Effects of polypoid tissue on peripheral lymphocytes in a co-culture system

T cell subpopulations in nasal polyps differ from peripheral lymphocytes in patients of CRSwNP. These T cells crucially determine the phenotype of nasal polyps. However, there is little known about the modulatory influence of the inflamed nasal mucosa on the phenotype of the T cells. The aim of this study was to analyze this interaction.

Tissue and blood samples were collected from 10 patients undergoing paranasal sinus surgery. Polypoid tissue was cultured under air-liquid-interface conditions. Afterwards CD3/CD28 activated PBMC of the same patients were added. After 3 days, lymphocytes were separated from co-culture and analyzed by multicolor flow cytometry. As control group, PBMC were cultured in the same setting without the co-cultured polypoid tissue. Additionally, cytokine expression of the polyp tissue was measured using a human Th1/Th2/Th17 antibody array.

There was a significantly higher amount of CD4+and CD8+ T cells in the co-cultured system than in PBMC alone. Terminal differentiated CD8+ T cells were increased, while central memory CD8+ T cells decreased in the co-culture. HLA-DR was significantly downregulated on co-cultured CD3+ lymphocytes. Conventional memory CD4+ T cells increased and resting regulatory T cells decreased in the co-cultured system. Cytokine analysis showed an expression of Il-6, GMCSF and MIP-3. All results showed significance.

In this study, a reproducible effect of nasal polypoid tissue on PBMC was shown. Interestingly, the significant downregulation of HLA-DR on CD3+ lymphocytes was confirmed in vitro. The inhibitory effect of the polypoid tissue on the activation of lymphocytes is a possible pathomechanism of this disease.

Publication History

Publication Date:
18 April 2018 (online)