High IL-13 production by human neonatal T cells: neonate immune system regulator?

Neonates are highly susceptible to diseases and display biased type 2 immun e responses, although no skewing to type 2 cytokines has been reported. In view of the emerging importance of IL-13 in type 2 inflammatory responses a nd clinical allergy, we analyzed IL-13 production by neonatal T cells. We f ound that, mainly CD8 T cells produced high levels of IL-13, while producin g low levels of IL-4, IL-10 and IFN-gamma, upon primary and secondary stimu lation. Our results point towards a possible immunoregulatory role of CD8 T cells in neonate responses. Moreover, they suggest that the abundance of I L-13 in the neonate immune system might account for the type 2 bias in neon ates, providing a basis for the high disease susceptibility of newborns, fo r instance to allergic diseases.