The assembly of functional beta(2)-microglobulin-free MHC class I molecules that interact with peptides and CD8(+) T lymphocytes.
Functional MHC class I molecules are expressed on the cell surface in the absence of beta(2)-microglobulin (beta(2)m) light chain that can interact with CD8(+) T lymphocytes. Whether their assembly requires peptide binding and whether their recognition by CD8(+) T lymphocytes involves the presentation of peptide epitopes remains unknown. We show that beta(2)m-free H-2D(b) assembles with short peptides that are approximately 9 amino acid residues in length, akin to ligands associated with completely assembled beta(2)m(+) H-2D(b). Remarkably, a subset of the peptides associated with the beta(2)m-free H-2D(b) has an altered anchor motif. However, they also include peptides that contain a beta(2)m(+)H-2D(b) binding anchor motif. Further, the H-2K(b)- and H-2D(b)-restricted peptide epitopes derived from SV-40 T antigen also assemble with H-2(b) class I in beta(2)m-deficient cells and are recognized by epitope-specific CD8(+) T lymphocytes. Taken together our data reveal that functional MHC class I molecules assemble in the absence of beta(2)m with peptides and form CD8(+) T lymphocyte epitopes.
Schell
Todd D
TD
Department of Microbiology and Immunology, Pennsylvania State University, College of Medicine, Hershey, PA 17033, USA.
Mylin
Lawrence M
LM
Tevethia
Satvir S
SS
Joyce
Sebastian
S
D000818:Animals; D017951:Antigen Presentation; D000952:Antigens, Polyomavirus Transforming / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D002460:Cell Line; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D006183:H-2 Antigens / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000276:immunology*; D051379:Mice; D010455:Peptides / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic; D001613:beta 2-Microglobulin / Q000172:deficiency*
D000952:Antigens, Polyomavirus Transforming; D018984:Epitopes, T-Lymphocyte; D006183:H-2 Antigens; D015395:Histocompatibility Antigens Class I; D010455:Peptides; D001613:beta 2-Microglobulin