Inhibition of receptor-mediated calcium influx in T cells by unsaturated non-esterified fatty acids.
The effect of omega-3, omega-6 and omega-9 unsaturated fatty acids (UFAs) on receptor-mediated Ca2+ entry was investigated in a T-cell line (JURKAT) by using anti-CD3 antibodies (OKT3) to induce intracellular Ca2+ [( Ca2+]i) increase and Ca2+ influx. All the UFAs, as well as Ni2+ ions and 12-O-tetradecanoylphorbol 13-acetate, decreased the OKT3-induced sustained [Ca2+]i increase to basal levels. Although non-esterified fatty acids activate protein kinase C (PKC) [McPhail, Clayton & Snyderman (1984) Science 224, 622-624; Murakami, Chan & Routtenberg (1986) J. Biol. Chem. 261, 15424-15429], studies using H-7 and analysis of the PKC-dependent phosphorylation of 19 and 80 kDa marker substrates ruled out the involvement of PKC in UFA-induced inhibition of Ca2+ entry. Flow-cytometry analysis showed that UFAs do not interfere with antibody-receptor binding. BSA (0.2%, w/v) reversed the effect of UFAs after these fatty acids have decreased the OKT3-induced [Ca2+]i increase to basal levels. The relevance of these findings and possible mechanisms for inhibition by UFAs of receptor-mediated Ca2+ influx were discussed.
Chow
S C
SC
Department of Immunology, Karolinska Institute, Stockholm, Sweden.
Ansotegui
I J
IJ
Jondal
M
M
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology; D017252:CD3 Complex; D002118:Calcium / Q000378:metabolism*; D005230:Fatty Acids, Nonesterified / Q000494:pharmacology*; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D009532:Nickel / Q000494:pharmacology; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000502:physiology; D011948:Receptors, Antigen, T-Cell / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000945:Antigens, Differentiation, T-Lymphocyte; D017252:CD3 Complex; D005230:Fatty Acids, Nonesterified; D007546:Isoquinolines; D010879:Piperazines; D011948:Receptors, Antigen, T-Cell; D009532:Nickel; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium