Co-administration of rNP with nanoparticles by subcutaneous route, induces intense humoral and cellular immune responses in BALB/c mice

ABBA, ROMINA LOURDES; SCODELLER, EDUARDO; CARGNELUTTI, DIEGO ESTEBAN; GERMANÓ, M. JOSE; SANCHEZ, M.VICTORIA

Mendoza

Congreso; XXXIV Reunión Científica Anual de la Sociedad de Biología de Cuyo.; 2016

Currently, the immune response induced by actual influenza vaccines is based on the induction of antibodies against surface viral proteins, which can neutralize the virus. These antibodies are specific of vaccine strains and do not protect against antigenic variants or new subtypes The induction of strong T cell responses to conserved internal viral proteins, as the viral Nucleoprotein, is associated with reduced disease severity as well as broad cross-reactivity protection. In recent days, the use of nanoparticles to enhance immune responses in vaccinology, has been of high interest The aim of this work is to evaluate the immune responses of a new vaccine based on recombinant influenza nucleoprotein (rNP), co-administered with non porous silica or Alumin oxide nanoparticles. To achieve this goal, groups of 5 female BALB/c mice were immunized subcutaneously with 2 doses of 10 µg of rNP alone or co-administered with 250 µg of the different nanoparticles, on day 1 and 21. Mice were sacrificed on day 42, and sera and spleens were recollected. The humoral immune response was evaluated by determination of antigen specific IgG and IgG subtypes antibodies titers by ELISA. The cellular immune response was evaluated by determination of INF-γ and IL-4 in supernatants of splenocytes re-stimulated with rNP after 72 h, by ELISA. The results showed a good humoral immune response by high IgG and IgG1subtype specific titers from mice immunized with rNP/ nanoparticles compared with rNP alone. A good production of INF-γ but not IL-4, was elicited by splenocytes from mice immunized with rNP/silica and rNP/alumina. The obtained results showed that the formulations of rNP/ silica as well as rNP/alum confer a Th1 bias response. In conclusion, the use of nanoparticles combinated with NP could be taken into account for the development of innovative vaccines against influenza.