Nano- and Microparticle-Induced Cell Death, Inflammation and Immune Responses

Nano- and microparticles including crystals, synthetic biomaterials, misfolded proteins or environmental particulates are involved in a wide range of biological processes and diseases. They may present as intrinsic or environmental toxins but may also be applied intentionally, e.g. as immune adjuvants, drug carriers or ion exchangers. The discovery that a wide range of nano- and microparticles share the capacity to induce IL-1β secretion via activation of the NLRP3 inflammasome in dendritic cells and macrophages has led to the hypothesis that nano- and microparticles may contribute in a uniform mechanistic manner to different disease entities. Other molecular mechanisms triggered by a range nano- and microparticles have also recently been identified including (i) the induction of regulated necrosis; (ii) neutrophil extracellular trap (NET) formation and (iii) foreign body granuloma formation as a mechanism of persistent tissue inflammation and scarring. Research on the biology of nano- and microparticle handling is currently under intense investigation. The cell type-specific responses of nano- and microparticle exposure deserves careful attention as well as the related secondary responses to these particles that lead to tissue remodeling. The immune system is at the center of these processes in terms of particle clearance, particle-induced cell death and inflammation, thereby limiting particle-related inflammation and orchestrating wound healing responses. In this Research Topic, we welcomed the submission of Original Research, Review and Mini-Review articles that addressed the significance of the immune system in particle-induced cell death, inflammation and immune responses. These findings will help facilitate new approaches to the prevention and management of particle-related diseases.