UVB radiation interrupts cytokine-mediated support of an epidermal-derived dendritic cell line (XS52) by a dual mechanism.
We have established long-term dendritic cell lines from the epidermis of newborn mice. These cell lines (XS series) proliferate maximally in response to granulocyte/macrophage-colony stimulating factor, as well as to CSF-1, which is produced by skin-derived NS fibroblast lines and by keratinocytes (albeit in smaller amounts). The purpose of this study was to examine the impact of UVB radiation on CSF-1-mediated interaction of dendritic cells with fibroblasts and keratinocytes. Exposure of NS cells to UVB radiation (unfiltered FS20 sunlamp) decreased CSF-1 production at mRNA and protein levels. Both changes occurred in a dose-dependent fashion, with 50 J/m2 causing a significant reduction. UVB radiation also downregulated CSF-1 mRNA expression by Pam 212 keratinocytes. UVB exposure of XS cells diminished the surface expression of CSF-1 receptors, with 50 J/m2 causing a significant reduction. Thus, UVB radiation interrupts CSF-1-mediated cell-cell interaction by a dual mechanism: downregulating CSF-1 production and abrogating CSF-1 receptor expression. Importantly, granulocyte/macrophage-colony stimulating factor receptor expression by XS cells was also inhibited by UVB radiation, once again, with 50 J/m2 producing significant inhibition. We propose that the resulting CSF-1 deficiency in epidermal microenvironment and unresponsiveness by dendritic cells to relevant growth factors may contribute to UVB-mediated loss of resident epidermal dendritic cells (i.e., Langerhans cells) in skin.
Schuhmachers
G
G
Department of Dermatology, University of Texas, Southwestern Medical Center, Dallas 75235-9069, USA.
Ariizumi
K
K
Kitajima
T
T
Edelbaum
D
D
Xu
S
S
Shadduck
R K
RK
Gilmore
G L
GL
Taylor
R S
RS
Bergstresser
P R
PR
Takashima
A
A
D000818:Animals; D002460:Cell Line; D003713:Dendritic Cells / Q000378:metabolism / Q000528:radiation effects*; D016173:Macrophage Colony-Stimulating Factor / Q000235:genetics / Q000502:physiology*; D051379:Mice; D012333:RNA, Messenger / Q000032:analysis; D016186:Receptor, Macrophage Colony-Stimulating Factor / Q000528:radiation effects; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor / Q000528:radiation effects; D014466:Ultraviolet Rays
D012333:RNA, Messenger; D016187:Receptors, Granulocyte-Macrophage Colony-Stimulating Factor; D016173:Macrophage Colony-Stimulating Factor; D016186:Receptor, Macrophage Colony-Stimulating Factor