Understanding age-associated defects in T cell immunity

Abstract

The ability of the immune system to protect against antigenic challenges declines with increasing age, leading to increased susceptibility to newly arising infections such as with SARS-CoV-2 in old individuals. While vaccination ise of the most successful and safest interventions in modern medicine, vaccination programs have been less beneficial and provided incomplete protection particularly in older populations. Those poor immune responses in the aged population attribute to impaired adaptive immunity with the significant alterations in both quantity and quality of the T cell compartment. Studies have identified multiple changes in T cell immunity that contribute to age-related defects, including T cell priming, differentiation, generation of effector and memory T cells, epigenetic regulation, and metabolic function. In this lecture, I will overview the mechanisms that cause those alterations in T cell immunity in older individuals. Understanding those mechanistic insights may provide a framework for improved design of age-specific vaccination strategies as well as interventions to prevent or reverse age-related T cell failure.