Stage 3 immature human natural killer cells found in secondary lymphoid tissue constitutively and selectively express the TH17 cytokine interleukin-22

T Hughes, B Becknell, S McClory… - Blood, The Journal …, 2009 - ashpublications.org
T Hughes, B Becknell, S McClory, E Briercheck, AG Freud, X Zhang, H Mao, G Nuovo, J Yu
Blood, The Journal of the American Society of Hematology, 2009ashpublications.org
Considerable functional heterogeneity within human natural killer (NK) cells has been
revealed through the characterization of distinct NK-cell subsets. Accordingly, a small subset
of CD56+ NKp44+ NK cells, termed NK-22 cells, was recently described within secondary
lymphoid tissue (SLT) as IL-22− when resting, with a minor fraction of this population
becoming IL-22+ when activated. Here we discover that the vast majority of stage 3
immature NK (iNK) cells in SLT constitutively and selectively express IL-22, a TH17 cytokine …
Abstract
Considerable functional heterogeneity within human natural killer (NK) cells has been revealed through the characterization of distinct NK-cell subsets. Accordingly, a small subset of CD56+NKp44+NK cells, termed NK-22 cells, was recently described within secondary lymphoid tissue (SLT) as IL-22 when resting, with a minor fraction of this population becoming IL-22+ when activated. Here we discover that the vast majority of stage 3 immature NK (iNK) cells in SLT constitutively and selectively express IL-22, a TH17 cytokine important for mucosal immunity, whereas earlier and later stages of NK developmental intermediates do not express IL-22. These iNK cells have a surface phenotype of CD34CD117+CD161+CD94, largely lack expression of NKp44 and CD56, and do not produce IFN-γ or possess cytolytic activity. In summary, stage 3 iNK cells are highly enriched for IL-22 and IL-26 messenger RNA, and IL-22 protein production, but do not express IL-17A or IL-17F.
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