The Clone,Expression ,and Activity Assay Of Partial Sequence Of TTV,and Study On Its Pathology And Epidemiology

Part of TTV sequence from the serum of patients of no A-G hepatitis with the nest PCR primer designed on the reported sequence of TTV ORF2 was extracted. The sequence cloned to PQE-30 vector is proved to be identical to that of Japan strain for 96%. The recombined vector is transformed into JM1O9, the target protein is expressed after induction. The recombined protein is about 12.5 KD in SDS-page, it is about 22.33% of the total protein of the E.coli, and as same as expected protein. The expressed protein was detected by ELISA.Twenty-one liver slices of different person were in situ-hybridized with probe of above TTV gene fragment labeled with Digoxin and consecutive slice dyed by HE in order to study the pathological changes. The result shows that the positive signal is blue blots and granulation, locating mainly in the nuclear of hepacytes, and it is distributed evenly in the liver tissue and liver-phlic. Nine are positive in Twenty-one cases. It is observedthat the pathological changes are in Gl and Si phases, and its damage to the liver tissue is not serious.The epidemiology was studied with 246 sera originated different person using two pairs of nest PCR primer of TTV ORF 1, and TTV ORF2 and the expressing proteins of ORF2. The results show that positive rate of TTV DNA ORF 1, TTV DNA ORF2 and anti-TTV is 16%, 10.7%, 25.3%; 10.0%, 16.7%, 16.7%; 47.5%, 42.5%, 22.5%; 32.9%, 37.1%, 28.5%; 20.0%, 26.7%, 13.3%; 16.7%, 16.7%, 33.3%; 23.8, 38.1%, 23.8%; 61.1%, 50%, 44.4%, responding to 75 paid blood donors, 30 patients with HAV, 40 patients with HBV, 35 patients with HCV, 15 patients with HDV patients, 12 with 11EV, 21 patients with HGV and 18 patients with non A-U, respectively. The statistic analysis shows that the infection rate in patients with HAy and 11EV is lower than that of others, there is no difference in TTV ORF 1 and ORF2 DNA, and there is no relation between TTV antibody and TTV DNA.The conclusion is that TTV infection exists in Chinese and the sequence of the virus is almost same as those of Japan, and TTV isliver-phlic, but its damage to liver tissue is not serious. Anti-TTV ORF2 IgG exists, but is not related to TTV DNA. The foundation has been built for further study of TTV...