# Phenotype and function of IL-10–producing NK cells in individuals with malaria experience

## TL;DR

This study shows that natural killer (NK) cells from people with malaria experience produce more IL-10, which may help reduce inflammation and protect against malaria symptoms.

## Contribution

The study identifies a signature of IL-10–producing NK cells in malaria-experienced individuals and links it to potential protective immunity.

## Key findings

- NK cells from malaria-experienced individuals produce significantly more IL-10 than those without malaria experience.
- A signature of adaptive and checkpoint molecules was identified on IL-10–producing NK cells.
- Coculture with infected red blood cells and antibodies induced IL-10 production by NK cells.

## Abstract

P.falciparum infection can trigger high levels of inflammation that lead to fever and sometimes severe disease. People living in malaria-endemic areas gradually develop resistance to symptomatic malaria and control both parasite numbers and the inflammatory response. We previously found that adaptive NK cells correlated with reduced parasite load and protection from symptoms. We also found that murine NK cell production of IL-10 protected mice from experimental cerebral malaria. Human NK cells can also secrete IL-10, but it is unknown what NK cell subsets produce IL-10 or if this is affected by malaria experience. We hypothesized that NK cell immunoregulation may lower inflammation and reduce fever induction. Here, we showed that NK cells from participants with malaria experience make significantly more IL-10 than participants with no malaria experience. We then determined the proportions of NK cells that are cytotoxic and produce IFN-γ and/or IL-10 and identified a signature of adaptive and checkpoint molecules on IL-10–producing NK cells. Lastly, we found that coculture with primary monocytes, Plasmodium-infected RBCs, and antibody induced IL-10 production by NK cells. These data suggest that NK cells may contribute to protection from malaria symptoms via IL-10 production.

Natural kill cell immunosuppressive IL-10 production signature where IL-10 is significantly increased in malaria experienced individuals. This NK cell IL-10 may help protect against malaria.