Published online before print June 25, 2008
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Laboratory of Neuroendocrine-Immunology, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, USA
1 Correspondence: Laboratory of Neuroendocrine-Immunology, Pennington Biomedical Research Center, Louisiana State University System, 6400 Perkins Rd., Baton Rouge, LA 70808, USA. E-mail: Vishwa.dixit{at}pbrc.edu
ABSTRACT
Increasing evidence suggests a tight coupling of metabolic and immune systems. This cross-talk mediated by neuroendocrine peptides as well as numerous cytokines and chemokines is believed to be responsible for integrating energy balance to immune function. These neuroendocrine-immune interactions are heightened during the state of chronic positive energy balance, as seen during obesity, and negative energy balance caused by caloric restriction (CR). Emerging evidence suggests that obesity may be associated with an immunodeficient state and chronic inflammation, which contribute to an increased risk of premature death. The direct interactions between expanded leukocyte populations within the adipose tissue during obesity and an increased number of adipocytes within an aging lymphoid microenvironment may constitute an important adaptive or pathological response as a result of change in energy balance. In stark contrast to obesity, CR causes negative energy balance and robustly prolongs a healthy lifespan in all of the species studied to date. Therefore, the endogenous neuroendocrine-metabolic sensors elevated or suppressed as a result of changes in energy balance may offer an important mechanism in understanding the antiaging and potential immune-enhancing nature of CR. Ghrelin, one such sensor of negative energy balance, is reduced during obesity and increased by CR. Ghrelin also regulates immune function by reducing proinflammatory cytokines and promotes thymopoiesis during aging and thus, may be a new CR mimetic target. The identification of immune effects and molecular pathways used by such orexigenic metabolic factors could offer potentially novel approaches to enhance immunity and increase healthy lifespan.
Key Words: orexigenic • CR mimetic • anorexigenic • AMPK • NF-
B • mTOR • food intake • dietary • nutrition • immunity • ghrelin • GHS-R • inflammation • aging • leptin • IL-6 • thymus • bone marrow • TNF • macrophage • T cells
This article has been cited by other articles:
 |
|
 |
|
  J. M. Gimble and Z. E. Floyd Fat circadian biology J Appl Physiol, November 1, 2009; 107(5): 1629 - 1637. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Ahmed, S. K. Das, J. K. Golden, E. Saltzman, S. B. Roberts, and S. N. Meydani Calorie Restriction Enhances T-Cell-Mediated Immune Response in Adult Overweight Men and Women J Gerontol A Biol Sci Med Sci, November 1, 2009; 64A(11): 1107 - 1113. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. J. Chess, R. J. Khairallah, K. M. O'Shea, W. Xu, and W. C. Stanley A high-fat diet increases adiposity but maintains mitochondrial oxidative enzymes without affecting development of heart failure with pressure overload Am J Physiol Heart Circ Physiol, November 1, 2009; 297(5): H1585 - H1593. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Yang, Y.-H. Youm, B. Vandanmagsar, J. Rood, K. G. Kumar, A. A. Butler, and V. D. Dixit Obesity accelerates thymic aging Blood, October 29, 2009; 114(18): 3803 - 3812. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Yang, Y.-H. Youm, and V. D. Dixit Inhibition of Thymic Adipogenesis by Caloric Restriction Is Coupled with Reduction in Age-Related Thymic Involution J. Immunol., September 1, 2009; 183(5): 3040 - 3052. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Yang, Y.-H. Youm, Y. Sun, J.-S. Rim, C. J. Galban, B. Vandanmagsar, and V. D. Dixit Axin expression in thymic stromal cells contributes to an age-related increase in thymic adiposity and is associated with reduced thymopoiesis independently of ghrelin signaling J. Leukoc. Biol., June 1, 2009; 85(6): 928 - 938. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-H. Youm, H. Yang, Y. Sun, R. G. Smith, N. R. Manley, B. Vandanmagsar, and V. D. Dixit Deficient Ghrelin Receptor-mediated Signaling Compromises Thymic Stromal Cell Microenvironment by Accelerating Thymic Adiposity J. Biol. Chem., March 13, 2009; 284(11): 7068 - 7077. [Abstract] [Full Text] [PDF]
|
|
