Surface display of antigens on bacterium like particles elicits specific humoral Th1 type responses. A novel surface display on bacterium like particles elicits mucosal and systemic responses.

RAYA-TONETTI, M.F.; SACUR, JACINTO; PADILLA FRANZOTTI, C.; VILLENA, J.; VIZOSO PINTO, M. G.

La Plata

Congreso; Reunion Conjunta SAIC SAI SAFIS; 2018

Nasal vaccination is a promising alternative to parenteral vaccinationas it is non-invasive and elicits antigen-specific responsesboth systemic and locally. Previous studies showed that bacterium-like-particles (BLPs) are effective stimulators of local and systemicimmune responses when administered intranasally. Herewe explored the use of BLPs, derived from the immunomodulatorystrain Lactobacillus rhamnosus IBL027 (IBLP027) as a display platformof a model antigen, the Venus fluorescent protein using a novellysin motif (LysM5) as anchor.The ability of the LysM5-Venus-IBLP027 complex to induce specificsystemic and respiratory humoral immune responses after intranasalimmunization was evaluated. Six-week-old BALB/c mice wereimmunized with LysM5-Venus-IBLP027 (40 and 20 ug of recombinantprotein/mouse). Nasal administration of His-LysM5-Venus aloneor intraperitoneal administration of His-LysM5-Venus with completeFreund?s adjuvant were used as controls. Mice were primed at day0 and boosted at day 14. The levels of specific serum IgG, IgG1and IgG2a and the levels of broncho-alveolar lavage (BAL) totalIg (IgT) were evaluated ten days after priming or boosting. It wasobserved that His-LysM5-Venus is immunogenic when it is administeredwith complete Freund?s adjuvant, since specific IgT and IgGantibodies were detected after priming. In addition, the other groupsdid not induce an obvious respiratory or systemic humoral response(P