RESUMO
Materials that allow modular, defined assembly of immune signals could support a new generation of rationally designed vaccines that promote tunable immune responses. Toward this goal, we have developed the first polyelectrolyte multilayer (PEM) coatings built entirely from immune signals. These immune-PEMs (iPEMs) are self-assembled on gold nanoparticle templates through stepwise electrostatic interactions between peptide antigen and polyanionic toll-like receptor (TLR) agonists that serve as molecular adjuvants. iPEMs do not require solvents or mixing, offer direct control over the composition and loading of vaccine components, and can be coated on substrates at any scale. These films also do not require other structural components, eliminating the potentially confounding effects caused by the inherent immune-stimulatory characteristics of many synthetic polymers. iPEM loading on gold nanoparticle substrates is tunable, and cryoTEM reveals iPEM shells coated on gold cores. These nanoparticles are efficiently internalized by primary dendritic cells (DCs), resulting in activation, selective triggering of TLR signaling, and presentation of the antigens used to assemble iPEMs. In coculture, iPEMs drive antigen-specific T cell proliferation and effector cytokines but not cytokines associated with more generalized inflammation. Compared to mice treated with soluble antigen and adjuvant, iPEM immunization promotes high levels of antigen-specific CD8(+) T cells in peripheral blood after 1 week. These enhancements result from increased DC activation and antigen presentation in draining lymph nodes. iPEM-immunized mice also exhibit a potent recall response after boosting, supporting the potential of iPEMs for designing well-defined vaccine coatings that provide high cargo density and eliminate synthetic film components.
Assuntos
Apresentação de Antígeno/imunologia , Antígenos/imunologia , Linfócitos T CD8-Positivos/imunologia , Eletrólitos/química , Ouro/química , Nanopartículas Metálicas/química , Polímeros/química , Adjuvantes Imunológicos/química , Animais , Antígenos/química , Células Cultivadas , Células Dendríticas , Eletrólitos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/química , Peptídeos/imunologiaRESUMO
Because of their large surface area, the lungs appear an attractive route for noninvasive vaccine delivery, harboring the potential to induce local mucosal immune responses in addition to systemic immunity. To evoke adaptive immunity, Ags require the addition of adjuvants that not only enhance the strength of the immune response but also determine the type of response elicited. In this study, we evaluate the adjuvant characteristics of polyelectrolyte microcapsules (PEMs) consisting of the biopolymers dextran-sulfate and poly-L-arginine. PEMs form an entirely new class of microcapsules that are generated by the sequential adsorption of oppositely charged polymers (polyelectrolytes) onto a sacrificial colloidal template, which is subsequently dissolved leaving a hollow microcapsule surrounded by a thin shell. Following intratracheal instillation, PEMs were not only efficiently taken up by APCs but also enhanced their activation status. Pulmonary adaptive immune responses were characterized by the induction of a strongly Th17-polarized response. When compared with a mixture of soluble Ag with empty microcapsules, Ag encapsulation significantly enhanced the strength of this local mucosal response. Given their unique property to selectively generate Th17-polarized immune responses, PEMs may become of significant interest in the development of effective vaccines against fungal and bacterial species.
Assuntos
Implantes Absorvíveis , Adjuvantes Imunológicos/administração & dosagem , Cápsulas/administração & dosagem , Interleucina-17/imunologia , Pulmão/imunologia , Vacinação/métodos , Adjuvantes Imunológicos/síntese química , Animais , Células Apresentadoras de Antígenos/imunologia , Antígenos/administração & dosagem , Antígenos/imunologia , Lavagem Broncoalveolar , Cápsulas/síntese química , Sulfato de Dextrana/imunologia , Eletrólitos/imunologia , Feminino , Citometria de Fluxo , Imunidade nas Mucosas/imunologia , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Peptídeos/imunologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
The antibodies to streptococcal group A polysaccharide (A-PS) have been obtained upon immunization of BALB/c mice with A-PS conjugated with synthetic polyelectrolytes (PEL). Prolonged immunization in the majority of cases revealed antibodies to cross-reactive determinant of A-PS reacting with human and mouse epithelium of the thymus and basal skin layer. These antibodies belong to autoantibodies. Later on, after the beginning of immunization some animals produced antibodies reacting with cellular nuclei. The formation of autoantibodies to nuclei is not related to crossreactions with A-PS, because A-PS do not inhibit these reactions. No antibodies reacting with the epithelial cells or with cellular nuclei have been observed upon immunization with A-PS in Freund adjuvant or with PEL alone. The production of autoantibodies to cellular nuclei is probably a result of immunoregulatory disorders associated with the damage of thymus epithelium by autoantibodies during immunization with A-PS conjugated with PEL.
Assuntos
Reações Antígeno-Anticorpo , Autoanticorpos/imunologia , Núcleo Celular/imunologia , Eletrólitos/imunologia , Imunização/métodos , Polissacarídeos Bacterianos/imunologia , Pele/imunologia , Streptococcus pyogenes/imunologia , Timo/imunologia , Resinas Acrílicas/imunologia , Animais , Anticorpos Antibacterianos/análise , Antígenos de Bactérias/imunologia , Reações Cruzadas , Epitélio/imunologia , Epitopos/imunologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Povidona/análogos & derivados , Povidona/imunologiaRESUMO
A synthetic polysaccharide immunogen has been obtained by the conjugation of S. typhimurium nonimmune O-polysaccharide with a membrane-active adjuvant (the copolymer of acrylic acid and N-vinylpyrrolidone). The importance of the method used for the conjugation of O-polysaccharide with a synthetic carrier in enhancing its immunogenicity is shown.