Peripheral monocytes of obese women display increased chemokine receptor expression and migration capacity.

Context: The activation of peripheral immune cells and the infiltration of immune cells into adipose tissue in obesity are implicated in the development of type 2 diabetes mellitus. Objective: Aim of the study was to compare peripheral immune cells from obese and normal-weight women with regard to composition of immune cell subpopulations, surface expression of the chemokine receptors CCR2, CCR3, CCR5 and CXCR3 and cell-intrinsic migration capacity. Design: Case-Control Study. Setting: University Clinical Study Centre. Patients: Obese females and normal-weight females were included for fluorescence activated cell sorting (FACS) analysis and migration assays. Main Outcome Measures: Peripheral blood mononuclear cells (PBMCs) were prepared from fasting blood samples and used for FACS analysis and migration assays. Results: An increase in the percentages of CD14(+)CD16(+) monocytes was observed in obese subjects compared to controls. The chemokine receptor (CCR) profile of monocytes differed significantly in the obese state, particularly CCR2 levels were increased. In addition, a higher chemotactic activity of monocytes from obese subjects was observed in a migration assay, which was associated with both insulin resistance and CCR2 expression. Conclusion: Our results suggest that the enhanced intrinsic migratory capacity of peripheral monocytes in obese women may be due to the increased chemokine receptor expression, further supporting a link between peripheral immune cell dysfunction and obesity