Preparation And Characterization Of Monoclonal Antibodies To Hepatitis A Virus L-8 Strain

Heptatitis A is an infectious disease and harmful to human health, the pathogen is hepatitis A virus (HAV) which is a member of the Picornaviridae, and there are only one serotype and a lot of sub-types in the global wide. There is still high incidence of hepatitis A in the developping country. The wide-spread use of HAV live attenuated vaccine and inactive vaccine has provided efficient ways for controlling the epidemic of heptatitis A. while, some people got hepatitis A after injecting vaccines. In order to distinguish the viral capsid could result from hepatitis A vaccines or from natural infection, the identification of the virus strains is necessary. In 1975, KO|¨hler and Milstein have developped hybridoma technique for producting monoclonal antibody(McAb). McAb directed toward an epitope were used for analyzing antigen relationsamong types or strains of virus, and there are strong specification, high susceptibility, low expense and better repeatability, So we can distinguish hepatitis A strains with anti-HAV monoclonal antibody.L-8 strain of hepatitis A virus belonging to IB sub-type was gotten when hepatitis A outbreaked in 1998. Now, the inavtived vaccine of L-8 strain has been used for preventing hepatitis A. We choosed L-8 strain as the immunogen. BALB/c mice were immunized with the LU-8 strain , and the spleen cells from BALB/c mice were fused with SP2/0 myeloma cell, and were cultured in HAT. The supernatant of hybridoma cells were screened by ELISA, cloned by limiting dilution, purified, and identified. We have gotten one hybridoma cell line which could secret monoclonal antibodies against HAV Ag. The titer of McAbs in cell culture and ascites fluids were 1:64;1:1000. The chromosome of the hybridoma cells were analyzed for 80～90, whichshowed the effection of two cell fusing. It was proved the McAb could react with both L-8 strain and H-2 strain in inderected ELISA. The McAb had high binding ability to L-8 strain. It was proved that we have developped hybridoma cell lines which could secret monoclonal antibody against L-8 strain of hepatitis A; The assay distinguished L-8 strain from H2 strain showed that the identification is very difficult with specifical antibody, because there are similar epitopes in different strains of the same sub-type.