IL-33 enhances LPS-mediated cytokine production by macrophages.

<p>TGC-induced peritoneal macrophages derived from B6J-WT mice (A–D) and B6N-WT and -IL-33^−/− mice (E) were cultured in the presence and absence of 100 ng/ml LPS, with and without 100 ng/ml IL-33, for 9, 24 and/or 48 h. (A, E) The levels of IL-6 in the culture supernatants by ELISA. (B) The percentage of PI-positive cells by flow cytometry. (C) LDH levels in the culture supernatants. (D) The number of IL-33-secreting cells by ELISPOT. Data show the mean +/± SEM (n = 3 [A] or 4 [B–E]). *p<0.05 vs. the indicated group (A) or Medium (B–E), and ^†p<0.05 vs. 24 h (C, D) or WT (E). P+I = PMA+ionomycin.