BINDING AND INTERNALIZATION OF HUMAN-IGG BY LIVING CULTURED ENDOTHELIAL-CELLS

Interactions between circulating IgG and endothelial cells (EC) in hum ans have been described only in conditions associated with pathologic immunoglobulins and/or activated or damaged EC. In this study we provi de evidence that normal human IgG includes one/some antibody species t hat bind to and are internalized by living EC in culture. This novel f unction of EC and natural autoantibodies is of potential importance fo r the understanding of physiologic interactions between vessels and th e immune system and for the clarification of pathogenesis of vasculiti s and mechanisms of action of pooled IgG used in the therapy of such c onditions.