CD43 from fresh, resting human peripheral-blood T cells is decorated with CLA and binds E-selectin. (A) Purification of CLA⁺ T cells from peripheral blood was assessed by staining with anti-CLA mAb HECA-452 (solid line) versus unstained control cells (dotted line). Lysates of CLA⁺ peripheral-blood T cells were immunoprecipitated with anti-CD43 mAb 1G10 and subjected to nonreducing SDS-PAGE. (B) Western blots stained with anti-CD43 mAb DF-T1-biotin show 2 bands of 125 kDa and 115 kDa, similar to those seen with cultured T cells. High-range and full-range molecular weight markers were run in the left and right flanking lanes, respectively. (C) Blot-rolling analysis showed that CHO-E cells (▪), but not CHO-P () or mock-transfected CHO () cells, tether and roll on the 125-kDa isoform, but not the 115-kDa isoform, of CD43 from peripheral-blood T cells. Separation of CD43 from PSGL-1 in this IP was confirmed by the lack of CHO-E or CHO-P binding unstimulated or CLA⁺ stain in the 140-kDa region of these Western blots (not shown). CHO-E binding to 125-kDa CD43 was abrogated in the presence of 5 mM EDTA (not shown). Results shown are mean and SEM of 3 or more observations.