Preparation And Immune Activity Of Tumor Vaccine Based On Thomsen Friedenreich Antigen And Chitosan Oligosaccharide Endogenous Adjuvant

Thomsen-friedenreich(TF)antigen,a typical tumor-associated sugar antigens(TACAs),which are present in large quantities on the surface of most cancer cells such as breast cancer and pancreatic cancer and serve as markers.TF antigen plays an important role in activating the immune system and is often used in tumor immunotherapy.In the process of vaccine use,in order to activate or enhance the immune system of the body,it is often necessary to add adjuvants,which are compatible with antigens to immunize the body and enhance the immune effect of the vaccine.Chitosan oligosaccharides(COS),also known as chitosan oligosaccharides or oligochitosan,is an oligosaccharide.It is the only cationic alkaline amino oligosaccharide with positive charge in nature.COS is easy to dissolve in water and has low viscosity.It has good biocompatibility.At the same time,it has a variety of biological activities,such as auxiliary antigen,enhancing immune stimulation,limiting the metastasis and escape of tumor cells and so on.In addition,it has been found that only when antigen and adjuvant are presented to antigen presenting cells(APC)can T cells be activated effectively and the immune activation effect of the vaccine be fully realized.Therefore,chito-oligosaccharide was selected as vaccine adjuvant in this study.A tumor vaccine based on TF(Thomsen-Friedenreich)antigen and chitosaccharide as endogenous adjuvant was designed.Specifically,firstly,using galactosamine hydrochloride as raw material,TF disaccharide block was efficiently synthesized with 9.8% total yield through 10 chemical synthesis steps.Secondly,the antigenic part of tumor vaccine TF-CRM197 was prepared by covalently coupling TF glycogroup with CRM197 carrier protein.Finally,the target tumor vaccine TF-CRM197-COS was obtained by covalently combining glycoprotein TF-CRM197 with COS adjuvant activated by sulfcapol group.At the same time,TF-BSA glycoprotein was prepared as antigen coating substrate.The results showed that 7.2 TF antigens were covalently bound to each protein molecule of TF-CRM197 glycoprotein.Then,through the implementation of the immune process,the animal level immunological evaluation of the vaccine was carried out.Female Balb/c mice aged 6 ～ 8 weeks were immunized,and the antibody titer of mouse serum was measured.The results showed that the TF-CRM197-COS group designed in this subject could produce high titer IgG antibody level(the value was 25600).The antibody titer level of TF-CRM197-COS group was significantly different from that of the antigen/adjuvant physical mixture group or adjuvant group,showing more immune stimulation effect.In conclusion,the TF-CRM197-COS tumor vaccine prepared in this paper,which co-loaded TF antigen with chitosan adjuvant for vaccine delivery,has excellent immunogenicity and shows good potential for application.