HLA-DR-presented peptide repertoires derived from @entity1 monocyte-derived dendritic cells pulsed with XXXX factor @entity797 .

@entity1 @entity2801 @entity797 @entity1003
Activation of T-helper cells is dependent upon the appropriate presentation of antigen-derived peptides on MHC class II molecules expressed on antigen presenting cells. In the current study we explored the repertoire of peptides presented on MHC class II molecules on @entity1 monocyte derived dendritic cells (moDCs) from four HLA-typed healthy donors. MHC class II-bound peptides could be routinely recovered from small cultures containing 5   10(6) cells. A fraction of the identified peptides were derived from proteins localized in the plasma membrane, endosomes, and lysosomes, but the majority of peptides that were presented on MHC class II originate from other organelles. Subsequently, we studied the antigen-specific peptide repertoire after endocytosis of a soluble antigen. @entity1003 factor @entity797 ( @entity2801 ) was chosen as the antigen since our current knowledge on MHC class II presented peptides derived from this immunogenic therapeutic protein is limited. Analysis of the total repertoire of MHC class II-associated peptides revealed that per individual sample 20-50 @entity2801 -derived peptides were presented on @entity2801 -pulsed moDCs. Repertoires of @entity2801 -derived peptides eluted from moDCs derived from a panel of four HLA typed donors revealed that some MHC class II-presented @entity2801 peptides were presented by multiple donors, whereas the presentation of other @entity2801 peptides was donor-specific. In total 32 different core peptides were presented on @entity2801 -pulsed moDCs from four HLA-typed donors. Together our findings provide an unbiased approach to identify peptides that are presented by MHC class II on antigen-loaded moDCs from individual donors.
