Up-regulation Of Interleukin-17-producing CD4~+ T Helper Lymphocyte And Infiltrative Mechanism In Malignant Pleural Effusion Of Lung Adenocacinoma

Objective To detect the proportion of CD4+IL-17+ T helper (Th17) lymphocyte in malignant pleural effusion (MPE) and peripheral blood (PB) of lung adenocacinoma patients. To detect the proportion of CCRs positive expression of Th17. And to investigate the chemotactic activity of associated CCLs in MPE in vitro in order to determine the mechanisms about the infiltration of Th17 into malignant pleural effusion.Methods The pleural effusion and peripheral blood samples were obtained from 14 patients of lung adenocacinoma with MPE. Peripheral blood samples were also obtained from 5 healthy donors (HD) as controls. Pleural effusion mononuclear cells (PEMCs) and peripheral blood mononuclear cells (PBMCs) were purified and stimulated. The percentages of Th17 and that of CCRs positive in Th17 were determined by four colors flow cytometry. CD4+IL-17+ T helper lymphocyte isolated from peripheral blood samples from 5 patients randomly were cultured in Transwell system to investigate the chemotactic activity of MPE, and the mediation of associated chemotactic axes in the infiltration of Th17 into MPE.Results (1) The increased percentages of CD4+IL-17+ T helper lymphocyte were observed from MPE samples(3.6793±0.50878%), significant higher than that of PB samples(0.5886±0.08524%)(P=0.000) and healthy donors (0.8320±0.21613%)(P=0.000). However, no significant statistical difference between PB of patients and PB of healthy donors was observed (P=0.212). (2) Th17 with high proportions of CCR4 (MPE 65.8615±2.35143%, PB 62.0886±2.49920%, HD 75.8560±6.13051%) and CCR6 molecules (MPE 48.2521±4.75612%, PB 38.6336±4.22941%, HD 54.6280±8.74540%) were detected in these three groups, and also with certain proportions of CCR2 (MPE 20.5564±2.67499%, PB 21.9757±2.16233%, HD 24.9160±4.56771%) and CCR5 molecules (MPE 26.8407±2.24145%, PB 24.7750±2.38923%, HD 22.5860±4.21803%). All the percentages positive of each CCR among these groups were without any statistical diversity (all P>0.05). (3) Directly chemotactic activity of MPE due to infiltration of peripheral blood Th17 into the pleural cavity was detected positively by Transwell system in vitro. The additions of anti-human-CCL20 (P=0.007) or anti-human-CCL22 (P=0.002) could lead to inhibition of this chemotaxis.Conclusions An up-regulation of proportions of Th17 in MPE of lung adenocacinoma patients were detected compared with PB and HD. Th17 constantly expressed CCR2, CCR4, CCR5, and CCR6 molecules, and no CCRs phenotype transformations were observed after the infiltration into malignant pleural effusion. MPE had the directly chemotactic activity attracting Th17 from PB infiltrating into pleural cavity. The CCR4--CCL22 axis and CCR6--CCL22 axis probably contributed to the chemotaxis.