Human rheumatoid synovial and normal blood dendritic cells as antigen presenting cell--comparison with autologous monocytes.

Rheumatoid dendritic cells (DC) from synovial membrane and synovial fluid and normal dendritic cells from peripheral blood were compared with autologous monocytes concerning accessory activities for T cell antigen responses. Purified protein derivative of tuberculin (PPD), herpes simplex virus type 1 antigen (HSV) and Chlamydia trachomatis antigen were used as antigens. The dendritic cells were shown to be efficient antigen presenting cells for the various antigens and were much more potent than monocytes. The DC were strongly positive for major histocompatibility complex (MHC) class II antigens. The T cell responses both to bacterial and viral antigens induced by DC could all be inhibited by monoclonal antibodies against HLA-DQ and HLA-DR antigens. Dendritic cells may thus play an important role as accessory cells in presenting antigens for T cells in the context fo class II MHC molecules in the rheumatoid inflammation.