Fig. 6.

MPL/TDCM-induced B1 cell activation, proliferation, ASC differentiation, and production of tumor-reactive IgM are dependent on TLR4 and TRIF signaling. Purified peritoneal B1 cells from WT, TLR4^−/− and TRIF^−/− mice were cultured in medium alone or with MPL/TDCM + squalene. On day 6, CD86 upregulation (a), cell yield (b), surface IgM and MHC class II expression (c), and CD138⁺ and CD138^hi B cell yields (d) were assessed by flow cytometry. e TA3-Ha-reactive IgM was detected in supernatants of cultured B1 cells using flow cytometry. Asterisks (*) indicate significant differences between medium cultures of the same genotype and hashtags (#) indicate differences between WT values (p < 0.05). Results representative of 3 independent experiments