Adipose Tissue Immune Cells in Childhood-onset and Adult-onset Obesity Before and After Weight Loss

• Published in: Obesity (Silver Spring, Md.) Md.), 2022-11, Vol.30, p.58-58
• Main Authors: Murphy, Jessica, Tsoukas, Michael, Morais, Jose, Santosa, Sylvia
• Format: Article
• Language: English
• Subjects: Body fat; Childhood; Lymphocytes; Obesity; Weight control
• ISSN: 1930-7381; 1930-739X

Background: We do not understand why adults with sustained obesity from childhood have a higher risk of metabolic disease than those who develop obesity in adulthood. The adipose tissue inflammatory environment may play a role. We aimed to determine whether the age of obesity onset affects immune cells in abdominal (AB) and femoral (FEM) subcutaneous adipose tissue (SAT) before and after moderate (~10%) weight loss. Methods: We collected AB and FEM SAT from females (age=30.5±3.3 years; BMI=33.7±2.9 kg/m2) with childhood-onset (CO) and adult-onset (AO) obesity before (CO: n=14; AO: n=13) and after (CO: n=8; AO: n=6) diet- and exercise-induced weight loss. We used flow cytometry to quantify the proportion of immune cells in the stromovascular fraction of AB and FEM SAT. Results: Macrophage and T cell proportions in AB and FEM SAT were similar between groups at baseline. Across groups, AB had proportionately more CD68+CD206- M1-like macrophages and less T cells than FEM. Regardless of obesity onset, the proportion of CD68+CD206- M1-like macrophages declined with weight loss in the AB region only and was similar between AB and FEM post-weight loss. Across groups and regions, CD68+CD206+ M2-like macrophage and CD3+CD8+ T cell proportions did not change with weight loss. Across regions, the proportion of CD3+- CD4+ T cells increased with weight loss in AO but did not change in CO. Conclusions: Females with CO and AO have similar regional SAT immune cell profiles before but not after weight loss. Weight loss reduces the pro-inflammatory macrophage content of AB SAT regardless of obesity onset but increases AB and FEM CD3+CD4+ T cells in AO only. Since CD3+CD4+ T cells can be pro- or anti-inflammatory, further phenotyping of these cells is warranted. How our findings influence the disease risk discrepancy between CO and AO remains to be determined.