Effects And Immune Mechanism Of Different Adjuvants On Polyepitope Chimeric Antigen M.RCAg-1

As one of the three major infectious diseases in the world, malaria is still a threat to human health. According to the most recent data from WHO, about 3.2 billion people remain at risk of malaria. In 2015 alone, there were an estimated 214 million new cases of malaria and 438 000 deaths. The emergence and spread of drug-resistant parasites and insecticide-resistant Anopheles mosquito vectors make traditional prevention and treatment of malaria a big hurdle, which enhance the demand of safe and cost-efficient therapeutic malaria vaccine all over the world.The immune effects were not satisfacted when Plasmodium falciparum erythrocytic stage vaccine candidates were singlely or simple combine used. Therefore constructing multi-antigens and multi-epitopes recombinant protein vaccine become one direction for blood stage malaria vaccine research. Our lab previously has constructed malariarandom constructed antigen-1(M.RCAg-1) using’epitode reshuffling’technique. As a Falciparum polyepitope artificial random recombinant protein vaccine, M.RCAg-1 has been proved strong immunogenicity and protective in vitro and in vivo in BALB/C mice, rabbits and NHPs models.And cooperation with the Institute of Process Engineering,the Chinese Academy of Sciences,we developed a stable purification process, established asimple and feasible stable pilot-scale preparation.On the basis of previous study, we select one clinical application adjuvants, bisphosphonates,which are a class of drugs that are widely used to inhibit loss of bone mass in patients, to increase the immunogenicity of vaccine M.RCAg-1. And then evaluate the immunogenicity of M.RCAg-1 in BALB/c mice and New Zealand rabbit to find the best adjuvant and its dose. In all, our research formed the foundation for the following clinic study of M.RCAg-1.This research mainly made the following progress:1. We confirmed that the ZLD (0.05mg s.c.) was the optimal dose from the different formulation of bisphosphonates as an adjuvant on immunogenicity of M.RCAg-1 in Balb/c mouse. The growth inhibitory activity of purified IgG from immunized New Zealand rabbit was 76.7%.2. We confirmed that the ALD(0.1mg) was the optimal dose from the different formulation of ALD as an orally adjuvant on immunogenicity of M.RCAg-1 in Balb/c mouse. The growth inhibitory activity of purified IgG from immunized New Zealand rabbit was 48.6%.3. We confirmed that the ZLD (0.05mg)+MF59 was the optimal dose from the different formulation of ZLD and MF59 as an adjuvant on immunogenicity of M.RCAg-1 in Balb/c mouse. At the same time, we demonstrated that the formulation of ZLD and MF59 can not only increase the Thl cellular immune response, but also can enhance the Th2 antibody response. The growth inhibitory activity of purified IgG from immunized New Zealand rabbit was 72.5%.