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Atsuo Ogura - One of the best experts on this subject based on the ideXlab platform.

  • recent advancements in Cloning by somatic Cell nuclear transfer
    Philosophical Transactions of the Royal Society B, 2013
    Co-Authors: Atsuo Ogura, Kimiko Inoue, Teruhiko Wakayama
    Abstract:

    Somatic Cell nuclear transfer (SCNT) Cloning is the sole reproductive engineering technology that endows the somatic Cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic Cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chromatin of the reconstructed embryos. Although it will take a considerable time before we fully understand the nature of genomic programming and totipotency, we may expect that somatic Cell Cloning technology will soon become broadly applicable to practical purposes, including medicine, pharmaceutical manufacturing and agriculture. Here we review recent progress in somatic Cell Cloning, with a special emphasis on epigenetic studies using the laboratory mouse as a model.

  • sex reversed somatic Cell Cloning in the mouse
    Journal of Reproduction and Development, 2009
    Co-Authors: Kimiko Inoue, Atsuo Ogura, Narumi Ogonuki, Kazuyuki Mekada, Atsushi Yoshiki, Takashi Sado
    Abstract:

    Somatic Cell nuclear transfer has many potential applications in the fields of basic and applied sciences. However, it has a disadvantage that can never be overcome technically-the inflexibility of the sex of the offspring. Here, we report an accidental birth of a female mouse following nuclear transfer using an immature Sertoli Cell. We produced a batch of 27 clones in a nuclear transfer experiment using Sertoli Cells collected from neonatal male mice. Among them, one pup was female. This "male-derived female" clone grew into a normal adult and produced offspring by natural mating with a littermate. Chromosomal analysis revealed that the female clone had a 39,X karyotype, indicating that the Y chromosome had been deleted in the donor Cell or at some early step during nuclear transfer. This finding suggests the possibility of resuming sexual reproduction after a single male is cloned, which should be especially useful for reviving extinct or endangered species.

  • effects of donor Cell type and genotype on the efficiency of mouse somatic Cell Cloning
    Biology of Reproduction, 2003
    Co-Authors: Kimiko Inoue, Narumi Ogonuki, Yoshie Yamamoto, Keiji Mochida, Kaoru Takano, Takashi Kohda, Fumitoshi Ishino, Atsuo Ogura
    Abstract:

    Abstract Although it is widely assumed that the Cell type and genotype of the donor Cell affect the efficiency of somatic Cell Cloning, little systematic analysis has been done to verify this assumption. The present study was undertaken to examine whether donor Cell type, donor genotype, or a combination thereof increased the efficiency of mouse Cloning. Initially we assessed the developmental ability of embryos that were cloned from cumulus or immature Sertoli Cells with six different genotypes (i.e., 2 × 6 factorial). Significantly better cleavage rates were obtained with cumulus Cells than with Sertoli Cells (P < 0.005, two-way ANOVA), which probably was due to the superior Cell-cycle synchrony of cumulus Cells at G0/G1. After embryo transfer, there was a significant effect of Cell type on the birth rate, with Sertoli Cells giving the better result (P < 0.005). Furthermore, there was a significant interaction (P < 0.05) between the Cell type and genotype, which indicates that Cloning efficiency is dete...

  • effects of donor Cell type and genotype on the efficiency of mouse somatic Cell Cloning
    Biology of Reproduction, 2003
    Co-Authors: Kimiko Inoue, Narumi Ogonuki, Yoshie Yamamoto, Keiji Mochida, Kaoru Takano, Takashi Kohda, Fumitoshi Ishino, Atsuo Ogura
    Abstract:

    Although it is widely assumed that the Cell type and genotype of the donor Cell affect the efficiency of somatic Cell Cloning, little systematic analysis has been done to verify this assumption. The present study was undertaken to examine whether donor Cell type, donor genotype, or a combination thereof increased the efficiency of mouse Cloning. Initially we assessed the developmental ability of embryos that were cloned from cumulus or immature Sertoli Cells with six different genotypes (i.e., 2 x 6 factorial). Significantly better cleavage rates were obtained with cumulus Cells than with Sertoli Cells (P < 0.005, two-way ANOVA), which probably was due to the superior Cell-cycle synchrony of cumulus Cells at G0/G1. After embryo transfer, there was a significant effect of Cell type on the birth rate, with Sertoli Cells giving the better result (P < 0.005). Furthermore, there was a significant interaction (P < 0.05) between the Cell type and genotype, which indicates that Cloning efficiency is determined by a combination of these two factors. The highest mean birth rate (10.8 +/- 2.1%) was obtained with (B6 x 129)F1 Sertoli Cells. In the second series of experiments, we examined whether the developmental ability of clones with the wild-type genotype (JF1) was improved when combined with the 129 genotype. Normal pups were cloned from cumulus and immature Sertoli Cells of the (129 x JF1)F1 and (JF1 x 129)F1 genotypes, whereas no pups were born from Cells with the (B6 x JF1)F1 genotype. The present study clearly demonstrates that the efficiency of somatic Cell Cloning, and in particular fetal survival after embryo transfer, may be improved significantly by choosing the appropriate combinations of Cell type and genotype.

  • phenotypic effects of somatic Cell Cloning in the mouse
    Cloning and Stem Cells, 2002
    Co-Authors: Atsuo Ogura, Kimiko Inoue, Narumi Ogonuki, Takashi Kohda, J Lee, Fumitoshi Ishino
    Abstract:

    Although a variety of phenotypes and epigenetic alterations have been reported in animals cloned from somatic Cells, the exact nature and consequences of Cloning remain unclear. We cloned mice using fresh or short-term cultures of donor Cells (cumulus Cells, immature Sertoli Cells, and fetal or adult fibroblast Cells) with defined genetic backgrounds, and then compared the phenotypic and epigenetic characteristics of the cloned mice with those of fertilization-derived control mice. Irrespective of the nucleus-donor Cell type, about 50% of the reconstructed embryos developed to the morula/blastocyst stage, but about 90% of these clones showed arrested development between days 5 and 8, shortly after implantation. Most of the clones were alive at term, readily recovered respiration, and did not show any malformations or overgrowths. However, their placentas were two- to threefold larger than those of the controls, due to hyperplasia of the basal (or spongiotrophoblast) layer. Although there was significant s...

Luca Quagliata - One of the best experts on this subject based on the ideXlab platform.

  • parallel t Cell Cloning and deep sequencing of human mait Cells reveal stable oligoclonal tcrβ repertoire
    Nature Communications, 2014
    Co-Authors: Marco Lepore, Artem Kalinicenko, Alessia Colone, Bhairav Paleja, Amit Singhal, Andreas Tschumi, Michael Poidinger, Francesca Zolezzi, Luca Quagliata, Peter Sander
    Abstract:

    Mucosal-associated invariant T (MAIT) Cells are a subset of innate-like T Cells, abundant in mucosal tissues, blood and liver. Here, using T-Cell Cloning and deep sequencing, Lepore et al. analyse the T-Cell receptorβ repertoire of MAIT Cells and further characterize function and tissue distribution of two semi-invariant subsets of these Cells.

  • parallel t Cell Cloning and deep sequencing of human mait Cells reveal stable oligoclonal tcrβ repertoire
    Nature Communications, 2014
    Co-Authors: Marco Lepore, Artem Kalinicenko, Alessia Colone, Bhairav Paleja, Amit Singhal, Andreas Tschumi, Michael Poidinger, Francesca Zolezzi, Bernett Lee, Luca Quagliata
    Abstract:

    Mucosal-associated invariant T (MAIT) Cells are abundant in humans and recognize conserved bacterial antigens derived from riboflavin precursors, presented by the non-polymorphic MHC class I-like molecule MR1. Here we show that human MAIT Cells are remarkably oligoclonal in both the blood and liver, display high inter-individual homology and exhibit a restricted length CDR3β domain of the TCRVβ chain. We extend this analysis to a second sub-population of MAIT Cells expressing a semi-invariant TCR conserved between individuals. Similar to 'conventional' MAIT Cells, these lymphocytes react to riboflavin-synthesizing microbes in an MR1-restricted manner and infiltrate solid tissues. Both MAIT Cell types release Th0, Th1 and Th2 cytokines, and sCD40L in response to bacterial infection, show cytotoxic capacity against infected Cells and promote killing of intraCellular bacteria, thus suggesting important protective and immunoregulatory functions of these lymphocytes.

Marco Lepore - One of the best experts on this subject based on the ideXlab platform.

  • parallel t Cell Cloning and deep sequencing of human mait Cells reveal stable oligoclonal tcrβ repertoire
    Nature Communications, 2014
    Co-Authors: Marco Lepore, Artem Kalinicenko, Alessia Colone, Bhairav Paleja, Amit Singhal, Andreas Tschumi, Michael Poidinger, Francesca Zolezzi, Luca Quagliata, Peter Sander
    Abstract:

    Mucosal-associated invariant T (MAIT) Cells are a subset of innate-like T Cells, abundant in mucosal tissues, blood and liver. Here, using T-Cell Cloning and deep sequencing, Lepore et al. analyse the T-Cell receptorβ repertoire of MAIT Cells and further characterize function and tissue distribution of two semi-invariant subsets of these Cells.

  • parallel t Cell Cloning and deep sequencing of human mait Cells reveal stable oligoclonal tcrβ repertoire
    Nature Communications, 2014
    Co-Authors: Marco Lepore, Artem Kalinicenko, Alessia Colone, Bhairav Paleja, Amit Singhal, Andreas Tschumi, Michael Poidinger, Francesca Zolezzi, Bernett Lee, Luca Quagliata
    Abstract:

    Mucosal-associated invariant T (MAIT) Cells are abundant in humans and recognize conserved bacterial antigens derived from riboflavin precursors, presented by the non-polymorphic MHC class I-like molecule MR1. Here we show that human MAIT Cells are remarkably oligoclonal in both the blood and liver, display high inter-individual homology and exhibit a restricted length CDR3β domain of the TCRVβ chain. We extend this analysis to a second sub-population of MAIT Cells expressing a semi-invariant TCR conserved between individuals. Similar to 'conventional' MAIT Cells, these lymphocytes react to riboflavin-synthesizing microbes in an MR1-restricted manner and infiltrate solid tissues. Both MAIT Cell types release Th0, Th1 and Th2 cytokines, and sCD40L in response to bacterial infection, show cytotoxic capacity against infected Cells and promote killing of intraCellular bacteria, thus suggesting important protective and immunoregulatory functions of these lymphocytes.

Kimiko Inoue - One of the best experts on this subject based on the ideXlab platform.

  • recent advancements in Cloning by somatic Cell nuclear transfer
    Philosophical Transactions of the Royal Society B, 2013
    Co-Authors: Atsuo Ogura, Kimiko Inoue, Teruhiko Wakayama
    Abstract:

    Somatic Cell nuclear transfer (SCNT) Cloning is the sole reproductive engineering technology that endows the somatic Cell genome with totipotency. Since the first report on the birth of a cloned sheep from adult somatic Cells in 1997, many technical improvements in SCNT have been made by using different epigenetic approaches, including enhancement of the levels of histone acetylation in the chromatin of the reconstructed embryos. Although it will take a considerable time before we fully understand the nature of genomic programming and totipotency, we may expect that somatic Cell Cloning technology will soon become broadly applicable to practical purposes, including medicine, pharmaceutical manufacturing and agriculture. Here we review recent progress in somatic Cell Cloning, with a special emphasis on epigenetic studies using the laboratory mouse as a model.

  • sex reversed somatic Cell Cloning in the mouse
    Journal of Reproduction and Development, 2009
    Co-Authors: Kimiko Inoue, Atsuo Ogura, Narumi Ogonuki, Kazuyuki Mekada, Atsushi Yoshiki, Takashi Sado
    Abstract:

    Somatic Cell nuclear transfer has many potential applications in the fields of basic and applied sciences. However, it has a disadvantage that can never be overcome technically-the inflexibility of the sex of the offspring. Here, we report an accidental birth of a female mouse following nuclear transfer using an immature Sertoli Cell. We produced a batch of 27 clones in a nuclear transfer experiment using Sertoli Cells collected from neonatal male mice. Among them, one pup was female. This "male-derived female" clone grew into a normal adult and produced offspring by natural mating with a littermate. Chromosomal analysis revealed that the female clone had a 39,X karyotype, indicating that the Y chromosome had been deleted in the donor Cell or at some early step during nuclear transfer. This finding suggests the possibility of resuming sexual reproduction after a single male is cloned, which should be especially useful for reviving extinct or endangered species.

  • effects of donor Cell type and genotype on the efficiency of mouse somatic Cell Cloning
    Biology of Reproduction, 2003
    Co-Authors: Kimiko Inoue, Narumi Ogonuki, Yoshie Yamamoto, Keiji Mochida, Kaoru Takano, Takashi Kohda, Fumitoshi Ishino, Atsuo Ogura
    Abstract:

    Abstract Although it is widely assumed that the Cell type and genotype of the donor Cell affect the efficiency of somatic Cell Cloning, little systematic analysis has been done to verify this assumption. The present study was undertaken to examine whether donor Cell type, donor genotype, or a combination thereof increased the efficiency of mouse Cloning. Initially we assessed the developmental ability of embryos that were cloned from cumulus or immature Sertoli Cells with six different genotypes (i.e., 2 × 6 factorial). Significantly better cleavage rates were obtained with cumulus Cells than with Sertoli Cells (P < 0.005, two-way ANOVA), which probably was due to the superior Cell-cycle synchrony of cumulus Cells at G0/G1. After embryo transfer, there was a significant effect of Cell type on the birth rate, with Sertoli Cells giving the better result (P < 0.005). Furthermore, there was a significant interaction (P < 0.05) between the Cell type and genotype, which indicates that Cloning efficiency is dete...

  • effects of donor Cell type and genotype on the efficiency of mouse somatic Cell Cloning
    Biology of Reproduction, 2003
    Co-Authors: Kimiko Inoue, Narumi Ogonuki, Yoshie Yamamoto, Keiji Mochida, Kaoru Takano, Takashi Kohda, Fumitoshi Ishino, Atsuo Ogura
    Abstract:

    Although it is widely assumed that the Cell type and genotype of the donor Cell affect the efficiency of somatic Cell Cloning, little systematic analysis has been done to verify this assumption. The present study was undertaken to examine whether donor Cell type, donor genotype, or a combination thereof increased the efficiency of mouse Cloning. Initially we assessed the developmental ability of embryos that were cloned from cumulus or immature Sertoli Cells with six different genotypes (i.e., 2 x 6 factorial). Significantly better cleavage rates were obtained with cumulus Cells than with Sertoli Cells (P < 0.005, two-way ANOVA), which probably was due to the superior Cell-cycle synchrony of cumulus Cells at G0/G1. After embryo transfer, there was a significant effect of Cell type on the birth rate, with Sertoli Cells giving the better result (P < 0.005). Furthermore, there was a significant interaction (P < 0.05) between the Cell type and genotype, which indicates that Cloning efficiency is determined by a combination of these two factors. The highest mean birth rate (10.8 +/- 2.1%) was obtained with (B6 x 129)F1 Sertoli Cells. In the second series of experiments, we examined whether the developmental ability of clones with the wild-type genotype (JF1) was improved when combined with the 129 genotype. Normal pups were cloned from cumulus and immature Sertoli Cells of the (129 x JF1)F1 and (JF1 x 129)F1 genotypes, whereas no pups were born from Cells with the (B6 x JF1)F1 genotype. The present study clearly demonstrates that the efficiency of somatic Cell Cloning, and in particular fetal survival after embryo transfer, may be improved significantly by choosing the appropriate combinations of Cell type and genotype.

  • early death of mice cloned from somatic Cells
    Nature Genetics, 2002
    Co-Authors: Narumi Ogonuki, Kimiko Inoue, Yoshie Yamamoto, Yoko Noguchi, Kentaro Tanemura, Osamu Suzuki, Hiroyuki Nakayama, Kunio Doi, Yukiko Ohtomo, Michiko Satoh
    Abstract:

    Here we report that the lifespan of mice cloned from somatic Cells is significantly shorter than that of genotype- and sex-matched controls, most likely due to severe pneumonia and hepatic failure. This finding demonstrates the possibility of long-term deleterious effects of somatic-Cell Cloning, even after normal birth.

David A Hafler - One of the best experts on this subject based on the ideXlab platform.

  • The Journal of Experimental Medicine Loss of Functional Suppression by CD4 ϩ CD25 ϩ Regulatory T Cells in Patients with Multiple Sclerosis
    2020
    Co-Authors: Exp J Med, Howard L Weiner, Vissia Viglietta, Clare Baecher-allan, David A Hafler
    Abstract:

    Abstract CD4 ϩ CD25 ϩ regulatory T Cells contribute to the maintenance of peripheral tolerance by active suppression because their deletion causes spontaneous autoimmune diseases in mice. Human CD4 ϩ regulatory T Cells expressing high levels of CD25 are suppressive in vitro and mimic the activity of murine CD4 ϩ CD25 ϩ regulatory T Cells. Multiple sclerosis (MS) is an inflammatory disease thought to be mediated by T Cells recognizing myelin protein peptides. We hypothesized that altered functions of CD4 ϩ CD25 hi regulatory T Cells play a role in the breakdown of immunologic self-tolerance in patients with MS. Here, we report a significant decrease in the effector function of CD4 ϩ CD25 hi regulatory T Cells from peripheral blood of patients with MS as compared with healthy donors. Differences were also apparent in single Cell Cloning experiments in which the Cloning frequency of CD4 ϩ CD25 hi T Cells was significantly reduced in patients as compared with normal controls. These data are the first to demonstrate alterations of CD4 ϩ CD25 hi regulatory T Cell function in patients with MS

  • increased frequencies of myelin oligodendrocyte glycoprotein mhc class ii binding cd4 Cells in patients with multiple sclerosis
    Journal of Immunology, 2011
    Co-Authors: Khadir Raddassi, Sally C Kent, Junbao Yang, Kasia Bourcier, Elizabeth M Bradshaw, Vicki Seyfertmargolis, Gerald T Nepom, William W Kwok, David A Hafler
    Abstract:

    Multiple sclerosis (MS) is an autoimmune disease characterized by infiltration of pathogenic immune Cells in the CNS resulting in destruction of the myelin sheath and surrounding axons. We and others have previously measured the frequency of human myelin-reactive T Cells in peripheral blood. Using T Cell Cloning techniques, a modest increase in the frequency of myelin-reactive T Cells in patients as compared with control subjects was observed. In this study, we investigated whether myelin oligodendrocyte glycoprotein (MOG)-specific T Cells could be detected and their frequency was measured using DRB1*0401/MOG97–109(107E-S) tetramers in MS subjects and healthy controls expressing HLA class II DRB1*0401. We defined the optimal culture conditions for expansion of MOG-reactive T Cells upon MOG peptide stimulation of PMBCs. MOG97–109-reactive CD4+ T Cells, isolated with DRB1*0401/MOG97–109 tetramers, and after a short-term culture of PMBCs with MOG97–109 peptides, were detected more frequently from patients with MS as compared with healthy controls. T Cell clones from single Cell Cloning of DRB1*0401/MOG97–109(107E-S) tetramer+ Cells confirmed that these T Cell clones were responsive to both the native and the substituted MOG peptide. These data indicate that autoantigen-specific T Cells can be detected and enumerated from the blood of subjects using class II tetramers, and the frequency of MOG97–109-reactive T Cells is greater in patients with MS as compared with healthy controls.

  • loss of functional suppression by cd4 cd25 regulatory t Cells in patients with multiple sclerosis
    Journal of Experimental Medicine, 2004
    Co-Authors: Vissia Viglietta, Clare Baecherallan, Howard L Weiner, David A Hafler
    Abstract:

    CD4+CD25+ regulatory T Cells contribute to the maintenance of peripheral tolerance by active suppression because their deletion causes spontaneous autoimmune diseases in mice. Human CD4+ regulatory T Cells expressing high levels of CD25 are suppressive in vitro and mimic the activity of murine CD4+CD25+ regulatory T Cells. Multiple sclerosis (MS) is an inflammatory disease thought to be mediated by T Cells recognizing myelin protein peptides. We hypothesized that altered functions of CD4+CD25hi regulatory T Cells play a role in the breakdown of immunologic self-tolerance in patients with MS. Here, we report a significant decrease in the effector function of CD4+CD25hi regulatory T Cells from peripheral blood of patients with MS as compared with healthy donors. Differences were also apparent in single Cell Cloning experiments in which the Cloning frequency of CD4+CD25hi T Cells was significantly reduced in patients as compared with normal controls. These data are the first to demonstrate alterations of CD4+CD25hi regulatory T Cell function in patients with MS.

  • changes in cytokine secretion induced by altered peptide ligands of myelin basic protein peptide 85 99
    Journal of Immunology, 1997
    Co-Authors: Lara J Ausubel, Jeffrey I Krieger, David A Hafler
    Abstract:

    Myelin basic protein (MBP)-specific T Cells were isolated directly from peripheral blood by stimulation either with native MBPp85-99 or altered peptide ligands (APLs) in which substitutions of the lysine were made at position 93, a TCR contact residue. We report here that the APL 93A could alter the cytokine profile of some autoreactive MBPp85-99 reactive T Cell clones, switching them from a Th0 phenotype secreting high concentrations of IL-4, IL-5, and IFN-gamma into Th2 Cells secreting significantly less IFN-gamma. However, in vitro stimulation with the 93A peptide, in some instances, induced T Cells that responded better to the native MBPp85-99 peptide. Functionally, the APL 93A was shown to act as an antagonist for IFN-gamma secretion. Based on TCR sequencing and single Cell Cloning, this alteration in cytokine profile was determined to be the result of the differential activation of individual T Cell clones. We discuss the implications of these data for the strength of signal model of T Cell activation.