Association between CD26 and CD45RA in CBTCs. PBTCs (P) and CBTCs (C) were incubated with anti-CD26 mAb (1F7) and then cross-linked with secondary antibodies followed by cross-linking with the cleavable cross-linker DTSSP. CD26 and its cross-linked complex were immunoprecipitated as described in “Materials and methods.” Immunoprecipitated materials were analyzed by SDS-PAGE under reducing conditions and then immunoblotted with anti-CD26 and anti-CD45RA mAb.