recombinant fc gamma receptors  (R&D Systems)

Journal: Frontiers in Immunology

Article Title: Extracellular caspase-1: a critical inducer and a therapeutic target of lung injury in gut ischemia-reperfusion

doi: 10.3389/fimmu.2026.1811868

Figure Lengend Snippet: eCasp-1 binds to TLR4 to drive inflammation, which is effectively suppressed by the novel peptide C16. (A, B) Computational modeling predicted a strong interaction between eCasp-1 (red) and TLR4 (blue). (C) SPR analysis on the binding of eCasp-1 to TLR4 in vitro . (D, E) WT and TLR4 -/- peritoneal macrophages were treated with PBS or eCasp-1 (0.1 µg/ml) for 4 h. (D) IL-6 and (E) TNFα levels in the supernatants were measured by ELISA. (F, G) WT and TLR4 -/- mice received i.p. injections of PBS or eCasp-1 (5 µg/g BW), and plasma was collected 24 h later to measure (F) IL-6 and (G) TNFα. (H) In-silico analysis identified a putative binding site for mouse eCasp-1 (red) on the extracellular domain of TLR4 (blue). (I) C16 (silver), a 16-amino-acid peptide mimic, was designed based on the predicted binding interface and exhibited strong binding to eCasp-1 (red). (J) Computational modeling predicted a potential interaction between the eCasp-1-C16 complex and TLR4. (K) SPR analysis of eCasp-1 binding to TLR4 in the presence or absence of C16. (L) WT peritoneal macrophages were treated with eCasp-1 (0.1 µg/mL) with increasing concentrations of C16 (0.1, 1, 10 µg/mL) for 4 h, and TNFα levels in the supernatants were measured by ELISA. Experiments were repeated 2–3 times and all the data obtained were used for analysis. Data were expressed as mean ± SEM (n = 5–9 samples/group) and compared by one-way analysis of variance and Student-Newman-Keuls method ( * p < 0.05 vs. WT PBS; # p < 0.05 vs. WT with eCasp-1, (+)eCasp-1 (-)C16).

Article Snippet: Recombinant mouse TLR4 (rmTLR4; ≥90% purity) was purchased from R&D Systems (Cat. No. 9149-TR-050, Minneapolis, MN), supplied in carrier-free form, and reconstituted in sterile PBS according to the manufacturer’s instructions.

Techniques: Binding Assay, In Vitro, Enzyme-linked Immunosorbent Assay, Clinical Proteomics, In Silico

Journal: Frontiers in Immunology

Article Title: Extracellular caspase-1: a critical inducer and a therapeutic target of lung injury in gut ischemia-reperfusion

doi: 10.3389/fimmu.2026.1811868

Figure Lengend Snippet: Summary of findings. In gut I/R injury, inflammasomes activation promotes the cleavage of caspase-1 and the extracellular release of its p20 subunit through GSDMD-dependent membrane processes. This release may occur in association with GSDMD pore formation as well as membrane disruption during lytic cell death (pyroptosis). Once released, extracellular caspase-1 (eCasp-1) acts as a potent DAMP by binding to TLR4, thereby amplifying release of inflammatory cytokines, aggravating lung injury. Therapeutic intervention with the inhibitory peptide C16, which specifically blocks the eCasp-1-TLR4 interaction, effectively attenuates systemic inflammation and improves survival outcomes. I/R, Ischemia-reperfusion; GSDMD, Gasdermin-D; eCasp-1, Extracellular caspase-1; DAMP, Damage-associated molecular pattern; TLR4, Toll-like receptor 4.

Article Snippet: Recombinant mouse TLR4 (rmTLR4; ≥90% purity) was purchased from R&D Systems (Cat. No. 9149-TR-050, Minneapolis, MN), supplied in carrier-free form, and reconstituted in sterile PBS according to the manufacturer’s instructions.

Techniques: Activation Assay, Membrane, Disruption, Binding Assay