Short CommunicationNeutrophil microparticles modulate cytokine production by natural killer cells

- Neutrophil microparticles suppress IFN-γ and TNF-α production by NK cells.
- Neutrophil microparticles enhance TGF-β1 production by NK cells.
- Phosphatidylserine mediates the effects of neutrophil microparticles on NK cells.

Neutrophil microparticles (NMs) are scarce in the circulation but are highly enriched at sites of inflammation and exert profound effects on immune cells. In the present study, we addressed whether NMs modulate cytokine-producing capacity of natural killer (NK) cells. NMs inhibited the production of IFN-γ and TNF-α but enhanced the release of TGF-β1 by IL-2/IL-12-activated NK cells. The inhibitory effect of NMs was strongly attenuated by blockade of phosphatidylserine exposed on NMs. Thus, NMs skew the cytokine profile of NK cells from pro-inflammatory toward anti-inflammatory, potentially favoring the resolution of inflammation.