Yonago Acta medica 1996;37:219-226

Killing of Newborn Trichinella spiralis Larvae by Macrophage Cell Lines

Soji Fukumoto, Takahiko Tanigawa*, Yoshinori Tanaka*, Takeo Tanihata and Kazumitsu Hirai

Department of Medical Zoology and *Department of Bacteriology, Faculty of Medicine, Tottori University, Yonago 683, Japan

About half of the newborn larvae (NBL) of Trichinella sptralis were adhered by simian virus 40-transformed macrophages, A640-BB-2 (A2 cells) after 24 h incubation in the presence of immune mouse serum, although none of the NBL were adhered by A2 cells in the absence of the specific antibodies. All of the NBL were adhered by A2 cells after 72 h incubation in the presence of lipopolysaccharide (LPS), and were killed in either condition with or without interferon-γ. The NBL kining rates by A2 cells did not necessarily increase with the increased N02- concentration. NBL were also killed when cocultivated with activated macrophages in the presence of NG-monomethyl-L-arginine (L-NMMA), a specific inhibitor of nitric oxide synthesis. No significant difference was observed in the antibody-dependent killing of NBL by clone 16 and clone C3C of macrophage cell line J 774. Clone 16 can produce H202 by stimulation with PMA (Phorbol 12-myristate 13-acetate), but clone C3C cannot. These results suggested that NBL are not killed by oxygen radicals or nitric oxide, but by some unknown factors associated with LPS-activated macrophages.

Key words: cell line macrophage; lipopolysaccharide; nitric oxide; oxygen radical; Trichinella spiralis

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