A postmigrational switch among skin-derived dendritic cells to a macrophage-like phenotype is predetermined by the intracutaneous cytokine balance.
Migration of dendritic cells (DC) to secondary lymphoid organs under proinflammatory conditions coincides with their maturation and acquisition of T cell stimulatory abilities. In contrast, impaired activation of DC, e.g., in tumor-conditioned environments, may hamper their activation and possibly their subsequent migration to lymph nodes, leading to either immunological tolerance or ignorance, respectively. In this study, the influence of cytokines in the peripheral skin microenvironment on the activation state of migrating cutaneous DC was assessed using an ex vivo human skin explant model. We observed a phenotypic shift from mature CD83(+) DC to immature CD14(+) macrophage-like cells within 7 days subsequent to migration from unconditioned skin. These macrophage-like cells displayed a poor T cell stimulatory ability and lacked expression of CCR7, thus precluding their migration to paracortical T cell areas in the lymph nodes. The balance of suppressive and stimulatory cytokines during the initiation of migration decided the postmigrational fate of DC with IL-10 accelerating and GM-CSF and IL-4 preventing the phenotypic switch, which proved irreversible once established. These observations indicate that, in immunosuppressed environments, a postmigrational DC-to-macrophage shift may hinder T cell activation, but also that it may be prevented by prior conditioning of the tissue microenvironment by GM-CSF and/or IL-4.
de Gruijl
Tanja D
TD
Department of Medical Oncology, Division of Immunotherapy, VU University Medical Center, Amsterdam, The Netherlands. td.degruijl@vumc.nl
Sombroek
Claudia C
CC
Lougheed
Sinéad M
SM
Oosterhoff
Dinja
D
Buter
Jan
J
van den Eertwegh
Alfons J M
AJ
Scheper
Rik J
RJ
Pinedo
Herbert M
HM
D015415:Biomarkers / Q000378:metabolism; D002454:Cell Differentiation / Q000276:immunology; D002465:Cell Movement / Q000276:immunology*; D049109:Cell Proliferation; D016207:Cytokines / Q000096:biosynthesis* / Q000502:physiology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology / Q000502:physiology; D006801:Humans; D016130:Immunophenotyping; D015847:Interleukin-4 / Q000494:pharmacology / Q000502:physiology; D007801:Langerhans Cells / Q000276:immunology / Q000378:metabolism; D018950:Lipopolysaccharide Receptors / Q000096:biosynthesis; D008264:Macrophages / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*; D009924:Organ Culture Techniques; D012867:Skin / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D013234:Stem Cells / Q000276:immunology / Q000378:metabolism
D015415:Biomarkers; D016207:Cytokines; D018950:Lipopolysaccharide Receptors; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor