Implication of IL-17 producing ɑβT and γδT cells in patients with ovarian cancer

Abstract

Objective: To investigate the expression and cellular source of IL-17A in human ovarian cancer (OC), benign ovarian tumor (BOT) and borderline ovarian tumor (OBT).

Methods: RT-PCR and immunohistochemistry were used to measure the expression level of IL-17A in human OC tissues. Find concrete source of the elevated IL-17A levels in OC tissues by flow cytometry.

Results: We found that IL-17A is expressed at higher levels in OC tissues than in BOT or OBT tissues at both the mRNA and protein levels. Moreover, high tumor IL-17A expression was significantly associated with poor tumor differentiation and positive lymph node status. Flow cytometric analysis demonstrated that significantly higher proportions of tumor-infiltrating IL-17A-producing CD4⁺ T cells (Th17), CD8⁺ T cells (Tc17), and γδT cells (IL-17⁺ γδT) were present in OC tissue compared with BOT tissue. Of these, tumor-infiltrating γδT cells were the predominant source of IL-17A in OC and BOT patients. Finally, we found that the abundance of tumor-infiltrating IL-17⁺ γδT cells, but not Th17 or Tc17 cells, was positively correlated with larger tumor size and lymph node metastasis in patients with advanced OC. These data suggest that increased tumor-infiltrating IL-17⁺ γδ T cells may be associated with cancer progression in OC patients.

Keywords: IL-17A; Inflammation; Ovarian cancer; γδT cells.