Function of Innate Lymphoid Cells in Periodontal Tissue Homeostasis: A Narrative Review

Abstract

Periodontitis is an irreversible inflammatory response that occurs in periodontal tissues. Given the size and diversity of natural flora in the oral mucosa, host immunity must strike a balance between pathogen identification and a complicated system of tolerance. The innate immune system, which includes innate lymphoid cells (ILCs), certainly plays a crucial role in regulating this homeostasis because pathogens are quickly recognized and responded to. ILCs are a recently discovered category of tissue-resident lymphocytes that lack adaptive antigen receptors. ILCs are found in both lymphoid and non-lymphoid organs and are particularly prevalent at mucosal barrier surfaces, where they control inflammatory response and homeostasis. Recent studies have shown that ILCs are important players in periodontitis; however, the mechanisms that govern the innate immune response in periodontitis still require further investigation. This review focuses on the intricate crosstalk between ILCs and the microenvironment in periodontal tissue homeostasis, with the purpose of regulating or improving immune responses in periodontitis prevention and therapy.

An update on periodontal inflammation and bone loss

“…In humans, the percent ILCs were not significantly altered in the gingiva of subjects with periodontitis. Notably, a small proportion of ILC1 cells expressed RANKL and and ILC3 produced IL17A suggesting they could participate in bone resorption ( 71 ). The plasticity, differentiation, tissue-specific migration and accumulation of ILC subpopulations may be an important modulator of the local immune response ( 72 ).…”

Exploring the role of innate lymphoid cells in the periodontium: insights into immunological dynamics during orthodontic tooth movement

“…Despite understanding that ILCs play a role in sterile inflammatory responses across different tissues, their involvement in sterile inflammation within periodontal tissues remains uncertain. To our knowledge, only a limited number of studies have been published thus far highlighting the presence of ILCs in periodontal tissues, with two investigations indicating their role in immune response regulation in periodontitis ( 17 , 22 – 24 ). However, research on the dynamics of ILCs during OTM and their specific impact on sterile inflammation induced by mechanical stress is still lacking.…”