IMGT Education

The Immune System: Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Antibodies (immunoglobulins, IG): proteins, expressed at the surface of a B cell or secreted by a plasma cell, which specifically bind to an antigen. When a soluble (circulating) antibody attaches to an antigen, it helps the body to destroy or inactivate that antigen.
Antigen: a substance or molecule against which the immune system acts. The antigen can be from foreign material such as bacteria or viruses or from self material.

B cells: small white blood cells crucial to the immune defenses. Also known as B lymphocytes they come from the bone marrow and develop into blood cells called plasma cells which are the source of circulating antibodies.
B cell epitope: part of the native structure of the antigen which is specifically recognized by an antibody.

CTL epitope: cytotoxic T cell epitope.
Cytotoxic T cell: a subset of T cells that carry a specific marker (CD8) and can destroy body cells infected by viruses or transformed by cancer.

Epitope: part of the antigen which is specifically recognized by an antibody (B cell epitope) or by a T cell receptor (T cell epitope).

Haplotypes: combinaison of linked alleles.
Helper T cells: a subset of T cells that carry the CD4 protein and increase immune responses by the secretion of specialized factors, the cytokines, that activate other white blood cells to fight off infection.
HLA: human leukocyte antigens or human MHC.

Major histocompatibility complex (MHC): proteins whose major function is to present to the T cells peptides resulting from the fragmentation, or processing, of antigenic proteins.

Proteasome: complex of proteases whose function is to fragment proteins into peptides.

TAP: transporter associated with antigen processing.
T cells: small white blood cells (also known as T Lymphocytes), comprise functional subsets: helper T cells (Th) , cytotoxic T cells (Tc) and Natural Killer T cells (NKT).
T cell epitope: part of the peptide (processed antigen) which is specifically recognized by a T cell receptor.
TR: T cell receptors, proteins expressed at the surface of T cells, that specifically recognize and bind a specific antigen presented by the MHC proteins and the CD1 MHC-like proteins.

See also:

Created: Monday, 22-Jun-2009 22:00:11 CEST
Author: Marie-Paule Lefranc
Editor: Chantal Ginestoux
Contact: Marie-Paule Lefranc

Software material and data coming from IMGT server may be used for academic research only, provided that it is referred to IMGT®, and cited as "IMGT®, the international ImMunoGeneTics information system® http://www.imgt.org (founder and director: Marie-Paule Lefranc, Montpellier, France)." References to cite: Lefranc, M.-P. et al., Nucleic Acids Research, 27, 209-212 (1999) Cover of NAR; Ruiz, M. et al., Nucleic Acids Research, 28, 219-221 (2000); Lefranc, M.-P., Nucleic Acids Research, 29, 207-209 (2001); Lefranc, M.-P., Nucleic Acids Res., 31, 307-310 (2003); Lefranc, M.-P. et al., In Silico Biol., 5, 0006 (2004) [Epub], 5, 45-60 (2005); Lefranc, M.-P. et al., Nucleic Acids Res., 33, D593-D597 (2005) Full text; Lefranc, M.-P. et al., Nucleic Acids Research 2009 37: D1006-D1012; doi:10.1093/nar/gkn838 Full text.
For any other use please contact Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr.

IMGT founder and director: Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr
Bioinformatics manager: Véronique Giudicelli Veronique.Giudicelli@igh.cnrs.fr
Computer manager: Patrice Duroux Patrice.Duroux@igh.cnrs.fr
Webmaster: Chantal Ginestoux Chantal.Ginestoux@igh.cnrs.fr