Human obesity reduces the number of hepatic leptin receptor (ob-R) expressing NK cells

Endocr Res. 2011;36(4):158-66. doi: 10.3109/07435800.2011.580442.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Cell Count
  • Humans
  • Immunohistochemistry
  • Killer Cells, Natural / metabolism*
  • Killer Cells, Natural / pathology
  • Liver / metabolism
  • Liver / pathology
  • Middle Aged
  • Obesity / metabolism*
  • Obesity / pathology*
  • Receptors, Leptin / biosynthesis*
  • Young Adult


  • Receptors, Leptin