Human CD207 peptide

Dendritic cells (DCs) are strategically positioned to take up antigens and initiate adaptive immunity. One DC subset expresses CD8 alpha alpha in mice and is specialized to capture dying cells and process antigens for MHC class I "cross-presentation." Because CD8(+) DCs also express DEC205/CD205, which is localized to splenic T cell regions, it is thought that CD8(+) DCs also are restricted to T zones. Here, we used a new antibody to Langerin/CD207, which colabels isolated CD8(+) CD205(+) DCs, to immunolabel spleen sections. The mAb labeled discrete cells with high levels of CD11c and CD8. Surprisingly most CD207(+) profiles were in marginal zones surrounding splenic white pulp nodules, and only smaller numbers were in T cell areas, where CD205 colabeling was noted. Despite a marginal zone location, CD207(+) DCs lacked identifying molecules for 3 different types of macrophages, localized in proximity and, in contrast to macrophages, marginal zone DCs were poor scavengers of soluble and particulate substrates. After stimulation with microbial agonists, Langerin expression disappeared from the marginal zone at 6-12 h, but was greatly expanded in the T cell areas, and by 24-48 h, Langerin expression disappeared. Therefore, anti-Langerin antibodies localize a majority of CD8(+) DCs to non-T cell regions of mouse spleen, where they are distinct from adjacent macrophages.

The ontogeny and disease responses of Langerhans-like cells within lymphoid tissues of Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss, were investigated. These cells were studied in situ with the use of two markers: the ultrastructural presence of Birbeck-like granules and immunohistochemistry with an antibody against human langerin/CD207 that cross-reacts with salmonid tissues. The appearance of Birbeck-like granules was observed in rainbow trout at 2 weeks post-hatch (PH) in the thymus and anterior kidney prior to the development of the spleen. Spleen first appeared at 3 weeks PH in both Atlantic salmon and rainbow trout, and Birbeck-like granules were observed within cells of the newly developed spleens. The cross-reactivity of langerin as seen by immunohistochemistry was not clearly observed in kidney and spleen until 9 weeks PH, when a strong cytoplasmic reaction was observed. To study langerin-positive cells in spleen and kidney during disease, microsporidial gill disease (MGD) in rainbow trout was used as a known disease model inducing a strong cell-mediated adaptive immune response. Langerin-positive cells in healthy fish were seen predominantly in the spleen, and only low numbers were present in the anterior kidney. During MGD, langerin-positive cell numbers were elevated in the anterior kidney and were significantly higher during 5, 6, and 10 weeks post-exposure (PE) compared with healthy control tissue. During MGD, the distribution of langerin-positive cells in the spleen and anterior kidney shifted from having significantly higher numbers of cells in the spleen than in the kidney in controls and at 1 and 4 weeks PE to having a similar distribution of the cells in the two organs at 2, 3, 5, and 6 weeks PE. By 10 weeks PE, significantly higher numbers of langerin-positive cells occurred in the anterior kidney compared with the spleen.