Medium-chain, Triglyceride-Containing Lipid Emulsions Increase Human Neutrophil beta2 Integrin Expression, Adhesion, and Degranulation

JPEN J Parenter Enteral Nutr. Jul-Aug 2000;24(4):228-33. doi: 10.1177/0148607100024004228.

Abstract

Background: To test the hypothesis that lipid emulsions with different triglyceride structures have distinct immunomodulatory properties, we analyzed human neutrophil adhesion and degranulation after lipid incubation.

Methods: Neutrophils, isolated from the blood of 10 healthy volunteers, were incubated in medium or physiologic (2.5 mmol/L) emulsions containing long-chain (LCT), medium-chain (MCT), mixed LCT/MCT, or structured (SL) triglycerides. Expression of adhesion molecules and degranulation markers was evaluated by flow cytometry. Also, functional adhesion was investigated by means of a flow cytometric assay using fluorescent beads coated with the integrin ligand intercellular adhesion molecule (ICAM)-1.

Results: Although LCT and SL had no effect, LCT/MCT significantly increased expression of the beta2 integrins lymphocyte-function-associated antigen 1 (+18%), macrophage antigen 1 (+387%), p150,95 (+82%), and (alphaDbeta2 (+230%). Degranulation marker expression for azurophilic (CD63, +210%) and specific granules (CD66b, +370%) also significantly increased, whereas L-selectin (CD62L, -70%) decreased. The effects of LCT/MCT were mimicked by the MCT emulsion. ICAM-1 adhesion (% beads bound) was increased by LCT/MCT (34% +/- 4%), whereas LCT (19% +/-3%) and SL (20% +/- 2%) had no effect compared with medium (17% +/- 3%).

Conclusions: LCT/MCT and MCT, contrary to LCT and SL emulsions, increased neutrophil beta2 integrin expression, adhesion, and degranulation. Apart from other emulsion constituents, triglyceride chain length might therefore be a key feature in the interaction of lipid emulsions and the phagocyte immune system.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • CD18 Antigens / metabolism
  • Cell Adhesion / physiology
  • Cell Degranulation / physiology
  • Fat Emulsions, Intravenous / administration & dosage
  • Fat Emulsions, Intravenous / pharmacology*
  • Female
  • Flow Cytometry
  • Humans
  • Intercellular Adhesion Molecule-1 / metabolism
  • Male
  • Middle Aged
  • Neutrophils / drug effects
  • Neutrophils / physiology*
  • Triglycerides / administration & dosage*
  • Triglycerides / pharmacology

Substances

  • CD18 Antigens
  • Fat Emulsions, Intravenous
  • Triglycerides
  • Intercellular Adhesion Molecule-1