High interleukin-12 production from stimulated peripheral blood mononuclear cells of type 2 diabetes patients

Sugar control is important in patients with sepsis. Interleukin (IL)-12 induces the polarization of CD4⁺ T cells to the T helper 1 (Th1) phenotype. Regulatory T (T_reg) cells are important in immunity and disease. The aim of this work is to determine whether hyperglycemia or insulin alters IL-12 response in peripheral mononuclear cells (PBMCs). Methods: The PBMCs from 15 type 2 diabetes mellitus (DM) patients and 13 healthy controls were used for cell analysis and culture with or without treatment by glucose and insulin or stimulation by lipopolysaccharide (LPS) for 1, 2, and 3. days. Results: The IL-12 level in the supernatant of LPS-stimulated PBMCs in the DM patients was significantly higher than that of healthy controls from day 1 to day 3. Kinetic IL-12 responses of LPS-stimulated PBMCs in the DM patients from day 1 to day 3 were significantly higher than that in healthy controls. The LPS-stimulated PBMCs under glucose treatment produced more IL-12 in DM patients but this did not happen in healthy controls. In DM patients, insulin could suppress IL-12 production from stimulated PBMCs but not with additional glucose treatment. Conclusion: The PBMCs of LPS-treated DM patients produced more IL-12 than that of LPS-treated healthy controls did. Hyperglycemia influenced IL-12 response from PBMCs in DM patients to some degree during infection.