RESUMO
Leptospirosis is an emerging infectious disease caused by pathogenic Leptospira spp. A universal vaccine against leptospirosis is likely to require highly conserved epitopes from pathogenic leptospires that are exposed on the bacterial surface and that generate a protective and sterilizing immune response. Our group recently identified several genes predicted to encode TonB-dependent receptors (TBDR) in Leptospira interrogans using a reverse vaccinology approach. Three leptospiral TBDRs were previously described and partially characterized as ferric-citrate, hemin, and cobalamin transporters. In the current study, we designed a fusion protein composed of predicted surface-exposed epitopes from three conserved leptospiral TBDRs. Based on their three-dimensional structural models and the prediction of immunogenic regions, nine putative surface-exposed fragments were selected to compose a recombinant chimeric protein. A Mycobacterium bovis BCG strain expressing this chimeric antigen encoded in the pUP500/PpAN mycobacterial expression vector was used to immunize Syrian hamsters. All animals (20/20) vaccinated with recombinant BCG survived infection with an endpoint dose of L. interrogans (p < 0.001). No animal survived in the negative control group. Immunization with our recombinant BCG elicited a humoral immune response against leptospiral TBDRs, as demonstrated by ELISA and immunoblot. No leptospiral DNA was detected by lipL32 qPCR in the kidneys of vaccinated hamsters. Similarly, no growth was observed in macerated kidney cultures from the same animals, suggesting the induction of a sterilizing immune response. Design of new vaccine antigens based on the structure of outer membrane proteins is a promising approach to overcome the impact of leptospirosis by vaccination. KEY POINTS: ⢠Predicted surface-exposed epitopes were identified in three leptospiral TBDRs. ⢠An M. bovis BCG strain expressing a chimeric protein (rTBDRchi) was constructed. ⢠Hamsters vaccinated with rBCG:TBDRchi were protected from lethal leptospirosis.
Assuntos
Leptospira interrogans , Leptospirose , Animais , Antígenos de Bactérias , Vacina BCG , Vacinas Bacterianas , Cricetinae , Epitopos , Leptospira interrogans/genética , Leptospirose/prevenção & controleRESUMO
Leptospirosis is a major public health problem with an incidence of over one million human cases each year. It is a globally distributed, zoonotic disease and is associated with significant economic losses in farm animals. Leptospirosis is caused by pathogenic Leptospira spp. that can infect a wide range of domestic and wild animals. Given the inability to control the cycle of transmission among animals and humans, there is an urgent demand for a new vaccine. Inactivated whole-cell vaccines (bacterins) are routinely used in livestock and domestic animals, however, protection is serovar-restricted and short-term only. To overcome these limitations, efforts have focused on the development of recombinant vaccines, with partial success. Reverse vaccinology (RV) has been successfully applied to many infectious diseases. A growing number of leptospiral genome sequences are now available in public databases, providing an opportunity to search for prospective vaccine antigens using RV. Several promising leptospiral antigens were identified using this approach, although only a few have been characterized and evaluated in animal models. In this review, we summarize the use of RV for leptospirosis and discuss the need for potential improvements for the successful development of a new vaccine towards reducing the burden of human and animal leptospirosis.
Assuntos
Vacinas Bacterianas/imunologia , Leptospira/imunologia , Animais , Antígenos de Bactérias/imunologia , Humanos , Leptospira/genética , Leptospirose/imunologia , Leptospirose/microbiologia , Vacinas Sintéticas/imunologiaRESUMO
Immunisation with the C-terminal region of leptospiral immunoglobulin-like A protein (LigANI) has shown promising results against leptospirosis. We evaluated the humoral immune response and protection induced by LigANI associated with carboxyl multi-walled carbon nanotubes (COOH-MWCNTs), CpG oligodeoxynucleotides (CpG ODNs), or Alhydrogel. Animals immunised with CpG ODNs were unable to develop a humoral immune response, whereas immunisation with LigANI and COOH-MWCNTs produced a high level of IgG antibodies, similar to that with LigANI and Alhydrogel, but it was not protective. The use of carbon nanotubes as an adjuvant in subunit vaccines against leptospirosis is a novel approach for improving specific IgG production.
Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Imunoglobulina G/imunologia , Leptospira interrogans/química , Leptospirose/imunologia , Nanotubos de Carbono , Adjuvantes Imunológicos , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Cricetinae , Imunidade Humoral , Imunoglobulina G/sangue , Leptospira interrogans/imunologia , Mesocricetus , Proteínas Recombinantes/imunologia , Vacinas de Subunidades Antigênicas/imunologiaRESUMO
Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of the Leptospira genus. Vaccination with bacterins has severe limitations. Here, we evaluated the N-terminal region of the leptospiral immunoglobulin-like B protein (LigBrep) as a vaccine candidate against leptospirosis using immunisation strategies based on DNA prime-protein boost, DNA vaccine, and subunit vaccine. Upon challenge with a virulent strain ofLeptospira interrogans, the prime-boost and DNA vaccine approaches induced significant protection in hamsters, as well as a specific IgG antibody response and sterilising immunity. Although vaccination with recombinant fragment of LigBrep also produced a strong antibody response, it was not immunoprotective. These results highlight the potential of LigBrep as a candidate antigen for an effective vaccine against leptospirosis and emphasise the use of the DNA prime-protein boost as an important strategy for vaccine development.
Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Leptospira/imunologia , Leptospirose/prevenção & controle , Vacinação/métodos , Adjuvantes Imunológicos , Animais , Biópsia , Chlorocebus aethiops , Sequência Conservada , Cricetinae , Ensaio de Imunoadsorção Enzimática , Feminino , Imunidade Humoral/imunologia , Imunoglobulina A/genética , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulinas/genética , Imunoglobulinas/imunologia , Rim/patologia , Leptospirose/imunologia , Pulmão/patologia , Mesocricetus , Análise de Sobrevida , Vacinas de DNA/imunologia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/microbiologia , Células VeroRESUMO
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
Silicatos de Alumínio/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Vacinas Bacterianas/imunologia , Imunoglobulina G/análise , Leptospira interrogans/imunologia , Lipoproteínas/imunologia , Nanotubos de Carbono , Animais , Antígenos/administração & dosagem , Antígenos de Bactérias/administração & dosagem , Antígenos de Bactérias/imunologia , Dióxido de Carbono/imunologia , Argila , Cricetinae , Estudos de Viabilidade , Imunidade Humoral/imunologia , Leptospira interrogans/classificação , Mesocricetus , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/imunologiaRESUMO
Based on the fact that Synadenium grantii is used in folk medicine for the treatment of peptic ulcers and inflammatory diseases, this work describes its chemical and pharmacological properties. Pharmacological investigation of the crude bark extract showed a high antioxidant activity over several scavenger systems, such as 2,2'-azino-bis (3-ethylenebenzothiazoline-6-sulfonic acid)â¢â+, 1-diphenyl-2-picrylhydrazylâ¢, O2 â¢â- , and HOCl, as well as an enzymatic system with human myeloperoxidase and an ex vivo hemolysis system. Furthermore, the oral administration of the crude bark extract was able to reduce carrageenan-induced rat paw edema as effectively as ibuprofen. These biological activities may be associated with the presence of flavonoids and terpenes, as revealed by HPLC and NMR analyses of the crude stem bark extract. The phytochemical investigations in this study resulted in the isolation of friedelin and 3ß-friedelinol for the first time, while euphol and lanosterol were also isolated.
Assuntos
Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Euphorbia/química , Flavonoides/farmacologia , Fitoterapia , Extratos Vegetais/farmacologia , Triterpenos/farmacologia , Administração Oral , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/uso terapêutico , Antioxidantes/isolamento & purificação , Antioxidantes/uso terapêutico , Benzotiazóis/metabolismo , Compostos de Bifenilo/metabolismo , Carragenina , Edema/induzido quimicamente , Edema/tratamento farmacológico , Feminino , Flavonoides/análise , Flavonoides/uso terapêutico , Humanos , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Lanosterol/análogos & derivados , Lanosterol/isolamento & purificação , Lanosterol/farmacologia , Lanosterol/uso terapêutico , Peroxidase/metabolismo , Picratos/metabolismo , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Caules de Planta/química , Ratos Wistar , Ácidos Sulfônicos/metabolismo , Triterpenos/isolamento & purificação , Triterpenos/uso terapêuticoRESUMO
The C-terminal region of the Leptospiral immunoglobulin-like A protein (LigA) contains six carboxy-terminal Ig-like repeat domains (LigANI). Subunit vaccine preparations based on recombinant LigANI produced in Escherichia coli, are promising vaccine candidates, albeit with variable efficacy. In the present study, LigANI was expressed in the methylotrophic yeast Pichia pastoris using a 12 L bioreactor to produce mannosylated LigANI (mLigANI) for use in a vaccine preparation against leptospirosis. Hamsters immunized with a mLigANI vaccine preparation produced a significant IgG antibody response (P < 0.001) and were protected (83.3 %; P < 0.001) against lethal challenge with 36× LD50 of a virulent strain of L. interrogans serovar Copenhageni. A vaccine preparation based on demannosylated mLigANI (nmLigANI) elicited an immune response in hamsters, but did not afford protection. The production of mLigANI in bioreactor by P. pastoris yielded ~50 mg L(-1) of recombinant protein. P. pastoris is a potential platform for the production of leptospiral antigens on an industrial scale. The results demonstrate that LigANI secreted by P. pastoris on mannosylated form (mLigANI) protect hamsters as subunit vaccine of L. interrogans lethal infection.
Assuntos
Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Reatores Biológicos , Leptospira/química , Leptospirose/prevenção & controle , Proteínas Recombinantes/imunologia , Animais , Antígenos de Bactérias/genética , Antígenos de Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cricetinae , Feminino , Leptospira/genética , Leptospirose/imunologia , Pichia/genética , Pichia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análise de SobrevidaRESUMO
Senescent cell number increases with age in different tissues, leading to greater senescent cell load, proinflammatory stress, and tissue dysfunction. In the current study, we tested the efficacy of senolytic drugs to reduce ovarian senescence and improve fertility in reproductive age female mice. In the first experiment, 1-month-old C57BL/6 female mice were treated every other week with D + Q (n = 24) or placebo (n = 24). At 3 and 6 months of age, female mice were mated with untreated males to evaluate pregnancy rate and litter size. In the second experiment, 6-month-old C57BL/6 female mice were treated monthly with D + Q (n = 30), fisetin (n = 30), or placebo (n = 30). Females were treated once a month until 11 months of age, then they were mated with untreated males for 30 days to evaluate pregnancy rate and litter size. In the first experiment, D + Q treatment did not affect pregnancy rate (P = 0.68), litter size (P = 0.58), or ovarian reserve (P > 0.05). Lipofuscin staining was lower in females treated with D + Q (P = 0.04), but expression of senescence genes in ovaries was similar. In the second experiment, D + Q or fisetin treatment also did not affect pregnancy rate (P = 0.37), litter size (P = 0.20), or ovarian reserve (P > 0.05). Lipofuscin staining (P = 0.008) and macrophage infiltration (P = 0.002) was lower in fisetin treated females. Overall, treatment with D + Q or fisetin did not affect ovarian reserve or fertility but did decrease some senescence markers in the ovary.
Assuntos
Reserva Ovariana , Gravidez , Masculino , Camundongos , Feminino , Animais , Senoterapia , Lipofuscina , Camundongos Endogâmicos C57BL , FertilidadeRESUMO
Senescent cells have been linked to the pathogenesis of metabolic dysfunction-associated steatotic liver disease (MASLD). However, the effectiveness of senolytic drugs in reducing liver damage in mice with MASLD is not clear. Additionally, MASLD has been reported to adversely affect male reproductive function. Therefore, this study aimed to evaluate the protective effect of senolytic drugs on liver damage and fertility in male mice with MASLD. Three-month-old male mice were fed a standard diet (SD) or a choline-deficient western diet (WD) until 9 months of age. At 6 months of age mice were randomized within dietary treatment groups into senolytic (dasatinib + quercetin [D + Q]; fisetin [FIS]) or vehicle control treatment groups. We found that mice fed choline-deficient WD had liver damage characteristic of MASLD, with increased liver size, triglycerides accumulation, fibrosis, along increased liver cellular senescence and liver and systemic inflammation. Senolytics were not able to reduce liver damage, senescence and systemic inflammation, suggesting limited efficacy in controlling WD-induced liver damage. Sperm quality and fertility remained unchanged in mice developing MASLD or receiving senolytics. Our data suggest that liver damage and senescence in mice developing MASLD is not reversible by the use of senolytics. Additionally, neither MASLD nor senolytics affected fertility in male mice.
Assuntos
Fertilidade , Flavonóis , Quercetina , Senoterapia , Animais , Masculino , Camundongos , Fertilidade/efeitos dos fármacos , Quercetina/farmacologia , Senoterapia/farmacologia , Flavonóis/farmacologia , Fígado/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Senescência Celular/efeitos dos fármacos , Fígado Gorduroso/tratamento farmacológico , Fígado Gorduroso/metabolismo , Fígado Gorduroso/patologia , Dieta Ocidental/efeitos adversos , Progressão da Doença , Deficiência de Colina/complicações , Camundongos Endogâmicos C57BL , Modelos Animais de DoençasRESUMO
Introduction: Bladder cancer is a common neoplasia of the urinary tract that holds the highest cost of lifelong treatment per patient, highlighting the need for a continuous search for new therapies for the disease. Current bladder cancer models are either imperfect in their ability to translate results to clinical practice (mouse models), or rare and not inducible (canine models). Swine models are an attractive alternative to model the disease due to their similarities with humans on several levels. The Oncopig Cancer Model has been shown to develop tumors that closely resemble human tumors. However, urothelial carcinoma has not yet been studied in this platform. Methods: We aimed to develop novel Oncopig bladder cancer cell line (BCCL) and investigate whether these urothelial swine cells mimic human bladder cancer cell line (5637 and T24) treatment-responses to cisplatin, doxorubicin, and gemcitabine in vitro. Results: Results demonstrated consistent treatment responses between Oncopig and human cells in most concentrations tested (p>0.05). Overall, Oncopig cells were more predictive of T24 than 5637 cell therapeutic responses. Microarray analysis also demonstrated similar alterations in expression of apoptotic (GADD45B and TP53INP1) and cytoskeleton-related genes (ZMYM6 and RND1) following gemcitabine exposure between 5637 (human) and Oncopig BCCL cells, indicating apoptosis may be triggered through similar signaling pathways. Molecular docking results indicated that swine and humans had similar Dg values between the chemotherapeutics and their target proteins. Discussion: Taken together, these results suggest the Oncopig could be an attractive animal to model urothelial carcinoma due to similarities in in vitro therapeutic responses compared to human cells.
RESUMO
Calorie restriction (CR) (25-40%) is the most commonly studied strategy for curtailing age-related disease and has also been found to extend reproductive lifespan in female mice. However, the effects of mild CR (10%), which is sustainable, on ovarian aging has not yet been addressed. 17α-estradiol (17α-E2) is another intervention shown to positively modulate healthspan and lifespan in mice but its effects on female reproduction remain unclear. We evaluated the effects of mild CR (10%) and 17α-E2 treatment on ovarian reserve and female fertility over a 24-week period, and compared these effects with the more commonly employed 30% CR regimen. Both 10% and 30% CR elicited positive effects on the preservation of ovarian reserve, whereas 17α-E2 did not alter parameters associated with ovarian function. Following refeeding, both 10% and 30% increased fertility as evidenced by greater pregnancy rates. In aligned with the ovarian reserve data, 17α-E2 also failed to improve fertility. Collectively, these data indicate that 10% CR is effective in preserving ovarian function and fertility, while 17α-E2 does not appear to have therapeutic potential for delaying ovarian aging.
Assuntos
Reserva Ovariana , Animais , Restrição Calórica , Estradiol/farmacologia , Feminino , Fertilidade , Camundongos , Ovário , GravidezRESUMO
BACKGROUND: Leptospirosis, a zoonosis caused by Leptospira spp., is recognized as an emergent infectious disease. Due to the lack of adequate diagnostic tools, vaccines are an attractive intervention strategy. Recombinant proteins produced in Escherichia coli have demonstrated promising results, albeit with variable efficacy. Pichia pastoris is an alternative host with several advantages for the production of recombinant proteins. RESULTS: The vaccine candidates LigANI and LipL32 were cloned and expressed in P. pastoris as secreted proteins. Large-scale expression resulted in a yield of 276 mg/L for LigANI and 285 mg/L for LipL32. The recombinant proteins were glycosylated and were recognized by antibodies present in the sera of patients with severe leptospirosis. CONCLUSIONS: The expression of LigANI and LipL32 in P. pastoris resulted in a significant increase in yield compared to expression in E. coli. In addition, the proteins were secreted, allowing for easy purification, and retained the antigenic characteristics of the native proteins, demonstrating their potential application as subunit vaccine candidates.
Assuntos
Proteínas da Membrana Bacteriana Externa/genética , Proteínas de Bactérias/genética , Vacinas Bacterianas/genética , Leptospira/imunologia , Leptospirose/imunologia , Lipoproteínas/genética , Pichia/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Bactérias/imunologia , Proteínas de Bactérias/metabolismo , Vacinas Bacterianas/imunologia , Vacinas Bacterianas/metabolismo , Glicosilação , Humanos , Leptospira/enzimologia , Lipoproteínas/imunologia , Lipoproteínas/metabolismo , Pichia/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Vacinas de Subunidades Antigênicas/genética , Vacinas de Subunidades Antigênicas/imunologia , Vacinas de Subunidades Antigênicas/metabolismoRESUMO
BACKGROUND: Medicinal plants are an important source to identify new active pharmaceutical compounds. Traditionally, the sap of Euphorbia umbellata is widely used to treat cancer and inflammatory conditions. These effects have been attributed to the presence of terpenes and phenolic compounds in the extracts of this plant. Euphol, a tetracyclic triterpene alcohol, is one of the major compounds present in Euphorbia species, and some biological activities have been attributed to this compound. PURPOSE: This study aimed to evaluate the in vitro cytotoxicity of euphol against Jurkat, HL-60, K-562, B16F10, and HRT-18 cells lines, as well as the biological stability, distribution, metabolism properties in vitro, and the determination of the concentration of euphol in the plasma and liver of rats. METHODS: The MTT reduction assay was used to evaluate the cytotoxicity of euphol against cancer cell lines, and the selectivity index, the morphology and cell cycle assays to evaluate the death mechanisms in K-562 and B16F10 lineages. UHPLC-MS was applied for the in vivo evaluation of the concentration of euphol in plasma and liver, and in vitro metabolic stability in human liver microsomes and S9 fraction, plasma protein binding, and stability in simulated gastric and intestinal fluids assays. CONCLUSIONS: This study demonstrated that euphol exhibited cytotoxic effects against a variety of cancer cells lines, selectivity against leukemia and possibly, the mechanism involved is apoptosis. The evaluation of stability, distribution, and metabolism properties showed that euphol was unstable in gastric and intestinal fluids, presenting moderate plasma protein binding with two hours elimination half-life and possible phase II liver metabolism. All the results suggested that further studies could be developed to prove the viability of euphol as an anticancer agent.
Assuntos
Euphorbia/química , Lanosterol/análogos & derivados , Látex/química , Animais , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Humanos , Células Jurkat , Lanosterol/farmacologia , Extratos Vegetais/farmacologia , Plantas Medicinais/química , RatosRESUMO
Toward developing an effective vaccine capable of conferring heterologous protection, the putative lipoprotein LemA, which presents an M3 epitope similar to that of Listeria, was evaluated as a vaccine candidate in the hamster model of leptospirosis. LemA is conserved (>70% pairwise identity) among the pathogenic Leptospira spp., indicating its potential in stimulating a cross-protective immune response. Using different vaccination strategies, including prime-boost, DNA vaccine, and a subunit preparation, recombinant LemA conferred different levels of protection in hamsters. Significant protection against mortality was observed for the prime-boost and the DNA vaccine strategies, which showed 87.5% (P < 0.01) and 62.5% (P < 0.05) efficacy, respectively. Although the subunit vaccine preparation protected 50.0% of immunized hamsters, the level of protection was not significant. None of the hamsters in the control groups survived challenge with a virulent strain of Leptospira interrogans serogroup Icterohaemorrhagiae. Characterization of the immune response found that the strongest antibody response was stimulated by the subunit vaccine preparation, followed by the prime-boost strategy. The DNA vaccine failed to elicit an antibody response in immunized hamsters.
Assuntos
Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Leptospira interrogans serovar icterohaemorrhagiae/imunologia , Leptospirose/imunologia , Fatores de Transcrição/imunologia , Animais , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/administração & dosagem , Cricetinae , Modelos Animais de Doenças , Imunização Secundária , Leptospirose/prevenção & controle , Fatores de Transcrição/administração & dosagem , Vacinação , Vacinas de DNA/imunologia , Vacinas de Subunidades Antigênicas/imunologia , Vacinas Sintéticas/imunologiaRESUMO
Leptospirosis is a zoonotic disease caused by pathogenic spirochetes of theLeptospira genus. Vaccination with bacterins has severe limitations. Here, we evaluated the N-terminal region of the leptospiral immunoglobulin-like B protein (LigBrep) as a vaccine candidate against leptospirosis using immunisation strategies based on DNA prime-protein boost, DNA vaccine, and subunit vaccine. Upon challenge with a virulent strain ofLeptospira interrogans, the prime-boost and DNA vaccine approaches induced significant protection in hamsters, as well as a specific IgG antibody response and sterilising immunity. Although vaccination with recombinant fragment of LigBrep also produced a strong antibody response, it was not immunoprotective. These results highlight the potential of LigBrep as a candidate antigen for an effective vaccine against leptospirosis and emphasise the use of the DNA prime-protein boost as an important strategy for vaccine development.
Assuntos
Animais , Cricetinae , Feminino , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/imunologia , Vacinas Bacterianas/imunologia , Leptospira/imunologia , Leptospirose/prevenção & controle , Vacinação/métodos , Adjuvantes Imunológicos , Biópsia , Chlorocebus aethiops , Sequência Conservada , Ensaio de Imunoadsorção Enzimática , Imunidade Humoral/imunologia , Imunoglobulina A/genética , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulinas/genética , Imunoglobulinas/imunologia , Rim/patologia , Leptospirose/imunologia , Pulmão/patologia , Mesocricetus , Análise de Sobrevida , Células Vero , Vacinas de DNA/imunologia , Vacinas Sintéticas/imunologia , Vacinas Sintéticas/microbiologiaRESUMO
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.