Abstract: Objective To investigate the effect of IgG receptor FcγRIIB on systemic and adipose tissue inflammation and fat tissue lipid metabolism treated with high-fat diet (HFD). Methods We used 10 male mice with IgG receptor FcγRIIB knockout (FcγRIIB-/-) and another 10 male FcγRIIB+/+ mice as control, and treated them with HFD. At the end of the 17th week, mice were weighed, and the blood was taken by cardiac puncture after sacrifice. Adipose tissue was collected to measure inflammation and lipid metabolism. Results Compared with FcγRIIB+/+ mice, FcγRIIB-/- mice had significantly increased levels of inflammatory cytokines, IL-6, TNF-α, and IFN-γ in the serum, and increased macrophage infiltration in adipose tissue. M1 polarization gene MCP-1 and TNF-α increased (P<0.05) and M2 polarization gene ARG and IL-10 did not differ significantly. However, there was no significant difference in body mass, adipocyte size and lipid metabolism related genes PPARG, CEBPα, FASn, HSL, ATGL, UCP-1, GLUT4 expression. Conclusions Under HFD treatment, knocking out the IgG receptor FcγRIIB aggravates the inflammatory response of the whole body and adipose tissue, but cannot influence lipid metabolism of adipose tissue and body weight.

Key words: IgG, FcγRIIB, inflammation, adipose tissue, lipid metabolism