Fig. 4. Macrophage engulfment of dying cells.

Jurkat cells or FADD-DN Jurkat cells were triggered to undergo three different cell death modalities for 24 h using anti-Fas antibodies, TNF-α, and RSL3, respectively, and were then co-cultured for 1 h with primary human monocyte-derived macrophages. Non-engulfed cells were washed away and macrophages were collected, fixed, and processed for TEM. Shown here are images of control macrophages (a) and macrophages engulfing apoptotic (b), necroptotic (c), or ferroptotic (d) Jurkat cells. Scale bars represent 5, 10, or 20 µm. Note the presence of multiple, largely intact target cells with condensed chromatin in macrophages in (b) as opposed to the uptake of severely fragmented cells in (c) and (d)