IFN-γ抑制人成纤维细胞内弓形虫增殖机理的研究

Study of the mechanism of IFN-γ to inhibit the proliferation of Toxoplasma gondii in Human fibroblasts

目的 探讨IFN -γ抑制人成纤维细胞内弓形虫增殖的机制。方法 用反相高效液相色谱法测吲哚胺 2 ,3过氧化酶 (IDO)活性 ;用3 H -尿嘧啶 (3 H -U)掺入法测弓形虫增殖 ;用重氮化反应法测一氧化氮 (NO)浓度。结果 IFN -γ能抑制人成纤维细胞内弓形虫增殖 ,细胞培养液中色氨酸减少 ,犬尿氨酸增高 ,细胞裂解液中IDO活性增高 ;弓形虫增殖与IDO活性成负相关性。培养上清液中未检出NO。结论IFN

Aim To study the mechanism of IFN γ to inhibit the proliferation of Toxoplasma gondii in human fibroblasts Methods IDO activity was determined by reverse phase high performance liquid chromatography The extent of the inhibition of the replication of Toxoplasma gondii was measured by the incorporation of 3 H uracil The NO production by culture cells was estimated by measurement of nitrit using the Griess reagent Result IFN γ could inhibit the proliferation of Toxoplasma gondii in human fibrogblasts Substantial tryptophan catabolism was detected in both the culture medium and the cell lysate The trptophan in culture medium was depleted with the accumulation of kynurenine,high IDO activity was detected in cell lysate The correlation coefficient of Toxoplasma gondii replication and IDO activity was negtive NO wasn't detected in the culture medium Conclusion IFN γ inhibits the proliferation of Toxoplasma gondii through NO independent but IDO dependent way in human fibroblasts