ABSTRACTS: Oral Presentation Abstracts
Introduction: Polyunsaturated fatty acids (PUFA’s) have been shown to be important for regulation of the level of pro or anti-inflammatory immune responses induced by LPS and other stimuli. The study was undertaken to find out if two intravenous emulsions: olive oil-based Clin Oleic 20% (Baxter Clintec) with 20% of polunsaturated fatty acids (PUFA’s) and soybean oil-based Intralipid 20% (Fresenius Kabl) with 60% of PUFA’s will differ in their abilities for induction of monocyte surface receptors expression and cytokines synthesis in non-stimulated or LPS-induced PBMC.
Methods: PBMC of healthy blood donors (n=6) (2x106/ml) were incubated for 24 hrs in the culture medium only (control), or in the presence of: a) Clin-Oleic or Intralipid (0.1%-0.005%), b) LPS (50–6 ug/ml), c) LPS (12 ug/ml) plus Clin-Oleic or Intralipid (0.1%-0.005%) The level of cytokines (IL-10, IFN-gamma, TNF-alfa and IL-6) was estimated by ELISA. The expression of CD54, CD80, CD86, HLA-DR, LFA-1, CD32 and CD25 surface receptors (in terms of % and fluoresence intensity-FI) was assessed by double color flow cytometry (EPICS-XL MCL) in the cell population gated as monocytes.
Results: 1) neither Clin Oleic nor Intralipid induced PBMC for cytokines synthesis above the level of the control values, 2) LPS-induced cytokines synthesis was not significantly changed by both Clin-Oleic and Intralipid being for: a) IL-10 (814± 88 vs. 762±126 and 738±137 pg/ml), b) IFN-g (515±24 vs. 485±32 and 488±26 pg/ml), c) TNF-a (1057±88 vs. 1003±250 and 1013±284 pg/ml) and d) IL-6 (257±28 vs. 197±71 and 254±24 pg/ml), respectively, 3) only the expression of CD54 (in terms of FI) had tendency to be decreased by Clin-Oleic and Intralipid both in PBMC cultures (29.14±14.3 and 32.9±17.1 vs. 38.9±19.1 of the control) and LPS-induced PBMC (83.5±18.4 and 82.9±13.1 vs. 94.5±14.1 of the control, respectively), 4) Clin-Oleic and Intralipid slightly increased (in terms of FI) the expression of HLA-DR on monocytes in unstimulated PBMC (44.6±12.1 and 46.2±18.3 vs. 33.4±16.0 of control, respectively) but not in LPS-induced PBMC, 5) the expression of other monocyte surface receptors tested was not influenced by Clin-Oleic or Intralipid regardless of the cells stimulation with LPS or not.
Conclusion: Clin-Oleic and Intralipid intravenous emulsions did not simulate, inhibit or costimulate PBMC population in vitro in terms of: a) modulation of the expression of monocyte surface receptors, b) anti inflammatory (IL-10) and pro-inflammatory (IFN-g, TNF-a, IL-6) cytokines synthesis.