. 2023 Jan 13;24(2):1564. doi: 10.3390/ijms24021564

Table 1.

Characteristics of skin T_RM and recirculating CD8 T cells.

Characteristic		T_RM Cells	Recirculating Cells	Ref.
Trafficking property		Skin-resident	Skin-transient	[10]
Percentage (%) of CD8 T cells in healthy human skin	Epidermis	25%	<5%	[51]
Percentage (%) of CD8 T cells in healthy human skin	Dermis	13%	<5%	[51]
Surface markers in skin		CD103^+/−CD69⁺CD49a^+/−	CD69⁻	[58]
Requirement for persistency in skin		TGF-β, IL-15/IL-7	TGF-β, IL-15	[56,74,75]
Effector function		CD103⁺ > CD103⁻	Limited	[51,76]
Proliferative capacity		CD103⁻ > CD103⁺	T_CM > T_EM	[51,76]
Antiviral protection		Critical for secondary infection	Required for optimal response	[77]

Abbreviations: T_RM cells, tissue memory T cells; TGF-β, transforming growth factor-β; IL, interleukin; T_CM, central memory T cells; T_EM, effector memory T cells.