| Abstract: | The L428 tumor cell line is a long-term tissue culture of Reed-Sternberg cells which was derived from the pleural effusion of a patient with Hodgkin's disease. The L428 cells express all known cell surface antigens, cytochemical staining, and cytologic features of freshly explanted Reed-Sternberg cells. In addition to the previously described HLA-DR cell surface antigens, the L428 cells are now demonstrated to express both DS and SB alloantigens. Thus, the L428 cells express all of the known subclasses of the human immune response genes that are located in the major histocompatibility complex. Furthermore, the L428 cells are capable of presenting soluble antigen to T cells in a genetically restricted fashion. T cell lines were established from normal donors previously immunized with tetanus toxoid. The T cells utilized were incapable of tetanus toxoid-induced proliferation unless antigen-presenting cells were added to the cultures. However, T cells from the two normal donors, which like the L428 cells expressed HLA-DR 5, demonstrated significant proliferative responses when cultured with tetanus toxoid and L428 cells. No proliferative response was observed when the L428 cells were used as antigen-presenting cells for a DR (4,-), DR (2,-) or DR (1,7) T cell line. The tetanus toxoid dose-response curve was similar regardless of whether autologous mononuclear leukocytes or L428 cells were used as antigen-presenting cells. The T cell proliferation induced by soluble antigen was also blocked by anti-HLA-DR antibody. Thus, functionally, Hodgkin's disease may be classified as a tumor of antigen-presenting cells. |
