RESUMO
BACKGROUND: Previous work has identified CD11c(+)CD1c(-) dendritic cells (DCs) as the major "inflammatory" dermal DC population in patients with psoriasis vulgaris and CD1c(+) DCs as the "resident" cutaneous DC population. OBJECTIVE: We sought to further define molecular differences between these 2 myeloid dermal DC populations. METHODS: Inflammatory and resident DCs were single-cell sorted from lesional skin biopsy specimens of patients with psoriasis, and the transcriptome of CD11c(+)CD1c(-) versus CD1c(+) DCs was determined. Results were confirmed with RT-PCR, flow cytometry, immunohistochemistry, and double-labeled immunofluorescence. Human keratinocytes were cultured for functional studies. RESULTS: TNF-related apoptosis-inducing ligand (TRAIL), Toll-like receptors 1 and 2, S100A12/ENRAGE, CD32, and many other inflammatory products were differentially expressed in inflammatory DCs compared with resident DCs. Flow cytometry and immunofluorescence confirmed higher protein expression on CD1c(-) versus CD1c(+) DCs. TRAIL receptors, death receptor 4, and decoy receptor 2 were expressed in keratinocytes and dermal cells. In vitro culture of keratinocytes with TRAIL induced CCL20 chemokine. CONCLUSIONS: CD11c(+)CD1c(-) inflammatory DCs in psoriatic lesional skin express a wide range of inflammatory molecules compared with skin-resident CD1c(+) DCs. Some molecules made by inflammatory DCs, including TRAIL, could have direct effects on keratinocytes or other skin cell types to promote disease pathogenesis.
Assuntos
Biomarcadores/metabolismo , Células de Langerhans/metabolismo , Psoríase/diagnóstico , Psoríase/imunologia , Ligante Indutor de Apoptose Relacionado a TNF/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Diferenciação Celular , Separação Celular , Células Cultivadas , Quimiocina CCL20/biossíntese , Quimiocina CCL20/genética , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica , Inflamação , Queratinócitos/imunologia , Queratinócitos/metabolismo , Queratinócitos/patologia , Células de Langerhans/imunologia , Células de Langerhans/patologia , Análise em Microsséries , Psoríase/patologia , Proteínas S100/biossíntese , Proteínas S100/genética , Receptores Chamariz do Fator de Necrose Tumoral/biossíntese , Receptores Chamariz do Fator de Necrose Tumoral/genéticaRESUMO
To determine the phenotype and function of myeloid dendritic cells (DCs) from human cutaneous squamous-cell carcinoma (SCC), we studied their surface marker expression and allo-stimulatory potential ex vivo. There were abundant CD11c(+) myeloid DCs, as well as TNF and inducible nitric oxide synthase (iNOS)-producing DCs, in and around SCC tumor nests. Although myeloid DCs from SCC, adjacent non-tumor-bearing skin, and normal skin, were phenotypically similar by flow cytometry, and there was a pronounced genomic signature of mature DCs in SCC, they showed different T-cell stimulatory potential in an allogeneic mixed leukocyte reaction. Myeloid DCs from SCC were less potent stimulators of allogeneic T-cell proliferation than DCs from non-tumor-bearing skin. Culture with a DC-maturing cytokine cocktail (IL-1beta, IL-6, TNF-alpha, and PGE(2)) enhanced stimulatory potential in DCs from non-tumor-bearing skin, whereas SCC-associated DCs remained poor stimulators of T-cell proliferation. The microenvironment associated with SCC showed expression of TGF-beta, IL-10, and VEGF-A, factors capable of suppressing the DC function. These findings indicate that CD11c(+)/HLA-DR(hi) DCs from SCC are mature, but are not potent stimulators of T-cell proliferation compared with phenotypically similar DCs isolated from non-tumor-bearing skin. Identification of mechanisms responsible for suppression of tumor-associated DCs may provide insight into the evasion of immunosurveillance by SCC.