Effect of TSP cell-binding domain inhibitory antibodies and peptides on SS-RBC adhesion to TSP. (A) Washed SS-RBCs were incubated with control buffer (None), 7N3 peptide FIRVVMYEGKK (7N3, 200 μmol/L, N = 2), 4N1K peptide KRFYVVMWKK (4N1K, 200 μmol/L, N = 2), or both 4N1K and 7N3 peptides (4N+7N, 200 μmol/L, N = 2) for 60 minutes at 37°C before the flow adhesion assay. Treated RBCs were perfused through flow chambers coated with immobilized TSP as described in the legend to Fig 1. Immobilized TSP was incubated with 5 μg/mL purified anti-TSP MoAb 6.7 (C6.7) or isotype-specific control MoAb MBC 35.5 (Control) for 30 minutes at 37°C before performing the flow adhesion assay as described above (N = 3). Similar results were found incubating SS-RBCs with MoAbs in ascites fluid (C6.7 and MBC 35.5, diluted 1:1,000) before the flow adhesion assay (N = 9). (B) G361 cells were incubated with control buffer (None, N = 4), scramble control peptide (Scramble, 200 μmol/L, N = 8) 7N3 peptide (7N3, 200 μmol/L, N = 4), 4N1K peptide (4N1K, 200 μmol/L, N = 4), or immobilized TSP was incubated with anti-TSP MoAb 6.7 (C6.7, N = 4) for 30 to 90 minutes at 37°C before the flow adhesion assay. G361 cells were then perfused through the flow chambers coated with immobilized TSP as described in Fig 1.