Aging and immunity

The changes in the immune system with aging start at birth, not just after 50 years of age.As such, it is important to view the consequences of these changes over the lifespan.In addition to changes in antimicrobial protections, these changes also have a great influence on the aging of tissues, organs and functions of the human body and a person's immune-resilience is linked with longevity.Aging of the immune system is the topic of the reviews in this journal [1,2] and many other reviews and studies, some of which are listed herein.Many questions remain to be answered regarding the changes that occur over the course of a lifetime and their consequences.Some of these questions are raised in this editorial.Like a computer, some components of the immune system are hard wired and immediately functional, like the innate components, but other components must learn the programs and develop memory for the antigen-specific adaptive components.In the womb, maternal protections allow the system to develop with minimal need for surveillance or reactivity to challenge.Rapid growth and turnover of cells is tolerated.At birth, the immune system switches from innate and more regulatory actions to more active and reactive responses to take over from maternal protections.The system becomes trained/educated by microbial exposures.The timing and nature of the microbial training is a major determinant of the balance or predilection towards either Th2 helper responses that favor antibody, mucosal and eosinophilic responses or proinflammatory Th17 and Th1 responses that support antibody and epithelial, neutrophil, macrophage and other cell mediated protections.Ultimately, the goal is to develop a balance between the effector functions and the maintenance and regulatory functions without compromising protection from microbial attack or tumor surveillance.What influences do vaccination, diet, exercise and pre-birth health and activities play on the development of the fetal and child's immune system.What role does exposure to maternal microbiota upon traversing the birth canal or breast feeding have on the system?Can timing and microbial exposure be