Article 1 Class II MHC multimers Class II MHC tetramers 1 Escherichia coli 1 HEK293 Cells 1 HEK293 cell line 1 HEK293T cell line 1 HLA DM antigen 1 HLA antigen class 2 1 Histocompatibility Antigens Class II 1 Humans 1 Indicators and Reagents 1 Lentivirus 1 Staining and Labeling 1 T lymphocyte 1 allele 1 amino terminal sequence 1 animal cell 1 antigen-specific T cells 1 beta chain 1 biotinylation 1 catalysis 1 controlled study 1 dyes, reagents, indicators, markers and buffers 1 elution 1 flow cytometry 1 gel electrophoresis 1 gene expression system 1 high throughput screening 1 human 1