Epirubicin Inhibits sCD25 Secretion by Treg Cells from DLBCL Patients

Diffuse large B-cell lymphoma (DLBCL) is the most common type of malignant lymphoma (Fan et al., 2012). Chemotherapy remains the main treatment method for DLBCL. Most DLBCL patients can be alleviated after standard chemotherapy regimens, but about 25~30% of DLBCL patients may be resistant to the chemotherapy drug and belongs to the refractory DLBCL (Liu et al., 2013). Although many new chemotherapeutic agents and chemotherapy regimens for refractory DLBCL have been reported in recent years, the outcome is not good yet. CD4+CD25+ regulatory T (Treg) cells, characterized by coexpression of CD4 and CD25 markers, are recognized as a subpopulation of suppressor T cells that is able to suppress autoreactive T cells (Sakaguchi, 2000). In many patients with malignant diseases, such as ovarian, lung, breast, liver, gastric and esophageal cancers, the population of Treg cells are usually increased (Woo et al., 2001; Liyanage et al., 2002; Ichihara et al., 2003; Ormandy et al., 2005). Interestingly, there is also a tight correlation between Treg cells and DLBCL. Interleukin -2 (IL-2), an important cytokine in vivo, is able to induce T cell proliferation and activation after binding to it receptor,