| First Author | Tompkins SM | Year | 1998 |
| Journal | J Exp Med | Volume | 188 |
| Issue | 5 | Pages | 961-71 |
| PubMed ID | 9730897 | Mgi Jnum | J:115203 |
| Mgi Id | MGI:3690839 | Doi | 10.1084/jem.188.5.961 |
| Citation | Tompkins SM, et al. (1998) Transporters associated with antigen processing (TAP)-independent presentation of soluble insulin to alpha/beta T cells by the class Ib gene product, Qa-1(b). J Exp Med 188(5):961-71 |
| abstractText | T cell hybridomas isolated from nonresponder H-2(b) mice immunized with pork insulin were stimulated by insulin in the presence of major histocompatibility complex (MHC)-unmatched antigen presenting cells. The restriction element used by these CD4(-) T cells was mapped to an oligomorphic MHC class Ib protein encoded in the T region and identified as Qa-1(b) using transfectants. The antigenic determinant was localized to the insulin B chain, and experiments with truncated peptides suggested that it is unexpectedly long, comprising most or all of the 30 amino acid B chain. The antigen processing pathway used to present insulin to the Qa-1(b)- restricted T cells does not require transporters associated with antigen processing (TAP), and it is inhibited by chloroquine. A wide variety of cell lines from different tissues efficiently present soluble insulin to Qa-1(b)-restricted T cells, and insulin presentation is not enhanced by phagocytic stimuli. Our results demonstrate that Qa-1(b) can function to present exogenous protein to T cells in a manner similar to MHC class II molecules. Therefore, this class Ib protein may have access to a novel antigen processing pathway that is not available to class Ia molecules. |
