Table 2.

Relative abundance of lymphocytes within lymphocyte-rich tissues in humans, according to their maturation level.

		Repartition of median count within lymphocytes
			T-cell subsets (% among T cells)				B-cell subsets (% among B cells)
	% of Lymphocytes among total leukocytes	T cells	Progenitor or immature	CD4+	CD8+	B cells	Progenitor or immature	Memory	Plasma	NK cells	Ref.
Tonsil	NS	+	∼	++++	+	++	∼	+	+++++	+	(21)
Thymus	+++++	+++++	+++++	+	+	∼	∼	∼	∼	+	(22, 23)
Lymph node	+++++	++++	∼	+++	++	+	∼	∼	∼	+	(22, 23)
Lung	++	+++	∼	+++	++	+	∼	∼	++	+++	(24)
Liver	+	++	∼	++	+++	+	∼	∼	∼	+++	(25, 26)
Spleen	++++	++	∼	+	+	+++	∼	∼	∼	+	(22, 27)
Kidney	NS	+++	∼	+++	+++	+	∼	∼	∼	++	(23, 28)
Gut (Peyer)	NS	+++	∼	++++	+	+++	+	+	∼	+	(23, 29)
Blood	++	++++	∼	+++	+	++	∼	+++	+++	+
Bone marrow	+	+++	+++	++	++	+	+++++	∼	∼	+	(30)

Note: Green columns indicate the relative abundance of the main subpopulations of T or B lymphocytes among the complete cohorts of T or B cells (black columns).

Abbreviations: Negligible fraction, ∼; <20%, +; (20%–40%), ++; (40%–60%), +++; (60%–80%), ++++; >80%, +++++; NS, not specified.