| Description | 1Laboratório de Desenvolvimento de
Vacinas, Instituto Butantan, São Paulo, Brazil;
2Programa de Pós-Graduação Interunidades
em Biotecnologia, Universidade de São
Paulo, São Paulo, Brazil; 3Université Claude
Bernard Lyon 1 (UCBL1), Villeurbanne,
69100, France; 4Laboratório de
Imunopatologia, Instituto Butantan, São
Paulo, Brazil; 5Laboratório de
Biomarcadores e Inflamação, Instituto
Gonçalo Moniz, Fundação Oswaldo Cruz,
Salvador, Brazil; 6Istituto di Biochimica
e Biologia Cellulare, Consiglio Nazionale
delle Ricerche, Napoli, Italy; 7Stazione
Zoologica Anton Dohrn, Napoli, Italy;
8Shenzhen Institute of Advanced
Technologies (SIAT), Chinese Academy of
Sciences (CAS), Shenzhen, China Division of
Infectious Diseases, Boston Children’s
Hospital, Boston, MA, USA; 9Division of
Infectious Diseases, Boston Children’s
Hospital, Boston, MA, USA | pt_BR |
| Abstract | Purpose: The use of adjuvants can significantly strengthen a vaccine’s efficacy. We sought
to explore the immunization efficacy of bacterial outer membrane vesicles (OMVs) displaying
the Schistosoma mansoni antigen, SmTSP-2, through a biotin-rhizavidin coupling
approach. The rationale is to exploit the nanoparticulate structure and the adjuvant properties
of OMVs to induce a robust antigen-specific immune response, in light of developing new
vaccines against S. mansoni.
Materials and Methods: OMVs were obtained from Neisseria lactamica and conjugated
with biotin. The recombinant SmTSP-2 in fusion with the biotin-binding protein rhizavidin
(rRzvSmTSP-2) was produced in E. coli and coupled to biotinylated OMVs to generate
an OMV complex displaying SmTSP-2 on the membrane surface (OMV:rSmTSP-2).
Transmission electron microscopy (TEM) and dynamic light scattering analysis were used
to determine particle charge and size. The immunogenicity of the vaccine complex was
evaluated in C57BL/6 mice.
Results: The rRzvSmTSP-2 protein was successfully coupled to biotinylated OMVs and
purified by size-exclusion chromatography. The OMV:rSmTSP-2 nanoparticles showed an
average size of 200 nm, with zeta potential around – 28 mV. Mouse Bone Marrow Dendritic
Cells were activated by the nanoparticles as determined by increased expression of the costimulatory
molecules CD40 and CD86, and the proinflammatory cytokines (TNF-α, IL-6
and IL-12) or IL-10. Splenocytes of mice immunized with OMV:rSmTSP-2 nanoparticles
reacted to an in vitro challenge with SmTSP-2 with an increased production of IL-6, IL-10
and IL-17 and displayed a higher number of CD4+ and CD8+ T lymphocytes expressing
IFN-γ, IL-4 and IL-2, compared to mice immunized with the antigen alone. Immunization of
mice with OMV:rSmTSP-2 induced a 100-fold increase in specific anti-SmTSP-2 IgG antibody
titers, as compared to the group receiving the recombinant rSmTSP-2 protein alone or
even co-administered with unconjugated OMV.
Conclusion: Our results demonstrate that the SmTSP-2 antigen coupled with OMVs is
highly immunogenic in mice, supporting the potential effectiveness of this platform for
improved antigen delivery in novel vaccine strategies. | pt_BR |
