T cell up-regulation of CD127 is associated with reductions in the homeostatic set point of the peripheral T cell pool during malnourishment

• Published in: Biochemistry and biophysics reports Vol. 7; pp. 164 - 172
• Main Authors: Murphy, Sarah, Patrick, Kristin, Thoner, Timothy, Edwards, Regina W, Gubbels Bupp, Melanie R
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier 01.09.2016
• Subjects: Homeostasis; Malnutrition; T cells; Immunodeficiencies; Lymph nodes
• ISSN: 2405-5808; 2405-5808
• DOI: 10.1016/j.bbrep.2016.06.006

The following study was undertaken to better understand the mechanisms that relate the homeostatic set point of the peripheral T cell population to energy availability in mice. We report that the total number of peripheral naïve and memory CD4+ and CD8+T cells notably declined after one week of malnourishment, a time period too short to be entirely due to malnutrition-induced thymic involution. Peripheral malnourished T cells expressed higher levels of the IL-7 receptor component, CD127, and were less sensitive to death-by-neglect as compared to control T cells. Overall levels of IL-7 were similar in malnourished and control mice. Adoptive transfer studies revealed that CD127 expression did not correlate with increased survival and that all naïve CD8+T cells upregulated CD127, regardless of initial expression levels. Corticosterone levels were elevated in malnourished mice and this correlated in time with peripheral T cell up-regulation of CD127 and the diminishment of the peripheral T cell pool. Overall, these data suggest a model in which CD127 levels are up-regulated quickly during malnourishment, thereby increasing the scavenge rate of IL-7, and providing a mechanism to quickly adjust the total number of T cells during malnutrition.