Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
2.
Front Immunol ; 12: 751683, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34804037

RESUMO

Innate immune memory, the ability of innate cells to react in a more protective way to secondary challenges, is induced by exposure to infectious and other exogeous and endogenous agents. Engineered nanoparticles are particulate exogenous agents that, as such, could trigger an inflammatory reaction in monocytes and macrophages and could therefore be also able to induce innate memory. Here, we have evaluated the capacity of engineered gold nanoparticles (AuNPs) to induce a memory response or to modulate the memory responses induced by microbial agents. Microbial agents used were in soluble vs. particulate form (MDP and the gram-positive bacteria Staphylococcus aureus; ß-glucan and the ß-glucan-producing fungi C. albicans), and as whole microrganisms that were either killed (S. aureus, C. albicans) or viable (the gram-negative bacteria Helicobacter pylori). The memory response was assessed in vitro, by exposing human primary monocytes from 2-7 individual donors to microbial agents with or without AuNPs (primary response), then resting them for 6 days to allow return to baseline, and eventually challenging them with LPS (secondary memory response). Primary and memory responses were tested as production of the innate/inflammatory cytokine TNFα and other inflammatory and anti-inflammatory factors. While inactive on the response induced by soluble microbial stimuli (muramyl dipeptide -MDP-, ß-glucan), AuNPs partially reduced the primary response induced by whole microorganisms. AuNPs were also unable to directly induce a memory response but could modulate stimulus-induced memory in a circumscribed fashion, limited to some agents and some cytokines. Thus, the MDP-induced tolerance in terms of TNFα production was further exacerbated by co-priming with AuNPs, resulting in a less inflammatory memory response. Conversely, the H. pylori-induced tolerance was downregulated by AuNPs only relative to the anti-inflammatory cytokine IL-10, which would lead to an overall more inflammatory memory response. These effects of AuNPs may depend on a differential interaction/association between the reactive particle surfaces and the microbial components and agents, which may lead to a change in the exposure profiles. As a general observation, however, the donor-to-donor variability in memory response profiles and reactivity to AuNPs was substantial, suggesting that innate memory depends on the individual history of exposures.

3.
Nanoscale ; 13(16): 7648-7666, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33928963

RESUMO

Dendritic cells (DCs) shape immune responses by influencing T-cell activation. Thus, they are considered both an interesting model for studying nano-immune interactions and a promising target for nano-based biomedical applications. However, the accentuated ability of nanoparticles (NPs) to interact with biomolecules may have an impact on DC function that poses an unexpected risk of unbalanced immune reactions. Here, we investigated the potential effects of gold nanoparticles (AuNPs) on DC function and the consequences for effector and memory T-cell responses in the presence of the microbial inflammatory stimulus lipopolysaccharide (LPS). Overall, we found that, in the absence of LPS, none of the tested NPs induced a DC response. However, whereas 4-, 8-, and 11 nm AuNPs did not modulate LPS-dependent immune responses, 26 nm AuNPs shifted the phenotype of LPS-activated DCs toward a tolerogenic state, characterized by downregulation of CD86, IL-12 and IL-27, upregulation of ILT3, and induction of class E compartments. Moreover, this DC phenotype was less proficient in promoting Th1 activation and central memory T-cell proliferation. Taken together, these findings support the perception that AuNPs are safe under homeostatic conditions; however, particular care should be taken in patients experiencing a current infection or disorders of the immune system.


Assuntos
Ouro , Nanopartículas Metálicas , Células Dendríticas , Humanos , Lipopolissacarídeos , Nanopartículas Metálicas/toxicidade , Fenótipo
4.
Int J Mol Sci ; 22(3)2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33525345

RESUMO

Chronic inflammation contributes to the development and progression of various tumors. Especially where the inflammation is mediated by cells of the innate immune system, the NLRP3 inflammasome plays an important role, as it senses and responds to a variety of exogenous and endogenous pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs). The NLRP3 inflammasome is responsible for the maturation and secretion of the proinflammatory cytokines interleukin-1ß (IL-1ß) and IL-18 and for the induction of a type of inflammatory cell death known as pyroptosis. Overactivation of the NLRP3 inflammasome can be a driver of various diseases. Since leukemia is known to be an inflammation-driven cancer and IL-1ß is produced in elevated levels by leukemic cells, research on NLRP3 in the context of leukemia has increased in recent years. In this review, we summarize the current knowledge on leukemia-promoting inflammation and, in particular, the role of the NLRP3 inflammasome in different types of leukemia. Furthermore, we examine a connection between NLRP3, autophagy and leukemia.


Assuntos
Carcinogênese/imunologia , Inflamassomos/imunologia , Inflamação/imunologia , Leucemia/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/imunologia , Alarminas/genética , Alarminas/imunologia , Animais , Autofagia/genética , Autofagia/imunologia , Carcinogênese/genética , Carcinogênese/patologia , Progressão da Doença , Regulação Leucêmica da Expressão Gênica , Humanos , Imunidade Inata , Inflamassomos/genética , Inflamação/complicações , Inflamação/genética , Inflamação/patologia , Interleucina-18/genética , Interleucina-18/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Leucemia/etiologia , Leucemia/genética , Leucemia/patologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Padrões Moleculares Associados a Patógenos/imunologia , Padrões Moleculares Associados a Patógenos/metabolismo , Piroptose/genética , Piroptose/imunologia , Transdução de Sinais
5.
Eur J Immunol ; 51(1): 191-196, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32648940

RESUMO

Interleukin-31 (IL-31) is a Th2 cell-derived cytokine that has been closely linked to pruritic skin inflammation. More recently, enhanced IL-31 serum levels have also been observed in patients with allergic rhinitis and allergic asthma. Therefore, the main aim of this study was to unravel the contribution of IL-31 to allergen-induced lung inflammation. We analyzed lung inflammation in response to the timothy grass (Phleum pratense) pollen allergen Phl p 5 in C57BL/6 wild-type (wt) mice, IL-31 transgenic (IL-31tg) mice, and IL-31 receptor alpha-deficient animals (IL-31RA-/- ). IL-31 and IL-31RA levels were monitored by qRT-PCR. Cellular infiltrate in bronchoalveolar lavage fluid (BALF) and lung tissue inflammation, mucus production as well as epithelial thickness were measured by flow cytometry and histomorphology. While allergen challenge induced IL-31RA expression in lung tissue of wt and IL-31tg mice, high IL-31 expression was exclusively observed in lung tissue of IL-31tg mice. Upon Phl p 5 challenge, IL-31tg mice showed reduced numbers of leukocytes and eosinophils in BALF and lung tissue as well as diminished mucin expression and less pronounced epithelial thickening compared to IL-31RA-/- or wt animals. These findings suggest that the IL-31/IL-31RA axis may regulate local, allergen-induced inflammation in the lungs.


Assuntos
Alérgenos/efeitos adversos , Alérgenos/imunologia , Interleucinas/imunologia , Proteínas de Plantas/efeitos adversos , Proteínas de Plantas/imunologia , Pneumonia/imunologia , Animais , Asma/etiologia , Asma/imunologia , Asma/prevenção & controle , Líquido da Lavagem Broncoalveolar/imunologia , Modelos Animais de Doenças , Eosinófilos/imunologia , Feminino , Interleucinas/genética , Leucócitos/imunologia , Pulmão/imunologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Phleum/efeitos adversos , Phleum/imunologia , Pneumonia/etiologia , Pneumonia/prevenção & controle , Pólen/efeitos adversos , Pólen/imunologia , Receptores de Interleucina/deficiência , Receptores de Interleucina/genética , Receptores de Interleucina/imunologia
6.
Allergy ; 76(1): 210-222, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32621318

RESUMO

BACKGROUND: Allergen-specific immunotherapy via the skin targets a tissue rich in antigen-presenting cells, but can be associated with local and systemic side effects. Allergen-polysaccharide neoglycogonjugates increase immunization efficacy by targeting and activating dendritic cells via C-type lectin receptors and reduce side effects. OBJECTIVE: We investigated the immunogenicity, allergenicity, and therapeutic efficacy of laminarin-ovalbumin neoglycoconjugates (LamOVA). METHODS: The biological activity of LamOVA was characterized in vitro using bone marrow-derived dendritic cells. Immunogenicity and therapeutic efficacy were analyzed in BALB/c mice. Epicutaneous immunotherapy (EPIT) was performed using fractional infrared laser ablation to generate micropores in the skin, and the effects of LamOVA on blocking IgG, IgE, cellular composition of BAL, lung, and spleen, lung function, and T-cell polarization were assessed. RESULTS: Conjugation of laminarin to ovalbumin reduced its IgE binding capacity fivefold and increased its immunogenicity threefold in terms of IgG generation. EPIT with LamOVA induced significantly higher IgG levels than OVA, matching the levels induced by s.c. injection of OVA/alum (SCIT). EPIT was equally effective as SCIT in terms of blocking IgG induction and suppression of lung inflammation and airway hyperresponsiveness, but SCIT was associated with higher levels of therapy-induced IgE and TH2 cytokines. EPIT with LamOVA induced significantly lower local skin reactions during therapy compared to unconjugated OVA. CONCLUSION: Conjugation of ovalbumin to laminarin increased its immunogenicity while at the same time reducing local side effects. LamOVA EPIT via laser-generated micropores is safe and equally effective compared to SCIT with alum, without the need for adjuvant.


Assuntos
Asma , Pneumonia , beta-Glucanas , Alérgenos , Animais , Asma/terapia , Lasers , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina
7.
Int J Mol Sci ; 23(1)2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-35008838

RESUMO

Streptococcal pyrogenic exotoxin B (SpeB) is a cysteine protease expressed during group A streptococcal infection that represents a major virulence factor. Although subject to several studies, its role during infection is still under debate, and its proteolytic properties remain insufficiently characterized. Here, we revisited this protease through a set of complementary approaches relying on state of-the-art HPLC-MS methods. After conceiving an efficient protocol to recombinantly express SpeB, the zymogen of the protease and its activation were characterized. Employing proteome-derived peptide libraries, a strong preference for hydrophobic and aromatic residues at P2 alongside negatively charged amino acids at P3' to P6' was revealed. To identify relevant in vivo substrates, native proteins were obtained from monocytic secretome and plasma to assess their cleavage under physiological conditions. Besides corroborating our findings concerning specificity, more than 200 cleaved proteins were identified, including proteins of the extracellular matrix, proteins of the immune system, and proteins involved in inflammation. Finally, the cleavage of IgG subclasses was studied in detail. This study precisely depicts the proteolytic properties of SpeB and provides a library of potential host substrates, including their exact cleavage positions, as a valuable source for further research to unravel the role of SpeB during streptococcal infection.

8.
Front Immunol ; 11: 1824, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33013833

RESUMO

Introduction: Understanding, which factors determine the immunogenicity and immune polarizing properties of proteins, is an important prerequisite for designing better vaccines and immunotherapeutics. While extrinsic immune modulatory factors such as pathogen associated molecular patterns are well-understood, far less is known about the contribution of protein inherent features. Protein fold-stability represents such an intrinsic feature contributing to immunogenicity and immune polarization by influencing the amount of peptide-MHC II complexes (pMHCII). Here, we investigated how modulation of the fold-stability of the grass pollen allergen Phl p 6 affects its ability to stimulate immune responses and T cell polarization. Methods: MAESTRO software was used for in silico prediction of stabilizing or destabilizing point mutations. Mutated proteins were expressed in E. coli, and their thermal stability and resistance to endolysosomal proteases was determined. Resulting peptides were analyzed by mass spectrometry. The structure of the most stable mutant protein was assessed by X-ray crystallography. We evaluated the capacity of the mutants to stimulate T cell proliferation in vitro, as well as antibody responses and T cell polarization in vivo in an adjuvant-free BALB/c mouse model. Results: In comparison to wild-type protein, stabilized or destabilized mutants displayed changes in thermal stability ranging from -5 to +14°. While highly stabilized mutants were degraded very slowly, destabilization led to faster proteolytic processing in vitro. This was confirmed in BMDCs, which processed and presented the immunodominant epitope from a destabilized mutant more efficiently compared to a highly stable mutant. In vivo, stabilization resulted in a shift in immune polarization from TH2 to TH1/TH17 as indicated by higher levels of IgG2a and increased secretion of TNF-α, IFN-γ, IL-17, and IL-21. Conclusion: MAESTRO software was very efficient in detecting single point mutations that increase or reduce fold-stability. Thermal stability correlated well with the speed of proteolytic degradation and presentation of peptides on the surface of dendritic cells in vitro. This change in processing kinetics significantly influenced the polarization of T cell responses in vivo. Modulating the fold-stability of proteins thus has the potential to optimize and polarize immune responses, which opens the door to more efficient design of molecular vaccines.


Assuntos
Alérgenos/química , Alérgenos/genética , Alérgenos/imunologia , Apresentação do Antígeno/imunologia , Simulação por Computador , Ativação Linfocitária/imunologia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Animais , Células Dendríticas/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Mutação Puntual , Dobramento de Proteína , Estabilidade Proteica , Linfócitos T/imunologia
9.
Cell Commun Signal ; 18(1): 160, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33023610

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) is a gram-negative bacterium that chronically infects approximately 50% of the world's human population. While in most cases the infection remains asymptomatic, 10% of infected individuals develop gastric pathologies and 1-3% progress to gastric cancer. Although H. pylori induces severe inflammatory responses, the host's immune system fails to clear the pathogen and H. pylori can persist in the human stomach for decades. As suppressor of cytokine signaling (SOCS) proteins are important feedback regulators limiting inflammatory responses, we hypothesized that H. pylori could modulate the host's immune responses by inducing SOCS expression. METHODS: The phenotype of human monocyte-derived DCs (moDCs) infected with H. pylori was analyzed by flow cytometry and multiplex technology. SOCS expression levels were monitored by qPCR and signaling studies were conducted by means of Western blot. For functional studies, RNA interference-based silencing of SOCS1-3 and co-cultures with CD4+ T cells were performed. RESULTS: We show that H. pylori positive gastritis patients express significantly higher SOCS3, but not SOCS1 and SOCS2, levels compared to H. pylori negative patients. Moreover, infection of human moDCs with H. pylori rapidly induces SOCS3 expression, which requires the type IV secretion system (T4SS), release of TNFα, and signaling via the MAP kinase p38, but appears to be independent of TLR2, TLR4, MEK1/2 and STAT proteins. Silencing of SOCS3 expression in moDCs prior to H. pylori infection resulted in increased release of both pro- and anti-inflammatory cytokines, upregulation of PD-L1, and decreased T-cell proliferation. CONCLUSIONS: This study shows that H. pylori induces SOCS3 via an autocrine loop involving the T4SS and TNFα and p38 signaling. Moreover, we demonstrate that high levels of SOCS3 in DCs dampen PD-L1 expression on DCs, which in turn drives T-cell proliferation. Video Abstract.


Assuntos
Sistemas de Secreção Bacterianos , Células Dendríticas/metabolismo , Células Dendríticas/microbiologia , Helicobacter pylori/fisiologia , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Antígenos de Bactérias/metabolismo , Antígeno B7-H1/metabolismo , Proteínas de Bactérias/metabolismo , Proliferação de Células , Quimiocinas/metabolismo , Retroalimentação Fisiológica , Infecções por Helicobacter/metabolismo , Humanos , Janus Quinases/metabolismo , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Monócitos/metabolismo , Mutação/genética , Fosforilação , Transdução de Sinais , Receptores Toll-Like/metabolismo
10.
Pathog Dis ; 78(7)2020 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-32866262

RESUMO

Persistent infections with the bacterial group-I carcinogen Helicobacter pylori (H. pylori) have been associated with a broad range of gastric disorders, including gastritis, ulceration, gastric cancer or mucosa-associated lymphoid tissue (MALT) lymphoma. Pathogenesis of H. pylori requires a balance between immune tolerance and defense. Although H. pylori induces inflammatory responses, the immune system cannot eliminate the pathogen. The detailed molecular mechanisms of how H. pylori interferes with cells of the immune system, in particular infiltrated B cells, are not well investigated. Previously, it was shown that the bacterial effector and oncoprotein cytotoxin-associated gene A (CagA) is delivered into B cells followed by its tyrosine-phosphorylation. To investigate the functional consequences in B cells colonized by CagA-positive H. pylori, we analyzed the global transcriptome of H. pylori-infected Mec-1 cells by RNA sequencing. We found 889 differentially expressed genes (DEGs) and validated JUN, FOSL2, HSPA1B, SRC, CXCR3, TLR-4, TNF-α, CXCL8, CCL2, CCL4, MHC class I and MHC class II molecules by qPCR, western blot, flow cytometry and ELISA assays. The H. pylori-specific mRNA expression signature reveals a downregulation of inflammation- and migration-associated genes, whereas central signal transduction regulators of cell survival and death are upregulated.


Assuntos
Linfócitos B/imunologia , Linfócitos B/metabolismo , Infecções por Helicobacter/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/fisiologia , Interações Hospedeiro-Patógeno/genética , Transcriptoma , Biologia Computacional/métodos , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Infecções por Helicobacter/complicações , Infecções por Helicobacter/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Linfoma de Zona Marginal Tipo Células B/etiologia , Reprodutibilidade dos Testes , Neoplasias Gástricas/etiologia
11.
Sci Rep ; 10(1): 11164, 2020 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-32636404

RESUMO

Human skin contains a population of memory T cells that supports tissue homeostasis and provides protective immunity. The study of human memory T cells is often restricted to in vitro studies and to human PBMC serving as primary cell source. Because the tissue environment impacts the phenotype and function of memory T cells, it is crucial to study these cells within their tissue. Here we utilized immunodeficient NOD-scid IL2rγnull (NSG) mice that carried in vivo-generated engineered human skin (ES). ES was generated from human keratinocytes and fibroblasts and was initially devoid of skin-resident immune cells. Upon adoptive transfer of human PBMC, this reductionist system allowed us to study human T cell recruitment from a circulating pool of T cells into non-inflamed human skin in vivo. Circulating human memory T cells preferentially infiltrated ES and showed diverse functional profiles of T cells found in fresh human skin. The chemokine and cytokine microenvironment of ES closely resembled that of non-inflamed human skin. Upon entering the ES T cells assumed a resident memory T cell-like phenotype in the absence of infection, and a proportion of these cutaneous T cells can be locally activated upon injection of monocyte derived dendritic cells (moDCs) that presented Candida albicans. Interestingly, we found that CD69+ memory T cells produced higher levels of effector cytokines in response to Candida albicans, compared to CD69- T cells. Overall, this model has broad utility in many areas of human skin immunology research, including the study of immune-mediated skin diseases.


Assuntos
Memória Imunológica , Pele/imunologia , Linfócitos T/imunologia , Adulto , Animais , Linfócitos T CD4-Positivos/imunologia , Candida albicans/imunologia , Feminino , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Endogâmicos NOD , Pessoa de Meia-Idade , Pele/citologia , Transplante de Pele , Engenharia Tecidual
12.
Int J Mol Sci ; 21(11)2020 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-32486097

RESUMO

Helicobacter pylori (H. pylori) is a stomach pathogen that persistently colonizes the gastric mucosa, often leading to chronic inflammation and gastric pathologies. Although infection with H. pylori is the primary risk factor for gastric cancer, the underlying mechanisms of pathogen persistence and consequential chronic inflammation are still not well understood. Conventional dendritic cells (cDCs), which are among the first immune cells to encounter H. pylori in the gastric lining, and the cytokines and chemokines they secrete, contribute to both acute and chronic inflammation. Therefore, this study aimed to unravel the contributions of specific signaling pathways within human CD1c+ cDCs (cDC2s) to the composition of secreted cytokines and chemokines in H. pylori infection. Here, we show that the type IV secretion system (T4SS) plays only a minor role in H. pylori-induced activation of cDC2s. In contrast, Toll-like receptor 4 (TLR4) signaling drives the secretion of inflammatory mediators, including IL-12 and IL-18, while signaling via TLR10 attenuates the release of IL-1ß and other inflammatory cytokines upon H. pylori infection. The TLR2 pathway significantly blocks the release of CXCL1 and CXCL8, while it promotes the secretion of TNFα and GM-CSF. Taken together, these results highlight how specific TLR-signaling pathways in human cDC2s shape the H. pylori-induced cytokine and chemokine milieu, which plays a pivotal role in the onset of an effective immune response.


Assuntos
Quimiocinas/metabolismo , Citocinas/metabolismo , Células Dendríticas/metabolismo , Células Dendríticas/microbiologia , Receptor 10 Toll-Like/metabolismo , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo , Antígenos CD1/metabolismo , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Humanos , Inflamação , Mediadores da Inflamação/metabolismo , Leucócitos Mononucleares/citologia , Transdução de Sinais , Neoplasias Gástricas/microbiologia
13.
Small ; 16(21): e2000598, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32363795

RESUMO

The interaction of a living organism with external foreign agents is a central issue for its survival and adaptation to the environment. Nanosafety should be considered within this perspective, and it should be examined that how different organisms interact with engineered nanomaterials (NM) by either mounting a defensive response or by physiologically adapting to them. Herein, the interaction of NM with one of the major biological systems deputed to recognition of and response to foreign challenges, i.e., the immune system, is specifically addressed. The main focus is innate immunity, the only type of immunity in plants, invertebrates, and lower vertebrates, and that coexists with adaptive immunity in higher vertebrates. Because of their presence in the majority of eukaryotic living organisms, innate immune responses can be viewed in a comparative context. In the majority of cases, the interaction of NM with living organisms results in innate immune reactions that eliminate the possible danger with mechanisms that do not lead to damage. While in some cases such interaction may lead to pathological consequences, in some other cases beneficial effects can be identified.


Assuntos
Imunidade Inata , Nanoestruturas , Medição de Risco , Imunidade Adaptativa , Animais , Imunidade Inata/efeitos dos fármacos , Nanoestruturas/toxicidade , Medição de Risco/métodos
14.
Allergy ; 75(2): 412-422, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31444907

RESUMO

BACKGROUND: Food allergy is associated with a high personal health and economic burden. For immunomodulation toward tolerance, food compounds could be chemically modified, for example, by posttranslational protein nitration, which also occurs via diet-derived nitrating agents in the gastrointestinal tract. OBJECTIVE: We sought to analyze the effect of pretreatment with nitrated food proteins on the immune response in a mouse food allergy model and on human monocyte-derived dendritic cells (moDCs) and PBMCs. METHODS: The model allergen ovalbumin (OVA) was nitrated in different nitration degrees, and the secondary structures of proteins were determined by circular dichroism (CD). Allergy-preventive treatment with OVA, nitrated OVA (nOVA), and maximally nitrated OVA (nOVAmax) were performed before mice were immunized with or without gastric acid-suppression medication. Antibody levels, regulatory T-cell (Treg) numbers, and cytokine levels were evaluated. Human moDCs or PBMCs were incubated with proteins and evaluated for expression of surface markers, cytokine production, and proliferation of Th2 as well as Tregs. RESULTS: In contrast to OVA and nOVA, the conformation of nOVAmax was substantially changed. nOVAmax pretreated mice had decreased IgE as well as IgG1 and IgG2a levels and Treg numbers were significantly elevated, while cytokine levels remained at baseline level. nOVAmax induced a regulatory DC phenotype evidenced by a decrease of the activation marker CD86 and an increase in IL-10 production and was associated with a higher proliferation of memory Tregs. CONCLUSION: Oral pretreatment with highly nitrated proteins induces a tolerogenic immune response in the food allergy model and in human immune cells.


Assuntos
Alérgenos/química , Alérgenos/imunologia , Hipersensibilidade Alimentar/prevenção & controle , Imunização/métodos , Nitrocompostos/imunologia , Ovalbumina/química , Ovalbumina/imunologia , Linfócitos T Reguladores/imunologia , Administração Oral , Alérgenos/administração & dosagem , Animais , Doadores de Sangue , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/imunologia , Modelos Animais de Doenças , Feminino , Hipersensibilidade Alimentar/imunologia , Humanos , Tolerância Imunológica/imunologia , Imunoglobulina E/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Nitrocompostos/administração & dosagem , Ovalbumina/administração & dosagem , Transdução de Sinais/imunologia
15.
Allergy ; 75(5): 1217-1228, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31880319

RESUMO

BACKGROUND: Skin-based immunotherapy of type 1 allergies has recently been re-investigated as an alternative for subcutaneous injections. In the current study, we employed a mouse model of house dust mite (HDM)-induced lung inflammation to explore the potential of laser-facilitated epicutaneous allergen-specific treatment. METHODS: Mice were sensitized against native Dermatophagoides pteronyssinus extract and repeatedly treated by application of depigmented D pteronyssinus extract via laser-generated skin micropores or by subcutaneous injection with or without alum. Following aerosol challenges, lung function was determined by whole-body plethysmography and bronchoalveolar lavage fluid was analyzed for cellular composition and cytokine levels. HDM-specific IgG subclass antibodies were determined by ELISA. Serum as well as cell-bound IgE was measured by ELISA, rat basophil leukemia cell assay, and ex vivo using a basophil activation test, respectively. Cultured lymphocytes were analyzed for cytokine secretion profiles and cellular polarization by flow cytometry. RESULTS: Immunization of mice by subcutaneous injection or epicutaneous laser microporation induced comparable IgG antibody levels, but the latter preferentially induced regulatory T cells and in general downregulated T cell cytokine production. This effect was found to be a result of the laser treatment itself, independent from extract application. Epicutaneous treatment of sensitized animals led to induction of blocking IgG, and improvement of lung function, superior compared to the effects of subcutaneous therapy. During the whole therapy schedule, no local or systemic side effects occurred. CONCLUSION: Allergen-specific immunotherapy with depigmented HDM extract via laser-generated skin micropores offers a safe and effective treatment option for HDM-induced allergy and lung inflammation.


Assuntos
Alérgenos , Hipersensibilidade , Animais , Antígenos de Dermatophagoides , Dessensibilização Imunológica , Hipersensibilidade/terapia , Lasers , Camundongos , Pyroglyphidae
16.
Int J Mol Sci ; 20(23)2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31775389

RESUMO

Dendritic cells (DCs) regulate immunity and inflammation and respond to various stimuli, including cytokines. IL-1ß is a key cytokine in the course of both acute and chronic inflammatory responses, making it indispensable for protection of the host, but also linking it to several diseases. Thus, IL-1ß signaling must be tightly regulated. As suppressor of cytokine signaling (SOCS) proteins effectively control immune responses, we investigated the role of SOCS2 in IL-1ß-induced DC activation. Human monocyte-derived DCs were stimulated with IL-1ß, and SOCS2 mRNA and protein levels were measured. DC activation was assessed by cytokine secretion and surface marker expression. For functional analysis, small interfering RNA (siRNA)-based SOCS2 silencing was performed. SOCS2 expression was also analyzed in a curated NCBI GEO dataset of myeloid leukemia patients. We found IL-1ß to be a potent inducer of SOCS2 expression. By silencing SOCS2, we showed that SOCS2 specifically limits IL-1ß-induced IL-8 secretion. Moreover, our analysis revealed that SOCS2 levels are significantly increased in patients with acute and chronic myeloid leukemia, two hematological malignancies where disease progression is closely linked to IL-1ß. This study identifies SOCS2 as a novel IL-1ß-inducible target gene and points toward a potential role of SOCS2 in IL-1ß-mediated DC activation.


Assuntos
Células Dendríticas/imunologia , Interleucina-1beta/farmacologia , Ativação Linfocitária/imunologia , Monócitos/imunologia , Proteínas Supressoras da Sinalização de Citocina/metabolismo , Diferenciação Celular , Células Cultivadas , Citocinas/metabolismo , Células Dendríticas/citologia , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Humanos , Ativação Linfocitária/efeitos dos fármacos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Transdução de Sinais , Proteínas Supressoras da Sinalização de Citocina/genética
17.
Cytokine Growth Factor Rev ; 43: 8-15, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30181021

RESUMO

Cytokines exert profound effects on the progression of hematopoietic malignancies such as acute myeloid leukemia (AML). Critical roles of cytokines in the context of inflammation have gained special interest. While pro-inflammatory mediators such as IL-1ß, TNF-α and IL-6 tend to increase AML aggressiveness, anti-inflammatory mediators such as TGF-ß and IL-10 appear to impede AML progression. Dysregulation of the complex interactions between pro- and anti-inflammatory cytokines in AML may create a pro-tumorigenic microenvironment with effects on leukemic cell proliferation, survival and drug-resistance. This article summarizes current knowledge about the functions of pro- and anti-inflammatory cytokines in AML, their modes of action, and therapeutic interventions with potential to improve clinical outcomes for AML patients.


Assuntos
Citocinas/imunologia , Mediadores da Inflamação/imunologia , Leucemia Mieloide Aguda/imunologia , Animais , Humanos , Linfócitos T/imunologia
18.
Hum Immunol ; 79(8): 610-615, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29886260

RESUMO

Dendritic cells play an important role in the initiation of immune reactions. Due to their high capacity to prime T-cell responses, the activation of dendritic cells must be tightly controlled. Because Interleukin-1ß (IL-1ß) is a key player in autoinflammatory diseases, we compared the ability of IL-1ß to activate human dendritic cells and induce immune-regulatory molecules versus the effects induced by pathogen-derived stimuli. Upon activation with either IL-1ß or microbial stimuli, monocyte-derived dendritic cells showed enhanced expression of costimulatory molecules, increased secretion of chemokines and cytokines, and the ability to activate T cells. In contrast, immune-feedback molecules, including PD-L1, IL-1RA, IL-10 and SOCS1, were exclusively upregulated in response to microbial stimuli, whereas IL-1ß treatment had no inducing effect on them. Thus, the limited capacity of IL-1ß to induce potential feedback inhibitors may support its key etiologic role in chronic inflammation and autoinflammatory responses.


Assuntos
Doenças Autoimunes/imunologia , Células Dendríticas/imunologia , Interleucina-1beta/metabolismo , Linfócitos T/imunologia , Antígeno B7-H1/genética , Antígeno B7-H1/metabolismo , Diferenciação Celular , Células Cultivadas , Técnicas de Cocultura , Regulação da Expressão Gênica , Humanos , Proteína Antagonista do Receptor de Interleucina 1/genética , Proteína Antagonista do Receptor de Interleucina 1/metabolismo , Interleucina-10/metabolismo , Lipopolissacarídeos/imunologia , Ativação Linfocitária , Proteína 1 Supressora da Sinalização de Citocina/genética , Proteína 1 Supressora da Sinalização de Citocina/metabolismo
20.
Nanotoxicology ; 11(9-10): 1157-1175, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29192556

RESUMO

Nanoparticles (NPs) are easily contaminated by bacterial endotoxin (lipopolysaccharide [LPS]). The presence of LPS can be responsible for many immune/inflammatory effects attributed to NPs. In this study, we examined the effects of LPS adsorption on the NP surface on the formation of a biocorona in biological fluids and on the subsequent inflammation-inducing activity of NPs. Different gold (Au) NPs with sizes ranging from 10 to 80 nm and with different surface functionalization (sodium citrate, lipoic acid, and branched polyethyleneimine (BPEI), or polyethylene glycol (PEG)) were exposed to E. coli LPS under different conditions. The binding capacity of LPS to the surface of AuNPs was dose- and time-dependent. LPS attached to sodium citrate and lipoic acid coatings, but did not adhere to BPEI- or PEG-coated NPs. By computational simulation, the binding of LPS to AuNPs seems to follow the Langmuir absorption isotherm. The presence of LPS on AuNP surface interfered and caused a decrease in the formation of the expected biomolecular corona upon incubation in human plasma. LPS-coated AuNPs, but not the LPS-free NPs, induced significant inflammatory responses in vitro. Notably, while free LPS did also induce an anti-inflammatory response, LPS bound to NPs appeared unable to do so. In conclusion, the unintentional adsorption of LPS onto the NP surface can affect the biocorona formation and the inflammatory properties of NPs. Thus, for an accurate interpretation of NP interactions with cells, it is extremely important to be able to distinguish the intrinsic NP biological effects from those caused by biologically active contaminants such as endotoxin.


Assuntos
Ouro/toxicidade , Lipopolissacarídeos/toxicidade , Nanopartículas Metálicas/toxicidade , Monócitos/efeitos dos fármacos , Coroa de Proteína/análise , Adsorção , Proteínas Sanguíneas/química , Biologia Computacional , Ouro/química , Células HEK293 , Humanos , Inflamação , Interleucina-1/biossíntese , Lipopolissacarídeos/química , Nanopartículas Metálicas/química , Modelos Biológicos , Monócitos/imunologia , Tamanho da Partícula , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...