Langerhans cells: Target cells in immune complex reactions

Abstract

Skin of normal, cobra venom extract-treated, and C 4-deficient guinea pigs was injected with ferritin-antiferritin or with peroxidase-antiperoxidase immune complexes. Skin and draining lymph nodes were studied to compare the phagocytosis of these immune complexes by Langerhans cells (LC) and by macrophages. When complement was present, immune complexes were damaging to LC, and uptake of the immune complexes, although present, was limited. When components of complement were absent or diminished, increased numbers of LC in lymph nodes were seen, but damage to LC was absent or decreased. However no detectable change in the amount of phagocytosis by LC was noted. Since some LC can carry antigen from skin to lymph nodes and may be involved in the presentation of antigen to lymphoid cells in some cell-mediated immune responses, impairment or abolition of LC function by immune complexes could represent a mechanism through which the local presence of antibodies might interfere with the induction and elicitation of cellular immunity by antigen. Moreover, damage to LC and subsequent release of intracellular (lysosomal?) substances may constitute a general mechanism of response in the skin to injury and may be an integral part of inflammatory and allergic skin reactions.