Purification and Immunophenotypic Characterization of Human CD19⁺CD24^hiCD38^hi and CD19⁺CD24^hiCD27⁺ B Cells

Regulatory B cells (Bregs) have immunosuppressive capacity, primarily via the production of IL-10. IL-10 expression and immunosuppression have been described in a number of human B cell subsets, two of which include the CD19⁺CD24^hiCD38^hi and CD19⁺CD24^hiCD27⁺ populations. In this chapter, we describe how to identify and isolate these subsets from peripheral blood B cells via flow cytometry. We also explain how to expand Bregs in culture and how to identify them based on intracellular expression of IL-10.