Dendritic cells, implications on function from studies of the afferent lymph veiled cell

Studies of afferent lymph veiled cells (ALVC) show that the full biological function of dendritic cells in peripheral tissue is not explained by a sim ple model in which immature dendritic cells at the body surface take up ant igen, migrate via the afferent lymph ducts, mature and then effectively pre sent antigens to T-cells in the draining lymph node. Furthermore, it is evi dent from various investigations that the dendritic cells in afferent lymph , draining from the body surfaces are not a homogeneous population of cells . They comprise a mixture of cell phenotypes defined by staining with monoc lonal antibodies, and the different sub-populations have distinct biologica l functions and roles in vivo. The molecular basis for differences between the function of afferent lymph dendritic cell subsets is only now being exp lored and defined but some progress has been made in understanding the role of co-stimulatory molecules. It should be possible to exploit knowledge of the functions of these cells and aid future vaccination strategies in dome sticated animals thereby improving animal health and reducing economic loss , and, as a consequence, improving human health. By deliberately targeting functionally distinct subsets of either precursor or mature dendritic cells in vivo, it should become feasible to achieve an appropriately biased immu ne response. (C) 2000 Elsevier Science B.V. All rights reserved.