title: In vivo test of the vertical phase separation hypothesis: the display of major histocompatibility complex (MHC) class I molecules on membranes of B cells from mice fed high-fat diets.
abstract: The membrane vertical phase separation hypothesis predicts that a decrease in plasma membrane acyl chain order will increase major histocompatibility complex (MHC) class I surface expression. The hypothesis is based on modification of plasma membrane acyl chain order in cell culture and has not been tested in vivo. In the present study, we isolated splenic B cells from C57/BL6 mice fed either a normal diet or high-fat diets enriched in SFA or MUFA and assayed for changes in plasma membrane acyl chain order and MHC class I surface expression. Plasma membranes of B cells from MUFA-fed mice had significantly decreased acyl chain order and increased headgroup order. The decrease in acyl chain order correlated with a significant increase in the acyl chain unsaturation of B cells from the MUFA-fed mice. MHC class I surface levels on B cells were not affected by the MUFA-rich diet. This study suggests that the membrane vertical phase separation hypothesis may have limited application in a physiologically relevant setting.
authors.affiliation: Department of Biology, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218, USA. saameshaikh@gmail.com
authors.forename: Saame Raza
authors.initials: SR
authors.lastname: Shaikh
authors.forename: Sarah
authors.initials: S
authors.lastname: Boyle
authors.forename: Jing
authors.initials: J
authors.lastname: Hua
authors.forename: Zhiping
authors.initials: Z
authors.lastname: Li
authors.forename: Michael
authors.initials: M
authors.lastname: Edidin
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002462:Cell Membrane / Q000276:immunology* / Q000378:metabolism; D002469:Cell Separation / Q000379:methods; D002849:Chromatography, Gas / Q000379:methods; D004041:Dietary Fats / Q000008:administration & dosage*; D005229:Fatty Acids, Monounsaturated / Q000008:administration & dosage*; D005434:Flow Cytometry / Q000379:methods; D015395:Histocompatibility Antigens Class I / Q000032:analysis* / Q000276:immunology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
chemical_list: D004041:Dietary Fats; D005229:Fatty Acids, Monounsaturated; D015395:Histocompatibility Antigens Class I