Characterization of bilirubin transport system by human peripheral blood mononuclear cells

Y. Haga, M. A. Tempero, H. D. Kay, R. K. Zetterman

Research output: Contribution to journalArticle

5 Scopus citations

Abstract

Decreased immune responses have been observed in hyperbilirubinemic patients. This study investigates bilirubin transport into human peripheral blood mononuclear cells (PBMNCs). In vitro incubation of PBMNCs at 37°C with 0-12 mg/dl bilirubin in solution with a fixed bovine serum albumin (BSA) concentration (3.0 g/dl) resulted in a dose-dependent increase of intracellular bilirubin in both monocytes and lymphocytes. Bilirubin uptake in monocytes was significantly higher (up to 2.7 times) than in lymphocytes under the same culture conditions. When PBMNCs were incubated with varying concentrations of bilirubin (0-16 mg/dl) in flxed BSA (3.0 g/dl) solution or at a fixed bilirubin/albumin molar ratio (0.4), the initial velocity of uptake in both cell fractions was proportional to the free (unbound to albumin) bilirubin concentration rather than the total bilirubin concentration. Bilirubin uptake by both cell fractions was significantly inhibited by treatment with metabolic inhibitors. Bilirubin uptake by monocytes continued to increase in parallel with incubation temperature from 0°C to 40°C, whereas uptake by lymphocytes reached a maximal level at 20°C and remained constant thereafter. These results suggest that monocytes and lymphocytes incorporate bilirubin in proportion to the free bilirubin concentration and this function may rely on different energy-dependent mechanisms.

Original languageEnglish (US)
Pages (from-to)2-6
Number of pages5
JournalJournal of Leukocyte Biology
Volume51
Issue number1
DOIs
StatePublished - 1992

Keywords

  • bilirubin
  • jaundice
  • liver disease
  • lymphocytes
  • monocytes

ASJC Scopus subject areas

  • Immunology and Allergy
  • Immunology
  • Cell Biology

Fingerprint Dive into the research topics of 'Characterization of bilirubin transport system by human peripheral blood mononuclear cells'. Together they form a unique fingerprint.

  • Cite this