IWAKURA Yoichiro Tokyo University, Institute of Medical Science, Professor, 医科学研究所, 教授 (10089120)
YANO Akihiko Chiba University, Graduate School of Medicine, Professor, 大学院・医学研究院, 教授 (20135122)
AOSAI Fumie Chiba University, Graduate School of Medicine, Associate Professor, 大学院・医学研究院, 助教授 (80150316)
|Budget Amount *help
¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 2003 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 2002 : ¥2,200,000 (Direct Cost : ¥2,200,000)
By using our own made cDNA microarray system composed with around 15,000 clones established by using mRNA from normal mice, Toxoplasma gondii-infection-induced genes were analyzed.
Five gene groups, beta2-microglobulin, DMR-N9, spot 14,teststeron, and an unknown (tentatively named as T.g.Res.X) were picked up. T.g.Res.X was shown to express in a resistant strain to T.gondii infection when the mRNA expression was examined by comparing between a WT resistant strain (BALB/c) and a WT susceptible strain (C57BL/6) and also comparing between WT and IFN-γ knockout (GKO) BALB/c mice.
WT C57BL/6, WT BALB/c, and GKO mice were infected with cysts of T.gondii perorally. Analysis included ophthalmic examinations, fluorescein angiography (FA), a quantitative competitive polymerase chain reaction (QC-PCR) assay, reverse transcription (RT)-PCR for IFN-γ and stage conversion markers and cDNA microarmy assay
In WT C57BL/6 mice, T.gondii was detected in the order Of the brain, retina, choroid, sclera end optic nerve (ON). The highest T.gondii load was observed in the posterior retina, and was much greater than that in WT BALB/c mice. In GKO mice, disseminated infection was evident and the T.gondii load was highest in the choroid, and ON. IFN-γ mRNA expression in WT C57BL/6 mice was higher than that in WT BALB/c mice after infection. Tachyzoites existed in GKO mice, while bradyzoites existed in WT C57BL/6 mice FAG showed dye leakage from the retinal capillaries of GKO mice.
The T.gondii load in the retina in the susceptible WT strain continued to increase, unlike in the resistant WT strain. IFN-γ was shown to regulate the T gondii load and interconversion in the eye. A toxoplasmic vasculitis model was established with GKO mice and assay systems with QC-PCR and FA.
Experiments are now under way to define the toxoplasmic retinochoroiditis related genes by using cDNA microarray system