Parenteral lipids modulate leukocyte phenotypes in whole blood, depending on their fatty acid composition.
To characterize the immunological effects of various lipids that are applied as part of total parenteral nutrition (TPN) formulations, we analyzed phenotypical changes in leukocytes following lipid exposure. Importantly, the study was performed with whole blood in order to prevent the functional changes that are induced by isolation procedures. Briefly, blood samples from 10 healthy volunteers were incubated with lipids containing pure long-chain triglycerides (L), mixed long- and medium-chain triglycerides (LM), synthetic structured lipids (SL), or emulsions based on olive oil (OO), or fish oil (FO). After immune fluorescent staining, leukocyte phenotype characteristics were analyzed by flowcytometry. Exposure to LM increased in a dose-dependent manner the expression of membrane surface markers for adhesion (CD11b) and degranulation (CD66b), while decreasing CD62L, on neutrophils and monocytes. These findings demonstrate that LM activates leukocytes in peripheral whole blood. On the other hand, decreased expression of activation markers was observed with L and FO. Lipids effects on the phenotype of T lymphocytes and Natural Killer cells were not seen during incubation for up to 4 h. These results indicate that (i) the composition of TPN formulations with regard to lipid structure has implications for the function of exposed immune competent cells and (ii) medium-chain triglycerides, which have been regarded as functionally inert deliverers of fuel calories, have distinct biological effects.
Versleijen
Michelle
M
Department of Gastroenterology, Radboud University Nijmegen Medical Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
Roelofs
Hennie
H
Preijers
Frank
F
Roos
Dirk
D
Wanten
Geert
G
D000328:Adult; D015703:Antigens, CD / Q000378:metabolism*; D018845:CD11 Antigens / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology; D015550:Cell Degranulation / Q000502:physiology; D004306:Dose-Response Relationship, Immunologic; D005217:Fat Emulsions, Intravenous / Q000737:chemistry* / Q000494:pharmacology*; D005227:Fatty Acids / Q000737:chemistry / Q000276:immunology* / Q000494:pharmacology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D019041:L-Selectin / Q000378:metabolism; D007962:Leukocytes / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010289:Parenteral Nutrition, Total / Q000379:methods*; D010641:Phenotype; D014280:Triglycerides / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology
D015703:Antigens, CD; D018845:CD11 Antigens; D005217:Fat Emulsions, Intravenous; D005227:Fatty Acids; D014280:Triglycerides; D019041:L-Selectin