Innate immunity: two lines of defence
Type-2 immunity, the ancient defence mechanism that provides protection against gastrointestinal helminth infections, involves the recruitment of T helper (T
H
) cells that produce immune mediators or cytokines to coordinate an immune response involving IgE antibody production, the recruitment of eosinophils and goblet cell hyperplasia. Two groups reporting in this issue have characterized innate type 2 effector leukocyte populations that promote T
H
2 cytokine responses. Saenz
et al
. describe multipotent progenitor type-2 (MPP
type2
) cells that accumulate in response to the cytokine IL-25 (interleukin-25) and give rise to macrophage or granulocyte lineages promoting T
H
2 differentiation. Neill
et al
. describe 'nuocytes', induced by IL25 and IL33, which are the predominant early source of IL13 during a helminth infection. In News & Views, Gérard Eberl discusses how these two papers — and a third in
Nature Reviews Immunology
(
http://go.nature.com/sJ9D77
) — influence current thinking on the role of innate immunity.
Here, a new type of innate effector leukocyte cell — the nuocyte — is described and characterized. It is shown that interleukin (IL)25 and IL33 drive the expansion of the nuocyte population, that these cells secrete IL13, and that they are required for protection against helm...

Nuocytes represent a new innate effector leukocyte that mediates type-2 immunity

10.1038/nature08900