Vacinas de administração nas mucosas baseadas em vesículas extracelulares de parasitas

Two major objectives are defined: 1) to utilize Giardia EVs as a platform for intranasal vaccine delivery, validated with surface antigen of hepatitis B and plasmid containing information for this same protein, and with the spike protein of SARS-CoV-2; 2) to develop a bivalent vaccine for developing countries in alignment with the United Nations' 2030 agenda - simultaneously encapsulating Giardia EVs and hepatitis B surface antigen in glucan microparticles as the basis for an oral bivalent vaccine, protecting hepatitis B and giardiasis. These main objectives will be achieved through a set of secondary objectives, which will be fulfilled by the tasks outlined in the project. Secondary objectives: a) To explore the optimal approach for introducing antigens (recombinant protein and DNA) into EVs b) To investigate the polymer functionalization. c) To investigate the coating method of EVs with cationic polymer. d) To investigate the loading method of glucan microparticles with both antigens (Giardia EV and hepatitis B surface antigen). e) To investigate the immunomodulatory effect of coated EVs. f) To investigate the biodistribution of EVs (uncoated, coated, and encapsulated in glucan microparticles) following nasal and oral administration. g) To investigate the immunological response generated after oral administration of the bivalent vaccine. h) To investigate the immunological response generated by the nasal hepatitis B vaccine. i) To investigate the immunological response generated by the nasal SARS-CoV-2 vaccine. It is worth noting that after validation of the Giardia EVs platform with these antigens, the platform may be used with other antigens. Intranasal vaccines are particularly useful not only for their ease of administration but also for providing additional protection through the production of secretory IgA (sIgA) and cellular immune response in the nasal mucosa and, generally, also in the vaginal mucosa. Thus, the SARS-CoV-2 antigen is chosen because, besides representing the utility of these vaccines in preventing respiratory infections, the group already has good experience with this antigen (studies ongoing and results not yet published). In the case of hepatitis B, in addition to extensive experience with this antigen, the induction of antibodies in the vaginal mucosa will provide greater protection since it is a sexually transmitted disease. Finally, it is intended to validate EVs not only as adjuvants for protein antigens but also with genetic material. The choice of DNA over mRNA is because the group already has some experience with intranasal DNA vaccines, which in terms of methodologies ensures that the group will be able to progress more rapidly in various project tasks. Obtaining promising results will signal that the platform has many possibilities of working equally well or even better with mRNA.