A high rate of metabolism suppresses an immune response during carcinogenesis

Energy turnover, expressed as a measure of basal metabolic rate (BMR), can serve as an informative marker of general health status and a predictor of cancer development via multiple physiological pathways, including the immune response. As mounting defensive mechanisms remains an energy-demanding process, any impairment in energy expenditure may play a crucial role in an organism's ability to protect against malignant transformation. Here, we tested the contribution of variation in basal metabolic rate to the intensity of both immune responses (as reflected in changes in the number of T subsets and pro-inflammatory cytokine levels) and leucocyte apoptosis during carcinogenesis, using lines of mice divergently selected for high or low BMR. Individuals from the high BMR line type showed a lower number of CD4 + and CD8 + T lymphocytes, accompanied by a higher rate of apoptosis among overall immunocompetent cells during cancer development. Moreover, we observed increased concentrations of pro-inflammatory cytokines IL-6 and IL-17A in those animals, which are potential biomarkers for predicting malignancy transformation. It may suggest that the energy budget of the low BMR mice is less strained, allowing them to mount an enhanced immune response and more efficient protection against cancer.