Immunometabolism and innate immunity in the context of immunological maturation and respiratory pathogens in young children.

Although children growing from birth into young adulthood undergo rapid physiological maturation, their immune systems are also undergoing significant changes that may affect how they respond to microbes and especially respiratory pathogens. A key component of control over microbes is the innate immune system that sustains pathogen suppression/elimination until the adaptive immune system can instigate clearance. Here, this review will summarize key characteristics of the developing innate immune system of neonates, infants, and toddlers. In addition, a brief summary of how immunometabolism affects the innate immune system, and its ramifications on the developing innate immune cells will also be covered. Given the key differences between innate immunity of young children and older children/adults and the generally higher levels of morbidity associated with respiratory viral infections of the former, not many studies have examined how metabolic or mitochondrial differences may be influencing their generally limited responses. Further studies in immunometabolism in the young could elucidate keys mechanisms causing the typical diminished responses observed in this population. ©2019 Society for Leukocyte Biology.