ILC2 cells promote lung cancer and accumulate in tumors concomitantly with immune-suppressive cells in humans and mice

Abstract

It is now clear that group 2 innate lymphoid cells (ILC2) play crucial and sometimes opposing roles in the lung, such as restoring barrier function and integrity after viral infections or, on the contrary, exacerbating inflammation and tissue damage in allergic asthma. However, their role in lung cancer is still unclear. Here, we report that human non-small cell lung cancer patients bear increased frequencies of ILC2s in tumors, normal lung tissue and peripheral blood (PB) as compared to PB from healthy donors (HDs). Frequencies of Foxp3+ regulatory T cells were also increased in NSCLC patients, concomitantly with ILC2s. In mice bearing heterotopic lung cancer, adoptive transfer of ILC2s led to increased tumor growth and reduced survival. The frequencies of monocytic myeloid-derived suppressor cells (M-MDSCs) were found to be increased in the tumors of mice that received ILC2s as compared to controls. Overall, our results indicate that ILC2 cells play a pro-tumoral role in lung cancer potentially by recruiting immune-suppressive cells to the tumors.