IL1B and listeriosis: Because IL-1β production is suppressed in L. monocytogenes-infected Clec5a−/− macrophages (Fig. 1c, d), we concluded that the induction of IL-17A-secreting CD3+CD4−TCRγδ+ population during Listeria infection occurs via CLEC5A-dependent IL-1β production from myeloid cells, rather than direct activation of CD3+CD4−TCRγδ+ cells.