IgD-receptor-positive human T lymphocytes: I. Modulation of receptor expression by oligomeric IgD and lymphokines

Studies with human myeloma-derived IgD have demonstrated the existence of IgD-R on peripheral blood T cells. These receptors, which are detected by resetting with IgD-coated ox E (IgD-rosette-forming cells), are competitively inhibited by IgD, but not by IgM or IgG. Similar results were obtained with human T cell clones and T hybridomas derived from such clones either by resetting assays or by staining with biotinylated-IgD. In agreement with studies of murine IgD-R⁺ cells, human IgD-R can be up-regulated by exposure of peripheral blood T cells, T cell clones, and hybridomas derived from such clones, to oligomeric IgD, but not monomeric IgD. Human IgD-R can also be induced by IL-2, IL-4, and IFN-γ. In contrast with studies of murine IgD-R, which are expressed primarily by CD4⁺ cells, phenotyping studies show that both the CD4⁺ and CD8⁺ human T cell subsets are capable of expressing IgD-R.