Dendritic Cell Identification in Head and Neck Lymphoid Tissue: Newly Recognized Cells Control T-Lymphocyte Functions

Abstract

\s=b\The physiologic measurements of a subpopulation of mononuclear cells derived from head and neck lymphoid tissues are similar to those of dendritic cells are described. Dendritic cells are a subpopulation of bone marrow-derived leukocytes that were originally identified in rodents and now described in man as having central control of T-lymphocyte functions. We describe a technique for the enrichment of dendritic cells obtained from tonsils utilizing a bovine serum albumin (BSA) gradient and note that they have the light and electron microscopic appearance of dendritic cells. The measured oxidative mitogenic response and interferon-\g=g\production in complete leukocyte cultures was compared with BSA gradient-separated preparations. The denser cells, comprised mostly of normal appearing lymphocytes, would not undergo a mitogenic response nor produce normal amounts of interferon when stimulated unless the dendritic cell-rich, lessdense fraction, was added back. The dendritic cells derived from tonsils seem to behave as a potent accessory cell for these T-lymphocyte-associated functions. (Arch Otolaryngol 1984;110:701-706) During the last several years, Steinman and his colleagues'·6 at Rockefeller University, New York, have described a novel cell in the peripheral lymphoid organs of mice.These cells are called dendritic cells because of their irregularly shaped dendritic processes, but are bone mar¬ row-derived leukocytes and are not part of the nervous system. The gen¬ eral group of dendritic cells are leuko¬ cytes referred to in other works by a variety of names, including dendritic cells and interdigitating cells in lym¬ phoid tissues and veiled cells in lymph.' These are similar to but can be differentiated from epidermal Langerhans' cells and follicular ger¬ minal center dendritic cells.The recent major effort has been to distinguish dendritic cells from cells within the macrophage group.8 Den¬ dritic cells lack active endocytotic capacities, which is a cardinal feature of other mononucler cells.