Hodgkin and Reed-Sternberg cell-associated autoantigen CLIP-170/restin is a marker for dendritic cells and is involved in the trafficking of macropinosomes to the cytoskeleton, supporting a function-based concept of Hodgkin and Reed-Sternberg cells.
Little is known about the distribution in normal cells of CLIP-170, a linkage mediator between endocytic vesicles and microtubules, and restin, a splice variant encoded by the same gene and marker for Hodgkin and Reed-Sternberg (HRS) cells of Hodgkin disease. Although only trace amounts of CLIP-170/restin are present in peripheral blood mononuclear cell subpopulations, monocyte-derived dendritic cells (DCs) and interleukin-4 (IL-4) + CD40L-activated B cells express high levels of CLIP-170/restin. CLIP-170/restin colocalizes preferentially with membranes of intermediate macropinocytic vesicles, suggesting a new function of CLIP-170/restin in the trafficking of macropinosomes to the cytoskeleton, which is a crucial step in antigen presentation. The strong expression of CLIP-170/restin in HRS cells, DCs, and activated B cells underscores their functional similarities supporting a function-based concept of HRS cells as professional antigen-presenting cells.