Oral vaccination using Giardia`s surface proteins

RUPIL LUCÍA LARA; SERRADELL, MARIANELA DEL CARMEN; LUJAN HUGO D

Mar del Plata

Congreso; XXXI Reunión Anual de la Sociedad Argentina de Protozoología; 2019

Vaccination is one of the most successful and cost-effective health interventions known, has played a key role in reducing diseases, disabilities and deaths caused by infectious diseases since its introduction more than 200 years ago. Although parenteral immunization is generally effective in eliminating systemic infections, it often fails to establish protective responses on mucosal surfaces, where most infectious agents initiate infection. Mucosal immunization pathways, where the oral route has significant benefits, are being increasingly sought, as they provide a painless and safe administration, with induction of systemic and local protective responses. During the development of a vaccine against Giardia lamblia, containing the entire repertoire of its Variant-specific Surface Proteins (VSPs), we proposed a new oral vaccination strategy. The use of VSPs is a mechanism that can be used to generate oral vaccines due to their outstanding resistance to proteases and to changes in pH, high immunogenicity and absence of toxicity. Meanwhile, the development of vaccines composed of Virus like particles (VLPs) has demonstrated the immunogenic potential of these particulate antigens, which exhibit on their surface repetitive arrangements of epitopes requiring less doses of antigen. In a recent study we generated a novel oral vaccination platform which takes advantage of the properties of G. lamblia VSPs in combination with VLPs harboring hemagglutinin (HA) and neuraminidase (NA) from influenza virus, as model antigens. The oral vaccination of mice with only the VLPs that were pseudotyped with VSP achieved protection from live influenza challenge and from HA-expressing tumors, highlighting that this oral vaccine was able to activate the different components of the immune system, generating antibodies in mucosa that prevent the binding and invasion of pathogens, and serum antibodies that control invasive pathogens at systemic level, in addition to an effective cellular immunity.