Immunological characteristics of CD103+CD161+ T lymphocytes on chronic rhinosinusitis with nasal polyps

Chronic rhinosinusitis with nasal polyps (CRSwNPs) is a heterogeneous disease characterized by local inflammation of the upper airway and sinus mucosa. T cell-mediated immune responses play irreplaceable roles in the pathogenesis of nasal polyps. CD161⁺ T cells have been implicated in the pathology of several diseases through cytokine production and cytotoxic activity. However, the immunological characteristics of CD161⁺ T cells in nasal mucosa are still not well understood, particularly in CRSwNPs. Our research revealed a notable enrichment of CD161⁺ T cells in nasal tissues compared to peripheral blood, with a significantly more infiltration of CD161⁺ T cells in CRSwNPs compared to control nasal samples. Phenotypical analysis found that CD161⁺ T cells predominantly co-expressed tissue-resident memory surface markers CD103, CD69, and CD45RO. CD161⁺CD103⁺ T cells demonstrated complicated effector functions, marked by elevated levels of PD-1, CTLA-4, IL-17, and IFN-γ and diminished expression of FoxP3 and CD25. Interestingly, despite CD161⁺ T cells was more abundant in polyp tissues compared to normal control tissues, and then further categorizing polyp samples into distinct groups based on clinical characteristics, only the recurrent CRSwNP group showed a significant reduction in CD161⁺CD8⁺ T cells compared to the primary CRSwNP group. This finding suggested the necessity for further research to comprehensively understand the underlying mechanisms and the broader significance of CD161⁺ T cells in the advancement and relapse of CRSwNPs.