title: DHA-enriched fish oil targets B cell lipid microdomains and enhances ex vivo and in vivo B cell function.
abstract: DHA is a n-3 LCPUFA in fish oil that generally suppresses T lymphocyte function. However, the effect of fish oil on B cell function remains relatively understudied. Given the important role of B cells in gut immunity and increasing human fish oil supplementation, we sought to determine whether DFO leads to enhanced B cell activation in the SMAD-/- colitis-prone mouse model, similar to that observed with C57BL/6 mice. This study tested the hypothesis that DHA from fish oil is incorporated into the B cell membrane to alter lipid microdomain clustering and enhance B cell function. Purified, splenic B cells from DFO-fed mice displayed increased DHA levels and diminished GM1 microdomain clustering. DFO enhanced LPS-induced B cell secretion of IL-6 and TNF-α and increased CD40 expression ex vivo compared with CON. Despite increased MHCII expression in the unstimulated ex vivo B cells from DFO-fed mice, we observed no difference in ex vivo OVA-FITC uptake in B cells from DFO or CON mice. In vivo, DFO increased lymphoid tissue B cell populations and surface markers of activation compared with CON. Finally, we investigated whether these ex vivo and in vivo observations were consistent with systemic changes. Indeed, DFO-fed mice had significantly higher plasma IL-5, IL-13, and IL-9 (Th2-biasing cytokines) and cecal IgA compared with CON. These results support the hypothesis and an emerging concept that fish oil enhances B cell function in vivo.
authors.affiliation: Michigan State University, East Lansing, MI 48824-1224, USA. imigjeni@msu.edu
authors.forename: Eric A
authors.initials: EA
authors.lastname: Gurzell
authors.forename: Heather
authors.initials: H
authors.lastname: Teague
authors.forename: Mitchel
authors.initials: M
authors.lastname: Harris
authors.forename: Jonathan
authors.initials: J
authors.lastname: Clinthorne
authors.forename: Saame Raza
authors.initials: SR
authors.lastname: Shaikh
authors.forename: Jenifer I
authors.initials: JI
authors.lastname: Fenton
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects* / Q000276:immunology; D003092:Colitis / Q000178:diet therapy / Q000276:immunology / Q000378:metabolism / Q000473:pathology; D004041:Dietary Fats / Q000494:pharmacology*; D004195:Disease Models, Animal; D004281:Docosahexaenoic Acids / Q000494:pharmacology*; D005395:Fish Oils / Q000494:pharmacology*; D015870:Gene Expression; D006801:Humans; D018928:Immunity, Mucosal / Q000187:drug effects*; D018793:Interleukin-13 / Q000097:blood / Q000276:immunology; D015848:Interleukin-5 / Q000097:blood / Q000276:immunology; D015850:Interleukin-6 / Q000097:blood / Q000276:immunology; D016906:Interleukin-9 / Q000097:blood / Q000276:immunology; D007422:Intestines / Q000166:cytology / Q000187:drug effects / Q000276:immunology; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D018345:Mice, Knockout; D051785:Smad Proteins / Q000172:deficiency / Q000235:genetics; D058408:Th1-Th2 Balance / Q000187:drug effects; D014409:Tumor Necrosis Factor-alpha / Q000097:blood / Q000276:immunology
chemical_list: D004041:Dietary Fats; D005395:Fish Oils; D018793:Interleukin-13; D015848:Interleukin-5; D015850:Interleukin-6; D016906:Interleukin-9; D051785:Smad Proteins; D014409:Tumor Necrosis Factor-alpha; C577686:interleukin-6, mouse; D004281:Docosahexaenoic Acids