RESUMO
We studied the feasibility of using halloysite clay nanotubes (HNTs) and carboxyl-functionalised multi-walled carbon nanotubes (COOH-MWCNTs) as antigen carriers to improve immune responses against a recombinant LipL32 protein (rLipL32). Immunisation using the HNTs or COOH-MWCNTs significantly increased the rLipL32-specific IgG antibody titres (p < 0.05) of Golden Syrian hamsters. None of the vaccines tested conferred protection against a challenge using a virulent Leptospira interrogans strain. These results demonstrated that nanotubes can be used as antigen carriers for delivery in hosts and the induction of a humoral immune response against purified leptospiral antigens used in subunit vaccine preparations.
Assuntos
Carboidratos da Dieta/análise , Fibras na Dieta/análise , Qualidade dos Alimentos , Inspeção de Alimentos/métodos , Frutas/química , Modelos Biológicos , Malus/química , Calibragem , Produtos Agrícolas/química , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Dinamarca , Carboidratos da Dieta/metabolismo , Fibras na Dieta/metabolismo , Armazenamento de Alimentos , Alimentos Geneticamente Modificados , Frutas/crescimento & desenvolvimento , Frutas/metabolismo , Análise dos Mínimos Quadrados , Modelos Lineares , Malus/crescimento & desenvolvimento , Malus/metabolismo , Análise de Regressão , Reprodutibilidade dos Testes , Solubilidade , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
Pathogenic Leptospira spp. are the etiological agents of leptospirosis, an important disease of both humans and animals. In urban settings, L. interrogans serovars are the predominant cause of disease in humans. The purpose of this study was to characterize a novel Leptospira isolate recovered from an abandoned swimming pool. Molecular characterization through sequencing of the rpoB gene revealed 100% identity with L. interrogans and variable-number tandem-repeat (VNTR) analysis resulted in a banding pattern identical to L. interrogans serogroup Icterohaemorrhagiae, serovar Copenhageni or Icterohaemorrhagiae. The virulence of the strain was determined in a hamster model of lethal leptospirosis. The lethal dose 50% (LD50) was calculated to be two leptospires in female hamsters and a histopathological examination of infected animals found typical lesions associated with severe leptospirosis, including renal epithelium degeneration, hepatic karyomegaly, liver-plate disarray and lymphocyte infiltration. This highly virulent strain is now available for use in further studies, especially evaluation of vaccine candidates.