Molecular recognition of lipid antigens by T cell receptors.
J Exp Med
; 189(1): 195-205, 1999 Jan 04.
Article
em En
| MEDLINE
| ID: mdl-9874576
ABSTRACT
The T cell antigen receptor (TCR) mediates recognition of peptide antigens bound in the groove of major histocompatibility complex (MHC) molecules. This dual recognition is mediated by the complementarity-determining residue (CDR) loops of the alpha and beta chains of a single TCR which contact exposed residues of the peptide antigen and amino acids along the MHC alpha helices. The recent description of T cells that recognize hydrophobic microbial lipid antigens has challenged immunologists to explain, in molecular terms, the nature of this interaction. Structural studies on the murine CD1d1 molecule revealed an electrostatically neutral putative antigen-binding groove beneath the CD1 alpha helices. Here, we demonstrate that alpha/beta TCRs, when transferred into TCR-deficient recipient cells, confer specificity for both the foreign lipid antigen and CD1 isoform. Sequence analysis of a panel of CD1-restricted, lipid-specific TCRs reveals the incorporation of template-independent N nucleotides that encode diverse sequences and frequent charged basic residues at the V(D)J junctions. These sequences permit a model for recognition in which the TCR CDR3 loops containing charged residues project between the CD1 alpha helices, contacting the lipid antigen hydrophilic head moieties as well as adjacent CD1 residues in a manner that explains antigen specificity and CD1 restriction.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Antígenos de Linfócitos T
/
Linfócitos T
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Lipídeos
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Antígenos
Limite:
Animals
/
Humans
Idioma:
En
Revista:
J Exp Med
Ano de publicação:
1999
Tipo de documento:
Article
País de afiliação:
Estados Unidos