Social environment improves immune function and redox state in several organs from prematurely aging female mice and increases their lifespan.

Aging is associated with a chronic oxidative stress (increase of oxidants and decrease of antioxidants), which contributes to immunosenescence and therefore shorter longevity. Nevertheless, a positive social network has been related to the adequate maintenance of health and deceleration of aging. Adult prematurely aging mice (PAM) are characterized by their inadequate stress response to a T-maze, showing premature immunosenescence and oxidative stress establishment. These impairments contribute to shorter life spans in comparison to exceptional non-PAM (ENPAM). However, it is not known whether these characteristics of PAM could be prevented by a positive cohabitation. Therefore, the aim of the present work was to determine if the premature immunosenescence and oxidative stress shown by PAM could be avoided by the cohabitation with ENPAM, increasing their life span. Female CD1 PAM and ENPAM were divided into three experimental groups: PAM controls, ENPAM controls and a social environment experimental group, containing in the same cage ENPAM and PAM (proportion 5/2, respectively). After 2 months, mice were sacrificed and spleen, thymus, liver and heart removed. Later, several immune functions as well as oxidative stress parameters were assessed in spleen and thymus leukocytes. Also, several oxidative stress parameters were analyzed in liver and heart. The results showed that PAM, after co-housing with ENPAM, had improved immune functions and redox balance in spleen and thymus leukocytes. This improvement of redox state was also observed in liver and heart. Furthermore, all these positive effects seem to be related to the increased life span of PAM.