Table 1.

In vitro studies of human neonatal T cells

	References
Contain high concentrations of TRECs	[10,11]
High cell turn-over	[10–14]
Have high constitutive telomerase activity and long telomeric sequences	[10]
Have increased susceptibility to apoptosis, prevented by cytokines signalling through the IL-2 receptor γ-chain	[11,14,16]
Proliferation induced by IL-7 and IL-15	[10,11,13,14,16,17,19,20]
Low production of IFN-γ by CD4 T lymphocytes associated with hypermethylation of IFN-γ promoter	[25,26,28]
Expression of CD40 ligand by CD4 T lymphocytes is controversial	[29,30,31,32,33,34,35]
Expression of NFAT by CD4 T lymphocytes is controversial	[36–38]
CD25+ regulatory T lymphocytes occur spontaneously during foetal life	[41–44]