IgG Fc receptor heterogeneity in human peripheral nerves.

The presence of Fc-receptors for IgG, FcRI (CD64), FcRII (CD32) and FcRIII (CD16) in human peripheral nerves was studied by indirect immunofluorescence staining of cryostat sections with monoclonal antibodies (mabs). The mabs 32.2 against FcRI, IV.3 and C1KM5 against FcRII, B1D6 against a 40 kD FcR with low affinity for IgG, and Leu-11b and 3G8 against FcRIII stained a few scattered cells in the endoneurium, apparently monocytes/macrophages. In addition, B1D6 and Leu11b gave a membranous staining of Schwann cells, endothelial cells and perineurial cells. Axons and fibroblasts were not stained by any of the mabs. The FcR may be important in binding immune complexes, in phagocytosis, in the release of lymphokines as well as cytotoxic and inflammatory mediators and in local immunoregulation.