Why We Lose Fat and Muscle During Infection; Salk Scientists Discover Role Immune System’s T Cells Play in Regulating Fat and Muscle Loss During Infection in Mice

Although infections can present with many different symptoms, one common symptom is the loss of fat and muscle, a process called wasting. Salk scientists wanted to determine whether wasting is beneficial in fighting infections. Researchers in Professor Janelle Ayres’ lab discovered the wasting response to T. brucei infection in mice occurs in two phases, each regulated by different immune cells. While fat loss did not benefit the fight against infection, muscle loss did—a surprising clue that some wasting may help manage illness. The findings, published in Cell Reports on July 24, 2023, can inform the development of more effective therapeutics that spare people from wasting and increase our understanding of how wasting influences survival and morbidity across infections, cancers, chronic illnesses, and more. The open-access article is titled “CD4+ T Cells Regulate Sickness-Induced Anorexia and Fat Wasting During a Chronic Parasitic Infection.”