HLA-DM- APC are unable to present soluble Ags to T cells in the context of class II DR molecules. This defect in DM- APC can be overcome by receptor-mediated delivery of Ag into cells. Ag conjugated to ligands for cell surface receptors, such as transferrin or goat anti-human Ig, was processed and presented by DM- T2.DR4 cells. Intracellular processing of Ag conjugates was required, as receptor cross-linking alone did not restore presentation by DM- APC. Ag conjugates targeted by transferrin receptors to endosomes or via surface Ig to endosomal and lysosomal compartments, were each efficiently presented by DM- cells. These Ag conjugates were predominantly localized in light density endosomes in T2.DR4 cells. This study demonstrates that the facilitated up- take and sorting of exogenous Ag by cell surface receptors allow efficient class II-restricted presentation even in the absence of HLA-DM.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Immunology|
|State||Published - Jan 1 1997|
ASJC Scopus subject areas
- Immunology and Allergy