Growing evidence supports the concept that immune reactions occur in the cochlea, where they can function either in protection or as a source of inflammation. Since immunity is generally initiated by antigen presentation of foreign substances to T cells, antigen-presenting cells expressing major histocompatibility complex (MHC) class II molecules are required. Under resting conditions, cochlear...

Prostaglandins, pleiotropic immune modulators that induce protein kinase A (PKA), inhibit gamma interferon induction of class II major histocompatibility complex (MHC) genes. We show that phosphorylation of CIITA by PKA accounts for this inhibition. Treatment with prostaglandin E or 8-bromo-cyclic AMP or transfection with PKA inhibits the activity of CIITA in both mouse and human monocytic cell...

Murine epidermal Langerhans cells were analyzed with fluorescence microscopy and multicolor flow cytometry for the surface expression of major histocompatibility complex (MHC) class I and class II antigens. Langerhans cells of H-2k haplotype were identified in situ or in epidermal-cell suspensions by their surface expression of the MHC class II determinants I-Ak and I-Ek. More than 90% of class...

Dendritic cells have the capacity to trigger T cell responses in lymphoid organs against antigens captured in the periphery. T cell stimulation depends on the ability of MHC class II molecules to present peptides at the cell surface that are acquired in MHC class II compartments. The high capacity of dendritic cells to stimulate T lymphocytes is related to their ability to regulate the distribu...

One mechanism by which viral tropism may be controlled is by the expression of a specific virus receptor on the cell surface. This paper reports the identification of a putative cellular receptor for visna virus, the prototype virus of the family Lentiviridae. Using a virus overlay protein blot assay we identified a group of polypeptides of apparent Mr 30K to 33K which interacts with visna viru...

MHC molecules associated with autoimmunity possess known structural features that limit the repertoire of peptides that they can present. Such limitation gives a selective advantage to TCRs that rely on interaction with the MHC itself, rather than with the peptide residues. At the same time, negative selection is impaired because of the lack of negatively selecting peptide ligands. The combinat...