Innate Lymphoid Cells (ILC) are lymphocytes that share the same morphological features of classical lymphocytes. They lack specific antigen receptors (Spits and Cupedo Annu Rev Immunol 2012). The ILC family contains Natural Killer cells (NK), lymphoid tissue inducer (LTi) and other ILCs (Spits et al. Nat Rev Immunol 2013). A classification was proposed in which they divided the ILC family into three different groups based on their capacity to secrete cytokines (Spits et al. Nat Rev Immunol 2013). ILC group 1 is able to secrete IFN-g, ILC group 2 is able to secrete type 2 cytokines (IL5 and IL13) and ILC group 3 is able to secrete IL17 and/or IL22. ILC could also be classified by their expression of different membrane receptors. According to Mette and collaborators, the ILC are lineage negative, CD127+, and CD161+. The classification is made on CD117, CRTh2 and NKp44. ILC1 are CD117- CRTh2- and NKp44-. ILC2 are CD117+/- and CRTh2+. ILC3 are CD117+ and NKp44+/- (Mette et al Blood 2014).  In this presentation, we will propose a method to phenotype whole blood ILCs and PBMC ILCs. We will present how to use the new CytoFLEX flow cytometer to look into these different human classical ILC. We will also see how to calculate automatic compensations, and how to set carefully the different gates using fluorescence minus one tubes.

Learning Objectives:

• See a proposed method to phenotype whole blood ILCs and PBMC ILCs
• Learn how to use the new CytoFLEX flow cytometer to look into these different human classical ILC
• Learn how to calculate automatic compensations, and how to set carefully the different gates using fluorescence minus one tubes using the CytoFLEX flow cytometer