title: Human obesity reduces the number of hepatic leptin receptor (ob-R) expressing NK cells.
abstract: OBJECTIVE
  In the industrialized world, obesity is an increasing socioeconomic health problem. Obese subjects have a higher risk of developing several types of cancer. NK cells are an integral component of the innate immune system, able to destruct tumor cells. The adipokine leptin plays a crucial role in the development of obesity and its related diseases. Peripheral leptin signaling is modulated by the liver.
  
  
  METHODS
  The aim of this study was to evaluate the number of hepatic NK cells (CD56+) and the number of leptin-receptor positive (Ob-R+) cells in the livers of five normal-weight and five obese humans. Livers were removed during autopsy and accurately defined sections were stained immunohistochemically and CD56+, Ob-R+, and double-positive cells were quantified.
  
  
  RESULTS
  Results revealed a dramatic reduction of NK cells and Ob-R-expressing NK cells in the livers of obese individuals.
  
  
  CONCLUSIONS
  The present study demonstrates, for the first time, body-weight-dependent numbers of hepatic NK cells. This supports the hypothesis of obesity-associated alterations of immune cell numbers in different human organs.
authors.affiliation: Institute for Functional and Applied Anatomy, Hanover Medical School, Hanover, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Lautenbach
authors.forename: Dirk
authors.initials: D
authors.lastname: Breitmeier
authors.forename: Susanne
authors.initials: S
authors.lastname: Kuhlmann
authors.forename: Heike
authors.initials: H
authors.lastname: Nave
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002452:Cell Count; D006801:Humans; D007150:Immunohistochemistry; D007694:Killer Cells, Natural / Q000378:metabolism* / Q000473:pathology; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008875:Middle Aged; D009765:Obesity / Q000378:metabolism* / Q000473:pathology*; D054411:Receptors, Leptin / Q000096:biosynthesis*; D055815:Young Adult
chemical_list: D054411:Receptors, Leptin