Figure 5
Human TIM-3 and human CEACAM1 binding studies by ELISA. (a) hTIM-3 Fc fusion protein but not hIgG-Fc fusion protein (0–4 μM) binds to tagless hCEACAM1 IgV domain with EC50 of 1.50 μM. (b) Blockade of the interaction between tagless hCEACAM1 and hTIM-3 Fc fusion protein with 10 μM of hTIM-3 C-C′ loop-derived peptide (amino acids 58–77) but not by 10 μM of scrambled peptide. (c) Binding of tagless hTIM-3 IgV domain with glutathione-S-transferase (GST) tagged hCEACAM1 IgV-domain protein (0–15 μM) with EC50 of 3.13 μM, but not with GST protein (0–15 μM). (d) Significant blockade of interaction between tagless hTIM-3 IgV domain and glutathione-S-transferase (GST) tagged hCEACAM1 IgV-domain fusion protein by a mouse anti-human CEACAM1 IgV-domain specific monoclonal 5F4 antibody (0–1 μM), but not by a isotype control MOPC antibody. (a–d) ELISA binding assays were performed in triplicate and the average values are shown with standard deviations. n.s., not significant. p values ≤ *0.05, **0.01, and ***0.001.
