Abstract
Natural killer (NK) cells are a population of lymphocytes which classically form part of the innate immune system. They are defined as innate lymphocytes, due to their ability to kill infected or transformed cells without prior activation. In addition to their cytotoxic abilities, NK cells are also rapid producers of inflammatory cytokines such as interferon gamma (IFN-γ) and are therefore a critical component of early immune responses. Due to these unique abilities, NK cells are a very important component of host protection, especially anti-tumour and anti-viral immunity. Obesity is a worldwide epidemic, with over 600 million adults and 124 million children now classified as obese. It is well established that individuals who are obese are at a higher risk of many acute and chronic conditions, including cancer and viral infections. Over the past 10 years, many studies have investigated the impact of obesity on NK cell biology, detailing systemic dysregulation of NK cell functions. More recently, several studies have investigated the role of NK cells in the homeostasis of adipose tissue and the pathophysiology of obesity. In this review, we will discuss in detail these studies and focus on emerging data detailing the metabolic mechanisms altering NK cells in obesity.
Highlights
Barra and colleagues showed that high intensity interval training (HIIT) increased Natural killer (NK) cell frequencies and function in obese women and mice, in addition to obesity, breast cancer cells where intravenously injected into the mice, and it was demonstrated that HIIT reduced tumour burden, with the authors postulating that this effect was mediated via increased NK cell activity (Figure 1) [73]
Mechanism which drives defective cells humanand obesity. It is well established our recent study, we show that NK cells isolated from obese patients dysregulated metabolism, cellInfunction is intrinsically dependent on cellular metabolism, with several studies highlighting the with a failure to engage glycolytic metabolism
We showed that culturing of NK cells with the free fatty (FFA), oleateoleate and palmitate, recapitulated obesity-like defects in NKincells, tumour lysis, acids (FFA), and palmitate, recapitulated obesity-like defects
Summary
Obesity is classically defined as an accumulation of excess adiposity. The current strategies for stratifying bodyweight are based on body mass index (BMI) which measures bodyweight in kilograms and divides by height in metres squared. This represents a 10-fold increase in childhood obesity since 1975 [2]. The estimated age-standardized prevalence of childhood obesity is 5% [3]. Large population studies have demonstrated that obesity increases the risk of developing numerous comorbidities, including type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD) and increased risk of many cancers [5,6]. These co-morbidities have been clearly shown to reduce the life expectancy of the obese individual
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
