Study Of T And B Cell Epitopes On Partial Protein Of Hepatitis C Virus

Hepatitis C virus is the major causative agent of non-A, non-b acute and chronic hepatitis. It is notable for the high rate of chronic infection, which occurs in nearly all infected individuals. In some individuals, cirrhosis and HCC develop 21 and 29 years on average after infection, respectively. HCV is a positive-strand RNA virus included in the family Flaviviridae. The error-prone nature of viral RNA polymerases provides the biochemical basis for the extensive genetic variation among sequenced isolates known as quasispecies. It is suggested that quasispecies, which escape from the host's immune response, contribute to persistence of infection. In this study, we observed the HCV quasispecies evolution in two HCV carriers and one individual with self-limited HCV infection. Our focus is on HVR1 and a region of NS3, which contain B and T lymphocyte epitopes respectively.In the study, HVR1 and a region of NS3 in blood samples taken in 1991,1994 and 1996 were amplified by RT-PCR, subcloned and sequenced. HLA type of the three persons was determined using antibodies. The sequences were analyzed by combining free bioinformatical software, relational database and word process tool of MS Office 97, including a T-cell epitope prediction software developed by ourselves using MS Visual C++, which can be downloaded freely from http://www.fmmu.edu.cn/GUOTIF.htm.