Open AccessCC ‐chemokine receptor 7 ( CCR 7) deficiency alters adipose tissue leukocyte populations in mice
Author(s) -
Orr Jeb S.,
Kennedy Arion J.,
Hill Andrea A.,
AndersonBaucum Emily K.,
Hubler Merla J.,
Hasty Alyssa H.
Publication year - 2016
Publication title -
physiological reports
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 39
ISSN - 2051-817X
DOI - 10.14814/phy2.12971
Subject(s) - c c chemokine receptor type 7 , immune system , chemokine , adipose tissue , cd8 , endocrinology , medicine , biology , receptor , inflammation , immunology , chemokine receptor
The mechanism by which macrophages and other immune cells accumulate in adipose tissue ( AT ) has been an area of intense investigation over the past decade. Several different chemokines and their cognate receptors have been studied for their role as chemoattractants in promoting recruitment of immune cells to AT . However, it is also possible that chemoattractants known to promote clearance of immune cells from tissues to regional lymph nodes might be a critical component to overall AT immune homeostasis. In this study, we evaluated whether CCR 7 influences AT macrophage ( ATM ) or T‐cell ( ATT ) accumulation. CCR 7 −/− and littermate wild‐type ( WT ) mice were placed on low‐fat diet ( LFD ) or high‐fat diet ( HFD ) for 16 weeks. CCR 7 deficiency did not impact HFD ‐induced weight gain, hepatic steatosis, or glucose intolerance. Although lean CCR 7 −/− mice had an increased proportion of alternatively activated ATM s, there were no differences in ATM accumulation or polarization between HFD ‐fed CCR 7 −/− mice and their WT counterparts. However, CCR 7 deficiency did lead to the preferential accumulation of CD 8 + ATT cells, which was further exacerbated by HFD feeding. Finally, expression of inflammatory cytokines/chemokines, such as Tnf , Il6 , Il1β , Ccl2 , and Ccl3 , was equally elevated in AT by HFD feeding in CCR 7 −/− and WT mice, while Ifng and Il18 were elevated by HFD feeding in CCR 7 −/− but not in WT mice. Together, these data suggest that CCR 7 plays a role in CD 8 + ATT cell egress, but does not influence ATM accumulation or the metabolic impact of diet‐induced obesity.