Adjuvants Screening Of HSV-2 GD Subunit-Related Vaccine And Immunological Evaluation Of The Vaccines

Herpes simplex virus type 2?HSV-2?is a genital herpes virus which is widely spread around the world.It has the characteristics of being neurotropic,and recurring.It is the main factor of the occurrence and recurrence of genital herpes.HSV-2 is sexually transmitted and estimated to infect 500 million people worldwide including23.6 million new infections per year,and the risk of HIV-1 infection in its positive patients will increase 2-3 times.At present,patients with obvious symptoms of HSV-2 infection usually choose antiviral drugs such as,acyclovir for clinical treatment.However,this method can only slightly relieve clinical symptoms,but cannot completely eliminate the virus and prevent the occurrence of recurrent infection.Some asymptomatic infections have increased the possibility of virus transmission due to the silent shedding of the viruses.Based on the prevalence of HSV-2 infection and the limitations of existing clinical interventions,there is an urgent need to develop an effective HSV-2 vaccine.The research on the HSV-2 vaccine can be traced back to the 1930s,and it is usually divided into two types:prophylactic and therapeutic.In the past hundred years,researchers had made unremitting research,but there is still no approved effective HSV-2 vaccine.With the deepening understanding of herpes simplex virus and the experience of the repeated failures in the development of corresponding vaccines,researchers have found that in addition to inducing a strong antibody response,an effective prophylactic HSV-2 vaccine also needs to stimulate CD4⁺and CD8⁺T cell responses;Strengthen the innate and mucosal immune responses to quickly respond to the local invasion of the viruses and effectively remove alien pathogens and infected cells.In addition to the ability to enhance the immunogenecity of subunit antigens,adjuvants can also direct the immune system toward particular arms of the immune response needed for the resistence of HSV-2.Therefore,the selection of adjuvants is particularly important in the development of vaccines.MF59 has good compatibility with a variety of soluble antigens;The new series of human vaccine adjuvants AS?adjuvant System,AS?developed by Glaxo Smith Kline?GSK?has proven its effectiveness in a variety of commercially available vaccines or clinical trials;BLP as a mucosal adjuvant or antigen carrier for various anti-mucosal pathogen vaccines,has a significant immune stimulating effect.Therefore,in this study,the traditional Al?OH?₃ and MF59 adjuvants were selected as controls,and AS02,AS03 in the GSK adjuvant system were first applied to the study of HSV-2 prophylactic subunit vaccine to compare the immune enhancement effects and immune response bias of four systemic adjuvants and antigens;Exploring the immunostimulatory effect of the novel mucosal adjuvant BLP in the intranasal immunized HSV-2 recombinant subunit vaccine and focusing on the analysis from the perspective of induced mucosal immunity.All these adjuvants were administered with truncted glycoprotein D?1-285aa,gD2??or non-specific binding of BLP to recombinant fusion protein gD2-PA?which is an important envelope glycoprotein that mediates the fusion of virus and host cell membrane and has many T cells and neutralizing epitopes to prepare prophylactic subunit vaccines and recombinant subunit vaccine for mucosal immunity,and these vaccines were then evaluated in a mouse model.The full text is divided into the following two parts:?1?Construct pSecTag2A-gD2 plasmid and express it in HEK293T eukaryotic expression system and pyrify to obtain gD2 and gD2-PA target proteins in large quantities;?2?Prepare the above five immunogens to immunize mice three times,and perform immunological evaluation on them.Conclusions:?1?The four systemic adjuvants and the new mucosal adjuvant BLP had good immunogenicity,and the corresponding vaccines showed different degrees of protection against lethal dose HSV-2 challenge;?2?Systemic vaccine:AS02 can induce the highest level of antibody responses.In Th-biased experiments,Al?OH?₃,MF59 and AS03 adjuvants had Th2 type humoral immune bias,while AS02 was slightly biased to induce relatively balanced Th1/Th2 response,which can induce both humoral and cell-mediated immune responses,and can remove the viruses completely,have 100%survival rate of mice after challenge;?3?Mucosal immunization group:The recombinant fusion protein gD2-PA-BLP group can effectively remove viruses in the genital tract only by inducing a high level of mucosal-specific IgA antibody response,so it is a potential recombinant subunit vaccine for mucosal immunity.