Leukotriene B(4) receptors BLT1 and BLT2 are involved in interleukin-8 production in human neutrophils induced by Trichomonas vaginalis-derived secretory products.
OBJECTIVE
Trichomonas vaginalis is a flagellated protozoan parasite that causes human trichomoniasis. Although T. vaginalis itself can secrete lipid mediator leukotriene (LT) B(4) leading to neutrophil activation, information regarding the signaling mechanism involved in neutrophil activation induced by T. vaginalis-secreted LTB(4) is limited. We investigated whether LTB(4) contained in the T. vaginalis-derived secretory products (TvSP) is closely involved in interleukin (IL)-8 production in human neutrophils via LTB(4) receptors BLT1 or BLT2.


RESULTS
T. vaginalis produced more than 714 pg/ml of LTB(4) per 1 × 10(7) trichomonads. The ability of trichomonads to secrete LTB(4) was inhibited by treatment of trichomonads with the 5-lipo-oxygenease inhibitor AA861, but not the cyclo-oxygenease I inhibitor FR122047. When neutrophils were incubated with TvSP obtained from 1 × 10(7) trichomonads, IL-8 protein secretion was significantly increased compared to results for cells incubated with medium alone. The stimulatory effect of TvSP on IL-8 production was strongly inhibited by pretreatment of TvSP with lipase, although pretreatment with heat or proteinase K showed little inhibitory effect. Moreover, TvSP-induced IL-8 production was efficiently inhibited when trichomonads were pretreated with AA861 or when neutrophils were pretreated with antagonists for BLT1 or BLT2.


CONCLUSIONS
Our results suggest that LTB(4) receptors BLT1 and BLT2 are involved in IL-8 production in neutrophils induced by T. vaginalis.
Department of Environmental Medical Biology and Institute of Tropical Medicine, Yonsei University College of Medicine, 134 Sichon-dong, Seodaemun-gu, Seoul, 120-752, Korea.
Young Hee
YH
Nam
Arim
A
Min
Seong Hoon
SH
Kim
Young Ah
YA
Lee
Kyeong Ah
KA
Kim
Kyoung-Ju
KJ
Song
Myeong Heon
MH
Shin
D016227:Benzoquinones / Q000494:pharmacology; D019286:Endopeptidase K / Q000494:pharmacology; D005233:Fatty Alcohols / Q000494:pharmacology; D006018:Glycols / Q000494:pharmacology; D006358:Hot Temperature; D006801:Humans; D016209:Interleukin-8 / Q000096:biosynthesis / Q000276:immunology* / Q000378:metabolism; D020024:Leukotriene Antagonists / Q000494:pharmacology; D007975:Leukotriene B4 / Q000032:analysis; D008049:Lipase / Q000494:pharmacology; D016859:Lipoxygenase Inhibitors / Q000494:pharmacology; D018375:Neutrophil Activation / Q000187:drug effects / Q000276:immunology; D009504:Neutrophils / Q000187:drug effects / Q000276:immunology* / Q000469:parasitology; D010879:Piperazines / Q000494:pharmacology; D018102:Receptors, Leukotriene B4 / Q000037:antagonists & inhibitors / Q000276:immunology*; D013777:Tetrazoles / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014245:Trichomonas Infections / Q000276:immunology* / Q000469:parasitology; D014246:Trichomonas vaginalis / Q000187:drug effects / Q000276:immunology*
D016227:Benzoquinones; C508606:CXCL8 protein, human; D005233:Fatty Alcohols; D006018:Glycols; D016209:Interleukin-8; C513240:LTB4R protein, human; C485878:LTB4R2 protein, human; D020024:Leukotriene Antagonists; D016859:Lipoxygenase Inhibitors; D010879:Piperazines; D018102:Receptors, Leukotriene B4; D013777:Tetrazoles; D013844:Thiazoles; C062137:U 75302; C085131:1-((4,5-bis(4-methoxyphenyl)-2-thiazoyl)carbonyl)-4-methylpiperazine; D007975:Leukotriene B4; C036837:2,3,5-trimethyl-6-(12-hydroxy-5,10-dodecadiynyl)-1,4-benzoquinone; D008049:Lipase; D019286:Endopeptidase K; C063823:LY 255283