Leukotriene B4 mediates T lymphocyte migration in response to diverse stimuli Maria Fernanda de Souza Costa,*,1 Raquel de Souza-Martins,*,1 Mariana C.

Herein, we investigated the involvement of the 5-LO-derived lipid mediator LTB4 in T cell migration. When injected into the i.pl. space of C57BL/6 mice, LTB4 trig-gered T lymphocyte mobilization in vivo, a phenome-non also observed in in vitro chemotaxis assays. The i.pl. injection of Escherichia coli endotoxin (LPS) trig-gered increased levels of LTB4 in pleural cavities. The in vivo inhibition of LTB4 biosynthesis by the 5-LO in-hibitor zileuton or the FLAP inhibitor MK886 attenu-ated LPS-induced T cell accumulation into pleural cavities. Accordingly, 5-LO KO mice failed to recruit T cells into the inflammatory site after i.pl. LPS. An-tagonists of the high-affinity LTB4 receptor BLT1, CP105,696, and LY292476 also attenuated LPS-in