Profile of immune cells in lymph nodes draining human malignant tumors

The purpose of this study was to characterize and quantify cells involved in immune response in metastasis-free regional lymph nodes (RLNs) draining different human epithelial tumors and compare them (by immunohistochemistry) with control lymph nodes from patients with non malignant diseases. We showed that T cells number was decreased in RLNs as compared to the controls with reduction in both CD4+ T cells and CD8+ T cells subsets and an inverted ratio (CD4+: CD8+). B lymphocytes and follicular dendritic cells were decreased with respect to the controls. S100+ dendritic cells (DCs) and mature DCs were detected in T dependent areas. Their mean number was significantly lower as compared to control. Immature DCs were significantly diminished compared to RLN and control nodes. CD57+ cells, follicular T helper cells and/or NK cells, were localized in the clear zone of germinal centres and their mean number was significantly increased. There were no CD57+ cells in hypoplastic follicles. In this study we show that RLNs draining human cancer present reduction in almost all immune cells, except CD57+ cells. These findings may be related to the deficient anti-tumor immune response in patients with cancer and subsequent tumor progression.