Large scale preparation of human MHC class II+ integrin β1+ Tregs

The human CD4+CD25+FoxP3+ regulatory T cell population (Tregs) contains both MHC class II+ and MHC class II− cells. MHC class II+ Tregs belong to the integrin α4β1+ subpopulation and exclusively execute contact-dependent suppressive activity. Here we present a method optimized for isolation of these MHC class II expressing Tregs from large leukaphereses products using magnetic microbeads that achieves a reproducible purity of more than 90% and enables the use of this small-sized Treg population in pre-clinical application and basic research.