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1.
Transplant Proc ; 50(1): 250-258, 2018.
Article in English | MEDLINE | ID: mdl-29407319

ABSTRACT

BACKGROUND: Hydrogen (H2) and carbon monoxide (CO) gas are both reported to reduce reactive oxygen species and alleviate tissue ischemia-reperfusion (I-R) injury. The present study was conducted to evaluate the effects of a mixture of H2 gas and CO gas (dual gas) in comparison with hydrogen gas (H2: 2%) alone on I-R renal injury (composition of dual gas; N2: 77.8%; O2: 20.9%; H2: 1.30%; CO: 250 parts per million). METHODS: Adult male Sprague-Dawley rats (body weight 250-280 g) were divided into 5 groups: (1) sham operation control, (2) dual gas inhalation (dual treatment) without I-R treatment, (3) I-R renal injury, (4) H2 gas alone inhalation (H2 treatment) with I-R renal injury, and (5) dual treatment with I-R renal injury. I-R renal injury was induced by clamping the left renal artery and vein for 45 minutes followed by reperfusion, and then contralateral nephrectomy was performed 2 weeks later. Renal function was markedly decreased at 24 hours after reperfusion, and thereafter the effects of dual gas were assessed by histologic examination and determination of the superoxide radical, together with functional and molecular analyses. RESULTS: Pathologic examination of the kidney of I-R rats revealed severe renal damage. Importantly, cytoprotective effects of the dual treatment in comparison with H2 treatment and I-R renal injury were observed in terms of superoxide radical scavenging activity and histochemical features. Rats given dual treatment and I-R renal injury showed significant decreases in blood urea nitrogen. Increased expression of several inflammatory cytokines (tumor necrosis factor-α, interleukin-6, intracellular adhesion molecule-1, nuclear factor-κB, hypoxia inducible factor-1α, and heme oxygenase-1) was attenuated by the dual treatment. CONCLUSIONS: Dual gas inhalation decreases oxidative stress and markedly improves I-R-induced renal injury.


Subject(s)
Antioxidants/pharmacology , Carbon Monoxide/pharmacology , Hydrogen/pharmacology , Nephrectomy , Oxidative Stress/drug effects , Reperfusion Injury/drug therapy , Administration, Inhalation , Animals , Blood Urea Nitrogen , Cytokines/metabolism , Drug Therapy, Combination , Kidney/drug effects , Kidney/surgery , Kidney Function Tests , Male , Rats , Rats, Sprague-Dawley , Reactive Oxygen Species/metabolism , Renal Artery/surgery , Reperfusion Injury/etiology
3.
Phys Rev Lett ; 117(8): 082503, 2016 Aug 19.
Article in English | MEDLINE | ID: mdl-27588852

ABSTRACT

We present an improved search for neutrinoless double-beta (0νßß) decay of ^{136}Xe in the KamLAND-Zen experiment. Owing to purification of the xenon-loaded liquid scintillator, we achieved a significant reduction of the ^{110m}Ag contaminant identified in previous searches. Combining the results from the first and second phase, we obtain a lower limit for the 0νßß decay half-life of T_{1/2}^{0ν}>1.07×10^{26} yr at 90% C.L., an almost sixfold improvement over previous limits. Using commonly adopted nuclear matrix element calculations, the corresponding upper limits on the effective Majorana neutrino mass are in the range 61-165 meV. For the most optimistic nuclear matrix elements, this limit reaches the bottom of the quasidegenerate neutrino mass region.

4.
Chem Commun (Camb) ; 48(52): 6514-6, 2012 Jul 04.
Article in English | MEDLINE | ID: mdl-22618082

ABSTRACT

Competitive inhibitors of either α-galactosidase (α-Gal) or ß-galactosidase (ß-Gal) with high affinity and selectivity have been accessed by exploiting aglycone interactions with conformationally locked sp(2)-iminosugars. Selected compounds were profiled as potent pharmacological chaperones for mutant lysosomal α- and ß-Gal associated with Fabry disease and GM(1) gangliosidosis.


Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Fabry Disease/drug therapy , Gangliosidosis, GM1/drug therapy , alpha-Galactosidase/antagonists & inhibitors , beta-Galactosidase/antagonists & inhibitors , Fabry Disease/enzymology , Fabry Disease/genetics , Fibroblasts/drug effects , Fibroblasts/enzymology , Fibroblasts/metabolism , Gangliosidosis, GM1/enzymology , Gangliosidosis, GM1/genetics , Humans , Imino Sugars/chemistry , Models, Molecular , Mutation , alpha-Galactosidase/genetics , beta-Galactosidase/genetics
5.
Cell Death Dis ; 2: e198, 2011 Sep 01.
Article in English | MEDLINE | ID: mdl-21881600

ABSTRACT

The Nogo receptor and paired immunoglobulin-like receptor B (PIR-B) are receptors for three myelin-derived axon-growth inhibitors, including myelin-associated glycoprotein (MAG). In this study, we report that the p75 receptor is required for the signal transduction of PIR-B, which interacted with p75 upon ligand binding. In addition, p75 was required for activation of Src homology 2-containing protein tyrosine phosphatase (SHP), which is induced by MAG binding to PIR-B. Mice carrying a mutation in the p75 gene showed promotion of axonal regeneration after optic nerve injury. Thus, our results indicate that p75 has a critical role in axon growth inhibition in specific neuronal tracts.


Subject(s)
Axons/physiology , Receptor, Nerve Growth Factor/metabolism , Receptors, Immunologic/metabolism , Animals , COS Cells , Chlorocebus aethiops , Mice , Mice, Inbred C57BL , Mutation , Myelin-Associated Glycoprotein/metabolism , Protein Binding , Protein Tyrosine Phosphatases/chemistry , Protein Tyrosine Phosphatases/metabolism , Receptor, Nerve Growth Factor/genetics , Receptor, trkB/metabolism , Signal Transduction , src Homology Domains
6.
Eur Respir J ; 38(3): 688-701, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21273385

ABSTRACT

Mycobacteria are among the most common causes of hypersensitivity pneumonitis (HP), but controversy persists with regard to the involvement of the infectious potency of the organism in mycobacterial HP (hot tub lung). This study aimed to establish a mouse model of hot tub lung to clarify its pathophysiology. Mice were exposed intranasally to formalin-killed Mycobacterium avium from a patient with hot tub lung (HP strain) or chronic pulmonary infection (non-HP strain), and bronchoalveolar lavage fluids and lung tissues were evaluated for allergic inflammation. Dead M. avium HP strain, but not non-HP strain, elicited marked HP-like pulmonary inflammation in wild-type mice. Although the inflammation was induced in mice lacking CD4 or CD8, the induction of HP-like responses was prevented in mice lacking myeloid differentiation factor (MyD)88 or Toll-like receptor (TLR)9. Cultured lung CD11c+ cells responded to M. avium in a TLR9-dependent manner, and reconstitution of TLR9-/- mice with lung CD11c+ cells from wild-type mice restored the inflammatory responses. Further investigation revealed that pulmonary exposure to M. avium HP strain increased the number of lung CD11b+ CD11c+ cells (dendritic cells) through TLR9 signalling. Our results provide evidence that hot tub lung develops via the mycobacterial engagement of TLR9-MyD88 signalling in lung CD11b+ dendritic cells independent of the mycobacterial infectious capacity.


Subject(s)
Alveolitis, Extrinsic Allergic/metabolism , Alveolitis, Extrinsic Allergic/microbiology , CD11b Antigen/biosynthesis , CD11c Antigen/biosynthesis , Mycobacterium/metabolism , Myeloid Differentiation Factor 88/metabolism , Toll-Like Receptor 9/metabolism , Aged , Animals , Female , Humans , Immunity, Innate , Lung/metabolism , Male , Mice , Mice, Inbred C57BL , Mycobacterium avium/metabolism , Signal Transduction
7.
Clin Exp Immunol ; 162(2): 315-24, 2010 Nov.
Article in English | MEDLINE | ID: mdl-20819092

ABSTRACT

Immunoglobulins (Igs) play important immunomodulatory effects on allergic asthma. Among these, IgG has been reported to regulate allergic inflammation in previous studies about immunotherapy and intravenous immunoglobulin therapy. In this study, to examine the immunomodulatory mechanisms of IgG and FcRs we evaluated the effects of intravenous (i.v.) rabbit IgG administration (IVIgG) on allergic airway inflammation and lung antigen-presenting cells (APCs) in a murine model of ovalbumin (OVA) sensitization and challenge. In OVA-challenged mice, IVIgG attenuated airway eosinophilia, airway hyperresponsiveness and goblet cell hyperplasia and also inhibited the local T helper type (Th) 2 cytokine levels. Additionally, IVIgG attenuated the proliferation of OVA-specific CD4(+) T cells transplanted into OVA-challenged mice. Ex vivo co-culture with OVA-specific CD4(+) cells and lung CD11c(+) APCs from mice with IVIgG revealed the attenuated transcription level of Th2 cytokines, suggesting an inhibitory effect of IVIgG on CD11c(+) APCs to induce Th2 response. Next, to analyse the effects on Fcγ receptor IIb and dendritic cells (DCs), asthmatic features in Fcγ receptor IIb-deficient mice were analysed. IVIgG failed to attenuate airway eosinophilia, airway inflammation and goblet cell hyperplasia. However, the lacking effects of IVIgG on airway eosinophilia in Fcγ receptor IIb deficiency were restored by i.v. transplantation of wild-type bone marrow-derived CD11c(+) DCs. These results demonstrate that IVIgG attenuates asthmatic features and the function of lung CD11c(+) DCs via Fcγ receptor IIb in allergic airway inflammation. Targeting Fc portions of IgG and Fcγ receptor IIb on CD11c(+) DCs in allergic asthma is a promising therapeutic strategy.


Subject(s)
Asthma/therapy , CD11c Antigen/metabolism , Dendritic Cells/drug effects , Immunoglobulin G/pharmacology , Immunoglobulins, Intravenous/pharmacology , Receptors, IgG/genetics , Adoptive Transfer , Animals , Antigen Presentation/drug effects , Antigen Presentation/immunology , Asthma/immunology , Asthma/pathology , Asthma/physiopathology , Bronchial Hyperreactivity/physiopathology , Bronchial Hyperreactivity/prevention & control , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/cytology , CD4-Positive T-Lymphocytes/cytology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Cell Count , Cell Differentiation/drug effects , Cell Differentiation/immunology , Cell Proliferation , Cytokines/metabolism , Dendritic Cells/immunology , Dendritic Cells/metabolism , Dendritic Cells/transplantation , Disease Models, Animal , Eosinophils/cytology , Female , Immunoglobulin E/blood , Immunoglobulin G/therapeutic use , Immunoglobulins, Intravenous/therapeutic use , Immunologic Factors/pharmacology , Immunologic Factors/therapeutic use , Inflammation/immunology , Inflammation/pathology , Inflammation/prevention & control , Mice , Mice, Inbred C57BL , Ovalbumin/immunology , Specific Pathogen-Free Organisms , Th2 Cells/immunology
8.
Colloids Surf B Biointerfaces ; 77(1): 18-21, 2010 May 01.
Article in English | MEDLINE | ID: mdl-20116978

ABSTRACT

Properties of various carbon nanomaterials in bilirubin adsorption have been studied to develop a new adsorbent in the plasma apheresis. Carbon nanomaterials we used as adsorbents are single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), and single-walled carbon nanohorns (SWNHs). The adsorbent was mixed with a bilirubin solution, and the adsorption capacity was obtained by measuring the concentrations of residual bilirubin in the solution after the adsorption process. We found that the bundled MWCNTs exhibit the largest capacity in the saturated amount of adsorbed bilirubin among the examined materials, and that the oxidized SWNHs exhibit the fastest rate in the early stage of the adsorption. We also found that the amount of adsorbed bilirubin increases with an increase in the dispersibility of the adsorbent.


Subject(s)
Bilirubin/chemistry , Nanotubes, Carbon , Adsorption , Kinetics , Surface Properties
9.
Br J Cancer ; 102(5): 916-21, 2010 Mar 02.
Article in English | MEDLINE | ID: mdl-20145612

ABSTRACT

BACKGROUND: We previously reported that a faecal cyclooxygenase-2 (COX-2) mRNA assay was useful for identifying colorectal cancer (CRC). This study sought to investigate the factors that contribute to faecal COX-2 mRNA expression in subjects with CRC. METHODS: The study cohort comprised 78 patients with CRC and 36 control subjects. The expressions of COX-2, beta-2-microglobulin (B2M), carcinoembryonic antigen (CEA), E-cadherin (E-cad), and CD45 mRNA in faeces and COX-2 mRNA expression in tissue were determined by quantitative real-time RT-PCR. RESULTS: The level of faecal expression of COX-2 mRNA in CRC was significantly higher than that in controls. A significant correlation was found between faecal COX-2 mRNA expression and faecal B2M, CEA, E-cad, or CD45 mRNAs, markers of exfoliated total cells, colonocytes, and leukocytes, respectively. A significant correlation was found between the expression of COX-2 mRNA in faeces and tumour surface area, COX-2 mRNA expression in primary tumour. There was no difference in faecal COX-2 mRNA expression between proximal CRC and distal CRC. CONCLUSION: COX-2 mRNA expression in faeces seems to originate from tumour lesion and to be affected by factors such as the number of exfoliated cells, exfoliation of inflammatory cells, COX-2 mRNA expression in tumour, and tumour size.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Cyclooxygenase 2/genetics , Feces/chemistry , RNA, Messenger/genetics , Adult , Aged , Aged, 80 and over , Biomarkers, Tumor/metabolism , Cadherins/genetics , Cadherins/metabolism , Carcinoembryonic Antigen/genetics , Carcinoembryonic Antigen/metabolism , Case-Control Studies , Cohort Studies , Colon/metabolism , Colon/pathology , Colorectal Neoplasms/metabolism , Cyclooxygenase 2/metabolism , Female , Humans , Male , Middle Aged , Prognosis , RNA, Messenger/metabolism , Rectum/metabolism , Rectum/pathology , Reverse Transcriptase Polymerase Chain Reaction , Survival Rate , Young Adult , beta 2-Microglobulin/genetics , beta 2-Microglobulin/metabolism
11.
Allergy ; 64(9): 1366-74, 2009 Sep.
Article in English | MEDLINE | ID: mdl-19416145

ABSTRACT

BACKGROUND: House dust mites produce serine and cysteine proteases. Mite-derived proteases have been suggested to be involved in the pathogenesis of allergies; however, whether mite-derived serine protease activity can stimulate keratinocytes remains unknown. METHODS: We examined the activation of primary human keratinocytes by serine protease-rich extract of whole mite culture and compared with that by recombinant group 1 allergens (rDer f 1 and rDer p 1), which exclusively exhibit cysteine protease activity. RESULTS: Protease activity of whole mite culture extract (WCE), rDer f 1 and rDer p 1 induced the release of IL-8 and granulocyte-macrophage colony-stimulating factor. Protease activity of WCEs induced a significant upregulation of their mRNA expression but rDer f 1 had much less effect. Protease activity of the WCE stimulated intracellular Ca(2+) mobilization but rDer f 1 and rDer p 1 did not. The mobilization induced by agonists for the human protease-activated receptor (PAR)-2, an agonist peptide or trypsin, was diminished by pre-incubation of keratinocytes with WCE. rDer f 1 inefficiently cleaved a synthetic N-terminal peptide of PAR-2 at different sites from trypsin, but the resultant peptides did not stimulate the release of interleukin-8. CONCLUSIONS: The results suggest that mite-derived serine protease activity may contribute to the pathogenesis of atopic dermatitis by activating keratinocytes via PAR-2 activation but cysteine protease activity of Der f 1 and Der p 1 acts via another mechanism.


Subject(s)
Dermatitis, Atopic/immunology , Keratinocytes/immunology , Pyroglyphidae/enzymology , Receptor, PAR-2/metabolism , Serine Proteases/immunology , Animals , Antigens, Dermatophagoides/metabolism , Antigens, Dermatophagoides/pharmacology , Arthropod Proteins , Calcium/metabolism , Cells, Cultured , Cysteine Endopeptidases , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Interleukin-8/metabolism , Keratinocytes/drug effects , Peptides/pharmacology , Pyroglyphidae/immunology , RNA, Messenger/metabolism , Receptor, PAR-2/agonists , Recombinant Proteins/metabolism , Recombinant Proteins/pharmacology , Serine Proteases/pharmacology
12.
Colloids Surf B Biointerfaces ; 71(2): 255-9, 2009 Jul 01.
Article in English | MEDLINE | ID: mdl-19327971

ABSTRACT

Bilirubin adsorption on carbon nanotube surfaces has been studied to develop a new adsorbent in the plasma apheresis. Powder-like carbon nanotubes were first examined under various adsorption conditions such as temperatures and initial concentrations of bilirubin solutions. The adsorption capacity was measured from the residual concentrations of bilirubin in the solution after the adsorption process using a visible absorption spectroscopy. We found that multi-walled carbon nanotubes (MWCNTs) exhibit greater adsorption capacity for bilirubin molecules than that of single-walled carbon nanotubes (SWCNTs). To guarantee the safety of the adsorbents, we fabricated carbon nanotube sheets in which leakage of CNTs to the plasma is suppressed. Since SWCNTs are more suitable for robust sheets, a complex sheet consisting of SWCNTs as the scaffolds and MWCNTs as the efficient adsorbents. CNT/polyaniline complex sheets were also fabricated. Bilirubin adsorption capacity of CNTs has been found to be much larger than that of the conventional materials because of their large surface areas and large adsorption capability for polycyclic compound molecules due to their surface structure similar to graphite.


Subject(s)
Bilirubin/chemistry , Nanotubes, Carbon/chemistry , Adsorption , Aniline Compounds/chemistry , Nanotubes, Carbon/ultrastructure , Powders , Spectrum Analysis, Raman , Time Factors
13.
Biochem Biophys Res Commun ; 324(4): 1340-5, 2004 Nov 26.
Article in English | MEDLINE | ID: mdl-15504361

ABSTRACT

The squamous cell carcinoma antigen 1 (SCCA1) and SCCA2 are unique serpins that can inhibit cysteine proteinases. SQN-5, their mouse ortholog, has already been identified, and its inhibitory property has been characterized; however, its biological role has remained undefined. Furthermore, no other mouse homolog of SQN-5 has been known. We characterize three mouse members of SCCA-related molecules including SQN-5 in this article. Serpinb3a (SQN-5) and Serpinb3b, but not Serpinb3c, were functional, inhibiting both serine and cysteine proteinases with different inhibitory profiles due to the difference of two amino acids in their reactive site loops. Serpinb3a was ubiquitously expressed in most tissues, whereas expression of Serpinb3b was limited to keratinocytes. Keratinocytes secreted both SCCA-related proteins, Serpinb3a and Serpinb3b. These results indicate that Serpinb3a and Serpinb3b may play different roles by inhibiting intrinsic or extrinsic proteinases with different expression distributions and different inhibitory profiles.


Subject(s)
Serpins/genetics , Serpins/physiology , Amino Acid Sequence , Animals , Antigens, Neoplasm/classification , Chromosome Mapping , Keratinocytes/metabolism , Mice , Molecular Sequence Data , Sequence Alignment , Serpins/chemistry , Serpins/classification
14.
J Immunol ; 167(6): 3427-34, 2001 Sep 15.
Article in English | MEDLINE | ID: mdl-11544335

ABSTRACT

It has been shown that IgE binding to FcepsilonRI on mast cells results in increased FcepsilonRI expression, which in turn enhances IgE-dependent chemical mediator release from mast cells. Therefore, prevention of the IgE-mediated FcepsilonRI up-regulation would be a promising strategy for management of allergic disorders. However, the mechanism of IgE-mediated FcepsilonRI up-regulation has not been fully elucidated. In this study, we analyzed kinetics of FcepsilonRI on peritoneal mast cells and bone marrow-derived mast cells. In the presence of brefeldin A, which prevented transport of new FcepsilonRI molecules to the cell surface, levels of IgE-free FcepsilonRI on mast cells decreased drastically during culture, whereas those of IgE-bound FcepsilonRI were stable. In contrast, levels of FcgammaRIII on the same cells were stable even in the absence of its ligand, indicating that FcepsilonRI alpha-chain, but not beta- and gamma-chains, was responsible for the instability of IgE-free FcepsilonRI. As far as we analyzed, there was no evidence to support the idea that IgE binding to FcepsilonRI facilitated synthesis and/or transport of FcepsilonRI to the cell surface. Therefore, the stabilization and accumulation of FcepsilonRI on the cell surface through IgE binding appears to be the major mechanism of IgE-mediated FcepsilonRI up-regulation.


Subject(s)
Cell Membrane/metabolism , Immunoglobulin E/pharmacology , Mast Cells/drug effects , Receptors, IgE/biosynthesis , Up-Regulation/drug effects , Animals , Bone Marrow Cells/drug effects , Bone Marrow Cells/metabolism , Brefeldin A/pharmacology , Drug Stability , Humans , Immunoglobulin E/blood , Immunoglobulin E/immunology , Immunoglobulin E/metabolism , Ligands , Mast Cells/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Transgenic , Protein Binding , Protein Subunits , Receptors, IgE/chemistry , Receptors, IgE/genetics , Recombinant Fusion Proteins/pharmacology , Transcription, Genetic
15.
Immunol Rev ; 181: 215-22, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11513143

ABSTRACT

Clones for murine paired immunoglobulin-like receptors (PIR) were first isolated as those coding for type I transmembrane glycoproteins with six immunoglobulin-like domains homologous to human Fc alphaR, bovine Fc gamma2R, and other related receptors. However, they turned out to bind neither IgA nor other immunoglobulins in the case of the ectopic expression on COS-1 fibroblastic cells. PIR-A and B are expressed on a wide variety of cells in the murine immune system, such as in B cells, mast cells, macrophages, and dendritic cells, mostly in a pairwise fashion. PIR-A requires homodimeric Fc receptor common gamma chain, which harbors an immunoreceptor tyrosine-based activation motif, for its efficient cell surface expression and for the delivery of activation signaling. In contrast, PIR-B contains immunoreceptor tyrosine-based inhibitory motifs (ITIMs) in its cytoplasmic portion and inhibits receptor-mediated activation signaling in vitro upon engagement with other activating-type receptors such as the antigen receptor on B cells and the high affinity Fc receptor for IgE on mast cells. ITIMs of PIR-B on macrophages and B cells have been shown to be constitutively phosphorylated in their tyrosine residues. Although the ligand for PIR still remains unknown, the transgenics and the gene-targeted mice will provide us with valuable information on their physiological roles in the immune regulation.


Subject(s)
Receptors, Immunologic/metabolism , Animals , Biological Evolution , Cattle , Chromosome Mapping , Gene Expression , Humans , Mice , Receptors, Immunologic/chemistry , Receptors, Immunologic/genetics , Signal Transduction
16.
Hepatogastroenterology ; 48(40): 1206-8, 2001.
Article in English | MEDLINE | ID: mdl-11490835

ABSTRACT

An 84-year-old man presented with complaints of epigastric discomfort. Upper gastrointestinal series and endoscopy showed an elevated lesion at the posterior wall of greater curvature on the gastric fundus. Diagnosed as moderately differentiated tubular adenocarcinoma by biopsy, wedge resection and 4sa regional lymph node dissection were carried out. The tumor morphology showed type I with slight elevation, 2.5 x 1.7 cm in size; histological showed papillary, tubular, and solid formations having clear cytoplasm and large bizarre nuclei invading the deep submucosal layer (sm2). This case was evaluated as T1(sm) N0 M0 stage Ia early gastric cancer. In the 5th month after operation, multiple liver metastases were detected. He died of liver failure by rapid growth of metastatic tumors in the 6th month after operation. The serum alpha-fetoprotein level at recurrence was 1,900 ng/mL, and alpha-fetoprotein-positive cells were immunohistochemically detected in operative and liver biopsy specimens.


Subject(s)
Liver Neoplasms/secondary , Stomach Neoplasms/metabolism , alpha-Fetoproteins/analysis , Aged , Aged, 80 and over , Fatal Outcome , Humans , Immunohistochemistry , Male , Stomach Neoplasms/pathology
17.
Biosci Biotechnol Biochem ; 65(7): 1601-9, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11515545

ABSTRACT

Recently, we reported that introduction of mutations that induced conformational changes of the major mite allergen Der f 2 was an efficient strategy to reduce the allergenicity for safer allergen-specific immunotherapy. In this study, we evaluated another strategy, disruption of two independent IgE epitopes without inducing conformational change. We analyzed allergenicities of the wild-type Der f 2, two single mutants with a mutation at either of the two IgE-binding sites (K15A and K77A), and a double mutant with mutations at both of the sites (K15/77A). Purified recombinant forms of Der f 2 expressed in Escherichia coli had correct disulfide bonds, equivalent apparent molecular masses of approximately 15 kDa, and similar secondary structures. The mutants of Der f 2 had less IgE reactivities than the wild-type Der f 2 and reduced inhibitory activities for IgE-binding to the wild-type Der f 2. However, the mutations did not significantly reduce histamine-releasing activity.


Subject(s)
Allergens/genetics , Glycoproteins/genetics , Glycoproteins/immunology , Mites/genetics , Mites/immunology , Mutation , Allergens/chemistry , Allergens/metabolism , Animals , Antigens, Dermatophagoides , Basophils/immunology , Binding Sites/genetics , Escherichia coli/genetics , Glycoproteins/chemistry , Glycoproteins/metabolism , Histamine Release , Humans , Immunoglobulin E/metabolism , In Vitro Techniques , Models, Molecular , Protein Conformation , Protein Folding , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/immunology , Recombinant Proteins/metabolism
18.
Biosci Biotechnol Biochem ; 65(5): 1082-9, 2001 May.
Article in English | MEDLINE | ID: mdl-11440121

ABSTRACT

We describe the preparation of Fab fragments of a humanized anti-human high-affinity IgE receptor (Fc epsilonRIalpha) antibody potentially useful for treatment of IgE-mediated allergic diseases. IgE-binding capacities of sixteen combinations of light and heavy chains of four recombinant anti-Fc epsilonRIalpha antibodies, chimeric CRA2, humanized CRA2, chimeric CRA4, and humanized CRA4, were compared. A combination in which both chains were of humanized CRA2 had the highest activity. Stable transfectant clones of four kinds of host cells expressing recombinant antibodies were established. CHO-K1 cells were the most productive. Serum-free media suitable for culture of the stable CHO-transfectant clones were screened. The concentration of the humanized CRA2, which the most productive clone secreted into the chosen serum-free medium, was approximately 100 microg/ml. A procedure for the purification of the antibody, papain-digestion, and purification of Fab fragments was established. The highly purified humanized Fab fragments are suitable for use to examine their in vivo activity and immunogenicity in primates.


Subject(s)
Antibodies/immunology , Immunoglobulin Fab Fragments/isolation & purification , Receptors, IgE/immunology , Animals , CHO Cells , Cell Separation , Cricetinae , Culture Media, Serum-Free , Enzyme-Linked Immunosorbent Assay , Flow Cytometry , Humans , Immunoglobulin E/immunology , Immunoglobulin Fab Fragments/immunology , Papain/chemistry
20.
Int Arch Allergy Immunol ; 124(4): 454-60, 2001 Apr.
Article in English | MEDLINE | ID: mdl-11340328

ABSTRACT

BACKGROUND: The group 1 allergens from mite feces, which belong to the papain-like cysteine protease family, are the most significant in-door allergens. In this study, we analyzed the contribution of the cysteine residues and N-glycosylation in Der f 1, the group 1 allergen from Dermatophagoides farinae, to secretion and maturation by using systems for expression of recombinant Der f 1 (rDer f 1). METHODS: The rDer f 1 and its mutants were expressed in yeast Pichia pastoris and insect SF9 cells. Secretion of their proforms was checked by SDS-PAGE or immunoblotting. Protease activities of the secreted proform of a mutant and the mature form were compared with that of native Der f 1. RESULTS: The proform of a mutant Der f 1, pro-N53Q, whose consensus motif for N-glycosylation was disrupted, was not secreted in insect SF9 cells although secreted in P. pastoris. Indirect evidence was obtained to support the disulfide bond formation between Cys4 and Cys118, which were not conserved in papain. A mutant for Cys35 in the catalytic site of the cysteine protease, pro-C35S/N53Q, was secreted, but the other mutants for cysteines concerning intramolecular disulfide bonds were not secreted in P. pastoris. The prosequence of pro-C35S/N53Q was removed by an in vitro activation process. The mature C35S/N53Q showed low protease activity. CONCLUSION: N-glycosylation is essential for secretion in insect SF9 cells but not in P. pastoris. Disulfide bonds are essential for secretion in P. pastoris. A mutation in the catalytic site, C35S, is not completely critical to removal of the prosequence and protease activity. The findings are useful for future design of recombinant products for application in immunotherapy.


Subject(s)
Glycoproteins/genetics , Glycoproteins/metabolism , Amino Acid Motifs , Animals , Antigens, Dermatophagoides , Cysteine/genetics , Cysteine Endopeptidases/genetics , Cysteine Endopeptidases/metabolism , Glycosylation , Mutagenesis, Site-Directed , Pichia/genetics , Protein Precursors/genetics , Protein Precursors/metabolism , Recombinant Proteins , Spodoptera/genetics , Transfection
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