|
||
J. Exp. Med.,
Volume 189, Number 1, January 4, 1999 195-205
By


From the * Lymphocyte Biology Section, Division of Rheumatology, Immunology, and Allergy,
Department of Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston,
Massachusetts 02115; the 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
Department of Molecular Biology and Skaggs Institute of Chemical
Biology, Scripps Research Institute, La Jolla, California 92037; and the § Division of Dermatology,
University of California Los Angeles School of Medicine, Los Angeles, California 90095
and
chains of a single TCR which contact exposed residues of the peptide antigen and amino acids along the
MHC
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
helices. Here, we demonstrate that
/
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
helices, contacting the lipid antigen hydrophilic head moieties as
well as adjacent CD1 residues in a manner that explains antigen specificity and CD1 restriction.
This article has been cited by other articles:
| TABLE OF CONTENTS |
|