Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros










Intervalo de ano de publicação
1.
Virol J ; 21(1): 15, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200555

RESUMO

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic is driven by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which has led to an enormous burden on patient morbidity and mortality. The renin-angiotensin-aldosterone system (RAAS) plays a significant role in various pulmonary diseases. Since SARS-CoV-2 utilizes the angiotensin-converting enzyme (ACE)2 receptor to exert its virulence and pathogenicity, the RAAS is of particular importance in COVID 19. METHODS: Our preliminary study investigates retrospectively the influence of selected ACE-polymorphisms (I/D location at intron 16 in the B-coding sequence (rs4646994) and A-240T (rs 4291) at the A-promoter) as well as ACE1 and ACE2 serum levels on disease severity and the inflammatory response in inpatients and outpatients with COVID-19. RESULTS: Our study included 96 outpatients and 88 inpatients (65.9% male, mean age 60 years) with COVID-19 from April to December 2020 in four locations in Germany. Of the hospitalized patients, 88.6% participants were moderately ill (n = 78, 64% male, median age 60 years), and 11.4% participants were severely ill or deceased (n = 10, 90% male, median age 71 years). We found no polymorphism-related difference in disease, in age distribution, time to hospitalization and time of hospitalization for the inpatient group. ACE1 serum levels were significantly increased in the DD compared to the II polymorphism and in the TT compared to the AA polymorphism. There was no significant difference in ACE 1 serum levels l between moderately ill and severely ill patients. However, participants requiring oxygen supplementation had significantly elevated ACE1 levels compared to participants not requiring oxygen, with no difference in ACE2 levels whereas females had significantly higher ACE2 levels. CONCLUSIONS: Although there were no differences in the distribution of ACE polymorphisms in disease severity, we found increased proinflammatory regulation of the RAAS in patients with oxygen demand and increased serum ACE2 levels in women, indicating a possible enhanced anti-inflammatory immune response. CLINICAL TRIAL REGISTRATION: PreBiSeCov: German Clinical Trials Register, DRKS-ID: DRKS00021591, Registered on 27th April 2020.


Assuntos
COVID-19 , Sistema Renina-Angiotensina , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Enzima de Conversão de Angiotensina 2/genética , Mutagênese Insercional , Oxigênio , Peptidil Dipeptidase A/genética , Sistema Renina-Angiotensina/genética , Estudos Retrospectivos , SARS-CoV-2/genética
2.
Sci Rep ; 13(1): 21846, 2023 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-38071261

RESUMO

Serological assays measuring antibodies against SARS-CoV-2 are key to describe the epidemiology, pathobiology or induction of immunity after infection or vaccination. Of those, multiplex assays targeting multiple antigens are especially helpful as closely related coronaviruses or other antigens can be analysed simultaneously from small sample volumes, hereby shedding light on patterns in the immune response that would otherwise remain undetected. We established a bead-based 17-plex assay detecting antibodies targeting antigens from all coronaviruses pathogenic for humans: SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV strains 229E, OC43, HKU1, and NL63. The assay was validated against five commercial serological immunoassays, a commercial surrogate virus neutralisation test, and a virus neutralisation assay, all targeting SARS-CoV-2. It was found to be highly versatile as shown by antibody detection from both serum and dried blot spots and as shown in three case studies. First, we followed seroconversion for all four endemic HCoV strains and SARS-CoV-2 in an outbreak study in day-care centres for children. Second, we were able to link a more severe clinical course to a stronger IgG response with this 17-plex-assay, which was IgG1 and IgG3 dominated. Finally, our assay was able to discriminate recent from previous SARS-CoV-2 infections by calculating the IgG/IgM ratio on the N antigen targeting antibodies. In conclusion, due to the comprehensive method comparison, thorough validation, and the proven versatility, our multiplex assay is a valuable tool for studies on coronavirus serology.


Assuntos
COVID-19 , Coronavirus Humano OC43 , Coronavírus da Síndrome Respiratória do Oriente Médio , Criança , Humanos , SARS-CoV-2 , Imunidade Humoral , COVID-19/diagnóstico , COVID-19/epidemiologia , Imunoglobulina G , Anticorpos Antivirais
3.
Front Microbiol ; 14: 1256210, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37937220

RESUMO

Background: COVID-19 can show a variable course, from asymptomatic infections to acute respiratory failure and death. For efficient allocation of resources, patients should be stratified according to their risk for a severe course as early as possible. Methods: 135 hospitalized patients with COVID-19 pneumonia at four German hospitals were prospectively included in this observational study. A standardized clinical laboratory profile was taken at hospital admission and a panel of serum markers with possible roles in the COVID-associated cytokine storm were also determined. 112 patients could be evaluated. The primary endpoint of ventilator requirement or death within 30 days of symptom onset was met by 13 patients. Results: Serum elevations of interleukin-6 (IL-6), procalcitonin (PCT), and C-reactive protein (CRP) at hospital admission were each highly significantly (p < 0.001) associated with ventilator requirement/death within 30 days of symptom onset. With a sensitivity of 92% and a specificity of 65-67%, IL-6 ≥ 52.8 pg/ml, PCT ≥ 0.11 ng/ml, and CRP ≥ 71.1 mg/L were predictive of a severe course of COVID-19. Positive likelihood ratios were between 2.6-2.8 and negative likelihood ratios were between 0.11-0.13 for these three markers. Conclusion: Negative likelihood ratios indicate that IL-6, PCT, and CRP at hospital admission can be used for identifying patients at low risk for severe COVID-19 progression.

5.
Surg Endosc ; 36(5): 2954-2961, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34129089

RESUMO

BACKGROUND: A recently developed haemostatic peptide gel for endoscopic application has been introduced to improve the management of gastrointestinal bleeding. The aim of this pilot study was to evaluate the feasibility, safety, efficacy and indication profiles of PuraStat in a clinical setting. METHODS: In this prospective observational multicentre pilot study, patients with acute non-variceal gastrointestinal bleeding (upper and lower) were included. Primary and secondary application of PuraStat was evaluated. Haemoglobin, prothrombin time, platelets and transfusion behaviour were documented before and after haemostasis. The efficacy of PuraStat was assessed during the procedure, at 3 days and 1 week after application. RESULTS: 111 patients with acute gastrointestinal bleeding were recruited into the study. 70 percent (78/111) of the patients had upper gastrointestinal bleeding and 30% (33/111) had lower gastrointestinal bleeding. After primary application of PuraStat, initial haemostatic success was achieved in 94% of patients (74/79, 95% CI 88-99%), and in 75% of the patients when used as a secondary haemostatic product, following failure of established techniques (24/32, 95% CI 59-91%). The therapeutic success rates (absence of rebleeding) after 3 and 7 days were 91% and 87% after primary use, and 87% and 81% in all study patients. Overall rebleeding rate at 30 day follow-up was 16% (18/111). In the 5 patients who finally required surgery (4.5%), PuraStat allowed temporary haemostasis and stabilisation. CONCLUSIONS: PuraStat expanded the therapeutic toolbox available for an effective treatment of gastrointestinal bleeding sources. It could be safely applied and administered without complications as a primary or secondary therapy. PuraStat may additionally serve as a bridge to surgery in order to achieve temporary haemostasis in case of refractory severe bleeding, possibly playing a role in preventing immediate emergency surgery.


Assuntos
Hemostase Endoscópica , Hemostáticos , Hemorragia Gastrointestinal/etiologia , Hemorragia Gastrointestinal/cirurgia , Hemostase Endoscópica/métodos , Hemostáticos/uso terapêutico , Humanos , Projetos Piloto , Estudos Prospectivos , Resultado do Tratamento
6.
Arch Toxicol ; 92(4): 1495-1505, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29380012

RESUMO

Allergic contact dermatitis is a widespread health disorder and occupational skin disease. Hence, screening for contact-sensitizing chemicals is highly relevant to toxicology, dermatology, and occupational medicine. The use of animal tests for this purpose is constrained by ethical considerations, need for high-throughput screening, and legislation (e.g., for cosmetics in the European Union). T cell activation is the final and most specific key event of the "adverse outcome pathway" for skin sensitization and therefore a promising target for the development of in vitro sensitization assays. We present a novel in vitro sensitization assay with a lymphocyte endpoint as an add-on to the loose-fit coculture-based sensitization assay (LCSA): the LCSA-ly. While the LCSA measures dendritic cell activation, the LCSA-ly offers the option for an additional lymphocyte endpoint which can be measured concurrently. We incorporated lymphocytes in our previously established coculture of primary human keratinocytes and monocyte-derived dendritic cells and tested nine substances: five sensitizers [2,4-dinitrochlorobenzene (DNCB) 1.25-15 µmol/l, p-phenylenediamine (PPD) 15.6-125 µmol/l, 2-mercaptobenzothiazole (MBT) 50-1000 µmol/l, coumarin, and resorcinol (both: 250-1500 µmol/l)] and four non-sensitizers (monochlorobenzene, caprylic acid, glycerol, and salicylic acid (all: 125-1000 µmol/l)]. DNCB and MBT increased a subset of IL-23 receptor+/IFN-γ receptor 1 (CD119)+ lymphocytes. DNCB, PPD, and MBT enhanced a subunit of the IL-4 receptor (CD124) and a memory marker (CD44) on lymphocytes. Remarkably, DNCB, PPD, and MBT raised IL-4 concentrations in coculture supernatants while IFN-γ levels decreased, which might point to Th2 activation in vitro. Coumarin, resorcinol, and non-sensitizers did not alter any of the tested surface markers or cytokines. IL-17 was not affected by any of the substances. Relative strength of sensitizers according to lymphocyte markers was DNCB > PPD > MBT, which corresponds to earlier results from the LCSA without lymphocyte endpoint, the murine local lymph node assay, and human data. This study is the first to prove the suitability of lymphocyte surface markers for sensitization testing and potency assessment.


Assuntos
Alérgenos/imunologia , Antígenos de Superfície/metabolismo , Citocinas/metabolismo , Dermatite Alérgica de Contato/imunologia , Alérgenos/toxicidade , Bioensaio , Técnicas de Cocultura , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Humanos , Receptores de Hialuronatos/metabolismo , Imunização , Subunidade alfa de Receptor de Interleucina-4/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/imunologia , Linfócitos/imunologia , Receptores de Interferon/metabolismo , Pele/efeitos dos fármacos , Pele/imunologia , Receptor de Interferon gama
7.
Food Chem ; 229: 452-457, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28372200

RESUMO

The aim of this study was to develop a high-throughput UHPLC method for the determination vitamin B1 active compounds; thiamin, thiamin monophosphate and thiamin diphosphate in bovine milk. In order to sustain the native vitamin B1 phosphorus esters, sample preparation is crucial. Various acids as well as commonly used enzymes and their enzyme mixtures were compared. Method accuracy was confirmed using certified reference material as well as comparison with the corresponding CEN method, and was found to be satisfactory. Studied milk samples showed significant amounts of thiamin monophosphate, which can make up to 53.9% of the total vitamin B1 content in commercial milk, and up to 78% in raw milk. Moreover, a tremendous variation of the total content of vitamin B1 was observed between single cows, which ranged from 0.24mg/L up to 0.54mg/L of total vitamin B1.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Leite/química , Tiamina/análise , Animais , Reprodutibilidade dos Testes
9.
Arch Toxicol ; 91(1): 339-350, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27136899

RESUMO

The in vitro sensitization assay LCSA (Loose-fit Coculture-based Sensitization Assay) has proved reliable for the detection of contact sensitizers in the past. However, the coculture of human monocyte-derived dendritic cells (DCs) with primary human keratinocytes (KCs) in serum-free medium is relatively complex compared to other sensitization assays which use continuous cell lines. To facilitate high-throughput screening of chemicals, we replaced KCs with the HaCaT cell line under various culture conditions. Coculture of HaCaT with peripheral blood mononuclear cells in serum-supplemented medium leads to generation of CD1a+/CD1c+ DCs after addition of GM-CSF, IL-4, and TGF-ß1 (as opposed to CD1a-/CD1c- DCs which arise in the "classic" LCSA coculture). These cells resemble monocyte-derived DCs generated in monoculture, but, unlike those, they show a marked upregulation CD86 after treatment with contact allergens. All of the nine sensitizers in this study were correctly identified by CD1a+/CD1c+ DCs in coculture with HaCaT. Among the substances were weak contact allergens such as propylparaben (which is false negative in the local lymph node assay in mice) and resorcinol (which was not detected by CD1a-/CD1c- DCs in the "classic" LCSA). The level of CD86 upregulation on CD1a+/CD1c+ DCs was higher for most allergens compared to CD1a-/CD1c- DCs, thus improving the assay's discriminatory power. Three out of four non-sensitizers were also correctly assessed by the coculture assay. A false-positive reaction to caprylic (octanoic) acid confirms earlier results that some fatty acids are able to induce CD86 on DC in vitro. In conclusion, change of the LCSA protocol led to reduction of time and cost while even increasing the assay's sensitivity and discriminatory power.


Assuntos
Alérgenos/toxicidade , Células Dendríticas/efeitos dos fármacos , Dermatite Alérgica de Contato/patologia , Queratinócitos/efeitos dos fármacos , Modelos Químicos , Alérgenos/análise , Antígeno B7-2/agonistas , Antígeno B7-2/metabolismo , Biomarcadores/metabolismo , Caprilatos/efeitos adversos , Caprilatos/análise , Diferenciação Celular , Linhagem Celular , Células Cultivadas , Técnicas de Cocultura , Cosméticos/química , Cosméticos/toxicidade , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/patologia , Dermatite Alérgica de Contato/etiologia , Dermatite Alérgica de Contato/imunologia , Dermatite Alérgica de Contato/metabolismo , Reações Falso-Positivas , Ácidos Graxos não Esterificados/efeitos adversos , Ácidos Graxos não Esterificados/análise , Ensaios de Triagem em Larga Escala , Humanos , Queratinócitos/imunologia , Queratinócitos/metabolismo , Queratinócitos/patologia , Leucócitos Mononucleares/citologia , Monócitos/citologia , Parabenos/toxicidade , Resorcinóis/toxicidade , Regulação para Cima
11.
Arch Toxicol ; 90(4): 927-36, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25975990

RESUMO

Unsaturated compounds are known to cause false-positive reactions in the local lymph node assay (LLNA) but not in the guinea pig maximization test. We have tested a panel of substances (succinic acid, undecylenic acid, 1-octyn-3-ol, fumaric acid, maleic acid, linoleic acid, oleic acid, alpha-linolenic acid, squalene, and arachidonic acid) in the loose-fit coculture-based sensitization assay (LCSA) to evaluate whether unspecific activation of dendritic cells is a confounder for sensitization testing in vitro. Eight out of 10 tested substances caused significant up-regulation of CD86 on dendritic cells cocultured with keratinocytes and would have been classified as sensitizers; only succinic acid was tested negative, and squalene had to be excluded from data analysis due to poor solubility in cell culture medium. Based on human data, only undecylenic acid can be considered a true sensitizer. The true sensitizing potential of 1-octyn-3-ol is uncertain. Fumaric acid and its isomer maleic acid are not known as sensitizers, but their esters are contact allergens. A group of 18- to 20-carbon chain unsaturated fatty acids (linoleic acid, oleic acid, alpha-linolenic acid, and arachidonic acid) elicited the strongest reaction in vitro. This is possibly due to the formation of pro-inflammatory lipid mediators in the cell culture causing nonspecific activation of dendritic cells. In conclusion, both the LLNA and the LCSA seem to provide false-positive results for unsaturated fatty acids. The inclusion of T cells in dendritic cell-based in vitro sensitization assays may help to eliminate false-positive results due to nonspecific dendritic cell activation. This would lead to more accurate prediction of sensitizers, which is paramount for consumer health protection and occupational safety.


Assuntos
Antígeno B7-2/metabolismo , Ácidos Graxos Insaturados/imunologia , Testes Cutâneos/métodos , Animais , Técnicas de Cocultura/métodos , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Reações Falso-Positivas , Ácidos Graxos Insaturados/toxicidade , Cobaias , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/imunologia , Ensaio Local de Linfonodo , Ácido Succínico/imunologia , Ácido Succínico/toxicidade , Regulação para Cima/efeitos dos fármacos
12.
Arch Toxicol ; 89(12): 2339-44, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25395006

RESUMO

Parabens, methylisothiazolinone (MI) and its derivative methylchloroisothiazolinone (MCI), are commonly used as preservatives in personal care products. They can cause hypersensitivity reactions of the human skin. We have tested a set of nine parabens, MI alone and in combination with MCI in the loose-fit coculture-based sensitization assay (LCSA). The coculture of primary human keratinocytes and allogenic dendritic cell-related cells (DC-rc) in this assay emulates the in vivo situation of the human skin. Sensitization potency of the test substances was assessed by flow cytometric analysis of the DC-rc maturation marker CD86. Determination of the concentration required to cause a half-maximal increase in CD86-expression (EC50sens) allowed a quantitative evaluation. The cytotoxicity of test substances as indicator for irritative potency was measured by 7-AAD (7-amino-actinomycin D) staining. Parabens exhibited weak (methyl-, ethyl-, propyl- and isopropylparaben) or strong (butyl-, isobutyl-, pentyl- and benzylparaben) effects, whereas phenylparaben was found to be a moderate sensitizer. Sensitization potencies of parabens correlated with side chain length. Due to a pronounced cytotoxicity, we could not estimate an EC50sens value for MI, whereas MI/MCI was classified as sensitizer and also showed cytotoxic effects. Parabens showed no (methyl- and ethylparaben) or weak irritative potencies (propyl-, isopropyl-, butyl-, isobutyl-, phenyl- and benzylparaben), only pentylparaben was rated to be irritative. Overall, we were able to demonstrate and compare the sensitizing potencies of parabens in this in vitro test. Furthermore, we showed an irritative potency for most of the preservatives. The data further support the usefulness of the LCSA for comparison of the sensitizing potencies of xenobiotics.


Assuntos
Parabenos/toxicidade , Conservantes Farmacêuticos/toxicidade , Pele/efeitos dos fármacos , Tiazóis/toxicidade , Técnicas de Cocultura , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/patologia , Dermatite Alérgica de Contato/etiologia , Citometria de Fluxo , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/patologia , Parabenos/administração & dosagem , Conservantes Farmacêuticos/administração & dosagem , Pele/patologia , Testes de Irritação da Pele , Tiazóis/administração & dosagem
13.
Arch Toxicol ; 86(5): 733-40, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22349058

RESUMO

Certain textile disperse dyes are known to cause allergic reactions of the human skin. Here, we examined 8 disperse dyes and 7 products of azo-cleavage of these dyes in an in vitro assay. We used the loose-fit coculture-based sensitization assay (LCSA) of primary human keratinocytes and of allogenic dendritic cell-related cells for combined testing of the sensitizing and irritative properties of these substances. The obtained data were compared to data generated in a modified version of the local lymph node assay by our working group. Disperse Blue 1 (DB1), p-nitroaniline (pNA) and p-aminoacetanilide (AAA) showed no sensitizing potential under our experimental conditions. Disperse Blue 124 (DB124), Disperse Yellow 3 (DY3), Disperse Orange 37/76 (DO37), Disperse Blue 106 (DB106), Disperse Red 1 (DR1), 2-amino-p-cresol (ApC), Disperse Orange 3 (DO3) and 2,6-dichloro-4-nitroaniline (DCh) were categorized as extreme sensitizers. Para-phenylenediamine (pPD) was categorized as strong sensitizer, and 2-amino-5-nitrothiazole (ANT) and 2-(N-ethylanilino)-ethanol (EAE) as weak sensitizers. All dyes, except for DB1, and ApC turned out to be strong irritants. DB1, ANT and DCh showed only weak irritative potential. PPD, pNA, EAE and AAA did not show any irritative effect at the concentration range tested. These results correlate with data derived from the modified version of LLNA and human data. Therefore, the LCSA represents a suitable test system to simultaneously analyse two crucial properties of substances relevant for allergy induction.


Assuntos
Corantes/toxicidade , Testes de Toxicidade/métodos , Animais , Antraquinonas/toxicidade , Compostos Azo/toxicidade , Células Cultivadas , Técnicas de Cocultura , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Dermatite Alérgica de Contato/etiologia , Humanos , Queratinócitos/efeitos dos fármacos , Ensaio Local de Linfonodo , Camundongos
15.
Toxicol Appl Pharmacol ; 245(2): 211-8, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20219181

RESUMO

We have developed a coculture system which in parallel indicates the sensitizing and irritative potential of xenobiotics. The assay is named loose-fit coculture-based sensitization assay (LCSA) and may be performed within 5 days. The system is composed of human monocytes that differentiate to a kind of dendritic cells by 2-day culturing in the presence of allogenic keratinocytes. The culture medium is enriched by a cocktail of recombinant cytokines. On day 3, concentration series of probes are added. On day 5, cells are harvested and analyzed for expression range of CD86 as a marker of sensitizing potential and for uptake of the viability stain 7-AAD as a marker of irritative potential. Estimation of the concentration required to cause a half-maximal increase in CD86 expression allowed quantification of sensitizing potential, and estimation of the concentration required to reduce viability to 50% allowed quantification of irritative potential. Examination of substances with known potential resulted in categorization of test scores. To evaluate our data, we have compared results with those of the validated animal-based sensitization test, the murine local lymph node assay (LLNA, OECD TG 429). To a large extent, results from LCSA and from LLNA achieved analogous grouping of allergens into categories like weak-moderate-strong. However, the new assay showed an improved capacity to distinguish sensitizers from non-sensitizers and irritants. In conclusion, the LCSA contains potential to fulfil the requirements of the EU's programme for the safety of chemicals "Registration, Evaluation, Authorization and Restriction of chemical substances" (REACH, 2006) to replace animal models.


Assuntos
Alérgenos/toxicidade , Irritantes/toxicidade , Xenobióticos/toxicidade , Alérgenos/imunologia , Animais , Antígeno B7-2/metabolismo , Bioensaio , Diferenciação Celular , Técnicas de Cocultura , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Dermatite Alérgica de Contato/imunologia , Humanos , Irritantes/imunologia , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Camundongos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Hipersensibilidade Respiratória/imunologia , Xenobióticos/imunologia
16.
Mem Inst Oswaldo Cruz ; 104(2): 221-33, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19430647

RESUMO

Small intestinal immunopathology following oral infection with tissue cysts of Toxoplasma gondii has been described in C57BL/6 mice. Seven days after infection, mice develop severe small intestinal necrosis and succumb to infection. The immunopathology is mediated by local overproduction of Th1-type cytokines, a so-called 'cytokine storm'. The immunopathogenesis of this pathology resembles that of inflammatory bowel disease in humans, i.e., Crohn's disease. In this review, we show that the development of intestinal pathology following oral ingestion of T. gondii is not limited to C57BL/6 mice, but frequently occurs in nature. Using a Pubmed search, we identified 70 publications that report the development of gastrointestinal inflammation following infection with T. gondii in 63 animal species. Of these publications, 53 reports are on accidental ingestion of T. gondii in 49 different animal species and 17 reports are on experimental infections in 19 different animal species. Thus, oral infection with T. gondii appears to cause immunopathology in a large number of animal species in addition to mice. This manuscript reviews the common features of small intestinal immunopathology in the animal kingdom and speculates on consequences of this immunopathology for humankind.


Assuntos
Citocinas/imunologia , Doenças Inflamatórias Intestinais/parasitologia , Intestino Delgado/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/patologia , Animais , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Intestino Delgado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/transmissão
17.
Eur J Immunol ; 39(5): 1221-30, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19350551

RESUMO

The cytokines IL-6, IL-1beta, TGF-beta, and IL-23 are considered to promote Th17 commitment. Langerhans cells (LC) represent DC in the outer skin layers of the epidermis, an environment extensively exposed to pathogenic attack. The question whether organ-resident DC like LC can evoke Th17 immune response is still open. Our results show that upon stimulation by bacterial agonists, epidermal LC and LC-like cells TLR2-dependently acquire the capacity to polarize Th17 cells. In Th17 cells, expression of retinoid orphan receptor gammabeta was detected. To clarify if IL-17(+)cells could arise per se by stimulated LC we did not repress Th1/Th2 driving pathways by antibodies inhibiting differentiation. In CD1c(+)/langerin(+) monocyte-derived LC-like cells (MoLC), macrophage-activating lipopeptide 2, and peptidoglycan (PGN) induced the release of the cytokines IL-6, IL-1beta, and IL-23. TGF-beta, a cytokine required for LC differentiation and survival, was found to be secreted constitutively. Anti-TLR2 inhibited secretion of IL-6, IL-1beta, and IL-23 by MoLC, while TGF-beta was unaffected. The amount of IL-17 and the ratio of IL-17 to IFN-gamma expression was higher in MoLC- than in monocyte-derived DC-cocultured Th cells. Anti-IL-1beta, -TGF-beta and -IL-23 decreased the induction of Th17 cells. Interestingly, blockage of TLR2 on PGN-stimulated MoLC prevented polarization of Th cells into Th17 cells. Thus, our findings indicate a role of TLR2 in eliciting Th17 immune responses in inflamed skin.


Assuntos
Interleucina-17/imunologia , Interleucina-1beta/imunologia , Células de Langerhans/imunologia , Receptor 2 Toll-Like/imunologia , Fator de Crescimento Transformador beta/imunologia , Linfócitos T CD4-Positivos/imunologia , Técnicas de Cocultura , DNA Bacteriano/imunologia , Feminino , Citometria de Fluxo , Humanos , Subunidade p19 da Interleucina-23/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares , Poli I-C/imunologia , Poli U/imunologia , RNA/química , RNA/genética , Receptores do Ácido Retinoico/genética , Receptores do Ácido Retinoico/imunologia , Receptores dos Hormônios Tireóideos/genética , Receptores dos Hormônios Tireóideos/imunologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Pele/citologia , Receptor 2 Toll-Like/antagonistas & inibidores
18.
Mem. Inst. Oswaldo Cruz ; 104(2): 221-233, Mar. 2009. tab
Artigo em Inglês | LILACS | ID: lil-533511

RESUMO

Small intestinal immunopathology following oral infection with tissue cysts of Toxoplasma gondii has been described in C57BL/6 mice. Seven days after infection, mice develop severe small intestinal necrosis and succumb to infection. The immunopathology is mediated by local overproduction of Th1-type cytokines, a so-called "cytokine storm". The immunopathogenesis of this pathology resembles that of inflammatory bowel disease in humans, i.e., Crohn's disease. In this review, we show that the development of intestinal pathology following oral ingestion of T. gondii is not limited to C57BL/6 mice, but frequently occurs in nature. Using a Pubmed search, we identified 70 publications that report the development of gastrointestinal inflammation following infection with T. gondii in 63 animal species. Of these publications, 53 reports are on accidental ingestion of T. gondii in 49 different animal species and 17 reports are on experimental infections in 19 different animal species. Thus, oral infection with T. gondii appears to cause immunopathology in a large number of animal species in addition to mice. This manuscript reviews the common features of small intestinal immunopathology in the animal kingdom and speculates on consequences of this immunopathology for humankind.


Assuntos
Animais , Camundongos , Citocinas/imunologia , Doenças Inflamatórias Intestinais/parasitologia , Intestino Delgado/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/patologia , Modelos Animais de Doenças , Doenças Inflamatórias Intestinais/imunologia , Doenças Inflamatórias Intestinais/patologia , Intestino Delgado/patologia , Toxoplasmose Animal/imunologia , Toxoplasmose Animal/transmissão
19.
Toxicology ; 249(2-3): 146-52, 2008 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-18547706

RESUMO

Establishing of alternatives to animal tests is ethically desirable and gains in importance in context of new European Union regulations such as REACH. We have refined our new in vitro assay for prediction of the sensitizing potency of xenobiotics. Monocytes cocultured with primary human keratinocytes develop to a novel class of in vitro generated dendritic cells after treatment with transforming growth factor beta and Interleukin-4 in serum-free medium. These dendritic cell-related cells (DCrc) are the key players in the loose-fit coculture-based sensitization assay (LCSA). Assay duration and cytokine consumption could be cut down without impairing the assay's functionality. DCrc showed a dose-dependent upregulation of CD86 after treatment with the contact allergens 2,4,6-trinitrobenzenesulfonic acid, the prohapten isoeugenol, and alpha-hexyl cinnamic aldehyde. The metal allergens nickel and cobalt could be detected by measuring Interleukin-6 and macrophage inflammatory protein 1-beta (MIP-1beta, CCL-4) in coculture supernatants. The irritant zinc elicited no reaction. Lipopolysaccharide produced upregulation of CD86, IL-6 and MIP-1beta. Determination of tolerable concentrations of an allergen in consumer products requires a widely accepted sharp quantitative assay. Animal-based assays do not meet this requirement. The LCSA provides dose-response information, thereby allowing prediction of the relative ability of a substance to induce sensitization.


Assuntos
Alérgenos/imunologia , Células Dendríticas/imunologia , Dermatite de Contato/imunologia , Alérgenos/toxicidade , Antígeno B7-2/imunologia , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura , Ensaio de Imunoadsorção Enzimática , Eugenol/análogos & derivados , Eugenol/imunologia , Eugenol/toxicidade , Citometria de Fluxo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Indicadores e Reagentes , Interleucina-4/farmacologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/toxicidade , Metais/imunologia , Metais/toxicidade , Monócitos/efeitos dos fármacos , Fator de Crescimento Transformador beta/farmacologia
20.
ALTEX ; 25(2): 115-20, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18551235

RESUMO

We are developing a new, animal-free assay for determination of the sensitizing potential of a substance. The design of this assay is based on current immunological knowledge of the pathogenesis of allergic contact dermatitis. It integrates human dendritic cells and keratinocytes, which are both known to be critically involved in vivo. The read-out system uses molecular responses typically occurring after an encounter of the skin with contact allergens. The assay provides concentration-response information, by which the relative ability of a chemical to induce sensitization can be predicted. Additionally, the assay defines the border-concentration of general toxicity of a substance. Weak allergens and even prohaptens are detectable. We have called the assay LCSA, loose-fit coculture-based sensitization assay.


Assuntos
Alérgenos/farmacologia , Células Dendríticas/imunologia , Dermatite de Contato/imunologia , Queratinócitos/imunologia , Alérgenos/toxicidade , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Tinturas para Cabelo/farmacologia , Tinturas para Cabelo/toxicidade , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...