Senescent T Cell Induces Brown Adipose Tissue Whitening Via Secreting IFN-γ

Aging-associated chronic inflammation is a key contributing factor to a cluster of chronic metabolic disorders, such as cardiovascular disease, obesity, and type 2 diabetes. Immune cells particularly T cells accumulate in adipose tissue with advancing age, and there exists a cross talk between T cell and preadipocyte, contributing to age-related adipose tissue remodeling. Here, we compared the difference in morphology and function of adipose tissue between young (3-month-old) and old (18-month-old) mice and showed the phenomenon of brown adipose tissue (BAT) whitening in old mice. Flow cytometry analysis suggested an increased proportion of T cells in BAT of old mice comparing with the young and exhibited senescent characteristics. We take advantage of coculture system to demonstrate directly that senescent T cells inhibited brown adipocyte differentiation of preadipocytes in adipose tissue. Mechanistically, both in vitro and in vivo studies suggested that senescent T cells produced and released a higher level of IFN-gamma, which plays a critical role in inhibition of preadipocyte-to-brown adipocyte differentiation. Taken together, the data indicate that senescent T cell-derived IFN-gamma is a key regulator in brown adipocyte differentiation.

Automated summary

Aging-associated chronic inflammation is a key factor contributing to chronic metabolic disorders. Research shows an accumulation of T cells in adipose tissue in old mice, with a cross talk between T cells and preadipocytes contributing to tissue remodeling. Senescent T cells were found to inhibit brown adipocyte differentiation in adipose tissue, with increased production of IFN-gamma identified as a critical mechanism.