Western blot analysis
Primary Th2 cells were harvested in lysis buffer and protein electrophoresed on SDS-Page gel. Gels were wet transferred onto nitrocellulose membrane, blocked with milk (Carnation skim milk powder, 5%) and incubated with antibody against CRTh2. Membranes were washed in TBS-T and incubated with horseradish peroxidase secondary antibody. Bands were detected using Clarity Western ECL substrate (Bio-Rad, CA, USA) and images were acquired using a ChemiDoc MP Imaging System. GAPDH was detected after stripping the membranes and re-probing with antibody against GAPDH. Densitometry of CRTh2 was normalized to GAPDH using ImageJ.