RESUMO
Despite the widespread use of silver nanoparticles (AgNPs) in different fields and the amount of investigations available, to date, there are many contradictory results on their potential toxicity. In the present study, extensively characterized 20-nm AgNPs were investigated using optimized protocols and standardized methods to test several toxicological endpoints in different cell lines. The agglomeration/aggregation state of AgNPs in culture media was measured by dynamic light scattering (DLS). DNA and chromosomal damage on BEAS-2B and RAW 264.7 cells were evaluated by comet and micronucleus assays, while oxidative DNA damage by modified comet assay and 8-oxodG/8-oxodA detection. We also investigated immunotoxicity and immunomodulation by cytokine release and NO production in RAW 264.7 and MH-S cells, with or without lipopolysaccharide (LPS) stimulus. Transmission electron microscope (TEM) analysis was used to analyze cellular uptake of AgNPs. Our results indicate different values of AgNPs hydrodynamic diameter depending on the medium, some genotoxic effect just on BEAS-2B and no or slight effects on function of RAW 264.7 and MH-S in absence or presence of LPS stimulus. This study highlights the relevance of using optimized protocols and multiple endpoints to analyze the potential toxicity of AgNPs and to obtain reliable and comparable results.
Assuntos
Técnicas In Vitro/métodos , Nanopartículas Metálicas/toxicidade , Prata/toxicidade , Testes de Toxicidade/métodos , Linhagem Celular , Ensaio Cometa , Testes para MicronúcleosRESUMO
The European Union (EU) continuously takes ensuring the safe use of manufactured nanomaterials (MNMs) in consumer products into consideration. The application of a common approach for testing MNMs, including the use of optimized protocols and methods' selection, becomes increasingly important to obtain reliable and comparable results supporting the regulatory framework. In the present study, we tested four representative MNMs, two titanium dioxides (NM100 and NM101) and two silicon dioxides (NM200 and NM203), using the EU FP7-NANoREG approach, starting from suspension and dispersion preparations, through to their characterization and final evaluation of biological effects. MNM dispersions were prepared following a refined NANOGENOTOX protocol and characterized by dynamic light scattering (DLS) in water/bovine serum albumin and in media used for in vitro testing. Potential genotoxic effects were evaluated on human bronchial BEAS-2B cells using micronucleus and Comet assays, and pro-inflammatory effects by cytokines release. Murine macrophages RAW 264.7 were used to detect potential innate immune responses using two functional endpoints (pro-inflammatory cytokines and nitric oxide [NO] production). The interaction of MNMs with RAW 264.7 cells was studied by electron microscopy. No chromosomal damage and slight DNA damage and an oxidative effect, depending on MNMs, were observed in bronchial cells. In murine macrophages, the four MNMs directly induced tumor necrosis factor α or interleukin 6 secretion, although at very low levels; lipopolysaccharide-induced NO production was significantly decreased by the titania and one silica MNM. The application of this approach for the evaluation of MNM biological effects could be useful for both regulators and industries.
Assuntos
Política de Saúde/legislação & jurisprudência , Imunidade Inata/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Nanotecnologia/legislação & jurisprudência , Dióxido de Silício/toxicidade , Titânio/toxicidade , Testes de Toxicidade , Animais , Brônquios/efeitos dos fármacos , Brônquios/imunologia , Brônquios/metabolismo , Brônquios/patologia , Sobrevivência Celular/efeitos dos fármacos , Ensaio Cometa , Qualidade de Produtos para o Consumidor/legislação & jurisprudência , Citocinas/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Europa (Continente) , União Europeia , Regulamentação Governamental , Humanos , Mediadores da Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Micronúcleos com Defeito Cromossômico/induzido quimicamente , Testes para Micronúcleos , Formulação de Políticas , Células RAW 264.7 , Medição de RiscoRESUMO
An early dialogue between nanomedicine developers and regulatory authorities are of utmost importance to anticipate quality and safety requirements for these innovative health products. In order to stimulate interactions between the various communities involved in a translation of nanomedicines to clinical applications, the European Commission's Joint Research Centre hosted a workshop titled "Bridging communities in the field of Nanomedicine" in Ispra/Italy on the 27th -28th September 2017. Experts from regulatory bodies, research institutions and industry came together to discuss the next generation of nanomedicines and their needs to obtain regulatory approval. The workshop participants came up with recommendations highlighting methodological gaps that should be addressed in ongoing projects addressing the regulatory science of nanomedicines. In addition, individual opinions of experts relevant to progress of the regulatory science in the field of nanomedicine were summarised in the format of a survey.
Assuntos
Nanomedicina , Tomada de Decisões , Sistemas de Apoio a Decisões Clínicas , Humanos , Inquéritos e QuestionáriosRESUMO
In previous studies it has been demonstrated that the plant alkaloid voacamine (1), used at noncytotoxic concentrations, enhanced the cytotoxicity of doxorubicin and exerted a chemosensitizing effect on cultured multidrug-resistant (MDR) U-2 OS-DX osteosarcoma cells. The in vitro investigations reported herein gave the following results: (i) the chemosensitizing effect of 1, in terms of drug accumulation and cell survival, was confirmed using SAOS-2-DX cells, another MDR osteosarcoma cell line; (ii) compound 1 enhanced the cytotoxic effect of doxorubicin also on the melanoma cell line Me30966, intrinsically drug resistant and P-glycoprotein-negative; (iii) at the concentrations used to sensitize tumor cells, 1 was not cytotoxic to normal cells (human fibroblasts). These findings suggest possible applications of voacamine (1) in integrative oncologic therapies against resistant tumors.
Assuntos
Alcaloides/farmacologia , Neoplasias Ósseas/tratamento farmacológico , Doxorrubicina/farmacologia , Fibroblastos/metabolismo , Ibogaína/análogos & derivados , Melanoma/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Alcaloides/química , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Imunofluorescência , Humanos , Ibogaína/química , Ibogaína/farmacologia , Estrutura MolecularAssuntos
Alérgenos/imunologia , Antígenos de Plantas/imunologia , Hipersensibilidade/imunologia , Parietaria/imunologia , Proteínas de Plantas/imunologia , Plantas Geneticamente Modificadas/imunologia , Alérgenos/genética , Animais , Antígenos de Plantas/genética , Modelos Animais de Doenças , Humanos , Camundongos , Parietaria/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas/genéticaRESUMO
2,2',4,4'-tetra-bromodiphenyl ether (BDE-47) is widespread in the environment and biological samples. Its association with health risks is an increasing concern, yet information on BDE-47 immunotoxicity remains limited. This study investigated the impact of BDE-47 on innate and adaptive immune responses through in vitro and in vivo approaches. BDE-47's capacity to directly induce cell responses and modulate responses induced by known stimuli was studied in vitro using the RAW 264.7 murine macrophage cell line and spleen-derived lymphocytes, and in vivo using keyhole limpet hemocyanin (KLH)-immunized BALB/c mice orally administered (28 d) at dose levels (7.5, 15.0 and 30 mg/kg/bw/d) derived from relevant toxicokinetic data from rodent models. RAW 264.7 cells stimulated with lipopolysaccharide (LPS) and exposed to BDE-47 exhibited unchanged cell viability but decreased release of interleukin (IL)-6. Primary splenocytes from naïve mice stimulated with anti-CD3/anti-CD28 antibodies and exposed to BDE-47 showed a significant decrease of IL-17 A and IFNγ production. In vivo data showed that BDE-47 significantly reduced the KLH-specific antibody response. A generally decreasing trend of IFNγ, IL-10 and IL-5 production was observed after in vitro antigen-specific restimulation of spleen cells. Histopathological effects on liver, spleen, small intestine and thyroid were detected at the highest dose in the absence of general toxicity. In addition, the expression of Mm_mir155 and Mm_let7a was induced in livers of exposed mice. The data obtained in this study suggest that exposure to BDE-47 may perturb innate and adaptive immune responses, thus possibly decreasing resistance to bacterial and viral infections.
Assuntos
Imunidade , Interleucina-6 , Camundongos , Animais , Modelos Animais de Doenças , Camundongos Endogâmicos BALB C , HemocianinasRESUMO
BACKGROUND: Shellfish allergy is one of the major causes of life-threatening allergic reactions to food. The shrimp species Pandalus borealis is the commercially most important coldwater shrimp species, and its protein extract is commonly used in shrimp allergy diagnostics. However, the DNA sequence of its major allergen, tropomyosin, designated Pan b 1, was not previously described. Our aim was to identify the cDNA sequence of Pan b 1 and to generate a recombinant protein with similar structure and allergenicity as the natural protein. METHODS: P. borealis shrimps were caught in the Oslofjord (Norway). cDNA from Pan b 1 was generated, an N-terminal histidine tag was added, and the protein was expressed in Escherichia coli. The recombinant Pan b 1 was characterized by structural and IgE-binding studies and investigated further with basophil activation tests (BATs) and skin prick tests (SPTs) on Norwegian shrimp-allergic individuals. RESULTS: The open reading frame encoded 284 amino acids that shared 97-100% identity with other shrimp tropomyosins. Mass spectroscopy of natural Pan b 1 confirmed the protein's molecular mass and indicated the absence of posttranslational modifications. Circular dichroism spectroscopy revealed virtually identical spectra between recombinant and natural Pan b 1, which together with native PAGE and size exclusion chromatography results indicated a similar structure. Furthermore, immunoblot and ELISA studies as well as BATs and SPTs showed equivalent results of recombinant and natural Pan b 1. CONCLUSION: A recombinant tropomyosin from P. borealis was generated that can be used in diagnostics and further studies on tropomyosin allergenicity and specific immunotherapy.
Assuntos
Alérgenos/imunologia , Proteínas de Artrópodes/imunologia , Hipersensibilidade Alimentar/imunologia , Pandalidae/imunologia , Proteínas Recombinantes/imunologia , Tropomiosina/imunologia , Adulto , Alérgenos/química , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/química , Teste de Degranulação de Basófilos , Células Cultivadas , Evolução Molecular , Feminino , Humanos , Imunoglobulina E/metabolismo , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Pandalidae/metabolismo , Ligação Proteica , Conformação Proteica , Proteínas Recombinantes/química , Frutos do Mar/efeitos adversos , Tropomiosina/metabolismoRESUMO
Synthetic amorphous silica (SAS) consists of agglomerates and aggregates of primary particles in the nanorange (<100 nm) and it is the E551 authorized food additive. The potential risks for human health associated to dietary exposure to SAS are not completely assessed; in particular, data on male and female reproductive systems are lacking. A 90-day oral toxicity study with pyrogenic SAS nanomaterial NM-203 was carried out on the basis of the OECD test guideline 408 in the frame of the NANoREG project. Adult Sprague-Dawley rats of both sexes were orally treated for 90 days with 0, 2, 5, 10, 20 and 50 mg SAS/kg bw per day. Dose levels were selected to be as close as possible to the expected human exposure to food additive E551. The present paper provides specific information on potential effects on male and female reproductive systems, through the evaluation of serum biomarkers, sperm count, histopathological analysis of testis, epididymis, ovary and uterus and real-time PCR on uterus; potential genotoxic alterations were evaluated by comet assay on testis, sperm and ovary. NM-203 did not induce histophatological and genotoxic effects in male reproductive system. In female rats, ovary is not target of NM-203 and only tissue-specific effects on uterus were recorded up to 10 mg/kg bw per day. To our best knowledge, this is the first study providing data on male and female reproductive systems after long-term, repeated oral exposure at dose levels close to dietary human exposure, which identifies a limited concern only for female reproductive health.
Assuntos
Dióxido de Silício/toxicidade , Administração Oral , Animais , Ensaio Cometa , Estradiol/sangue , Feminino , Expressão Gênica/efeitos dos fármacos , Genitália/efeitos dos fármacos , Genitália/metabolismo , Antígeno Ki-67/metabolismo , Masculino , Ratos Sprague-Dawley , Contagem de Espermatozoides , Testosterona/sangue , Testes de Toxicidade SubcrônicaRESUMO
Food additive E551 consists of synthetic amorphous silica (SAS), comprising agglomerates and aggregates of primary particles in the nanorange (<100 nm), which potential nanospecific risks for humans associated to dietary exposure are not yet completely assessed. In NANoREG project, aim of the study was to identify potential hazards of pyrogenic SAS nanomaterial NM-203 by a 90-day oral toxicity study (OECD test guideline 408). Adult Sprague-Dawley rats of both sexes were orally treated with 0, 2, 5, 10, 20 and 50 mg SAS/kg bw per day; dose levels were selected to be as close as possible to E551 dietary exposure. Several endpoints were investigated, the whole integrative study is presented here along with the results of dispersion characterization, tissue distribution, general toxicity, blood/serum biomarkers, histopathological and immunotoxicity endpoints. No mortality, general toxicity and limited deposition in target tissues were observed. NM-203 affected liver and spleen in both sexes. Proposed NOAEL 5 mg/kg bw per day in male rats for enlarged sinusoids in liver. In female rats, TSH and creatinine levels were affected, proposed LOAEL 2 mg/kg bw per day. Overall, these data provide new insight for a comprehensive risk assessment of SAS exposure by the oral route.
Assuntos
Aditivos Alimentares/toxicidade , Nanoestruturas/toxicidade , Dióxido de Silício/toxicidade , Administração Oral , Animais , Biomarcadores/sangue , Feminino , Aditivos Alimentares/administração & dosagem , Fígado/patologia , Masculino , Nanoestruturas/administração & dosagem , Nível de Efeito Adverso não Observado , Ratos Sprague-Dawley , Medição de Risco , Silício/análise , Dióxido de Silício/administração & dosagemRESUMO
Appropriate murine models of shrimp tropomyosin (ST) allergy would be useful in investigating the mechanisms underlying food allergy in human subjects, as well as for the pre-clinical evaluation of efficacy and safety of novel therapeutic approaches. These models should mimic immune and clinical features of human disease, including anaphylactic response. We sensitized C3H/HeJ mice by the oral route with purified ST using cholera toxin (CT) as adjuvant. ST-specific IgE, IgG1, IgG2a and IgA responses were evaluated by ELISA. Spleen cell proliferation and cytokine production by allergen-specific activation were assessed. Jejunum and colon fragments were collected to evaluate the local expression of cytokine genes by PCR. Local and systemic anaphylactic reactions induced by oral ST challenge were scored according to symptoms observed. Faecal samples were collected to assess local IgA production and histamine levels. Oral sensitization with ST plus CT induced in mice significant levels of serum IgE and IgG1 and faecal IgA. ST-specific cell proliferation and IL-4, IL-13 and IFN-gamma cytokine production were induced in the spleen. After oral challenge, 100% of mice had anaphylactic symptoms while no symptoms were observed in challenged naive mice. Faecal histamine content after ST challenge appeared significantly increased in sensitized mice when compared with that observed in pre-immune mice. Jejunum mRNA expression of T(h)2 cytokines was up-regulated by ST sensitization. These results support the importance of the oral way of sensitization and of the in-depth characterization of the anaphylactic response for the development of a suitable in vivo model of food allergy.
Assuntos
Hipersensibilidade Alimentar/imunologia , Imunoglobulina E/imunologia , Ativação Linfocitária/imunologia , Proteínas/imunologia , Células Th2/metabolismo , Administração Oral , Alérgenos , Anafilaxia/sangue , Anafilaxia/etiologia , Animais , Proteínas de Artrópodes , Dessensibilização Imunológica , Modelos Animais de Doenças , Epitopos , Hipersensibilidade Alimentar/terapia , Liberação de Histamina/efeitos dos fármacos , Liberação de Histamina/imunologia , Imunoglobulina E/sangue , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C3H , Proteínas/administração & dosagem , Frutos do Mar/efeitos adversos , Células Th2/citologia , Células Th2/imunologiaRESUMO
BACKGROUND: The immunological mechanisms responsible for the immunomodulatory and anti-allergic effects of probiotic bacteria are still poorly defined. The combined effects of mixtures of different species of probiotic bacteria have been explored only in part. The present study describes the immunomodulatory activity of the VSL#3 probiotic preparation in in vitro and in vivo systems. METHODS: The activation and cytokine production by in vitro probiotic-stimulated bone-marrow dendritic cells (BM-DCs) and spleen cells isolated from naïve or Par j 1-sensitized mice were investigated. Mice were intranasally administered a sonicate preparation of VSL#3 before immunization with rPar j 1. Serum antibody levels and cytokine expression in the lung were determined. RESULTS: Both live and sonicated VSL#3 preparations induced maturation and cytokine production by BM-DCs. Cytokine production by spleen cells from naïve or Par j 1-sensitized mice was modulated by the probiotic preparations towards a Treg/Th0 profile, characterized by increased IL-10 and IFN-gamma production. In vivo prophylactic treatment with VSL#3 induced a significant reduction of serum specific IgG1. At lung level, VSL#3 pre-treatment remarkably reduced IL-13 and IL-4 mRNA expression and increased IL-10 expression. CONCLUSIONS: The VSL#3 preparations have not only the capacity to bias primary immune responses towards a Treg/Th0-type profile, but also to modify in the same way the functional characteristics of established in vitro Th2 responses. In vivo studies on a mouse model of Par j 1 sensitization indicate that the prophylactic intranasal treatment with probiotic bacteria is able to modulate the development of Th2-biased responses.
Assuntos
Alérgenos/imunologia , Imunidade Celular/imunologia , Probióticos/farmacologia , Células Th2/imunologia , Animais , Formação de Anticorpos/efeitos dos fármacos , Formação de Anticorpos/imunologia , Antígenos CD/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Feminino , Fator de Transcrição GATA3/genética , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/imunologia , Imunidade Celular/efeitos dos fármacos , Imunoglobulinas/sangue , Interferon gama/genética , Interferon gama/metabolismo , Interleucina-10/genética , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Interleucina-13/genética , Interleucina-4/genética , Interleucina-5/metabolismo , Lipopolissacarídeos/farmacologia , Pulmão/imunologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Proteínas de Plantas/imunologia , Probióticos/administração & dosagem , Baço/citologia , Proteínas com Domínio T/genética , Linfócitos T/imunologia , Linfócitos T/metabolismo , Células Th2/metabolismo , VacinaçãoRESUMO
The aim of the study was to assess the symptoms prevalence of allergic diseases in a population of 11-15 yr old schoolchildren, to evaluate the associations between asthma and other symptoms and identify risk factors for asthma, rhinitis and eczema syndromes. A sample of 481 students was studied using an International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire. Prevalence of different kind of self-reported symptoms was calculated. Using a logistic regression approach, we tried to identify risk factors for three syndromes - rhinitis, eczema and asthma. The highest and the lowest prevalence rates of self-reported symptoms were recorded for rhinitis (43.6%) and for eczema (8.1%), respectively. The prevalence of asthma was 15.7%. Univariate analysis showed a mutual association between wheeze and rhinitis symptoms. Multivariate logistic regression model for eczema syndrome revealed female gender as a significant risk factor. The polytomic logistic multivariate regression revealed female gender and family history of allergy as significant risk factors for rhinitis syndrome only, and maternal smoking and familial allergy for rhinitis and asthma together. In particular, familial allergy yields a 400% higher chance of developing asthma and rhinitis together. The synergistic effect of familial allergy on rhinitis and asthma syndromes suggests the implementation of preventive measures in children with family history of these diseases.
Assuntos
Asma/epidemiologia , Eczema/epidemiologia , Hipersensibilidade/epidemiologia , Rinite/epidemiologia , Adolescente , Criança , Estudos Transversais , Eczema/fisiopatologia , Feminino , Humanos , Hipersensibilidade/fisiopatologia , Itália/epidemiologia , Modelos Logísticos , Masculino , Prevalência , Rinite/fisiopatologia , Fatores de Risco , Inquéritos e QuestionáriosRESUMO
Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants that are added to numerous products to prevent accidental fires. PBDEs are present in the environment and they bio-accumulate in human and animal tissues. Recently, their presence has been correlated to several pathologies but little is known about their effect on the human innate immune system activity. In this study we investigated the effect of the congener 2,2',4,4'-Tetrabromodiphenyl ether (PBDE-47) on the functional activity of the THP-1 human macrophages cell line and on ex vivo freshly isolated human basophils. Cytotoxicity and genotoxicity studies showed that PBDE-47 was able to induce toxic effects on the THP-1â¯cell line viability at concentrations ≥25⯵M. Immune function of THP-1 was studied after stimulation with bacterial lipopolysaccharide (LPS) and PBDE-47 exposure at concentrations granting macrophage viability. Two dimensional electrophoresis showed modification of the proteome in the 3⯵M PBDE-47 treated sample and Real Time PCR and ELISA demonstrated a statistically significant reduction in the expression of IL-1ß, IL-6 and TNF-α cytokines. Furthermore, PBDE-47 was able to perturbate genes involved in cell motility upregulating CDH-1 and downregulating MMP-12 expressions. Finally, basophil activation assay showed reduced CD63 activation in PBDE-47 treated samples. In conclusion, our study demonstrated that PBDE-47 may perturb the activities of cells involved in innate immunity dampening the expression of macrophage pro-inflammatory cytokines (IL-1ß, IL-6 and TNF-α) and genes involved in cell motility (MMP-12 and E-cadherin) and interfering with basophil activation suggesting that this compound can impair innate immune response.
Assuntos
Éteres Difenil Halogenados/toxicidade , Imunidade Inata/efeitos dos fármacos , Animais , Basófilos/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Poluentes Ambientais/farmacologia , Éteres Difenil Halogenados/farmacologia , Humanos , Macrófagos/efeitos dos fármacos , Células THP-1RESUMO
Probiotic bacteria as modulators of the immune response have been intensively studied in reducing the risk of immune-mediated diseases, including atopic diseases. Results from in vitro studies demonstrated that probiotics may modify the polarization of immune cells, supporting potential therapeutic effects in atopic diseases. Several clinical studies have been designed to explore the effective role of probiotics in the modulation of allergic diseases. The results of these studies, although promising, are not conclusive yet and are considered insufficient to recommend probiotics as a part of standard therapy in any allergic conditions. In vivo studies on animal models can provide useful information on the immunologic mechanisms responsible for the potential antiallergic effects of probiotic bacteria. The immunomodulatory activity of the probiotic mixture VSL#3 has been studied in the mouse models of allergic sensitization and anaphylaxis developed in our laboratory with inhalant and food allergens, according to a prophylactic setting by the intranasal route (inhalant allergy model) or a therapeutic setting by the oral route (food allergy model). Intranasally delivered probiotic bacteria prevented the development of Parietaria major allergen-specific response, by down-regulating T helper cell 2 responses at the local and systemic level. Oral therapeutic treatment was able to reduce both systemic and local anaphylactic symptoms induced by oral challenge with the sensitizing allergen Shrimp Tropomyosin. The induction of protective immune responses at the sites of allergen exposure linked to counterregulatory local and systemic immune responses by mucosal delivery of probiotic bacteria mixtures might become an effective strategy in the prevention and therapy of allergic diseases.
Assuntos
Alérgenos/imunologia , Modelos Animais de Doenças , Hipersensibilidade Alimentar , Hipersensibilidade Imediata , Probióticos , Alérgenos/efeitos adversos , Animais , Bifidobacterium/classificação , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/prevenção & controle , Hipersensibilidade Alimentar/terapia , Humanos , Hipersensibilidade Imediata/etiologia , Hipersensibilidade Imediata/imunologia , Hipersensibilidade Imediata/prevenção & controle , Hipersensibilidade Imediata/terapia , Lactobacillus/classificação , Camundongos , Parietaria/imunologia , Probióticos/administração & dosagem , Probióticos/efeitos adversos , Probióticos/uso terapêutico , Streptococcus thermophilus , Resultado do TratamentoRESUMO
Insects and insect-derived materials have been implicated as a risk factor for sensitization and subsequent elicitation of allergic rhinitis and allergic bronchial asthma. During the last decades, insects other than those known as allergenic, were investigated for their potential role in inducing and triggering an IgE immune response. Among these, the silverfish, an insect belonging to the Thysanura order, appeared to be of particular interest. Silverfish (Lepisma saccharina) is the most primitive living insect, and represents a descendent of the ancestral wingless insects. They are 3-12 mm long, have three tail feelers and are covered with shiny scales. They shun light and need a humid environment and their diet consists of carbohydrate materials such as paper and book-binding glue, crumbs of bread and flour. Because of these features, silverfish finds an optimal habitat both in dwellings and workplaces and in spite of its antiquity, silverfish has succeeded in exploiting the new opportunity created by man. Although its importance significantly increased when it has been demonstrated that house dust contains significant silverfish levels even in houses where the inhabitants were unaware of its presence, no silverfish extract for diagnosis of allergic diseases is commercially available yet. Identification of optimal extraction conditions and characterization of allergenic extracts are the first steps to obtain an effective allergen preparation suitable for diagnosis and therapy, and will be useful as a reference preparation for assessing silverfish exposure in different indoor environments. It has been cloned and characterized a silverfish tropomyosin, named Lep s 1, which represents the first allergen identified in silverfish extract and can be regarded as a molecule cross-reactive among inhalant and edible invertebrates allergenic sources. rLep s 1 displayed biological activity, suggesting that it could be regarded as a useful tool to study the role of silverfish tropomyosin in the sensitization to invertebrate allergic sources.
Assuntos
Alérgenos/imunologia , Alérgenos/metabolismo , Insetos/imunologia , Insetos/metabolismo , Animais , Clonagem Molecular , Reações Cruzadas , Humanos , Hipersensibilidade/imunologia , Hipersensibilidade/metabolismo , Insetos/química , Insetos/genética , Tropomiosina/genéticaRESUMO
Allergen-specific immunotherapy was introduced in clinical settings more than 100 years ago. It remains the only curative approach to treating allergic disorders that ameliorates symptoms, reduces medication costs, and blocks the onset of new sensitizations. Despite this clinical evidence and knowledge of some immunological mechanisms, there remain some open questions regarding the safety and efficacy of this treatment. This suggests the need for novel therapeutic approaches that attempt to reduce the dose and frequency of treatment administration, improving patient compliance, and reducing costs. In this context, the use of novel adjuvants has been proposed and, in recent years, biomedical applications using nanoparticles have been exploited in the attempt to find formulations with improved stability, bioavailability, favorable biodistribution profiles, and the capability of targeting specific cell populations. In this article, we review some of the most relevant regulatory aspects and challenges concerning nanoparticle-based formulations with immunomodulatory potential, their related immunosafety issues, and the nature of the nanoparticles most widely employed in the allergy field. Furthermore, we report in vitro and in vivo data published using allergen/nanoparticle systems, discuss their impact on the immune system in terms of immunomodulatory activity and the reduction of side effects, and show that this strategy is a novel and promising tool for the development of allergy vaccines.
Assuntos
Alérgenos/farmacologia , Dessensibilização Imunológica/métodos , Nanopartículas/química , Adjuvantes Imunológicos/farmacologia , Alérgenos/química , Alérgenos/imunologia , Animais , Disponibilidade Biológica , Humanos , Nanopartículas/uso terapêutico , Nanopartículas/toxicidade , Distribuição TecidualRESUMO
BACKGROUND: Anisakis simplex is the only fishery-product associated parasite causing clinical allergic responses in humans so far. However, other anisakids, due to the presence of shared or own allergens, could also lead to allergic reactions after sensitization. The aim of this study was to determine if Pseudoterranova decipiens belonging to the family Anisakidae has allergenic activity and is able to induce sensitization after oral administration in a murine (BALB/c mice) model. RESULTS: The ingestion of A. pegreffii proteins by BALB/c mice, which had been previously sensitized by intraperitoneal inoculation with the corresponding live L3 larvae, triggers signs of allergy within 60 min, whereas P. decipiens did to a lesser extent. Beside symptoms, allergic reactions were furtherly supported by the presence of histamine in sera of sensitized mice. Specific IgG1 and IgE responses were detected in sera of all sensitized mice from week four. Specific IgG2a response was detected in sera from mice sensitized to P. decipiens. After polyclonal or specific activation with anti-CD3/anti-CD28 or antigens, respectively, splenocytes from mice infected i.p. with A. pegreffii or P. decipiens larvae showed significantly higher production of IL-10 than naïve mice. After stimulation with specific antigens, significantly higher IL-5 and IL-13 amounts were produced by specific antigen stimulated splenocytes than by the naïve cells; only P. decipiens proteins induced IFN-É£. CONCLUSIONS: The overall results suggest that infection with P. decipiens can sensitize mice to react to subsequent oral challenge with anisakid proteins, as described for A. simplex (sensu stricto) and A. pegreffii infections. The results show that anisakid proteins induce a dominant Th2 response, although P. decipiens could also induce a mixed type 1/type 2 pattern.
Assuntos
Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/imunologia , Ascaridoidea/imunologia , Histamina/sangue , Imunidade Humoral , Animais , Anisaquíase/parasitologia , Anisakis/imunologia , Feminino , Humanos , Imunização , Interleucinas/imunologia , Larva , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Allergen specific immunotherapy has been introduced in the clinic more than 100 years ago showing effectiveness and, so far, it represents the only curative approach to treat allergic disorders ameliorating the symptoms, reducing the medication costs and blocking the onset of new sensitizations. However, some questions are still open regarding to the safety of the treatment and the need to reduce the dose and time of administration to improve the compliance of the patients. All preparations that are currently available may trigger side effects. For these reasons, new formulations and route of administration have been exploited demonstrating that such products presented improved efficacy and safety. Nanotechnology for biomedical applications offers many advantages, such as improved stability and bioavailability, favourable biodistribution profiles and targeting to specific cell populations whose impact on the immune system has been evaluated in animal systems. Nanoparticles interact with the immune system, and the final outcome of this interaction depends on their physico-chemical characteristics. Concerns can be raised when immunotoxic effect are induced, resulting in inflammatory dangerous responses or in the reduction of the normal defensive activity of the immune system. In this paper, we will review the most relevant data about the synthesis of allergen/nanoparticles systems and will discuss their impact on the immune system in terms of immunomodulatory activity and immunotoxicity risk assessment.
Assuntos
Alérgenos/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Alérgenos/uso terapêutico , Disponibilidade Biológica , Portadores de Fármacos/administração & dosagem , Estabilidade de Medicamentos , Humanos , Imunoterapia/métodosRESUMO
SCOPE: Among food allergies, peanut allergy is frequently associated with severe anaphylactic reactions. In the need for safe and effective therapeutic strategies, probiotics may be considered on the basis of their immunomodulatory properties. The aim of the present study was to investigate the immunological mediators involved in the effects of probiotic VSL#3 oral supplementation on Th2 inflammation and anaphylaxis in a mouse model of peanut allergy. METHODS AND RESULTS: VSL#3 supplementation to peanut-sensitized mice was effective in ameliorating anaphylaxis and Th2-mediated inflammation, by promoting regulatory responses in the jejunum mucosa and in the mesenteric lymph node, as evaluated by ELISA, real-time PCR, histologic, and immunohistochemical analysis. Probiotic-induced TGF-ß mediates its protective effects through the induction of regulatory T cells expressing FOXP3 and/or latency-associated peptide, as proven by in vivo blockade of TGF-ß in VSL#3-treated mice with a neutralizing monoclonal antibody one day before challenge. CONCLUSION: TGF-ß, induced in the gut by VSL#3 supplementation, is capable of reducing the Th2 inflammation associated with food anaphylaxis in a mouse model of peanut sensitization. TGF-ß acts through the induction/maintenance of regulatory T cells expressing FOXP3 and/or latency-associated peptide. Probiotics supplementation may represent an effective and safe strategy for treating food allergies in adult population.
Assuntos
Hipersensibilidade a Amendoim/tratamento farmacológico , Probióticos/farmacologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/metabolismo , Administração Oral , Anafilaxia/tratamento farmacológico , Animais , Modelos Animais de Doenças , Feminino , Hipersensibilidade Alimentar/tratamento farmacológico , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/metabolismo , Fatores de Transcrição Forkhead/imunologia , Fatores de Transcrição Forkhead/metabolismo , Inflamação/tratamento farmacológico , Inflamação/imunologia , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/imunologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Hipersensibilidade a Amendoim/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/metabolismo , Fator de Crescimento Transformador beta/imunologiaRESUMO
Exposure to indoor allergens can occur both at home and in public places such as schools and workplaces. To investigate and compare the presence of indoor allergens in different kind of environments (schools, offices and homes), dust samples were collected from furniture, desks, mattresses and floors with a standardized procedure. Samples were analyzed for Der p 1, Der f 1, Mite group 2 (mites) and Fel d 1(cat) by monoclonal antibody ELISA assay. Mite allergens were detected with low frequencies in schools and workplaces and with high frequency in homes. Fel d 1 was found with high frequency in every examined environment. Homes rather than public places can represent the environment where people can easier incur in mite allergy. All environments could be at risk for cat allergen exposure.