Expression of XMyoD protein in early Xenopus laevis embryos

Development ◽  
1992 ◽  
Vol 114 (1) ◽  
pp. 31-38 ◽  
Author(s):  
N.D. Hopwood ◽  
A. Pluck ◽  
J.B. Gurdon ◽  
S.M. Dilworth
Keyword(s):  
Monoclonal Antibody ◽  
The Other ◽  
N Terminus ◽  
Tailbud Stage ◽  
Frog Development ◽  
Myogenic Factor ◽  
Myogenic Factors ◽  
Somitic Mesoderm ◽  
Xenopus Laevis Embryos ◽  
Whole Mounts

A monoclonal antibody specific for Xenopus MyoD (XMyoD) has been characterized and used to describe the pattern of expression of this myogenic factor in early frog development. The antibody recognizes an epitope close to the N terminus of the products of both XMyoD genes, but does not bind XMyf5 or XMRF4, the other two myogenic factors that have been described in Xenopus. It reacts in embryo extracts only with XMyoD, which is extensively phosphorylated in the embryo. The distribution of XMyoD protein, seen in sections and whole-mounts, and by immunoblotting, closely follows that of XMyoD mRNA. XMyoD protein accumulates in nuclei of the future somitic mesoderm from the middle of gastrulation. In neurulae and tailbud embryos it is expressed specifically in the myotomal cells of the somites. XMyoD is in the nucleus of apparently every cell in the myotomes. It accumulates first in the anterior somitic mesoderm, and its concentration then declines in anterior somites from the tailbud stage onwards.

scholarly journals Possible Future Monoclonal Antibody (mAb)-Based Therapy against Arbovirus Infections

2013 ◽  
Vol 2013 ◽  
pp. 1-21 ◽  
Author(s):  
Giuseppe Sautto ◽  
Nicasio Mancini ◽  
Giacomo Gorini ◽  
Massimo Clementi ◽  
Roberto Burioni
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Side Effects ◽  
Antiviral Activity ◽  
The Other ◽  
Viral Escape ◽  
Passive Immunotherapy ◽  
Medical Need

More than 150 arboviruses belonging to different families are known to infect humans, causing endemic infections as well as epidemic outbreaks. Effective vaccines to limit the occurrence of some of these infections have been licensed, while for the others several new immunogens are under development mostly for their improvements concerning safety and effectiveness profiles. On the other hand, specific and effective antiviral drugs are not yet available, posing an urgent medical need in particular for emergency cases. Neutralizing monoclonal antibodies (mAbs) have been demonstrated to be effective in the treatment of several infectious diseases as well as in preliminaryin vitroandin vivomodels of arbovirus-related infections. Given their specific antiviral activity as well-tolerated molecules with limited side effects, mAbs could represent a new therapeutic approach for the development of an effective treatment, as well as useful tools in the study of the host-virus interplay and in the development of more effective immunogens. However, before their use as candidate therapeutics, possible hurdles (e.g., Ab-dependent enhancement of infection, occurrence of viral escape variants) must be carefully evaluated. In this review are described the main arboviruses infecting humans and candidate mAbs to be possibly used in a future passive immunotherapy.

scholarly journals Functional study of a monoclonal antibody to IgE Fc receptor (Fc epsilon R2) of eosinophils, platelets, and macrophages.

1986 ◽  
Vol 164 (1) ◽  
pp. 72-89 ◽  
Author(s):  
M Capron ◽  
T Jouault ◽  
L Prin ◽  
M Joseph ◽  
J C Ameisen ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Lymphocyte ◽  
Specific Binding ◽  
Polyclonal Antibodies ◽  
Fc Receptor ◽  
The Other ◽  
Functional Study ◽  
Low Density ◽  
Fluorescence Staining ◽  
Ige Binding

An IgM mAb (BB10) was produced by immunization of mice with human eosinophils purified according to their abnormal low density ("hypodense" cells), and previously shown to exhibit increased IgE-dependent antiparasite cytotoxicity. This BB10 antibody, selected for positive fluorescence staining of hypodense blood or lung eosinophils and low or negative staining of normodense eosinophils or neutrophils, could strongly inhibit IgE-dependent cytotoxicity of human eosinophils and platelets. The specificity for the IgE Fc receptor was suggested by the high levels of inhibition of IgE rosettes formed by eosinophils after incubation with the purified IgM fraction of BB10, whereas other receptors (Fc gamma R, CR1) were not affected. On the other hand, BB10, able to inhibit rat eosinophil Fc epsilon R, did not react with the IgE Fc receptor on mast cells or basophils. A technique using radioiodinated BB10 allowed us to quantify the specific binding of BB10 to human eosinophils and platelets. Competition experiments revealed a crossinhibition between the binding of BB10 and IgE, suggesting the specificity of BB10 for the IgE binding site of eosinophil, platelet, and monocyte Fc epsilon R. Three proteins having extrapolated Mr of 32,000, 43,000-45,000, and 97,000 were found in the platelet extract eluted from a BB10 or from an IgE immunosorbent column. These findings confirm the similarities between IgE Fc receptors on human eosinophils, platelets, and macrophages, already observed with polyclonal antibodies directed against the B lymphocyte Fc epsilon receptor. They suggest, moreover, that the mAb BB10 can represent a good reagent for further investigations on the structure and the functions of this IgE Fc receptor (Fc epsilon R2).

Xenopus Myf-5 marks early muscle cells and can activate muscle genes ectopically in early embryos

Development ◽  
1991 ◽  
Vol 111 (2) ◽  
pp. 551-560 ◽  
Author(s):  
N.D. Hopwood ◽  
A. Pluck ◽  
J.B. Gurdon
Keyword(s):  
Ectopic Expression ◽  
Muscle Cells ◽  
Muscle Differentiation ◽  
Cardiac Actin ◽  
Early Embryos ◽  
Muscle Genes ◽  
Myogenic Factor ◽  
Somitic Mesoderm

We have cloned a Xenopus cDNA that encodes a homologue of the human myogenic factor, Myf-5. Xenopus Myf-5 (XMyf5) transcripts first accumulate in the prospective somite region of early gastrulae. The pattern of XMyf5 expression is similar to that of the Xenopus MyoD (XMyoD) gene, except that XMyf5 transcripts are largely restricted to posterior somitic mesoderm even before any somites have formed. Transient ectopic expression of XMyf5 activates cardiac actin and XMyoD genes in animal cap cells, but does not cause full myogenesis, even in combination with XMyoD. These results suggest that XMyf5 acts together with XMyoD as one of the set of genes regulating the earliest events of myogenesis, additional factors being required for complete muscle differentiation.

The analysis of 40 kDa nuclear protein, p40, in interphase cells and mitotic cells

1993 ◽  
Vol 106 (3) ◽  
pp. 741-748 ◽  
Author(s):  
Y. Kaneda ◽  
K. Kinoshita ◽  
M. Sato ◽  
K. Tanaka ◽  
Y. Kaneda
Keyword(s):  
Monoclonal Antibody ◽  
Nuclear Envelope ◽  
Nuclear Protein ◽  
Dnase I ◽  
High Salt ◽  
The Other ◽  
Interphase Nuclei ◽  
Interphase Cells ◽  
Detergent Treatment ◽  
Sequential Treatments

We previously reported that the monoclonal antibody M108 recognized a 40 kDa protein both in the nucleus and the cytoplasm. This nuclear 40 kDa antigen was located in the nuclear envelope in interphase cells and in the perichromosomal region during mitosis. Now, we have analyzed this nuclear 40 kDa protein (p40) further, through morphological and biochemical approaches. At the beginning of mitosis, the perinuclear p40 detached from the nuclear envelope and moved to surround the condensing chromatin, while in the late stage of mitosis, the perichromosomal p40 moved back to the reassembled nuclear envelope. Most of the perichromosomal p40 on the metaphase chromosome was solubilized only by DNase I treatment, not by either high salt or detergent treatment. On the other hand, the perinuclear p40 was not solubilized by DNase1 alone, or high salt detergent alone. Sequential treatments with DNase I and high salt detergent were required to extract p40 in interphase nuclei. These results suggest that p40 was associated both with the nuclear envelope and chromatin DNA in interphase nuclei, while it bound only to chromatin DNA in mitosis.

E-box- and MEF-2-independent muscle-specific expression, positive autoregulation, and cross-activation of the chicken MyoD (CMD1) promoter reveal an indirect regulatory pathway

1994 ◽  
Vol 14 (8) ◽  
pp. 5474-5486
Author(s):  
C A Dechesne ◽  
Q Wei ◽  
J Eldridge ◽  
L Gannoun-Zaki ◽  
P Millasseau ◽  
...  
Keyword(s):  
Binding Site ◽  
Binding Sites ◽  
Primary Cultures ◽  
Regulatory Elements ◽  
The Other ◽  
Indirect Pathway ◽  
Specific Expression ◽  
Fibroblast Cultures ◽  
E Box ◽  
Myogenic Factors

Members of the MyoD family of gene-regulatory proteins (MyoD, myogenin, myf5, and MRF4) have all been shown not only to regulate the transcription of numerous muscle-specific genes but also to positively autoregulate and cross activate each other's transcription. In the case of muscle-specific genes, this transcriptional regulation can often be correlated with the presence of a DNA consensus in the regulatory region CANNTG, known as an E box. Little is known about the regulatory interactions of the myogenic factors themselves; however, these interactions are thought to be important for the activation and maintenance of the muscle phenotype. We have identified the minimal region in the chicken MyoD (CMD1) promoter necessary for muscle-specific transcription in primary cultures of embryonic chicken skeletal muscle. The CMD1 promoter is silent in primary chick fibroblast cultures and in muscle cell cultures treated with the thymidine analog bromodeoxyuridine. However, CMD1 and chicken myogenin, as well as, to a lesser degree, chicken Myf5 and MRF4, expressed in trans can activate transcription from the minimal CMD1 promoter in these primary fibroblast cultures. Here we show that the CMD1 promoter contains numerous E-box binding sites for CMD1 and the other myogenic factors, as well as a MEF-2 binding site. Surprisingly, neither muscle-specific and the other myogenic factors, as well as a MEF-2 binding site. Surprisingly, neither muscle-specific expression, autoregulation, or cross activation depends upon the presence of of these E-box or MEF-2 binding sites in the CMD1 promoter. These results demonstrate that the autoregulation and cross activation of the chicken MyoD promoter through the putative direct binding of the myogenic basic helix-loop-helix regulatory factors is mediated through an indirect pathway that involves unidentified regulatory elements and/or ancillary factors.

Comparative Assessment of Fumonisin in Grain-Based Foods by ELISA, GC-MS, and HPLC

1994 ◽  
Vol 57 (2) ◽  
pp. 169-172 ◽  
Author(s):  
JAMES J. PESTKA ◽  
JUAN I. AZCONA-OLIVERA ◽  
RONALD D. PLATTNER ◽  
FIORENZA MINERVINI ◽  
M. BRUNO DOKO ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Monoclonal Antibody ◽  
Food Samples ◽  
Comparative Assessment ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cereal Samples ◽  
Related Compounds ◽  
Positive Results

Seventy-one (71) food samples were analyzed for the mycotoxin fumonisin by a monoclonal antibody based competitive enzyme-linked immunosorbent assay (ELISA). Fumonisins were detected primarily in corn-based products with 7/12, 2/2 and 1/3 and 1/7 yellow cornmeal, blue cornmeal, corn muffin mix, and mixed grain cereal samples yielding positive results, respectively. When the positive samples and randomly selected negative samples were assessed by other methods, correlations (r values) between ELISA and gas chromatography-mass spectrometry (GC-MS), ELISA and high-pressure liquid chromatography (HPLC) and GC-MS and HPLC were 0.478 (p < 0.05), 0.512 (p < 0.05), and 0.946 (p < 0.01), respectively. The results suggested that although the immunoassay could be used for screening of fumonisin in food samples, higher estimates were attained by ELISA than by the other two methods particularly in the more contaminated samples. These observations may result from differences in sample preparation among the methods or because of the presence of structurally related compounds in extracts that are detectable by ELISA but not the other two methods.

Defining a second epitope for heparin-induced thrombocytopenia/thrombosis antibodies using KKO, a murine HIT-like monoclonal antibody

Blood ◽  
2002 ◽  
Vol 99 (4) ◽  
pp. 1230-1236 ◽  
Author(s):  
Zhong Q. Li ◽  
Weiyi Liu ◽  
Kwang S. Park ◽  
Brue S. Sachais ◽  
Gowthani M. Arepally ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Binding Site ◽  
Binding Sites ◽  
Heparin Therapy ◽  
Common Complication ◽  
Platelet Factor ◽  
Heparin Induced Thrombocytopenia ◽  
The Third ◽  
N Terminus ◽  
A Site

Heparin-induced thrombocytopenia/thrombosis (HIT/T) is a common complication of heparin therapy that is caused by antibodies to platelet factor 4 (PF4) complexed with heparin. The immune response is polyclonal and polyspecific, ie, more than one neoepitope on PF4 is recognized by HIT/T antibodies. One such epitope has been previously identified; it involves the domain between the third and fourth cysteine residues in PF4 (site 1). However, the binding sites for other HIT/T antibodies remain to be defined. To explore this issue, the binding site of KKO, an HIT/T-like murine monoclonal antibody, was defined. KKO shares a binding site with many HIT/T antibodies on PF4/heparin, but does not bind to site 1 or recognize mouse PF4/heparin. Therefore, the binding of KKO to a series of mouse/human PF4 chimeras complexed with heparin was examined. KKO recognizes a site that requires both the N terminus of PF4 and Pro34, which immediately precedes the third cysteine. Both regions lie on the surface of the PF4 tetramer in sufficient proximity (within 0.74 nm) to form a contiguous antigenic determinant. The 10 of 14 HIT/T sera that require the N terminus of PF4 for antigen recognition also require Pro34 to bind. This epitope, termed site 2, lies adjacent to site 1 in the crystal structure of the PF4 tetramer. Yet sites 1 and 2 can be recognized by distinct populations of antibodies. These studies further help to define a portion of the PF4 tetramer to which self-reactive antibodies develop in patients exposed to heparin.

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