Aim: 

The age-related impairment of the immune function, known as immunosenescence, involves both innate and adaptive immune responses. Most of these changes are associated with T cell activities, such as the lymphoproliferative and the Natural Killer activity, which have been proposed as good markers of biological age and predictors of longevity. Moreover, it is well known that obesity is linked to an impaired immune function in both humans and rodents.

In the present work, the above mentioned immune functions have been studied in a murine model of genetic obesity (Zucker rats) with respect to Wistar rats of the same chronological age.

Methods: 

Male rats of two different strains (Zucker and Wistar) were used. Zucker rats are known as "Fa/Fa" (which carry the homozygotic mutation of the leptin receptor gene) and "Lean" (wich carry the heterozygotic mutation). Both groups of Zucker rats and a group of Wistar rats of the same chronological age were sacrified at six months of age and spleen and thymus leucocytes were obtained. The lymphoproliferative response to three different mitogens (Concanavaline A, Lypopolysaccharide and Phytohemaglutinine) and the Natural Killer activity (lysis of a murine lymphoma cell line) were evaluated.

Results: 

The lymphoproliferation and Natural Killer activities were decreased in leukocytes of Zucker rats with respect to Wistar.

Conclusions: 

Obese Zucker rats display an immunosenescence status with respect to Wistar rats of the same chronological age, which could indicate that these animals exhibit an older biological age and, consequently, suffer premature aging.

Support: MEC (DEP2006-56187-CO-02/PREV), Research Group UCM (910379ENEROINN) and RETICEF (RD06/0013/0003).