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1.
Allergol. immunopatol ; 46(4): 378-384, jul.-ago. 2018. tab, graf
Article in English | IBECS | ID: ibc-177869

ABSTRACT

BACKGROUND: The long-term efficacy of corticosteroids to prevent atopic dermatitis (AD) relapses has partially been addressed in children. This study compared an intermittent dosing regimen of fluticasone propionate (FP) cream 0.05% with its vehicle base in reducing the risk of relapse in children with stabilized AD. METHODS: A randomized controlled, multicentric, double-blind trial was conducted. Children (2-10 years) with mild/moderate AD (exclusion criteria: >30% affected body surface area and/or head) were enrolled into an Open-label Stabilization Phase (OSP) of up to 2 weeks on twice daily FP. Those who achieved treatment success entered the Double-blind Maintenance Phase (DMP). They were randomly allocated to receive FP or vehicle twice-weekly on consecutive days for 16 weeks. The primary study endpoint was relapse rate; time to relapse and severity of disease were also studied. Kaplan-Meier estimates were calculated. RESULTS: Fifty-four patients (29 girls) entered the OSP (23 mild AD) and 49 (26 girls) continued into the DMP. Mean age was 5.5 (SD: 2.8) and 5.1 (SD: 2.3) yrs for FP and vehicle groups, respectively. Four patients withdrew from the DMP (two in every group). Patients treated with FP twice weekly had a 2.7 fold lower risk of experiencing a relapse than patients treated with vehicle (relative risk 2.72, SD: 1.28; p = 0.034). FP was also superior to vehicle for delaying time to relapse. Both treatment therapies were well tolerated. CONCLUSION: This long-term study shows that twice weekly FP provides an effective maintenance treatment to control the risk of relapse in children with AD


No disponible


Subject(s)
Humans , Male , Female , Child, Preschool , Child , Anti-Inflammatory Agents/therapeutic use , Dermatitis, Atopic/drug therapy , Fluticasone/therapeutic use , Secondary Prevention/methods , Double-Blind Method
2.
Allergol Immunopathol (Madr) ; 46(4): 378-384, 2018.
Article in English | MEDLINE | ID: mdl-29373242

ABSTRACT

BACKGROUND: The long-term efficacy of corticosteroids to prevent atopic dermatitis (AD) relapses has partially been addressed in children. This study compared an intermittent dosing regimen of fluticasone propionate (FP) cream 0.05% with its vehicle base in reducing the risk of relapse in children with stabilized AD. METHODS: A randomized controlled, multicentric, double-blind trial was conducted. Children (2-10 years) with mild/moderate AD (exclusion criteria: >30% affected body surface area and/or head) were enrolled into an Open-label Stabilization Phase (OSP) of up to 2 weeks on twice daily FP. Those who achieved treatment success entered the Double-blind Maintenance Phase (DMP). They were randomly allocated to receive FP or vehicle twice-weekly on consecutive days for 16 weeks. The primary study endpoint was relapse rate; time to relapse and severity of disease were also studied. Kaplan-Meier estimates were calculated. RESULTS: Fifty-four patients (29 girls) entered the OSP (23 mild AD) and 49 (26 girls) continued into the DMP. Mean age was 5.5 (SD: 2.8) and 5.1 (SD: 2.3) yrs for FP and vehicle groups, respectively. Four patients withdrew from the DMP (two in every group). Patients treated with FP twice weekly had a 2.7 fold lower risk of experiencing a relapse than patients treated with vehicle (relative risk 2.72, SD: 1.28; p=0.034). FP was also superior to vehicle for delaying time to relapse. Both treatment therapies were well tolerated. CONCLUSION: This long-term study shows that twice weekly FP provides an effective maintenance treatment to control the risk of relapse in children with AD.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Dermatitis, Atopic/drug therapy , Fluticasone/therapeutic use , Secondary Prevention/methods , Child , Child, Preschool , Double-Blind Method , Female , Humans , Male
3.
Ross Fiziol Zh Im I M Sechenova ; 103(2): 161-71, 2017 Feb.
Article in Russian | MEDLINE | ID: mdl-30199197

ABSTRACT

Vibrissae loss associated with the peculiarities of the intragroup social interaction may be an important factor affecting the animals' performance in various behavioral tests. To evaluate the influence of spontaneous partial sensory deprivation as a consequence of the barbering activity of a cage mate, the battery of tests was conducted in male C57Bl/6N mice. The results indicate that the behavior of mice without vibrissae significantly differs from control animals in the tube, open field, social interaction and forced swim tests. Thus, the present findings suggest that vibrissae conditions have to be assessed before the inclusion of animals into experimental groups and/or further considered in data analysis.


Subject(s)
Behavior, Animal/physiology , Self Mutilation/psychology , Sensory Deprivation , Spatial Learning/physiology , Vibrissae/injuries , Animals , Male , Mice , Mice, Inbred C57BL , Research Design , Vibrissae/physiology
4.
Opt Lett ; 41(15): 3643-6, 2016 Aug 01.
Article in English | MEDLINE | ID: mdl-27472639

ABSTRACT

Digital pulse compression was used to enhance the performance of optical time-domain reflectometry, employing Brillouin dynamic gratings (BDGs) in polarization-maintaining fibers. The fundamental and unique issues in BDG field-reflection are addressed, and rules for proper selection of the coding and detection techniques are formulated. While coding in BDG applications generally requires coherent processing of the reflection, conditions are established for use of direct detection. A 256-bit Golay complementary unipolar probe code is used to demonstrate an eightfold signal-to-noise ratio enhancement in the measurement of the Brillouin gain spectrum (BGS), with a spatial resolution of 2 cm and a full-BGS acquisition rate of 133⅓ kHz, resulting in an equivalent reduction in the estimation error of small Brillouin frequency shifts.

5.
Zh Nevrol Psikhiatr Im S S Korsakova ; 115(4 Pt 2): 73-79, 2015.
Article in Russian | MEDLINE | ID: mdl-26288307

ABSTRACT

AIM: To adopt and validate the Straub tail reaction (SR) for comparative assessment of spastic effects of serotonergic compounds. MATERIAL AND METHODS: To measure the muscle relaxant activity, the morphine-induced Straub-tail assay was used. SR was graded according to modified intensity-score basis in a scale decribed by Kameyama et al. (1978). Subcutaneous injections of different doses of morphine (10-60 mg/kg) induced a dose-dependent SR with maximum response obtained 15-30 min after the morphine administration. RESULTS AND CONCLUSION: The centrally acting muscle relaxant baclofen (3-10 mg/kg) reduced SR induced by morphine (40 mg/kg) at all used doses; tizanidine decreased the intensity of SR at highest doses tested (0.6 and 1 mg/kg). Dantrolene (20-100 mg/kg), a peripherally acting muscle relaxant, did not affect SR. Effects of serotonergic agents depended on the specific mechanism of action. SR appears to be available for rapid evaluation of the effect of antispasticity drugs.

6.
Opt Lett ; 38(23): 5138-41, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24281529

ABSTRACT

Spontaneous Brillouin backscattering, which accompanies the operation of Brillouin dynamic gratings (BDGs) setups, is investigated both theoretically and experimentally. It is shown that this noisy emission, which cannot be separated from the signal of interest, contains not only the probe spontaneous Brillouin backscattering but also a significant contribution from the spontaneous/stimulated acoustic field, originating from the high-frequency writing pump. In the absence of the low-frequency writing pump and for a strong enough high-frequency writing pump, the observed Stokes noise can exhibit an average backscattered power much higher than that from the probe alone.

7.
Vet Comp Oncol ; 9(3): 183-95, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21848621

ABSTRACT

One of the main goals in cancer immunotherapy is the efficient activation of the host immune system against tumour cells. Dendritic cells (DCs) can induce specific anti-tumour immune responses in both experimental animal models and humans. However, most preclinical studies using small animal models show only limited correlation with studies carried out in clinical settings, whereas laboratory dogs naturally develop tumours that are biologically and histopathologically similar to their human counterparts. Here, we describe the generation and characterization of recombinant antibodies against canine DCs, isolated using the Tomlinson phage display system. We successfully isolated highly specific single-chain variable fragment (scFv) antibodies in a sequential three-step panning strategy involving depletion on canine peripheral blood mononuclear cells followed by positive selection on native canine DCs. This provides the basis for an antibody-based method for the immunological detection and manipulation of DCs and for monitoring antigen-specific immune responses.


Subject(s)
Dendritic Cells/immunology , Peptide Library , Recombinant Proteins/immunology , Amino Acid Sequence , Animals , Antibody Affinity , Antigens, CD34/immunology , Dogs , Female , Leukocytes, Mononuclear/immunology , Male , Molecular Sequence Data , Single-Chain Antibodies/immunology
8.
Br J Dermatol ; 163(2): 279-86, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20426788

ABSTRACT

BACKGROUND: Dysregulated, activated macrophages play a pivotal role in chronic inflammatory diseases such as arthritis and atopic dermatitis. These cells display increased expression of the high-affinity Fcgamma receptor (CD64), making them ideal targets for CD64-specific immunotoxins. We previously showed that a chemically linked immunotoxin, the monoclonal H22-RicinA, specifically eliminated infiltrating activated macrophages and resolved chronic cutaneous inflammation. However, several disadvantages are associated with classic immunotoxins, and we therefore followed a fusion protein strategy to express the antigen-binding site alone (scFv H22) fused to a derivative of Pseudomonas exotoxin A (ETA'). OBJECTIVES: To assess the potential effect of increased valency on efficacy, we produced monovalent [H22(scFv)-ETA'] and bivalent [H22(scFv)(2)-ETA'] versions and evaluated their potential for eliminating activated macrophages both in vitro and in vivo. METHODS: Both immunotoxins were produced by bacterial fermentation. Binding was assessed by flow cytometry on the monocytic CD64+ cell line U937. Toxicity was analysed by XTT and apoptosis induction by annexin V bioassay. The in vivo effect was tested in a human CD64 transgenic mouse model for cutaneous inflammation. RESULTS: The cytotoxic effects of both immunotoxins were clearly due to apoptosis with an IC(50) of 140 pmol L(-1) for monovalent and only 14 pmol L(-1) for the divalent version. In vivo treatment with H22(scFv)-ETA' reduced CD64+ activated macrophages to 21% of their initial numbers whereas H22(scFv)(2)-ETA' treatment reduced these cells to 4.8% (P < 0.001). CONCLUSIONS: These data clearly show increased efficacy due to increased valency of the anti-CD64 immunotoxin. Both recombinant immunotoxins have a low IC(50), making them suitable for the treatment of diseases involving dysregulated, activated macrophages.


Subject(s)
Exotoxins/pharmacology , Immunotoxins/pharmacology , Inflammation/physiopathology , Macrophages/immunology , Receptors, IgG/immunology , Skin Diseases/drug therapy , Animals , Apoptosis/drug effects , Chronic Disease , Disease Models, Animal , Exotoxins/immunology , Humans , Immunoglobulin Fragments/immunology , Immunoglobulin Fragments/pharmacology , Immunotoxins/chemistry , Immunotoxins/immunology , Macrophages/drug effects , Mice , Mice, Transgenic , Recombinant Fusion Proteins/immunology , Recombinant Fusion Proteins/pharmacology , Skin Diseases/immunology
9.
Curr Pharm Des ; 15(23): 2700-11, 2009.
Article in English | MEDLINE | ID: mdl-19689340

ABSTRACT

Immunotoxins (ITs) are protein-based drugs combining a target-specific binding domain (usually derived from an antibody) and a cytotoxic domain to kill target cells. They are among the most promising new therapeutic tools to fight cancer, and several clinical trials have been completed with encouraging results. Although the targeted elimination of malignant cells is an elegant concept, there are numerous practical challenges that limit the clinical use of ITs, including inefficient cellular uptake, low cytotoxicity and off-target effects. Here we present some of the strategies that have been developed to improve the efficacy of ITs, particularly those involving the incorporation of functional peptide sequences into recombinant ITs to improve target binding, modify plasma half life and distribution, boost tumor penetration, enhance cellular uptake and increase cytotoxic efficiency.


Subject(s)
Antineoplastic Agents/administration & dosage , Drug Delivery Systems/methods , Immunotoxins/administration & dosage , Recombinant Proteins/administration & dosage , Recombinant Proteins/biosynthesis , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Binding Sites, Antibody/immunology , Cell Death/drug effects , Humans , Immunotoxins/pharmacokinetics , Immunotoxins/pharmacology , Models, Biological , Models, Immunological , Recombinant Proteins/pharmacokinetics , Recombinant Proteins/pharmacology
10.
Curr Pharm Des ; 15(23): 2712-8, 2009.
Article in English | MEDLINE | ID: mdl-19689341

ABSTRACT

Immunotoxins are powerful tools to specifically eliminate deviated cells. Due to the side effects of the original immunotoxins, they were only considered for the treatment of cancer as in these cases, the potential favourable effect outweighed the unwanted toxic side effects. Over time, many improvements in the construction of immunotoxins have been implemented that circumvent, or at least strongly diminish, the side effects. In consequence this opens the way to employ these immunotoxins for the treatment of non-life threatening diseases. One such category of disease could be the many chronic inflammatory disorders in which an uncontrolled interaction between inflammatory cells leads to chronicity. In several of these chronic conditions, activated macrophages, which are characterised by an increased expression of CD64, are known to play a key role. In this review we discuss the data presently available on elimination of activated macrophages through CD64 immunotoxins in several animal models for chronic disease. A chemically linked complete antibody with the plant toxin Ricin-A, proved very effective and provided proof of concept. Subsequently, the development towards genetically engineered, fully human, multivalent single chain based immunotoxins that have diminished immunogenicity, is discussed. The data show that the specific elimination of activated macrophages through CD64 is indeed beneficial for the course of disease. As opposed to other methods used to inactivate or eliminate macrophages, with the CD64 based immunotoxins only the activated population is killed. This may open the way to apply these immunotoxins as therapeutics in chronic inflammatory disease.


Subject(s)
Drug Delivery Systems/methods , Immune System Diseases/drug therapy , Immunotoxins/therapeutic use , Inflammation/drug therapy , Receptors, IgG/drug effects , Animals , Humans , Leukemia, Myeloid, Acute/drug therapy , Macrophage Activation/drug effects , Macrophage Activation/immunology , Monocytes/drug effects , Monocytes/immunology , Monocytes/metabolism , Receptors, IgG/immunology , Receptors, IgG/metabolism , Recombinant Proteins/biosynthesis , Recombinant Proteins/therapeutic use
11.
An Pediatr (Barc) ; 69(6): 515-20, 2008 Dec.
Article in Spanish | MEDLINE | ID: mdl-19128763

ABSTRACT

INTRODUCTION: Acute gastroenteritis (AGE) in infants has a significant impact on the quality of life of their parents. MATERIAL AND METHODS: Cross-sectional study on the sociological family impact related to rotavirus AGE in children under 2 years. The study was carried out in 25 hospitals and 5 primary care centres in Spain. Sociodemographic, epidemiological and clinical data were recorded, as well as the symptomatology of AGE and its severity measured by the Clark scale. Stool samples were tested to determine rotavirus positive (RV+) or negative (RV-). The parents were asked to complete a a family impact questionnaire. RESULTS: Stool specimens were tested in 1087 AGE cases (584 RV+ vs 503 RV-). The 99.5 % of parents whose children were RV+ reported more worries vs. the 97.7 % of RV-, and RV+ had a higher importance score (p < 0.05). A higher percentage of RV+ parents and those with a high importance score reported more time dedicated to dehydration treatment (p < 0.05). The 82.5 % vs. 73.9 % had disruption of their household tasks, with more importance scores (p < 0.05). RV+ had a higher percentage and importance score than RV- ones in all aspects of their child's AGE symptoms, except loss of appetite. CONCLUSION: AGE produces important dysfunctional experiences in daily family life. According to parental perceptions, RV+ produces greater worries and dysfunctions in child behaviour.


Subject(s)
Family Health , Gastroenteritis/virology , Rotavirus Infections , Cross-Sectional Studies , Humans , Infant
12.
Phys Rev Lett ; 99(16): 161603, 2007 Oct 19.
Article in English | MEDLINE | ID: mdl-17995237

ABSTRACT

In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n', could potentially mix and undergo nn' oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the n' amplitude in the n wave function and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time taunn' > 103 s (95% C.L.) is derived.

13.
Opt Express ; 13(11): 4090-5, 2005 May 30.
Article in English | MEDLINE | ID: mdl-19495320

ABSTRACT

We observe distinct variations between the DGD temporal statistics for different channels in a field installed system. This phenomenon is confirmed with statistical analysis, using a model in which DGD dynamics are due only to a finite number of active points along the link.

14.
Int J Mol Med ; 14(4): 729-35, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15375609

ABSTRACT

The display of recombinant antibody fragments on the surface of filamentous phage mimicks B cells and is therefore a technology ideal to generate antibodies against any potential target antigen in vitro. In order to obtain tumor specific, high-affinity single chain antibody fragments (scFv), it has been speculated that lymph node tissue from cancer patients infiltrated with activated B cells must be a valuable source of antibody V-genes. The aim of this study was to generate a human scFv-phage library from lymph nodes of patients with breast cancer and to develop a stringent depletion and selection protocol in order to isolate specific single chain antibodies recognizing potentially new antigens in breast cancer. The amplification of the V-genes cloned from regional lymph node tissue and their assembly to single chain variable fragments was optimized in terms of library size and diversity. A large set of degenerated primers, annealing to all known V-gene families, was designed and used under optimized PCR conditions. The amplified V-genes were genetically fused in all possible combinations and cloned into a phagemid vector. Depletion and selection on mammary epithelial and primary breast carcinoma cell lines, respectively led to the isolation of a breast cancer cell line specific scFv (BCK-1 scFv) from this patient-derived scFv-phage display library as demonstrated in polyclonal and monoclonal ELISA, using immobilized cell membrane fractions of the indicated cell lines. A new recombinant breast cancer cell line specific antibody based on V-genes derived from reactive B-lymphocyte-infiltrated lymph nodes of patients with breast cancer was isolated via phage display, performing stringent depletion and selection protocols. We believe that this combination of antibody V-gene source and elaborated phage display depletion and selection strategy will be successful for the retrieval of numerous other recombinant, tumor specific antibody fragments.


Subject(s)
Antibodies/immunology , Antigens, Neoplasm/immunology , Breast Neoplasms/immunology , Immunoglobulin Variable Region/immunology , Lymph Nodes/immunology , Lymph Nodes/metabolism , Peptide Library , Amino Acid Sequence , Antibodies/chemistry , Antibodies/genetics , Antibody Specificity , Base Sequence , Cell Line, Tumor , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin Variable Region/chemistry , Immunoglobulin Variable Region/genetics , Molecular Sequence Data , Sensitivity and Specificity
15.
Rev Med Interne ; 25(2): 150-3, 2004 Feb.
Article in French | MEDLINE | ID: mdl-14744647

ABSTRACT

INTRODUCTION: Homocystinuria due to cystathionine beta synthase (CBS) deficiency is a special type of hyperhomocysteinemia because of its clinical expression (thrombotic events, ectopic lens and mental retardation). It's a rare, hereditary recessive autosomic disease generally diagnosed during childhood. EXEGESIS: Thrombophilia examination in a 50-year-old man found a dramatically increase homocysteinemia. Homocystinuria, profile of plasmatic amino acids and reduced CBS activity, (0.05 microkat/kg protein; N = 1.5 +/- 0.8) confirmed homocystinuria's diagnosis. Family study demonstrates that three siblings suffer from homocystinuria. Vitamin enriched diet with pyridoxin, vitamin B12 and folates induced reducing hyperhomocysteinemia and homocystinuria. CONCLUSION: This case report, original because of the diagnosis age, suggests a hyperhomocysteinemia's screening in patients with recurrent thrombotic events.


Subject(s)
Cystathionine beta-Synthase/deficiency , Homocystinuria/diagnosis , Diagnosis, Differential , Humans , Male , Middle Aged , Thrombophilia/etiology , Time Factors
17.
Ann Hematol ; 81(5): 258-66, 2002 May.
Article in English | MEDLINE | ID: mdl-12029535

ABSTRACT

New therapeutic approaches for the treatment of B-cell chronic lymphocytic leukemia (B-CLL) can induce remarkable responses. Molecular remissions have been observed occasionally after high-dose chemotherapy. Thus, new improved techniques to monitor residual tumor cells on a molecular basis in CLL are warranted. For this purpose, a real-time quantitative allele-specific oligonucleotide polymerase chain reaction (ASO-PCR) for patients with B-CLL was designed. In the present study, the PCR assay was standardized with identical cycling parameters as well as primer, probe, and MgCl(2) concentration for each patient. Ten patients were monitored with DNA samples obtained at 52 time points (median: 5.2 per patient). The median follow-up per patient was 11.4 months. Nine of ten patients had PCR-detectable residual tumor cells in the peripheral blood after therapy. One patient became PCR negative with a combination of fludarabine and rituximab after the end of treatment. The MRD levels in patients with detectable disease ranged from 0.002% to 10.1% after therapy. We conclude that real-time quantitative ASO-PCR can be utilized for quantitative molecular monitoring of minimal residual disease (MRD) in B-CLL patients in complete remission (CR), that new effective treatment approaches such as combined chemo/immunotherapy can render CLL patients PCR negative, and that different MRD levels in PCR-positive patients were observed warranting further investigation into possible correlation with clinical outcome.


Subject(s)
Leukemia, Lymphocytic, Chronic, B-Cell/metabolism , Leukemia, Lymphocytic, Chronic, B-Cell/pathology , Neoplasm, Residual/pathology , Neoplastic Cells, Circulating/pathology , Polymerase Chain Reaction/methods , Vidarabine/analogs & derivatives , Aged , Alleles , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Murine-Derived , Antineoplastic Agents/therapeutic use , Computer Systems , DNA, Neoplasm/analysis , Female , Humans , Immunoglobulin Heavy Chains/genetics , Leukemia, Lymphocytic, Chronic, B-Cell/drug therapy , Leukemia, Lymphocytic, Chronic, B-Cell/genetics , Male , Middle Aged , Rituximab , Vidarabine/therapeutic use
18.
Cancer Res ; 61(24): 8737-42, 2001 Dec 15.
Article in English | MEDLINE | ID: mdl-11751393

ABSTRACT

A number of different immunotoxins composed of cell-specific targeting structures coupled to plant or bacterial toxins have increasingly been evaluated for immunotherapy. Because these foreign proteins are highly immunogenic in humans, we have developed a new CD30 ligand-based fusion toxin (Ang-CD30L) using the human RNase angiogenin. The completely human fusion gene was inserted into a pET-based expression plasmid. Transformed Escherichia coli BL21(DE3) were grown under osmotic stress conditions in the presence of compatible solutes. After isopropyl beta-D-thiogalactoside induction, the M(r) 37,000 His(10)-tagged Ang-CD30L was directed into the periplasmic space and functionally purified by a combination of metal ion affinity followed by enterokinase cleavage of the His(10)-Tag and molecular size chromatography. The characteristics of the recombinant protein were assessed by ELISA, flow cytometry, and toxicity assays showing specific activity against CD30(+) Hodgkin-derived cells. Specific binding activity of Ang-CD30L was verified by competition with anti-CD30 monoclonal antibody Ki-4 and commercially available CD30L-CD8 chimeric protein. Ang-CD30L showed RNase activity in vitro. The human recombinant immunotoxin showed significant toxicity toward several CD30-positive cell lines (HDLM-2, L1236, KM-H2, and L540Cy) and exhibited highest cytotoxicity against L540 cells (IC(50) = 8 ng/ml) as determined by cell proliferation assays. CD30 specificity was confirmed by competitive toxicity assays. This is the first report on the specific cytotoxicity of a recombinant completely human fusion toxin with possibly largely reduced immunogenicity for the treatment of CD30-positive malignancies.


Subject(s)
Hodgkin Disease/drug therapy , Immunotoxins/pharmacology , Ki-1 Antigen/metabolism , Membrane Glycoproteins/pharmacology , Recombinant Fusion Proteins/pharmacology , Ribonuclease, Pancreatic/pharmacology , CD30 Ligand , Cloning, Molecular , Hodgkin Disease/immunology , Hodgkin Disease/metabolism , Humans , Immunotoxins/genetics , Immunotoxins/metabolism , Ki-1 Antigen/immunology , Membrane Glycoproteins/genetics , Membrane Glycoproteins/metabolism , Plasmids/genetics , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism , Ribonuclease, Pancreatic/genetics , Ribonuclease, Pancreatic/metabolism , Ribonucleases/metabolism , Tumor Cells, Cultured
19.
Int J Mol Med ; 8(5): 579-84, 2001 Nov.
Article in English | MEDLINE | ID: mdl-11605031

ABSTRACT

Since the disialoganglioside GD2 is abundantly present on the surface of neuroblastoma cells, we constructed a new recombinant immunotoxin for possible clinical use in patients with neuroblastoma. A functional 14.18 scFv-phage was obtained by selection of an anti-GD2 hybridoma derived phage antibody mini-library on the neuroblastoma-derived, GD2-expressing cell line IMR5. By insertion into the bacterial expression vector pBM1.1 the selected scFv was fused to a deletion mutant of Pseudomonas exotoxin A (ETA'). Periplasmically expressed 14.18(scFv)-ETA' bound to the GD2 expressing cell line IMR5, but not to the GD2 negative Hodgkin-derived cell line L540Cy as documented by ELISA and flow cytometry. The recombinant immunotoxin (rIT) inhibited cell viability of IMR5 cells by 50% at concentrations (IC(50)) of 0.326 microg/ml. This recombinant immunotoxin will be further investigated in vivo for its value as a new immunotherapeutic agent for the treatment of patients with neuroblastoma.


Subject(s)
ADP Ribose Transferases , Antibodies, Monoclonal/pharmacology , Bacterial Toxins , Gangliosides/immunology , Immunoglobulin Fragments/pharmacology , Immunotoxins/pharmacology , Neuroblastoma/drug therapy , Virulence Factors , Antibodies, Monoclonal/genetics , Binding, Competitive , Cell Membrane/metabolism , Cell Survival/drug effects , Cell Survival/immunology , Cloning, Molecular , Cytotoxicity, Immunologic , Dose-Response Relationship, Drug , Exotoxins/genetics , Humans , Immunoglobulin Fragments/genetics , Immunoglobulin Fragments/metabolism , Immunoglobulin Variable Region/genetics , Immunotoxins/genetics , Immunotoxins/isolation & purification , Neuroblastoma/immunology , Protein Binding , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/pharmacology , Tumor Cells, Cultured/drug effects , Tumor Cells, Cultured/immunology , Pseudomonas aeruginosa Exotoxin A
20.
Biotechniques ; 30(2): 404-8, 410, 412-3, 2001 Feb.
Article in English | MEDLINE | ID: mdl-11233610

ABSTRACT

Display of functional antibody fragments on the surface of filamentous bacteriophages allows fast selection of specific phage antibodies against a variety of target antigens. However, enrichment of single chain variable fragment (scFv)-displaying phages is often hampered by the abundance of bacteriophages lacking antibody fragments. Moderate adhesive binding activities and production advantages of these "empty" phages results in their subsequent enrichment during selection on target cells. To date, very limited effort has been made to develop strategies removing nonspecific binding phages during the selection processes. To efficiently reduce insert-free phages when panning on intact cells, we increased the washing stringency by lowering the pH of the buffer with citric acid. Under standard washing procedures (pH 7.4), only approximately 73% of recovered phages were insert-free after three rounds of selection. Using stringent washing procedures (pH 5.0), approximately 12% of recovered phages contained no scFv. Using this protocol, we have cloned an antibody fragment from a mouse/human hybridoma cell line directed against the disialoganglioside GD2. This study confirms that selection of phage antibodies on cells is efficiently enhanced by assays augmenting the stringency to remove nonspecific binding phages.


Subject(s)
Immunoglobulin Fragments/genetics , Peptide Library , Enzyme-Linked Immunosorbent Assay , Humans , Hydrogen-Ion Concentration , Tumor Cells, Cultured
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