Journal: Frontiers in Immunology

Article Title: Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices

doi: 10.3389/fimmu.2021.777932

Figure Lengend Snippet: Microfluidic devices for measuring neutrophil chemotaxis, phagocytosis, and swarming behaviors. (A) Microscopic image of a segment of the chemotaxis microfluidic device (x10 Brightfield, Nikon TiE) showing neutrophil chemotaxis towards C5a and C3a during increasing mechanical restriction. Each chemoattractant chamber is connected to the cell loading channel through 3 tapered channels. (B) Microscopic image of a segment of the phagocytosis microfluidic device (x10 Brightfield/Fluorescent, Nikon TiE) showing neutrophils (blue nuclei) from the outer chamber migrating towards the central reservoir through a migration channel to phagocytose S. aureus particles (green) in plasma at T 20 minutes. (C) Microscopic images obtained at three different time points (T 0 , T 10 , and T 30 minutes) showing the formation of a neutrophil swarm (blue nuclei) over a cluster of Texas red-labeled zymosan A S. cerevisiae bioparticles (Red).

Article Snippet: The chemoattractant chambers were filled either with fMLP (N-formyl-methionyl-leucyl-phenylalanine, 100 nM, Millipore Sigma), recombinant human C5a protein (ab61918, 0.1 - 10 μM, Abcam), or C3a (3677-C3-025, 0.1 - 10 μM, R&D Systems) diluted in HBSS with 0.5% BSA during the initial priming step.

Techniques: Chemotaxis Assay, Migration, Clinical Proteomics, Labeling

Journal: Frontiers in Immunology

Article Title: Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices

doi: 10.3389/fimmu.2021.777932

Figure Lengend Snippet: Chemotaxis of isolated neutrophils towards C5a and C3a and the effect of AVA on chemotaxis. (A) The percentage of neutrophils migrating directionally towards increasing concentrations of C5a and C3a compared to media alone (HBSS with 0.5%BSA, N=3, ****p < 0.0001; One-way ANOVA with Dunnett’s test) (B) C3a inhibits neutrophil chemotaxis towards C5a, C5a effect is dependent on concentration, and there is no interaction effect between C3 and C5a. (N=3 donors, p < 0.005, Repeated measures, two way ANOVA, with Sidak’s correction for multiple comparisons). (C) Percentage of neutrophils migrating directionally towards C5a (100 nM) after treatment of neutrophils with C5aR1 antagonist AVA (N=3, 4 or 5, each dot on the plot represents one experiment, ****p < 0.01 for comparisons to C5a control; ns represents not statistical significant. One way ANOVA with Dunnett’s multiple comparison test with single pooled variance).

Article Snippet: The chemoattractant chambers were filled either with fMLP (N-formyl-methionyl-leucyl-phenylalanine, 100 nM, Millipore Sigma), recombinant human C5a protein (ab61918, 0.1 - 10 μM, Abcam), or C3a (3677-C3-025, 0.1 - 10 μM, R&D Systems) diluted in HBSS with 0.5% BSA during the initial priming step.

Techniques: Chemotaxis Assay, Isolation, Concentration Assay, Control, Comparison

Journal: Frontiers in Immunology

Article Title: Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices

doi: 10.3389/fimmu.2021.777932

Figure Lengend Snippet: Atypical membrane elasticity of neutrophils and migration patterns when exposed to high C5a dose. (A) Percentage of neutrophil migration patterns during chemotaxis towards C5a, C3a, and fMLP. (N=3). (B) Microscopic images of elongated neutrophils when exposed to C5a 1µM inside the end chambers. Scale = 100 µm. (C) Percentages of unique reversed migration phenotype of neutrophils observed when exposed to high C5a concentration. (N=3, *p < 0.05; ns represents not statistical significant. One-way ANOVA with Dunnett’s test).

Article Snippet: The chemoattractant chambers were filled either with fMLP (N-formyl-methionyl-leucyl-phenylalanine, 100 nM, Millipore Sigma), recombinant human C5a protein (ab61918, 0.1 - 10 μM, Abcam), or C3a (3677-C3-025, 0.1 - 10 μM, R&D Systems) diluted in HBSS with 0.5% BSA during the initial priming step.

Techniques: Membrane, Migration, Chemotaxis Assay, Concentration Assay

Journal: Frontiers in Immunology

Article Title: Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices

doi: 10.3389/fimmu.2021.777932

Figure Lengend Snippet: Effect of C5 complement inhibitors on neutrophil chemotaxis towards endogenous complement activation with CVF. (A) Effect of AVA (250 nM) on endogenous complement activation by increasing CVF doses (N=3 donors, *p < 0.05, **p < 0.01; paired two-tailed t -test). (B) Effect of C5 inhibition with ECU (3 µM) and RA101295 (3 µM) on endogenous complement activation by CVF (N=3, **p < 0.01; ns represents not statistical significant. One-way ANOVA with Dunnett’s test).

Article Snippet: The chemoattractant chambers were filled either with fMLP (N-formyl-methionyl-leucyl-phenylalanine, 100 nM, Millipore Sigma), recombinant human C5a protein (ab61918, 0.1 - 10 μM, Abcam), or C3a (3677-C3-025, 0.1 - 10 μM, R&D Systems) diluted in HBSS with 0.5% BSA during the initial priming step.

Techniques: Chemotaxis Assay, Activation Assay, Two Tailed Test, Inhibition

Journal: Frontiers in Immunology

Article Title: Human Neutrophils Respond to Complement Activation and Inhibition in Microfluidic Devices

doi: 10.3389/fimmu.2021.777932

Figure Lengend Snippet: Schematic representation of complement activation pathways, terminal inhibition strategies, and their effects on neutrophil functional behaviors. The classical, lectin, and alternative pathways converge on the cleavage of the central components C3 into C3a and C3b peptides. C3a acts as an anti-inflammatory mediator towards neutrophils, while C3b enhances phagocytosis through opsonization and forms C5 convertases, which cleaves C5 into C5a and C5b. C5a is a potent pro-inflammatory mediator and chemoattractant, while C5b forms the membrane attack complex (MAC), leading to cell and bacteria lysis. ECU and RA101295 are C5-inhibitors, which block the production of C5a and C5b peptides, while AVA blocks C5a mediated chemotaxis and pro-inflammatory effects.

Article Snippet: The chemoattractant chambers were filled either with fMLP (N-formyl-methionyl-leucyl-phenylalanine, 100 nM, Millipore Sigma), recombinant human C5a protein (ab61918, 0.1 - 10 μM, Abcam), or C3a (3677-C3-025, 0.1 - 10 μM, R&D Systems) diluted in HBSS with 0.5% BSA during the initial priming step.

Techniques: Activation Assay, Inhibition, Functional Assay, Membrane, Bacteria, Lysis, Blocking Assay, Chemotaxis Assay

Journal: Cellular & molecular medicine: open access

Article Title: Potential Mechanisms Underlying TGF-β-mediated Complement Activation in Lung Fibrosis

doi:

Figure Lengend Snippet: RNA interference suppresses local complement activation. BALF collected from Figure 1 were analyzed for C3a (A) and C5a (B) levels in the lung by ELISA. Values: Means ± SEM. (n=5-7 per group). One-way ANOVA, Newman-Keuls (A, B). Compared to bleomycin: ***: p<0.001; **: p<0.01; *: p<0.05. Results are representative of three independent experiments.

Article Snippet: These studies used recombinant human C3a and C5a (100 nM; Complement Technology, Inc., Tyler, TX), platelet-derived TGF-β1 (2 ng/ml; Roche Diagnostics, Germany).

Techniques: Activation Assay, Enzyme-linked Immunosorbent Assay

Journal: Cellular & molecular medicine: open access

Article Title: Potential Mechanisms Underlying TGF-β-mediated Complement Activation in Lung Fibrosis

doi:

Figure Lengend Snippet: miRNA regulation in response to TGF-β, C3a and C5a for 24 h in normal primary human SAECs.

Article Snippet: These studies used recombinant human C3a and C5a (100 nM; Complement Technology, Inc., Tyler, TX), platelet-derived TGF-β1 (2 ng/ml; Roche Diagnostics, Germany).

Techniques: