Figure 7.

(a) Constitutive expression of interferon-γ (IFN-γ) by natural killer (NK) cells is increased in visceral adipose tissue (VAT) relative to subcutaneous adipose tissue (SAT). Representative dot-plots of SVF rested for 12 h in culture followed by intracellular staining for IFN-γ and surface staining for CD45, CD56 and CD3. (b) Depot-specific frequencies of constitutive IFN-γ expressing NK and T-cell subsets. Percent of total parent population (CD3+, CD3+CD4+ or CD3+CD8+ T cells or CD56+ NK cells) that constitutively expressed IFN-γ within VAT and SAT SVF. The percentage of CD56+ cells that constitutively expressed IFN-γ was increased in VAT compared to SAT. CD3+ cells demonstrated similar low levels of constitutive IFN-γ expression with no difference between depots. Values reported are percent of CD56+ or CD3+ populations positive for intracellular IFN-γ minus percent of populations (CD56+ or CD3+ populations) positive for intracellular isotype-matched control antibody. P-values were derived from paired t-test comparing VAT and SAT for each matched culture. Note that multiple points overlap at zero for NK cell SAT arm and T-cell VAT and SAT arms. A total of eight subjects were included for each arm of these experiments, as described in the Materials and methods section. Error bars: s.d.