Introduction: The new subset of T helper cells, known as Th17, has been reported toplay roles in tumor immunity. Tumor draining lymph nodes (TDLNs) are crucial inantitumor immune responses. To reveal the role of
Th17 in breast cancer patients, inpresent study, we focused on the frequency of these cells in tumor draining lymphnodes of patients with breast cancer.Subjects and methods: Sentinel and auxiliary lymph nodes (with or withoutinvolvement) were collected from 32 untreated breast cancer underwent surgicalresection. Mononuclear cells were isolated from fresh homogenized lymph nodes andstimulated with PMA/Ionomycin in the presence of protein transport inhibitors. Aftersurface staining for CD4, fixation and permeabilization, cells were incubated withanti-IL17a and appropriate matched negative controls. Data were acquired on fourcolorFACS Calibur flow cytometer and analyzed by CellQuestPro software. Thefrequency of IL-17 producing cells was demonstrated as a percentage of CD4 positivelymphocytes.Results: The percentage of
Th17 lymphocytes in TDLNs was 1.18 ± 0.62%. Themean florescent intensity of IL-17 expression in
Th17 cells was 15.27 ± 4.23 vs. 11.08± 3.10 in patients with free and involved lymph nodes, and 15.45 ± 4.02 vs. 9.40 ±2.62 in stage2 and 3, respectively. Although no difference was observed in frequencyof
Th17 cells in different pathological conditions, our data showed that intracellularproduction of IL-17 by CD4+ lymphocytes is significantly decreased in patients withtumor-involved lymph nodes compared to ones with free lymph nodes (P=0.015), andalso in patients who are in advance stages of breast cancer (P=0.026).Conclusion: Our results suggest that
Th17 cell percentage in TDLNs might beassociated with better prognosis in patients with breast cancer. These findings mayhave implication in immunotherapy targeting
Th17 cells in breast cancer.