Histologic evaluation of lesional tissues reveals a significant increase of inflammatory cells associated with disease pathology (Fig. lymphoid cells SNT-207858 (ILC) policing the gingival barrier. We further characterize cellular subtypes in health and interrogate shifts in immune cell populations in the common oral inflammatory disease periodontitis. In Mouse monoclonal to MSX1 disease we document an increase in neutrophils and an up regulation of IL-17 responses. We identify the main source of IL-17 in health and periodontitis within the CD4+ T cell compartment. Collectively our studies provide a first view of the scenery of physiologic oral immunity and serve as a baseline for the characterization of local immunopathology. IFN- and IL-17A production by T cell subsets. Cells were stimulated using PMA/Ionomycin and frequencies of IFN/IL17 secreting cells was evaluated in CD4+, CD8+ and TCR+ cells. Representative plots shown (n=10). (b) Single/Live/CD45+ were evaluated for presence of Lineage specific markers Lin= (CD3?/CD19?/CD20?/CD1a?/CD11c?/CD14?/FcR1?/CD16?/CD34?) and Lin- cells were evaluated following activation for secretion of IFN/IL17 (representative plots shown, n=5). (c) Phenotypic analysis of the lineage unfavorable population. Lin-cells were evaluated for expression of CD127 (ILC marker). Lin-CD127? were evaluated for CD56 and NKp46. Lin-CD127+ cells were evaluated for CD161+, CRTH2, NKp44, NKp46. The ILC compartment in healthy gingiva To identify additional cytokine sources within the healthy tissue, we evaluated cytokine secretion from Innate lymphoid cells (ILCs). ILC constitute a family of mononuclear hematopoietic cells with important functions in barrier immunity and tissue repair 18. They are defined by their hematopoietic origin (designated by expression of CD45) and the absence of rearranged antigen-specific receptors and markers of specific lineage. With this definition in gingival tissues approximately 10-15% of CD45+ cells belong to the ILC compartment (Fig. 4b). Further ILC classification has been based on functional characteristics categorizing ILCs into 3 groups; ILC1 which include NK cells and produce IFN, ILC2 generating IL-5 and IL-13 and ILC3 generating IL-17 and/or IL-2218. Based on functional characteristics oral ILC belong primarily to the ILC1/NK group as they were largely IFN+ (Fig. 4b). We further defined ILC subsets in this tissue according to phenotypic characteristics based on proposed nomenclature for human ILC 19. Within the CD45+ cell portion approximately one third of the lineage unfavorable (CD3?/CD19?/CD20?/CD1a?/CD11c?/CD14?/FcR1?/CD16?/CD34?) cells were CD127+ and therefore considered non NK ILC. Two thirds of the lineage unfavorable cells were CD127?, a populace of cells largely positive for NK and the ILC1 markers CD56 and NKp46. Further investigation of CD127+ ILC highlighted that they expressed CD161 but not CRTH2, a marker specific for ILC2 nor NKp44 and CD117, markers specific for ILC3s. Thus, consistent with production of IFN (Fig 4c), gingival ILCs were presumed to belong primarily to the ILC1 group. Shifts in major cell populations in the oral disease periodontitis Having performed a detailed characterization of immune cell subsets at the gingival barrier in health, presumably participating in local homeostasis, we aimed to demonstrate that our studies may provide a baseline for the interrogating of pathologic immune responses involved in oral diseases. To this end, we performed a small scale study characterizing major shifts in immune cell populations encountered in the common oral disease periodontitis. Periodontitis is usually a microbe stimulated inflammatory disease, SNT-207858 which in its chronic form is one of the most common human inflammatory diseases7. The hallmark of periodontitis is usually immune-mediated destruction of tooth SNT-207858 supporting structures (including connective tissue and bone). To evaluate immune cell shifts with periodontitis we enrolled in our study a small cohort of severe-chronic periodontitis patients (Supplemental Table 2), who displayed severe bone loss, visible inflammation and.