CLA⁺ CD43 displays E-selectin ligand activity in a blot-rolling assay. (A) Lysates of cultured CLA⁺ T cells were immunoprecipitated with anti-CD43 mAb 1G10 and the products were subjected to nonreducing SDS-PAGE. Representative Western blots stained for CD43 (mAb DF-T1) and CLA (mAb HECA-452). High-range (left) and full-range (right) molecular weight markers are included in the flanking lanes of each blot. Unmanipulated lysate (Original) shows 125- and 115-kDa CD43⁺ bands as seen in Figure 3. IP of CD43 results in recovery of both 125-kDa and 115-kDa CD43 (Pellet, CD43 stain). Staining of an identical blot for CLA (Pellet, HECA-452 stain) shows the 125-kDa isomer of CD43 bears CLA whereas the 115-kDa form does not. Blots from panel A were assayed for functional E-selectin ligand activity by blot-rolling analysis (B). E-selectin ligand activity was observed on immunoprecipitated 125-kDa CD43, but not immunoprecipitated 115-kDa CD43 (▪), was calcium dependent (5 mM EDTA, □). Neither form supported P-selectin () or control cell binding () in shear flow. Results shown are mean and SEM of 3 to 6 separate determinations on each band collected in 2 independent experiments.