Innovation and Development

Substantial Step Forward: Therapeutic Vaccine for Anti-HBV

The pathogenic microorganism research group of the Institute of Microbiology, CAS has studied the immunological function of heat shock protein gp96 since 1997. They have explored the cellular immunity mediated by gp96 in the HBV infection and have made important progress. In 2011, based on previous research, which shows that the regulatory T cells （Treg）may play a negative role in the gp96-mediated T-cell responses, the research team led by Dr. Meng Songdong further found that eliminating Treg could remarkably increase the T cell immunological competence and anti-tumor activity by gp96, which provides bases for enhancing the immunological activity of gp96 vaccine and may help to design more potent autologus gp96 cancer vaccines which are currently being used in clinical trials. In the HBV transgenic mouse model, gp96 therapeutic vaccine was found to efficiently activate T cell immune response and eliminate HBV virus; gp96 adjuvant vaccine could effectively activate HBV-specific T cell responses and decrease Tregs in transgenic mouse. After 5-8 weeks of immunization, the viral S antigen in the serum was decreased by more than 50%, the copy numbers of viral DNA were decreased by more than 1000 times, and more than 95% of the virus in liver were eliminated, which demonstrate that gp96 therapeutic vaccine could effectively break the immune tolerance and activate T cell response to inhibit HBV. This research provides basis for developing gp96 based HBV therapeutic vaccine. Meanwhile, it is the first time to express recombined gp96 protein with immunological competence in the yeast Hansenula, facilitating for researching gp96 biological function and developing adjuvant vacciness. These results have been published in the Cancer Immunology Immunotherapy，Vaccine and Journal of Biotechnology respectively in 2011, and two Chinese inventive patents have been applied.

Breakthrough in Research on Cascaded Laser Wakefield Accelerator

A research group led by Xu Zhizhan and Li Ruxin of the State Key Laboratory of High Field Laser Physics, Shanghai Institute of Optics and Fine Mechanics,CAS published a paper on Phys. Rev. Lett. 107，035001（2011））on July 15th, which reports the scheme of firstly adopting an all-optical cascaded laser wakefield accelerator using ionization-induced injection, and it successfully separated and controlled the two basic physical process of electron injection and acceleration. The experiment has made groundbreaking achievement of producing quasi- monoenergetic electron beams with near-GeV energy, ultrahigh accelerating gradient of 187 GV/m, etc. The successful realization of the Cascaded Laser Wakefield Accelerator has provided feasible approach to generate high-performance monoenergetic electron beam with 10-GeV-class or higher energy, and it has a far-reaching influence on the table-top particle accelerator.