Tanaka T, Omata Y, Saito A, Shimazaki K, Igarashi I, Suzuki N
Department of Veterinary Physiology, Obihiro University of Agriculture and Veterinary Medicine, Japan.
J Vet Med Sci. 1996 Jan;58(1):61-5. doi: 10.1292/jvms.58.61.
Lactoferrin (LF) is known to have broad spectrum antimicrobial properties. In regards to its defense mechanism against parasitic infection, it has shown phagocytic activity in the destruction of amastigotes, an intracellular parasitic form of Trypanosoma cruzi in macrophages. The effect of bovine lactoferrin on the intracellular growth Toxoplasma gondii parasites was examined in murine macrophage and embryonal cells. Co-cultures of host cells with the parasites were supplemented with either lactoferrin, apo-lactoferrin, holo-lactoferrin or transferrin in the culture media for varying periods. The growth activity of intracellular parasites in the host cells was determined by the measurement of selective incorporation of 3H-uracil. Supplement of lactoferrin had no effect on the penetration activity of the parasites, while development of intracellular parasites was inhibited linearly in concentration of lactoferrin. Supplement of apo-lactoferrin and holo-lactoferrin, but not transferrin showed similar effects. These suggest that lactoferrin induces the inhibitory effects on the development of intracellular parasites. Pretreatment of lactoferrin to the macrophages, however, did not show any inhibitory effects. Whereas, mouse embryonal cells preincubated with lactoferrin suppressed the intracellular growth. Thus, the action of lactoferrin to macrophages would be different from that of mouse embryonal cells.
乳铁蛋白（LF）具有广谱抗菌特性。关于其抗寄生虫感染的防御机制，它在巨噬细胞中破坏克氏锥虫的细胞内寄生形式——无鞭毛体时表现出吞噬活性。研究了牛乳铁蛋白对小鼠巨噬细胞和胚胎细胞内弓形虫寄生虫生长的影响。将宿主细胞与寄生虫的共培养物在培养基中分别添加乳铁蛋白、脱铁乳铁蛋白、全铁乳铁蛋白或转铁蛋白，并持续不同时间。通过测量3H-尿嘧啶的选择性掺入来确定宿主细胞内寄生虫的生长活性。添加乳铁蛋白对寄生虫的穿透活性没有影响，而细胞内寄生虫的发育则随着乳铁蛋白浓度的增加呈线性抑制。添加脱铁乳铁蛋白和全铁乳铁蛋白，但不包括转铁蛋白，显示出类似的效果。这些表明乳铁蛋白对细胞内寄生虫的发育具有抑制作用。然而，用乳铁蛋白预处理巨噬细胞并未显示出任何抑制作用。相反，用乳铁蛋白预孵育的小鼠胚胎细胞抑制了细胞内生长。因此，乳铁蛋白对巨噬细胞的作用与对小鼠胚胎细胞的作用不同。
