Skip to main content
. 2015 Jun 9;6:259. doi: 10.3389/fimmu.2015.00259

Figure 3.

Figure 3

Monocytes, and not T cells, from Cox-2flox/flox;LysMCre/+ mice enhanced the cytotoxic function of autologous NK cells and induced high levels of IFN-γ secretion. Wild type or Cox-2flox/flox; LysMCre/+ derived NK cells were activated with IL-2 (1 × 104 U/million) and cultured with either wild type or Cox-2flox/flox;LysMCre/+ monocytes for 7 days. Afterward, the cytotoxic function of NK cells against YAC-1 was determined using a standard 4 h 51Chromium release assay. The lytic units 30/106 cells were determined using inverse number of NK cells required to lyse 30% of the target cells × 100. *P < 0.05 is for the difference in cytotoxicity against YAC-1 tumors between IL-2-treated NK cells from control and Cox-2flox/flox;LysMCre/+ mice cultured with monocytes (A). NK cells were prepared as described in (A) and then supernatants from NK cell cultures were harvested after co-incubation with monocytes for 7 days. Monocytes from wild type and Cox-2flox/flox;LysMCre/+ mice were used as control. The levels of IFN-γ secretion were determined using specific ELISAs. *P < 0.05 is for the difference in IFN-γ secretion between IL-2-treated NK cells from control and Cox-2flox/flox;LysMCre/+ mice cultured with monocytes (B). NK cells were treated with IL-2 (1 × 104 U/million) and cultured with either T cells from global COX-2 knockout mice or monocytes from wild type or Cox-2flox/flox;LysMCre/+ mice for 7 days. Afterward, NK cells were used as effectors against wild type MEFs or MEFs with specific COX-2 deletion. The cytotoxic function of NK cells against MEFs was determined using a standard 4 h 51Cr release assay. The lytic units 30/106 cells were determined using inverse number of NK cells required to lyse 30% of the target cells ×100. *P < 0.05 is for the difference in cytotoxicity between IL-2-treated NK cells from control and Cox-2flox/flox;LysMCre/+ mice cultured with monocytes or T cells (C). IL-2-treated (1 × 104 U/million) NK cells obtained from wild type mice were cultured with monocytes from wild type mice or Cox-2flox/flox;LysMCre/+ mice for 7 days before the cells were used as effector cells in a standard 4 h 51Chromium release assay. Monocyte-derived DCs from wild type or Cox-2flox/flox;LysMCre/+ mice were prepared as described in Section “Materials and Methods” and used as target cells. The lytic units 30/106 cells were determined using inverse number of NK cells required to lyse 30% of the target cells × 100. *P < 0.05 was obtained for the difference in IL-2-treated NK cell-mediated lysis between DCs from control mice and from those of Cox-2flox/flox;LysMCre/+ mice (D). One of several representative experiments is shown in this figure.