In vivo diffusion of CXCL4 and CXCL4L1. (A) Injection of rCXCL4, rCXCL4L1, or GST labeled with IRDye800CW in RAG-γ/c mice (n = 6). Biodistribution was monitored with IR signal at 1, 24, and 48 hours after injection. GST was still detected at 72 hours, whereas CXCL4 and CXCL4L1 were completely cleared from the mice. (B) In vivo diffusion of human CXCL4 and CXCL4L1 expressed in mice using electrotransfer in the tibialis anterior muscle (n = 6). Plasma levels were determined using a human CXCL4-ELISA (left panel) specific for human chemokines. No signal was detected in controls (mouse tissue). Expression of human CXCL4 and CXCL4L1 in the tibialis anterior muscle was also detected by Western blot using Mab-L4 (right panel). The graphs represent the densitometric analysis. No signal was observed for control mice electrotransfered with the empty vector.