Androgens protect murine ILC2 cells from functional suppression during influenza virus infection

Lung-resident group 2 innate lymphoid cells (ILC2s) produce type 2 cytokines and facilitate tissue repair in response to alarmins such as IL-33 released during respiratory virus infection, but they also may be functionally suppressed by type 1 cytokines. Compared to females, males harbor significantly fewer lung ILC2s, which express notably high levels of androgen receptor (AR) compared to other lymphocytes. Here we tested the hypothesis that females and males show differential ILC2 responses upon influenza virus (IAV) infection of mice. Over the course of sublethal infection, lungs of female mice contained greater numbers of ILC2s and ILC1s compared to males. However, the female ILC2s were preferentially suppressed at the peak of infection, with a dampened type 2 program manifest as attenuated proliferation, decreased propensity to produce IL-5 and amphiregulin, and reduced expression of GATA3 and IL-33R. Naïve female ILC2s showed higher expression of IFNGR and higher phospho-STAT1 levels following stimulation by IFN, and lymphocyte-restricted STAT1 deficiency reversed suppression of female ILC2s during infection. ILC2s in naive male mice with lymphocyte-restricted AR deficiency displayed levels of IFNGR comparable to female mice, suggesting AR activity underlies sex differences in intrinsic IFNGR expression. Early life orchiectomy or lymphocyte-restricted loss of AR revealed that endogenous androgens decreased ILC2 numbers but protected males from suppression of ILC2s in IAV infection. In sum, intrinsic AR activity preserves canonical ILC2 function in males during IAV infection, which may contribute to the sex differences in morbidity secondary to IAV observed in mice and humans. Female and male mice were infected with PR8 virus intranasally, and lungs were harvested at day 7 p.i. Lung ILCs were pooled from 4-5 female or male mice and sorted as lineage-negative (CD3, CD5, TCRβ, B220, CD11b, CD11c, TER119, Gr-1, CD19) CD90+IL-7Rα+ cells using a BD FACS Aria II instrument. Female and male ILCs were tagged with distinct Totalseq anti-mouse Hashtag (1 and 2) mAbs (anti-CD45 and MHCI) (Biolegend) to facilitate separation of the ILCs by sex in the sequencing analysis.