Enrichment of Innate Lymphoid Cell Populations in Gingival Tissue

Abstract

Innate lymphoid cells (ILCs) are a population of lymphocytes that act as the first line of immunologic defense at mucosal surfaces. The ILC family in the skin, lungs, and gastrointestinal tissues has been investigated, and there are reports of individual subsets of ILCs in the oral tissues. We sought to investigate the whole ILC population (group 1, 2, and 3 subsets) in the murine gingivae and the lymph nodes draining the oral cavity. We show that ILCs made up a greater proportion of the whole CD45+ lymphocyte population in the murine gingivae (0.356% ± 0.039%) as compared with the proportion of ILCs in the draining lymph nodes (0.158% ± 0.005%). Cytokine profiling of the ILC populations demonstrated different proportions of ILC subsets in the murine gingivae versus the regional lymph nodes. The majority of ILCs in the draining lymph nodes expressed IL-5, whereas there were equal proportions of IFN-γ- and IL-5 expressing ILCs in the oral mucosa. The percentage of IL-17+ ILCs was comparable between the murine gingivae and the oral draining lymph nodes. These data suggest an enrichment of ILCs in the murine gingivae, and these ILCs reflect a cytokine profile discrepant to that of the local draining lymph nodes. These studies indicate diversity and enrichment of ILCs at the oral mucosal surface. The function of ILCs in the oral cavity remains to be determined; here, we provide a premise of ILC populations that merits future consideration in investigations of mouse models and human tissues.

γδT Cells Are Essential for Orthodontic Tooth Movement

“…While these populations are more evident during periodontitis, they might also be part of the αβ T-cell population identified in the current work. Furthermore, innate lymphocyte cells (ILCs) also have been reported to reside in the gingiva (Brown et al 2018), and while we did not classify them, they are likely part of our unidentified leukocytes in both tissues. ILCs might also represent the IL-17Aproducing cells in our ex vivo stimulation studies since they were reported to secrete this cytokine in the oral mucosa (Sparber et al 2018).…”

Innate Lymphoid Cells in Mucosal Immunity

“…Approximately 10–15% of total CD45 + cells identified were ILCs and most of them were IFN-γ secreting ILC1s (148). A recent study by Brown et al demonstrated the presence of all three groups of ILCs in the murine gingivae (149). ILC3s provided protection against oropharyngeal infection with Candida albicans through production of IL-17A and IL-17F induced by IL-23 (Figure 1) (72); thus, both Ror γ t −/− mice lacking ILC3s and mice depleted of ILC3s by antibody treatment suffered severe infection (72).…”

Group 1 innate lymphoid-cell-derived interferon-γ maintains anti-viral vigilance in the mucosal epithelium

“…In the oropharyngeal cavity, murine ILC1s reside in salivary glands (Cortez et al, 2016) and gingiva (Brown et al, 2018), although ILC1 function in oral health and oral mucosal defense remains to be determined. To investigate the mechanisms underlying the resilience of the oral mucosa against viral infection, we established a murine model of viral oral mucosal infection using the poxvirus vaccinia virus (VACV).…”