François Ehrenmann

IMGT/3Dstructure-DB and IMGT/DomainGapAlign: a database and a tool for immunoglobulins or antibodies, T cell receptors, MHC, IgSF and MhcSF

IMGT/3Dstructure-DB is the three-dimensional (3D) structure database of IMGT®, the international ImMunoGenetics information system® that is acknowledged as the global reference in immunogenetics and immunoinformatics. IMGT/3Dstructure-DB contains 3D structures of immunoglobulins (IG) or antibodies, T cell receptors (TR), major histocompatibility complex (MHC) proteins, antigen receptor/antigen complexes (IG/Ag, TR/peptide/MHC) of vertebrates; 3D structures of related proteins of the immune system (RPI) of vertebrates and invertebrates, belonging to the immunoglobulin and MHC superfamilies (IgSF and MhcSF, respectively) and found in complexes with IG, TR or MHC. IMGT/3Dstructure-DB data are annotated according to the IMGT criteria, using IMGT/DomainGapAlign, and based on the IMGT-ONTOLOGY concepts and axioms. IMGT/3Dstructure-DB provides IMGT gene and allele identification (CLASSIFICATION), region and domain delimitations (DESCRIPTION), amino acid positions according to the IMGT unique numbering (NUMEROTATION) that are used in IMGT/3Dstructure-DB cards, results of contact analysis and renumbered flat files. In its Web version, the IMGT/DomainGapAlign tool analyses amino acid sequences, per domain. Coupled to the IMGT/Collier-de-Perles tool, it provides an invaluable help for antibody engineering and humanization design based on complementarity determining region (CDR) grafting as it precisely defines the standardized framework regions (FR-IMGT) and CDR-IMGT. IMGT/3Dstructure-DB and IMGT/DomainGapAlign are freely available at http://www.imgt.org.

IG,TR and IgSF, MHC and MhcSF: what do we learn from the IMGT Colliers de Perles?

The immunoglobulin superfamily (IgSF) comprises the immunoglobulins (IG), T cell receptors (TR) and proteins that have the common feature of having at least one Ig-like domain. The major histocompatibility complex (MHC) superfamily (MhcSF) comprises, in addition to the MHC, proteins which share the common feature of having Mhc-like domains. IMGT, the international ImMunoGeneTics information system (http://imgt.cines.fr) has set up a unique numbering system and standardized 2D graphical representations, or IMGT Colliers de Perles, which take into account the structural features of the Ig-like and Mhc-like domains. In this article, we review the IMGT Scientific chart rules for the description of the IgSF (V and C types) and of the MhcSF (G type) domains. These rules are based on the IMGT-ONTOLOGY axioms and concepts and are applicable for the sequence and structure analysis, whatever the species, the IgSF or MhcSF protein, or the chain type. These IMGT Colliers de Perles are particularly useful for antibody engineering, sequence-structure analysis, visualization and comparison of positions for mutations, polymorphisms and contact analysis.

IMGT/Collier de Perles: IMGT Standardized Representation of Domains (IG, TR, and IgSF Variable and Constant Domains, MH and MhSF Groove Domains)

Cold Spring Harb Protoc; François Ehrenmann, Véronique Giudicelli, Patrice Duroux and Marie-Paule Lefranc and IgSF Variable and Constant Domains, MH and MhSF Groove Domains) IMGT/Collier de Perles: IMGT Standardized Representation of Domains (IG, TR, Service Email Alerting click here. Receive free email alerts when new articles cite this article Categories Subject Cold Spring Harbor Protocols. Browse articles on similar topics from (28 articles) Sequence Database Searching (15 articles) Phylogenetic Prediction (89 articles) Immunology, general (322 articles) Genetics, general (74 articles) Computational Biology (167 articles) Characterization of Proteins (131 articles) Bioinformatics/Genomics, general (33 articles) Alignment of Sequences

Use of IMGT(®) databases and tools for antibody engineering and humanization.

IMGT(®), the international ImMunoGeneTics information system(®) (http://www.imgt.org), was created in 1989 to manage the huge diversity of the antigen receptors, immunoglobulins (IG) or antibodies, and T cell receptors (TR). Standardized sequence and structure analysis of antibody using IMGT(®) databases and tools allows one to bridge, for the first time, the gap between antibody sequences and three-dimensional (3D) structures. This is achieved through the IMGT Scientific chart rules, based on the IMGT-ONTOLOGY concepts of classification (IMGT gene and allele nomenclature), description (IMGT standardized labels), and numerotation (IMGT unique numbering and IMGT Colliers de Perles). IMGT(®) is the international reference for immunogenetics and immunoinformatics and its standards are particularly useful for antibody humanization and evaluation of immunogenicity. IMGT(®) databases for antibody nucleotide sequences and genes include IMGT/LIGM-DB and IMGT/GENE-DB, respectively, whereas nucleotide sequence analysis is performed by the IMGT/V-QUEST, IMGT/HighV-QUEST, and IMGT/JunctionAnalysis tools. In this chapter, we focus on IMGT(®) databases and tools for amino acid sequences, two-dimensional (2D) and three-dimensional (3D) structures: the IMGT/DomainGapAlign and IMGT/Collier-de-Perles tools, the IMGT/2Dstructure-DB database for amino acid sequences of monoclonal antibodies (mAb, suffix -mab) and fusion proteins for immune applications (FPIA, suffix -cept) of the World Health Organization/International Nonproprietary Name (WHO/INN) programme and other proteins of interest, and the IMGT/3Dstructure-DB database for crystallized antibodies and its associated tools (IMGT/StructuralQuery, IMGT/DomainSuperimpose).

Mass spectrometry detection of G3m and IGHG3 alleles and follow-up of differential mother and neonate IgG3

Mass spectrometry (MS) analysis for detection of immunoglobulins (IG) of the human IgG3 subclass is described that relies on polymorphic amino acids of the heavy gamma3 chains. IgG3 is the most polymorphic human IgG subclass with thirteen G3m allotypes located on the constant CH2 and CH3 domains of the gamma3 chain, the combination of which leads to six major G3m alleles. Amino acid changes resulting of extensive sequencing previously led to the definition of 19 IGHG3 alleles that have been correlated to the G3m alleles. As a proof of concept, MS proteotypic peptides were defined which encompass discriminatory amino acids for the identification of the G3m and IGHG3 alleles. Plasma samples originating from ten individuals either homozygous or heterozygous for different G3m alleles, and including one mother and her baby (drawn sequentially from birth to 9 months of age), were analyzed. Total IgG3 were purified using affinity chromatography and then digested by a combination of AspN and trypsin proteases, and peptides of interest were detected by mass spectrometry. The sensitivity of the method was assessed by mixing variable amounts of two plasma samples bearing distinct G3m allotypes. A label-free approach using the high-performance liquid chromatography (HPLC) retention time of peptides and their MS mass analyzer peak intensity gave semi-quantitative information. Quantification was realized by selected reaction monitoring (SRM) using synthetic peptides as internal standards. The possibility offered by this new methodology to detect and quantify neo-synthesized IgG in newborns will improve knowledge on the first acquisition of antibodies in infants and constitutes a promising diagnostic tool for vertically-transmitted diseases.

Standardized Sequence and Structure Analysis of Antibody Using IMGT

IMGT, the international ImMunoGeneTics information system (http://www. imgt.org) (Lefranc et al. 2009), was created in 1989 at Montpellier, France (CNRS and Universite Montpellier 2), to standardize the immunogenetics data and to manage the huge diversity of the antigen receptors, immunoglobulins (IG) or antibodies and T cell receptors (TR) (Lefranc and Lefranc 2001a, b). IMGT is the international reference in immunogenetics and immunoinformatics, and its standards have been approved by the World Health Organization–International Union of Immunological Societies (WHO–IUIS) Nomenclature Committee (Lefranc 2007, 2008). It provides a common access to standardized and integrated data from genome, proteome, genetics and three-dimensional (3D) structures (Lefranc et al. 2005a). IMGT comprises six databases (for sequences, genes and 3D structures), 15 online tools and Web resources (more than 10,000 HTML pages) (Lefranc et al. 2009) (Fig. 2.1). The accuracy and the consistency of the IMGT data are based on IMGT-ONTOLOGY, the first ontology for immunogenetics and immunoinformatics (Giudicelli and Lefranc 1999; Lefranc et al. 2004; Duroux et al. 2008). IMGT provides the informatics frame and knowledge environment for a standardized analysis of the antibody sequences and 3D structures, in the context of antibody engineering (single chain Fragment variable (scFv), phage displays, combinatorial libraries) and antibody humanization (chimeric, humanized and human antibodies).

IMGT/DomainGapAlign: The IMGT® Tool for the Analysis of IG, TR, MH, IgSF, and MhSF Domain Amino Acid Polymorphism

IMGT/DomainGapAlign is the online tool of IMGT(®), the international ImMunoGeneTics information system(®), for the analysis of amino acid sequences and two-dimensional (2D) structures of domains. IMGT/DomainGapAlign allows the analysis of the closest variable (V) and constant (C) domains of immunoglobulins (IG) or antibodies, T cell receptors (TR), and immunoglobulin superfamily (IgSF) proteins, and of the groove (G) domains of major histocompatibility (MH; in humans, HLA for human leukocyte antigen) and MH superfamily proteins. IMGT/DomainGapAlign aligns the user own sequences against the IMGT domain reference directory, displays amino acid changes, creates IMGT gaps, and delimits the domain strands and loops (and helix for G domain) according to the IMGT unique numbering. IMGT/DomainGapAlign is coupled to the IMGT/Collier-de-Perles tool that draws standardized IMGT Colliers de Perles. The analysis is based on the IMGT-ONTOLOGY concepts of identification, classification, description, and numerotation generated from the axioms of the Formal IMGT-ONTOLOGY or IMGT-Kaleidoscope. IMGT/DomainGapAlign provides an invaluable help for antibody engineering and antibody humanization as it precisely defines the standardized framework regions (FR-IMGT) and complementarity determining regions (CDR-IMGT) to be grafted. IMGT/DomainGapAlign is freely available at http://www.imgt.org.