Figure 2.

LCL secrete exosomes containing FasL and MHC class II. (A) Cell lysates and spontaneously secreted exosomes were collected from four LCL (lines E, P, 2, and 4) and probed for the presence of FasL and HLA-DR by immunoblot. (B) Exosomes from a representative LCL were floated onto a discontinuous density gradient of iodixanol solution and spun for 1 h at 100,000 × g. Individual layers were removed and diluted with PBS, followed by an overnight centrifugation at 100,000 × g. The resulting pellets were lysed with SDS buffer and probed for FasL by immunoblot.