Related Experiment Videos
Antigen-presenting function of the TL antigen and mouse CD1 molecules
H Cheroutre1, H R Holcombe, S Tangri
1UCLA Department of Microbiology & Immunology 90095, USA.
Immunological Reviews
|October 1, 1995
Summary
Nonclassical antigen-presenting molecules like TL antigen and mCD1 may present distinct ligands. Their unique structures and expression on intestinal epithelial cells suggest roles in immune sampling and oral tolerance induction.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- Nonclassical antigen-presenting molecules, including TL antigen and mCD1, are characterized by a lack of polymorphism, suggesting specialized antigen-presenting functions.
- Unlike classical MHC molecules, these nonclassical molecules may present nonpeptide antigens or invariant peptides, such as those derived from heat shock proteins or modified peptides.
Purpose of the Study:
- To investigate the potential antigen-presenting functions of the TL antigen and mCD1, focusing on the types of ligands they present.
- To explore the biological roles of TL antigen and mCD1, particularly in the context of their expression on intestinal epithelial cells and their independence from TAP transporters.
Main Methods:
- Structural analysis of TL antigen and mCD1 to infer ligand-binding capabilities.
- Investigation of ligand-binding motifs for mCD1, contrasting with classical class I molecules.
- Examination of the expression patterns of TL antigen and mCD1 on intestinal epithelial cells and their TAP transporter dependency.
Main Results:
- Structural features of TL antigen suggest it can present nanomeric peptides, similar to classical class I molecules.
- mCD1 presents relatively long peptides with a distinct motif, though nonpeptide ligands remain a possibility.
- Both TL antigen and mCD1 are expressed by intestinal epithelial cells and can reach the cell surface without a functional TAP transporter.
Conclusions:
- TL antigen and mCD1 likely present different types of ligands, with TL antigen potentially binding peptides and mCD1 binding longer peptides or nonpeptide structures.
- The expression of TL antigen and mCD1 on intestinal epithelial cells suggests a role in sampling lumenal antigens for presentation to the immune system.
- These nonclassical molecules may contribute to immune responses or, more likely, the induction of systemic oral tolerance to peptide antigens.