Fig. 3: CXCR2 mediated cellular signaling pathways.

a Activation of β-arrestin signaling by IL-8, GRO-α, and the antibody ligands using a Tango reporter gene assay. b Inhibition of chemokine-induced β-arrestin signaling by abN48-IgG1 and abN48-2-IgG1. The induction concentration of IL-8 (left) and GRO-α (right) were at their corresponding EC₈₀ values. c Activation of Ca²⁺ influx by IL-8, GRO-α, and the abN48 antibody ligands using FLIPR measurement. d Inhibition of chemokine-induced Ca²⁺ influx by abN48-IgG1 and abN48-2-IgG1. The induction concentration of IL-8 (left) and GRO-α (right) were at their corresponding EC₉₀ values. Data are represented as mean ± standard deviation. The calculated EC₅₀ and IC₅₀ values are listed next to the fitted curves. (For Tango and Ca²⁺ assay (a–d), n = 3 independent reporter cell samples measured in a single experiment, data presented as mean (center) ± s.d. (error bars). Each assay was repeated 3 times and all gave consistent results). e Antibody-dependent CXCR2 internalization. U2OS( + ) and U2OS(−) represent U2OS cells with and without surface hCXCR2 expression, respectively; CT represents the cytotoxin AL1-PE38KDEL; abN48 represents the antibody without cytotoxin; IT-iso, IT-1, and IT-2 represent the immunotoxins (ITs) assembled with an irrelevant human IgG1 antibody, abN48-IgG1 and abN48-2-IgG1 to the cytotoxin AL1-PE38KDEL, respectively. (n = 3 independent cell samples tested in a single experiment, data presented as mean (center) ± s.d. (error bars). This assay was repeated twice and gave consistent results.).