title: IL-17-producing CD8+ T lymphocytes from psoriasis skin plaques are cytotoxic effector cells that secrete Th17-related cytokines.
abstract: IL-17-producing CD4+ T lymphocytes (Th17) are currently considered relevant participants in the pathogenesis of psoriasis skin lesions. However, little is known about the potential role of IL-17-producing CD8+ T cells, which are also present at the psoriatic plaque. We have addressed the functional characterization of this CD8+ subtype of T lymphocytes from psoriasis patients. Our results show that CD8+IL-17+ cells from psoriasis-inflamed skin tissue produce TNF-alpha and IFN-gamma (Th1-related cytokines) as well as IL-17, IL-21, and IL-22 (Th17-related cytokines) efficiently. A significant up-regulation of the RORC transcription factor is also observed. These cells are refractory to Tregs but show a proliferative response to anti-CD3/CD28 stimulation that is enhanced by IL-12 and IL-15. Blocking of TNF-alpha activity inhibits TCR-mediated activation and IL-17 production. CD8+IL-17+ T cells are cytotoxic cells that display TCR/CD3-mediated cytotoxic abilities to kill target cells. Thus, CD8+IL-17+ T cells share some key features with Th17 cells and exhibit remarkable differential abilities attributable to the CD8+ lineage of T lymphocytes, adding new insights into the functional resources of IL-17-producing cells from human epidermis that could be of potential interest to our understanding of the pathogenesis of psoriasis.
authors.affiliation: Unidad de Inmunología, Facultad de Medicina, Universidad de Córdoba, Córdoba, Spain.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Ortega
authors.forename: Silvia
authors.initials: S
authors.lastname: Fernández-A
authors.forename: Juan M
authors.initials: JM
authors.lastname: Carrillo
authors.forename: Pilar
authors.initials: P
authors.lastname: Romero
authors.forename: Ignacio J
authors.initials: IJ
authors.lastname: Molina
authors.forename: José C
authors.initials: JC
authors.lastname: Moreno
authors.forename: Manuel
authors.initials: M
authors.lastname: Santamaría
mesh_terms: D000906:Antibodies / Q000494:pharmacology; D018106:CD28 Antigens / Q000276:immunology; D017252:CD3 Complex / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D019070:Cell Lineage / Q000276:immunology; D016207:Cytokines / Q000378:metabolism*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D020381:Interleukin-17 / Q000378:metabolism*; D007378:Interleukins / Q000378:metabolism; D008213:Lymphocyte Activation / Q000187:drug effects; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; D011565:Psoriasis / Q000276:immunology* / Q000378:metabolism / Q000503:physiopathology; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000276:immunology* / Q000473:pathology / Q000503:physiopathology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000906:Antibodies; D018106:CD28 Antigens; D017252:CD3 Complex; D016207:Cytokines; D020381:Interleukin-17; D007378:Interleukins; D057132:Nuclear Receptor Subfamily 1, Group F, Member 3; C539900:RORC protein, human; D018168:Receptors, Retinoic Acid; D011988:Receptors, Thyroid Hormone; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma