scholarly journals Characterization of Entamoeba histolytica Intermediate Subunit Lectin-Specific Human Monoclonal Antibodies Generated in Transgenic Mice Expressing Human Immunoglobulin Loci

2008 ◽  
Vol 77 (1) ◽  
pp. 549-556 ◽  
Author(s):  
Hiroshi Tachibana ◽  
Xun-Jia Cheng ◽  
Hideo Tsukamoto ◽  
Johbu Itoh
Keyword(s):  
Monoclonal Antibodies ◽  
Transgenic Mice ◽  
Entamoeba Histolytica ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Significant Inhibition ◽  
Human Immunoglobulin ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Healthy Humans

ABSTRACT Four fully human monoclonal antibodies (MAbs) to Entamoeba histolytica intermediate subunit lectin (Igl) were prepared in XenoMouse mice, which are transgenic mice expressing human immunoglobulin loci. Examination of the reactivities of these MAbs to recombinant Igl1 and Igl2 of E. histolytica showed that XEhI-20 {immunoglobulin G2(κ) [IgG2(κ)]} and XEhI-28 [IgG2(κ)] were specific to Igl1, XEhI-B5 [IgG2(κ)] was specific to Igl2, and XEhI-H2 [IgM(κ)] was reactive with both Igls. Gene analyses revealed that the VH and VL germ lines were VH3-48 and L2 for XEhI-20, VH3-21 and L2 for XEhI-28, VH3-33 and B3 for XEhI-B5, and VH4-4 and A19 for XEhI-H2, respectively. Flow cytometry analyses showed that the epitopes recognized by all of these MAbs were located on the surfaces of living trophozoites. Confocal microscopy demonstrated that most Igl1 and Igl2 proteins were colocalized on the surface and in the cytoplasm, but different localization patterns in intracellular vacuoles were also present. The preincubation of trophozoites with XEhI-20, XEhI-B5, and XEhI-H2 caused significant inhibition of the adherence of trophozoites to Chinese hamster ovary cells, whereas preincubation with XEhI-28 did not do so. XEhI-20, XEhI-B5, and XEhI-H2 were injected intraperitoneally into hamsters 24 h prior to intrahepatic challenge with E. histolytica trophozoites. One week later, the mean abscess size in groups injected with one of the three MAbs was significantly smaller than that in controls injected with polyclonal IgG or IgM isolated from healthy humans. These results demonstrate that human MAbs to Igls may be applicable for immunoprophylaxis of amebiasis.

scholarly journals Human Monoclonal Antibodies againstPseudomonas aeruginosa Lipopolysaccharide Derived from Transgenic Mice Containing Megabase Human Immunoglobulin Loci Are Opsonic and Protective against Fatal Pseudomonas Sepsis

2001 ◽  
Vol 69 (4) ◽  
pp. 2223-2229 ◽  
Author(s):  
Sonali Hemachandra ◽  
Kulwant Kamboj ◽  
Janna Copfer ◽  
Gerald Pier ◽  
Larry L. Green ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Transgenic Mice ◽  
Variable Region ◽  
Human Immunoglobulin ◽  
High Avidity ◽  
Genes Encoding ◽  
Antibody Titers ◽  
Multiple Donors ◽  
Human Polymorphonuclear Leukocytes ◽  
Variable Region Genes

ABSTRACT Pseudomonas aeruginosa is a significant human pathogen, and no vaccine is commercially available. Passive antibody prophylaxis using monoclonal antibodies (MAb) against protectiveP. aeruginosa epitopes is an alternative strategy for preventing P. aeruginosa infection, but mouse MAb are not suitable for use in humans. Polyclonal human antibodies from multiple donors have variable antibody titers, and human MAb are difficult to make. We used immunoglobulin-inactivated transgenic mice reconstituted with megabase-size human immunoglobulin loci to generate a human MAb against the polysaccharide (PS) portion of the lipopolysaccharide O side chain of a common pathogenic serogroup ofP. aeruginosa, 06ad. The anti-PS human immunoglobulin G2 MAb made from mice immunized with heat-killed P. aeruginosa was specific for serogroup 06ad pseudomonas. The MAb was highly opsonic for the uptake and killing of P. aeruginosa by human polymorphonuclear leukocytes in the presence of human complement. In addition, 25 μg of the MAb protected 100% of neutropenic mice from fatal P. aeruginosasepsis. DNA sequence analysis of the genes encoding the MAb revealed VH3 and Vκ2/A2 variable-region genes, similar to variable-region genes in humans immunized with bacterial PS and associated with high-avidity anti-PS antibodies. We conclude that human MAb to P. aeruginosa made in these transgenic mice are highly protective and that these mice mimic the antibody response seen in humans immunized with T-cell-independent antigens such as bacterial PS.

scholarly journals Use of Chinese hamster ovary cells with altered glycosylation patterns to define the carbohydrate specificity of Entamoeba histolytica adhesion.

1988 ◽  
Vol 167 (5) ◽  
pp. 1725-1730 ◽  
Author(s):  
E Li ◽  
A Becker ◽  
S L Stanley
Keyword(s):  
Entamoeba Histolytica ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Cellular Receptor ◽  
Carbohydrate Specificity ◽  
Complex Type ◽  
Ovary Cells ◽  
Altered Glycosylation ◽  
Inhibition Studies

We compared the adherence of E. histolytica trophozoites with a panel of lectin-resistant CHO mutants with altered glycosylation patterns. Our results coupled with data from saccharide inhibition studies indicate that terminal N-acetyllactosamine units on Asn-linked complex type oligosaccharides provide the major determinants on the cellular receptor for E. histolytica adhesion.

The diversity of antigen-specific monoclonal antibodies from transgenic mice bearing human immunoglobulin gene miniloci

1994 ◽  
Vol 24 (11) ◽  
pp. 2672-2681 ◽  
Author(s):  
Simon D. Wagner ◽  
Andrei V. Popov ◽  
Sarah L. Davies ◽  
Jian Xian ◽  
Michael S. Neuberger ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Transgenic Mice ◽  
Human Immunoglobulin ◽  
Immunoglobulin Gene

Predicting the expression of recombinant monoclonal antibodies in Chinese hamster ovary cells based on sequence features of the CDR3 domain

2013 ◽  
Vol 30 (1) ◽  
pp. 188-197 ◽  
Author(s):  
Leon P. Pybus ◽  
David C. James ◽  
Greg Dean ◽  
Tim Slidel ◽  
Colin Hardman ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Ovary Cells ◽  
Sequence Features

scholarly journals Functional cooperativity mediated by rationally selected combinations of human monoclonal antibodies targeting the henipavirus receptor binding protein

2021 ◽  
Author(s):  
Michael P. Doyle ◽  
Nurgun Kose ◽  
Viktoriya Borisevich ◽  
Elad Binshtein ◽  
Moushimi Amaya ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Receptor Binding ◽  
Binding Protein ◽  
Severe Disease ◽  
Hendra Virus ◽  
Human Monoclonal Antibodies ◽  
Human Mabs ◽  
Viral Attachment ◽  
Antigenic Sites ◽  
Receptor Binding Protein

AbstractHendra virus (HeV) and Nipah virus (NiV), the prototypic members of the Henipavirus (HNV) genus, are emerging, zoonotic paramyxoviruses known to cause severe disease across six mammalian orders, including humans (Eaton et al., 2006). While several research groups have made strides in developing candidate vaccines and therapeutics against henipaviruses, such countermeasures have not been licensed for human use, and significant gaps in knowledge about the human immune response to these viruses exist. To address these gaps, we isolated a large panel of human monoclonal antibodies (mAbs) from the B cells of an individual with prior occupation-related exposure to the equine HeV vaccine (Equivac® HeV). Competition-binding and hydrogen-deuterium exchange mass spectrometry (HDX-MS) studies identified at least six distinct antigenic sites on the HeV/NiV receptor binding protein (RBP) that are recognized by human mAbs. Antibodies recognizing multiple antigenic sites potently neutralized NiV and/or HeV isolates in vitro. The most potent class of cross-reactive antibodies achieved neutralization by blocking viral attachment to the host cell receptors ephrin-B2 and ephrin-B3. Antibodies from this class mimic receptor binding by inducing a receptor-bound conformation to the HeV-RBP protein tetramer, exposing an epitope that appears to lie hidden in the interface between protomers within the HeV-RBP tetramer. Antibodies that recognize this cryptic epitope potently neutralized HeV and NiV. Flow cytometric studies using cell-surface-displayed HeV-RBP protein showed that cross-reactive, neutralizing mAbs from each of these classes cooperate for binding. In a highly stringent hamster model of NiVB infection, antibodies from both classes reduced morbidity and mortality and achieved synergistic protection in combination and provided therapeutic benefit when combined into two bispecific platforms. These studies identified multiple candidate mAbs that might be suitable for use in a cocktail therapeutic approach to achieve synergistic antiviral potency and reduce the risk of virus escape during treatment.

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