These Proceedings contain the contributions of the participants of the Second International Symposium on Dendritic Cells that was held from the 1st to 25th of June 1992 in Amsterdam, the Netherlands. The First International Symposium on Dendritic Cells was organized as a Satellite symposium at the occasion of the 30th anniversary of the Japanese Reticuloendothelial Society by Dr. Y. Imai in Yamagata (Japan), in 1990. It was entitled "Dendritic Cells in Lymphoid Tissues," and focused primarily on the Interdigitating Cells (IDC), Epidermal Langerhans cells (LC) and Follicular Dendritic Cells (FDC) , from the point of view of human pathology. However, the concept of Dendritic Cell System, comprising the bone marrow derived IDC and LC but not the FDC, was based on animal experiments and mainly on in vitro experiments on isolated cells. In a report from the Reticuloendothelial Society Committee on Nomenclature in 1982, Tew, Thorbecke and Steinman had already characterized these different types of DC, but the gap between in vivo and in vitro function remained. In Amsterdam, the Symposium focused on the Role of Dendritic Cells in Fundamental and Clinical Immunology. First, recent developments in molecular biology of antigen presentation and cell biological aspects of signal transduction were discussed, in relation to the potential of DC to stimulate lymphocytes and to trigger their in vitro differentiation.

General Introduction: Dendritic cells: Antigen presentation, accessory function and clinical relevance.- Endocytic activity of dendritic cells is similar to other antigen presenting cells.- Immunocytochemical characterization of dendritic cells.- Requirements of exogenous protein antigens for presentation to CD4+ T lymphocytes by MHC Class II-positive APC.- Modulation of MHC Class II determinants on rat Langerhans cells during short term culture.- A dendritic cell specific determinant present in endosomes is involved in the presentation of protein antigens.- Dendritic cells are potent antigen-presenting cells for microbial superantigen.- Divergent T-cell cytokine profiles induced by dendritic cells from different tissues.- Adhesion molecules: Co-stimulators and Co-mitogens in dendritic cell - T cell interaction.- Dendritic cell dependent expression of IgA by clones in T/B microcultures.- Adhesion molecules in tonsil DC-T cell interactions.- Dendritic cells have reduced cell surface membrane glycoproteins including CD43 determinants.- The effect of human dendritic cells on the lectin-induced responsiveness of CD4+ T cells to IL-2 and IL-4.- Analysis of cytokine and cytokine receptor production by human dendritic cells.- Costimulating factors and signals relevant for antigen presenting cell function.- Distinct T cell stimulation mechanism and phenotype of human blood dendritic cells.- The role of dendritic cells in the regulation of T cell cytokine synthesis.- The role of dendritic cells as co-stimulators in tolerance induction.- The influence of dendritic cells on T-cell cytokine production.- Phenotypical and functional characterization of dendritic cells in the human peritoneal cavity.- Dendritic cells isolated from rat and human non-lymphoid tissue are very potent accessory cells.- Antigen presenting capacity of peritoneal macrophages and dendritic cells.- T-cell repertoire development in MHC class II deficient humans.- Rat thymic dendritic cells.- Rat thymic dendriticCells: flow cytometry analysis.- Ultrastructure of interdigitating cells in the rat thymus during Cyclosporin A treatment.- T cell tolerance and antigen presenting cell function in the thymus.- Tolerizing mice to human leukocytes: A step toward the production of monoclonal antibodies specific for human dendritic cells.- Morphological and functional differences between HLA-Dr+ peripheral blood dendritic cells and HLA Dr+ IFN-alpha producing cells.- Three monoclonal antibodies to antigen presenting cells in the rat with differential influence on cellular interactions.- The MHC expression of dendritic cells from mouse spleen isolated by centrifugal elutriation is unregulated during short term culture.- II-6 and its high affinity receptor during differentiation of monocytes into Langerhans cells.- Phagocytosis of antigens by Langerhans cells.- Dissection of human Langerhans cell allostimulatory function. Modulation by interferon-?.- Human in vitro T cell sensitization using hapten-modified epidermal Langerhans cells.- Monocyte-derived Langerhans cells from different species - morphological and functional characterization.- A serial section study of mice Langerhans cell granules after DNFB painting.- Skin dendritic cell-lymphocyte interactions in autologous system.- Induction of the low affinity receptor for IgE (Fc?RII/CD23) on human blood dendritic cells by interleukin-4.- Fc? RI mediates IGE-binding to human epidermal Langerhans cells.- Murine epidermal Langerhans cells as a model to study tissue dendritic cells.- Differentiation of dendritic cells in cultures of rat and mouse bone marrow cells.- TNF and GM-CSF dependent growth of an early progenitor of dendritic Langerhans cells in human bone marrow.- Human bone marrow contains potent stimulatory cells for the allogeneic MLR with the phenotype of dendritic cells.- Recombinant GM-CSF induces in vitro differentiation of dendritic cells from mouse bone marrow.- Signals required for differentiating dendritic cells...