interleukin-8 and Aspergillosis

Aspergillosis is a common cause of morbidity and mortality in immunocompromised populations. PU.1 is critical for innate immunity against Aspergillus fumigatus (AF) in macrophages. However, the molecular mechanism underlying PU.1 mediating immunity against AF infection in human alveolar macrophages (AMs) is still unclear.. In this study, we detected the expressions of PU.1, CD23, p-ERK, CCL20 and IL-8 and key inflammatory markers IL-1β, IL-6, TNF-α and IL-12 in human THP-1-derived macrophages (HTMs) or PU.1/CD23-overexpressed immunodeficient mice with AF infection. Moreover, we examined these expressions in PU.1-overexpressed/interfered HTMs. Additionally, we detected the phagocytosis of macrophages against AF infection with altered PU.1 expression. Dual luciferase, ChIP and EMSAs were performed to detect the interaction of PU.1 and CD23. And we invested the histological changes in mouse lung tissues transfected with PU.1/CD23-expressing adenoviruses in AF infection.. The results showed that the expressions of PU.1, CD23, p-ERK, CCL20, IL-8, IL-1β, IL-6, TNF-α and IL-12 increased significantly with AF infection, and PU.1 regulated the later 8 gene expressions in HTMs. Moreover, CD23 was directly activated by PU.1, and overexpression of CD23 in PU.1-interfered HTMs upregulated IL-1β, IL-6, TNF-α and IL-12 levels which were downregulated by PU.1 interference. PU.1 overexpression strengthened the phagocytosis of the HTMs against AF. And injection of PU.1/CD23-expressing adenoviruses attenuated pathological defects in immunodeficient mouse lung tissues with AF infection. Adenovirus (Ad)-PU.1 increased the CD23, p-ERK, CCL20, IL-8 levels.. Our study concluded that PU.1-CD23 signaling mediates innate immunity against AF in lungs through regulating inflammatory response. Therefore, PU.1-CD23 may be a new anti-aspergillosis therapeutic for the treatment of invasive aspergillosis with the deepening of gene therapy and its wide application in the clinic.

Topics: Animals; Aspergillosis; Aspergillus fumigatus; Humans; Immunity, Innate; Interleukin-12; Interleukin-6; Interleukin-8; Lung; Mice; Tumor Necrosis Factor-alpha

Human cytomegalovirus (CMV) is associated with aspergillosis, but the simultaneous presence of CMV viral interleukin-10 (cmvIL-10) and aspergillosis has never been investigated. CmvIL-10 is produced by CMV-infected cells and acts as an immune modulator during CMV infection. The aim of this study was to evaluate cmvIL-10 levels in peripheral blood and its influence on the clinical outcomes of Aspergillus infection.. Patients who visited or were admitted to the hospital with suspected Aspergillus infection, including invasive aspergillosis (IA) and chronic pulmonary aspergillosis (CPA), were prospectively enrolled. The cmvIL-10, human IL-10 (hIL-10), IL-1B, IL-6, IL-8, IFN-γ, and TNF-α levels in peripheral blood were measured.. Patients with Aspergillus infection had a higher level of cmvIL-10 than the control group (158 ± 305 vs 27.9 ± 30.4 pg/ml, p < .05). The level of cmvIL-10 was not correlated with CMV viremia or end-organ disease. The cmvIL-10 but not hIL-10 level was positively correlated with the IFN-γ level (p < .05) and marginally negatively correlated with IL-1B and IL-8 levels (p < .1). In patients with CPA, a high level of cmvIL-10 (≥100 pg/ml) was a poor prognostic factor for long-term survival (p < .05). In contrast, CMV viremia or end-organ disease was associated with poor survival in patients with IA (p = .05).. Aspergillus infection was associated with CMV coinfection with cmvIL-10 in blood. A cmvIL-10 concentration ≥100 pg/ml was a predictor for unfavourable outcome in CPA patients.

Topics: Aspergillosis; Cytomegalovirus; Cytomegalovirus Infections; Humans; Interleukin-10; Interleukin-8; Viral Proteins; Viremia

Dimethyl itaconate (DI) is a membrane-permeable itaconate derivative with anti-inflammatory functions. However, the anti-inflammatory effect of DI has never been studied in fungal keratitis. In this study, we tested the protective effect of DI against fungal keratitis and assessed the role of NF-E2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) signaling in this process. Eyes of C57BL/6 (B6) mice were treated with 2 mm DI after infection with Aspergillus fumigatus. Human corneal epithelial cells (HCECs) were pretreated with 0.25 mm DI and then incubated with A. fumigatus. Clinical scoring, slit-lamp photography, myeloperoxidase determination, flow cytometry and immunostaining were used to assess the disease response and treatment efficacy. PCR, Western blot and ELISA were used to assess the expression of interleukin-1β (IL-1β), chemokine (C-X-C motif) ligand 1, IL-6, IL-8, Nrf2 and HO-1. In addition, quantification of viable fungi, absorbance assays and fluorimetry were used to measure DI fungistatic activity. We observed that DI-treated eyes showed decreased clinical scores, fungal loads, polymorphonuclear neutrophil (PMN) infiltration and cytokine expression, compared with phosphate-buffered saline-treated infected eyes. DI treatment decreased the cytokine levels in infected corneas and in HCECs stimulated with A. fumigatus. Moreover, DI treatment increased Nrf2 and HO-1 expression in corneas and nuclear Nrf2 accumulation in HCECs. DI-induced cytokine downregulation was inhibited by pretreatment with an Nrf2 or HO-1 inhibitor. Finally, DI treatment reduced the A. fumigatus absorbance and fungal mass. These data indicate that DI protects against fungal keratitis by limiting inflammation via the Nrf2/HO-1 signaling pathway and that DI inhibits the growth of A. fumigatus.

Topics: Animals; Aspergillosis; Aspergillus fumigatus; Chemokine CXCL1; Cornea; Epithelial Cells; Epithelium, Corneal; Heme Oxygenase-1; Humans; Inflammation; Interleukin-6; Interleukin-8; Keratitis; Mice; NF-E2-Related Factor 2; Signal Transduction; Succinates

We previously showed that each dog with chronic non-invasive sino-nasal aspergillosis (SNA) was infected with a single genotype of Aspergillus fumigatus. Here, we studied the transcriptome of this fungal pathogen and the canine host within the biofilm resulting from the infection. We describe here transcriptomes resulting from natural infections in animal species with A. fumigatus. The host transcriptome showed high expression of IL-8 and alarmins, uncontrolled inflammatory reaction and dysregulation of the Th17 response. The fungal transcriptome showed in particular expression of genes involved in secondary metabolites and nutrient acquisition. Single-nucleotide polymorphism analysis of fungal isolates from the biofilms showed large genetic variability and changes related with adaptation to host environmental factors. This was accompanied with large phenotypic variability in in vitro stress assays, even between isolates from the same canine patient. Our analysis provides insights in genetic and phenotypic variability of Aspergillus fumigatus in biofilms of naturally infected dogs reflecting in-host adaptation. Absence of a Th17 response and dampening of the Th1 response contributes to the formation of a chronic sino-nasal warzone.

Topics: Alarmins; Animals; Aspergillosis; Aspergillus fumigatus; Biofilms; Dog Diseases; Dogs; Fungal Proteins; Gene Expression Profiling; Gene Expression Regulation; Gene Regulatory Networks; Interleukin-8; Polymorphism, Single Nucleotide; Sequence Analysis, RNA; Th17 Cells; Whole Genome Sequencing

Topics: Animals; Aspergillosis; Aspergillus fumigatus; Cells, Cultured; Fungal Polysaccharides; Humans; Immunity, Innate; Inflammation; Interleukin-8; Lung; Mice; Mice, Inbred C57BL; Mice, Knockout; Mucins; Protein Binding; Receptors, Cell Surface; Respiratory Mucosa

Topics: Aspergillosis; Aspergillus fumigatus; beta-Glucans; Complement Activation; Epithelial Cells; Ficolins; Fungal Polysaccharides; Humans; Interleukin-8; Lectins; Lung; Protein Binding

To observe the production mechanism of surfactant protein D (SP-D) in human corneal epithelial cells (HCECs) when infected by Aspergillus fumigatus (A. fumigatus) hyphae, and explore whether SP-D can inhibit the cell activations through toll-like receptor 4 signaling pathway during fungal infection.. mRNA and protein expressions of SP-D were evaluated in HCECs after stimulation by A. fumigatus, with or without pretreatment of TLR4 inhibitor (CLI-095) by real time PCR and Western blot. The expression levels of inflammatory cytokines IL-1β and IL-8 evaluated when pretreated with SP-D antibody or recombinant human SP-D in fungi-stimulated HCECs by real time PCR and ELISA, IL-1β and IL-8 expressions were also detected in A. fumigatus-stimulated HCECs that pretreated with CLI095 or MyD88 inhibitor (Pepinh-MYD) and recombinant human SP-D.. mRNA and protein levels of SP-D increased after stimulation of A. fumigatus for 16h and 20h respectively. The upregulation of SP-D could be inhibited by CLI-095. mRNA and protein expressions of IL-1β and IL-8 decreased significantly when pretreated HCECs with recombinant human SP-D for 4h before A. fumigatus stimulation, while IL-1β and IL-8 increased when pretreated with SP-D antibody for 1h. Pretreatment of CLI095 or Pepinh-MYD can increase the expressions of IL-1β and IL-8 mRNA and protein in HCECs induced by recombinant human SP-D and A. fumigatus.. SP-D can be stimulated by TLR4 during A. fumigatus infection. Recombinant human SP-D can inhibit the expression of inflammatory cytokines through TLR4 signaling pathway.

Topics: Aspergillosis; Aspergillus fumigatus; Cells, Cultured; Epithelial Cells; Epithelium, Corneal; Humans; Immunosuppressive Agents; Interleukin-1beta; Interleukin-8; Myeloid Differentiation Factor 88; Pulmonary Surfactant-Associated Protein D; Recombinant Proteins; Signal Transduction; Sulfonamides; Toll-Like Receptor 4

Recent studies suggest that immune-modulating single-nucleotide polymorphisms (SNPs) influence the risk of developing cancer-related infections. Here, we evaluated whether 36 SNPs within 14 immune-related genes are associated with the risk of invasive aspergillosis (IA) and whether genotyping of these variants might improve disease risk prediction. We conducted a case-control association study of 781 immunocompromised patients, 149 of whom were diagnosed with IA. Association analysis showed that the IL4Rrs2107356 and IL8rs2227307 SNPs (using dbSNP numbering) were associated with an increased risk of IA (IL4Rrs2107356 odds ratio [OR], 1.92; 95% confidence interval [CI], 1.20 to 3.09; IL8rs2227307 OR, 1.73; 95% CI, 1.06 to 2.81), whereas the IL12Brs3212227 and IFNγrs2069705 variants were significantly associated with a decreased risk of developing the infection (IL12Brs3212227 OR, 0.60; 95% CI, 0.38 to 0.96; IFNγrs2069705 OR, 0.63; 95% CI, 0.41 to 0.97). An allogeneic hematopoietic stem cell transplantation (allo-HSCT)-stratified analysis revealed that the effect observed for the IL4Rrs2107356 and IFNγrs2069705 SNPs was stronger in allo-HSCT (IL4Rrs2107356 OR, 5.63; 95% CI, 1.20 to 3.09; IFNγrs2069705 OR, 0.24; 95% CI, 0.10 to 0.59) than in non-HSCT patients, suggesting that the presence of these SNPs renders patients more vulnerable to infection, especially under severe and prolonged immunosuppressive conditions. Importantly, in vitro studies revealed that carriers of the IFNγrs2069705C allele showed a significantly increased macrophage-mediated neutralization of fungal conidia (P = 0.0003) and, under stimulation conditions, produced higher levels of gamma interferon (IFNγ) mRNA (P = 0.049) and IFNγ and tumor necrosis factor alpha (TNF-α) cytokines (P value for 96 h of treatment with lipopolysaccharide [PLPS-96 h], 0.057; P value for 96 h of treatment with phytohemagglutinin [PPHA-96 h], 0.036; PLPS+PHA-96 h = 0.030; PPHA-72 h = 0.045; PLPS+PHA-72 h = 0.018; PLPS-96 h = 0.058; PLPS+PHA-96 h = 0.0058). Finally, we also observed that the addition of SNPs significantly associated with IA to a model including clinical variables led to a substantial improvement in the discriminatory ability to predict disease (area under the concentration-time curve [AUC] of 0.659 versus AUC of 0.564; P-2 log likehood ratio test = 5.2 · 10(-4) and P50.000 permutation test = 9.34 · 10(-5)). These findings suggest that the IFNγrs2069705 SNP influences the risk of IA and that pred

Topics: Adult; Aged; Alleles; Aspergillosis; Case-Control Studies; Female; Genetic Predisposition to Disease; Genotype; Humans; Immunocompromised Host; Interferon-gamma; Interleukin-12 Subunit p40; Interleukin-4 Receptor alpha Subunit; Interleukin-8; Male; Middle Aged; Polymorphism, Single Nucleotide

The long pentraxin 3 (PTX3) has been shown to be important in maintaining internal tissue homeostasis and in protecting against fungal Aspergillus fumigatus infection. However, the molecular mechanisms of how these functions are elicited are poorly delineated. Ficolin-1 is a soluble pattern recognition molecule that interacts with PTX3. We hypothesized that heterocomplexes between ficolin-1 and PTX3 might mediate the signals necessary for sequestration of altered self-cells and A. fumigatus. We were able to show that ficolin-1 interacts with PTX3 via its fibrinogen-like domain. The interaction was affected in a pH- and divalent cation-sensitive manner. The primary binding site for ficolin-1 on PTX3 was located in the N-terminal domain portion of PTX3. Ficolin-1 and PTX3 heterocomplex formation occurred on dying host cells, but not on A. fumigatus. The heterocomplex formation was a prerequisite for enhancement of phagocytosis by human monocyte-derived macrophages and downregulation of IL-8 production during phagocytosis. On A. fumigatus, PTX3 exposed the C-terminal portion of the molecule, probably resulting in steric hindrance of ficolin-1 interaction with PTX3. These results demonstrate that ficolin-1 and PTX3 heterocomplex formation acts as a noninflammatory "find me and eat me" signal to sequester altered-host cells. The fact that the ficolin-1-PTX3 complex formation did not occur on A. fumigatus shows that PTX3 uses different molecular effector mechanisms, depending on which domains it exposes during ligand interaction.

Topics: Apoptosis; Aspergillosis; Aspergillus fumigatus; Binding Sites; C-Reactive Protein; Cells, Cultured; Ficolins; Humans; Interleukin-8; Lectins; Leukocytes, Mononuclear; Macrophages; Phagocytosis; Protein Binding; Protein Interaction Domains and Motifs; Protein Structure, Tertiary; Serum Amyloid P-Component; Signal Transduction; Surface Plasmon Resonance

Aspergillus fumigatus is an important allergen and opportunistic pathogen. Similarly to many other pathogens, it is able to produce lectins that may be involved in the host-pathogen interaction. We focused on the lectin AFL, which was prepared in recombinant form and characterized. Its binding properties were studied using hemagglutination and glycan array analysis. We determined the specificity of the lectin towards l-fucose and fucosylated oligosaccharides, including α1-6 linked core-fucose, which is an important marker for cancerogenesis. Other biologically relevant saccharides such as sialic acid, d-mannose or d-galactose were not bound. Blood group epitopes of the ABH and Lewis systems were recognized, Le(Y) being the preferred ligand among others. To provide a correlation between the observed functional characteristics and structural basis, AFL was crystallized in a complex with methyl-α,L-selenofucoside and its structure was solved using the SAD method. Six binding sites, each with different compositions, were identified per monomer and significant differences from the homologous AAL lectin were found. Structure-derived peptides were utilized to prepare anti-AFL polyclonal antibodies, which suggested the presence of AFL on the Aspergillus' conidia, confirming its expression in vivo. Stimulation of human bronchial cells by AFL led to IL-8 production in a dose-dependent manner. AFL thus probably contributes to the inflammatory response observed upon the exposure of a patient to A. fumigatus. The combination of affinity to human epithelial epitopes, production by conidia and pro-inflammatory activity is remarkable and shows that AFL might be an important virulence factor involved in an early stage of A. fumigatus infection.

Topics: Amino Acid Sequence; Aspergillosis; Aspergillus fumigatus; Binding Sites; Bronchi; Epitopes; Fucose; Galactose; Genome, Fungal; Hemagglutination; Host-Pathogen Interactions; Humans; Interleukin-8; Lectins; Mannose; Molecular Sequence Data; N-Acetylneuraminic Acid; Oligosaccharides; Sequence Alignment; Sequence Homology, Amino Acid; Spores, Fungal; Virulence Factors

Airway epithelial cells are the first cells to be challenged upon contact with the conidia of Aspergillus. In response, they express pattern-recognition receptors that play fundamental roles as sentinels and mediators of pulmonary innate immunity. The C-type lectin Dectin-1 is expressed predominantly on the surface of myeloid lineage cells. We examined the induction, regulation, and functions of Dectin-1 in pulmonary epithelial cells by challenging human bronchial epithelial (HBE) cells with A. fumigatus. Inflammatory, antimicrobial peptide genes and reactive oxygen species (ROS) were quantified, with and without knockdown of Dectin-1. We found that A. fumigatus induced the expression of Dectin-1 mRNA and protein in HBE cells in a toll-like receptor (TLR) 2-dependent manner. In addition, A. fumigatus-mediated generation of ROS was dependent on the upregulation of Dectin-1. Moreover, A. fumigatus actively induced the expression of TNFα, GM-CSF, IL8, HBD2, and HBD9. Knockdown of Dectin-1 inhibited TNFα, IL8, HBD2, and HBD9 expression. Hence, Dectin-1 was required for the upregulation of pro-inflammatory cytokines and antimicrobial peptides. Finally, knockdown of TLR2 significantly inhibited Dectin-1 upregulation. Our results demonstrate the novel induction of Dectin-1 in human bronchial epithelial cells and its critical role in the innate immune response against A. fumigatus in non-phagocytic cells.

Topics: Aspergillosis; Aspergillus fumigatus; beta-Defensins; Bronchi; Bronchial Provocation Tests; Cell Line, Tumor; Epithelial Cells; Flow Cytometry; Gene Expression Regulation; Gene Knockdown Techniques; Glucans; Humans; Immunity, Innate; Interleukin-8; Lectins, C-Type; Microscopy, Fluorescence; Polysaccharides; Reactive Oxygen Species; RNA, Messenger; Spores, Fungal; Time Factors; Toll-Like Receptor 2; Tumor Necrosis Factor-alpha

Aspergillus fumigatus is the most frequent cause of invasive mold infections worldwide. Platelets contribute to inflammation and promote thrombosis, characteristically seen in aspergillosis, and might be involved both in antifungal defense and in the histopathological process. In the experiments reported here, in vitro activation of platelets by conidia, swollen conidia, and hyphae from A. fumigatus was assessed by flow cytometry and enzyme immunoassays. THP-1 monocytes and human monocytes with and without platelets were cultured with hyphae from A. fumigatus, and the release of interleukin-8 (IL-8) was measured by enzyme immunoassays. A. fumigatus potently induced the expression of CD62-p and CD63 and the release of CD40 ligand, RANTES, and Dickkopf homolog 1 in platelets, with particularly enhancing effects of hyphae compared with conidia. The hypha-mediated activation of platelets further enhanced the release of IL-8 both in THP-1 monocytes and in human adherent monocytes. In conclusion, we have found that A. fumigatus is a potent inducer of platelet-mediated inflammation, potentially promoting protective as well as harmful responses during aspergillosis.

Topics: Antigens, CD; Aspergillosis; Aspergillus fumigatus; Blood Platelets; Cell Line; Cells, Cultured; Chemokine CCL5; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Hyphae; Intercellular Signaling Peptides and Proteins; Interleukin-8; Monocytes; P-Selectin; Platelet Activation; Platelet Membrane Glycoproteins; Spores, Fungal; Tetraspanin 30

Given the role played by chemokines in the selective homing of immune cells, we sought to characterize the profile of chemokines produced by human dendritic cells (DC) following in vitro Aspergillus fumigatus infection and their ability to recruit cells involved in the antifungal defense. At the onset of A. fumigatus infection, DC released elevated amounts of CXCL8 that promote the migration of polymorphonuclear cells (PMN). Moreover, soluble factors released from A. fumigatus-infected DC increased also the surface expression of two activation markers, CD11b and CD18, on PMN. A. fumigatus infection resulted also in CCL3, CCL4, CXCL10 and CCL20 productions that induce the migration of effector memory Th1 cells. Moreover, the late expression of CCL19 suggests that A. fumigatus-infected DC could be implicated in the migration of CCR7+ naïve T cells and mature DC in lymph nodes. Together these results suggested the involvement of human DC in the regulation of innate and adaptive immunity against A. fumigatus through the recruitment of cells active in the fungal destruction.

Topics: Aspergillosis; Aspergillus fumigatus; Chemokine CCL19; Chemokine CCL20; Chemokines; Chemokines, CC; Chemotaxis, Leukocyte; Dendritic Cells; Humans; Interleukin-8; Lymphocyte Activation; Macrophage Inflammatory Proteins; Neutrophil Infiltration; Th1 Cells

We have previously shown that moxifloxacin conferred protective anti-inflammatory effects against Candida pneumonia in immunosuppressed mice. Further in vitro studies showed anti-inflammatory effects of moxifloxacin in LPS and cytokine-stimulated monocytic and epithelial cells. In the present study, concentrating on a more challenging pathogen of immunosuppressed hosts, we studied the effect of moxifloxacin on cytokine secretion and signal transduction mechanisms in monocytic cells stimulated with Aspergillus fumigatus.. Human peripheral blood monocytes (PBMCs) and a human monocytic cell line (THP-1) were incubated with 1.5x10(6)/mL conidia of a clinical isolate of A. fumigatus. Cytokine secretion and activation of NFkappaB and the MAP-kinases ERK1/2 and p38 were measured with and without the addition of moxifloxacin (5-20 mg/L).. Stimulation of PBMCs and THP-1 cells with A. fumigatus increased IL-8, IL-1beta and TNF-alpha secretion (4.1-, 8.3- and 7-fold, and 5.4-, 3.7- and 17.8-fold, respectively). Addition of moxifloxacin (5-20 mg/L) inhibited cytokine secretion up to 45.7+/-5%, 72+/-13% and 73+/-10% in PBMCs and up to 35.6+/-0.5%, 30+/-2.4% and 19+/-4% in THP-1 cells (P<0.05). Signal transduction studies showed that incubation of THP-1 cells with A. fumigatus increased ERK1/2 and p38 phosphorylation and p65-NFkappaB protein expression by 1.6-, 1.3- and 1.8-fold, respectively. Addition of moxifloxacin inhibited ERK1/2, p38 and p65-NFkappaB by up to 69+/-14%, 58+/-3% and 75+/-15%, respectively.. Our results indicate that moxifloxacin acts as an anti-inflammatory agent in monocytic cells stimulated with A. fumigatus conidia. Whether these effects may be protective as in the Candida pneumonia model is unknown and merits in vivo studies in models of pulmonary aspergillosis.

Topics: Anti-Bacterial Agents; Anti-Inflammatory Agents, Non-Steroidal; Aspergillosis; Aspergillus fumigatus; Aza Compounds; Blotting, Western; Enzyme Activation; Enzyme-Linked Immunosorbent Assay; Fluoroquinolones; Humans; Immunosuppression Therapy; Interleukin-1; Interleukin-8; Mitogen-Activated Protein Kinases; Monocytes; Moxifloxacin; NF-kappa B; Oncogene Protein p65(gag-jun); p38 Mitogen-Activated Protein Kinases; Quinolines; Signal Transduction; Tumor Necrosis Factor-alpha

In neutrophils, superoxide anion production generally accompanies chemotaxis and functions in killing invading pathogens. The GIT2 GTPase-activating protein binds to the guanine nucleotide-exchange factor alphaPIX. Here we show that GIT2 was necessary for directional chemotaxis and for the suppression of superoxide production in G protein-coupled receptor-stimulated neutrophils. GIT2 was also necessary for the orientation of superoxide production toward chemoattractant sources. GIT2 suppressed the activity of ADP ribosylation factor 1 and was a component of the Gbetagamma subunit-mediated direction-sensing machinery 'downstream' of G protein-coupled receptor signaling. This study establishes a function for GIT2 in linking chemotaxis and superoxide production in neutrophils and shows that loss of GIT2 in vivo leads to an immunodeficient state.

Topics: Actins; ADP-Ribosylation Factor 1; Animals; Aspergillosis; Cell Cycle Proteins; Chemotactic Factors; Chemotaxis; Complement C5a; Disease Susceptibility; Enzyme Activation; GTP-Binding Protein beta Subunits; GTP-Binding Protein gamma Subunits; GTPase-Activating Proteins; Guanine Nucleotide Exchange Factors; Immunologic Deficiency Syndromes; Intercellular Signaling Peptides and Proteins; Interleukin-8; Lung; Lung Diseases, Fungal; Mice; Mice, Inbred C57BL; Mice, Knockout; Multiprotein Complexes; N-Formylmethionine Leucyl-Phenylalanine; Neutrophils; p21-Activated Kinases; Phosphatidylinositol Phosphates; Phosphoproteins; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; rac1 GTP-Binding Protein; Receptors, G-Protein-Coupled; Recombinant Fusion Proteins; Rho Guanine Nucleotide Exchange Factors; Superoxides

To study the interaction of airway epithelial cell line A549 with fragments of mycelium, spores of Aspergillus fumigatus in vitro and to determine if toll-like receptors (TLRs) are involved in the process.. A549 cells were exposed to fragments of A. fumigatus mycelium, zymosan and inactivated A. fumigatus spores. Interleukin 6 (IL-6) and IL-8 released by A549 cells to the culture supernatant were measured by ELISA. Presence of TLR2 and TLR4 on A549 cells were studied by immuno-histochemistry.. Mycelium fragments of A. fumigatus showed strong binding to epithelial cells but had limited effects on the release of IL-6 and IL-8 by A549 cells. Irradiated A. fumigatus spores were partly internalised by A549 cells and inhibited A549 cells to produce IL-6. TNF-alpha pre-incubated A549 cells produced increased IL-6 after exposure to zymosan and WIAF. Immuno-histochemistry showed a negative staining for TLR2 and TLR4.. The low levels of cytokines produced by A549 cells after the firm binding of either mycelium or spores of A. fumigatus may lead to insufficient recruitment of inflammatory cells to the infected site, which may result in the escape of detection by the immune defence system. TLR2 and TLR4 are probably not or only in part involved in the above process, although very low expression cannot be excluded.

Topics: Aspergillosis; Aspergillus fumigatus; Cell Line, Tumor; Epithelial Cells; Host-Parasite Interactions; Humans; Immunity, Innate; Interleukin-6; Interleukin-8; Mycelium; Phagocytosis; Respiratory Mucosa; Spores, Fungal; Toll-Like Receptor 2; Toll-Like Receptor 4; Zymosan

Interleukin (IL)-8 is a chemotactic cytokine that binds with high affinity to receptors on neutrophils. Previously we showed that (99m)Tc-labeled IL-8 is highly suitable for scintigraphic imaging in rabbit models of IM infection and of colitis.. (99m)Tc-labeled IL-8 was tested for its potential to image pulmonary infection in three experimental rabbit models: aspergillosis in immunocompromised rabbits, pneumococcal (Gram-positive) pneumonia, and Escherichia coli-induced (Gram-negative) pneumonia in immunocompetent rabbits (four rabbits in each group). A derivative of hydrazinonicotinamide was used as bifunctional coupling agent to label IL-8 with (99m)Tc. Biodistribution of (99m)Tc IL-8 was determined both by gamma-camera imaging and by counting dissected tissues at 6 h after injection.. (99m)Tc IL-8 enabled early (within 2 h after injection) and excellent visualization of localization and extent of pulmonary infection in each of the three experimental models of pulmonary infection. Uptake of (99m)Tc IL-8 in the infected lung and the contralateral lung was (in percentage of the injected dose per gram of tissue +/- SEM) at 6 h after injection 0.63 +/- 0.12 and 0.12 +/- 0.02 (aspergillosis), 0.89 +/- 0.04 and 0.44 +/- 0.04 (pneumococcal pneumonia), and 1.53 +/- 0.12 and 0.36 +/- 0.06 (E coli pneumonia), respectively. In the E coli model, uptake of (99m)Tc IL-8 in the focus of infection even exceeded uptake in the kidneys, the main clearing organs.. (99m)Tc IL-8 offers many advantages over the conventionally used radiopharmaceuticals to image pulmonary infection, (67)Ga citrate and radiolabeled leukocytes, ie, rapid and easy preparation, short time span between injection and imaging, low radiation burden and, most importantly, clear delineation of the infectious foci.

Topics: Animals; Aspergillosis; Escherichia coli Infections; Immunocompromised Host; Interleukin-8; Lung; Lung Diseases, Fungal; Organotechnetium Compounds; Pneumonia, Bacterial; Pneumonia, Pneumococcal; Rabbits; Radionuclide Imaging; Radiopharmaceuticals