ABSTRACT
This chapter discusses the current literature on the impact of obesity on the immune system, both within the adipose tissue and systemically. It also discusses obesity's interactions with specific diseases, chiefly influenza. The chapter explores the relatively new idea that obesity may have an infectious origin. T-cells infiltrating the adipose tissue display activation markers, and regulatory T-cell populations increase within adipose tissue. In addition to their role as a storage site for lipids, adipocytes secrete a variety of factors, termed adipokines, including leptin and adiponectin. While the precise origin of obesity's immunological consequences remains open to debate, researchers believe that cells of the innate immune system mediate physiological changes present in obesity. Cells from the adaptive immune system play roles in both lean and obese conditions. Researchers believe obesity has numerous synergistic interactions with viral infections. Bacterial infections in the setting of obesity also alter in comparison with healthy weight.
