Hodgkin's cells express a novel pattern of adhesion molecules.

Adhesion molecules play an important role in the functioning of the immune system, particularly with regard to cell-cell interactions and antigen presentation. Several adhesion molecules are expressed on Hodgkin's disease-derived cell lines and these are important in their molecular interactions as antigen presenting cells (APC). There are no data regarding the expression of many of these adhesion molecules on Reed-Sternberg cells and its mononuclear variant (Hodgkin's cells (HC)) present in pathological material. To obtain this information we undertook an immunohistological study on material from 18 cases of Hodgkin's disease using a panel of MoAbs to examine the expression of adhesion molecules on HC. The HC were shown to express the integrin beta 1 subfamily molecules, LFA-1 (CD11a) and p150,95 (CD11c) in high density but lacked CR3 (CD11b). All of the immunoglobulin gene superfamily adhesion molecules studied were present to some degree on HC, with ICAM-2, in particular, showing moderate to strong expression in most cases. The Hermes antigen CD44 was present in high density but leukosialin (CD43), another molecule present on diverse leucocyte types, was, in general, not detected on HC. These new data showing that ICAM-1, ICAM-2 and LFA-3 are, like LFA-1, expressed on HC emphasize the ability of HC to act as APC. The known adhesion molecule phenotype of the recently defined haematopoietic lineage of human dendritic cells (DC) is broadly similar to that of HC, perhaps supporting the hypothesis that some HC represent a malignancy of an APC (DC) lineage.