Cloning And Expression Of TTV ORF1 Gene

Background and Objective: Hepatitis is a kind of infection disease which damage human health heavily. At present, it has discovered and affirmed 5 hepatitis viruses of A, B, C, D and E. At the end of 1997, the Japanese scholar Nishizawa discovered Transfusion transmitted virus (TTV) from a non-A-E hepatitis patient by Reprentational difference analysis. TTV gene unit is a kind of single strand DNA .The 3.8kb genome has been sequenced and it has two open reading frames (ORF). ORF1 locates between 589 to 2898 nucleotide, coding 770 amino acids; ORF2 possible codes non-structural protein of the virus; the virus can vertical transmission, and it's bio-characters are similar with some animal's single strand DNA virus(Parvovirus B19). Genotyping of TTV: according to reported part gene order of TTV DNA, it has high variability. To detect TTV DNA in blood serum by PCR is the maim means to diagnosis the TTV infection. It hasn't confirmed that TTV infection can cause hepatic injury and can effect liver function, but TTV can bring ALT ascending and viremia. It also evoke regionally out breaking spread and always coinfect with HBV and HCV. The infection rate of TTV during non-A-E hepatitis patients is high, and it may be the main etiological factor for non-A-E hepatitis. The current domestic investigation data of TTV is deficiency. The significance of this experiment is to set up a prokaryotic expression vector of TTV-ORF1 DNA and to make it high performance expressed. That's offering a fundament for researching TTV's ELISA detect and it's vaccine antigen.