IMGT, the international ImMunoGeneTics information system: a standardized approach for immunogenetics and immunoinformatics

Abstract

IMGT, the international ImMunoGeneTics information system http://imgt.cines.fr, was created in 1989 by the Laboratoire d'ImmunoGénétique Moléculaire (LIGM) (Université Montpellier II and CNRS) at Montpellier, France. IMGT is a high quality integrated knowledge resource specialized in immunoglobulins (IG), T cell receptors (TR), major histocompatibility complex (MHC) of human and other vertebrates, and related proteins of the immune system (RPI) of any species which belong to the immunoglobulin superfamily (IgSF) and to the MHC superfamily (MhcSF). IMGT consists of five databases, ten on-line tools and more than 8,000 HTML pages of Web resources. IMGT provides a common access to standardized data from genome, genetics, proteome and three-dimensional structures. The accuracy and the consistency of IMGT data are based on IMGT-ONTOLOGY, a semantic specification of terms to be used in immunogenetics and immunoinformatics. IMGT-ONTOLOGY comprises six main concepts: IDENTIFICATION, CLASSIFICATION, DESCRIPTION, NUMEROTATION, ORIENTATION and OBTENTION. Based on these concepts, the controlled vocabulary and the annotation rules necessary for the immunogenetics data identification, classification, description and numbering and for the management of IMGT knowledge are defined in the IMGT Scientific chart. IMGT is the international reference in immunogenetics and immunoinformatics for medical research (repertoire analysis of the IG antibody sites and of the TR recognition sites in autoimmune and infectious diseases, AIDS, leukemias, lymphomas, myelomas), veterinary research (IG and TR repertoires in farm and wild life species), genome diversity and genome evolution studies of the adaptive immune responses, biotechnology related to antibody engineering (single chain Fragment variable (scFv), phage displays, combinatorial libraries, chimeric, humanized and human antibodies), diagnostics (detection and follow up of residual diseases) and therapeutical approaches (grafts, immunotherapy, vaccinology). IMGT is freely available at http://imgt.cines.fr.

Figure 1

IMGT, the international ImMunoGeneTics information system^® . Databases and tools for sequences, genes and structures are in green, yellow and blue, respectively. The IMGT Repertoire and other Web resources are not shown. Interactions in the genetics, genomics and structural approaches are represented with dotted, continuous and broken lines, respectively.

Figure 2

IMGT Colliers de Perles of a V-DOMAIN (A) and of a C-DOMAIN (B) (code PDB 1mcd in IMGT/3Dstructure-DB [9]). IMGT Colliers de Perles are shown on one layer (on the left hand side) and on two layers with hydrogen bonds (on the right hand side). (A) The IMGT Collier de Perles of a V-DOMAIN is based on the IMGT unique numbering for V-DOMAIN and V-LIKE-DOMAIN [16]. The CDR-IMGT are limited by amino acids shown in squares, which belong to the neighbouring FR-IMGT. The CDR3-IMGT extends from position 105 to position 117. CDR-IMGT regions are colored as follows on the IMGT site: CDR1-IMGT (blue), CDR2-IMGT (bright green), CDR3-IMGT (dark green) and hydrogen bonds are shown as green lines. (B) The IMGT Collier de Perles of a C-DOMAIN is based on the IMGT unique numbering for C-DOMAIN and C-LIKE-DOMAIN [17]. Amino acids are shown in the one-letter abbreviation. Arrows indicate the direction of the beta strands that form the two beta sheets of the immunoglobulin fold [3, 4]. Hatched circles correspond to missing positions according to the IMGT unique numbering [16, 17]. In the IMGT Collier de Perles on the IMGT Web site hydrophobic amino acids (hydropathy index with positive value) and Tryptophan (W) found at a given position in more than 50 % of analysed IG and TR sequences are shown in blue, and all Proline (P) are shown in yellow.

Figure 3

IMGT Colliers de Perles of the two G-DOMAINs of MHC class I (A) and of MHC class II (B) proteins (codes PDB 1bd2 and 1aqd, respectively, in IMGT/3Dstructure-DB [9]). The IMGT Collier de Perles of a G-DOMAIN is based on the IMGT unique numbering for G-DOMAIN and G-LIKE-DOMAIN [18]. (A) The two MHC-I G-DOMAINs, G-ALPHA1 (top) and G-ALPHA2 (bottom), form the groove of the MHC class I chain (I-ALPHA). (B) The two MHC-II G-DOMAINs, G-ALPHA (top) of the MHC class II alpha chain (II-ALPHA) and G-BETA (bottom) of the MHC class II beta chain (II-BETA), form the groove of the MHC class II protein [36]. Amino acids are shown in the one-letter abbreviation. Hatched circles correspond to missing positions according to the IMGT unique numbering [18]. Positions in colour correspond to the IMGT contact sites provided, for each peptide/MHC 3D structure, in IMGT/3Dstructure-DB [36].