Improvement of the cellular and humoral immune responses to a recombinant nucleoprotein infl uenza vaccine, by Ribi Adjuvant System

SANCHEZ, MARIA VICTORIA; CARGNELUTTI, DIEGO ESTEBAN; SCODELLER, EDUARDO

Kiel

Congreso; 23rd Annual Meeting of the Society for Virology; 2013

Society for Virology. German Association for the Control of Virus Diseases

A universal vaccine against infl uenza capable to induce a heterosubtypic immunity is persuading by many researchers. An attractive approach to achieve this goal is using conserved viral antigens, as the virus nucleoprotein, formulated with novel adjuvants to promote and improve effi cient antigen specifi c immune response. In this work we have studied the effect induced for the monophosphoryl lipid A and trehalose dimycolate, known as Ribi Adjuvant System (RAS), in the immune response of mice immunized with the recombinant nucleoprotein (rNP). For this, the rNP was produced in E.coli and then formulated with RAS to immunize BALB/c mice by the subcutaneous route . The analysis of the humoral immune response and the IgG2a/IgG1 ratio, suggested a Th1 bias response (Fig.1).The production of cytokines from mice immunized with NP-RAS,showed a signifi cant increase in the production of IFN-γ and a decreased production of IL-10 and IL-4 compared with the controls without RAS (Fig.2). In addition,these results were compared when Freund?s adjuvants were used, and similar results were obtained,suggesting that a similar approach may be possible to enhance the performance of a vaccine containing NP. The analysis of the immune responses showed that immunizations with NP-RAS, enhancement the humoral and cellular immune responses as compared to unadjuvanted formulation. These strategies can contribute of the development of more effective vaccines against this important human pathogen.