Intracellular Levels of IL-10 and STAT3 in Patients with Chronic Lymphocytic Leukemia

Objective: Chronic Lymphocytic Leukemia (CLL) is characterized by the accumulation of CD5+CD19+ B cells in the bone marrow and peripheral blood. Recent studies indicated that expression of IL-10, AID and mir-155 which are regulated by STAT3 are increased in CLL patients. CD5+CD19+ regulator B (Breg) cells secrete IL-10 and suppress the immune system. While the CLL cells show similar immunophenotypic properties to Breg cells, they are also thought to be functionally similar. In this study, STAT3 and IL-10 levels of CLL patients were investigated.Methods: Peripheral blood samples obtained from patients (n:24) and healthy controls (n:14). Peripheral blood mononuclear cells were cultured for 48 hours in the presence and absence of CpG for IL-10 expression and cultured with and without PMA for STAT3 expression. IL -10 and STAT3 expression were analyzed with anti-CD5, anti-CD19, anti-CD38, anti-STAT3 and anti-IL-10 monoclonal antibodies by using flow cytometry.Results: Compared to healthy subjects, increased IL-10+, IL-10+CD19+, STAT3+CD19+ were obtained in lymphocyte population of patients. Increased IL-10 was showed CD19+ B cells of CLL patients. Our results showed that IL-10 levels had no significant difference between CD5+CD19+ cells, whereas STAT3 levels were found lower in patient compared to healthy controls.Conclusion: These results made us thought that the levels of IL-10 and STAT3 expression in CLL B cells is clearly different from normal B lymphocytes might have a role in the biology of CLL. It is believed that the presented data will contribute to the studies that scrutinize the similarity of CLL cells to Breg cells.

Automated summary

In this study, STAT3 and IL-10 levels were investigated in CLL patients. The results showed increased IL-10+CD19+, IL-10+ and STAT3+CD19+ in lymphocytes of patients compared to healthy subjects. The expression of IL-10 was found to be increased in CD19+ B cells of CLL patients, while the expression of STAT3 was lower in patients compared to healthy controls. These findings suggest that the levels of IL-10 and STAT3 expression in CLL B cells differ from normal B lymphocytes and may play a role in the biology of CLL.