The NLRP3 Inflammasome in inflammatory diseases: Cellular dynamics and role in granuloma formation

The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) and damage associated molecular patterns (DAMPs) through pattern recognition receptors (PRRs). Inflammasomes, cytoplasmic protein complexes, are activated in response to PAMPs and DAMPs, leading to the release of inflammatory cytokines such as IL-1β and IL-18. NLRP3 inflammasome is one of the best characterized inflammasomes and recently its activation has been associated with granuloma formation, structures that aggregate immune cells in response to infections, such as those caused by bacteria, fungi and parasites, and autoinflammatory diseases, such as sarcoidosis. Activation of NLRP3 inflammasomes in macrophages induces the release of cytokines that recruit immune cells, such as monocytes and lymphocytes, to the site of infection. Neutrophils, monocytes, T and B lymphocytes are important in the formation and maintenance of granulomas. Although NLRP3 plays a key role in the immune response, cell recruitment and granuloma formation, many aspects of its function in different cell types remain to be elucidated. In this review, we aim to outline the NLRP3 inflammasome not only as a protein complex that aids innate immune cells in combating intracellular pathogens but also as a platform with broader implications in orchestrating immune responses. This underexplored aspect of the NLRP3 inflammasome presents a novel perspective on its involvement in immunity. Thus, we review the current understanding of the role of the NLRP3 inflammasome in immune cell infiltration and its significance in the organization and formation of granulomas in inflammatory diseases.