Recombinant protein cell binding assay
100 nM recombinant MBP control, MBP tagged-CCP21 or MBP tagged-CCP22 was coated onto a 96 well tissue culture plate. Non-specific binding was blocked using DMEM containing 10 mg/mL bovine serum albumin, 10 mM HEPES. 20,000 HEK293 control (α4/α9-), integrin α4β1 (α4β1+), or α9β1 overexpressing (α9β1+) cells were seeded onto the coated plates in blocking buffer. The α4β1+ cells were incubated for 3 hours and the α9β1+ cells were incubated for 30 minutes at 37⁰C. and incubated at 37⁰C for 30 minutes. Plates were washed, fixed with 4% PFA and visualised using DAPI. The number of adhered cells was measured using Fiji.