TABLE 1.
Treg Flow Cytometry Phenotyping Marker Guide
| Marker | Abbreviation | Surface or Intracellular Detection | Significance | T Cell Populations Expressing |
|---|---|---|---|---|
| Cluster of differentiation 3 | CD3 | S | Pan T cell marker | All T cells |
| Cluster of differentiation 4 | CD4 | S | CD4+ T cell marker | CD4+ T cells |
| Cluster of differentiation 25/IL2rα | CD25 | S | High affinity IL-2 receptor α, T and B cell growth factor (via IL-2 binding) (Fontenot et al., 2005; Lowenthal et al., 1985) | Tregs, some activated T cells (non-Tregs) |
| Forkhead box protein 3 | Foxp3 | IC | Master Treg transcription factor (Hori et al., 2003) | Tregs |
| Chemokine (CC-motif) receptor 6 | CCR6 | S | Lymphocyte chemoattractant CCL20 is its ligand (Schutyser et al., 2003) | Migratory Effector Tregs (Kleinewietfeld, et al., 2005; Yamazaki et al., 2008) and CD8+ T cells (Kondo et al., 2007) |
| Cluster of differentiation 103 | CD103 | S | Integrin involved in epithelial T cell migration and retention (Anz et al., 2011) | Migratory Effector Tregs (Matsushima and Takashima, 2010) and tissue resident CD8+ T cells (Mackay et al., 2013) |
| Cytotoxic T-Lymphocyte-Associated Protein 4 | CTLA4/CD152 | IC | Member of the CD28 family that is a potent inhibitor of T cell costimulation (Frauwirth and Thompson, 2002) | Tregs and activated T cells (non-Tregs) |
| Inducible T-cell costimulator | ICOS/CD278 | S | Member of the CD28 family that has costimulatory functionality during T cell activation (Hutloff et al., 1999) | Migratory Effector Tregs (Vocanson, et al., 2010) and activated T cells |
| Neuropilin-1 | Neuropilin-1 | S | Receptor for vascular endothelial growth factors and semaphorins (Gu et al., 2003) | nTregs (Weiss et al., 2012; Yadav et al., 2012), TFH cells (Renand et al., 2013), and CD8+ T cells (Jackson et al., 2014) |