Dietary Fish Oil Increases the Number of CD11b+CD27− NK Cells at the Inflammatory Site and Enhances Key Hallmarks of Resolution of Murine Antigen-Induced Peritonitis

Abstract

Purpose To determine the effects of dietary omega-3 polyunsaturated fatty acids (PUFAs) on recruitment of natural killer (NK) cells and resolution responses in antigen-induced peritonitis in mice. Methods Mice were fed fish oil-enriched or control diets, immunized twice and challenged intraperitoneally with methylated bovine serum albumin. Prior to and at different time-points following inflammation induction, expression of surface molecules on peritoneal cells was determined by flow cytometry, concentration of soluble mediators in peritoneal fluid by ELISA or Luminex, and of lipid mediators by LC-MS/MS, and number of apoptotic cells in mesenteric lymph nodes by TUNEL staining. Results Mice fed the fish oil diet had higher number of CD11b + CD27 − NK cells as well as a higher proportion of CD107a + NK cells in their peritoneum 6 h after inflammation induction than mice fed the control diet. They also had higher numbers of CCR5 + NK cells and higher concentrations of CCL5 and CXCL12. Additionally, a higher fraction of apoptotic neutrophils but lower fraction of CD47 + neutrophils were present in the peritoneum of mice fed the fish oil diet 6 h after inflammation induction and the fish oil fed mice had a shorter resolution interval. They also had lower concentrations of pro-inflammatory mediators but higher concentrations of the anti-inflammatory/pro-resolution mediators TGF-β, IGF-1, and soluble TNF RII, as well as higher ratios of hydroxyeicosapentaenoic acid (HEPE) to hydroxyeicosatetraenoic acid (HETE) than mice fed the control diet. Conclusion The results demonstrate that dietary fish oil increases the number of mature NK cells at the inflamed site in antigen-induced peritonitis and enhances several key hallmarks of resolution of inflammation, casting light on the potential mechanisms involved.

Omega‐3 fatty acid supplements and recurrent miscarriage: A perspective on potential mechanisms and clinical evidence

“…Accumulating evidence has shown that omega-3 fatty acids exert an immunoregulatory effect. One study showed that a fish oil-enriched diet (4.0 g EPA and 2.9 g DHA per kg diet) increased CD11B + CD27 − NK cells, CD107a + NK cells, and CCR5 + NK cells after inflammation induction in mice (Jensen et al, 2022). In cancers, the activity of NK cells is inhibited (Seliger & Koehl, 2022).…”

Human umbilical cord mesenchymal stem cell-derived treatment of severe pulmonary arterial hypertension

“…Samples were spiked with internal standards to a final concentration of 1.0 ng ml −1 and prepared using solid-phase extraction as described previously 47 , and 200 µl of CM samples was used. Medium samples were reconstituted in 200 µl of 40% MeOH and cell pellet samples in 100 µl of 40% MeOH.…”