. 2021 Sep 16;12:731100. doi: 10.3389/fimmu.2021.731100

Table 1.

Phenotypes of Tfh cell subsets in blood and lymphoid tissues.

Location	Cell subsets	Phenotypic markers	References
Blood
	Central memory Tfh cells	PD-1^-ICOS^-CCR7^highBcl-6^-Blimp-1^-CXCR5⁺	(32, 57, 58)
	Effector memory Tfh cells	CD40L⁺/PD-1⁺/ICOS⁺CCR7^lowBcl-6^-Blimp-1^-CXCR5⁺	(32, 57, 58)
	cTfh1 cells	IFN-γ⁺Bcl-6^-Blimp-1^-CXCR5⁺or PD-1⁺ICOS⁺CCR7^lowCXCR3⁺CCR6^-Bcl-6^-Blimp-1^-CXCR5⁺	(32, 57–59)
	cTfh2 cells	IL-4⁺Bcl-6^-Blimp-1^-CXCR5⁺ or CXCR3^-CCR6^-Bcl-6^-Blimp-1^-CXCR5⁺
	cTfh17 cells	IL-17A⁺Bcl-6^-Blimp-1^-CXCR5⁺or CXCR3^-CCR6⁺Bcl-6^-Blimp-1^-CXCR5⁺
	cTfh1/17 cells	IFN-γ⁺ IL-17A⁺Bcl-6^-Blimp-1^-CXCR5⁺or CXCR3⁺CCR6⁺Bcl-6^-Blimp-1^-CXCR5⁺
	cTfh13 cells	IL-13^hiIL-4^hiIL-5^hiIL-21^lowBcl-6⁺GATA3⁺CXCR5⁺	(72–74)
Lymphoid tissues
	Pre-Tfh cells	PD-1⁺ICOS⁺CCR7^lowBcl-6^lowBlimp-1^-CXCR5⁺	(32, 57, 58)
	GC Tfh cells	PD-1⁺⁺ICOS⁺⁺CCR7^-Bcl-6⁺Blimp-1^-CXCR5⁺⁺
	Memory Tfh cells	PD-1⁺ICOS⁺CCR7^lowBcl-6^lowBlimp-1^-CXCR5⁺

PD-1, programmed cell death protein-1; CCR7, CC-chemokine receptor 7; CXCR3, CXC-chemokine receptor 3; CCR6, CXC-chemokine receptor 6; CXCR5, CXC-chemokine receptor 5; ICOS, inducible T cell co-stimulator.