IBP Scientists Made New Research Progress on the Therapeutic Vaccine for Chronic Hepatitis B Infection
Persistent HBV infection still represents a substantial threat to the public health, despite the existence of effective prophylactic vaccines. More than 2 billion people are infected with hepatitis B virus (HBV), and 350 million become chronic HBV (CHB) carriers worldwide. Nearly one million people die from hepatitis B-related diseases every year. Thus, there remains an urgent need for effective treatment strategies to limit the enormous burden of viral hepatitis on global health.
In a recent study published in Hepatology, a group led by Dr. FU Yang-Xin and Dr. PENG Hua from IBP-UT Group for Immunotherapy, Institute of Biophysics, Chinese Academy of Sciences, reported that the clinical CHB patients presented less immune tolerance to the preS1 of HBV large surface antigen. Using a well tolerate HBV carrier mice model by AAV-HBV1.3 infection, the group proved that unlike the main toleragen HBsAg in CHB infection, the preS1 domain showed less tolerant. To study whether targeting the weak tolerance of preS1 region could improve therapy gain, they explored vaccination with preS1 for HBV virions clearance. The study showed that this preS1 rather than HBsAg vaccination induced robust immune responses in the HBV carrier mice. The anti-preS1 induced in the model cleared HBV virions and could block HBV infection to hepatocytes, besides the vaccination even reduced the tolerized status of HBsAg, opening a therapeutic window for the host to respond to the HBsAg vaccine. At last, by a sequential administration of antigenically distinct preS1 and HBsAg vaccines in HBV carrier mice, HBsAg-HBsAb serological conversion could finally be induced, which is a clinical indicator for CHB cure. These results would provide new target for therapeutic vaccine to the control of CHB.
The research work was entitled “Vaccines Targeting PreS1 Domain Overcome Immune Tolerance in HBV Carrier Mice”, and was published on line in Hepatology on April 26, 2017. The study was funded by Ministry of Science and Technology of China, National Natural Science Foundation of China and Chinese Academy of Sciences.
Chinese Academy of Sciences Key Laboratory of Infection and Immunity, IBP