scholarly journals The immunogenicity of chimeric antibodies.

1989 ◽  
Vol 170 (6) ◽  
pp. 2153-2157 ◽  
Author(s):  
M Brüggemann ◽  
G Winter ◽  
H Waldmann ◽  
M S Neuberger
Keyword(s):  
The Self ◽  
Chimeric Antibody ◽  
Human Origin ◽  
Strong Response ◽  
Chimeric Antibodies ◽  
V Region

Mice were immunized with model xenogeneic (both the VH frameworks and the CH domains of human origin), chimeric (just VH frameworks human), or self antibodies, and the antiantibody responses were dissected. Only the self antibody did not elicit a response. A strong response was elicited by the most xenogeneic antibody with approximately 90% against the C and approximately 10% against the V. The anti-V response was not attenuated in the chimeric antibody, demonstrating that foreign VH frameworks can be sufficient to lead to a strong antiantibody response. The magnitude of this xenogeneic anti-VH response was similar to that of the allotypic response elicited by immunizing mice of the Igha allotype with an Ighb antibody. Thus, although chimerization can diminish antiantibody responses, attention should be paid both to V region immunogenicity and to polymorphism.

Molecular engineering: applications to the clinical laboratory

1993 ◽  
Vol 39 (9) ◽  
pp. 1988-1997
Author(s):  
R G Hamilton
Keyword(s):  
Clinical Laboratory ◽  
Genetically Engineered ◽  
Molecular Engineering ◽  
Total Serum ◽  
Chimeric Antibody ◽  
Human Igg ◽  
Chimeric Antibodies ◽  
Human Igg1 ◽  
V Region ◽  
Volume Estimates

Abstract Advances in cellular and molecular biology methods have led to the molecular engineering of novel human biomolecules, some of which have been successfully applied to the documentation of clinical laboratory assays. Here I describe the use of engineered chimeric antibodies in the clinical immunology laboratory in three principal applications: (a) as reference proteins to document the specificity of clinical assay reagents, be used as reagent-grade purified antigens, and facilitate the epitope mapping of antibody reagents; (b) as calibration proteins to assign mass/volume estimates to proposed antibody standards; and (c) as interference proteins to study the effects of naturally occurring autoantibodies on the accuracy and sensitivity of current clinical assays. The model recombinant proteins used for these illustrations are chimeric antibodies with a defined V-region specificity for one of two haptens (nitrophenyl or dansyl) and C-region domains covering a spectrum of human isotypes. I also describe a panel of mutant human IgG1-4 anti-dansyl chimeric antibodies that have been genetically engineered with swapped, deleted, or point-mutated wild-type C-region exons and used as specialized reagents for mapping the epitopes to which clinically used human IgG-specific monoclonal antibodies bind. Finally, the use of a recombinant human IgG1 anti-human IgE Fc chimeric antibody to simulate human IgG anti-IgE autoantibody interference in assays of total serum IgE is investigated.

scholarly journals Recombinant Mouse-Human Chimeric Antibodies as Calibrators in Immunoassays That Measure Antibodies toToxoplasma gondii

1998 ◽  
Vol 36 (5) ◽  
pp. 1277-1284 ◽  
Author(s):  
John Hackett ◽  
Jane Hoff-Velk ◽  
Alan Golden ◽  
Jeff Brashear ◽  
John Robinson ◽  
...  
Keyword(s):  
Human Plasma ◽  
High Titer ◽  
Variable Region ◽  
Immunoglobulin M ◽  
Expression Vectors ◽  
Chimeric Antibody ◽  
Chimeric Mouse ◽  
Variable Regions ◽  
Chimeric Antibodies ◽  
Igg1 Antibody

In the present study, we examined the feasibility of using recombinant antibodies containing murine variable regions and human constant regions as calibrators or controls in immunoassays. As a model system, we chose the Abbott IMx Toxo immunoglobulin M (IgM) and Toxo IgG assays designed to detect antibodies to Toxoplasma gondii. Two mouse monoclonal antibodies were selected based on their reactivity to the T. gondii antigens P30 and P66. Heavy- and light-chain variable-region genes were cloned from both hybridomas and transferred into immunoglobulin expression vectors containing human kappa and IgG1 or IgM constant regions. The constructs were stably transfected into Sp2/0-Ag14 cells. In the IMx Toxo IgG assay, immunoreactivity of the anti-P30 chimeric IgG1 antibody paralleled that of the positive human plasma-derived assay calibrators. Signal generated with the anti-P66 chimeric IgG1 antibody was observed to plateau below the maximal reactivity observed for the assay calibrator. Examination of the IgM chimeric antibodies in the IMx Toxo IgM assay revealed that both the anti-P30 and anti-P66 antibodies matched the assay index calibrator manufactured with human Toxo IgM-positive plasma. When evaluated with patient samples, the correlation between results obtained with the chimeric antibody calibrators and the positive human plasma calibrators was ≥0.985. These data demonstrate that chimeric mouse-human antibodies are a viable alternative to high-titer positive human plasma for the manufacture of calibrators and controls for diagnostic assays.

scholarly journals Construction and Characterization of 1F5 Chimeric Anti-CD20 Monoclonal Antibodies: an Efficient Splicing by Overlap Extension-polymerase Chain Reaction Technique

2021 ◽  
Author(s):  
Fatemeh Khademi ◽  
Pantea Mohammadi ◽  
Ali Mostafaei
Keyword(s):  
Polymerase Chain Reaction ◽  
Cell Viability ◽  
B Cell Lymphoma ◽  
Chimeric Antibody ◽  
Chimeric Mouse ◽  
Chain Reaction ◽  
Chimeric Antibodies ◽  
Overlap Extension ◽  
Polymerase Chain ◽  
Anti Cd20

Despite the unparalleled success of anti-CD20-targeted immunotherapy, the currently available mAbs are not sufficiently efficacious in the treatment of lymphoma. 1F5 is one of a panel of anti-CD20 mAbs that was used in the B-cell lymphoma serotherapy. Despite the efficacy of murine 1F5 mAbs in lymphoma patients, the 1F5 chimeric antibodies with human effector functionality are yet to be approved and widely used in the treatment of lymphoma. In this study, the conversion of 1F5 mAb from mouse IgG2a to human-mouse chimeric IgG1 was achieved and the chimeric antibody was partially characterized. We constructed the 1F5 chimeric mouse-human anti-CD20 antibody genes using an efficient Splicing by overlap extension-polymerase chain reaction (SOE-PCR) technique and cloned the chimeric heavy and light genes in pBudCE4.1 mammalian expression vector, followed by purification of the expressed chimeric 1F5 mAbs using affinity chromatography. Our investigation also included the biological properties of purified chimeric antibodies. The generated 1F5 chimeric mAbs mediate complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC) against Raji and Daudi Burkitt's lymphoma cell lines, which were comparable with rituximab and exhibit superior reduction in cell viability in vitro, compared to rituximab. The current study indicated that the generated chimeric 1F5 mAbs has potential CDC and ADCC activity which was comparable with rituximab whereas it exhibits a superior reduction in cell viability, compared to rituximab. Our work contributes to future studies involving in vivo biological functions and the application of the 1F5 chimeric antibody.

scholarly journals Lymphokine-activated killer cells from normal and lymphoma subjects are cytotoxic for cells coated with antibody derivatives displaying human Fc gamma

Blood ◽  
1988 ◽  
Vol 72 (6) ◽  
pp. 1985-1991
Author(s):  
RJ Dearman ◽  
FK Stevenson ◽  
M Wrightham ◽  
TJ Hamblin ◽  
MJ Glennie ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Lak Cells ◽  
Chimeric Antibody ◽  
Normal Donor ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Lymphokine Activated Killer Cells ◽  
Chimeric Antibodies ◽  
Human Lymphoma ◽  
Antibody Derivatives

Lymphokine-activated killer (LAK) cells were successfully generated in all cases from blood mononuclear cells obtained from six patients with lymphoma. The LAK cells from three of these patients and from five normal adult donors were tested for their effector abilities in antibody-dependent cellular cytotoxicity (ADCC) against guinea pig leukemic lymphocytes coated with various antiidiotype antibodies. Cells from all the donors behaved similarly. Mouse monoclonal antibodies of IgG1, IgG2a, and IgG2b isotypes invoked no ADCC. However, substantial ADCC was invoked by the chimeric antibody FabFc, in which Fab'gamma from mouse antiidiotype is thioether-bonded to human normal Fc gamma. Similar results were obtained on testing LAK cells from a normal donor against uncultured human lymphoma targets coated with native or chimeric antiidiotype. The ADCC invoked by the mouse-human chimeric antibodies appears to depend on the human Fc gamma they display and not on the univalency of the derivatives used. The findings imply that LAK technology could usefully augment serotherapy that uses antibody derivatives displaying human Fc gamma.

scholarly journals USING OF UNIVERSAL PLASMID CONSTRUCTIONS FOR DESIGN OF RECOMBINANT ANTIBODIES WITH DEFINED SPECIFICITY IN EUKARYOTIC CELLS

2019 ◽  
Vol 1 (3) ◽  
pp. 32-39
Author(s):  
T. G. Samartseva ◽  
A. S. Oksanich ◽  
N. F. Gavrilova ◽  
I. V. Yakovleva ◽  
V. V. Sviridov ◽  
...  
Keyword(s):  
Cho Cells ◽  
Variable Region ◽  
Chimeric Antibody ◽  
Antibody Activity ◽  
Antigen Specificity ◽  
Minimum Concentration ◽  
Variable Regions ◽  
Chimeric Antibodies ◽  
Recombinant Plasmids ◽  
Heavy Chains

Aim. In this study we aimed to develop the methodology to change the antigen specificity of chimeric antibodies by replacing the variable region genes in the previously designed universal plasmid constructions pLK DT-17 and pHG DT-17 encoding the DT-17 antibody against the diphtheria toxin (DT) to the genes of antibody binding to another DT epitope — DT-22.Materials and methods. The genes of the light and heavy chain variable regions of mouse anti-DT antibodies — DT-22 were amplified from the hybridoma producing monoclonal antibodies to DT by reverse transcription and PCR methods. Genetic engineering methods were used to replace the variable regions of DT-17 antibody in the recombinant plasmids pLK DT-17 and pHG DT-17 encoding the light and heavy chains of DT-17 antibody, respectively to the relevant genes of DT-22. Subsequently, a «supervector» pSV DT-22, containing the genes of both chains of the chimeric antibody, was designed. CHO cells were transfected with a «supervector» and a highly productive clone, secreting chimeric antibodies to DT was obtained. Immunochemical and cultural methods were used to evaluate antibody activity. The affinity chromatography was used to purified preparative amounts of antibodies.Results. The yield of purified secreted chimeric DT-22 antibodies was 4 mg from per liter of culture medium. The minimum concentration of chimeric antibodies at which DT was neutralized in the CHO cells was 22 μg/mL of medium.Conclusion. Thus it has been shown how to generate new vector coding synthesis of light and heavy chains of a chimeric DT-22 antibody specific to another DT epitope using previously constructed universal recombinant plasmids pLK DT-17 and pHG DT-17 encoding, light and heavy chains of antibodies against DT DT-17, respectively.

scholarly journals Lymphokine-activated killer cells from normal and lymphoma subjects are cytotoxic for cells coated with antibody derivatives displaying human Fc gamma

Blood ◽  
1988 ◽  
Vol 72 (6) ◽  
pp. 1985-1991 ◽  
Author(s):  
RJ Dearman ◽  
FK Stevenson ◽  
M Wrightham ◽  
TJ Hamblin ◽  
MJ Glennie ◽  
...  
Keyword(s):  
Mononuclear Cells ◽  
Lak Cells ◽  
Chimeric Antibody ◽  
Normal Donor ◽  
Cellular Cytotoxicity ◽  
Antibody Dependent Cellular Cytotoxicity ◽  
Lymphokine Activated Killer Cells ◽  
Chimeric Antibodies ◽  
Human Lymphoma ◽  
Antibody Derivatives

Abstract Lymphokine-activated killer (LAK) cells were successfully generated in all cases from blood mononuclear cells obtained from six patients with lymphoma. The LAK cells from three of these patients and from five normal adult donors were tested for their effector abilities in antibody-dependent cellular cytotoxicity (ADCC) against guinea pig leukemic lymphocytes coated with various antiidiotype antibodies. Cells from all the donors behaved similarly. Mouse monoclonal antibodies of IgG1, IgG2a, and IgG2b isotypes invoked no ADCC. However, substantial ADCC was invoked by the chimeric antibody FabFc, in which Fab'gamma from mouse antiidiotype is thioether-bonded to human normal Fc gamma. Similar results were obtained on testing LAK cells from a normal donor against uncultured human lymphoma targets coated with native or chimeric antiidiotype. The ADCC invoked by the mouse-human chimeric antibodies appears to depend on the human Fc gamma they display and not on the univalency of the derivatives used. The findings imply that LAK technology could usefully augment serotherapy that uses antibody derivatives displaying human Fc gamma.

scholarly journals In Silico Analyses on the Comparative Potential of Therapeutic Human Monoclonal Antibodies Against Newly Emerged SARS-CoV-2 Variants Bearing Mutant Spike Protein

2022 ◽  
Vol 12 ◽  
Author(s):  
Nabarun Chandra Das ◽  
Pritha Chakraborty ◽  
Jagadeesh Bayry ◽  
Suprabhat Mukherjee
Keyword(s):  
Monoclonal Antibodies ◽  
In Silico ◽  
Spike Protein ◽  
Economic Losses ◽  
Chimeric Antibody ◽  
Stable Complex ◽  
Human Monoclonal Antibodies ◽  
Chimeric Antibodies ◽  
In Silico Analyses ◽  
Potential Use

Since the start of the pandemic, SARS-CoV-2 has already infected more than 250 million people globally, with more than five million fatal cases and huge socio-economic losses. In addition to corticosteroids, and antiviral drugs like remdesivir, various immunotherapies including monoclonal antibodies (mAbs) to S protein of SARS-CoV-2 have been investigated to treat COVID-19 patients. These mAbs were initially developed against the wild-type SARS-CoV-2; however, emergence of variant forms of SARS-CoV-2 having mutations in the spike protein in several countries including India raised serious questions on the potential use of these mAbs against SARS-CoV-2 variants. In this study, using an in silico approach, we have examined the binding abilities of eight mAbs against several SARS-CoV-2 variants of Alpha (B.1.1.7) and Delta (B.1.617.2) lineages. The structure of the Fab region of each mAb was designed in silico and subjected to molecular docking against each mutant protein. mAbs were subjected to two levels of selection based on their binding energy, stability, and conformational flexibility. Our data reveal that tixagevimab, regdanvimab, and cilgavimab can efficiently neutralize most of the SARS-CoV-2 Alpha strains while tixagevimab, bamlanivimab, and sotrovimab can form a stable complex with the Delta variants. Based on these data, we have designed, by in silico, a chimeric antibody by conjugating the CDRH3 of regdanivimab with a sotrovimab framework to combat the variants that could potentially escape from the mAb-mediated neutralization. Our finding suggests that though currently available mAbs could be used to treat COVID-19 caused by the variants of SARS-CoV-2, better results could be expected with the chimeric antibodies.

scholarly journals PLASMID DESIGN FOR PRODUCTION OF CHIMERIC ANTIBODIES WITH DEFINED SPECIFICITY IN EUKARYOTES

2017 ◽  
pp. 56-63 ◽  
Author(s):  
A. S. Oksanich ◽  
T. G. Samartseva ◽  
E. B. Faizjuloev ◽  
N. F. Gavrilova ◽  
I. V. Yakovleva ◽  
...  
Keyword(s):  
Cho Cells ◽  
Diphtheria Toxin ◽  
Culture Medium ◽  
Variable Region ◽  
Plasmid Vector ◽  
Chimeric Antibody ◽  
Antibody Activity ◽  
Minimum Concentration ◽  
Chimeric Antibodies ◽  
Heavy Chains

Aim. In this study we aimed to design the universal genetic construction expressing the light and heavy chains of a chimeric antibody, to develop methodological approaches for the production of chimeric antibodies with defined specificity using the monoclonal antibodies to diphtheria toxin (DT) DT-17 in the CHO cells as an example and to evaluate their immunochemical and effector properties. Materials and methods. Variable region genes of the light and heavy chains of mouse antibodies DT-17 to diphtheria toxin were obtained by PCR method and cloned into pCI-neo plasmid vector. The S V DT -17neo «supervector» containing the genes of a chimeric antibody was constructed by using of genetic engineering techniques. CHO cells were transfected with «supervector» and a highly productive clone secreting chimeric antibodies to DT were collected. Immunochemical methods were used to evaluate antibody activity, and affinity chromatography was used to prepare preparative amounts of the antibodies. Results. U ni versal vectors pLK DT -17 and pHG DT-17 containing light and heavy chain genes of the chimeric antibodies DT -17 to DT were constructed. The variable and constant region genes were flanked by endonuclease restriction sites, which allows to change the specificity of the antibodies. In the future it will make possible to study the modifications of the class and species specificity of the chimeric immunoglobulins. When the CHO cell culture was transfected with the designed vectors, the accumulation of antibodies to DT in the culture medium was detected. The yield of purified DT-17 chimeric antibodies was 4 mg per 1 liter of culture medium. The minimum concentration of chimeric antibodies necessary for DT neutralization in the CHO cells was 30 pg/mL. Conclusion. Universal plasmids encoding the synthesis of light and heavy chains of chimeric DT -17 antibody have been designed. On the basis of these vectors, a «supervector» and a highly productive clone secreting specific antibodies that had neutralizing activity against DT were obtained.

Problem behavior in autism spectrum disorders: A paradigmatic self-organized perspective of network structures

2019 ◽  
Vol 42 ◽  
Author(s):  
Lucio Tonello ◽  
Luca Giacobbi ◽  
Alberto Pettenon ◽  
Alessandro Scuotto ◽  
Massimo Cocchi ◽  
...  
Keyword(s):  
Autism Spectrum Disorder ◽  
Problem Behaviors ◽  
Autism Spectrum ◽  
The Self ◽  
Network Structures ◽  
Self Organized ◽  
Critical Equilibrium ◽  
Self Organized Criticality ◽  
Acute Agitation ◽  
Spectrum Disorders

AbstractAutism spectrum disorder (ASD) subjects can present temporary behaviors of acute agitation and aggressiveness, named problem behaviors. They have been shown to be consistent with the self-organized criticality (SOC), a model wherein occasionally occurring “catastrophic events” are necessary in order to maintain a self-organized “critical equilibrium.” The SOC can represent the psychopathology network structures and additionally suggests that they can be considered as self-organized systems.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

Sign in / Sign up

Export Citation Format

Share Document