Role of 5-lipoxygenase products of arachidonic acid in cell-to-cell interaction between macrophages and natural killer cells in rat spleen.
In the present study we performed experiments to reveal the role of 5-lipoxygenase products of arachidonic acid in cell-to-cell interaction between rat peritoneal macrophages and spleen natural killer (NK) cells. Peritoneal macrophages were found to significantly enhance NK cell activity. It was found that the enhancing activity of macrophages was significantly inhibited by the ingestion of highly purified eicosapentaenoic acid-ethyl ester (EPA-E). But direct cytotoxic action of macrophage on target cells (YAC-1) was unchanged by the ingestion of EPA-E. In addition, the depressed enhancing activity of EPA-enriched macrophages (EPA macrophages) was partially, but significantly, restored by the addition of either 10(-10) M leukotriene B4 (LTB4) or 10(-12) M 5-hydroperoxyeicosatetraenoic acid (5-HPETE). The partial restoring effect of 10(-10) M LTB4 was further significantly enhanced by the addition of 5-HPETE. In contrast 5-hydroxyeicosatetraenoic acid (5-HETE) had no modulatory effect on the depressed activity of EPA macrophages. LTB4, 5-HPETE, and 5-HETE had no direct effect on NK cell activity itself. Significantly less amounts of LTB4 and 5-HETE were produced in EPA macrophages as compared with that in control macrophages. The present study indicates that macrophage modulatory action on NK cells can be partly mediated by LTB4 and 5-HPETE, which are produced in macrophages.
Chang
K J
KJ
Second Department of Internal Medicine, Chiba University School of Medicine, Japan.
Saito
H
H
Tatsuno
I
I
Tamura
Y
Y
Yoshida
S
S
D000818:Animals; D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism* / Q000502:physiology; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism*; D002450:Cell Communication; D015118:Eicosapentaenoic Acid / Q000031:analogs & derivatives / Q000097:blood / Q000494:pharmacology; D007694:Killer Cells, Natural / Q000166:cytology*; D008264:Macrophages / Q000166:cytology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000166:cytology
D001095:Arachidonic Acids; D016718:Arachidonic Acid; C035276:eicosapentaenoic acid ethyl ester; D015118:Eicosapentaenoic Acid; D001094:Arachidonate 5-Lipoxygenase