239 MAC-T CELLS AS A TOOL TO EXAMINE GENOME EDITING USING CLUSTERED REGULARLY INTERSPACED SHORT PALINDROMIC REPEATS (CRISPR)

2016 ◽  
Vol 28 (2) ◽  
pp. 251
Author(s):  
S. N. Lotti ◽  
I. Tasan ◽  
H. Zhao ◽  
M. B. Wheeler
Keyword(s):  
T Cells ◽  
Milk Production ◽  
Fluorescent Protein ◽  
The United States ◽  
The Other ◽  
Total Efficiency ◽  
Guide Rnas ◽  
Exon 1 ◽  
Green Fluorescent ◽  
A Site

In 2050, the expected size of the human population is 9 billion, the demand for food will increase, and the demand for milk will increase along with it. Genetically modifying animals is a tool that can be used to meet this growing demand. In the United States, Holstein is the leading breed for milk production and Holsteins produce on average 24 291 pounds of milk per year, whereas Jerseys, the other major dairy breed, produce on average 16 997 pounds. Their ability to produce large quantities of milk is linked to 2 mutations. These mutations are on the α-lactalbumin (α-lac) gene; the α-lac exon (+1) corresponds to the transcription start point of α-lac, (+15) and (–1689) are the positions corresponding to the single nucleotide polymorphism associated with increased milk production. Holstein cows have an adenine at both of these positions in contrast to the other cattle breeds with lower milk production, which have either a cytosine or guanine at either position. Inserting an adenine at position (+15) and (–1689) in cows without this mutation could lead to increased milk production and a better response to market demands. The purpose of this experiment was to test the cutting efficiency of candidate clustered regularly interspaced short palindromic repeats (CRISPR) that will later be used in knock-in experiments. CRISPRs were used because the CRISPR-Cas9 system is inexpensive, easily programmed, and efficient. In this preliminary study, we worked with Holstein MAC-T cells, which already contain the mutation at both positions. CRISPRs were used on this cell line to cut the DNA at a site near the mutation. Based on the genomic DNA sequence of these MAC-T cells, 3 guide RNAs were designed. Cells were then transfected with the designed CRISPRs by a variety of transfection methods, including Fugene™ (Promega, Madison, WI, USA), electroporation, and Lipofectamine (ThermoFisher Scientific, Waltham, MA, USA). Green fluorescent protein was used to determine the efficiency of transfection; 30% efficiency was seen for Fugene™, whereas electroporation and Lipofectamine™ had 70% efficiency. To select for successfully transfected cells, puromycin selection was applied. The DNA was later extracted and sent in for sequencing. Next, the website TIDE was used to compare the transfected MAC-T cells to normal MAC-T cells. The TIDE software measures the editing efficiency and looks for major insertions or deletions in pools of DNA by comparing 2 sequences to quantify the editing efficacy of CRISPR-Cas9. Our results showed that CRISPRs successfully cut the DNA near the α-lac mutation region with a total efficiency of 13.8%. The desired next step will be to insert a single-strand oligonucleotide (ssODN) donor to make a single basepair mutation. The ultimate aim of this research would be to insert these mutations into other cattle species in order to increase their milk production.

scholarly journals Sec1p Binds to SNARE Complexes and Concentrates at Sites of Secretion

1999 ◽  
Vol 146 (2) ◽  
pp. 333-344 ◽  
Author(s):  
Chavela M. Carr ◽  
Eric Grote ◽  
Mary Munson ◽  
Frederick M. Hughson ◽  
Peter J. Novick
Keyword(s):  
Fluorescent Protein ◽  
Snare Complex ◽  
The Other ◽  
Complex Assembly ◽  
Vesicle Docking ◽  
Neuronal Protein ◽  
The Core ◽  
Target Membrane ◽  
Green Fluorescent ◽  
And Function

Proteins of the Sec1 family have been shown to interact with target-membrane t-SNAREs that are homologous to the neuronal protein syntaxin. We demonstrate that yeast Sec1p coprecipitates not only the syntaxin homologue Ssop, but also the other two exocytic SNAREs (Sec9p and Sncp) in amounts and in proportions characteristic of SNARE complexes in yeast lysates. The interaction between Sec1p and Ssop is limited by the abundance of SNARE complexes present in sec mutants that are defective in either SNARE complex assembly or disassembly. Furthermore, the localization of green fluorescent protein (GFP)-tagged Sec1p coincides with sites of vesicle docking and fusion where SNARE complexes are believed to assemble and function. The proposal that SNARE complexes act as receptors for Sec1p is supported by the mislocalization of GFP-Sec1p in a mutant defective for SNARE complex assembly and by the robust localization of GFP-Sec1p in a mutant that fails to disassemble SNARE complexes. The results presented here place yeast Sec1p at the core of the exocytic fusion machinery, bound to SNARE complexes and localized to sites of secretion.

Dynamic localization of penicillin-binding proteins during spore development in Bacillus subtilis

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 999-1012 ◽  
Author(s):  
Dirk-Jan Scheffers
Keyword(s):  
Bacillus Subtilis ◽  
Green Fluorescent Protein ◽  
Binding Proteins ◽  
Cytoplasmic Membrane ◽  
Fluorescent Protein ◽  
Spore Formation ◽  
The Other ◽  
Spore Development ◽  
Penicillin Binding Proteins ◽  
Green Fluorescent

During Bacillus subtilis spore formation, many membrane proteins that function in spore development localize to the prespore septum and, subsequently, to the outer prespore membrane. Recently, it was shown that the cell-division-specific penicillin-binding proteins (PBPs) 1 and 2b localize to the asymmetric prespore septum. Here, the author studied the localization of other PBPs, fused to green fluorescent protein (GFP), during spore formation. Fusions to PBPs 4, 2c, 2d, 2a, 3, H, 4b, 5, 4a, 4* and X were expressed during vegetative growth, and their localization was monitored during sporulation. Of these PBPs, 2c, 2d, 4b and 4* have been implicated as having a function in sporulation. It was found that PBP2c, 2d and X changed their localization, while the other PBPs tested were not affected. The putative endopeptidase PbpX appears to spiral out in a pattern that resembles FtsZ redistribution during sporulation, but a pbpX knockout strain had no distinguishable phenotype. PBP2c and 2d localize to the prespore septum and follow the membrane during engulfment, and so are redistributed to the prespore membrane. A similar pattern was observed when GFP–PBP2c was expressed in the mother cell from a sporulation-specific promoter. This work shows that various PBPs known to function during sporulation are redistributed from the cytoplasmic membrane to the prespore.

scholarly journals Changes in the Min Oscillation Pattern before and after Cell Birth

2010 ◽  
Vol 192 (16) ◽  
pp. 4134-4142 ◽  
Author(s):  
Jennifer R. Juarez ◽  
William Margolin
Keyword(s):  
Cell Division ◽  
Fluorescent Protein ◽  
Time Lapse ◽  
The Other ◽  
Cell Pole ◽  
Daughter Cells ◽  
Division Site ◽  
Before And After ◽  
Dividing Cells ◽  
Green Fluorescent

ABSTRACT The Min system regulates the positioning of the cell division site in many bacteria. In Escherichia coli, MinD migrates rapidly from one cell pole to the other. In conjunction with MinC, MinD helps to prevent unwanted FtsZ rings from assembling at the poles and to stabilize their positioning at midcell. Using time-lapse microscopy of growing and dividing cells expressing a gfp-minD fusion, we show that green fluorescent protein (GFP)-MinD often paused at midcell in addition to at the poles, and the frequency of midcell pausing increased as cells grew longer and cell division approached. At later stages of septum formation, GFP-MinD often paused specifically on only one side of the septum, followed by migration to the other side of the septum or to a cell pole. About the time of septum closure, this irregular pattern often switched to a transient double pole-to-pole oscillation in the daughter cells, which ultimately became a stable double oscillation. The splitting of a single MinD zone into two depends on the developing septum and is a potential mechanism to explain how MinD is distributed equitably to both daughter cells. Septal pausing of GFP-MinD did not require MinC, suggesting that MinC-FtsZ interactions do not drive MinD-septal interactions, and instead MinD recognizes a specific geometric, lipid, and/or protein target at the developing septum. Finally, we observed regular end-to-end oscillation over very short distances along the long axes of minicells, supporting the importance of geometry in MinD localization.

scholarly journals Generation of a Recombinant Cytomegalovirus for Expression of a Hantavirus Glycoprotein

2003 ◽  
Vol 77 (22) ◽  
pp. 12203-12210 ◽  
Author(s):  
Albert A. Rizvanov ◽  
Albert G. M. van Geelen ◽  
Sergey Morzunov ◽  
Elmer W. Otteson ◽  
Charlotte Bohlman ◽  
...  
Keyword(s):  
Recombinant Virus ◽  
Fluorescent Protein ◽  
Deer Mice ◽  
Anamnestic Response ◽  
Egfp Gene ◽  
Virus Challenge ◽  
Virus Particles ◽  
Green Fluorescent ◽  
Human Cmv ◽  
A Site

ABSTRACT A cytomegalovirus (CMV) was isolated from its natural host, Peromyscus maniculatus, and was designated Peromyscus CMV (PCMV). A recombinant PCMV was constructed that contained Sin Nombre virus glycoprotein G1 (SNV-G1) fused in frame to the enhanced green fluorescent protein (EGFP) gene inserted into a site homologous to the human CMV UL33 (P33) gene. The recombinant CMV was used for expression and immunization of deer mice against SNV-G1. The results of the study indicate that P. maniculatus could be infected with as few as 10 virus particles of recombinant virus. Challenge of P. maniculatus with either recombinant or wild-type PCMV produced no overt pathology in infected animals. P. maniculatus immunized with recombinant virus developed an antibody response to SNV and EGFP. When rechallenged with recombinant virus, animals exhibited an anamnestic response against SNV. Interestingly, a preexisting immune response against PCMV did not prevent reinfection with recombinant PCMV.

scholarly journals Induction of Effective Immunity against Trypanosoma cruzi

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Tere Williams ◽  
Ignacio Guerrero-Ros ◽  
Yanfen Ma ◽  
Fabiane Matos dos Santos ◽  
Philipp E. Scherer ◽  
...  
Keyword(s):  
T Cells ◽  
Trypanosoma Cruzi ◽  
Immune Cells ◽  
Fluorescent Protein ◽  
Rapid Expansion ◽  
Public Health Issue ◽  
Necrosis Factor Alpha ◽  
Content Type ◽  
Ifn Γ ◽  
Green Fluorescent

ABSTRACT Chagas disease, caused by Trypanosoma cruzi, is a major public health issue. Limitations in immune responses to natural T. cruzi infection usually result in parasite persistence with significant complications. A safe, effective, and reliable vaccine would reduce the threat of T. cruzi infections; however, no suitable vaccine is currently available due to a lack of understanding of the requirements for induction of fully protective immunity. We established a T. cruzi strain expressing green fluorescent protein (GFP) under the control of dihydrofolate reductase degradation domain (DDD) with a hemagglutinin (HA) tag, GFP-DDDHA, which was induced by trimethoprim-lactate (TMP-lactate), which results in the death of intracellular parasites. This attenuated strain induces very strong protection against reinfection. Using this GFP-DDDHA strain, we investigated the mechanisms underlying the protective immune response in mice. Immunization with this strain led to a response that included high levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α), as well as a rapid expansion of effector and memory T cells in the spleen. More CD8+ T cells differentiate to memory cells following GFP-DDDHA infection than after infection with a wild-type (WT) strain. The GFP-DDDHA strain also provides cross-protection against another T. cruzi isolate. IFN-γ is important in mediating the protection, as IFN-γ knockout (KO) mice failed to acquire protection when infected with the GFP-DDDHA strain. Immune cells demonstrated earlier and stronger protective responses in immunized mice after reinfection with T. cruzi than those in naive mice. Adoptive transfers with several types of immune cells or with serum revealed that several branches of the immune system mediated protection. A combination of serum and natural killer cells provided the most effective protection against infection in these transfer experiments.

scholarly journals ROLE OF GREEN-FLUORESCENT-PROTEIN-EXPRESSING T CELLS IN EXPERIMENTAL AUTOIMMUNE MYOCARDITIS

2011 ◽  
Vol 57 (14) ◽  
pp. E228
Author(s):  
Tomoyoshi Yanagisawa ◽  
Takayuki Inomata ◽  
Ichiro Watanabe ◽  
Emi Maekawa ◽  
Tomohiro Mizutani ◽  
...  
Keyword(s):  
T Cells ◽  
Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Autoimmune Myocarditis ◽  
Experimental Autoimmune Myocarditis ◽  
Green Fluorescent ◽  
Experimental Autoimmune

scholarly journals Enhancement of Innate and Cell-Mediated Immunity by Antimycobacterial Antibodies

2005 ◽  
Vol 73 (10) ◽  
pp. 6711-6720 ◽  
Author(s):  
S. de Vallière ◽  
G. Abate ◽  
A. Blazevic ◽  
R. M. Heuertz ◽  
D. F. Hoft
Keyword(s):  
T Cells ◽  
Immune Responses ◽  
Fluorescent Protein ◽  
Cell Mediated Immunity ◽  
Phagocytic Cells ◽  
Surface Binding ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Green Fluorescent ◽  
Mycobacterial Growth

ABSTRACT We investigated the ability of human antibodies induced by Mycobacterium bovis bacillus Calmette-Guérin (BCG) vaccination to protect against mycobacterial infections. Serum samples containing mycobacterium-specific antibodies were obtained from volunteers who had received two intradermal BCG vaccinations 6 months apart. Significant increases in lipoarabinomannan (LAM)-specific immunoglobulin G (IgG) were detected after both the primary and booster vaccinations. Effects of mycobacterium-specific antibodies on surface binding and internalization of BCG by neutrophils and monocytes/macrophages were studied, using green fluorescent protein (gfp)-expressing BCG. Surface-bound gfp-expressing BCG were distinguished from intracellular BCG by surface labeling with LAM-specific monoclonal antibody. Internalization of BCG by phagocytic cells was shown to be significantly enhanced in postvaccination serum samples. Furthermore, the inhibitory effects of neutrophils and monocytes/macrophages on mycobacterial growth were significantly enhanced by BCG-induced antibodies. The growth-inhibiting effects of postvaccination sera were reversed by preabsorption of IgG with Protein G. Finally, the helper effects of antimycobacterial antibodies for the induction of cell-mediated immune responses were investigated. BCG-induced antibodies significantly enhanced proliferation and gamma interferon production in mycobacterium-specific CD4+ and CD8+ T cells, as well as the proportion of proliferating and degranulating CD8+ T cells. We conclude that mycobacterium-specific antibodies are capable of enhancing both innate and cell-mediated immune responses to mycobacteria.

scholarly journals Assigning mitochondrial localization of dual localized proteins using a yeast Bi-Genomic Mitochondrial-Split-GFP

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Gaétan Bader ◽  
Ludovic Enkler ◽  
Yuhei Araiso ◽  
Marine Hemmerle ◽  
Krystyna Binko ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Nuclear Gene ◽  
The Self ◽  
The Other ◽  
Green Fluorescent Protein Fusion ◽  
Mitochondrial Localization ◽  
Protein Fusion ◽  
Argonaute 2 ◽  
New Type ◽  
Green Fluorescent

A single nuclear gene can be translated into a dual localized protein that distributes between the cytosol and mitochondria. Accumulating evidences show that mitoproteomes contain lots of these dual localized proteins termed echoforms. Unraveling the existence of mitochondrial echoforms using current GFP (Green Fluorescent Protein) fusion microscopy approaches is extremely difficult because the GFP signal of the cytosolic echoform will almost inevitably mask that of the mitochondrial echoform. We therefore engineered a yeast strain expressing a new type of Split-GFP that we termed Bi-Genomic Mitochondrial-Split-GFP (BiG Mito-Split-GFP). Because one moiety of the GFP is translated from the mitochondrial machinery while the other is fused to the nuclear-encoded protein of interest translated in the cytosol, the self-reassembly of this Bi-Genomic-encoded Split-GFP is confined to mitochondria. We could authenticate the mitochondrial importability of any protein or echoform from yeast, but also from other organisms such as the human Argonaute 2 mitochondrial echoform.

scholarly journals Degradation of SAMHD1 by Vpx Is Independent of Uncoating

2015 ◽  
Vol 89 (10) ◽  
pp. 5701-5713 ◽  
Author(s):  
Paula Jáuregui ◽  
Eric C. Logue ◽  
Megan L. Schultz ◽  
Stephanie Fung ◽  
Nathaniel R. Landau
Keyword(s):  
T Cells ◽  
Green Fluorescent Protein ◽  
Fusion Protein ◽  
Hela Cell ◽  
Nuclear Localization ◽  
Fluorescent Protein ◽  
Nuclear Localization Sequence ◽  
Hela Cell Lines ◽  
Localization Sequence ◽  
Green Fluorescent

ABSTRACTSterile alpha motif domain and HD domain-containing protein 1 (SAMHD1) restricts human immunodeficiency virus type 1 (HIV-1) replication in myeloid and resting T cells. Lentiviruses such as HIV-2 and some simian immunodeficiency viruses (SIVs) counteract the restriction by encoding Vpx or Vpr, accessory proteins that are packaged in virions and which, upon entry of the virus into the cytoplasm, induce the proteasomal degradation of SAMHD1. As a tool to study these mechanisms, we generated HeLa cell lines that express a fusion protein termed NLS.GFP.SAM595 in which the Vpx binding domain of SAMHD1 is fused to the carboxy terminus of green fluorescent protein (GFP) and a nuclear localization signal is fused to the amino terminus of GFP. Upon incubation of Vpx-containing virions with the cells, the NLS.GFP.SAM595 fusion protein was degraded over several hours and the levels remained low over 5 days as the result of continued targeting of the CRL4 E3 ubiquitin ligase. Degradation of the fusion protein required that it contain a nuclear localization sequence. Fusion to the cytoplasmic protein muNS rendered the protein resistant to Vpx-mediated degradation, confirming that SAMHD1 is targeted in the nucleus. Virions treated with protease inhibitors failed to release Vpx, indicating that Gag processing was required for Vpx release from the virion. Mutations in the capsid protein that altered the kinetics of virus uncoating and the Gag binding drug PF74 had no effect on the Vpx-mediated degradation. These results suggest that Vpx is released from virions without a need for uncoating of the capsid, allowing Vpx to transit to the nucleus rapidly upon entry into the cytoplasm.IMPORTANCESAMHD1 restricts lentiviral replication in myeloid cells and resting T cells. Its importance is highlighted by the fact that viruses such as HIV-2 encode an accessory protein that is packaged in the virion and is dedicated to inducing SAMHD1 degradation. Vpx needs to act rapidly upon infection to allow reverse transcription to proceed. The limited number of Vpx molecules in a virion also needs to clear the cell of SAMHD1 over a prolonged period of time. Using an engineered HeLa cell line that expresses a green fluorescent protein (GFP)-SAMHD1 fusion protein, we showed that the Vpx-dependent degradation occurs without a need for viral capsid uncoating. In addition, the fusion protein was degraded only when it was localized to the nucleus, confirming that SAMHD1 is targeted in the nucleus and thus explaining why Vpx also localizes to the nucleus.

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