title: Fish-oil-derived n-3 PUFAs reduce inflammatory and chemotactic adipokine-mediated cross-talk between co-cultured murine splenic CD8+ T cells and adipocytes.
abstract: BACKGROUND
  Obese adipose tissue (AT) inflammation is characterized by dysregulated adipokine production and immune cell accumulation. Cluster of differentiation (CD) 8+ T cell AT infiltration represents a critical step that precedes macrophage infiltration. n-3 (ω-3) Polyunsaturated fatty acids (PUFAs) exert anti-inflammatory effects in obese AT, thereby disrupting AT inflammatory paracrine signaling.
  
  
  OBJECTIVE
  We assessed the effect of n-3 PUFAs on paracrine interactions between adipocytes and primary CD8+ T cells co-cultured at the cellular ratio observed in obese AT.
  
  
  METHODS
  C57BL/6 mice were fed either a 3% menhaden fish-oil + 7% safflower oil (FO) diet (wt:wt) or an isocaloric 10% safflower oil (wt:wt) control (CON) for 3 wk, and splenic CD8+ T cells were isolated by positive selection (via magnetic microbeads) and co-cultured with 3T3-L1 adipocytes. Co-cultures were unstimulated (cells alone), T cell receptor stimulated, or lipopolysaccharide (LPS) stimulated for 24 h.
  
  
  RESULTS
  In LPS-stimulated co-cultures, FO reduced secreted protein concentrations of interleukin (IL)-6 (-42.6%), tumor necrosis factor α (-67%), macrophage inflammatory protein (MIP) 1α (-52%), MIP-1β (-62%), monocyte chemotactic protein (MCP) 1 (-23%), and MCP-3 (-19%) vs. CON, which coincided with a 74% reduction in macrophage chemotaxis toward secreted chemotaxins in LPS-stimulated FO-enriched co-culture-conditioned media. FO increased mRNA expression of the inflammatory signaling negative regulators monocyte chemoattractant 1-induced protein (Mcpip; +9.3-fold) and suppressor of cytokine signaling 3 (Socs3; +1.7-fold), whereas FO reduced activation of inflammatory transcription factors nuclear transcription factor κB (NF-κB) p65 and signal transducer and activator of transcription 3 (STAT3) by 27% and 33%, respectively. Finally, mRNA expression of the inflammasome components Caspase1 (-36.4%), Nod-like receptor family pyrin domain containing 3 (Nlrp3; -99%), and Il1b (-68.8%) were decreased by FO compared with CON (P ≤ 0.05).
  
  
  CONCLUSIONS
  FO exerted an anti-inflammatory and antichemotactic effect on the cross-talk between CD8+ T cells and adipocytes and has implications in mitigating macrophage-centered AT-driven components of the obese phenotype.
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and Guelph Food Research Centre, Agriculture Agri-Food Canada, Guelph, Canada.
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Monk
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and.
authors.forename: Danyelle M
authors.initials: DM
authors.lastname: Liddle
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and.
authors.forename: Anna A
authors.initials: AA
authors.lastname: De Boer
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and.
authors.forename: Morgan J
authors.initials: MJ
authors.lastname: Brown
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and Guelph Food Research Centre, Agriculture Agri-Food Canada, Guelph, Canada.
authors.forename: Krista A
authors.initials: KA
authors.lastname: Power
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and.
authors.forename: David Wl
authors.initials: DW
authors.lastname: Ma
authors.affiliation: Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, Canada; and lrobinso@uoguelph.ca.
authors.forename: Lindsay E
authors.initials: LE
authors.lastname: Robinson
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects; D054392:Adipokines / Q000378:metabolism*; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism; D054405:Chemokine CCL3 / Q000235:genetics / Q000378:metabolism; D054407:Chemokine CCL4 / Q000235:genetics / Q000378:metabolism; D054410:Chemokine CCL7 / Q000235:genetics / Q000378:metabolism; D015525:Fatty Acids, Omega-3 / Q000008:administration & dosage*; D005395:Fish Oils / Q000008:administration & dosage*; D015850:Interleukin-6 / Q000378:metabolism; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009765:Obesity / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D050796:STAT3 Transcription Factor / Q000235:genetics / Q000378:metabolism; D013154:Spleen / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism
chemical_list: D054392:Adipokines; C491768:Ccl2 protein, mouse; C496534:Ccl3 protein, mouse; C515451:Ccl7 protein, mouse; D018932:Chemokine CCL2; D054405:Chemokine CCL3; D054407:Chemokine CCL4; D054410:Chemokine CCL7; D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D015850:Interleukin-6; D012333:RNA, Messenger; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D051996:Transcription Factor RelA; C033266:Menhaden oil
keywords: CD8+ T cells; adipocytes; adipose tissue; chemokines; inflammatory cytokines; macrophage chemotaxis; mice; n–3 polyunsaturated fatty acids; obesity; paracrine cross-talk