Figure 6.

Resident macrophages phagocytize needle-like mesotheliomagenic particles (CNT-7), die rapidly (macrophage disappearance reaction or MDR) and release pyroptosis-related inflammatory cytokines (IL-1β, IL-6, and IL-17A) and chemokines (GRO/KC) to recruit neutrophils and alert the immune system. Released M-CSF and CCL2 chemokines also recruit bone marrow-derived monocytes, which then differentiate into MHCII^high small peritoneal macrophage (SPM-like) to replenish the empty macrophage niche. These monocyte-derived macrophages after CNT-7 may contribute to mesothelioma by preventing T cell killer activity. A MDR is also observed after phagocytosis of non-mesotheliomagenic tangled particles (CNT-T) but in a non-inflammatory environment. In this case, the replenishment of the cavity relies firstly on myeloid monocyte differentiation and later on proliferating MHCII^low large peritoneal macrophages (LPM).