Patients with oral squamous cell carcinoma are characterized by increased frequency of suppressive regulatory T cells in the blood and tumor microenvironment

T-helper and T-regulatory cells modulation in head and neck squamous cell carcinoma

“…43 Moreover, activated CD4 C CD25 C Foxp3 C T cells in peripheral blood of HNSCC patients are significantly more effective in inhibiting effector T cells than those from healthy controls. 51 Therefore, it is conceivable that cancerreleased cytokines might affect Treg cells development outside the tumor tissue, although at a lesser degree than in tumor stroma.…”

“…A significant increase of IL-10 and TGFb levels has been reported in tumor, probably promoted by Tregs since Treg isolated from OSCC significantly induced IL-10 and TGFb release from co-cultured allogenic PBMC. 51 Nevertheless, Strauss and colleagues demonstrated that, at least for circulating Treg, immune suppression is mainly due to direct cell-to-cell interaction. In fact, co-incubation of peripheral blood isolated Treg with autologous T cells separated by permeable transwell insert resulted in no suppression, thus indicating that soluble factors diffusion is not enough to mediate immune suppression and that it rather relies on direct cellto-cell contact.…”

Levels of peripheral CD4+FoxP3+ regulatory T cells are negatively associated with clinical response to adoptive immunotherapy of human cancer

“…22 However, the role of CD4 ϩ Tregs in restraining immune responses directed against tumor antigens is unclear. Relatively high frequencies of infiltrating CD4 ϩ Tregs have been observed in solid cancers such as metastatic melanoma and oral squamous cell carcinomas, 23,24 and modestly increased frequencies of CD4 ϩ Tregs have also been observed in the peripheral blood of cancer patients. 23,25,26 The presence of relatively high levels of CD4 ϩ Tregs infiltrating ovarian cancer specimens was associated with poor prognosis in these patients 26,27 ; however, a similar study carried out in patients with colorectal carcinoma indicated that a high intratumoral density of CD4 ϩ FoxP3 ϩ T cells was associated with enhanced survival.…”

Immunological Processes in Cancer: A Link Between Inflammation and Immunity

“…The role for Tregs in oral squamous cell carcinoma was reported by Gasparoto et al (2010). The authors showed the presence of Tregs in oral squamous cell car-cinoma lesions and in the peripheral blood mononuclear cell from patients, where Tregs seem to act as suppressor of immune system response.…”