Adipose tissue immune cells in obesity, type 2 diabetes mellitus and cardiovascular diseases

Immune cells are an inseparable component of adipose tissue intimately involved in most of its functions. Physiologically, they regulate adipose tissue homeostasis, while in case of adipose tissue stress, immune cells are able to change their phenotype, enhance their count and subsequently contribute to the development and maintenance of local adipose tissue inflammation. Immune cells are an important source of inflammatory cytokines and other pro-inflammatory products that further influence not only surrounding tissues but via systemic circulation also the whole organism being thus one of the main factors responsible for the transition from simple obesity to associated metabolic and cardiovascular complications. The purpose of this review is to summarize current knowledge on different adipose tissue immune cell subsets and their role in the development of obesity, type 2 diabetes mellitus and cardiovascular diseases.