Correlation of increased numbers of tumor-infiltrating T regulatory, CD19 and CD8 T cells in well differentiated oral squamous cell carcinoma

Abstract

Evidence from cancer patients suggests that increases in T-regulatory lymphocyte (Treg) activity may be associated with poor immune responses against tumor antigens, and contribute to immune dysfunction. Since there have been contradictory reports concerning the physiological roles of the Treg and inflammatory cells in the tumor microenvironment, the inflammatory cell influx was investigated for different malignancy
grades of oral squamous cell carcinoma (OSCC). A total of 42 patients with OSCC were selected. Tumors were histologically graded as well, moderately, or poorly differentiated. Tissue microarrays were performed to immunohistochemically measure the expression of CD8, Foxp3, CD19, and IL-10. Significant statistical increases (p<0.05) were observed in the numbers of Foxp3+ and CD8+ inflammatory cells, as well as in
IL-10 expression, in the well differentiated tumors, compared to the poorly differentiated tumors. No differences between the three different histological grades were observed in the numbers of CD19+ cells. The relationship between the tumor grade and Treg and CD8 cell recruitment in patients with OSCC underlined the fact that the immune system is deregulated as a consequence of the disease.