Human Antibody Induction to the Idiotypic and Anti-Idiotypic Determinants of a Monoclonal Antibody Against a Gastrointestinal Carcinoma Antigen

1985 ◽  
pp. 75-89 ◽  
Author(s):  
E. DeFreitas ◽  
H. Suzuki ◽  
D. Herlyn ◽  
M. Lubeck ◽  
H. Sears ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Human Antibody ◽  
Gastrointestinal Carcinoma ◽  
Antibody Induction

scholarly journals Generation and Activity Evaluation of a Mouse-Human Immunoglobulin G1 Chimeric Antibody to Histoplasma capsulatum HSP60

2021 ◽  
Author(s):  
Ágata Nogueira D'Áurea Moura ◽  
Scott J. Garforth ◽  
Leandro Buffoni Roque da Silva ◽  
Darien Woodley ◽  
Filipe Vieira Barbalho ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Histoplasma Capsulatum ◽  
Physiological Stress ◽  
Human Monoclonal Antibody ◽  
Current Treatment ◽  
Chimeric Antibody ◽  
Human Antibody ◽  
Chimeric Mouse ◽  
Dimorphic Fungi

Heat shock proteins (Hsps) are highly conserved molecules that are constitutively expressed and upregulated in response to physiological stress conditions. These immunogenic chaperones can have essential functions in fungi, particularly in dimorphic pathogens. Histoplasma capsulatum and Paracoccidioides species are dimorphic fungi that are the causative agents of histoplasmosis and paracoccidioidomycosis, respectively, which are systemic mycoses with significant rates of morbidity and mortality. Current treatment consists of long-term antifungal agents, and there is an urgent need for new therapeutic approaches with higher efficacy, lower toxicity, better biodistribution and improved selectivity. We engineered an immunoglobulin G1 (IgG1) isotype chimeric mouse-human monoclonal antibody, titled ch-MAb 4E12, from the parental IgG2a MAb 4E12, a monoclonal antibody to H. capsulatum Hsp60 that is protective in experimental histoplasmosis and paracoccidioidomycosis models elicited by H. capsulatum var. capsulatum and Paracoccidioides lutzii, respectively. The ch-MAb 4E12 increased phagolysosomal fusion and enhanced the yeasts uptake by PMA differentiated human THP1 macrophage cells in vitro. At low concentrations, the chimeric antibody significantly reduced the pulmonary and splenic fungal burden compared to an irrelevant antibody or no treatment. These results are the first to show that a chimeric mouse-human antibody can modify infection caused by dimorphic fungi.

scholarly journals Structure-Based Modification of an Anti-neuraminidase Human Antibody Restores Protection Efficacy against the Drifted Influenza Virus

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
Haihai Jiang ◽  
Weiyu Peng ◽  
Jianxun Qi ◽  
Yan Chai ◽  
Hao Song ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Influenza Virus ◽  
Antibody Fragment ◽  
Salt Bridge ◽  
Cross Reactivity ◽  
Human Antibody ◽  
Influenza Strain ◽  
Group 2 ◽  
Fragment Antigen Binding ◽  
Group 1

ABSTRACT Here, we investigate a monoclonal antibody, Z2B3, isolated from an H7N9-infected patient, that exhibited cross-reactivity to both N9 (group 2) and a broad range of seasonal and avian N1 (group 1) proteins but lost activity to the N1 with the substitution K432E. This substitution exists in 99.25% of seasonal influenza strains after 2013. The NA-Z2B3 complex structures indicated that Z2B3 binds within the conserved active site of the neuraminidase (NA) protein. A salt bridge between D102 in Z2B3 and K432 in NA plays an important role in binding. Structure-based modification of Z2B3 with D102R in heavy chain reversed the salt bridge and restored the binding and inhibition of N1 with E432. Furthermore, Z2B3-D102R can protect mice from A/Serbia/NS-601/2014 H1N1 virus (NA contains E432) infection while the wild-type Z2B3 antibody shows no protection. This study demonstrates that a broadly reactive and protective antibody to NA can be in principle edited to restore binding and inhibition to recently drifted N1 NA and regain protection against the variant influenza strain. IMPORTANCE The immune system produces antibodies to protect the human body from harmful invaders. The monoclonal antibody (MAb) is one kind of effective antivirals. In this study, we isolated an antibody (Z2B3) from an H7N9 influenza virus-infected child. It shows cross-reactivity to both group 1 (N1) and group 2 (N9) neuraminidases (NAs) but is sensitive to N1 NA with a K432E substitution. Structural analysis of the NA-antibody fragment antigen-binding (Fab) complex provides a clue for antibody modification, and the modified antibody restored binding and inhibition to recently drifted N1 NA and regained protection against the variant influenza strain. This finding suggests that antibodies to NA may be a useful therapy and can be in principle edited to defeat drifted influenza virus.

scholarly journals Cross-Reactive Human Immunodeficiency Virus Type 1-Neutralizing Human Monoclonal Antibody That Recognizes a Novel Conformational Epitope on gp41 and Lacks Reactivity against Self-Antigens

2008 ◽  
Vol 82 (14) ◽  
pp. 6869-6879 ◽  
Author(s):  
Mei-Yun Zhang ◽  
Bang K. Vu ◽  
Anil Choudhary ◽  
Hong Lu ◽  
Michael Humbert ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Human Immunodeficiency Virus ◽  
Conformational Epitope ◽  
Heptad Repeat ◽  
Enzyme Linked Immunosorbent Assay ◽  
Human Antibody ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Self Antigens

ABSTRACT Broadly cross-reactive human immunodeficiency virus (HIV)-neutralizing antibodies are infrequently elicited in infected humans. The two best-characterized gp41-specific cross-reactive neutralizing human monoclonal antibodies, 4E10 and 2F5, target linear epitopes in the membrane-proximal external region (MPER) and bind to cardiolipin and several other autoantigens. It has been hypothesized that, because of such reactivity to self-antigens, elicitation of 2F5 and 4E10 and similar antibodies by vaccine immunogens based on the MPER could be affected by tolerance mechanisms. Here, we report the identification and characterization of a novel anti-gp41 monoclonal antibody, designated m44, which neutralized most of the 22 HIV type 1 (HIV-1) primary isolates from different clades tested in assays based on infection of peripheral blood mononuclear cells by replication-competent virus but did not bind to cardiolipin and phosphatidylserine in an enzyme-linked immunosorbent assay and a Biacore assay nor to any protein or DNA autoantigens tested in Luminex assays. m44 bound to membrane-associated HIV-1 envelope glycoproteins (Envs), to recombinant Envs lacking the transmembrane domain and cytoplasmic tail (gp140s), and to gp41 structures containing five-helix bundles and six-helix bundles, but not to N-heptad repeat trimers, suggesting that the C-heptad repeat is involved in m44 binding. In contrast to 2F5, 4E10, and Z13, m44 did not bind to any significant degree to denatured gp140 and linear peptides derived from gp41, suggesting a conformational nature of the epitope. This is the first report of a gp41-specific cross-reactive HIV-1-neutralizing human antibody that does not have detectable reactivity to autoantigens. Its novel conserved conformational epitope on gp41 could be helpful in the design of vaccine immunogens and as a target for therapeutics.

Intranuclear distribution of Epstein-Barr virus-encoded nuclear antigens EBNA-1, -2, -3 and -5

1991 ◽  
Vol 99 (3) ◽  
pp. 497-502 ◽  
Author(s):  
W.Q. Jiang ◽  
V. Wendel-Hansen ◽  
A. Lundkvist ◽  
N. Ringertz ◽  
G. Klein ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Epstein Barr Virus ◽  
Digital Image Analysis ◽  
Mouse Monoclonal Antibody ◽  
Human Antibody ◽  
Barr Virus ◽  
Nuclear Antigens ◽  
Topographical Analysis ◽  
Epstein Barr ◽  
Nuclear Structures

Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCLs) express at least seven virally encoded proteins. Their functional role, and their relationships to each other and to normal nuclear constituents are virtually unknown. As the first step towards a topographical study, the intranuclear distribution of EBV-encoded nuclear antigens EBNA-1, -2, -3 and -5 (abbreviated E1, E2 etc.) was examined in EBV-transformed LCLs by immunofluorescence and digital image analysis of fluorescence patterns. E1-E3 showed a finely granular distribution. The E2 patterns were virtually identical when comparing indirect staining using an E2-specific mouse monoclonal antibody with anticomplement immunofluorescence using a human antibody, rendered monospecific to E2 by absorption. The E1/E2 patterns showed 32% overlap and the E2/E3 10% overlap in the high overlap category (66.7-100%), while the E2/E2 comparison with two reagents showed 61% overlap in this category. This suggests that E2 and E3 largely appear in different nuclear structures, whereas E1 appears to be randomly distributed with regard to E2. The E5 pattern was radically different from that of E1, E2 and E3. The anti-E5 mouse monoclonal antibody detected 4–10 huge, globular, sharply circumscribed dots, located in dispersed chromatin areas, while the distribution of E1, E2 and E3 showed no obvious relationship to chromatin distribution. The methods described here allow a more refined topographical analysis of the EBNA protein family, mostly in relation to each other, in relation to other nuclear proteins, and with respect to specialized functional domains in interphase chromatin.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of a New Fully Human Anti-CD20 Monoclonal Antibody for the Treatment of B-Cell Malignancies.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2349-2349
Author(s):  
Gadi Gazit Bornstein ◽  
Christophe Queva ◽  
Mohammad Tabrizi ◽  
Anne VanAbbema ◽  
Carlos Chavez ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
B Cell ◽  
Clinical Activity ◽  
Human Antibody ◽  
B Cell Malignancies ◽  
B Lymphoma ◽  
Hodgkin's Lymphomas ◽  
Anti Tumor Activity

Abstract In spite of the widespread use of Rituximab, a chimeric monoclonal antibody with demonstrated efficacy in the treatment of non-Hodgkin’s lymphomas, there is a recognized need to develop fully human antibodies with improved efficacy. Towards this end, using XenoMouse™ technology, a fully human IgG1 monoclonal antibody specific to human CD20 was generated. This antibody, denoted mAb 1.5.3, evoked enhanced pro-apoptotic activity in vitro, as compared to Rituximab, in the Ramos human lymphoma cell line. In addition, mAb 1.5.3 was active in mediating complement dependent cytotoxicity (CDC) and elicited improved antibody-dependent cellular cytotoxicity (ADCC) relative to Rituximab in Ramos, Raji, and Daudi human B-lymphoma lines. To recapitulate various aspects of acquired resistance to Rituximab, as observed in a subpopulation of patients, Rituximab-resistant clones were established from lymphoma lines. Interestingly, mAb 1.5.3 demonstrated superior cytolytic activity against engineered Rituximab-refractory lymphoma clones, as well as across multiple human B-lymphoma and chronic B-cell leukemia lines in an in vitro whole blood assay. Furthermore, mAb 1.5.3 exhibited enhanced anti-tumor activity in Rituximab-sensitive cell lines and -refractory engineered lymphoma clones in vivo. Lastly, mAb 1.5.3 produced a superior B-cell depletion profile in lymph node organs and bone marrow as compared to Rituximab in a primate PD model. In contrast to Rituximab, mAb 1.5.3 is a fully human antibody and is thus anticipated to exhibit a longer serum half-life with minimal immunogenicity following repeated administration. In sum, these results demonstrate the superior anti-tumor activity of mAb 1.5.3 relative to Rituximab and its potential for improved clinical activity in the treatment of B-cell malignancies.

The principle of the MAIEA technique depends on the binding of two antibodies made in different species to different determinants on the same membrane component to form of a tri-molecular complex [4]. Briefly, a murine monoclonal antibody (MAb) and human antibody are incubated simultaneously with red cells. Excess antibody is removed, the sensitized cells are solubilised with Triton, so the tri-molecular complex is released into solution. The complex is detected by an ELISA type assay. The tri-molecular complex is captured by an anti-mouse globulin precoated onto a microtitre plate. The human antibody is then detected by a peroxidase-conjugated anti-human IgG. A positive reaction gives a high absorbance value and a negative reaction gives a low absorbance value. A negative result is obtained when the antibodies used bind to different membrane components, so no tri-molecular complex is formed. A negative result is also obtained when the monoclonal antibody and human antibody compete for the same epitope. Results can be represented as ratios of absorbances for antigen positive to antigen negative cells or as bar charts. In these studies a murine anti-CR1 (E11) and human anti-Kna and other Knops system antibodies were used against antigen positive and antigen negative cells. Absorbances for antigen positive cells with anti-Kna, anti-McCa anti-Sla and anti-Yka were high and results for the antigen-negative cells were low [8]. Comparison of chymotrypsin treated Kn(a+) cells with Kn(a-) cells showed that chymotrypsin did indeed destroy Kna antigen; chymotrypsin treated cells, therefore, were suitable cells to use as antigen negative cells when cells of rare phenotype were not available [8]. These reactions gave significantly positive ratios (Table I). In contrast, low absorbances were recorded for Cs(a+) and Cs(a-) cells with anti-Csa, the 1:1 ratio indicating a negative result (Table I). Serologically the Helgeson phenotype cells have a Knops null phenotype, all 4 antigens are negative but the antigens could be detected by flow cytometry and in immune precipitation [6,7]. Moulds and colleagues provided an explanation for this when they found that such cells did not completely lack CR1 but had a low copy number of CR1 molecules per cell [9]. Had it not been known already, the presence of Knops system antigens on Helgeson phenotype cells could have been deduced from the MAIEA results. The absorbance values for Helgeson phenotype cells were significantly higher than for antigen negative cells for Kna, McCa and Yka [8]. MAIEA has confirmed that Kna, McCa, Sla and Yka but not Csa are associated with the CR1 molecule in the red cell membrane and can detect weak expression of CR1 antigens on Helgeson phenotype cells [8]. MAIEA is useful for investigating problem antibodies suspected to be Knops system antibodies and can also be used to Knops phenotype cells with poor expression of Knops system antigens.

1995 ◽  
pp. 189-189
Keyword(s):  
Monoclonal Antibody ◽  
Molecular Complex ◽  
Human Antibody ◽  
Red Cell Membrane ◽  
A Cells ◽  
Low Copy Number ◽  
Rare Phenotype ◽  
Immune Precipitation ◽  
Weak Expression ◽  
Membrane Components

The blocking of human antibody-dependent, eosinophil-mediated killing ofSchistosoma mansonischistosomula by monoclonal antibodies which cross-react with a polysaccharide-containing egg antigen

Parasitology ◽  
1987 ◽  
Vol 94 (2) ◽  
pp. 269-280 ◽  
Author(s):  
D. W. Dunne ◽  
Q. D. Bickle ◽  
A. E. Butter Worth ◽  
B. A. Richardson
Keyword(s):  
Monoclonal Antibody ◽  
Monoclonal Antibodies ◽  
Fluorescent Antibody ◽  
Human Infection ◽  
Human Antibody ◽  
Indirect Fluorescent Antibody ◽  
Antibody Assay ◽  
Antigen Preparation ◽  
Human Infections ◽  
Egg Antigen

SUMMARYThree IgM monoclonal antibodies, M22G11P, M7B7 and M22B3G, which reacted with the surfaceof Schistosoma mansonischistosomula in an indirect fluorescent antibody assay, were found to recognize a polysaccharide-containing egg antigen previously designated K3. The monoclonal antibodies and a monospecific rabbit anti-K3serum also recognized a crossreacting antigen in a crude cercarial antigen preparation. In an eosinophil-mediated schistosomulum killing assay, all three monoclonal antibodies significantly inhibited the level of killing produced by human infection serum. An IgG3 monoclonal antibody, M22C1C, which also recognized the egg antigen K3, did not inhibit eosinophil-mediated killing. However, when lower concentrations of human serum were used in the assay, this monoclonal antibody significantly enhanced the level of killing, despite having no capacity to induce eosinophil-mediated damage in the absence of human infection serum. On the basis of these and other results we suggest the possibility that antibodies toS. mansoniegg antigens which cross-react with the surface of the early post-penetration schistosomulum may influence the effective expression of antibody-dependent, eosinophil-mediated effector mechanisms in human infections.

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