Effects of conjugated linoleic acid on growth and cytokine expression in Jurkat T cells.
Conjugated linoleic acid (CLA) has shown beneficial properties in animal models including anti-cancer, anti-atherogenic and anti-diabetic effects, while contrasting immunological effects were reported. While its anti-inflammatory activity has been associated to inhibition of arachidonic acid biosynthesis and to peroxisome proliferator-activated receptors (PPARs) activity, the molecular pathways underlying its immunoenhancing activity are essentially unknown. The aim of our study was to examine whether CLA showed specific effects in vitro on a T cell model, represented by the Jurkat cell line. CLA was found non toxic for Jurkat in the range 50-200 microM, as assessed by LDH release; however, incubation with 50 microM CLA was associated to a significant inhibitory effect on cell proliferation. The analysis of IL-2 and IFN-gamma transcript levels, produced in stimulated Jurkat cells, showed an increased expression of both cytokines in CLA-treated cells. Interestingly, the increased induction of IL-2 but not of IFN-gamma mRNA, could be suppressed by co-incubation with Gö 6976, a protein kinase C (PKC) inhibitor. Co-incubation with superoxide dismutase (SOD) or N-acetyl-L-cysteine (NAC) restored the basal levels of RNA synthesis for both cytokines. Taken together, these results suggest a specific role for dietary CLA in the modulation of the immune response in a T cell line model that is mediated, at least in part, by PKC and through the production of oxidative molecules.
Luongo
Diomira
D
Istituto di Scienze dell'Alimentazione, CNR, via Roma 52, 83100 Avellino, Italy.
Bergamo
Paolo
P
Rossi
Mauro
M
D000975:Antioxidants / Q000378:metabolism / Q000494:pharmacology; D016923:Cell Death / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D016207:Cytokines / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007371:Interferon-gamma / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D019169:Jurkat Cells; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D044243:Linoleic Acids, Conjugated / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D008934:Mitogens / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects
D000975:Antioxidants; D016207:Cytokines; D007376:Interleukin-2; D044243:Linoleic Acids, Conjugated; D008934:Mitogens; D012333:RNA, Messenger; D007371:Interferon-gamma; D007770:L-Lactate Dehydrogenase; D011493:Protein Kinase C