Obesity increases the production of proinflammatory mediators from adipose tissue T cells and compromises TCR repertoire diversity: implications for systemic …

H Yang, YH Youm, B Vandanmagsar… - The Journal of …, 2010 - journals.aai.org
H Yang, YH Youm, B Vandanmagsar, A Ravussin, JM Gimble, F Greenway, JM Stephens
The Journal of Immunology, 2010journals.aai.org
Emerging evidence suggests that increases in activated T cell populations in adipose tissue
may contribute toward obesity-associated metabolic syndrome. The present study
investigates three unanswered questions: 1) Do adipose-resident T cells (ARTs) from lean
and obese mice have altered cytokine production in response to TCR ligation?; 2) Do the
extralymphoid ARTs possess a unique TCR repertoire compared with lymphoid-resident T
cells and whether obesity alters the TCR diversity in specific adipose depots?; and 3) Does …
Abstract
Emerging evidence suggests that increases in activated T cell populations in adipose tissue may contribute toward obesity-associated metabolic syndrome. The present study investigates three unanswered questions: 1) Do adipose-resident T cells (ARTs) from lean and obese mice have altered cytokine production in response to TCR ligation?; 2) Do the extralymphoid ARTs possess a unique TCR repertoire compared with lymphoid-resident T cells and whether obesity alters the TCR diversity in specific adipose depots?; and 3) Does short-term elimination of T cells in epididymal fat pad without disturbing the systemic T cell homeostasis regulate inflammation and insulin-action during obesity? We found that obesity reduced the frequency of naive ART cells in sc fat and increased the effector-memory populations in visceral fat. The ARTs from diet-induced obese (DIO) mice had a higher frequency of IFN-γ+, granzyme B+ cells, and upon TCR ligation, the ARTs from DIO mice produced increased levels of proinflammatory mediators. Importantly, compared with splenic T cells, ARTs exhibited markedly restricted TCR diversity, which was further compromised by obesity. Acute depletion of T cells from epididymal fat pads improved insulin action in young DIO mice but did not reverse obesity-associated feed forward cascade of chronic systemic inflammation and insulin resistance in middle-aged DIO mice. Collectively, these data establish that ARTs have a restricted TCR-Vβ repertoire, and T cells contribute toward the complex proinflammatory microenvironment of adipose tissue in obesity. Development of future long-term T cell depletion protocols specific to visceral fat may represent an additional strategy to manage obesity-associated comorbidities.
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