Here is an example of the sort of work presently taking place in many of the labs interested in aging and longevity, consisting of exploration of existing drugs shown to have some effect on life span in animal studies, alongside continued research into the details of the calorie restriction response:
"Research has shown that consuming fewer calories, while maintaining sufficient nutrients, extends lifespan, and there are ongoing clinical studies in humans. However, aging also is associated with increased susceptibility to diseases. Remarkable extension of lifespan has been achieved in organisms by lowering calorie intake or tricking cells into thinking that there is not enough food. These manipulations are being considered for potentially increasing lifespan in humans. It is critical to understand the effects of these interventions upon physiological function of older organisms, as any increase in longevity must be accompanied by improved quality of life."
Rapamycin, or Rapa, a drug used to keep the body from rejecting organ and bone marrow transplants, blocks an enzyme that controls cellular division. Rapa has been shown to extend lifespan in mice; however, the effects of chronic low-dose Rapa-mediated treatment on resistance to infection remain unknown.
"Our study will test whether life-extending dietary interventions may improve or impair survival from, and immunity to, infection, allowing us to evaluate whether manipulations of nutrient pathways may be safe and desirable to achieve optimal healthy longevity. While calorie restriction appears to improve immune function and homeostasis in old animals, the few infectious challenge experiments suggest increased susceptibility to infection. Our exploratory proposal aims to test the hypothesis that calorie restriction and drugs that trick the cells into thinking that there is not enough food, such as Rapa, could be deleterious for protective immunity, because they may curtail full development of immune responses. We aim to dissect possible defects and discover whether we may use Rapa as is or whether we may need to seek for similar compounds with beneficial effects in healthy aging across different tissues."