Figure 1. Importance of intracellular signaling cascades in the pMV-absorption.

(A) Wild type (WT), CD28^−/−, and LFA-1^−/− 2C T cells, pre- treated with the respective mAbs, were cultured with or without the peptide-loaded L^dB7-1ICAM-1 pMVs, as indicated, followed by mAb staining for B7-1 and flow cytometric analysis. Mean fluorescence intensities (MFIs) of B7-1 staining relative to that of WT 2C T cells, pre-treated with control mAb and cultured with the QL9-loaded pMVs, were plotted. Note that P1A peptide forms complex with L^d but L^d/P1A complex is not recognized by 2C TCR [8]. (B) WT 2C T cells, pre-treated with the respective mAbs, were cultured with the peptide-loaded pMVs for different periods of time, as indicated, and stained for B7-1. (C) WT 2C T cells were treated with PP2 (PP), Wortmannin (WM), Pervanadate (PV), Cytochalasin D (CT), BAPTA/AM (BA), Forskolin (FS), Cyclosporin A (CC) and Nocodazole (NZ), respectively, as indicated, before culture with the QL9-loaded pMVs. MFIs of the B7-1 staining relative to that of 2C T cells treated with DMSO alone were plotted.