title: Potential role of regulatory T cells in reversing obesity-linked insulin resistance and diabetic nephropathy.
abstract: OBJECTIVE
  To assess the potential role of FoxP3-expressing regulatory T cells (Tregs) in reversing obesity-linked insulin resistance and diabetic nephropathy in rodent models and humans.
  
  
  METHODS
  To characterize the role of Tregs in insulin resistance, human visceral adipose tissue was first evaluated for Treg infiltration and second, the db/db mouse model was evaluated.
  
  
  RESULTS
  Obese patients with insulin resistance displayed significantly decreased natural Tregs but an increase in adaptive Tregs in their visceral adipose tissue as compared with lean control subjects. To further evaluate the pathogenic role of Tregs in insulin resistance, the db/db mouse model was used. Treg depletion using an anti-CD25 monoclonal antibody enhanced insulin resistance as shown by increased fasting blood glucose levels as well as an impaired insulin sensitivity. Moreover, Treg-depleted db/db mice developed increased signs of diabetic nephropathy, such as albuminuria and glomerular hyperfiltration. This was paralleled by a proinflammatory milieu in both murine visceral adipose tissue and the kidney. Conversely, adoptive transfer of CD4(+)FoxP3(+) Tregs significantly improved insulin sensitivity and diabetic nephropathy. Accordingly, there was increased mRNA expression of FoxP3 as well as less abundant proinflammatory CD8(+)CD69(+) T cells in visceral adipose tissue and kidneys of Treg-treated animals.
  
  
  CONCLUSIONS
  Data suggest a potential therapeutic value of Tregs to improve insulin resistance and end organ damage in type 2 diabetes by limiting the proinflammatory milieu.
authors.affiliation: Clinical Division of Nephrology, Department of Internal Medicine, Medical University Graz, Graz, Austria. kathrin.eller@medunigraz.at
authors.forename: Kathrin
authors.initials: K
authors.lastname: Eller
authors.forename: Alexander
authors.initials: A
authors.lastname: Kirsch
authors.forename: Anna M
authors.initials: AM
authors.lastname: Wolf
authors.forename: Sieghart
authors.initials: S
authors.lastname: Sopper
authors.forename: Andrea
authors.initials: A
authors.lastname: Tagwerker
authors.forename: Ursula
authors.initials: U
authors.lastname: Stanzl
authors.forename: Dominik
authors.initials: D
authors.lastname: Wolf
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Patsch
authors.forename: Alexander R
authors.initials: AR
authors.lastname: Rosenkranz
authors.forename: Philipp
authors.initials: P
authors.lastname: Eller
mesh_terms: D000818:Animals; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000276:immunology / Q000378:metabolism; D003928:Diabetic Nephropathies / Q000276:immunology* / Q000503:physiopathology / Q000517:prevention & control / Q000628:therapy*; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D051740:Ikaros Transcription Factor / Q000235:genetics / Q000378:metabolism; D007333:Insulin Resistance; D050152:Intra-Abdominal Fat / Q000378:metabolism / Q000473:pathology; D007668:Kidney / Q000378:metabolism / Q000473:pathology / Q000601:surgery; D008212:Lymphocyte Depletion / Q000009:adverse effects; D017710:Lymphocyte Transfusion; D008297:Male; D051379:Mice; D008820:Mice, Obese; D009765:Obesity / Q000276:immunology* / Q000378:metabolism / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism; D054411:Receptors, Leptin / Q000235:genetics; D013047:Specific Pathogen-Free Organisms; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism / Q000473:pathology
chemical_list: D016207:Cytokines; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; C111431:IKZF2 protein, human; D012333:RNA, Messenger; D054411:Receptors, Leptin; C515447:leptin receptor, mouse; D051740:Ikaros Transcription Factor