title: Human afferent lymph from normal skin contains an increased number of mainly memory / effector CD4(+) T cells expressing activation, adhesion and co-stimulatory molecules.
abstract: We investigated the T cell population in the afferent lymph and the peripheral blood with regard to expression of activation, adhesion and co-stimulatory molecules and cytokine profile by immunohistochemistry and flow cytometry. The majority of the lymphoid cell population in the afferent lymph were CD4(+), CD45RO(+) T cells expressing the alpha beta TCR. An increased percentage of the T cells expressed activation molecules like HLA-DR, CD25, CD26, CD69 as well as adhesion and co-stimulatory molecules like CD54, CD154 / 40 ligand. Furthermore, T cells in the afferent lymph predominantly expressed the type 1 cytokine IFN-gamma, whereas type 2 cytokines such as IL-4, IL-5, IL-10 were not or barely detectable. Interestingly, dendritic cells expressing IL-12 were also found in close association with some lymphocytes, indicating that these contacts may be important in promoting Th 1 cells. In conclusion, an increased number of mainly CD4(+) memory / effector T cells, expressing activation, adhesion and co-stimulatory molecules migrate through the afferent skin-derived lymph in humans. Furthermore, our data demonstrate the dominance of a type 1 cytokine profile in these T cells and suggest that they have an important function in the immune surveillance against pathogens or other antigens in the skin and its associated lymphoid tissue.
authors.affiliation: Dermatological Clinic University of Bern, Inselspital, Bern, Switzerland. nikhil.yawalkar@insel-ch
authors.forename: N
authors.initials: N
authors.lastname: Yawalkar
authors.forename: R E
authors.initials: RE
authors.lastname: Hunger
authors.forename: W J
authors.initials: WJ
authors.lastname: Pichler
authors.forename: L R
authors.initials: LR
authors.lastname: Braathen
authors.forename: C U
authors.initials: CU
authors.lastname: Brand
mesh_terms: D015703:Antigens, CD / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000276:immunology; D006801:Humans; D007156:Immunologic Memory; D007378:Interleukins / Q000276:immunology; D008196:Lymph / Q000276:immunology*; D008213:Lymphocyte Activation; D012879:Skin Physiological Phenomena
chemical_list: D015703:Antigens, CD; D015815:Cell Adhesion Molecules; D007378:Interleukins