Prediction of the interacting surfaces in a trimolecular complex formed between the major dust mite allergen Der p 1, a mouse monoclonal anti-Der p 1 antibody, and its anti-idiotype (original) (raw)
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Three-dimensional structure and antigen binding specificity of antibodies
Biochimie, 1990
A number of specific Fab and Fv fragments and their complexes with antigens (avian lysozymes), haptens, and anti-idiotopic Fabs have been studied by immunochemical and crystallographic techniques. Antigen and antibody interact through closely complementary contacting surfaces, without major conformational changes. An idiotopic determinant of a monoclonal antibody is shown to include parts of most of its complementarity determining regions. The specificity of antigen recognition resides in the close complementarity of the antigenic determinant with the antibody combining site.
Journal of Molecular Recognition, 1994
The reaction between the mouse (BALB/c) anti-idiotopic monoclonal antibodies E225 and E5.2 and idiotopes on the (BALB/c) anti-lysozyme monoclonal antibody D1.3 has been characterized by titration calorimetry, by equilibrium sedimentation and by the determination of binding association and dissociation rates. The reaction between E5.2 and D1.3 is driven by a large negative enthalpy and its rate and equilibrium association constants are comparable to those observed in other antigen-antibody reactions. In contrast, the reaction between E225 and D1.3 is entropically driven and characterized by slow association kinetics (1 X 10' M -I sec-I) and a resulting low equilibrium constant (K. = 2 X lo5 M-I). A correlation of these properties with the three-dimensional structure of the Fab225-FabD1.3 complex, previously determined by X-ray diffraction methods to 2.5 A resolution, indicates that conformational changes of several D1.3 contacting residues, located in its complementarity determining regions, may explain these features of the reaction.
Molecular Pathology, 2000
Background—A mouse monoclonal antibody (2C7/IgG2bκ) has been described recently, which is directed against the major house dust mite allergen Der p 1, and whose epitope specificity is representative of a major component of the human IgE anti-Der p 1 response. Aims—To characterise an anti-idiotypic antibody (2G10/IgG1κ) raised against monoclonal antibody 2C7 as surrogate human IgE anti-Der p 1. Methods—The specificity of the anti-idiotype antibody 2G10 was determined by competitive inhibition experiments using ...
Non-classical binding of a polyreactive α-type anti-idiotypic antibody to B cells
Molecular Immunology
Detailed information on the immunological relevance of ␣-type anti-idiotypic antibodies is lacking after more than 30 years since Jerne postulated his Idiotypic Network Theory. The B7Y33 mutant is a mousehuman chimeric version of the B7 MAb, a polyreactive ␣-type anti-idiotypic antibody, generated against an anti-GM2 ganglioside IgM Ab1 antibody. It retained the unusual self-binding activity and multispecificity of the parental murine antibody, being able to recognize several anti-ganglioside IgM antibodies as well as non-immunoglobulin antigens. Previous work with the murine B7 MAb suggested that this antibody might have immunoregulatory properties, and therefore we investigated the possible interaction of B7Y33 with immune cells. We found that B7Y33 binds to human and murine B lymphocytes. Inhibition assays using flow cytometry indicated that this antibody is capable of binding the Fc ␥ receptor II (Fc␥RII). The recognition of Fc␥RII-expressing K562, Raji and Daudi human cell lines, together with the capability of inhibiting the binding of an anti-human Fc␥RII antibody to these cells, suggest that B7Y33 interacts with both the Fc␥RIIa and Fc␥RIIb isoforms. We evaluated the contribution to the binding of different surface-exposed residues at the top of the heavy chain variable region (VH) CDR loops through the construction of mutants with substitutions in the three conventional VH CDRs (HCDRs) and the "HCDR4", located in the framework 3 (HFR3). In addition, we assessed the involvement of the Fc region by performing key mutations in the CH2 domain. Furthermore, chimeric hybrid molecules were obtained by combining the B7Y33 heavy chain with unrelated light chains. Our results indicate that the multispecificity and self-binding properties of B7Y33 are not linked to its recognition of B lineage cells, and that this phenomenon occurs in a non-classical way with the participation of both the variable and constant regions of the antibody. Two possible models for this interaction are proposed, with B7Y33 binding to two Fc␥RIIb molecules through the Fc and Fv regions, or simultaneously to Fc␥RIIb and another unknown antigen on B cells. The Fc␥RIIb has recently received great attention as an attractive target for therapies directed to B lymphocytes. The recognition of peripheral B lymphocytes from B cell chronic lymphocytic leukemia (B-CLL) patients by B7Y33 suggests its potential application for the treatment of B cell malignancies.
Journal of immunology (Baltimore, Md. : 1950), 2015
Der p 1 is a major allergen from the house dust mite, Dermatophagoides pteronyssinus, that belongs to the papain-like cysteine protease family. To investigate the antigenic determinants of Der p 1, we determined two crystal structures of Der p 1 in complex with the Fab fragments of mAbs 5H8 or 10B9. Epitopes for these two Der p 1-specific Abs are located in different, nonoverlapping parts of the Der p 1 molecule. Nevertheless, surface area and identity of the amino acid residues involved in hydrogen bonds between allergen and Ab are similar. The epitope for mAb 10B9 only showed a partial overlap with the previously reported epitope for mAb 4C1, a cross-reactive mAb that binds Der p 1 and its homolog Der f 1 from Dermatophagoides farinae. Upon binding to Der p 1, the Fab fragment of mAb 10B9 was found to form a very rare α helix in its third CDR of the H chain. To provide an overview of the surface properties of the interfaces formed by the complexes of Der p 1-10B9 and Der p 1-5H8, ...
Clinical <html_ent glyph="@amp;" ascii="&"/> Experimental Allergy, 1998
Background Der p 1, a major mite allergen, elicits IgE antibody responses in 80% of patients suffering from dust mite allergy. Given the potent IgE eliciting properties of Der p 1, there is considerable interest in studying the molecular architecture of the variable (Fv) region of IgE antibodies specific for this allergen. Objectives IgE is present in human serum at extremely low concentrations, and as such it is practically impossible to purify sufficient quantities for structural studies. We have therefore sought to sequence and model a representative murine monoclonal (MoAb) anti-Der p 1 antibody, as a surrogate human IgE. Methods The cDNA coding for the Fv region of an anti-Der p 1 MoAb (2C7), that mimics the binding of human IgE to Der p 1, was amplified by PCR, cloned and sequenced. The predicted amino acid sequences were then compared with a directory of human germline Vgene segments. Modelling of the Fv region of MoAb 2C7 was carried out using the extensive database of existing immunoglobulin structures in the Brookhaven PDB. Results The MoAb 2C7 heavy chain showed greater than 70% homology with three members of the V H 3 family, DP-35, DP-53 and DP-54. Similarly, the light chain showed greater than 70% homology with 11 V K sequences, including the V K II sequences DPK18, DPK19 and DPK28. A molecular model of the Fv region of MoAb 2C7 was generated and can be accessed from the EMBL databank. Conclusions Antibodies similar to MoAb 2C7 could be generated as part of the human repertoire. The availability of 3-dimensional model of MoAb 2C7, as a surrogate human IgE antibody, combined with further data on its epitope specificity, will facilitate studies into IgE antibody responses to Der p 1. Fig. 5. A molecular model of the Fv region of MoAb 2C7, showing a side view (left) and a top view (right). The heavy chain and the light chain are shown in blue and green, respectively, and the CDRs of the heavy chain and the light chain are shown in orange and red, respectively.
A central core structure in an antibody variable domain determines antigen specificity
Protein Engineering Design and Selection, 2001
Antibody binding sites provide an adaptable surface capable of interacting with essentially any molecular target. Using CDR shuffling, residues important for the assembly of mucin-1 specific paratopes were defined by random recombination of the complementarity determining regions derived from a set of mucin-1 specific clones, previously selected from an antibody fragment library. It was found that positions 33 and 50 in the heavy chain and 32, 34, 90, 91 and 96 in the light chain were conserved in many of the clones. These particular residues seem to be located centrally in the binding site as indicated by a structure model analysis. The importance of several of these conserved residues was supported by their presence in a mouse monoclonal antibody with a known structure and the same epitope specificity. Several of these corresponding residues in the mouse monoclonal antibody are known to interact with the antigen. In conclusion, critical residues important for maintaining a human antigen-specific binding site during the process of in vitro antibody evolution were defined. Furthermore, an explanation for the observed restricted germline gene usage in certain antibody responses against protein epitopes is provided.