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BACKGROUND: Atopic dermatitis is characterized by scratching and a TH2-dominated local and systemic response to cutaneously encountered antigens. Dendritic cells (DCs) capture antigens in the skin and rapidly migrate to draining lymph nodes (dLNs) where they drive the differentiation of antigen-specific naive T cells. OBJECTIVE: We sought to determine whether non-T-cell-derived IL-4 acts on skin-derived DCs to promote the TH2 response to cutaneously encountered antigen and allergic skin inflammation. METHODS: DCs from dLNs of ovalbumin (OVA)-exposed skin were analyzed by flow cytometry and for their ability to polarize OVA-specific naive CD4+ T cells. Skin inflammation following epicutaneous sensitization of tape-stripped skin was assessed by flow cytometry of skin cells and real-time quantitative PCR of cytokines. Cytokine secretion and antibody levels were evaluated by ELISA. RESULTS: Scratching upregulated IL4 expression in human skin. Similarly, tape stripping caused rapid basophil-dependent upregulation of cutaneous Il4 expression in mouse skin. In vitro treatment of DCs from skin dLNs with IL-4 promoted their capacity to drive TH2 differentiation. DCs from dLNs of OVA-sensitized skin of Il4-/- mice and CD11c-CreIl4rflox/- mice, which lack IL-4Rα expression in DCs (DCΔ/Δll4ra mice), were impaired in their capacity to drive TH2 polarization compared with DCs from controls. Importantly, OVA-sensitized DCΔ/Δll4ra mice demonstrated impaired allergic skin inflammation and OVA-specific systemic TH2 response evidenced by reduced TH2 cytokine secretion by OVA-stimulated splenocytes and lower levels of OVA-specific IgE and IgG1 antibodies, compared with controls. CONCLUSIONS: Mechanical skin injury causes basophil-dependent upregulation of cutaneous IL-4. IL-4 acts on skin DCs that capture antigen and migrate to dLNs to promote their capacity for TH2 polarization and drive allergic skin inflammation.
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BACKGROUND: Dedicator of cytokinesis 8 (DOCK8)-deficient patients have severe eczema, elevated IgE, and eosinophilia, features of atopic dermatitis (AD). OBJECTIVE: We sought to understand the mechanisms of eczema in DOCK8 deficiency. METHODS: Skin biopsy samples were characterized by histology, immunofluorescence microscopy, and gene expression. Skin barrier function was measured by transepidermal water loss. Allergic skin inflammation was elicited in mice by epicutaneous sensitization with ovalbumin (OVA) or cutaneous application of Staphylococcus aureus. RESULTS: Skin lesions of DOCK8-deficient patients exhibited type 2 inflammation, and the patients' skin was colonized by Saureus, as in AD. Unlike in AD, DOCK8-deficient patients had a reduced FOXP3:CD4 ratio in their skin lesions, and their skin barrier function was intrinsically intact. Dock8-/- mice exhibited reduced numbers of cutaneous T regulatory (Treg) cells and a normal skin barrier. Dock8-/- and mice with an inducible Dock8 deletion in Treg cells exhibited increased allergic skin inflammation after epicutaneous sensitization with OVA. DOCK8 was shown to be important for Treg cell stability at sites of allergic inflammation and for the generation, survival, and suppressive activity of inducible Treg cells. Adoptive transfer of wild-type, but not DOCK8-deficient, OVA-specific, inducible Treg cells suppressed allergic inflammation in OVA-sensitized skin of Dock8-/- mice. These mice developed severe allergic skin inflammation and elevated serum IgE levels after topical exposure to Saureus. Both were attenuated after adoptive transfer of WT but not DOCK8-deficient Treg cells. CONCLUSION: Treg cell dysfunction increases susceptibility to allergic skin inflammation in DOCK8 deficiency and synergizes with cutaneous exposure to Saureus to drive eczema in DOCK8 deficiency.
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Eccema , Factores de Intercambio de Guanina Nucleótido , Ratones Noqueados , Piel , Staphylococcus aureus , Linfocitos T Reguladores , Animales , Linfocitos T Reguladores/inmunología , Factores de Intercambio de Guanina Nucleótido/deficiencia , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/inmunología , Eccema/inmunología , Staphylococcus aureus/inmunología , Humanos , Ratones , Piel/inmunología , Piel/patología , Femenino , Masculino , Ratones Endogámicos C57BL , Dermatitis Atópica/inmunologíaRESUMEN
BACKGROUND: Atopic dermatitis (AD) is characterized by TH2-dominated skin inflammation and systemic response to cutaneously encountered antigens. The TH2 cytokines IL-4 and IL-13 play a critical role in the pathogenesis of AD. The Q576->R576 polymorphism in the IL-4 receptor alpha (IL-4Rα) chain common to IL-4 and IL-13 receptors alters IL-4 signaling and is associated with asthma severity. OBJECTIVE: We sought to investigate whether the IL-4Rα R576 polymorphism is associated with AD severity and exaggerates allergic skin inflammation in mice. METHODS: Nighttime itching interfering with sleep, Rajka-Langeland, and Eczema Area and Severity Index scores were used to assess AD severity. Allergic skin inflammation following epicutaneous sensitization of mice 1 or 2 IL-4Rα R576 alleles (QR and RR) and IL-4Rα Q576 (QQ) controls was assessed by flow cytometric analysis of cells and quantitative RT-PCR analysis of cytokines in skin. RESULTS: The frequency of nighttime itching in 190 asthmatic inner-city children with AD, as well as Rajka-Langeland and Eczema Area and Severity Index scores in 1116 White patients with AD enrolled in the Atopic Dermatitis Research Network, was higher in subjects with the IL-4Rα R576 polymorphism compared with those without, with statistical significance for the Rajka-Langeland score. Following epicutaneous sensitization of mice with ovalbumin or house dust mite, skin infiltration by CD4+ cells and eosinophils, cutaneous expression of Il4 and Il13, transepidermal water loss, antigen-specific IgE antibody levels, and IL-13 secretion by antigen-stimulated splenocytes were significantly higher in RR and QR mice compared with QQ controls. Bone marrow radiation chimeras demonstrated that both hematopoietic cells and stromal cells contribute to the mutants' exaggerated allergic skin inflammation. CONCLUSIONS: The IL-4Rα R576 polymorphism predisposes to more severe AD and increases allergic skin inflammation in mice.
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Dermatitis Atópica , Eccema , Ratones , Animales , Interleucina-13/genética , Interleucina-13/metabolismo , Interleucina-4/genética , Interleucina-4/metabolismo , Células Th2 , Piel/metabolismo , Citocinas/metabolismo , Inflamación/metabolismo , Prurito/metabolismo , Eccema/metabolismoRESUMEN
A visible-light photoredox-catalyzed method is reported that enables the coupling between benzylic C-H substrates and N-H azoles. Classically, medicinally relevant N-benzyl azoles are produced via harsh substitution conditions between the azole and a benzyl electrophile in the presence of strong bases at high temperatures. Use of C-H bonds as the alkylating partner streamlines the preparation of these important motifs. In this work, we report the use of N-alkoxypyridinium salts as a critically enabling reagent for the development of a general C(sp3)-H azolation. The platform enables the alkylation of electron-deficient, -neutral, and -rich azoles with a range of C-H bonds, most notably secondary and tertiary partners. Moreover, the protocol is mild enough to tolerate benzyl electrophiles, thus offering an orthogonal approach to existing SN2 and cross-coupling methods.
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DOCK8 deficient patients are susceptible to skin infection with Staphylococcus aureus which is normally cleared by neutrophils. We examined the mechanism of this susceptibility in mice. Dock8-/- mice had delayed clearance of S. aureus from skin mechanically injured by tape stripping. The numbers and viability of neutrophils in infected but not in uninfected, tape stripped skin were significantly reduced in Dock8-/- mice compared to WT controls. This is despite comparable numbers of circulating neutrophils, and normal to elevated cutaneous expression of Il17a and IL-17A inducible neutrophil attracting chemokines Cxcl1, Cxcl2 and Cxcl3. DOCK8 deficient neutrophils were significantly more susceptible to cell death upon in vitro exposure to S. aureus and exhibited reduced phagocytosis of S. aureus bioparticles but had a normal respiratory burst. Impaired neutrophil survival in infected skin and defective neutrophil phagocytosis likely underlie the susceptibility to cutaneous S. aureus infection in DOCK8 deficiency.
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Staphylococcus aureus Resistente a Meticilina , Enfermedades Cutáneas Infecciosas , Infecciones Estafilocócicas , Animales , Ratones , Neutrófilos/metabolismo , Staphylococcus aureus/fisiología , Piel , Ratones Endogámicos C57BL , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismoRESUMEN
BACKGROUND: Atopic dermatitis (AD) is characterized by a skin barrier defect aggravated by mechanical injury inflicted by scratching, a TH2 cell-dominated immune response, and susceptibility to viral skin infections that are normally restrained by a TH1 cell response. The signals leading to a TH2 cell-dominated immune response in AD are not completely understood. OBJECTIVE: Our aim was to determine the role of IL-13 in initiation of the TH cell response to cutaneously encountered antigens. METHODS: Wild-type, Il13-/-, Il1rl1-/-, and Il4ra-/- mice, as well as mice with selective deficiency of IL-13 in mast cells (MCs) were studied; in addition, dendritic cells (DCs) purified from the draining lymph nodes of tape-stripped and ovalbumin (OVA)-sensitized skin were examined for their ability to polarize naive OVA-TCR transgenic CD4+ T cells. Cytokine expression was examined by reverse-transcriptase quantitative PCR, intracellular flow cytometry, and ELISA. Contact hypersensitivity to dinitrofluorobenzene was examined. RESULTS: Tape stripping caused IL-33-driven upregulation of Il13 expression by skin MCs. MC-derived IL-13 acted on DCs from draining lymph nodes of OVA-sensitized skin to selectively suppress their ability to polarize naive OVA-TCR transgenic CD4+ T cells into IFN-γ-secreting cells. MC-derived IL-13 inhibited the TH1 cell response in contact hypersensitivity to dinitrofluorobenzene. IL-13 suppressed IL-12 production by mouse skin-derived DCs in vitro and in vivo. Scratching upregulated IL13 expression in human skin, and IL-13 suppressed the capacity of LPS-stimulated human skin DCs to express IL-12 and promote IFN-γ secretion by CD4+ T cells. CONCLUSION: Release of IL-13 by cutaneous MCs in response to mechanical skin injury inhibits the TH1 cell response to cutaneous antigen exposure in AD.
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Citocinas/biosíntesis , Dermatitis Atópica/inmunología , Dermatitis Atópica/metabolismo , Mastocitos/inmunología , Mastocitos/metabolismo , Células TH1/inmunología , Células TH1/metabolismo , Animales , Antígenos/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Humanos , Interleucina-12/metabolismo , Interleucina-13/biosíntesis , Ratones , Ratones Noqueados , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
Herein, we report on the synthesis of ultrasmall Pd nanoclusters (â¼2â nm) protected by L-cysteine [HOCOCH(NH2 )CH2 SH] ligands (Pdn (L-Cys)m ) and supported on the surfaces of CeO2 , TiO2 , Fe3 O4 , and ZnO nanoparticles for CO catalytic oxidation. The Pdn (L-Cys)m nanoclusters supported on the reducible metal oxides CeO2 , TiO2 and Fe3 O4 exhibit a remarkable catalytic activity towards CO oxidation, significantly higher than the reported Pd nanoparticle catalysts. The high catalytic activity of the ligand-protected clusters Pdn (L-Cys)m is observed on the three reducible oxides where 100 % CO conversion occurs at 93-110 °C. The high activity is attributed to the ligand-protected Pd nanoclusters where the L-cysteine ligands aid in achieving monodispersity of the Pd clusters by limiting the cluster size to the active sub-2-nm region and decreasing the tendency of the clusters for agglomeration. In the case of the ceria support, a complete removal of the L-cysteine ligands results in connected agglomerated Pd clusters which are less reactive than the ligand-protected clusters. However, for the TiO2 and Fe3 O4 supports, complete removal of the ligands from the Pdn (L-Cys)m clusters leads to a slight decrease in activity where the T100% CO conversion occurs at 99 °C and 107 °C, respectively. The high porosity of the TiO2 and Fe3 O4 supports appears to aid in efficient encapsulation of the bare Pdn nanoclusters within the mesoporous pores of the support.
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BACKGROUND: Key aspects of microbiome research are the accurate identification of taxa and the profiling of their functionality. Amplicon profiling based on the 16S ribosomal DNA sequence is a ubiquitous technique to identify and profile the abundance of the various taxa. However, it does not provide information on their encoded functionality. Predictive tools that can accurately extrapolate the functional information of a microbiome based on taxonomic profile composition are essential. At present, the applicability of these tools is limited due to requirement of reference genomes from known species. We present IPCO (Inference of Pathways from Co-variance analysis), a new method of inferring functionality for 16S-based microbiome profiles independent of reference genomes. IPCO utilises the biological co-variance observed between paired taxonomic and functional profiles and co-varies it with the queried dataset. RESULTS: IPCO outperforms other established methods both in terms of sample and feature profile prediction. Validation results confirmed that IPCO can replicate observed biological associations between shotgun and metabolite profiles. Comparative analysis of predicted functionality profiles with other popular 16S-based functional prediction tools showed significantly lower performances with predicted functionality showing little to no correlation with paired shotgun features across samples. CONCLUSIONS: IPCO can infer functionality from 16S datasets and significantly outperforms existing tools. IPCO is implemented in R and available from https://github.com/IPCO-Rlibrary/IPCO.
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Microbiota/genética , ARN Ribosómico 16S/genética , Programas Informáticos , Análisis de Varianza , Humanos , FilogeniaRESUMEN
Bacterial cold shock proteins (CSPs) function as RNA chaperones. To assess CSP's roles in the intracellular human pathogen Salmonella Typhimurium, we analyzed their expression in varied stress conditions. We found that cold shock protein E (cspE or STM14_0732) is up-regulated during bile salt-induced stress and that an S. Typhimurium strain lacking cspE (ΔcspE) displays dose-dependent sensitivity to bile salts, specifically to deoxycholate. We also found that an uncharacterized gene, yciF (STM14_2092), is up-regulated in response to bile stress in WT but not in the ΔcspE strain. Complementation with WT CspE, but not with a F30V CspE variant, abrogated the bile sensitivity of ΔcspE as did multicopy overexpression of yciF. Northern blotting experiments with rifampicin disclosed that the regulation of yciF expression is, most likely, due to the RNA-stabilizing activity of CspE. Importantly, electrophoretic mobility shift assays indicated that purified CspE, but not the F30V variant, directly binds yciF mRNA. We also observed that the extra-cytoplasmic stress-response (ESR) pathway is augmented in the bile-treated ΔcspE strain, as judged by induction of RpoE regulon genes (rpoE, degP, and rybB) and downstream ESR genes (hfq, rne, and PNPase). Moreover, the transcript levels of the porin genes, ompD, ompF, and ompC, were higher in bile salts-stressed ΔcspE and correlated with higher intracellular accumulation of the fluorescent DNA stain bisBenzimide H 33258, indicating greater cell permeability. In conclusion, our study has identified YciF, a CspE target involved in the regulation of porins and in countering bile stress in S. Typhimurium.
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Proteínas Bacterianas/metabolismo , Ácidos y Sales Biliares/farmacología , Proteínas y Péptidos de Choque por Frío/metabolismo , Proteínas de Choque Térmico/metabolismo , Salmonella typhimurium/metabolismo , Regulación hacia Arriba/efectos de los fármacos , Proteínas Bacterianas/genética , Proteínas y Péptidos de Choque por Frío/deficiencia , Proteínas y Péptidos de Choque por Frío/genética , Regulación Bacteriana de la Expresión Génica/efectos de los fármacos , Proteínas de Choque Térmico/genética , Mutagénesis Sitio-Dirigida , Permeabilidad/efectos de los fármacos , Porinas/metabolismo , ARN Mensajero/metabolismo , Rifampin/química , Salmonella typhimurium/efectos de los fármacosRESUMEN
An efficient palladium(ii) mediated C-glycosylation of glycals with diaryliodonium salts is described, providing a new strategy for the synthesis of 2,3-dideoxy C-aryl glycosides with excellent stereoselectivity. The C-glycosylation of a diverse range of glycals, including d-glucal, d-galactal, d-allal, l-rhamnal, l-fucal, l-arabinal, d-maltal, and d-lactal, occurred effectively and the corresponding C-glycosides were obtained in moderate to good yields. This protocol is commended as a significant addition to the field of carbohydrate chemistry due to the rich functional group compatibility, broad range of substrate scope and exceptional α-stereoselectivity.
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Éteres Cíclicos/química , Glicósidos/síntesis química , Paladio/química , Catálisis , Glicósidos/química , Glicosilación , Polisacáridos/química , Sales (Química)/química , EstereoisomerismoRESUMEN
BACKGROUND: Therapeutic normal IgG or intravenous immunoglobulin (IVIG) exerts anti-inflammatory effects through several mutually nonexclusive mechanisms. Recent data in mouse models of autoimmune disease suggest that IVIG induces IL-4 in basophils by enhancing IL-33 in SIGN-related 1-positive innate cells. However, translational insight on these data is lacking. OBJECTIVE: We sought to investigate the effect of IVIG on human basophil functions. METHODS: Isolated circulating basophils from healthy donors were cultured in the presence of IL-3, IL-33, GM-CSF, thymic stromal lymphopoietin, or IL-25. The effect of IVIG and F(ab')2 and Fc IVIG fragments was examined based on expression of various surface molecules, phosphorylation of spleen tyrosine kinase, induction of cytokines, and histamine release. Basophil phenotypes were also analyzed from IVIG-treated patients with myopathy. Approaches, such as depletion of anti-IgE reactivity from IVIG, blocking antibodies, or inhibitors, were used to investigate the mechanisms. RESULTS: We report that IVIG directly induces activation of IL-3-primed human basophils, but IL-33 and other cytokines were dispensable for this effect. Activation of basophils by IVIG led to enhanced expression of CD69 and secretion of IL-4, IL-6, and IL-8. IVIG-treated patients with myopathy displayed enhanced expression of CD69 on basophils. The spleen tyrosine kinase pathway is implicated in these functions of IVIG and were mediated by F(ab')2 fragments. Mechanistically, IVIG induced IL-4 in human basophils by interacting with basophil surface-bound IgE but independent of FcγRII, type II Fc receptors, C-type lectin receptors, and sialic acid-binding immunoglobulin-like lectins. CONCLUSION: These results uncovered a pathway of promoting the TH2 response by IVIG through direct interaction of IgG with human basophils.
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Antiinflamatorios/farmacología , Basófilos/inmunología , Fragmentos Fc de Inmunoglobulinas/farmacología , Inmunoglobulinas Intravenosas/farmacología , Animales , Antígenos CD/metabolismo , Antígenos de Diferenciación de Linfocitos T/metabolismo , Basófilos/efectos de los fármacos , Células Cultivadas , Modelos Animales de Enfermedad , Liberación de Histamina , Humanos , Inmunoglobulina E/metabolismo , Interleucina-3/metabolismo , Lectinas Tipo C/metabolismo , Ratones , Quinasa Syk/metabolismo , Regulación hacia ArribaRESUMEN
Basophils are rare granulocytes and dysregulated functions of these cells are associated with several atopic and non-atopic allergic diseases of skin, respiratory system and gastrointestinal tract. Both cytokines and immunoglobulin E (IgE) are implicated in mediating the basophil activation and pathogenesis of these disorders. Several reports have shown that healthy individuals, and patients with allergic disorders display IgG autoantibodies to IgE and hence functional characterization of these anti-IgE IgG autoantibodies is critical. In general, anti-IgE IgG autoantibodies modulate basophil activation irrespective of allergen specificity by interacting with constant domains of IgE. Therefore, an ideal solution to prove the functions of such anti-IgE IgG autoantibodies would be to completely eliminate type I high affinity immunoglobulin E receptor (FcÉRI)-bound IgE from the surface of basophils and to demonstrate in an unequivocal manner the role of anti-IgE IgG autoantibodies. In line with previous reports, our data show that FcÉRI on peripheral blood basophils are almost saturated with IgE. Further, acetic acid buffer (pH 4) efficiently removes these FcÉRI-bound IgE. Although immediately following acetic acid-elution of IgE had no repercussion on the viability of basophils, following 24 hours culture with interleukin-3 (IL-3), the viability and yield of basophils were drastically reduced in acid-treated cells and had repercussion on the induction of activation markers. Lactic acid treatment on the other hand though had no adverse effects on the viability of basophils and IL-3-induced activation, it removed only a small fraction of the cell surface bound IgE. Thus, our results show that acid buffers could be used for the elution of FcÉRI-bound IgE on the basophil surface for the biochemical characterization of IgE antibodies or for the immediate use of basophils to determine their sensitivity to undergo degranulation by specific allergens. However, these methods are not utile for the functional assays of basophils that require longer duration of culture and entire removal of surface IgE to validate the role of anti-IgE IgG autoantibodies that interact with FcÉRI-bound IgE irrespective of allergen specificity.
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Ácido Acético , Basófilos , Bioensayo , Inmunoglobulina E , Receptores de IgE/inmunología , Ácido Acético/química , Ácido Acético/farmacología , Basófilos/química , Basófilos/inmunología , Técnicas de Cultivo de Célula , Humanos , Inmunoglobulina E/química , Inmunoglobulina E/inmunologíaRESUMEN
OBJECTIVE: To investigate compositional differences in the gut microbiota associated with bone homeostasis and fractures in a cohort of older adults. METHODS: Faecal microbiota profiles were determined from 181 individuals with osteopenia (n = 61) or osteoporosis (n = 60), and an age- and gender-matched group with normal BMD (n = 60). Analysis of the 16S (V3-V4 region) amplicon dataset classified to the genus level was used to identify significantly differentially abundant taxa. Adjustments were made for potential confounding variables identified from the literature using several statistical models. RESULTS: We identified six genera that were significantly altered in abundance in the osteoporosis or osteopenic groups compared with age- and gender-matched controls. A detailed study of microbiota associations with meta-data variables that included BMI, health status, diet and medication revealed that these meta-data explained 15-17% of the variance within the microbiota dataset. BMD measurements were significantly associated with alterations in the microbiota. After controlling for known biological confounders, five of the six taxa remained significant. Overall microbiota alpha diversity did not correlate to BMD in this study. CONCLUSION: Reduced BMD in osteopenia and osteoporosis is associated with an altered microbiota. These alterations may be useful as biomarkers or therapeutic targets in individuals at high risk of reductions in BMD. These observations will lead to a better understanding of the relationship between the microbiota and bone homeostasis.
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Densidad Ósea/fisiología , Microbioma Gastrointestinal/fisiología , Tracto Gastrointestinal/microbiología , Estado de Salud , Osteoporosis/metabolismo , Fracturas Osteoporóticas/metabolismo , Absorciometría de Fotón/métodos , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/diagnóstico , Osteoporosis/microbiología , Fracturas Osteoporóticas/diagnóstico , Fracturas Osteoporóticas/microbiologíaRESUMEN
The authors wish to make the following corrections to this paper [...].
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Background: Human dendritic cell (DC) response to α-(1,3)-glucan polysaccharide of Aspergillus fumigatus and ensuing CD4+ T-cell polarization are poorly characterized. Methods: α-(1,3)-Glucan was isolated from A. fumigatus conidia and mycelia cell wall. For the analysis of polarization, DCs and autologous naive CD4+ T cells were cocultured. Phenotype of immune cells was analyzed by flow cytometry, and cytokines by enzyme-linked immunosorbent assay (ELISA). Blocking antibodies were used to dissect the role of Toll-like receptor 2 (TLR2) and programmed death-ligand 1 (PD-L1) in regulating α-(1,3)-glucan-mediated DC activation and T-cell responses. DCs from TLR2-deficient mice were additionally used to consolidate the findings. Results: α-(1,3)-Glucan induced the maturation of DCs and was dependent in part on TLR2. "α-(1,3)-Glucan-educated" DCs stimulated the activation of naive T cells and polarized a subset of these cells into CD4+CD25+FoxP3+ regulatory T cells (Tregs). Mechanistically, Treg stimulation by α-(1,3)-glucan was dependent on the PD-L1 pathway that negatively regulated interferon-gamma (IFN-γ) secretion. Short α-(1,3)-oligosaccharides lacked the capacity to induce maturation of DCs but significantly blocked α-(1,3)-glucan-induced Treg polarization. Conclusions: PD-L1 dictates the balance between Treg and IFN-γ responses induced by α-(1,3)-glucan. Our data provide a rationale for the exploitation of immunotherapeutic approaches that target PD-1-PD-L1 to enhance protective immune responses to A. fumigatus infections.
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Aspergillus fumigatus/inmunología , Antígeno B7-H1/genética , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Expresión Génica , Glucanos/inmunología , Activación de Linfocitos/inmunología , Linfocitos T Reguladores/inmunología , Animales , Biomarcadores , Citocinas/metabolismo , Humanos , Interferón gamma/metabolismo , Ratones , Ratones Noqueados , Linfocitos T Colaboradores-Inductores/inmunología , Linfocitos T Colaboradores-Inductores/metabolismo , Linfocitos T Reguladores/metabolismoRESUMEN
BACKGROUND: Intravenous immunoglobulin (IVIG) is a polyspecific pooled immunoglobulin G preparation and one of the commonly used therapeutics for autoimmune diseases including those of neurological origin. A recent report in murine model proposed that IVIG expands regulatory T (Treg) cells via induction of interleukin 33 (IL-33). However, translational insight on these observations is lacking. METHODS: Ten newly diagnosed Guillain-Barré syndrome (GBS) patients were treated with IVIG at the rate of 0.4 g/kg for three to five consecutive days. Clinical evaluation for muscular weakness was performed by Medical Research Council (MRC) and modified Rankin scoring (MRS) system. Heparinized blood samples were collected before and 1, 2, and 4-5 weeks post-IVIG therapy. Peripheral blood mononuclear cells were stained for surface CD4 and intracellular Foxp3, IFN-γ, and tumor necrosis factor alpha (TNF-α) and were analyzed by flow cytometry. IL-33 and prostaglandin E2 in the plasma were measured by ELISA. RESULTS: The fold changes in plasma IL-33 at week 1 showed no correlation with the MRC and MRS scores at weeks 1, 2, and ≥4 post-IVIG therapy. Clinical recovery following IVIG therapy appears to be associated with Treg cell response. Contrary to murine study, there was no association between the fold changes in IL-33 at week 1 and Treg cell frequency at weeks 1, 2, and ≥4 post-IVIG therapy. Treg cell-mediated clinical response to IVIG therapy in GBS patients was associated with reciprocal regulation of effector T cells-expressing TNF-α. CONCLUSION: Treg cell expansion by IVIG in patients with autoimmune diseases lack correlation with IL-33. Treg cell frequency, but not plasma IL-33 levels, represents potential immunological biomarker to predict clinical response to IVIG therapy.
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Síndrome de Guillain-Barré , Inmunoglobulinas Intravenosas/uso terapéutico , Factores Inmunológicos/uso terapéutico , Interleucina-33/sangre , Linfocitos T Reguladores/patología , Anciano , Anciano de 80 o más Años , Dinoprostona/metabolismo , Ensayo de Inmunoadsorción Enzimática , Femenino , Citometría de Flujo , Estudios de Seguimiento , Síndrome de Guillain-Barré/sangre , Síndrome de Guillain-Barré/tratamiento farmacológico , Síndrome de Guillain-Barré/patología , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Valor Predictivo de las Pruebas , Índice de Severidad de la Enfermedad , Estadísticas no ParamétricasRESUMEN
The development of methods for carbon-carbon bond formation under benign conditions is an ongoing challenge for synthetic chemists. In recent years there has been considerable interest in using selective C-H activation as a direct route for generating reactive intermediates. Herein, the use of visible-light-mediated dual photoredox organocatalysis as a mild and effective method for Csp2 -H activation of aldehydes is reported, resulting in the generation of acyl radicals. These nucleophilic acyl radical species can undergo either addition to electrophilic alkenes or nickel-catalyzed cross-coupling reactions to provide a quick access to broad range of unsymmetrical ketones, which are abundantly found in many organic building blocks.
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The cellular proteolytic machinery orchestrates protein turnover and regulates several key biological processes. This study addresses the roles of Lon, a major ATP-dependent protease, in modulating the responses of Escherichia coli strain MG1655 to low and high amounts of sodium salicyclate (NaSal), a widely used clinically relevant analgesic. NaSal affects several bacterial responses, including growth and resistance to multiple antibiotics. The loss of lon reduces growth in response to high, but not low, amounts of NaSal. From amongst a panel of Lon substrates, MarA was identified to be the downstream target of Lon. Thus, stabilization of MarA in the absence of lon lowers growth of the strain in the presence of higher amounts of NaSal. The steady-state transcript levels of marA and its target genes, acrA, acrB and tolC, are higher in the Δlon strain compared with the WT strain. Consequently, the resistance to antibiotics, e.g. tetracycline and nalidixic acid, is enhanced in Δlon in a marA-dependent manner. Furthermore, the target genes of MarA, i.e. acrB and tolC, are responsible for NaSal-mediated antibiotic resistance. Studies using atomic force microscopy demonstrated that ciprofloxacin led to greater cell filamentation, which is lower in the Δlon strain due to higher levels of MarA. Overall, this study delineates the roles of Lon protease, its substrate MarA and downstream targets of MarA, e.g. acrB and tolC, during NaSal-mediated growth reduction and antibiotic resistance. The implications of these observations in the adaptation of E. coli under different environmental conditions are discussed.
Asunto(s)
Proteínas de Unión al ADN/metabolismo , Farmacorresistencia Bacteriana Múltiple/genética , Proteínas de Escherichia coli/metabolismo , Escherichia coli/crecimiento & desarrollo , Proteasa La/metabolismo , Salicilato de Sodio/farmacología , Antibacterianos/farmacología , Proteínas de la Membrana Bacteriana Externa/genética , Ciprofloxacina/farmacología , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Lipoproteínas/genética , Proteínas de Transporte de Membrana/genética , Pruebas de Sensibilidad Microbiana , Microscopía de Fuerza Atómica , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Ácido Nalidíxico/farmacología , Proteasa La/genética , Salicilato de Sodio/metabolismo , Tetraciclina/farmacología , Resistencia a la Tetraciclina/genéticaRESUMEN
Extracts of Viscum album (VA); a semi-parasitic plant, are frequently used in the complementary therapy of cancer and other immunological disorders. Various reports show that VA modulates immune system and exerts immune-adjuvant activities that might influence tumor regression. Currently, several therapeutic preparations of VA are available and hence an insight into the mechanisms of action of different VA preparations is necessary. In the present study, we performed a comparative study of five different preparations of VA on maturation and activation of human dendritic cells (DCs) and ensuing CD4⺠T cell responses. Monocyte-derived human DCs were treated with VA Qu Spez, VA Qu Frf, VA M Spez, VA P and VA A. Among the five VA preparations tested VA Qu Spez, a fermented extract with a high level of lectins, significantly induced DC maturation markers CD83, CD40, HLA-DR and CD86, and secretion of pro-inflammatory cytokines such as IL-6, IL-8, IL-12 and TNF-α. Furthermore, analysis of T cell cytokines in DC-T cell co-culture revealed that VA Qu Spez significantly stimulated IFN-γ secretion without modulating regulatory T cells and other CD4⺠T cytokines IL-4, IL-13 and IL-17A. Our study thus delineates differential effects of VA preparations on DC maturation; function and T cell responses.