A Retrospective Analysis of γδ T Cell Expression in Chronic Rhinosinusitis and Its Association with Recurrence of Nasal Polyps

Double-edged sword: γδ T cells in mucosal homeostasis and disease

The mucosa is a tissue that covers numerous body surfaces, including the respiratory tract, digestive tract, eye, and urogenital tract. Mucosa is in direct contact with pathogens, and γδ T cells perform various roles in the tissue. γδ T cells efficiently defend the mucosa from various pathogens, such as viruses, bacteria, and fungi. In addition, γδ T cells are necessary for the maintenance of homeostasis because they select specific organisms in the microbiota and perform immunoregulatory functions. Furthermore, γδ T cells directly facilitate pregnancy by producing growth factors. However, γδ T cells can also play detrimental roles in mucosal health by amplifying inflammation, thereby worsening allergic responses. Moreover, these cells can act as major players in autoimmune diseases. Despite their robust roles in the mucosa, the application of γδ T cells in clinical practice is lacking because of factors such as gaps between mice and human cells, insufficient knowledge of the target of γδ T cells, and the small population of γδ T cells. However, γδ T cells may be attractive targets for clinical use due to their effector functions and low risk of inducing graft-versus-host disease. Therefore, robust research on γδ T cells is required to understand the crucial features of these cells and apply these knowledges to clinical practices.

Interleukin-17A Expression Correlated with the Prognosis of Chronic Rhinosinusitis with Nasal Polyps and the Anti-Interleukin-17A Effect in a Murine Nasal Polyps Model

OBJECTIVE

To investigate the expression of interleukin-17A (IL-17A) in patients with chronic rhinosinusitis with nasal polyps (CRSwNP) and to analyze its effect on prognosis and to explore the role and mechanism of anti-IL-17A effect in vivo by establishing a murine nasal polyps (NP) model.

METHODS

Patients with CRSwNP who underwent endoscopic sinus surgery and matched control subjects were collected. We investigated IL-17A expression in human NP tissues using immunohistochemistry and analyzed their clinical features, including Lund-Mackay computed tomography scoring (LMCS) before surgery, Lund-Kennedy endoscopic scoring (LKES) before surgery (LKES B), LKES 6 months after surgery (LKES A), and reduction of LKES (LKES R). Then, after establishing the murine NP model to detect the expression and correlation of IL-17A and matrix metalloproteinase-9 (MMP-9) in nasal tissue, we studied nasal lavage fluid and serum by PCR and enzyme-linked immunosorbent assay in vivo. Anti-IL-17A treatment was administered in the murine NP model to confirm the function of IL-17A during the pathogenic processes.

RESULTS

IL-17A expression was upregulated in NP tissues from patients with CRSwNP compared with control subjects (p < 0.001). The number of IL-17A+ cells was significantly negatively correlated with LKES R in patients with CRSwNP (p < 0.01). However, there was no significant correlation between IL-17A and LMCS or LKES B (all p < 0.05). Further, IL-17A and MMP-9 were more abundant in nasal mucosa of the murine NP model compared with that of control mice (all p < 0.05), and severe polypoid lesions were apparently observed in murine NP models. Anti-IL-17A treatment downregulated the mRNA and protein expression of MMP-9 in nasal mucosa and reduced the number of polypoid lesions in the murine NP model (all p < 0.05).

CONCLUSION

Our results suggest that IL-17A plays a crucial role and may affect the prognosis of CRSwNP. Anti-IL-17A treatment may reduce the formation of polypoid lesions through inhibition of MMP-9 expression.

γδT cells contribute to type 2 inflammatory profiles in eosinophilic chronic rhinosinusitis with nasal polyps

Eosinophilic chronic rhinosinusitis with nasal polyps (ECRS) is a condition linked with type 2 inflammation, poor treatment outcomes, and high recurrence tendency. Although γδT cells have been reported to induce type 2 immune responses and eosinophilic infiltration in several diseases, their role in ECRS has not been fully explored. We aimed to evaluate the association of γδT cells with the type 2 inflammatory profiles in ECRS. Nasal tissue samples obtained from patients with chronic rhinosinusitis with nasal polyps (CRSwNP) (51 eosinophilic and 48 non-eosinophilic), 50 patients with chronic rhinosinusitis without nasal polyps (CRSsNP), and 58 control subjects were examined for γδT cells, inflammatory markers and eosinophils using HE, RT-qPCR, ELISA, immunofluorescence, and flow cytometry. In parallel, studies were also conducted in an ECRS murine model induced by anti-γδT cells neutralizing antibody administration. γδT cells expression was significantly increased in tissues from patients with ECRS compared with non-ECRS, CRSsNP and control subjects. Moreover, inflammatory markers including type 2 proinflammatory cytokines (IL-4, IL-5, IL-13), GATA3, eosinophil cationic protein (ECP), and eotaxin levels were also increased in nasal tissues of patients with ECRS, and Vγ1+ γδT cells mRNA expression was positively correlated with type 2 cytokines, GATA3, and ECP. In the ECRS murine model, anti-Vγ1+ γδT antibody treatment reduced the infiltration of eosinophils and expression of type 2 cytokines, GATA3, and ECP in nasal mucosae. In conclusion, the results of the present study suggest that γδT cells play a crucial role in the type 2 inflammatory profiles and nasal tissue eosinophilic infiltration in patients with ECRS.

Infiltration pattern of gammadelta T cells and its association with local inflammatory response in the nasal mucosa of patients with allergic rhinitis

BACKGROUND

gammadelta (γδ) T cells play important roles in allergic lower airway inflammation. However, little is known about their infiltration pattern in the nasal mucosa during upper airway inflammation. This study investigated γδ T cell distribution in nasal tissues of allergic rhinitis (AR) patients and the relationship between γδ T cells and other inflammatory cell types.

METHODS

A total of 30 patients with septal deviation were examined, including 22 with and 8 without AR. The localization of γδ T cells and other cells (eosinophils, neutrophils, mast cells, macrophages, B cells, cluster of differentiation [CD]4+ T cells, CD8+ T cells, regulatory T cells [Tregs], interferon [IFN]-γ+ cells, interleukin [IL]17+ cells, and IL10+ cells) was evaluated by histological analysis and immunohistochemistry. T helper cell (Th)1/Th2/Th17 and Treg gene expression was analyzed by quantitative polymerase chain reaction (PCR).

RESULTS

γδ T cells were localized in the epithelium or subepithelial region of nasal mucosa, and their infiltration was higher in AR patients relative to control subjects. The number of γδ T cells was associated with the presence of eosinophils, macrophages, mast cells, B cells, CD8+ T cells, Forkhead box (Fox)p3+ Tregs, IL17+ cells, and IL10+ cells but not of neutrophils or IFN-γ+ cells. The messenger RNA (mRNA) level of a γδ T cell subunit was positively correlated with those of Th1 genes (T-bet and IFN-γ), Th2 cytokine (C-C motif chemokine ligand 18), and Treg genes (Foxp3 and IL10).

CONCLUSION

γδ T cells play multiple roles in mucosal inflammation in AR including immune surveillance and adaptive and innate immune responses.