%0 Journal Article
%T Expression and functional effects of Eph receptor tyrosine kinase A family members on Langerhans like dendritic cells
%A Else Munthe
%A Eivind Finne
%A Hans-Christian Aasheim
%J BMC Immunology
%D 2004
%I BioMed Central
%R 10.1186/1471-2172-5-9
%X In this study, expression of the EphA2 receptor was identified on in vitro generated Langerhans like dendritic cells compared to in vitro generated dendritic cells. We show that ligand induced engagement of the EphA2 receptor leads to receptor autophosphorylation indicating a functional receptor signaling pathway in these cells. We also observe phosphorylation and dephosphorylation of distinct proteins following ligand activation of EphA receptors. In co-stimulation assays, receptor-ligand interaction reduces the capacity of the Langerhans like dendritic cells to stimulate resting CD4+ T cells.Engagement of EphA receptor tyrosine kinases on Langerhans like dendritic cells induces signaling as shown by tyrosine phosphorylation and dephosphorylation of distinct proteins. Furthermore this engagement renders the cells less capable of stimulating CD4+ T cells.Immature dendritic cells are localized in tissues where they monitor the microenvironment and are characterized by their capacity to take up antigens. Dendritic cells must be activated by "danger signals" to become efficient antigen presenting cells [1-3]. This maturation process includes an efficient presentation of processed antigens by inducing cell surface expression of peptide loaded MHC molecules and an increased production of cytokines. Up-regulation of specific co-stimulatory and co-adhesive molecules, like CD80 and CD86, are also necessary to fully activate T cells. Finally, a potential to migrate to the lymph nodes is developed. The mature dendritic cell is thus equipped with a package of information that orchestrates the T cell response [4]. Dendritic cells can be divided into several groups, with different cellular origins, localization and capacity to stimulate a primary T cell response [1]. One group is the Langerhans cells, which are immature dendritic cells of myeloid origin resident in squamous epithelia, including skin and mucosa. These cells are characterized by high cell surface expression of CD1
%U http://www.biomedcentral.com/1471-2172/5/9