title: Diet-induced obesity in mice reduces the maintenance of influenza-specific CD8+ memory T cells.
abstract: Obesity has been associated with increasing the risk for type 2 diabetes and heart disease, but its influence on the immune response to viral infection is understudied. Memory T cells generated during a primary influenza infection are important for protection against subsequent influenza exposures. Previously, we have demonstrated that diet-induced obese (DIO) mice have increased morbidity and mortality following secondary influenza infection compared with lean mice. To determine whether the problem resided in a failure to maintain functional, influenza-specific CD8(+) memory T cells, male DIO and lean mice were infected with influenza X-31. At 84 d postinfection, DIO mice had a 10% reduction in memory T cell numbers. This reduction may have resulted from significantly reduced memory T cell expression of interleukin 2 receptor beta (IL-2R beta, CD122), but not IL-7 receptor alpha (CD127), which are both required for memory cell maintenance. Peripheral leptin resistance in the DIO mice may be a contributing factor to the impairment. Indeed, leptin receptor mRNA expression was significantly reduced in the lungs of obese mice, whereas suppressor of cytokine signaling (Socs)1 and Socs3 mRNA expression were increased. It is imperative to understand how the obese state alters memory T cells, because impairment in maintenance of functional memory responses has important implications for vaccine efficacy in an obese population.
authors.affiliation: Department of Nutrition, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599-7461, USA.
authors.forename: Erik A
authors.initials: EA
authors.lastname: Karlsson
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Sheridan
authors.forename: Melinda A
authors.initials: MA
authors.lastname: Beck
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000502:physiology*; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D004040:Dietary Carbohydrates / Q000009:adverse effects*; D004041:Dietary Fats / Q000009:adverse effects*; D005786:Gene Expression Regulation / Q000276:immunology; D008168:Lung / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000139:chemically induced*; D009975:Orthomyxoviridae / Q000276:immunology*; D009976:Orthomyxoviridae Infections / Q000276:immunology* / Q000473:pathology / Q000821:virology; D054411:Receptors, Leptin / Q000235:genetics / Q000378:metabolism; D050826:Suppressor of Cytokine Signaling Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D016207:Cytokines; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D054411:Receptors, Leptin; D050826:Suppressor of Cytokine Signaling Proteins