer stem cells are three billion years of evolution. Established complex large induced by a treacherous class of CD8+ T cells to undergo genomes, although seeded with ancestral retroelements, have epithelial to mesenchymal (ETM) transition and to yield to come to regulate strictly their integrity. However, intruding malignant transformation by the omnipresent proto-ocogenes retroelements, especially the descendents of Ty3/Gypsy, (for example, the ras oncogenes), they become defenseless the chromoviruses, continue to find their ways into even the toward oncolytic viruses. Cell fusions and horizontal exchanges most established genomes. The simian and hominoid-Homo of genes are fundamental attributes and inherent characteristics genomes preserved and accommodated a large number of of the living matter.
    [Show full text]
  • Glossary of Biotechnology Terms
    GLOSSARY OF BIOTECHNOLOGY TERMS Until recently, command of technical terms among lawyers was largely limited to patent counsel. Now, with the dramatic increase in the interaction between technology and law, there is a generalized need among lawyers for greater agility and familiarity with scientific jargon. This glossary has been compiled as a checklist of common biotechnology terms to aid the scientifically uninitiated practitioner. Special attention has been paid to terms which appear in the accompanying articles by Bertram I. Rowland1 and Adrienne B. Naumann. 2 No attempt, however, has been made to provide a comprehensive biotechnology dictionary. For further technical guidance, please see the accompanying Research 3 Pathfinder. Amino acid - Any Organic com- vaccines, blood, blood components pound containing both an amino and derivatives, or allergenic pro- group and a carboxylic group, bound ducts. as essential components of a protein Biotechnology - Commercial tech- molecule. niques that use living organisms, or Antenatal diagnosis - Diagnosis of substances from these organisms, to a condition before birth. make or modify a product, and Antibody - A protein produced by including techniques used for the the body's immune defense system improvement of the characteristics of that can bind to foreign molecules economically important plants and and eliminate them. animals and for the development of Bacterium - Single-celled organism microorganisms to act on the lacking a nucleus and other struc- environment. tures; useful for cloning genes Cell - The fundamental unit of liv- because of fast growth. Bacteria may ing organisms. The cell is character- exist as free living organisms in soil, ized by an outer wall or membrane water, organic matter, or as parasites which is selectively permeable to in the live bodies of plants, animals nutrients, water, and other com- and other microorganisms.
    [Show full text]
  • Virus-Mediated Cell-Cell Fusion
    International Journal of Molecular Sciences Review Virus-Mediated Cell-Cell Fusion Héloïse Leroy 1,2,3, Mingyu Han 1,2,3 , Marie Woottum 1,2,3 , Lucie Bracq 4 , Jérôme Bouchet 5 , Maorong Xie 6 and Serge Benichou 1,2,3,* 1 Institut Cochin, Inserm U1016, 75014 Paris, France; [email protected] (H.L.); [email protected] (M.H.); [email protected] (M.W.) 2 Centre National de la Recherche Scientifique CNRS, UMR8104, 75014 Paris, France 3 Faculty of Health, University of Paris, 75014 Paris, France 4 Global Health Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; lucie.bracq@epfl.ch 5 Laboratory Orofacial Pathologies, Imaging and Biotherapies UR2496, University of Paris, 92120 Montrouge, France; [email protected] 6 Division of Infection and Immunity, University College London, London WC1E 6BT, UK; [email protected] * Correspondence: [email protected] Received: 20 November 2020; Accepted: 14 December 2020; Published: 17 December 2020 Abstract: Cell-cell fusion between eukaryotic cells is a general process involved in many physiological and pathological conditions, including infections by bacteria, parasites, and viruses. As obligate intracellular pathogens, viruses use intracellular machineries and pathways for efficient replication in their host target cells. Interestingly, certain viruses, and, more especially, enveloped viruses belonging to different viral families and including human pathogens, can mediate cell-cell fusion between infected cells and neighboring non-infected cells. Depending of the cellular environment and tissue organization, this virus-mediated cell-cell fusion leads to the merge of membrane and cytoplasm contents and formation of multinucleated cells, also called syncytia, that can express high amount of viral antigens in tissues and organs of infected hosts.
    [Show full text]
  • Fusion As the Result of Sperm–Somatic Cell Interaction
    REPRODUCTIONRESEARCH Fusion as the result of sperm–somatic cell interaction M Mattioli, A Gloria, A Mauro, L Gioia and B Barboni Department of Comparative Biomedical Sciences, University of Teramo, Piazza A. Moro, 45, 64100 Teramo, Italy Correspondence should be addressed to A Gloria; Email: [email protected] B Barboni; Email: [email protected] Abstract The research has been designed to investigate whether acrosome-reacted spermatozoa can fuse with somatic cells and to check whether this event may involve the molecular machinery implicated in the sperm–egg fusion. Boar spermatozoa were capacitated in vitro and then treated with A23187 to induce acrosome reaction and activate their fusogenic potential. Reacted spermatozoa, loaded with the membrane-permeant fluorescent dye calcein AM, were incubated with plated granulosa cells or cells derived from stable cell lines: CRFK, VERO, and ESK4. The fusion between spermatozoa and somatic cells was revealed by the diffusion of the fluorescent dye from the sperm to the cell as membrane fusion and cytoplasmic continuity between the two cells were established. The involvement of integrin a6 and tetraspanin CD9 in the process of fusion was assessed by carrying out the experiment in the presence of antibodies against these molecules. Moreover, the incidence of fusion displayed by the different cell types used was analyzed in relation to their content in the above molecules assessed by western blot and immunostaining. The role of CD9 was additionally investigated by using CD9-negative cells. The data presented demonstrate that boar spermatozoa can fuse with different somatic cell types derived from different species and the process requires the combined presence of both integrin and tetraspanin molecules on the cell plasma membrane.
    [Show full text]