PV-1 and vimentin can be coimmunoprecipitated from HUVECs. (A) Coprecipitations from nonactivated HUVECs. (B) Coprecipitations from TNF-α–activated HUVECs. HUVECs were lysed and the lysate incubated with magnetic beads coupled to primary antibodies against vimentin and an isotype-matched negative control antibody (AK1). Detection was performed with antibodies against the suspected binding partner indicated in the figure. Arrows point to nonspecific bands deriving from the heavy chains of the immunoglobulins. PV-1 bands of approximately 62 kDa can be seen in lane 1 (A-B), where precipitation was performed with anti-vimentin antibody and detection with anti–PV-1 antibody. In addition, in panel B lane 1, a weaker PV-1 band of approximately 55 kDa can be seen.